CN107208203A - Hydrogen bearing alloy - Google Patents

Abstract

The present invention relates to hydrogen bearing alloy, its contain a) at least one principal phase, b) store it is secondary mutually and c) be catalyzed secondary phase, wherein the weight rate between the secondary phase abundance of catalysis and the secondary phase abundance of storage is >=3；Or contain a) at least one principal phase, b) 0 13.3 weight % storage is secondary mutually and c) is catalyzed secondary phase, wherein alloy contains 0.05 0.98at% one or more rare earth elements；Or alloy contains such as i) one or more elements and ii for being selected from Ti, Zr, Nb and Hf) one or more it is selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si, Sn and rare earth element element, wherein ii) and i) between atom ratio be about 1.80 1.98；This alloy has improved low temperature electrochemical performance.

Description

hydrogen storage alloy

The present invention relates to hydrogen storage alloys with improved electrochemical properties. Alloys are, for example, modified AB _x -type alloys, where x is about 0.5-5.

Alloys capable of absorbing and desorbing hydrogen can be used as hydrogen storage media and/or as electrode materials for solid hydrogen storage media, metal hydride batteries, fuel cells, metal hydride air battery systems, and the like. These materials are called metal hydride (MH) materials.

Efforts continue to improve the electrochemical performance of ABx MH alloys, which are used, for example, as active anode materials in batteries. Nickel metal hydride (NiMH) batteries are an environmentally friendly technology and have replaced toxic nickel cadmium (NiCd) batteries in all applications except those requiring low temperature discharge capability (eg <25°C). Further improvement of the low-temperature electrochemical performance of ABx metal hydride alloys would allow the complete exclusion of NiCd batteries from the consumer market.

It has surprisingly been found that certain metal hydride alloys show improved electrochemical performance, eg improved low temperature electrochemical performance.

This paper discloses a hydrogen storage alloy, which contains:

a) at least one main phase,

b) store the secondary phase, and

c) a catalytic secondary phase,

wherein the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≧3.

Also disclosed is a hydrogen storage alloy comprising:

a) at least one main phase,

b) optionally storing the secondary phase, and

c) a catalytic secondary phase,

The alloy contains 0.05-0.98 at% of one or more rare earth elements.

A hydrogen storage alloy is also disclosed which shows:

Compared to the AB ₂ alloy Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 at least 10% improvement in the surface catalytic ability at -40°C, defined as the charge transfer resistance ( R) and the product of the double layer capacitance (C); and/or

Charge transfer resistance ≤ 60Ω·g at -40°C; and/or

Surface catalytic ability at -40°C < 30 seconds, defined as the product of charge transfer resistance (R) and double layer capacitance (C).

Also disclosed is a hydrogen storage alloy comprising:

a) at least one main phase,

b) optionally storing the secondary phase, and

c) a catalytic secondary phase,

The alloy contains:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metals and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements,

wherein the atomic ratio between ii) and i) is about 1.80-1.98.

The hydrogen storage alloys of the present invention have improved electrochemical properties, such as improved low temperature electrochemical properties.

Detailed description of the invention

Alloys according to the invention are, for example, modified ABx-type metal hydride (MH) alloys, where, in general, A is a hydride-forming element and B is a weak or non-hydride-forming element. A is usually a larger metal atom with 4 or less bonding electrons and B is usually a smaller metal atom with 5 or more bonding electrons. Suitable ABx alloys include those where x is about 0.5-5. The alloys of the present invention are capable of reversibly absorbing (charging) and desorbing (releasing) hydrogen. For example, the alloys of the present invention are capable of reversibly absorbing and desorbing hydrogen electrochemically at ambient conditions (25°C and 1 atm).

ABx-type alloys are, for example, various types (simple example), AB (HfNi, TiFe, TiNi), AB ₂ (ZrMn ₂ , TiFe ₂ ), A ₂ B (Hf ₂ Fe, Mg ₂ Ni), AB ₃ (NdCo ₃ , GdFe ₃ ), A ₂ B ₇ (Pr ₂ Ni ₇ , Ce ₂ Co ₇ ) and AB ₅ (LaNi ₅ , CeNi ₅ ).

The alloys of the invention are obtained, for example, by modifying a base alloy of the ABx type (one A and one B element selected) with one or more modifying elements. Modification also includes judicious selection of metals and their atomic ratios, and control of processing parameters during curing, post-cure processing, annealing, machining or hydrogen storage alloy operations. Annealing can be done in vacuum, partial vacuum or inert gas environment, followed by natural wind, forced air or rapid cooling. Modification also includes activation techniques such as etching, pre-oxidation, electroless plating, and electroplating and coating. The etching step may comprise an alkaline and/or acidic etching process to selectively or preferentially etch one or more elements or oxides or hydroxides or phases in the interfacial range of the hydrogen storage alloy.

Prior to use, metal or metal alloy electrodes are typically subjected to activation, in which native surface oxides in the interfacial region are removed or reduced. Activation methods can be performed by etching, electroforming, preconditioning, or other methods suitable for modifying surface oxides. Activation can be applied to the electrode alloy powder, the final electrode, or anywhere in between.

The alloys of the present invention can be obtained by using a combination of the above techniques. The alloy to be modified according to the invention is the "base alloy".

Suitable modifying elements include rare earth elements, Si, Al and V. Rare earth elements are Sc, Y, La and lanthanides. The term "one or more rare earth elements" includes misch metals (Mm) (Mischmetal). The rare earth element is, for example, La.

Metal hydride base alloys include alloys containing Ti, V, and Mn (Ti-V-Mn alloys), and alloys containing Ti, V, and Fe. For example, the hydride of the alloy contains about 31-46 atomic % Ti, about 5-33 atomic % V, and about 36-53 atomic % Mn and/or Fe. Suitable alloys can be found, for example, in US Patent No. 4,111,689.

Metal hydride base alloys include alloys having the formula ABx, wherein A contains from about 50 atomic percent to less than 100 atomic percent Ti, the balance being Zr and/or Hf; and B contains from about 30 atomic percent to less than 100 atomic percent Ti Ni, and the rest are one or more elements selected from Cr, V, Nb, Ta, Mo, Fe, Co, Mn, Cu and rare earth elements; x is about 1-3. Such alloys can be found, for example, in US Patent No. 4,160,014.

Metal hydride base alloys include: alloys having the formula (TiV _2-x Ni _x ) _1-y M _y where x is about 0.2-1.0 and M is Al and/or Zr; alloys having the formula Ti _2-x Zr _x Alloys of V _4-y Ni _y , wherein x is from 0 to about 1.5, and y is from about 0.6 to 3.5; and alloys having the formula Ti _1-x Cr _x V _2-y Ni _y , wherein x is from 0 to about 0.75 , and y is about 0.2-1.0. These base alloys can be found, for example, in US Patent No. 4,551,400.

Metal hydride base alloys, for example, contain one or more elements selected from Mg, Ti, V, Zr, Nb, La, Si, Ca, Sc and Y, and one or more elements selected from Cu, Mn, Fe, Elements of Ni, Al, Mo, W, Ti, Re and Co. For example, the MH base alloy may contain one or more elements selected from Ti, Mg, and V, and contain Ni. Advantageously, the MH base alloy contains Ti and Ni, eg in an atomic range of about 1:4 to 4:1. Advantageously, the MH base alloy contains Mg and Ni, eg in an atomic range of about 1:2 to 2:1. Suitable base alloys can be found, for example, in US Patent No. 4,623,597.

Base alloys include those having the formula (Ti _2-x Zr _x V _4-y Ni _y ) _1-z Cr _z , where x is 0 to about 1.5, y is about 0.6-3.5, and z≤0.2. These base alloys can be found, for example, in US Patent No. 4,728,586.

The metal hydride base alloy contains, for example, V, Ti, Zr and Ni (Ti-V-Zr-Ni alloy), or contains V, Ti, Zr, Ni and Cr. For example, the MH base alloy contains Ti, V and Ni and one or more elements selected from Cr, Zr and Al. For example, MH base alloys include: V ₂₂ Ti ₁₆ Zr ₁₆ Ni ₃₉ Cr ₇ , (V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₉ Cr ₇ ) ₉₅ Al ₅ , (V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₉ Cr ₇ ) ₉₅ Mn ₅ , (V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₉ Cr ₇ ) ₉₅ Mo ₅ , (V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₉ Cr ₇ ) ₉₅ Cu ₅ , (V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₉ Cr ₇ ) ₉₅ W ₅ , (V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₉ Cr ₇ ) ₉₅ Fe ₅ , (V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₉ Cr ₇ ) ₉₅ Co ₅ , V ₂₂ Ti ₁₆ Zr ₁₆ N ₃₂ Cr ₇ Co ₇ , V _20.6 Ti ₁₅ Zr ₁₅ N ₃₀ Cr _6.6 Co _6.6 Mn _3.6 Al _2.7 and V ₂₂ Ti ₁₆ Zr ₁₆ N _27.8 Cr ₇ Co _5.9 Mn _3.1 Al _2.2 alloys. For example, MH base alloys include alloys having the formula (V _y'-y Ni _y Ti _x'-x Zr _x Cr _z ) _a M _b , where y' is about 3.6-4.4, y is about 0.6-3.5, x' is about 1.8-2.2, x is 0 to about 1.5, z is 0 to about 1.44, a is about 70-100, b is 0 to about 30, and M is one or more selected from Al, Mn, Mo, Elements of Cu, W, Fe and Co. These values are atomic percent (at %). Suitable MH base alloys can be found, for example, in US Patent No. 5,096,667.

Base alloys include those having the formula (metal alloy) _a Co _b Mn _c Fe _{d Sne} wherein (metal alloy) contains about 0.1-60 at % Ti, about 0.1-40 at % Zr, 0 to about 60 at % V , about 0.1-57at% Ni and 0 to about 56at% Cr; b is 0 to about 7.5at%, c is about 13-17at%, d is 0 to about 3.5at%, and e is 0 to about 1.5 at%, where a+b+c+d+e=100at%. Suitable MH base alloys can be found, for example, in US Patent No. 5,536,591.

Metal hydride base alloys include LaNi ₅ type alloys, alloys containing Ti and Ni, and alloys containing Mg and Ni. The alloy containing Ti and Ni may further contain one or more of Zr, V, Cr, Co, Mn, Al, Fe, Mo, La, or Mm (rare earth metal mischmetal). The alloy containing Mg and Ni can also contain one or more selected from Co, Mn, Al, Fe, Cu, Mo, W, Cr, V, Ti, Zr, Sn, Th, Si, Zn, Li, Cd, Elements of Na, Pb, La, Mm, Pd, Pt and Ca. Suitable base alloys can be found, for example, in US Patent No. 5,554,456.

Metal hydride base alloys are, for example, alloys based on LaNi ₅ or TiNi. For example, the MH base alloy includes one or more hydride-forming elements selected from Ti, V, and Zr, and one or more hydride-forming elements selected from Ni, Cr, Co, Mn, Mo, Nb, Fe, Al, Mg , Cu, Sn, Ag, Zn and Pd elements. For example, the MH base alloy contains one or more hydride-forming elements selected from Sc, Y, La, Ce, Pr, Nd, Sm, and Mm, and one or more elements selected from Ni, Cr, Co, Mn , Fe, Cu, Sn, Al, Si, B, Mo, V, Nb, Ta, Zn, Zr, Ti, Hf and W elements. The MH base alloy may include one or more elements selected from Al, B, C, Si, P, S, Bi, In, and Sb.

Base alloys include (Mg _x Ni _1-x ) _a M _b alloys, where M is one or more selected from the group consisting of Ni, Co, Mn, Al, Fe, Cu, Mo, W, Cr, V, Ti, Zr, Elements of Sn, Th, Si, Zn, Li, Cd, Na, Pb, La, Mm, Pd, Pt, and Ca; b is 0 to about 30 at%, a+b=100 at%, and x is about 0.25 -0.75.

Base alloys also include hydrides of alloys having the formula ZrModNie where _d is about 0.1-1.2 and _e is about 1.1-2.5.

Base alloys include alloys having the formula _ZrMnwVxMyNiz where M is Fe or Co, _w is about 0.4-0.8 at%, _x is about 0.1-0.3 at%, _y is 0 to about 0.2 at%, z is about 1-1.5 at%, and w+x+y+z is about 2-2.4 at%.

MH base alloys include alloys having the formula LaNi ₅ in which La or Ni is substituted by one or more metals other than the lanthanides selected from Groups Ia, II, III, IV and Va of the Periodic Table of the Elements, the atomic % is about 0.1-25.

MH base alloys include those having the formula TiV _2-x Ni _x , where x is about 0.2-0.6.

MH base alloys also include alloys having the formula Ti _a Zr _b Ni _c Cr _d M _x , where M is one or more selected from the group consisting of Al, Si, V, Mn, Fe, Co, Cu, Nb, Ag and Pd Elements, a is about 0.1-1.4, b is about 0.1-1.3, c is about 0.25-1.95, d is about 0.1-1.4, x is 0 to about 0.2, and a+b+c+d=about 3.

MH base alloys include alloys having the formula Ti _1-x Zr _x Mn _2-yz Cr _y V _z , where x is about 0.05-0.4, y is 0 to about 1.0, and z is 0 to about 0.4.

MH base alloys also include those having the formula LnM ₅ , where Ln is one or more lanthanides and M is Ni and/or Co.

The base alloy contains, for example, about 40-75% by weight of one or more elements selected from Groups II, IV and V of the Periodic Table of the Elements and one or more elements selected from Ni, Cu, Ag, Fe and Cr-Ni steel Metal.

The MH base alloy may also contain the main structure Mm-Ni system. Base alloys suitable for modification can be found, for example, in US Patent No. 5,840,440.

Metal hydride base alloys contain, for example, V, Ti, Zr, Ni, Cr and Mn. For example, the MH base alloy contains V, Ti, Zr, Ni, Cr, Mn, and Al; contains V, Ti, Zr, Ni, Cr, Mn, and Sn; contains V, Ti, Zr, Ni, Cr, Mn, and Co; Contains V, Ti, Zr, Ni, Cr, Mn, Al, Sn and Co; or contains V, Ti, Zr, Ni, Cr, Mn, Al, Sn, Co and Fe. MH base alloys include alloys having the formula (metal alloy) _a Co _b Fe _c Al _{d Sne} wherein (metal alloy) contains about 0.1-60 at % Ti, about 0.1-40 at % Zr, 0 to about 60 at % V, about 0.1-57 at% Ni, about 5-22 at% Mn and 0 to about 56 at% Cr, b is about 0.1-10 at%, c is 0 to about 3.5 at%, d is about 0.1-10 at% , e is about 0.1-3 at%, and a+b+c+d+e=100 at%. Suitable MH base alloys can be found, for example, in US Patent No. 6,270,719.

Metal hydride base alloys include one or more alloys selected from AB, AB ₂ , AB ₅ and A ₂ B-type alloys, where A and B can be transition metals, rare earth elements, or combinations thereof, where component A typically has Stronger tendency to form hydrides than component B. In the AB hydrogen storage basic alloy, A contains, for example, one or more elements selected from Ti, Zr and V, and B contains one or more elements selected from Ni, V, Cr, Co, Mn, Mo, Nb, Al , Mg, Ag, Zn and Pd elements. AB base alloys include ZrNi, ZrCo, TiNi, TiCo and their modified forms. A2B _- type base alloys include Mg2Ni and modified forms according to Ovshinsky's principle, wherein one or _both of Mg and Ni are fully or partially replaced by multi-orbital modifiers. AB Type ₂ base alloys are Laves phase compounds and include alloys in which A contains one or more elements selected from Zr and Ti and B contains one or more elements selected from Ni, V, Cr, Mn, Co, Mo , Ta and Nb elements. AB Type ₂ base alloys include alloys modified according to the Ovshinsky principle. AB ₅ metal hydride base alloys include those in which A contains one or more elements selected from the lanthanides and B contains one or more transition metals. Including LaNi ₅ ; and LaNi ₅ , wherein Ni is partially replaced by one or more elements selected from Mn, Co, Al, Cr, Ag, Pd, Rh, Sb, V and Pt, and/or wherein La is partially replaced by one or more elements selected from Ce, Pr, Nd, other rare earth elements and Mm. Also included are base alloys of type AB ₅ modified according to the Ovshinsky principle. These base alloys can be found, for example, in US Patent No. 6,830,725.

Base alloys include TiMn type ₂ alloys. For example, metal hydride base alloys contain Zr, Ti, V, Cr and Mn, where Zr is about 2-5 at%, Ti is about 26-33 at%, V is about 7-13 at%, and Cr is about 8-20 at% , and Mn is about 36-42at%. These alloys may further include one or more elements selected from Ni, Fe and Al, for example about 1-6 at % Ni, about 2-6 at % Fe and about 0.1-2 at % Al. These base alloys may also contain up to 1 at % of Mm. Alloys suitable for modification include: Zr _3.63 Ti _29.8 V _8.82 Cr _9.85 Mn _39.5 Ni _2.0 Fe _5.0 Al _1.0 Mm _0.4 ; Zr _{3.6 Ti 29.0} V _{8.9 Cr 10.1} Mn _40.1 Ni _2.0 Fe _5.1 Al _{1.2 ;} Cr _10.0 Mn _40.7 Ni _1.9 Fe _5.1 Al _1.6 , and Zr ₁ Ti ₃₃ V _12.54 Cr ₁₅ Mn ₃₆ Fe _2.25 Al _0.21 . Suitable base alloys can be found, for example, in US Patent No. 6,536,487.

Metal hydride base alloys may contain 40 at% or more of the A ₅ B ₁₉ type structure with the formula La _a R _1-ab Mg _b Ni _cde , where 0 ≤ a ≤ 0.5 at%, 0.1 ≤ b ≤ 0.2 at%, 3.7≤c≤3.9 at %, 0.1≤d≤0.3, and 0≤d≤0.2. Suitable base alloys can be found, for example, in US Patent No. 7,829,220.

The alloy of the present invention may be in the form of hydrogen-absorbing alloy particles containing at least Ni and rare earth elements. These particles may have a surface layer and an interior, wherein the surface layer has a greater nickel content than the interior, and nickel particles having a particle size of about 10-50 nm are present in the surface layer. Metal hydride base alloys may have the formula Ln _1-x Mg _x Ni _abc Al _b Z _c , where Ln is one or more rare earth elements and Z is Zr, V, Bn, Ta, Cr, Mo, Mn, Fe, One or more of Co, Ga, Zn, Sn, In, Cu, Si, P, and B, 0.05≤x≤0.3at%, 2.8≤a≤3.9at%, 0.05≤b≤0.25at%, and 0.01≤c≤0.25. Suitable base alloys can be found, for example, in US Patent No. 8,053,114.

The alloy of the present invention may have a multiphase crystal structure containing at least an _{A2B7 -} type structure and an _{A5B19 -} type structure and have a surface layer wherein the nickel content of the surface layer is greater than that of the bulk. Metal hydride base alloys include alloys having the formula _{Ln 1-x} Mg _x Ni _yab Ala M _b , where Ln is one or more rare earth elements, including Y, and M is one or more of Co, Mn and Zn species, where 0.1≤x≤0.2at%, 3.5≤y≤3.9at%, 0.1≤a≤0.3at%, and 0≤b≤0.2. Suitable base alloys can be found, for example, in US Patent No. 8,124,281.

The metal hydride base alloy may have the formula Ln _1-x Mg _x (Ni _{1-y Ty} ) _z , where Ln is one or more selected from the group consisting of lanthanides, Ca, Sr, Sc, Y, Ti, Zr and An element of Hf, T is one or more elements selected from the group consisting of V, Nb, Ta, Cr, Mo, Mn, Fe, Co, Al, Ga, Zn, Sn, In, Cu, Si, P, and B, and where 0<x≤1at%, 0≤y≤0.5at%, and 2.5≤z≤4.5at%. Suitable base alloys can be found, for example, in US Patent No. 8,257,862.

The alloy of the present invention may contain La, Nd, Mg, Ni and Al; contain La, Nd, Mg, Ni, Al and Co; contain La, Pr, Nd, Mg, Ni and Al, or contain La, Ce, Pr, Nd, Ni, Al, Co and Mn, as described in US Patent No. 8,409,753.

The metal hydride base alloy may have the formula Ti _A Zr _BX Y _X V _C Ni _D M _E , wherein each of A, B, C, and D is greater than 0 and less than or equal to 50 at%, X is greater than 0 and less than or equal to 4 at% , M is one or more metals selected from Co, Cr, Sn, Al and Mn, and E is 0-30 at%. Suitable base alloys can be found, for example, in USPub. No. 2013/0277607.

_The alloys of the present invention include modified _A2B7 type hydrogen storage alloys. For example, the MH base alloy may be an A _x B _y alloy, wherein A includes at least one rare earth element and also includes Mg; B includes at least Ni, and the atomic ratio of x:y is about 1:2 to 1:5, such as about 1:3 to 1:4. The MH base alloy may also contain one or more elements selected from B, Co, Cu, Fe, Cr and Mn. The atomic ratio between Ni and other elements may be about 50:1 to 200:1. Rare earth elements include La, Ce, Nd, Pr and Mm. The atomic ratio between the rare earth element and Mg may be about 5:1 to 6:1. The B element may further include Al, wherein an atomic ratio between Ni and Al may be about 30:1 to 40:1.

Metal hydride base alloys include ABx high capacity hydrogen storage alloys, where x is about 0.5-5, and which have a release capacity of >400mAh/g, >425mAh/g, >450mAh/g or >475mAh/g.

Metal hydride base alloys include high capacity MH alloys containing magnesium (Mg), such as AB, AB ₂ or A ₂ B type alloys containing Mg and Ni. For example, MH base alloys include MgNi, _MgNi2 and _Mg2Ni . This alloy containing Mg and Ni may further contain one or more elements selected from rare earth elements and transition metals. For example, an alloy containing Mg and Ni may further contain one or more selected from the group consisting of Co, Mn, Al, Fe, Cu, Mo, W, Cr, V, Ti, Zr, Sn, Th, Si, Zn, Li, Elements of Cd, Na, Pb, La, Ce, Pr, Nd, Mm, Pd, Pt, Nb, Sc and Ca.

For example, the MH base alloy contains Mg and Ni and optionally one or more selected from the group consisting of Co, Mn, Al, Fe, Cu, Mo, W, Cr, V, Ti, Zr, Sn, Th, Si, Zn, Elements of Li, Cd, Na, Pb, La, Ce, Pr, Nd, Mm, Pd, Pt, Nb, Sc and Ca.

Mm is "mixture of rare earth metals". Machetes are mixtures of rare earth elements. For example, Mm is a mixture containing La, Nd, and Pr, for example, Ce, La, Nd, and Pr.

For example, MH base alloys include MgNi, Mg _0.8 Ti _0.2 Ni, Mg _0.7 Ti _0.3 Ni, Mg _0.9 Ti _0.1 Ni, Mg _0.8 Zr _0.2 Ni, Mg _0.7 Ti _0.225 La _0.075 Ni, Mg _0.8 Al _0.2 Ni, Mg _0.9 Ti _0.1 Ni, Mg _0.9 Ti _0.1 NiAl _0.05 , Mg _0.08 Pd _0.2 Ni, Mg _0.09 Ti _0.1 NiAl _0.05 , Mg _0.09 Ti _0.1 NiAl _0.05 Pd _0.1 , Mg ₅₀ Ni _{45 Pd 5} , Mg _0.85 Ti _0.15 , Mg1 ₅ Ni _0.9 , Mg ₂ Ni, Mg _2.0 Ni _0.6 Co _0.4 , Mg ₂ Ni _0.6 Mn _0.4 , Mg ₂ Ni _0.7 Cu _0.3 , Mg _0.8 La _0.2 Ni, Mg _2.0 Co _0.1 Ni, Mg _2.1 Cr _0.1 Ni, Mg _2.0 Nb _0.1 Ni, Mg _2.0 Ti _0.1 Ni, Mg 2.0V _0.1 Ni, Mg _1.3 Al _0.7 Ni, Mg _1.5 Ti _0.5 Ni, Mg _1.5 Ti _0.3 Zr _0.1 Al _0.1 Ni _, Mg _1.75 Al _0.25 Ni and (MgAl) ₂ Ni, Mg _1.70 Al _0.3 Ni.

For example, MH base alloys include alloys of Mg and Ni, wherein the atomic ratio between Mg and Ni is about 1:2 to 2:1, and also contain one or more elements selected from the group consisting of Co, Mn, Al, Fe, Cu, Elements of Mo, W, Cr, V, Ti, Zr, Sn, Th, Si, Zn, Li, Cd, Na, Pb, La, Ce, Pr, Nd, Mm, Pd, Pt, Nb, Sc and Ca. The other element or elements may be present in an amount of about 0.1-30 atomic percent (at%) or about 0.25-15 at%, or about 0.5 at%, about 1 at%, about 2 at%, about 3 at%, about 4 at% Or about 5 at% to about 15 at%, based on the total amount of the alloy. The atomic ratio between Mg and Ni is, for example, about 1:1. Thus, Mg and Ni together may be present in an amount of about 70-99.9 at%, based on the total amount of the alloy. The Mg-Ni MH base alloy may be free of other elements, where Mg and Ni together are present in an amount of 100 at%.

The metal hydride base alloy may contain Mg and Ni in an atomic ratio of about 1:2 to 2:1, wherein Mg and Ni together are present in an amount > 70 at % based on the total amount of the alloy.

The metal hydride base alloy may contain > 20 at % Mg.

The metal hydride base alloy may contain Mg and Ni in an atomic ratio of about 1:2 to 2:1, and may also contain Co and/or Mn. The alloys of the present invention include modified Mg ₅₂ Ni ₃₉ Co ₆ Mn ₃ or modified Mg ₅₂ Ni ₃₉ Co ₃ Mn ₆ .

The metal hydride base alloy may contain > 90% by weight Mg and one or more additional elements. One or more additional elements may be selected from Ni, Mm, Al, Y and Si. These alloys may contain, for example, about 0.5-2.5 wt. % Ni and about 1.0-4.0 wt. % Mm. These alloys may also contain about 3-7% by weight Al and/or about 0.1-1.5% by weight Y and/or about 0.3-1.5% by weight Si.

Suitable high capacity MH base alloys can be found, for example, in US Patent Nos. 5,A506,069, 5,616,432 and 6,193,929.

Alloys of the invention are, for example, capable of storing at least 6% by weight of hydrogen and/or absorbing at least 80% of their total hydrogen storage capacity at 300° C. within 5 minutes; Absorb 80% of the total hydrogen storage capacity at °C; or be capable of storing at least 6.9% by weight of hydrogen and/or capable of absorbing 80% of the total hydrogen storage capacity at 300°C within 1.5 minutes.

Metal hydride base alloys include alloys having the formula Ti _a Zr _bx Y _x V _c Ni _{d Me} where a, b, c, and d are each greater than 0 and less than or equal to 50 at %, and x is greater than 0 and less than or equal to 4 at %, M is one or more metals selected from Co, Cr, Sn, Al and Mn, and e is 0 to about 30 at%. These alloys can be found, for example, in USPub. No. 2013/0277607.

The alloys of the invention can be prepared, for example, via arc melting or induction melting under an inert atmosphere, by melt casting, rapid solidification, mechanical alloy processing, sputtering or gas atomization, or other methods, as described in the above references.

Unless otherwise stated, elemental content in an alloy or phase is in atomic percent (at %), based on the total alloy or phase.

Unless otherwise stated, the amount of each phase is in weight percent (wt %), based on the total amount of the alloy.

The low-temperature electrochemical performance can be defined as the catalytic ability of the surface at low temperature, such as −40 °C. Surface catalytic ability is defined as the product of charge transfer resistance (R) and double layer capacitance (C), R·C. Values for R and C were calculated from curve fitting of Cole-Cole plots of AC impedance measurements.

Alternatively, low temperature electrochemical performance can be defined by the charge transfer resistance (R) at -40°C.

Low temperature is eg defined as <25°C, ≤10°C, ≤0°C, ≤-10°C, ≤-20°C or ≤-30°C.

The charge transfer resistance (R) is measured in terms of Ω·g. Double layer capacitance (C) is measured in terms of Farad/g (F/g).

AC impedance testing was performed using a SOLARTRON 1250 frequency response analyzer with a sine wave with an amplitude of 10 mV and a frequency of 10 mHz to 10 kHz. Prior to testing, electrodes were subjected to a full charge/discharge cycle at C/10 rate using a SOLARTRON 1470 Cell Test galvanostat, then recharged to 100% state of charge (SOC), then discharged to 80% (SOC), and finally Cool to -40°C. Two more cycles of AC impedance detection were repeated at room temperature and -40°C.

It was found that the ratio of the two different secondary phases can be advantageously optimized by adjusting the stoichiometry of the ABx alloy. For example, the alloy of the present invention is an AB ₂ type alloy modified with a low content of rare earth elements and designed so that the B/A ratio will be below 2.0.

The surface catalytic ability of the inventive alloy at -40°C is improved, for example, by at least ₁₀ %, relative to the comparative AB ₂ alloy, such as Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 . For example, the surface catalytic ability at -40°C is improved by at least 15%, at least 20%, at least 25%, at least 30%, at least 35% or at least 40% relative to a comparative AB ₂ alloy such as Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 . Details on detection can be found in the Examples. AB ₂ alloy Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 was prepared in the examples herein.

The surface catalytic ability of the alloy of the present invention at -40°C is, for example, ≤30 seconds, ≤25 seconds, ≤20 seconds, ≤15 seconds, ≤12 seconds, ≤10.0 seconds, ≤9.0 seconds, ≤8.0 seconds, ≤7.0 seconds, ≤6.0 seconds or ≤5.0 seconds.

For example, the surface catalytic capability of the alloy at -40°C is about 5-10 seconds, about 5-9 seconds, about 5-8 seconds or about 5-7 seconds.

The charge transfer resistance (R) at -40°C is, for example, ≤60Ω·g, ≤55Ω·g, ≤50Ω·g, ≤45Ω·g, ≤40Ω·g, ≤37Ω·g, ≤35Ω·g, ≤ 30Ω·g, ≤28Ω·g, ≤26Ω·g, ≤24Ω·g, ≤22Ω·g, ≤20Ω·g, ≤18Ω·g, ≤16Ω·g or ≤15Ω·g.

For example, the charge transfer resistance (R) at -40°C is about 10-20Ω·g, about 13-28Ω·g, about 14-26Ω·g, about 15-25Ω·g or about 15-24Ω·g.

Alloys contain at least one major phase and at least one secondary phase. The at least one primary phase, the storage secondary phase and the catalytic secondary phase each have a different chemical composition and/or physical structure. The physical structure is crystalline and amorphous. Phase abundance can be detected by X-ray diffraction (XRD). The composition of the phases can be examined with a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS).

The total amount of one or more primary phases is present in a higher abundance by weight than each secondary phase. _The one or more major phases are typically ABx phases, eg AB, _AB2 , _AB3 , _A2B7 or _AB5 phases.

Advantageously, the structure of each phase is different. That is, each phase has a structure selected from a crystalline structure and a non-crystalline (amorphous) structure, wherein each phase is different.

The hydrogen storage alloys of the present invention are, for example, modified ABx-type alloys, where x is about 0.5-5.

For example, the alloy of the present invention is a modified AB ₂ type alloy in which the atomic ratio between ii) and i) is about 1.80-2.20. The atomic ratio between ii) and i) may advantageously be about 1.80-1.98, about 1.80-1.95, or about 1.82-1.93.

In the present invention, the atomic ratio between ii) and i) is, for example, about 1.80, about 1.81, about 1.82, about 1.83, about 1.84, about 1.85, about 1.86, about 1.87, about 1.88, about 1.89, about 1.90, About 1.91, about 1.92, about 1.93, about 1.94, about 1.95, about 1.97, about 1.98 or about 1.99.

In the present invention, the modified AB ₂ type alloy contains, for example, a C14 or C15 major Laves phase, or a C14 and C15 major Laves phase. The weight abundance of the C14 phase is, for example, about 70-95, such as about 80-90 or about 83-88. The abundance of the C15 phase is, for example, about 2-20, about 3-15, or about 3-13 by weight, based on the alloy.

For example, alloys of the invention contain a C14 or C15 major Laves phase, or a C14 and C15 major Laves phase, and wherein the catalytic secondary phase and the storage secondary phase are non-Laves phases.

The weight abundance of the catalytic secondary phase is, for example, about 1-40, such as about 3-20. The abundance of the catalytic secondary phase can be about 4, about 5, about 6, about 7, about 8, about 9 or about 10 by weight based on the alloy.

The weight abundance of the storage secondary phase is for example 0 to about 13.3, for example >0 and ≦13.3, for example about 0.1-13.3, about 0.1-10, about 0.1-7 or about 0.1-5. The abundance of the first secondary phase can be about 0.5, about 0.8, about 1.1, about 1.4, about 1.7, about 2.0 or about 2.3 and values therebetween, by weight based on the alloy.

Advantageously, the alloy comprises about 2-10 wt%, about 3-9 wt%, or about 3-8 wt% catalytic secondary phase comprising Ti and Ni, and 0 to about 2 wt%, about 0.01-1.5 wt% Or about 0.05-1.3% by weight of storage secondary phases containing Y and Ni, based on the total amount of the alloy.

In general, across a range of alloys with similar compositions, the low-temperature electrochemical performance improves as the weight ratio between the abundance of catalytic and storage secondary phases increases. The weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is advantageously ≥3 or ≥4, eg ≥5, ≥6 or ≥7. This is the case when both a storage secondary phase and a catalytic secondary phase are present.

Advantageously, the weight ratio between the catalytic secondary phase and the storage secondary phase is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

The catalytic secondary phase advantageously has a TiNi(B2) crystal structure. That is, the crystal structure of the catalytic secondary phase is advantageously the well-known crystal structure of TiNi(B2), as determined by X-ray diffraction (XRD). In order to have the known TiNi(B2) crystal structure, it is not necessary for the catalytic secondary phase to contain Ti and/or Ni.

The catalytic secondary phase may contain Ti and/or Ni.

The catalytic secondary phase contains, for example, one or more elements selected from Ti, Zr, Nb and Hf, and also Ni. The catalytic secondary phase contains, for example, Ti and Ni, or Ti, Zr and Ni.

The catalytic secondary phase contains, for example, about 13-45 at% Ti, about 15-30 at% Ti, or about 15-25 at% Ti.

The catalytic secondary phase contains, for example, about 5-30 at% Zr, about 15-28 at% Zr, or about 20-26 at% Zr.

The catalytic secondary phase contains, for example, about 38-60 at% Ni, about 40-55 at% Ni, or about 45-50 at% Ni.

The crystal structures of the catalytic secondary phases of the present invention containing the above Ti and Ni contents are the well known TiNi(B2) crystal structures, but they may contain significant amounts of other metals such as Zr dissolved in the TiNi phase.

For example, the catalytic secondary phase contains about 45-49 at% Ni, about 17-22 at% Ti, and about 20-24 at% Zr, where (Ti+Zr) is about 41-43 at%. Advantageously, the at% of Zr is > at% of Ti when present together in the catalytic secondary phase. For example, the at% of Zr is > the at% of Ti when present together in the catalytic secondary phase.

The storage secondary phase has, for example, a different structure than the catalytic secondary phase.

The storage secondary phase contains, for example, one or more rare earth elements. The storage secondary phase, for example, contains Ni, contains one or more rare earth elements and Ni, contains one or more rare earth elements, Ni and Sn, contains Y and Ni, or contains Y, Ni and Sn.

For example, the storage secondary phase contains about 15-55 at%, about 20-50 at%, about 25-45 at%, or about 30-40 at% of one or more rare earth elements. For example, the storage secondary phase contains about 30-50 at % or about 30-40 at % of one or more rare earth elements. The rare earth element is Y, for example.

The storage secondary phase contains, for example, about 15-50 at % Ni, about 20-40 at % Ni, or about 20-30 at % Ni.

The storage secondary phase may contain, for example, about 15-32 at % Sn, about 18-30 at % Sn, or about 20-29 at % Sn.

For example, the storage secondary phase contains about 32-38 at% Y, about 21-27 at% Ni, and about 20-28 at% Sn.

Without being bound by any theory, it is believed that the secondary storage phase is capable of reversibly storing and releasing hydrogen like the primary (storage) phase, while the secondary catalytic phase "catalytic phase" serves to assist the primary phase and/or storage phase.

These different phases are believed to co-operate together. One phase with weaker metal-hydrogen bonds will act as a catalyst while the other phase acts as a hydrogen storage phase. Hydrogen in one or more storage phases can be more easily removed with the assistance of the catalytic phase.

The secondary storage phase is optional, and the modified alloys of the invention containing at least a catalytic secondary phase also exhibit outstanding electrochemical performance. For example, where the modification is via the addition of low levels of specific elements, these elements may be in solid solution in the main phase rather than forming an additional detectable storage phase.

"Modification" in the present invention promotes the formation of the catalytic phase.

Herein, atomic percentages (at%) mentioned with respect to each phase are based on this phase.

Herein, atomic percentages (at %) mentioned with respect to alloys are based on the total amount of the alloy.

Rare earth elements are Sc, Y, La and lanthanides. The term "one or more rare earth elements" includes misch metals (Mm). The rare earth element is Y, for example.

The alloy of the present invention contains, for example, about 0.05-10.0 at % of one or more rare earth elements, or about 0.1-7.0 at %, about 0.2-5.0 at % or about 0.2-2.0 at % of one or more rare earth elements , based on the alloy.

The alloys of the present invention may advantageously contain about 0.05 at%, about 0.1 at%, about 0.15 at%, about 0.20 at%, about 0.25 at%, about 0.30 at%, about 0.35 at%, about 0.40 at%, about 0.45 at% at%, about 0.50at%, about 0.55at%, about 0.60at%, about 0.65at%, about 0.70at%, about 0.75at%, about 0.80at%, about 0.85at%, about 0.90at%, about 0.95 at % or about 0.98 at % of one or more rare earth elements, based on the alloy, and values therebetween.

The alloy of the present invention contains, for example, Ti, Zr, V, Ni and one or more rare earth elements. The alloy of the present invention may contain Ti, Zr, Ni, Mn and one or more rare earth elements. The alloys of the present invention may contain Ti, Cr, V, Ni and one or more rare earth elements.

The alloy of the present invention contains, for example, Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn and Al. The alloy of the present invention contains, for example, Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and one or more rare earth elements. For example, the alloy of the present invention contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and Y.

For example, the alloy of the present invention contains about 0.1-60% Ti, about 0.1-40% Zr, 0<V<60%, 0 to about 56% Cr, about 5-22% Mn, about 0.1-57 % Ni, about 0.1-3% Sn, about 0.1-10% Al, about 0.1-11% Co, and about 0.1-10% one or more rare earth elements, where percentages are atomic % and total Equal to 100%.

Alloys are also disclosed containing about 5-15% Ti, about 18-29% Zr, about 3.0-13% V, about 1-10% Cr, about 6-18% Mn, about 29-41% Ni, about 0.1-1% of Sn, about 0.1-0.7% of Al, about 2-11% of Co, and about 0.2-5% of one or more rare earth elements, wherein the percentages are atomic % and the total amount is equal to 100%.

Advantageously, the alloy contains about 11-13% Ti, about 21-23% Zr, about 9-11% V, about 6-9% Cr, about 6-8% Mn, about 31-34% Ni, about 0.2-0.4% of Sn, about 0.3-0.6% of Al, about 2-8% of Co, and about 0.2-2.0% of one or more rare earth elements, wherein the percentages are atomic % and the total is equal to 100%.

The alloy of the present invention is capable of reversibly absorbing and desorbing hydrogen, for example at 25°C, 0°C, -20°C and/or -40°C.

A subject-matter of the invention is also a metal hydride cell, an alkaline fuel cell or a metal hydride-air cell comprising electrodes comprising a hydrogen storage alloy according to the invention.

Another subject of the invention is a metal hydride battery comprising at least one anode capable of reversibly charging and releasing hydrogen, at least one cathode capable of reversibly oxidizing, a housing containing said anode and cathode, for separating cathode and anode The separator, and the electrolyte in contact with both the anode and the cathode, wherein the anode contains the hydrogen storage alloy of the present invention.

The battery of the present invention is capable of charging a large amount of hydrogen at one polarity and releasing a desired amount of hydrogen at the opposite polarity.

Another subject of the invention is an alkaline fuel cell comprising at least one hydrogen electrode, at least one oxygen electrode and at least one gas diffusion material, wherein the hydrogen electrode contains a hydrogen storage alloy according to the invention.

Another subject of the invention is a metal hydride-air battery comprising at least one air-permeable cathode, at least one anode, at least one air inlet, and an electrolyte in contact with both the anode and the cathode, wherein the anode contains the inventive hydrogen storage alloy.

The term "a" referring to an element of an embodiment may mean "one" or "one or more".

The term "about" refers to variations that can occur, for example, by typical measuring and handling procedures, by inadvertent errors in these procedures, by differences in the manufacture, source or purity of ingredients used, by differences in the methods employed, and the like. The term "about" also includes amounts that vary due to the different equilibrium conditions of the composition obtained from the particular initial mixture. Whether or not modified by the term "about", the embodiments and claims include equivalents to the stated amounts.

All numerical values herein, whether expressly stated or not, are modified by the term "about". The term "about" generally refers to a range of numbers that one of ordinary skill in the art would consider equivalent to the stated value (ie, having the same function and/or result). In many instances, the term "about" may include figures that are rounded to the nearest significant figure.

A value modified by the term "about" certainly includes the specified value. For example, "about 5.0" must include 5.0.

The term "consisting essentially of" means that the composition, method or structure may contain additional components, steps and/or components, but the additional components, steps and/or components do not materially affect the claimed composition , fundamental and novel features of a method or structure.

The US patents, US patent application publications, and US patent applications mentioned herein are each incorporated herein by reference.

The following are some embodiments of the invention.

E1. A hydrogen storage alloy, for example with improved low temperature electrochemical properties, comprising:

a) at least one main phase,

b) store the secondary phase, and

c) a catalytic secondary phase,

where the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≥3, ≥4, ≥5, ≥6, or ≥7, or where the abundance of the catalytic secondary phase to the abundance of the storage secondary phase The weight ratio between is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8;

wherein the total amount of one or more major phases is present in a higher abundance by weight than each secondary phase, and wherein one or more major phases are, for example, ABx phases, such as AB, AB ₂ , AB _3. A ₂ B ₇ or AB ₅ phases;

For example, wherein the secondary catalytic phase catalyzes reversible electrochemical hydrogen charge/release reactions in the primary phase and/or the storage phase.

E2. The alloy according to embodiment 1, comprising:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metals and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements,

wherein the atomic ratio between ii) and i) is about 1.80-2.20.

E3. The alloy according to embodiment 2, wherein the atomic ratio between ii) and i) is about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93; or about 1.80, about 1.81, about 1.82, about 1.83, About 1.84, about 1.85, about 1.86, about 1.87, about 1.88, about 1.89, about 1.90, about 1.91, about 1.92, about 1.93, about 1.94, about 1.95, about 1.97, about 1.98 or about 1.99.

E4. The alloy according to any one of the preceding embodiments, which contains C14 and C15 major Laves phases, wherein the weight abundance of the C14 phase is about 70-95, about 80-90, or about 83-88, and the C15 phase abundance is according to About 2-20, about 3-15, or about 3-13 by weight, based on the alloy.

E5. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase has a TiNi(B2) crystal structure.

E6. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase contains one or more elements selected from Ti, Zr, Nb and Hf, and also contains Ni.

E7. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase contains about 13-45 at % Ti, about 15-30 at % Ti, or about 15-25 at % Ti, about 5-30 at % Zr, about 15-28 at% Zr or about 20-26 at% Zr, and about 38-60 at% Ni, about 40-55 at% Ni or about 45-50 at% Ni.

E8. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase abundance is ≥ 3 and ≤ 40% by weight; or the weight abundance of the catalytic secondary phase is about 1-40, about 3-20 by weight , or about 4, about 5, about 6, about 7, about 8, about 9, or about 10, based on the alloy.

E9. The alloy according to any one of the preceding embodiments, wherein the storage secondary phase contains one or more rare earth elements; contains Ni; contains one or more rare earth elements and Ni; contains one or more rare earth elements, Ni and Sn; contains Y and Ni, or contains Y, Ni and Sn.

E10. The alloy according to any one of the preceding embodiments, wherein the storage secondary phase contains about 15-55 at%, about 20-50 at%, about 25-45 at%, or about 30-40 at% of one or more rare earth elements; or The storage secondary phase contains about 30-50 at % or about 30-40 at % of one or more rare earth elements; and wherein the storage secondary phase contains about 15-50 at % Ni, about 20-40 at % Ni or about 20 -30at% Ni.

E11. The alloy according to any one of the preceding embodiments, wherein the storage secondary phase contains about 15-32 at % Sn, about 18-30 at % Sn, or about 20-29 at % Sn.

E12. The alloy according to any one of the preceding embodiments, wherein the storage secondary phase contains about 32-38 at % Y, about 21-27 at % Ni and about 20-25 at % Sn.

E13. The alloy according to any one of the preceding embodiments, wherein the storage secondary phase abundance is ≤ 13.3% by weight; or about 0.1-13.3, about 0.1-12, about 0.1-11, about 0.1-10, about 0.1-7 or about 0.1-5; or about 0.5, about 0.8, about 1.1, about 1.4, about 1.7, about 2.0 or about 2.3 and values therebetween, based on the alloy.

E14. The alloy according to any one of the preceding embodiments, comprising: about 2-10 wt%, about 3-9 wt%, or about 3-8 wt% of a catalytic secondary phase comprising Ti and Ni, and 0 to about 2 % by weight, about 0.01-1.5% by weight, or about 0.05-1.3% by weight of storage secondary phases containing Y and Ni, based on the total amount of the alloy.

E15. The alloy according to any one of the preceding embodiments, wherein the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≥ 4, or wherein the ratio of the abundance of the catalytic secondary phase to the abundance of the storage secondary phase The weight ratio between is about 4-10, 4 to about 9, or 4 to about 8.

E16. An alloy according to any one of the preceding embodiments, which

Contains Ti, Zr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, Ni, Mn and one or more rare earth elements; or

Contains Ti, Cr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn, Sn, Al, Cu, Mo, W, Fe, Si and Co; or

Contains Ti, Zr, V, Ni, Cr and one or more elements selected from B, Al, Si, Sn and other transition metals; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn and Al; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and Y.

E17. The alloy according to any one of the preceding embodiments, comprising about 0.1-60% Ti, about 0.1-40% Zr, 0 to about 60% V, 0 to about 56% Cr, about 5-22% Mn, about 0.1-57% of Ni, about 0.1-3% of Sn, about 0.1-10% of Al, about 0.1-11% of Co, and about 0.1-10% of one or more rare earth elements; wherein the percentages are atomic % and the total equals 100%; or

Contains about 5-15% Ti, about 18-29% Zr, about 3.0-13% V, about 1-10% Cr, about 6-18% Mn, about 29-41% Ni, about 0.1-1% Sn, about 0.1-0.7% Al, about 2-11% Co, and about 0.2-5% one or more rare earth elements, where the percentages are atomic % and the total equals 100%; or

Contains about 11-13% Ti, about 21-23% Zr, about 9-11% V, about 6-9% Cr, about 6-8% Mn, about 31-34% Ni, about 0.2-0.4% Sn, about 0.3-0.6% Al, about 2-8% Co, and about 0.2-2.0% one or more rare earth elements, where percentages are atomic % and the total equals 100%.

E18. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) C14 or C15 main Laves phase, or C14 and C15 main Laves phase,

b) about 0.1-13.3% by weight of a stored secondary phase, and

c) about 1-40% by weight of a catalytic secondary phase,

wherein the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≧3, or wherein the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

E19. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) C14 or C15 main Laves phase, or C14 and C15 main Laves phase,

b) about 0.1-13.3% by weight of a storage secondary phase comprising Y and Ni, and

c) about 1-40% by weight of a catalytic secondary phase containing Ti and Ni,

wherein the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≧3, or wherein the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

E20. The alloy according to any one of the preceding embodiments, which contains about 0.05-0.98 at % of one or more rare earth elements; or contains about 0.05-10.0 at % of one or more rare earth elements or about 0.1-7.0 at % %, about 0.2-5.0at%, or about 0.2-2.0at%, of one or more rare earth elements, based on the alloy; or wherein the alloy contains about 0.05at%, about 0.1at%, about 0.15at%, about 0.20at% %, about 0.25at%, about 0.30at%, about 0.35at%, about 0.40at%, about 0.45at%, about 0.50at%, about 0.55at%, about 0.60at%, about 0.65at%, about 0.70at% %, about 0.75at%, about 0.80at%, about 0.85at%, about 0.90at%, about 0.95at%, or about 0.98at% of one or more rare earth elements, based on the alloy, and between them value.

E21. The alloy according to any one of the preceding embodiments, which contains Y.

E22. A hydrogen storage alloy according to any one of the preceding embodiments, which exhibits an improved surface catalytic capability at -40°C relative to the AB ₂ alloy Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, or at least 40%, wherein surface catalytic capability is defined as the product of charge transfer resistance (R) and double layer capacitance (C); and / or

Charge transfer resistance at -40°C ≤60Ω·g, ≤55Ω·g, ≤50Ω·g, ≤45Ω·g, ≤40Ω·g, ≤37Ω·g, ≤35Ω·g, ≤30Ω·g, ≤ 25Ω·g, ≤20Ω·g or ≤15Ω·g; and/or

Surface catalytic ability at -40°C ≤30s, ≤25s, ≤20s, ≤15s, ≤12s, ≤10.0s, ≤9.0s, ≤8.0s, ≤7.0s, ≤6.0s or ≤ 5.0 seconds, surface catalytic ability is defined as the product of charge transfer resistance (R) and double layer capacitance (C); or surface catalytic ability at -40°C is about 5-10 seconds, about 5-9 seconds, about 5- 8 seconds or about 5-7 seconds.

The following are other embodiments of the present invention.

E1. A hydrogen storage alloy, e.g. with improved low temperature electrochemical properties, comprising at least one primary phase and at least one secondary phase, e.g.

a) at least one main phase,

b) optionally stored secondary phase, for example 0 to about 13.3% by weight stored secondary phase, and

c) a catalytic secondary phase,

wherein the alloy contains about 0.05-0.98 at % of one or more rare earth elements; or wherein the alloy contains about 0.05-10.0 at % of one or more rare earth elements or about 0.1-7.0 at %, about 0.2-5.0 at % or about 0.2-2.0 at % of one or more rare earth elements, based on the alloy; or, wherein the alloy contains about 0.05 at %, about 0.1 at %, about 0.15 at %, about 0.20 at %, about 0.25 at %, about 0.30at%, about 0.35at%, about 0.40at%, about 0.45at%, about 0.50at%, about 0.55at%, about 0.60at%, about 0.65at%, about 0.70at%, about 0.75at%, About 0.80 at%, about 0.85 at%, about 0.90 at%, about 0.95 at% or about 0.98 at% of one or more rare earth elements, based on the alloy, and values therebetween.

E2. The alloy according to embodiment 1, comprising:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metals and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements,

wherein the atomic ratio between ii) and i) is 1.80-2.20; or about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93; or about 1.80, about 1.81, about 1.82, about 1.83, about 1.84, about 1.85 , about 1.86, about 1.87, about 1.88, about 1.89, about 1.90, about 1.91, about 1.92, about 1.93, about 1.94, about 1.95, about 1.97, about 1.98 or about 1.99.

E3. The alloy according to embodiment 2, wherein the atomic ratio between ii) and i) is about 1.80-1.95.

E4. The alloy according to any one of the preceding embodiments, which contains C14 and C15 major Laves phases, wherein the weight abundance of the C14 phase is about 70-95, about 80-90, or about 83-88, and the C15 phase abundance is according to About 2-20, about 3-15, or about 3-13 by weight, based on the alloy.

E5. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase has a TiNi(B2) crystal structure.

E6. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase contains one or more elements selected from Ti, Zr, Nb and Hf, and also contains Ni.

E7. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase contains about 13-45 at % Ti, about 15-30 at % Ti, or about 15-25 at % Ti, about 5-30 at % Zr, about 15-28 at% Zr or about 20-26 at% Zr, and about 38-60 at% Ni, about 40-55 at% Ni or about 45-50 at% Ni.

E8. The alloy according to any one of the preceding embodiments, wherein the abundance of the catalytic secondary phase is ≥ 3 and ≤ 40% by weight; or the weight abundance of the catalytic secondary phase is about 1-40, about 3-20 by weight , or about 4, about 5, about 6, about 7, about 8, about 9, or about 10, based on the alloy.

E9. The alloy according to any one of the preceding embodiments, wherein the abundance of the storage secondary phase is >0% by weight; or about 0.1-12, about 0.1-11, about 0.1-10, about 0.1-7 or From about 0.1 to 5; or about 0.5, about 0.8, about 1.1, about 1.4, about 1.7, about 2.0 or about 2.3, and values therebetween, based on the alloy.

E10. The alloy according to any one of the preceding embodiments, which contains a storage secondary phase containing one or more rare earth elements; containing Ni; containing one or more rare earth elements and Ni; containing one Or a variety of rare earth elements, Ni and Sn; containing Y and Ni, or containing Y, Ni and Sn.

E11. The alloy according to any one of the preceding embodiments, which contains a storage secondary phase comprising about 15-55 at%, about 20-50 at%, about 25-45 at%, or about 30-40 at% of a one or more rare earth elements; or wherein the storage secondary phase contains about 30-50at% or about 30-40at% of one or more rare earth elements, and wherein the storage secondary phase contains about 15-50at% Ni, about 20-40 at % Ni or about 20-30 at % Ni.

E12. The alloy according to any one of the preceding embodiments, comprising a storage secondary phase comprising about 15-32 at % Sn, about 18-30 at % Sn or about 20-29 at % Sn.

E13. The alloy according to any one of the preceding embodiments, comprising a storage secondary phase comprising about 32-38 at % Y, about 21-27 at % Ni and about 20-25 at % Sn.

E14. The alloy according to any one of the preceding embodiments, comprising: about 2-10 wt%, about 3-9 wt%, or about 3-8 wt% of a catalytic secondary phase comprising Ti and Ni, and 0 to about 2 % by weight, about 0.01-1.5% by weight, or about 0.05-1.3% by weight of storage secondary phases containing Y and Ni, based on the total amount of the alloy.

E15. The alloy according to any one of the preceding embodiments, which contains a storage secondary phase, wherein the weight ratio between the catalytic secondary phase and the storage secondary phase is ≥ 3, ≥ 4, ≥ 5, ≥ 6 or ≥ 7, or wherein the weight ratio between the catalytic secondary phase and the storage secondary phase is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

E16. An alloy according to any one of the preceding embodiments, which

Contains Ti, Zr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, Ni, Mn and one or more rare earth elements; or

Contains Ti, Cr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn, Sn, Al, Cu, Mo, W, Fe, Si and Co; or

Contains Ti, Zr, V, Ni, Cr and one or more elements selected from B, Al, Si, Sn and other transition metals; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn and Al; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and Y.

E17. The alloy according to any one of the preceding embodiments, comprising about 0.1-60% Ti, about 0.1-40% Zr, 0 to about 60% V, 0 to about 56% Cr, about 5-22% Mn, about 0.1-57% of Ni, about 0.1-3% of Sn, about 0.1-10% of Al, about 0.1-11% of Co, and about 0.1-10% of one or more rare earth elements; wherein the percentages are atomic % and the total equals 100%; or

Contains about 5-15% Ti, about 18-29% Zr, about 3.0-13% V, about 1-10% Cr, about 6-18% Mn, about 29-41% Ni, about 0.1-1% Sn, about 0.1-0.7% Al, about 2-11% Co, and about 0.2-5% one or more rare earth elements, where the percentages are atomic % and the total equals 100%; or

Contains about 11-13% Ti, about 21-23% Zr, about 9-11% V, about 6-9% Cr, about 6-8% Mn, about 31-34% Ni, about 0.2-0.4% of Sn, about 0.3-0.6% of Al, about 2-8% of Co and about 0.2-2.0% of one or more rare earth elements, where the percentages are atomic % and the total equals 100%.

E18. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) at least one main phase,

b) 0 to about 13.3% by weight of storage secondary phase, and

c) a catalytic secondary phase,

The alloy contains:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metals and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements,

wherein the atomic ratio between ii) and i) is about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93.

E19. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) C14 or C15 main Laves phase, or C14 and C15 main Laves phase,

b) 0 to about 13.3% by weight of storage secondary phase, and

c) about 1-40% by weight of a catalytic secondary phase,

wherein the alloy contains about 0.05-0.98 at% Y, and

where the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≥3, ≥4, ≥5, ≥6, or ≥7, or where the abundance of the catalytic secondary phase to the abundance of the storage secondary phase The weight ratio between is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

E20. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) C14 or C15 main Laves phase, or C14 and C15 main Laves phase,

b) 0 to about 13.3% by weight of a storage secondary phase comprising Y and Ni, and

c) about 1-40% by weight of a catalytic secondary phase containing Ti and Ni,

wherein the alloy contains about 0.05-0.98 at% Y, and

where the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≥3, ≥4, ≥5, ≥6, or ≥7, or where the abundance of the catalytic secondary phase to the abundance of the storage secondary phase The weight ratio between is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

E21. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) C14 or C15 main Laves phase, or C14 and C15 main Laves phase,

b) 0 to about 13.3% by weight of storage secondary phase, and

c) about 1-40% by weight of a catalytic secondary phase,

The alloy contains:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from the group consisting of V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and Y,

wherein the atomic ratio between ii) and i) is about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93.

E22. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) C14 or C15 main Laves phase, or C14 and C15 main Laves phase,

b) 0 to about 13.3% by weight of a storage secondary phase comprising Y and Ni, and

c) about 1-40% by weight of a catalytic secondary phase containing Ti and Ni,

The alloy contains:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from the group consisting of V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and Y,

wherein the atomic ratio between ii) and i) is about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93.

E23. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) C14 or C15 main Laves phase, or C14 and C15 main Laves phase,

b) 0 to about 13.3% by weight of a storage secondary phase comprising Y and Ni, and

c) about 1-40% by weight of a catalytic secondary phase containing Ti and Ni,

Wherein the alloy contains about 0.05-0.98 at% Y,

where the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≥3, ≥4, ≥5, ≥6, or ≥7, or where the abundance of the catalytic secondary phase to the abundance of the storage secondary phase The weight ratio between is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8, and

The alloy contains:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from the group consisting of V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and Y,

wherein the atomic ratio between ii) and i) is about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93.

E24. The alloy according to any one of the preceding embodiments, which contains Y.

E25. The hydrogen storage alloy according to any one of the preceding embodiments, which exhibits an improved surface catalytic capability at -40°C relative to the AB ₂ alloy Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, or at least 40%, wherein surface catalytic capability is defined as the product of charge transfer resistance (R) and double layer capacitance (C); and / or

Charge transfer resistance at -40°C ≤60Ω·g, ≤55Ω·g, ≤50Ω·g, ≤45Ω·g, ≤40Ω·g, ≤37Ω·g, ≤35Ω·g, ≤30Ω·g, ≤ 25Ω·g, ≤20Ω·g or ≤15Ω·g; and/or

Surface catalytic ability at -40°C ≤30s, ≤25s, ≤20s, ≤15s, ≤12s, ≤10.0s, ≤9.0s, ≤8.0s, ≤7.0s, ≤6.0s or ≤ 5.0 seconds, where surface catalytic capacity is defined as the product of charge transfer resistance (R) and double layer capacitance (C); or surface catalytic capacity at -40°C is about 5-10 seconds, about 5-9 seconds, about 5 -8 seconds or about 5-7 seconds.

The following are other embodiments of the present invention.

E1. A hydrogen storage alloy showing:

Improvement of surface catalytic ability at -40°C by at least 10%, at least 15%, at least 20%, at least 25% relative to AB ₂ alloy Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 , at least 30%, at least 35% or at least 40%, wherein surface catalytic capability is defined as the product of charge transfer resistance (R) and double layer capacitance (C); and/or

Charge transfer resistance at -40°C ≤ 60, ≤ 55, ≤ 50, ≤ 45, ≤ 40, ≤ 37, ≤ 35 ≤ 30, ≤ 25, ≤ 20 or ≤ 15 Ω g; and/or

Surface catalytic ability at -40°C ≤30s, ≤25s, ≤20s, ≤15s, ≤12s, ≤10.0s, ≤9.0s, ≤8.0s, ≤7.0s, ≤6.0s or ≤ 5.0 seconds, where surface catalytic capacity is defined as the product of charge transfer resistance (R) and double layer capacitance (C); or surface catalytic capacity at -40°C is about 5-10 seconds, about 5-9 seconds, about 5 -8 seconds or about 5-7 seconds.

E2. The hydrogen storage alloy according to embodiment 1, comprising at least one primary phase and at least one secondary phase, for example

a) at least one main phase,

b) optionally stored secondary phase, for example 0 to about 13.3% by weight stored secondary phase, and

c) a catalytic secondary phase,

wherein the alloy contains 0.05-0.98 at % of one or more rare earth elements; or wherein the alloy contains about 0.05-10.0 at % of one or more rare earth elements or about 0.1-7.0 at %, about 0.2-5.0 at % or About 0.2-2.0 at % of one or more rare earth elements, based on the alloy; or wherein the alloy contains about 0.05 at %, about 0.1 at %, about 0.15 at %, about 0.20 at %, about 0.25 at %, about 0.30 at % at%, about 0.35at%, about 0.40at%, about 0.45at%, about 0.50at%, about 0.55at%, about 0.60at%, about 0.65at%, about 0.70at%, about 0.75at%, about 0.80 at%, about 0.85 at%, about 0.90 at%, about 0.95 at% or about 0.98 at% of one or more rare earth elements, based on the alloy, and values therebetween.

E3. The hydrogen storage alloy according to embodiment 1 or 2, comprising:

a) at least one main phase,

b) 0 to about 13.3% by weight of storage secondary phase, and

c) a catalytic secondary phase,

The alloy contains:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metals and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements,

wherein the atomic ratio between ii) and i) is about 1.80-2.20, about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93.

E4. The hydrogen storage alloy according to any one of the preceding embodiments, comprising:

a) at least one main phase,

b) store the secondary phase, and

c) a catalytic secondary phase,

where the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≥3, ≥4, ≥5, ≥6, or ≥7, or where the abundance of the catalytic secondary phase to the abundance of the storage secondary phase The weight ratio between is about 3-10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

E5. The alloy according to any one of the preceding embodiments, comprising:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metals and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements,

wherein the atomic ratio between ii) and i) is about 1.80-2.20.

E6. The alloy according to any one of embodiments 3-5, wherein the atomic ratio between ii) and i) is about 1.80-1.99.

E7. The alloy according to any one of embodiments 2-6, wherein the structure of each phase is different.

E8. The alloy according to any one of embodiments 2-7, which contains a C14 or C15 major Laves phase, or a C14 and a C15 major Laves phase.

E9. The alloy according to any one of embodiments 2-8, which contains C14 and C15 major Laves phases, wherein the weight abundance of the C14 phase is about 70-95, about 80-90 or about 83-88, and the C15 phase is abundant The degree is about 2-20, about 3-15, or about 3-13 by weight, based on the alloy.

E10. The alloy according to any one of embodiments 2-9, wherein the catalytic secondary phase has a TiNi(B2) crystal structure.

E11. The alloy according to any one of embodiments 2-10, wherein the catalytic secondary phase contains one or more elements selected from Ti, Zr, Nb and Hf, and also contains Ni.

E12. The alloy according to any one of embodiments 2-11, wherein the catalytic secondary phase contains Ti and Ni, or Ti, Zr and Ni.

E13. The alloy according to any one of embodiments 2-12, wherein the catalytic secondary phase contains about 13-45 at % Ti, about 15-30 at % Ti, or about 15-25 at % Ti.

E14. The alloy according to any one of embodiments 2-13, wherein the catalytic secondary phase contains about 5-30 at % Zr, about 15-28 at % Zr or about 20-26 at % Zr.

E15. The alloy according to any one of embodiments 2-14, wherein the catalytic secondary phase contains about 38-60 at % Ni, about 40-55 at % Ni, or about 45-50 at % Ni.

E16. The alloy according to any one of embodiments 2-15, wherein the catalytic secondary phase contains about 45-49 at % Ni, about 17-22 at % Ti and about 20-24 at % Zr, wherein (Ti+Zr) is About 41-43at%.

E17. The alloy according to any one of embodiments 2-16, wherein the catalytic secondary phase contains about 45-49 at % Ni, about 17-22 at % Ti and about 20-24 at % Zr, wherein (Ti+Zr) is About 41-43 at%, and wherein the at% of Zr is > at% of Ti.

E18. The alloy according to any one of embodiments 2-17, wherein the abundance of the catalytic secondary phase is ≥ 3 and ≤ 40% by weight; or the weight abundance of the catalytic secondary phase is about 1-40 by weight, About 3-20, or about 4, about 5, about 6, about 7, about 8, about 9 or about 10, based on the alloy.

E19. The alloy according to any one of embodiments 2-18, wherein the storage secondary phase contains one or more rare earth elements.

E20. The alloy according to any one of embodiments 2-19, wherein the storage secondary phase contains Ni.

E21. The alloy according to any one of embodiments 2-20, wherein the storage secondary phase contains one or more rare earth elements and Ni, or one or more rare earth elements, Ni and Sn.

E22. The alloy according to any one of embodiments 2-21, wherein the storage secondary phase contains Y and Ni, or Y, Ni and Sn.

E23. The alloy according to any one of embodiments 2-22, wherein the storage secondary phase contains about 15-55 at%, about 20-50 at%, about 25-45 at%, or about 30-40 at% of one or more rare earths The element; or storage secondary phase contains about 30-50 at % or about 30-40 at % of one or more rare earth elements.

E24. The alloy according to any one of embodiments 2-23, wherein the storage secondary phase contains about 15-50 at % Ni, about 20-40 at % Ni, or about 20-30 at % Ni.

E25. The alloy according to any one of embodiments 2-24, wherein the storage secondary phase contains about 15-32 at % Sn, about 18-30 at % Sn or about 20-29 at % Sn.

E26. The alloy according to any one of embodiments 2-25, wherein the storage secondary phase contains about 32-38 at % Y, about 21-27 at % Ni and about 20-25 at % Sn.

E27. The alloy according to any one of embodiments 2-26, wherein the storage secondary phase abundance is > 0 and ≤ 13.3% by weight, or about 0.1-10, about 0.1-7 or about 0.1-5; or by weight About 0.5, about 0.8, about 1.1, about 1.4, about 1.7, about 2.0 or about 2.3, and values in between, based on the alloy.

E28. The alloy according to any one of the preceding embodiments, comprising about 2-10 wt. %, about 3-9 wt. %, or about 3-8 wt. % of a catalytic secondary phase comprising Ti and Ni, and 0 to about 2 wt. %, about 0.01-1.5% by weight, or about 0.05-1.3% by weight of storage secondary phases containing Y and Ni, based on the total amount of the alloy.

E29. The alloy according to any one of the preceding embodiments, which contains about 0.05-10.0 at % of one or more rare earth elements, or about 0.1-7.0 at %, about 0.2-5.0 at % or about 0.2-2.0 at % of One or more rare earth elements, based on the alloy.

E30. The alloy according to any one of the preceding embodiments, which

Contains Ti, Zr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, Ni, Mn and one or more rare earth elements; or

Contains Ti, Cr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn, Sn, Al, Cu, Mo, W, Fe, Si and Co; or

Contains Ti, Zr, V, Ni, Cr and one or more elements selected from B, Al, Si, Sn and other transition metals; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn and Al; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and Y.

E31. The alloy according to any one of the preceding embodiments, which contains Y.

E32. The alloy according to any one of the preceding embodiments, which

Contains about 0.1-60% Ti, about 0.1-40% Zr, 0<V<60%, 0 to about 56% Cr, about 5-22% Mn, about 0.1-57% Ni, about 0.1 - 3% Sn, about 0.1-10% Al, about 0.1-11% Co, and about 0.1-10% one or more rare earth elements; or

Contains about 5-15% Ti, about 18-29% Zr, about 3.0-13% V, about 1-10% Cr, about 6-18% Mn, about 29-41% Ni, about 0.1-1% Sn, about 0.1-0.7% Al, about 2-11% Co, and about 0.2-5% one or more rare earth elements; or

Contains about 11-13% Ti, about 21-23% Zr, about 9-11% V, about 6-9% Cr, about 6-8% Mn, about 31-34% Ni, about 0.2-0.4% Sn, about 0.3-0.6% Al, about 2-8% Co, and about 0.2-2.0% one or more rare earth elements,

where percentages are atomic % and the total equals 100%.

The following are other embodiments of the present invention.

E1. A hydrogen storage alloy, such as a hydrogen storage alloy with improved low-temperature electrochemical performance, comprising at least one primary phase and at least one secondary phase, such as

a) at least one main phase,

b) optionally stored secondary phase, for example 0 to about 13.3% by weight stored secondary phase, and

c) a catalytic secondary phase,

The alloy contains:

i) one or more elements selected from type A elements, and

ii) one or more elements selected from B-type elements and rare earth elements;

E.g:

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metals and rare earth elements; or

i) one or more elements selected from Ti, Zr, Nb and Hf, and

ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements,

wherein the atomic ratio between ii) and i) is about 1.80-1.98, about 1.80-1.95 or about 1.82-1.93; or about 1.80, about 1.81, about 1.82, about 1.83, about 1.84, about 1.85, about 1.86, About 1.87, about 1.88, about 1.89, about 1.90, about 1.91, about 1.92, about 1.93, about 1.94, about 1.95, about 1.97 or about 1.98.

E2. The alloy according to embodiment 1, wherein the atomic ratio between ii) and i) is about 1.80-1.95.

E3. The alloy according to embodiment 1, which contains C14 and C15 major Laves phases, wherein the weight abundance of the C14 phase is about 70-95, about 80-90, or about 83-88, and the C15 phase abundance is by weight About 2-20, about 3-15, or about 3-13, based on the alloy.

E4. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase has a TiNi(B2) crystal structure.

E5. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase contains one or more elements selected from Ti, Zr, Nb and Hf, and also contains Ni.

E6. The alloy according to any one of the preceding embodiments, wherein the catalytic secondary phase contains about 13-45 at % Ti, about 15-30 at % Ti, or about 15-25 at % Ti, about 5-30 at % Zr, about 15-28 at% Zr or about 20-26 at% Zr, and about 38-60 at% Ni, about 40-55 at% Ni or about 45-50 at% Ni.

E7. The alloy according to any one of the preceding embodiments, wherein the abundance of the catalytic secondary phase is ≥ 3 and ≤ 40% by weight; or the weight abundance of the catalytic secondary phase is about 1-40, about 3-20 by weight , or about 4, about 5, about 6, about 7, about 8, about 9, or about 10, based on the alloy.

E8. The alloy according to any one of the preceding embodiments, wherein the weight abundance of the storage secondary phase is >0 and ≤13.3; or about 0.1-13.3, about 0.1-10, about 0.1-7 or about 0.1- 5; or about 0.5, about 0.8, about 1.1, about 1.4, about 1.7, about 2.0 or about 2.3, and values therebetween, based on the alloy.

E9. The alloy according to any one of the preceding embodiments, comprising a storage secondary phase comprising one or more rare earth elements and Ni, or one or more rare earth elements, Ni and Sn.

E10. The alloy according to any one of the preceding embodiments, which contains a storage secondary phase comprising about 15-55 at%, about 20-50 at%, about 25-45 at%, or about 30-40 at% of a One or more rare earth elements; or containing about 30-50at% or about 30-40at% of one or more rare earth elements, and containing about 15-50at% Ni, about 20-40at% Ni or about 20- 30at% Ni.

E11. The alloy according to any one of the preceding embodiments comprising a storage secondary phase comprising about 15-32 at % Sn, about 18-30 at % Sn or about 20-29 at % Sn.

E12. The alloy according to any one of the preceding embodiments, comprising a storage secondary phase comprising about 32-38 at % Y, about 21-27 at % Ni and about 20-28 at % Sn.

E13. The alloy according to any one of the preceding embodiments, comprising about 2-10% by weight of a catalytic secondary phase comprising Ti and Ni and about 0.01-2% by weight of a storage secondary phase comprising Y and Ni.

E14. The alloy according to any one of the preceding embodiments, wherein the weight ratio between the abundance of the catalytic secondary phase and the abundance of the storage secondary phase is ≥ 3, ≥ 4, ≥ 5, ≥ 6 or ≥ 7, or about 3 -10, about 3-9, 3 to about 8, about 4-10, 4 to about 9, or 4 to about 8.

E15. An alloy according to any one of the preceding embodiments, which

Contains Ti, Zr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, Ni, Mn and one or more rare earth elements; or

Contains Ti, Cr, V, Ni and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn, Sn, Al, Cu, Mo, W, Fe, Si and Co; or

Contains Ti, Zr, V, Ni, Cr and one or more elements selected from B, Al, Si, Sn and other transition metals; or

Contains Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from Cr, Mn and Al; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and one or more rare earth elements; or

Contains Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and Y.

E16. The alloy according to any one of the preceding embodiments, containing about 0.1-60% Ti, about 0.1-40% Zr, 0<V<60%, 0 to about 56% Cr, about 5-22% Mn, about 0.1-57% of Ni, about 0.1-3% of Sn, about 0.1-10% of Al, about 0.1-11% of Co, and about 0.1-10% of one or more rare earth elements; is atomic % and the total equals 100%.

E17. The alloy according to any one of the preceding embodiments, which contains Y.

E18. The hydrogen storage alloy according to any one of the preceding embodiments, which exhibits an improved surface catalytic capability at -40° C. relative to the AB ₂ alloy Ti _12.0 Zr _21.5 V _10.0 Cr _7.5 Mn _8.1 Ni _32.2 Sn _0.3 Al _0.4 Co _8.0 At least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, or at least 40%, the surface catalytic capability defined as the product of charge transfer resistance (R) and double layer capacitance (C) ;and / or

A charge transfer resistance at -40°C of ≤60, ≤55, ≤50, ≤45, ≤40, ≤37, ≤35, ≤30, ≤25, ≤20, or ≤15 Ω·g; and/or

Surface catalytic ability at -40°C is ≤30 seconds, ≤25 seconds, ≤20 seconds, ≤15 seconds, ≤12 seconds, ≤10.0 seconds, ≤9.0 seconds, ≤8.0 seconds, ≤7.0 seconds, ≤6.0 seconds or ≤ 5.0 seconds, the surface catalytic ability is defined as the product of charge transfer resistance (R) and double layer capacitance (C); or the surface catalytic ability at -40°C is about 5-10 seconds, about 5-9 seconds, About 5-8 seconds or about 5-7 seconds.

The following is another set of embodiments.

E1. A metal hydride battery, a solid hydrogen storage medium, an alkaline fuel cell or a metal hydride air battery, which contains the hydrogen storage alloy of any one of the foregoing embodiments (any one of the foregoing four groups of embodiment schemes) .

E2. A metal hydride battery comprising at least one anode capable of reversibly charging and releasing hydrogen, at least one cathode capable of reversible oxidation, a housing for accommodating said anode and cathode, a separator for separating cathode and anode , and an electrolyte in contact with both the anode and the cathode, wherein the anode contains a hydrogen storage alloy according to any one of the preceding four sets of embodiment embodiments.

E3. An alkaline fuel cell comprising at least one hydrogen electrode, at least one oxygen electrode and at least one gas diffusion material, wherein the hydrogen electrode comprises a hydrogen storage alloy according to any one of the preceding four sets of embodiment embodiments.

E4. A metal hydride-air battery comprising at least one air-permeable cathode, at least one anode, at least one air inlet, and an electrolyte in contact with both the anode and the cathode, wherein the anode contains according to the preceding four groups of embodiment schemes The hydrogen storage alloy of any one embodiment.

E5. Use of an alloy according to any one of the preceding four groups of embodiments for use in electrodes in metal hydride cells, fuel cells or metal hydride-air cells.

E6. Use of the alloy according to any one of the preceding four groups of embodiments as a hydrogen storage medium.

Example 1 Y modified Ti-Zr-V-Cr-Mn-Ni-Sn-Al-Co alloy

Arc melting was performed with a non-consumable tungsten electrode and a water-cooled copper disk under a continuous flow of argon. Before each experiment, a piece of sacrificial titanium was subjected to several melting/cooling cycles to reduce the residual oxygen concentration in the system. Each 12g block was remelted and tumbled for several minutes to ensure uniformity of chemical composition. The chemical composition of each sample was determined using a VarianLIBERTY 100 Inductively Coupled Plasma (ICP) system. AC impedance testing was performed using a SOLARTRON 1250 frequency response analyzer with a sine wave with an amplitude of 10 mV and a frequency of 10 mHz to 10 kHz. Prior to testing, the electrodes were subjected to a full charge/discharge cycle at C/10 rate using a SOLARTRON 1470 Cell Test galvanostat, then recharged to 100% state of charge (SOC), then discharged to 80% (SOC), and Finally cooled to -40°C. Two more cycles of AC impedance detection were repeated at room temperature and -40°C.

The following alloys were designed, where the values are in atomic %.

The designed alloys have actual atomic percentages detected by ICP as shown below.

Alloys 6-10 are examples of the invention. Alloys 0-5 are comparative examples. Comparative alloys are described in K. Young et al., Journal of Alloy and Compounds, "Electrochemical properties of _AB2 metal hydride alloys examined at -40°C" (2013), Elsevier, 580 (2013) S349-S352.

The ii)/i) ratio is the atomic ratio (V-Cr-Mn-Ni-Sn-Al-Co-Y)/(Ti-Zr).

For the preparation of Y-containing alloys, the loss of Mn due to evaporation during melting is significant, which requires higher energy to achieve bulk homogeneity.

The electrochemical detection results are shown below.

RT is room temperature. R is the charge transfer resistance (Ω·g). C is the double layer capacitance (Farad/g). R and C values were calculated from Cole-Cole plots of AC impedance detection.

It can be seen that Y-modified alloys 6-10 have significantly improved R C values at -40 °C compared to Y-modified alloys 1-5 and the unmodified alloy (alloy 0) . A lower R·C value at -40°C is desirable, for example, the R·C at -40°C of alloy 8 is improved by 81% compared with alloy 2.

In addition to the main C14 and C15 phases, two additional phases were identified with a Philips X'PERT PRO X-ray diffractometer (XRD). The abundances of C14 phase, C15 phase, storage secondary YNi phase and catalytic secondary TiNi phase are shown below (XRD, analyzed with JADE 9 software). The unit of abundance is percent by weight, based on the total amount of the alloy.

The term "nd" means "not detectable" or "below the limit of detection".

A JEOL-JSM6320F scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS) was used to study the phase distribution and corresponding composition. Although the TiNi phase generally contains more Zr than Ti, according to XRD detection, the crystal structure of the TiNi phase is the TiNi(B2) crystal structure. The aforementioned TiNi phase contains 41-43 at % (Zr+Ti), 45-49 at % Ni, 17-22 at % Ti and 20-24 at % Zr. The above YNi phase contains 32-38 at% Y, 21-27 at% Ni and 20-28 at% Sn.

Example 2 Ti-Zr-V-Cr-Mn-Ni-Sn-Al-Co alloy modified by Sc, La or mixture of rare earth metals

Example 1 was repeated, but replacing Y with Sc, La or misch metals.

Claims (20)

1. a kind of hydrogen bearing alloy, it shows：

Relative to AB₂Alloy Ti_12.0Zr_21.5V_10.0Cr_7.5Mn_8.1Ni_32.2Sn_0.3Al_0.4Co_8.0Meter, the surface catalysis at -40 DEG C Ability improves at least 10%, and the surface catalysis ability is defined as the product of charge transfer resistance (R) and double layer capacity (C)；With/ Or

The Ω g of charge transfer resistance at -40 DEG C≤60；And/or

Surface catalysis ability≤30 second at -40 DEG C, the surface catalysis ability is defined as charge transfer resistance (R) and bilayer The product of electric capacity (C).

2. a kind of hydrogen bearing alloy, it contains at least one principal phase and at least one secondary phase, wherein one or more principal phases it is total Measure and exist according to the abundance by weight higher than each secondary phase, wherein alloy contains：

I) one or more elements for being selected from Ti, Zr, Nb and Hf, and

Ii) one or more elements selected from V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth element；Or

I) one or more elements for being selected from Ti, Zr, Nb and Hf, and

Ii) Ni, Cr and one or more elements selected from B, Al, Si, Sn, other transition metal and rare earth element；Or

I) one or more elements for being selected from Ti, Zr, Nb and Hf, and

Ii) Ni, Cr and one or more elements selected from V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth element,

Wherein ii) and i) between atom ratio be about 1.80-1.98.

3. according to the alloy of claim 1 or 2, it shows：

The Ω g of charge transfer resistance at -40 DEG C≤30；And/or

Surface catalysis ability≤8.0 second at -40 DEG C.

4. according to the alloy of claim 1 or 2, it contains：

A) at least one principal phase,

B) secondary phase is stored, and

C) secondary phase is catalyzed,

It is >=3 to be wherein catalyzed the secondary weight rate mutually between the secondary phase of storage.

5. according to the hydrogen bearing alloy of claim 1 or 2, it contains：

A) at least one principal phase,

B) secondary phase is optionally stored, and

C) secondary phase is catalyzed,

Wherein alloy contains 0.05-0.98at% one or more rare earth elements, and

The total amount of wherein one or more principal phases exists according to the abundance by weight higher than each secondary phase.

6. alloy according to claim 4, it contains the main Laves phases of C14 or C15, or contains the main Laves phases of C14 and C15.

7. alloy according to claim 4, it contains the secondary phase of the catalysis with TiNi (B2) crystal structure.

8. alloy according to claim 4, wherein catalysis is secondary mutually containing one or more elements for being selected from Ti, Zr, Nb and Hf, And also contain Ni.

9. alloy according to claim 4, wherein the abundance of the secondary phase of catalysis is >=3 and≤40 weight %.

10. alloy according to claim 4, wherein storage is secondary mutually containing one or more rare earth elements and/or Ni.

11. alloy according to claim 4, wherein storage is secondary mutually containing one or more rare earth elements, Ni and Sn.

12. alloy according to claim 4, it contains is with abundance>0 and≤13.3 weight % the secondary phase of storage.

13. alloy according to claim 4, wherein the weight rate between the secondary phase abundance of catalysis and the secondary phase abundance of storage is ≥4。

14. alloy according to claim 4, its secondary phase of catalysis containing Ti and Ni comprising about 2-10 weight %, peace treaty The 0.01-1.5 weight % secondary phase of the storage containing Y and Ni.

15. according to the alloy of claim 1 or 2, it contains about 0.1-10at% one or more rare earth elements.

16. according to the alloy of claim 1 or 2, its

Contain Ti, Zr, V, Ni and one or more rare earth elements；Or

Contain Ti, Zr, Ni, Mn and one or more rare earth elements；Or

Contain Ti, Cr, V, Ni and one or more rare earth elements；Or

Containing Ti, Zr, V, Ni, one or more rare earth element and it is one or more selected from Cr, Mn, Sn, Al, Cu, Mo, W, Fe, Si and Co element；Or

Contain Ti, Zr, V, Ni, Cr and one or more elements selected from B, Al, Si, Sn and other transition metal；Or

Contain Ti, Zr, V, Ni, one or more rare earth elements and one or more elements for being selected from Cr, Mn and Al；Or

Contain Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and one or more rare earth elements；Or

Contain Ti, Zr, V, Ni, Cr, Mn, Sn, Al, Co and Y.

17. according to the alloy of claim 1 or 2, its

Ti containing about 0.1-60%, about 0.1-40% Zr, 0<V<60%, the Cr of 0 to about 56%, about 5-22% Mn, about 0.1-57% Ni, about 0.1-3% Sn, about 0.1-10% Al, about 0.1-11% Co, and about 0.1-10% one kind or A variety of rare earth elements；Or

Ti containing about 5-15%, about 18-29% Zr, about 3.0-13% V, about 1-10% Cr, about 6-18% Mn, about 29-41% Ni, about 0.1-1% Sn, about 0.1-0.7% Al, about 2-11% Co, and about 0.2-5% one kind or many Plant rare earth element；Or

Ti containing about 11-13%, about 21-23% Zr, about 9-11% V, about 6-9% Cr, about 6-8% Mn, about 31- 34% Ni, about 0.2-0.4% Sn, about 0.3-0.6% Al, about 2-8% Co, and about 0.2-2.0% one kind or many Plant rare earth element,

Wherein percentage is atom %, and total amount is equal to 100%.

18. according to the alloy of claim 1 or 2, it contains Y.

19. according to the hydrogen bearing alloy of claim 1 or 2, it is included：

A) the main Laves phases of C14 or C15, or the main Laves phases of C14 and C15,

B) the secondary phase of the about 0.1-13.3 weight % storage containing Y and Ni, and

C) the secondary phase of the about 1-40 weight % catalysis containing Ti and Ni,

The weight rate being wherein catalyzed between secondary phase abundance and the secondary phase abundance of storage is >=3.

20. a kind of metal hydride battery, solid hydrogen-storing medium, alkaline fuel cell or metal hydride air battery, it contains The hydrogen bearing alloy of with good grounds claim 1 or 2.