HK1089550B - Zinc lanthanide sulfonic acid electrolytes - Google Patents

Description

Zinc lanthanide sulfonic acid electrolytes

The present invention claims priority from U.S. provisional application serial No. 60/471654 filed on 19/5/2003.

Background

Technical Field

The present invention relates to the use of high purity metal sulfonic acids for energy storage devices, methods of making high purity metal sulfonic acid electrolytes, methods of efficiently using metal sulfonic acid solutions, and products formed using these methods and solutions. More specifically, the present invention provides a sulfonic acid solution having high cathodic efficiency for deposition process of group 2B metal such as zinc, a sulfonic acid solution providing high solubility for lanthanide ion, and a sulfonic acid solution having low concentration of low-valent sulfur compounds or high-valent sulfur compounds that are easily reduced, which may generate odor during electrolysis.

Background

Electrochemical processes are used in many large-scale stationary energy device storage applications. The grading of the energy storage device depends on the total power supply and discharge time. The power supply can range from 1 kilowatt (1kW) for metal-air type batteries to 1 gigawatt (1GW) for pumped-water type batteries. The discharge time also ranges from less than one second to more than a few hours.

Improving the reliability or power quality of an energy storage device may require a virtually Uninterruptible Power Supply (UPS). Such electrical storage processes include capacitors and superconducting magnetic energy storage devices. During the power-off period, these devices start up in a fraction of a second, ensuring uninterrupted power supply.

The storage device may also be used for a period of several seconds to several minutes when the power supply is switched from one main power supply to another.

Electrical energy storage devices may also be used to save large users the cost of power supply when the power supply is limited. Such power supply devices provide sufficient electrical energy to meet peak energy demands for a duration of minutes to hours, or provide storage of electrical power during off-peak times.

The capacity of the energy storage process and the consequent power output depend on the engineering design of the equipment, the composition of the electrolyte used by such equipment and the type of power classification required. There are several commercially available energy storage technologies, each of which has its own advantages and disadvantages. Including polysulfide bromide cells (PSB), vanadium redox cells (VRB), zinc-bromine cells (ZnBr), sodium sulfide cells (NaS), lithium ion cells, Compressed Air Energy Storage (CAES), large scale lead acid cells (LSLA), pumped water, e.c. capacitors, and flywheel technology.

There are three flow-type cells, PSB, VRB and ZnBr. PSB cells use two sodium electrolytes, sodium bromide and sodium sulfide. The cell has an oxidation-reduction potential of about 1.5 volts and an efficiency of about 75%. VRBs use two batteries, each of which contains vanadium. In one cell, V is used⁺²/V⁺³And in the other, V is used⁺⁴/V⁺⁵. The redox voltage is about 1.4 to 1.6 volts and the efficiency is slightly higher than for PSB cells, about 85%. The redox potential of the ZnBr cell is about 1.8 volts, but its efficiency is only about 75%. All of these flow-type batteries have relatively high power levels and can be used in energy management type applications that require additional electrical power over an extended period of time. The energy density of all these flow cells is low.

The NaS cell uses molten sulfur and molten sodium to produce a redox voltage of about 2 volts with an efficiency of about 88%. The main drawbacks of this type of battery are the high temperature of 300 c required to maintain the molten state of the metal, the safety concerns associated with the use of these materials, and the high production costs.

Lithium ion batteries have efficiencies approaching 100% and have higher energy densities and longer life cycles. Although useful for small-scale applications, its major drawback is its inherent high cost for large-scale use, on the order of $ 600/kilowatt-hour.

CAES plants are capable of producing gigawatts of power for long periods of time. However, CAES power plants are very expensive, taking tens of millions of dollars and years to build such a power plant. CAES power plants are location specific and may require natural gas as fuel.

Recently, the Electrochemical Design association (Electrochemical Design association) introduced a new type of energy storage device, multi-ion Redox cell (Plurion Redox Battery). This battery uses a mixed salt of zinc and cerium in methanesulfonic acid (MSA). The redox potential of such cells exceeds 2 volts. Dougherty and colleagues discussed this zinc salt and cerium salt based Energy Storage device at the electric Energy Storage Application and technology conference, 2002EESAT conference (http:// www.sandia.gov/EESAT). There is no mention in this paper of cerium ions (e.g. Ce)⁺³Or Ce⁺⁴) The composition of (1).

MSA has been used in a variety of electrochemical processes, most notably in electrodeposition (e.g., electroplating) applications. While advantageous over other organic and inorganic acids, the purity and composition of MSA (and other sulfonic acids) and metal sulfonate electrolytes must only be in a unique balance to ensure quality of metal coating and a higher electrolytic efficiency process.

The use of sulfonic acids, in particular MSA, in electrochemical products is not new. The use of alkyl sulfonic acid electrolytes in various types of electroplating is described in U.S. patent No. 2525942 to Proell, w.a. Most importantly, the recipe for Proell uses mixed alkyl sulfonic acids of unspecified purity. In U.S. patent No. 2525942, Proell describes, among others, lead, nickel, cadmium, silver and zinc. In another U.S. patent No. 2525943, Proell specifically describes the use of alkyl sulfonic acid based electrolytes in copper plating without disclosing the exact composition and purity of the plating formulation. In another publication (Proell, W.A.; dust, C.L.; Agruss, B.; Combs, E.L.; The Monthly Review of The American Electropolaters society 1947, 34, 541-9), Proell describes a preferred formulation for copper electroplating from mixed alkyl sulfonic acid based electrolytes.

Martyak and colleagues have discussed zinc deposition from MSA-based electrolytes in EP 0786539a 2. The acid electrolyte contains about 5 grams/liter to about 175 grams/liter of zinc-sulfonate. In the pH described in this application, the zinc sulfonate solution is said to operate optimally at a pH of about 2.0 or higher, preferably in the range of 3 to 5. The efficiency of zinc deposition approaches 100% even at high current densities. The additives added to the solution affect the quality of the zinc deposit. In order to reduce the roughness of the zinc surface as much as possible, it is necessary to use organic additives such as block and random copolymers of alkylene oxides.

The use of cerium in sulfonic acids is within the scope of the invention of Kreh and co-workers in US 4701245A 1, US 4670108A 1, US 4647349A 1 and US 4639298A 1. In these patents, the oxidation of organic compounds is affected by the use of homocerium compounds such as homocerium methanesulfonate and homocerium trifluoromethanesulfonate. In all cases, only Ce in the highest oxidation state is used⁺⁴The oxidation reaction can be completed by the cerium ion. Cerium (Ce)⁺³) High cerium (Ce)⁺⁴) The concentration in MSA is critical to maintaining a stable oxidizing environment. The cerium concentration discussed in US4639298 is at least 0.2M, but it does not distinguish between Ce⁺³And Ce⁺⁴. Only Ce⁺⁴The ion is necessary for the oxidation reaction to proceed in the MSA solution. The concentration of free MSA is also important to aid in dissolving the cerium compound, preferably from 1.5M to about 9.0M.

Thus, there are many problems to be overcome with a new energy storage device based on zinc and cerium salts in sulfonic acid electrolytes. The cathodic reaction of zinc ions to metallic zinc must be balanced with the oxidation reaction of ortho-cerium ions to high-cerium ions:

Zn⁺²+2e^-→Zn⁰

2Ce⁺³→2Ce⁺⁴+2e^-

for each mole of zinc ion reduction at the cathode, two moles of ceric ions are generated at the anode. Additional free acid is necessary in the process to provide electrical conduction to the redox system, thus lowering the required voltage. However, as discussed in EP 0786539, zinc precipitatesThe pH of the product is preferably above 2.0, preferably 3-5. The concentration of zinc ions should also be high to obtain a commercially acceptable deposition rate and a smooth zinc coating. Application of high free sulfonic acid concentrations above 1.5M, preferably above 3.0M, is discussed by Kreh and co-workers in US4639298 a 1. This high free sulfonic acid concentration is necessary for the dissolution of cerium, but will result in a lower pH value < 1.0 and thus influence the zinc deposition process. High free sulfonic acid concentration also affects Ce⁺³/Ce⁺⁴The dissolution ratio of (a).

It would therefore be desirable to have a new electrochemical energy storage device containing a composition based on zinc salts in sulfonic acid and lanthanide metal salts that produces high deposition efficiency for the conversion of zinc ions to metallic zinc, produces free sulfonic acid to provide sufficient conductivity to the redox cell, and yet maintains high solubility of lanthanide ions in solution to complete the redox reaction couple.

It would be particularly desirable to have a new sulfonic acid composition that would enable the effective use of metals with strong reducing power such as zinc without any deleterious effects such as odors that are often produced when sulfonic acids containing odor-producing impurities are used.

Disclosure of Invention

When using metal salts in highly pure sulfonic acids, in particular metal salts of group 2B metals such as zinc and lanthanides such as cerium, it is possible to find a new type of high energy, high efficiency electrical energy storage device. The focus of this work has focused on the unexpected superiority of using highly pure sulfonic acids with limited free acid concentration in the sulfonic acid concentration to effectively dissolve zinc ions and lanthanide ions.

The electrolyte of the present invention is characterized primarily by containing low concentrations of free sulfonic acid, < 300 g/l. The low free sulfonic acid concentration allows for high cathodic efficiency of zinc deposition, but is also sufficient for solution conduction. The low free sulfonic acid concentration also provides improved solubility of the lanthanide ion.

The electrolyte of the present invention is characterized mainly by containing a low concentration of lanthanide ions, which may precipitate from a high concentration of sulfonic acid electrolyte.

The sulfonic acid electrolyte of the present invention is also mainly characterized by containing a reduced sulfur compound in a low concentration or a sulfur compound in a high oxidation state which is easily reduced by an active metal or reduced to a low-valent sulfur compound such as sulfide (odor-causing impurity) during electrolysis, i.e., high purity. In particular, the preferred electrochemical compositions of the invention have a low concentration of dimethyldisulfide DMDS (CH)₃SSCH₃) Dimethyl sulfide DMS (CH)₃SCH₃) Dimethyl sulfone DMSO₂(CH₃SO₂CH₃) Trichloromethyl methyl sulfone TCMS (CH)₃SO₂CCl₃) Dichloromethyl methyl sulfone DCMS (CH)₃SO₂CCl₂) Methyl thiomethanesulfonate MMTS (CH)₃SO₂SCH₃) And methyl methanesulfonate MMS ((CH)₃SO₃CH₃)。

In particular, highly pure sulfonic acids preferred in the present invention have a total concentration of reduced sulfides of less than 50 mg/l, more preferably less than 10 mg/l, and still more preferably less than 5 mg/l.

The invention also includes articles of manufacture, including batteries and other energy storage devices, using the sulfonic acids of the invention.

Detailed Description

The compositions of the invention suitably contain in the sulfonic acid electrolyte a metal ion capable of electrochemical reduction to the metallic state, one or more metals in an oxidized state which are not capable of being reduced to their metallic state, a high purity free sulfonic acid, and optionally an additive which enhances the zinc deposition reaction or which enhances the conductivity of the redox cell. The metal ions are preferably added in the form of metal salts of highly pure sulfonic acids.

As discussed previously, the electrolytes of the present invention are particularly effective for depositing metal ions of 2B (group 2B of the periodic table) such as zinc ions from a sulfonic acid solution while maintaining a high concentration of lanthanide (lanthanide of the periodic table) ions. Particularly, the sulfonic acid solution of the present invention is useful in energy storage devices such as batteries.

The electrolyte of the present invention generally comprises at least one soluble 2B metal salt, preferably a zinc salt, one or more soluble lanthanide metals, preferably cerium sulfonate, a high purity acid electrolyte, optionally a buffering agent, and optionally a conducting salt. More specifically, the electrolyte composition of the present invention preferably contains a zinc salt of an alkyl or aryl sulfonic acid of high purity; highly pure lanthanide metal salts of alkyl or aryl sulfonic acids; a high purity sulfonic acid electrolyte, preferably an acidic aqueous solution such as a high purity alkyl or aryl sulfonic acid; optionally a boric acid-based buffer; the anion of the optional conducting salt, its salt, is based in part on a high purity alkyl or aryl sulfonic acid.

Metallic zinc or various zinc salts may also be in the zinc-lanthanide electrolyte. The zinc sulfonate salt may be used in the subject solution wherein the sulfonic acid of the anionic portion of the zinc salt, as well as any free sulfonic acid, is introduced in high purity as an alkyl or aryl sulfonic acid of the general formula:

wherein R, R 'and R' are the same or different and are each independently hydrogen, phenyl, Cl, F, Br, I, CF₃Or lower alkyl groups such as (CH)₂) n in the lower alkyl group, n is 1 to 7, and can be replaced by oxygen, Cl, F, Br, I, CF₃、-SO₂OH substituted or unsubstituted. Preferred alkyl sulfonic acids are methanesulfonic acid, ethanesulfonic acid and propanesulfonic acid, and preferred alkyl polysulfonic acids are methanedisulfonic acid, monochloromethanesulfonic acid, dichloromethanedisulfonic acid, 1-ethanedisulfonic acid, 2-chloro-1, 1-ethanedisulfonic acid, 1, 2-dichloro-1, 1-ethanedisulfonic acid, 1-Propanedisulfonic acid, 3-chloro-1, 1-propanedisulfonic acid, 1, 2-ethyldisulfonic acid, 1, 3-propyldisulfonic acid, trifluoromethanesulfonic acid, butanesulfonic acid, perfluorobutanesulfonic acid, pentanesulfonic acid, arylsulfonic acid being benzenesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid. A particularly preferred zinc salt is zinc methanesulfonate.

Zinc salts may suitably be present in the electrolyte compositions of the invention in a relatively wide range of concentrations. Preferably, the zinc salt is used at a concentration of about 5 to about 500 grams per liter of solution, more preferably at a concentration of about 20 to 400 grams per liter of solution, and still more preferably at a concentration of about 40 to about 300 grams per liter of solution.

Various lanthanide metal salts, such as cerium salts, can also be in the electrolyte. Lanthanide sulfonates can be used in the subject solutions wherein the sulfonic acid of the lanthanide metal salt anion moiety, as well as any free sulfonic acid, is introduced in high purity as an alkyl or aryl sulfonic acid of the general formula:

wherein R, R 'and R' are the same or different and are each independently hydrogen, phenyl, Cl, F, Br, I, CF₃Or lower alkyl radicals such as n is 1 to 7 (CH)₂) n, the lower alkyl group being optionally substituted by oxygen, Cl, F, Br, I, CF₃、-SO₂OH substituted or unsubstituted. Preferred alkyl sulfonic acids are methanesulfonic acid, ethanesulfonic acid and propanesulfonic acid, preferred alkyl polysulfonic acids are methanedisulfonic acid, -chloromethanesulfonic acid, dichloromethanedisulfonic acid, 1-ethanedisulfonic acid, 2-chloro-1, 1-ethanedisulfonic acid, 1, 2-dichloro-1, 1-ethanedisulfonic acid, 1-propanedisulfonic acid, 3-chloro-1, 1-propanedisulfonic acid, 1, 2-ethyldisulfonic acid, 1, 3-propyldisulfonic acid, trifluoromethanesulfonic acid, butanesulfonic acid, perfluorobutanesulfonic acid, pentanesulfonic acid, and aryl sulfonic acids are benzenesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid. Particularly preferred lanthanide metal salts are cerous methanesulfonate and cerous methanesulfonate.

The preferred lanthanide acid salt is a cerium sulfonate salt and is suitably present in the electrolyte of the present invention in a relatively narrow concentration range. Ce⁺³And Ce⁺⁴The individual concentrations are controlled by the concentration of free acid in the solution.

Preferably, the cerium sulfonate salt is used at a concentration of about 5 to about 800 grams per liter of solution, more preferably at a concentration of about 20 to about 600 grams per liter of solution, and still more preferably at a concentration of about 50 to about 300 grams per liter of solution.

The sulfonate ceric salt is used at a concentration of about 0.1 to about 100 grams per liter of solution, preferably about 0.5 to about 50 grams per liter of solution, and more preferably about 1 to about 25 grams per liter of solution.

The electrolyte may also contain high purity free acid to increase the conductivity of the solution. Preferred highly pure free acids have the same anion as the zinc and lanthanide salt anions, but mixtures of highly pure free acids are also within the scope of the invention. Preferred alkyl sulfonic acids are methanesulfonic acid, ethanesulfonic acid and propanesulfonic acid, preferred alkyl polysulfonic acids are methanedisulfonic acid, monochloromethanesulfonic acid, dichloromethanedisulfonic acid, 1-ethanedisulfonic acid, 2-chloro-1, 1-ethanedisulfonic acid, 1, 2-dichloro-1, 1-ethanedisulfonic acid, 1-propanedisulfonic acid, 3-chloro-1, 1-propanedisulfonic acid, 1, 2-ethyldisulfonic acid, 1, 3-propyldisulfonic acid, trifluoromethanesulfonic acid, butanesulfonic acid, perfluorobutanesulfonic acid, pentanesulfonic acid, and aryl sulfonic acids are benzenesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid. The concentration of the free acid is in the range of about 1 g/l to about 1480 g/l, preferably in the range of about 10 g/l to about 1200 g/l, and more preferably in the range of about 30 g/l to about 300 g/l. The pH of the electrolyte may vary from about 0.5 to 4, preferably from about 2 to 3.

If a buffer is used, the buffer in the electrolyte solution includes boric acid and/or tetraborate. Electrolyte solutions containing buffers perform best at low free acid concentrations of less than 300 grams per liter of free acid and produce a more even zinc coating than unbuffered electrolyte solutions. The concentration of the buffer may vary from about 0.1 g/l to saturation, preferably from about 1 g/l to about 75 g/l, and more preferably from about 5 g/l to about 50 g/l.

The conductive salt in the electrolyte solution may include an ammonium salt, if used.

The sulfonic acid electrolytes of the present invention are preferably used at or above room temperature, e.g., up to about 85 ℃. The sulfonic acid solution may be agitated during use by, for example, gas sparging, physical movement of the workpiece, impingement, or other suitable means.

Depending on the energy storage requirements, electrolysis is preferably at 0.01 to 150 amperes per square decimeter (A/dm)²) Under a current of (3).

The invention described also includes the use of direct current, pulsed current or periodic current waveforms to effectively deposit a zinc layer on a cathode substrate.

A variety of different substrates can be plated with the zinc of the present invention as described above. Substrates include, but are not limited to: carbon, steel, copper, aluminum or alloys of these metals.

The foregoing description of the invention is merely illustrative thereof, and it is to be understood that modifications and variations may be made thereto without departing from the spirit and scope of the invention as defined in the following claims.

Example 1

This example shows the effect of free methanesulfonic acid on the conductivity of solutions containing low zinc ion concentrations. Preparation of Zn (CH)₃SO₃₎₂Dissolving Zn in a solution of²⁺The concentration was constant at 32.5 grams/liter (g/l), free CH₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 65 ℃ and the conductivity recorded as millisiemens/cm is listed in the table below.

	32.5 g/l Zn0 g/l CHSOH	32.5 g/l Zn100 g/l CHSOH	32.5 g/l Zn200 g/l CHSOH	32.5 g/l Zn300 g/l CHSOH
					20℃	40.2	231	337	366
25℃	41.3	226	331	362
					30℃	41.4	220	324	355
35℃	44.1	210	316	350
					40℃	46.2	214	308	342
45℃	49.9	201	302	338
					50℃	54.6	194.8	296	330
55℃	60.1	190	291	323
					60℃	65.2	185.1	287	313
65℃	70.2	180.5	282	308

The data show that for zinc ion solutions containing no free acid, the conductivity increases with increasing temperature, but for solutions containing 100-300 g/l free acid, the conductivity decreases with increasing temperature. The conductivity increased with increasing free acid to 300 g/l. The magnitude of the increase in conductivity was large when the free acid concentration increased from 0 to 100 g/l and from 100 g/l to 200 g/l, but there appeared to be a drop-back in the magnitude of the increase in conductivity when the free acid concentration increased from 200 g/l to 300 g/l. Thus, the zinc acid electrolyte can be operated at free acid concentrations of 200 grams/liter or less without significant adverse effects on conductivity.

Example 2

This example shows the effect of methanesulfonic acid concentration on the cathode efficiency of zinc deposition in a solution without lanthanide metals.

	32.5 g/l Zn0 g/L CHSOH	32.5 g/l ZnPer 100 g/l CHSOH	32.5 g/l Zn/200 g/l CHSOH	32.5 g/l Zn300 g/l CHSOH
					Initial weight	8.3981	8.2876	8.4798	8.3211
Final weight	8.4874	8.3781	8.5452	8.3702
					Cathode efficiency (30 ampere/square decimeter)	87.91％	89.09％	64.38％	48.34％
Appearance of the product	Light gray	Light gray	Light gray	Light gray
					Voltage of battery	2.42	1.21	0.96	0.84
Initial weight	8.4533	8.1982	8.2135	8.4224
					Final weight	8.6323	8.3891	8.3581	8.5577
Cathode efficiency (60 ampere/square decimeter)	88.11％	93.97％	71.18％	66.60％
					Appearance of the product	Light gray	Light gray	Light gray	Light gray
Voltage of battery	4.41	2.25	1.7	1.61

Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration is constant at 32.5 g/l, free CH₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 55 ℃ and zinc was deposited on mild steel at 30 amps/cm and 60 amps/cm. The data in the table above show that the cathode efficiency is higher and commercially viable at free acid concentrations of 0 and 100 g/liter, but the cathode efficiency drops slightly at a free acid concentration of 200 g/liter, and much less at a free methane sulfonic acid concentration of 300 g/liter.

Example 3

This example shows the effect of free methanesulfonic acid on the conductivity of solutions containing high concentrations of zinc ions. Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration was constant at 32.5 grams/liter (g/l), free CH₃SO₃The H concentration ranges from 0 to 500 g/l. Each solution was heated to 65 ℃ and the conductivity, recorded as millisiemens/cm, is reported in the table below.

	32.5 g/l Zn0 g/l CHSOH	32.5 g/l Zn100 g/l CHSOH	32.5 g/l Zn200 g/l CHSOH	32.5 g/l Zn300 g/l CHSOH	32.5 g/l Zn400 g/l CHSOH	32.5 g/l Zn500 g/l CHSOH
							20℃	55.6	163.5	224	219	209	150.2
25℃	62.7	179.2	240	234	210	151.1
							30℃	69.7	199.3	260	256	210	159
35℃	76.7	212	281	278	214	158.3
							40℃	83.7	227	305	302	218	158.1
45℃	91	244	327	323	224	158.7
							50℃	96.4	260	348	346	229	158.6
55℃	106.2	276	366	374	235	158.4
							60℃	113.1	291	387	391	239	157.9
65℃	119.4	302	406	409	243	157.8

The data show that for each electrolyte having a free MSA concentration below 400 g/l, the conductivity increases with increasing temperature, the conductivity increases with increasing free acid concentration to 300 g/l, the conductivity decreases as the free acid concentration continues to increase, the free acid concentration changes from 0 to 100 g/l, and the conductivity changes by a greater amount than the free acid concentration changes from 100 to 200 g/l or from 200 to 300 g/l. Thus, the zinc acid electrolyte can be operated at a free acid concentration of 300 grams/liter or less without significant adverse effects on conductivity.

Example 4

This example shows the effect of methanesulfonic acid concentration on the cathode efficiency of zinc deposition in solutions containing high concentrations of free zinc ions.

Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration was constant at 65 g/l (g/l) free CH₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 65 ℃ and zinc was deposited on mild steel at 30 amps/cm and 60 amps/cm. The data in the table below show that the cathode efficiency is high and commercially viable at free acid concentrations of 0 and 100 grams/liter, but the cathode efficiency drops significantly at free methane sulfonic acid concentrations of 200 and 300 grams/liter.

	65 g/l Zn0 g/L CHSOH	65 g/l ZnPer 100 g/l CHSOH	65 g/l Zn/200 g/l CHSOH	65 g/l Zn300 g/l CHSOH
					Initial weight	8.4916	8.4557	8.5237	8.192
Final weight	8.5882	8.5509	8.5705	8.2044
					Cathode efficiency (30 ampere/square decimeter)	95.10％	93.72％	46.07％	8.55％
Appearance of the product	Light gray	Light gray	Light gray	Light gray
					Voltage of battery	2.35	1.06	0.73	0.73
Initial weight	8.3091	8.3626	8.2063	8.4544
					Final weight	8.5077	8.5555	8.348	8.4926
Cathode efficiency (60 ampere/square decimeter)	97.76％	94.45％	69.75％	37.61％
					Appearance of the product	Light gray	Light gray	Light gray	Light gray
Voltage of battery	4.22	2.05	1.57	1.52

Example 5

This example shows the effect of boric acid concentration and free methanesulfonic acid concentration on the conductivity of a solution containing zinc ions. Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration was constant at 65 g/l (g/l) free CH₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 65 ℃ and the conductivity recorded as millisiemens/cm is listed in the table below.

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+0 g/l HBO	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+0 g/l HBO	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+0 g/l HBO	65 g/l Zn300 g/l CHSOH +70 g/l Ce+0 g/l HBO
					20℃	81.2	141.4	156	135.1
25℃	90.6	158.2	169.9	150.8
					30℃	97.4	168.5	190.5	165.8
35℃	108.6	183.5	204	182.2
					40℃	116.1	198.2	221	201
45℃	127.6	214	238	216
					50℃	135.4	228	257	234
55℃	147.8	242	274	253
					60℃	155.1	257	293	271
65℃	163.1	271	307	288

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+10 g/l HBO	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+10 g/l HBO	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+10 g/l HBO	65 g/l Zn300 g/l CHSOH +70 g/l Ce+10 g/l HBO
					20℃	78.4	130.1	142.4	123.2
25℃	86.5	142.1	155.2	134.5
					30℃	95.6	156.4	171.3	148.8
35℃	105.3	170.2	188.5	167.5
					40℃	114.6	186.4	201	188.2
45℃	123.1	201	222	201
					50℃	131.2	216	242	219
55℃	143.5	232	258	237
					60℃	153.9	248	271	259
65℃	165.1	262	287	274

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+25 g/l HBO	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+25 g/l HBO	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+25 g/l HBO	65 g/l Zn300 g/l CHSOH +70 g/l Ce+25 g/l HBO
					20℃	79.2	121.5	133.4	113.6
25℃	85.6	131.3	143.2	121.2
					30℃	92.7	145.1	154.6	132.5
35℃	101.2	152.5	171.8	149.2
					40℃	110.7	172.1	187.4	163.2
45℃	119.3	180.2	202	177.2
					50℃	128.5	196.4	217	193.2
55℃	137.8	214	238	211
					60℃	148.1	234	270	234
65℃	158.6	251	284	255

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+50 g/l HBO	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+50 g/l HBO	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+50 g/l HBO	65 g/l Zn300 g/l CHSOH +70 g/l Ce+50 g/l HBO
					20℃	74.2	110.3	114.1	98.4
25℃	81.2	120.7	120.2	107.1
					30℃	88.7	132.3	135.1	119.4
35℃	95.8	145.1	147.1	133.7
					40℃	104.2	156.5	161.6	145.5
45℃	111.9	167.2	173.9	157.1
					50℃	120.8	179.8	189.3	169.1
55℃	130.1	193.8	205	183.1
					60℃	138.1	214	226	201
65℃	147.9	223	242	220

Boric acid has little effect on conductivity, especially at lower boric acid concentrations.

Example 6

This example shows the effect of boric acid concentration and free methanesulfonic acid concentration on the anion efficiency of zinc deposition in solutions containing high concentrations of free zinc ions.

Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration is constant at 65 g/l, 20 g/l boric acid and free CH are added₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 65 ℃ and zinc was deposited on mild steel at 30 amps/cm and 60 amps/cm. The data in the table below show that the cathode efficiency is still relatively high even at a free methane sulphonic acid concentration of 300 g/l.

	65 g/l Zn0 g/L CHSOH	65 g/l ZnPer 100 g/l CHSOH/20 g/l HBO	65 g/l Zn/200 g/l CHSOH/20 g/l HBO	65 g/l Zn300 g/l CHSOH/20 g/l HBO
					Initial weight	8.6218	8.4511	8.3278	8.4332
Final weight	8.7221	8.5513	8.4133	8.5171
					Cathode efficiency (30 ampere/square decimeter)	98.74％	98.64％	84.17％	82.60％
Appearance of the product	Light gray	Light gray	Light gray	Light gray
					Voltage of battery	2.38	1.24	1.01	0.9
Initial weight	8.5532	8.4611	8.3298	8.5475
					Final weight	8.7351	8.6512	8.5131	8.7181
Cathode efficiency (60 ampere/square decimeter)	89.54％	93.57％	90.23％	83.97％
					Appearance of the product	Light gray	Light gray	Light gray	Light gray
Voltage of battery	4.25	2.22	1.7	1.64

Example 7

This example shows the effect of lithium triflate concentration and free methanesulfonic acid concentration on the conductivity of a solution containing zinc ions. Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration was constant at 65 g/l (g/l) free CH₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 65 ℃ and the conductivity recorded as millisiemens/cm is listed in the table below.

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+14 g/l Ce+0 g/l LiCFSO	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+14 g/l Ce+0 g/l LiCFSO	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+14 g/l Ce+0 g/l LiCFSO	65 g/l Zn300 g/l CHSOH +70 g/l Ce+14 g/l Ce+0 g/l LiCFSO
					20℃	83.7	140.2	159.2	138.8
25℃	91.7	156.2	176.6	156.5
					30℃	101.4	171.4	194.1	174.5
35℃	110.9	190	216	188.1
					40℃	120.2	203	230	205
45℃	129.6	218	250	225
					50℃	139.8	235	270	240
55℃	149	250	285	258
					60℃	159.2	264	304	277
65℃	170	278	319	295

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+14 g/l Ce+10 g/l LiCFSO	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+14 g/l Ce+10 g/l LiCFSO	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+14 g/l Ce+10 g/l LiCFSO	65 g/l Zn300 g/l CHSOH +70 g/l Ce+14 g/l Ce+10 g/l LiCFSO
					20℃	76.2	135	140.2	135.4
25℃	84.7	149.3	152.4	148.9
					30℃	94	165.2	170.2	161.1
35℃	104.2	179.8	183.5	179.4
					40℃	112.2	195.8	199.7	196.1
45℃	121.6	212	219	214
					50℃	131.1	228	238	233
55℃	140.5	244	259	253
					60℃	151	258	275	270
65℃	162.2	275	295	287

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+14 g/l Ce+25 g/l LiCFSO	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+14 g/l Ce+25 g/l LiCFSO	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+14 g/l Ce+25 g/l LiCFSO	65 g/l Zn300 g/l CHSOH +70 g/l Ce+14 g/l Ce+25 g/l LiCFSO
					20℃	76.2	129.2	138.1	129.4
25℃	84.2	141.2	152.3	142.2
					30℃	91.1	156.6	165	158.3
35℃	101.1	174.2	181	173
					40℃	109.8	189.2	197.5	191.3
45℃	119.7	194.5	215	208
					50℃	129.7	216	232	225
55℃	138.9	232	250	241
					60℃	149.8	249	273	259
65℃	160.2	263	287	275

	65 g/l Zn/0NCHSOH +70 g/l Ce+14 g/l Ce+50 g/l LiCFSO	65 g/l Zn/1NCHSOH +70 g/l Ce+14 g/l Ce+50 g/l LiCFSO	65 g/l Zn/2NCHSOH +70 g/l Ce+14 g/l Ce+50 g/l LiCFSO	65 g/l Zn/3NCHSOH +70 g/l Ce+14 g/l Ce+50 g/l LiCFSO
					20℃	73.2	116.3	129.2	112.4
25℃	82.2	129.2	145.4	124
					30℃	90.6	141.2	162.1	131
35℃	105.3	154.6	181.2	154.2
					40℃	109.2	169.8	196	171.2
45℃	120.8	185.4	211	187
					50℃	130.7	201	227	202
55℃	140.4	216	244	218
					60℃	151.8	233	260	236
65℃	160.8	248	275	254

Lithium triflate has little effect on conductivity, especially at lower concentrations.

Example 8

This example shows the concentration of free methanesulfonic acid versus Ce⁺³The effect of cathode efficiency of zinc deposition in the presence of ions.

Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration is constant at 65 grams per liter (g/l), Ce⁺³Concentration 70 g/l (added as mesylate), free CH₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 65 ℃ and zinc was deposited on mild steel at 30 amps/cm and 60 amps/cm. The data in the table below show that the cathode efficiency is higher and commercially viable at free acid concentrations of 0 and 100 grams/liter and higher current densities, but the cathode efficiency drops significantly at free methane sulfonic acid concentrations of 200 and 300 grams/liter.

	65 g/l Zn/ONCHSOH +70 g/l Ce	65 g/l Zn/1NCHSOH +70 g/l Ce	65 g/l Zn/2NCHSOH +70 g/l Ce	65 g/l Zn/3NCHSOH +70 g/l Ce
					Initial weight	8.293	8.7048	8.6407	8.6837
Final weight	8.3877	8.7702	8.6967	8.6971
					Cathode efficiency (30 ampere/square decimeter)	93.23％	64.38％	55.13％	26.38％
Appearance of the product	Light gray	Light gray	Light gray	Light gray
					Voltage of battery	1.74	1.26	0.71	0.83
Initial weight	8.5111	8.0504	8.435	8.1435
					Final weight	8.7113	8.2337	8.5739	8.1937
Cathode efficiency (60 ampere/square decimeter)	98.54％	90.23％	68.37％	49.42％
					Appearance of the product	Light gray	Light gray	Light gray	Light gray
Voltage of battery	3.26	2.24	1.76	2.28

Example 9

This example shows the concentration of free methanesulfonic acid versus Ce⁺³And Ce⁺⁴The effect of cathode efficiency of zinc deposition in the presence of ions.

Preparation of Zn (CH)₃SO₃)₂Dissolving Zn in a solution of²⁺The concentration is constant at 65 grams per liter (g/l), Ce⁺³Has a concentration of 70 g/l, Ce⁺⁴In the form of the mesylate salt, free CH, at a concentration of 0.1M₃SO₃The H concentration ranges from 0 to 300 g/l. Each solution was heated to 65 ℃ and zinc was deposited on mild steel at 30 amps/cm and 60 amps/cm. The data in the table below show that the cathode efficiency is higher and commercially viable at free acid concentrations of 0 and 100 grams/liter and low or high current densities, but the cathode efficiency drops much at free methane sulfonic acid concentrations of 200 and 300 grams/liter.

	65 g/l Zn0 g/L CHSOH +70 g/l Ce+14 g/l Ce	65 g/l ZnPer 100 g/l CHSOH +70 g/l Ce+14 g/l Ce	65 g/l Zn/200 g/l CHSOH +70 g/l Ce+14 g/l Ce	65 g/l Zn300 g/l CHSOH +70 g/l Ce+14 g/l Ce
					Initial weight	8.7301	8.6603	8.1086	8.3527
Final weight	8.8215	8.7471	8.1695	8.3627
					Cathode efficiency (30 ampere/square decimeter)	89.98％	85.45％	59.95％	19.69％
Appearance of the product	Light gray	Light gray	Light gray	Light gray
					Voltage of battery	1.73	1.42	1.23	1.68
Initial weight	8.0713	8.1279	8.5645	8.5081
					Final weight	8.2684	8.3174	8.6992	8.55
Cathode efficiency (60 ampere/square decimeter)	97.02％	93.28％	66.30％	41.25％
					Appearance of the product	Light gray	Light gray	Light gray	Light gray
Voltage of battery	3.57	2.88	2.21	2.7

Example 10

This example shows the effect of the solubility of a cerium salt in various concentrations of methanesulfonic acid. Containing 65 g/l Zn⁺²And 70 g/l Ce⁺³The aqueous solution of (a) was prepared with the corresponding mesylate salt. Ceric methanesulfonate was added stepwise and allowed to dissolve for at least 24 hours. The appearance of a yellow precipitate indicates Ce⁺⁴Saturation begins.

	Free CHSOH: 100 g/l	Free CHSOH: 200 gPer liter	Free CHSOH: 300 g/l
				All dissolved Ce(g/l)	54.79	20.87	4.06
All dissolved Ce(M)	0.391	0.149	0.029

When the concentration of free MSA increases, Ce⁺⁴The solubility of (a) decreases. In order to minimize the precipitation of high cerium ions in energy storage devices and possible clogging of membranes, separators and porous electrodes, it is recommended to use lower free MSA and Ce⁺⁴The Zn-Ce cell was run at concentration.

Example 11

This example shows the effect of the solubility of a cerium salt in low concentrations of methanesulfonic acid. Containing 65 g/l Zn⁺²And 70 g/l Ce⁺³The aqueous solution of (a) was prepared with the corresponding mesylate salt. Ceric methanesulfonate was added stepwise and allowed to dissolve for at least 24 hours. The appearance of a yellow precipitate indicates Ce⁺⁴Saturation begins.

	Free CHSOH: 25 g/l	Free CHSOH: 50 g/l	Free CHSOH: 75 g/l
				All dissolved Ce(g/l)	59.97	55.21	50.16
All dissolved Ce(M)	0.428	0.394	0.358

Example 12

This example shows the effect of trace impurities on the odor generated during dissolution of the active metal. Metallic Zn was dissolved in purified 70% MSA until a zinc ion concentration of 65 g/l was reached. During the decomposition of the metallic zinc, no odour was detected. Metal zinc was also dissolved in 70% MMTS (CH) containing 10 mg/L methylmethanesulfonate₃SO₂SCH₃) In the MSA of (1). During the dissolution process, an irritating odor was detected.

Claims (30)

1. An aqueous solution for an electrochemical energy storage device comprising (a) a sulfonic acid with a total concentration of less than 50 mg/l of lower valent sulfur compounds or higher valent sulfur compounds that are readily reducible, (b) one or more metals in an oxidation state that can be reduced to the zero valent oxidation state, (c) a metal in an oxidation state that cannot be reduced to its metallic state, and optionally (d) a buffer and optionally (e) a conductive salt.

2. The solution of claim 1 wherein the sulfonic acid is derived from an alkyl monosulfonic acid, an alkyl polysulfonic acid, an aryl mono or polysulfonic acid, or mixtures thereof.

3. The solution of claim 1, wherein the sulfonic acid is introduced in the general formula:

wherein R, R 'and R' are the same or different and are each independently hydrogen, phenyl, Cl, F, Br, I, CF₃Or unsubstituted or substituted by oxygen, Cl, F, Br, I, CF₃、-SO₂OH-substituted lower alkyl (CH)₂) n, wherein n is 1 to 7.

4. The solution of claim 1, wherein the sulfonic acid is methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, methanedisulfonic acid, monochloromethanesulfonic acid, dichloromethanedisulfonic acid, 1-ethanedisulfonic acid, 2-chloro-1, 1-ethanedisulfonic acid, 1, 2-dichloro-1, 1-ethanedisulfonic acid, 1-propanedisulfonic acid, 3-chloro-1, 1-propanedisulfonic acid, 1, 2-ethyldisulfonic acid, 1, 3-propyldisulfonic acid, trifluoromethanesulfonic acid, butanesulfonic acid, perfluorobutanesulfonic acid, pentanesulfonic acid, benzenesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid, and xylenesulfonic acid, or a mixture thereof.

5. The solution of claim 1, wherein the concentration of the sulfonic acid is from 1 gram to 1480 grams per liter of solution.

6. The solution of claim 1, wherein the concentration of the sulfonic acid is from 10 grams to 1200 grams per liter of solution.

7. The solution of claim 1, wherein the concentration of the sulfonic acid is from 30 grams to 300 grams per liter of solution.

8. The solution of claim 1, wherein the pH is between 0.5 and 4.

9. The solution of claim 1, wherein the sulfonic acid is a mixture of sulfonic acids.

10. The solution of claim 1 wherein the metal is introduced in the form of a metal salt of an alkyl or aryl sulfonic acid of the general formula:

wherein R, R 'and R' are the same or different and are each independently hydrogen, phenyl, Cl, F, Br, I, CF₃Or unsubstituted or substituted by oxygen, Cl, F, Br, I, CF₃、-SO₂OH-substituted lower alkyl (CH)₂) n, where n is 1 to 7, x varies from 1 to 4, and M is a metal of group 2B or of the lanthanide series of the periodic Table of the elements.

11. The solution of claim 10, wherein the metal salt alone is used at a concentration of 1 to 500 grams per liter of solution.

12. The solution of claim 10, wherein the metal salt alone is used at a concentration of 10 to 400 grams per liter of solution.

13. The solution of claim 10, wherein the metal salt alone is used at a concentration of 30 to 150 grams per liter of solution.

14. The solution of claim 10, wherein the sulfonate salt is methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, trifluoromethanesulfonic acid, or a mixture thereof.

15. The solution of claim 10, wherein the metal sulfonate is zinc methanesulfonate.

16. The solution of claim 10, wherein the metal sulfonate is cerous methanesulfonate.

17. The solution of claim 10, wherein the metal sulfonate is ceric mesylate.

18. The solution of claim 10, wherein the metal alkanesulfonate is vanadium methanesulfonate.

19. The solution of claim 1, wherein the buffer is added to adjust the pH of the solution.

20. The solution of claim 19, wherein the buffer is boric acid.

21. The solution of claim 1, wherein the conductive salt is an ammonium salt.

22. The solution of claim 1, wherein the concentration of low valent sulfur compounds or high valent sulfur compounds that are susceptible to reduction is less than 50 grams per liter of the solution.

23. A method of depositing a metal from the solution of claim 1 comprising electroplating the metal or metal alloy onto a substrate by passing an electric current through the solution.

24. The method of claim 23, wherein the substrate is an inert electrode of steel, copper or copper alloy, nickel or nickel alloy, cobalt or cobalt alloy, refractory metal or oxide thereof, carbon, or organic substrate.

25. The method of claim 23, wherein the sulfonic acid is methanesulfonic acid.

26. The method of claim 23, wherein the solution contains a mixture of sulfonic acids and other inorganic and organic acids.

27. The method of claim 23, wherein direct current, pulsed current, or periodic reverse current is used.

28. The method of claim 23, wherein soluble, insoluble or inert electrodes are used.

29. The method of claim 23, wherein the temperature of the solution is between 20 ℃ and 95 ℃.

30. The method of claim 23, wherein the metal is a pure metal or a metal alloy with a metal from group 2B and the lanthanide series of the periodic table of elements or a combination thereof.