CN1151570C - A secondary lithium battery with a carbon material deposited on the surface of a nano-alloy as a negative electrode - Google Patents

Abstract

The present invention belongs to the technical field of room temperature secondary lithium batteries. The present invention provides a secondary lithium battery, which is composed of a positive electrode, a negative electrode, an organic electrolyte solution or a polymer electrolyte, wherein the negative electrode is made of a carbon material with nano alloy deposited on the surface, the carbon material in the composite material serves as a rigid skeleton, and the nano alloy is dispersed and pinned on the surface of the carbon material. The secondary lithium battery of the present invention has the advantages of high capacity, good cyclicity, safety and reliability, resistance to large current charging and discharging, and environmental friendliness. The secondary lithium battery of the present invention is suitable for various occasions such as mobile phones and laptop computers.

Description

A secondary lithium battery with a carbon material deposited on the surface of a nano-alloy as a negative electrode

technical field

The invention belongs to the technical field of high-energy batteries, in particular to the technical field of room-temperature secondary lithium batteries.

Background technique

Among the negative electrode active materials of the secondary lithium battery, the theoretical specific capacity of metal lithium is 3830mAh/g, so the energy density of the secondary lithium battery using metal lithium as the negative electrode active material is the highest. However, dendrite growth occurs in the lithium metal negative electrode during charging and discharging, which causes the internal short circuit of the battery, causing the battery to burn or even explode. In order to improve its safety, from the early 1970s to the end of the 1980s, lithium alloys such as lithium aluminum, lithium silicon, lithium lead, lithium tin, lithium cadmium, etc. had replaced metal lithium as the negative electrode active material, although this was avoided to a certain extent. However, these alloys will gradually pulverize due to volume expansion and contraction during repeated charge and discharge, that is, dimensionally unstable. Causes the electrical contact between the alloy particles and the current collector and between the alloy particles to deteriorate, resulting in deterioration of battery performance or even failure, such as reference [1]: Abraham, Electrochemical Communication, Volume 138, Page 1233, 1993 (K.M. Abraham, Electrochemical. Acta, Vol. 138, 1233 (1993)).

In 1980, Armand proposed that the secondary lithium battery could use a "rocking chair" battery system (later also known as "lithium-ion" battery), that is, both positive and negative active materials use intercalation compounds. Capable of reversibly storing and exchanging lithium ions, thereby avoiding the use of metallic lithium or lithium alloys. Intercalation compounds such as LiWO ₂ and Li ₆ Fe ₂ O ₃ were initially used as negative electrode active materials, but their energy density was too low. After ten years of hard work, in March 1989, Japan's SONY company applied for a patent for a secondary lithium battery that uses carbon as the negative electrode active material and LiCoO ₂ as the positive electrode active material, and first commercialized it in 1992, as documented [ 2] Scrosati, Journal of the Electrochemical Society, Vol. 139, p. 2776, 1992 (Bruno Scrosati, J. Electrochem. Soc, Vol. 139, 2776 (1992)).

Since then, secondary lithium batteries have developed rapidly. Various forms of carbon materials such as petroleum coke, carbon fiber, pyrolytic carbon, natural graphite, artificial graphite, etc. are widely selected as negative electrode active materials for secondary lithium batteries.

However, the specific capacity of graphite-based carbon materials as negative electrode active materials is lower than 372mAh/g, which still cannot satisfy people's further pursuit of high energy density secondary batteries.

Recently, our laboratory and some other research groups have proposed the use of ultrafine active/inactive composite alloy systems as negative electrode active materials. The absolute volume change of each particle of the ultrafine alloy is small during the charging and discharging process, and the special microstructure of the composite material helps to reduce the volume change. Therefore, compared with larger size alloy materials, its cycle performance is significantly improved. Such as literature:

[3] Yang Jun, Winter, Besenhard, Solid State Ionics, Volume 90, Page 281, 1996 (J.Yang, M.Winter, J.O.Besenhard, Solid State Ionics, 90, 281(1996))

[4] Mao Ou, Dunlap, Courtney, Dunn, Journal of the Electrochemical Society, Volume 145, Page 4195, 1998 (O.Mao, R.A.punlap, I.A.Courtney, J.R. Dahm, J.Electrochem.Soc., 145, 4195 (1998)

[5] Li Hong, Huang Xuejie, Chen Liquan, Liang Yong, Wu Zhengang, Journal of Electrochem. -State Lett., 2, 547(1999))

[6] Li Hong, Huang Xuejie, Chen Liquan, A secondary lithium battery with nano-phase metal material as the anode active material, CN 97112460.4

[7] Li Hong, Huang Xuejie, Chen Liquan, a secondary lithium battery, CN 98117759.X

However, further studies have shown that due to the large surface energy of the ultrafine alloy anode material, it will gradually agglomerate during the charging and discharging process to form particles with a size of up to microns, resulting in poor long-term cycle performance and loss of kinetic advantages, such as References [8] Li Hong, Huang Xuejie, Chen Liquan, Solid State Ionics, 2000, published (H.Li, X.J.Huang, L. Q.Chen, SolidState Ionics, 2000, in press).

Contents of the invention

The object of the present invention is to provide a secondary lithium battery using a carbon material deposited on the surface of a nano-alloy as a negative electrode. In this composite, the carbon material provides a rigid backbone that does not agglomerate during charging and discharging. At the same time, the nano-alloys are scattered and pinned on the surface of the carbon material and cannot be in contact with each other. The electrode material with this special structure can effectively reduce the agglomeration of the nano-alloys during the charging and discharging process. Since both carbon materials and nano-alloy materials are active materials, this composite material has a high charge and discharge capacity, and at the same time has good cycle characteristics and safety. Moreover, this composite material also has obvious advantages in kinetics. The secondary lithium battery using the above-mentioned negative electrode has significant advantages such as high capacity, good cycle performance, safety and reliability, high current charge and discharge resistance, cheap electrode materials, easy preparation and environmental friendliness.

The main components of the secondary lithium battery of the present invention include a carbon negative electrode deposited on the surface of a nano-alloy, a lithium-containing transition metal oxide positive electrode, an organic electrolyte solution or a polymer electrolyte. Wherein, the positive electrode and the negative electrode are separated by a diaphragm soaked in an organic electrolyte solution or a polymer electrolyte, and one end of the positive electrode and the negative electrode are respectively welded on the current collector to connect with the two ends of the mutually insulated battery case.

The carbon negative electrode with nano-alloy deposited on the surface of the present invention has the following characteristics. The carbon material is used as the core skeleton structure, and its average particle size is 1 μm to 100 μm. The nanometer-sized alloy is distributed on the surface of the carbon material, and its average particle size is 5nm to 200nm. The weight percentage of nano alloy and carbon material is from 10% to 70%. Among them, carbon materials refer to carbon that can reversibly insert and extract lithium, mainly including mesocarbon pellets, coke, natural graphite, artificial graphite, pyrolytic carbon and carbon fibers, and other carbon materials with electrochemical capacity.

In the surface-deposited nano-alloy carbon material in the present invention, the surface-deposited nano-alloy can be a single metal that can form an alloy with lithium, or an alloy that can react with lithium or a multi-phase mixed alloy. Elemental substances include Sb, Sn, In, Zn, Bi. In the alloy or multi-phase mixed alloy composition, at least one of the five elements of Sb, Sn, In, Zn, and Bi is contained. Since Sb, Sn, In, Zn, and Bi can still react reversibly with lithium after adding other elements to the alloy, it is allowed to add other metal elements in the periodic table to the alloy or multi-phase mixed alloy, but Sb, Sn, The sum of the moles of In, Zn and Bi in the alloy is not less than 50%. Since the nano-metal or alloy is relatively active, its surface will inevitably be oxidized during the preparation process. Therefore, in the nano-alloy, a small amount of oxygen is allowed, but the ratio of O element to the sum of the moles of all other metal elements Not higher than 10%. For example, metal Sb, SnSb alloy, Sn _0.88 Sb _0.12 [its actual composition may be a two-phase mixture of Sn _0.76 and (SnSb) _0.12 , or a two-phase mixture of Sn _0.88 and Sb _0.12 ], Sn _0.44 Sb _0.16 Cu _0.4 , Sn _0.4 Zn _0.55 O _0.05 all meet the above requirements. However, expressions such as Sn _0.35 Cu _0.65 , Sn _0.15 Sb _0.15 Ni _0.55 O _0.15 are beyond the definition of this patent application.

The carbon negative electrode with surface-deposited nano-alloys mentioned in the present invention means that the surface-deposited means that the particles of nano-alloys are basically dispersed on the surface of the carbon particles. The dissociated nano-alloy not on the surface of the carbon particle accounts for no more than 50% of the total mass of the nano-alloy.

The preparation method of the negative electrode in the present invention is: uniformly mixing the carbon material deposited on the surface of the nano-alloy and the conductive additive, and then uniformly mixing with the binder at normal temperature and pressure to form a composite material slurry. Among them, the conductive additives refer to substances commonly used in lithium-ion batteries to increase the conductivity of active materials, such as carbon black, acetylene black, graphite powder, metal powder, and metal wire. Its weight percentage with active substance is 0% to 15%. Binders include solutions or emulsions. For example, an emulsion formed by mixing polytetrafluoroethylene with water, and a solution formed by dissolving polyvinylidene fluoride in cyclohexane. The aforementioned composite material slurry is evenly coated on various conductive foils, nets, porous bodies, fiber materials as current collectors, such as copper foil, nickel mesh, nickel foam, carbon felt and other carriers. The thickness of the obtained film is about 20-150 μm, then dry the film at 100°C-150°C, press it tightly at a pressure of 20Kg/ ^cm2 , and continue to bake at 100°C-150°C for 12 hours, according to the specifications of the prepared battery Cutting into various shapes is the negative electrode.

The positive electrode active material of the secondary lithium battery of the present invention is a known material for the positive electrode of the secondary lithium battery, that is, a lithium-containing transition metal oxide that can reversibly intercalate and extract lithium, typically such as lithium cobalt oxide, Lithium nickel oxide, lithium manganese oxide, etc.

The organic electrolyte solution of the secondary lithium battery of the present invention is a common electrolyte solution for secondary lithium batteries, which can be composed of one organic solvent or a mixed solvent composed of several organic solvents plus one or several soluble lithium salts. Typical organic solvents such as ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, dimethoxyethane, etc. Typical soluble lithium salts such as perchloric acid Lithium, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium trifluoromethanesulfonate, lithium hexafluoroarsenate, etc. A typical system such as 1 mole of lithium hexafluorophosphate is dissolved in ethylene carbonate and diethyl carbonate with a volume ratio of 1:1, and 1 mole of lithium hexafluorophosphate is dissolved in a medium of ethylene carbonate and dimethyl carbonate with a volume ratio of 3:7. . The polymer electrolyte of the present invention is a common polymer electrolyte for secondary lithium batteries, such as polyethylene containing lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium trifluoromethanesulfonate, lithium hexafluoroarsenate, etc. PEO (poly-ethylene oxide), polypropylene oxide PPO (poly-propylene oxide), polyacrylonitrile PAN (poly-acrylonitrile), PMMA (poly-methyl methacrylate), polyvinyl chloride PVC (poly-vinyl chloride) , polyvinylidene fluoride PVDF (poly-vinylidene fluoride), etc.

The diaphragm of the secondary lithium battery of the present invention is a common diaphragm for secondary lithium batteries, such as a porous polypropylene diaphragm, a porous polyethylene diaphragm, and the like.

The secondary lithium battery of the present invention has high reversible capacity, good cycle performance, safety and reliability, high current charge and discharge resistance, low electrode material, easy preparation and environmental friendliness. The secondary lithium battery of the present invention is suitable for various occasions, such as mobile phones, notebook computers, portable video recorders, electronic toys and other occasions that require mobile power sources, especially for occasions that require higher energy density and higher power density. Such as cordless power tools, electric vehicles or hybrid vehicles and other fields.

The present invention also provides a method for preparing carbon materials deposited on the surface of nano-alloys. The present invention will be further described below in conjunction with charts and typical examples.

Description of drawings

Fig. 1 is a schematic structural view of other materials of the button-type experimental battery of the present invention.

Fig. 2 is an X-ray diffraction pattern diagram of mesophase carbon spheres (MCMB28) with nano SnSb alloy deposited on the surface in Example 2 of the present invention.

Fig. 3 is a scanning electron micrograph of MCMB28 deposited on the surface of nano-SnSb alloy in Example 2 of the present invention.

4 is a simulated battery charge and discharge curve in Example 2 of the present invention using MCMB28 deposited on the surface of nano-SnSb alloy as the active material of the working electrode.

Fig. 5 is a charge-discharge curve of a simulated battery using needle coke deposited on the surface of nano-SnSb alloy as the active material of the working electrode in Example 9 of the present invention.

Table 1 is a table of charge and discharge data of the experimental batteries of Examples 1-21 and Comparative Examples of the present invention.

Wherein: 1, stainless steel sealing nut, 2, polytetrafluoroethylene nut, 3, stainless steel spring sheet, 4, take the carbon material of surface deposition nano-alloy as the working electrode of active material, 5, porous polypropylene diaphragm Celgard ^® 2300 ( Soaked in the electrolyte), 6, the lithium metal counter electrode, 7, the measuring wire.

Detailed ways

Example 1

In order to study the electrochemical performance of the carbon material deposited on the surface of the nano-alloy of the present invention as the negative electrode active material of the secondary lithium battery, an experimental battery is used for research. The structure of the experimental battery is shown in Figure 1. Wherein 1 is a stainless steel sealing nut, 2 is a polytetrafluoroethylene nut, 3 is a stainless steel spring sheet, 4 is a working electrode with the carbon material of nanometer metal or alloy deposited on the surface as the active material, and 5 is a porous polypropylene diaphragm ^Celgard® 2300 (soaked in the electrolyte), 6 is the metal lithium sheet counter electrode, and 7 is the measuring wire. The electrolyte is a mixed solvent of 1 mole of lithium hexafluorophosphate (LiPF ₆ ) dissolved in ethylene carbonate (EC) and diethyl carbonate (DEC) Medium (1:1 volume ratio).

The preparation method of the active material of the working electrode in this embodiment is described as follows: SbCl ₃ and SnCl ₂ .H ₂ O were mixed at a molar ratio of 1:1 and then dissolved in ethylene glycol to form a 0.5M solution. Then, MCMB2800 (mesophase carbon pellets, graphitized at 2800C) with an average particle size of 10 μm was added to the above solution at a weight percentage ratio of 9.2:1 (carbon:alloy) and stirred evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature was controlled at 20°C. Finally, the black precipitate was filtered, washed with ethanol, and vacuum dried to obtain a carbon composite material sample with nano SnSb alloy deposited on the surface. After drying, the nano alloy accounted for 10% by weight of the composite material. The average particle size of the SnSb alloy observed by the scanning electron microscope is 60nm, and the free SnSb alloy accounts for less than 5% of the total alloy. The obtained product has an oxygen content of less than 4% through elemental analysis.

The preparation method of the working electrode with the carbon composite material of the nano SnSb alloy deposited on the surface as the active material is described as follows: the above-mentioned composite carbon powder, the carbon black as the conductive additive and the N-methylpyrrolidone solution of polyvinylidene fluoride as the binding agent The slurry is mixed under normal temperature and pressure to form a slurry, and evenly coated on the copper foil substrate as a current collector, and the thickness of the obtained film is about 100 μm. After the obtained film was dried at 150°C, it was pressed at 20Kg/cm ² and then dried at 150°C for 12 hours. Composite carbon powder after drying, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and then the film is cut into a circular sheet with an area of ^1cm2 as the composite carbon negative electrode of nano-SnSb alloy deposited on the surface, and the number is CNMA1.

A metal lithium sheet with a thickness of 0.4mm and an area of ^1cm2 was used as the positive electrode.

All the battery materials in Figure 1, except the electrolyte, were dried and assembled into an experimental battery as shown in Figure 1 in an argon-filled glove box.

The experimental battery is subjected to a charge-discharge cycle test by an automatic charge-discharge instrument controlled by a computer. The current density is 0.1mA/cm ² , the charge cut-off voltage is 2.0V, and the discharge cut-off voltage is 0.05V. The charging and discharging data are listed in Table 1. The reversible capacity values in Table 1 are calculated based on the negative active material, that is, the second-week discharge capacity divided by the mass of the negative active material. The first number in the cycle parameter indicates the charge and discharge efficiency in the first week, that is, the charge capacity in the first week divided by the discharge capacity in the first week. The second number represents the cycle, which is the charge capacity of the tenth week divided by the charge capacity of the first week.

Example 2

According to the synthesis method described in Example 1, it is 30% carbon composite material that the nano-alloy accounts for the weight percentage of the composite material, and the average grain size of the SnSb alloy observed by scanning electron microscope is 80nm, and the ratio of the free SnSb alloy accounted for the whole alloy is lower than 15%. The obtained product has an oxygen content of less than 2% through elemental analysis. The X-ray diffraction pattern of the composite material is shown in Figure 2, and its scanning electron microscope picture is shown in Figure 3. Its structure and morphology are typical of such carbon/nanoalloys.

The composite carbon powder in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride are mixed at normal temperature and pressure to form a slurry, which is evenly coated on the copper foil substrate, and the thickness of the obtained film is about 100 μm. After drying the composite carbon powder, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA2.

Other materials, structure, assembly and testing methods of the experimental battery are the same as in Example 1. The charge and discharge data are listed in Table 1, and the charge and discharge curves are shown in FIG. 4 . This charge-discharge curve is a typical charge-discharge curve of graphite-like carbon deposited on the surface of nanometer SnSb alloy.

Example 3

According to the synthesis method described in Example 1, the control reaction temperature is 130°C, and the carbon composite material in which the nano-alloy accounts for 70% by weight of the composite material is prepared, wherein the average grain size of the SnSb alloy observed by a scanning electron microscope is 200nm, and the free SnSb Alloy accounts for less than 10% of the total alloy. The obtained product has an oxygen content of less than 1% through elemental analysis.

The composite carbon powder in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride are mixed at normal temperature and pressure to form a slurry, which is evenly coated on the copper foil substrate, and the thickness of the obtained film is about 100 μm. After drying the composite carbon powder, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA3.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 4

According to the synthesis method similar to that described in Example 1, SbCl ₃ and SnCl ₂ were prepared. H ₂ O was mixed at a molar ratio of 1:1 and then dissolved in glycerol to form a 0.05M solution. Then MCMB2800 (mesophase carbon pellets, graphitized at 2800° C.) with an average particle size of 1 μm was added to the above solution at a weight percentage ratio of 9.2:1 (carbon:alloy) and stirred evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, the carbon composite material sample with nano-SnSb alloy deposited on the surface is obtained. After drying, the nano-alloy accounts for 10% by weight of the composite material, and the average particle size of the SnSb alloy observed by scanning electron microscope is 5nm, the free SnSb alloy accounts for less than 5% of the total alloy. The obtained product has an oxygen content of less than 10% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying the composite carbon powder, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA4.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 5

According to the synthesis method described in Example 1, it is 40% composite carbon material that nano-alloy accounts for the weight percent of composite material, and the average particle size of SnSb alloy observed by scanning electron microscope is 100nm, and the ratio of free SnSb alloy to all alloys is lower than 10%. The obtained product has an oxygen content of less than 2% through elemental analysis. With the composite carbon material in this example, the N-methylpyrrolidone solution of carbon black and polyvinylidene fluoride is mixed at normal temperature and pressure to form a slurry, which is evenly coated on the copper foil substrate, and the thickness of the obtained film is about 100 ( m. Composite carbon powder after drying, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the preparation steps of the rest of the working electrode are the same as in Example 1. The number of the working electrode is CNMA5.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 6

According to the synthesis method described in Example 1, the composite carbon material that the nano-alloy accounts for the weight percentage of the composite material is 35% is prepared, and the average particle size of the SnSb alloy observed by scanning electron microscopy is 10nm, and the ratio of the free SnSb alloy to the whole alloy is lower than 10%. The obtained product has an oxygen content of less than 5% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying the composite carbon powder, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA6.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 7

Similar to the synthesis method described in Example 1, except that MCMB2800 is replaced by GPCF28 (graphitized pitch-based carbon fiber at 2800°C, with an average diameter of 10 μm, a length of 60-300 μm, and an average of 100 μm), the nano-alloy accounts for the weight of the composite material For the composite carbon material with a percentage of 30%, the average particle size of the SnSb alloy observed by scanning electron microscopy is 60nm, and the free SnSb alloy accounts for as little as 25% of the total alloy. The obtained product has an oxygen content of less than 2% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA7.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 8

Similar to the synthesis method described in Example 1, except that MCMB2800 was replaced by NG911 (natural graphite, with an average particle size of 38 μm), a composite carbon material in which the nano-alloy accounted for 40% by weight of the composite material was obtained. The average particle size of the SnSb alloy observed by the scanning electron microscope is 100nm, and the free SnSb alloy accounts for less than 50% of the total alloy. The obtained product has an oxygen content of less than 1% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA8.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 9

Similar to the synthetic method described in Example 1, just change MCMB2800 into Coke 1200 (1200 ℃ of processing pitch coke, average particle size is 60 μ m) wherein, obtain the composite carbon material that nano-alloy accounts for 35% by weight of composite material, The average particle size of the SnSb alloy observed by the scanning electron microscope is 90nm, and the free SnSb alloy accounts for less than 10% of the total alloy. The obtained product has an oxygen content of less than 1% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA9.

Other materials, structure, assembly and testing methods of the experimental battery are the same as in Example 1. The charge and discharge curve is shown in Figure 5, which is a typical charge and discharge curve of SnSb alloy deposited on the carbon surface with a low degree of graphitization. The charging and discharging data are listed in Table 1.

Example 10

Similar to the synthesis method described in Example 1, except that MCMB2800 is replaced by PS900 (900 ° C, Ar atmosphere pyrolysis sucrose, the average particle size is 10 μm), and the nano-alloy accounts for 40% by weight of the composite carbon material , the average particle size of SnSb alloy observed by scanning electron microscope is 60nm, and the proportion of free SnSb alloy in the whole alloy is lower than 15%. The obtained product has an oxygen content of less than 2% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA10.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 11

Similar to the synthetic method described in Example 1, just change MCMB2800 into PCG28 (artificial coated graphite, average grain size is 10 μm) wherein, obtain the composite carbon material that nano-alloy accounts for 30% by weight of composite material, scanning electron microscope It is observed that the average particle size of the SnSb alloy is 50nm, and the free SnSb alloy accounts for less than 10% of the total alloy. The obtained product has an oxygen content of less than 3% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA11.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 12

The preparation method of the working electrode active material is described as follows: _SbCl3 was dissolved in glycerol to form a 0.5 M solution, and then MCMB2800 (mesophase carbon pellets, graphitized at 2800 °C) with an average particle size of 10 μm was added to the above solution Stir well. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, the carbon composite material sample with nano-Sb metal deposited on the surface is obtained. After drying, the nano-alloy in the composite carbon powder accounts for 30% by weight of the composite material. The average particle size is 80nm, and the free Sb accounts for less than 10% of the total Sb. The obtained product has an oxygen content of less than 1% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride are mixed at normal temperature and pressure to form a slurry, which is evenly coated on the sub-copper foil substrate, and the thickness of the obtained film is about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA12.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 13

The preparation method of the working electrode active material is described as follows: SnCl ₂ .H ₂ O was dissolved in glycerol ethylene glycol to form a 0.1M solution. Then add MCMB2800 with an average particle size of 25 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, the carbon composite material sample with nano-Sn metal deposited on the surface is obtained. After drying, the nano-alloy in the composite carbon powder accounts for 50% by weight of the composite material. The average particle size is 150nm, and the free Sn accounts for less than 5% of the total Sn. The obtained product has an oxygen content of less than 1% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA13.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 14

The preparation method of the working electrode active material is described as follows: SbCl ₃ and InCl ₃ are mixed in a molar ratio of 1:1 and then dissolved in ethylene glycol to form a 0.5M solution. Then add MCMB2800 with an average particle size of 25 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, the carbon composite material sample with nano-InSb metal deposited on the surface is obtained. After drying, the nano-alloy in the composite carbon powder accounts for 30% by weight of the composite material. The average particle size is 60nm, and the free InSb accounts for less than 5% of the total InSb. The obtained product has an oxygen content of less than 1% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA14.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 15

The preparation method of the working electrode active material is described as follows: _SbCl3 was dissolved in ethylene glycol to form a 0.5 M solution. Then add MCMB2800 with an average particle size of 25 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 150%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, a carbon composite material sample of nano-SbZn/Sb alloy [the molar ratio of Sb and Zn is 2:1] is obtained. After drying, the nano-alloy accounts for The weight percentage of the composite material is 40%, the average particle size of the SbZn/Sb alloy observed by scanning electron microscope is 80nm, and the free SbZn/Sb alloy accounts for less than 5% of the whole SbZn/Sb alloy. The obtained product has an oxygen content of less than 4% through elemental analysis.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA15.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 16

The preparation method of the working electrode active material is described as follows: _ZnCl2 was dissolved in glycerol to form a 0.05 M solution. Then add MCMB2800 with an average particle size of 25 μm into the above solution and stir evenly. Slowly add Mg powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, the carbon composite material sample with nano-metal Zn deposited on the surface is obtained. After drying, the nano-alloy in the composite carbon powder accounts for 30% by weight of the composite material. The average particle size is 150nm, and the free Zn accounts for less than 5% of the total Zn. The chemical formula of the product was determined by elemental analysis to be Zn _0.9 Mg _0.0 7O _0.03 .

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA16.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 17

The preparation method of the working electrode active material is described as follows: SnCl ₂ . H ₂ O and CuCl ₂ were mixed at a molar ratio of 1:1 and then dissolved in ethylene glycol to form a 0.5M solution. Then add Coke 1200 with an average particle size of 60 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing Coke 1200 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate was cleaned with ethanol after filtration, and after vacuum drying, a carbon composite material sample with nano-Cu ₆ Sn ₅ alloy deposited on the surface was obtained. After drying, the nano-alloy in the composite carbon powder accounted for 30% by weight of the composite material. Scanning electron microscope The average particle size of the observed nano-alloy is 80nm, and the proportion of free nano-alloys to all nano-alloys is less than 5%. The chemical formula of the product was determined by elemental analysis to be Cu _0.4 Sn _0.33 Zn _0.20 O _0.07 .

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA17.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 18

The preparation method of the working electrode active material is described as follows: SnCl ₂ .H ₂ O and SbCl ₃ were mixed in a molar ratio of 2:3 and then dissolved in ethylene glycol to form a 0.5M solution. Then add MCMB2800 with an average particle size of 25 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, a carbon composite material sample with nano metal or alloy deposited on the surface is obtained. After drying, the nano alloy in the composite carbon powder accounts for 35% by weight of the composite material. The average particle size of the alloy is 80nm, and the dissociated nano-alloy accounts for less than 5% of the total nano-alloy. The chemical formula of the product was determined by elemental analysis to be Sn _0.35 Sb _0.65 Zn _0.88 O _0.02 .

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA18.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 19

The preparation method of the working electrode active material is described as follows: _InCl3 was dissolved in glycerol to form a 0.1 M solution. Then add MCMB2800 with an average particle size of 25 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, a carbon composite material sample with nano-In metal deposited on the surface is obtained. After drying, the nano-alloy in the composite carbon powder accounts for 50% by weight of the composite material. The nano-In metal was observed by scanning electron microscopy. The average particle size of the metal is 80nm, and the proportion of free nano-In metals to all nano-In metals is less than 5%. The oxygen content of the product was measured to be less than 1%.

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA19.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 20

The preparation method of the working electrode active material is described as follows: SnCl ₂ .H ₂ O and FeCl ₃ are mixed in a molar ratio of 2:1 and then dissolved in ethylene glycol to form a 0.5M solution. Then add Coke 1200 with an average particle size of 60 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate is cleaned with ethanol after filtration, and after vacuum drying, the carbon composite material sample of the surface deposited nano Sn/SnFe alloy is obtained. After drying, the nano alloy accounts for 30% by weight of the composite material in the composite carbon powder, and the scanning electron microscope observation The average particle size of the nanometer Sn/SnFe alloy is 100nm, and the proportion of the free nanometer Sn/SnFe alloy in the whole nanometer Sn/SnFe alloy is lower than 5%. The chemical formula of the product was determined by elemental analysis to be Sn _0.7 Fe _0.25 O _0.05 .

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA20.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Example 21

The preparation method of the working electrode active material is described as follows: _BiCl3 was dissolved in ethylene glycol to form a 0.5 M solution. Then add MCMB2800 with an average particle size of 25 μm into the above solution and stir evenly. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature is controlled at 0-3°C. Finally, the black precipitate was filtered and cleaned with ethanol, and after vacuum drying, the carbon composite material sample with nano-Bi metal deposited on the surface was obtained. After drying, the nano-metal Bi in the composite carbon powder accounted for 30% by weight of the composite material. The average particle size of metal Bi is 100nm, and the proportion of free nano metal Bi to all nano metal Bi is lower than 5%. The chemical formula of the product was determined by elemental analysis to be Bi _0.98 O _0.02 .

The composite carbon material in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying, the carbon powder is composited, and the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is CNMA21.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

[comparative embodiment one]

Similar to the synthesis method described in Example 1, SbCl ₃ and SnCl ₂ .H ₂ O were mixed at a molar ratio of 1:1 and dissolved in ethylene glycol to form a 0.5M solution. Slowly add Zn powder into the solution containing MCMB2800 at a metering ratio of 95%, while stirring at a high speed. The reaction temperature was controlled at 0°C. Finally, the black precipitate was filtered, washed with ethanol, and vacuum-dried to obtain a nano-SnSb alloy sample. The average particle size of the SnSb alloy observed by the scanning electron microscope is 70nm, and the oxygen content of the obtained product is lower than 2% through elemental analysis.

The nano-SnSb alloy in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying the nano-SnSb alloy, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is SnSb.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

[comparative embodiment two]

Similar to the synthesis method described in Example 1, SbCl ₃ was dissolved in glycerol to form a 0.5M solution. Slowly add Zn powder into the solution at a metering ratio of 95%, while stirring at a high speed. The reaction temperature was controlled at 0°C. Finally, the black precipitate was filtered, washed with ethanol, and vacuum-dried to obtain a nano-Sb metal sample. The average particle size of the nanometer Sb metal observed by the scanning electron microscope is 100nm, and the oxygen content of the obtained product is lower than 2% through elemental analysis.

The nano-Sb metal in this example, carbon black and N-methylpyrrolidone solution of polyvinylidene fluoride were mixed at normal temperature and pressure to form a slurry, which was uniformly coated on a copper foil substrate, and the thickness of the obtained film was about 100 μm. After drying the nano-Sb metal, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is Sb.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

[comparative embodiment three]

Mix MCMB2800, carbon black and polyvinylidene fluoride in N-methylpyrrolidone solution at normal temperature and pressure to form a slurry, and evenly coat it on a copper foil substrate. The thickness of the obtained film is about 100 μm. After drying MCMB2800, the weight percentage of carbon black and polyvinylidene fluoride is 90:5:5, and the rest of the working electrode preparation steps are the same as in Example 1. The working electrode number is MCMB.

Other materials, structures, assembly and testing methods of the experimental battery are the same as in Example 1, and the charging and discharging data are listed in Table 1.

Table 1: The number of the working electrode whose active material is the carbon material deposited on the surface of nanometer metal or alloy Components and proportions of carbon materials deposited on the surface of nano-metals or alloys Electrochemical properties of the corresponding simulated battery Corresponding example number Carbon material as skeleton in composite materials Metals or alloys in composites Adhesion alloy accounts for the proportion of all alloys The weight percent of the alloy in the material Reversible Capacity (mAh/g) Cyclic parameters (%) type Average particle size (μm) Composition expression after elemental analysis Average particle size (nm) CNMA1 MCMB28 10 Sn _0.48 Sb _0.48 O _0.04 60 95 10 330 88,99 1 CNMA2 MCMB28 6 Sn _0.48 Sb _0.50 O _0.02 80 85 30 420 84, 98 2 CNMA3 MCMB28 10 Sn _0.48 Sb _0.50 O _0.01 200 90 70 668 70, 92 3 CNMA4 MCMB28 1 Sn _0.48 Sb _0.47 O _0.1 5 95 25 431 85, 99 4 CNMA5 MCMB28 10 Sn _0.48 Sb _0.50 O _0.02 100 90 40 510 73, 96 5 CNMA6 MCMB28 10 Sn _0.47 Sb _0.48 O _0.05 10 90 35 484 74, 94 6 CNMA7 GPCF28 100(L), 10(D) Sn _0.38 Sb _0.6 O _0.02 60 75 30 437 72,88 7 CNMA8 NG911 38 Sn _0.3 Sb _0.69 O _0.01 100 50 40 482 76, 94 8 CNMA9 Coke 1200 60 Sn _0.48 Sb _0.51 O _0.01 90 90 35 366 76, 98 9 CNMA10 PS 900 10 Sn _0.49 Sb _0.49 O _0.02 60 85 40 610 70, 91 10 CNMA11 PCG28 10 Sn _0.485 Sb _0.485 O _0.03 50 90 30 458 75, 95 11 CNMA12 MCMB28 10 Sb _0.99 O _0.01 80 90 70 552 65, 85 12 CNMA13 MCMB28 25 Sn _0.99 O _0.01 150 95 50 647 90, 85 13 CNMA14 MCMB28 25 In _0.495 Sb _0.495 O _0.01 60 95 30 414 82,87 14 CNMA15 MCMB28 25 Sb _0.64 Zn _0.32 O _0.04 80 95 40 422 78,90 15 CNMA16 MCMB28 25 Zn _0.9 Mg _0.07 O _0.03 150 95 30 327 78,85 16 CNMA17 Coke 1200 60 Cu _0.4 Sn _0.33 Zn _0.20 O _0.07 80 95 30 277 70, 80 17 CNMA18 MCMB28 25 Sn _0.35 Sb _0.65 Zn _0.08 O _0.02 80 95 35 454 78,95 18 CNMA19 MCMB28 25 In _0.99 O _0.01 100 95 50 500 70, 88 19 CNMA20 MCMB28 25 Sn _0.7 Fe _0.25 O _0.05 80 95 30 680 72, 85 20 CNMA21 MCMB28 25 Bi _0.99 O _0.01 100 90 30 330 85, 95 twenty one SnSb / / Sn _0.49 Sb _0.49 O _0.02 70 / / 720 70, 85 than 1 Sb / / Sb _0.99 O _0.02 100 / / 620 65, 75 than 2 MCMB MCMB28 10 / / / / 320 92,99 than 3

Claims (4)

1, a kind of material with carbon element with surface deposition nano metal or alloy is the serondary lithium battery of negative pole, comprise negative pole, the transition metal oxide positive pole that contains lithium, organic electrolyte solution or polymer dielectric, separate by barrier film that has soaked organic electrolyte solution or polymer dielectric between positive pole and the negative pole, positive pole is burn-on respectively to go between on collector with an end of negative pole and is linked to each other with the battery case two ends of mutually insulated, and it is characterized in that: used negative pole is that the material with carbon element of surface deposition nano metal or alloy is made;

Wherein material with carbon element is a core skeleton, and its average particle size particle size is 25 μ m to 100 μ m;

Nano metal or alloy mainly are distributed in the surface of material with carbon element, and its particle mean size is that 5nm is to 200nm;

The percentage by weight of nano metal or alloy and material with carbon element from 10% to 70%;

Described surface deposition nano metal or alloy are elemental metals or alloy, and elemental metals comprises Sb, Sn, In, Zn, Bi; In the composition of alloy, contain Sb at least, Sn, In, Zn, five kinds of elements of Bi a kind of, and Sb, Sn, In, Zn, five kinds of elements of Bi shared molal quantity sum in alloy is not less than 50%.

2, be the serondary lithium battery of negative pole by the described material with carbon element with surface deposition nano metal or alloy of claim 1, it is characterized in that: described material with carbon element is mesocarbon bead, coke, native graphite, Delanium, RESEARCH OF PYROCARBON or carbon fiber.

3, by being the serondary lithium battery of negative pole by the described material with carbon element of claim 1 with surface deposition nano metal or alloy, it is characterized in that: add a small amount of oxygen in nano metal that can also be therein or the alloy, but the ratio of all metallic element molal quantity sums of oxygen element and other is not higher than 10%.

4, by being the serondary lithium battery of negative pole by the described material with carbon element with surface deposition nano metal or alloy of claim 1, it is characterized in that: wherein the ratio that accounts for nano metal or alloy gross mass of free nano metal or the alloy on the carbon granule surface is not higher than 50%.

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