Composite negative material for lithium ion battery and manufacture method of composite negative material

A technology for lithium ion batteries and composite materials, applied in the field of composite negative electrode materials and their preparation, can solve the problems of low initial charge and discharge efficiency, easy deposition of metallic lithium, and large volume changes.

Active Publication Date: 2015-05-27
CHINA AUTOMOTIVE BATTERY RES INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, carbon materials have the following disadvantages: 1. React with the electrolyte to form an SEI film, resulting in low initial charge and discharge efficiency; 2. Metal lithium is easy to deposit on the surface of the negative electrode, and there is no obvious voltage indication at the end of charging, which is easy to cause Safety issues; 3. Poor compatibility with electrolytes, such as co-intercalation of PC-containing electrolytes in graphite-like carbon materials; 4. Large volume changes during charging and discharging, and unsatisfactory cycle stability
[0004] The preparation methods of lithium titanate generally include traditional high-temperature solid-phase method, sol-gel method, etc. The traditional high-temperature solid-phase method is based on TiO 2 with Li 2 CO 3 Or LiOH is synthesized at a high temperature of 800 ° C to 1000 ° C as a raw material, and the reaction time is generally 12 to 24 hours. The advantage of this method is that the process is simple and it is easy to produce on a large scale. The sol-gel method generally uses the organic alkoxide of titanium and lithium as the precursor, and the target product is prepared by hydrolysis and sol-gel process. Compared with the traditional high-temperature solid-phase method, the product has high chemical purity, good uniformity, and relatively small particles. Fine, etc., and the operation is complicated, not suitable for large-scale production

Method used

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  • Composite negative material for lithium ion battery and manufacture method of composite negative material
  • Composite negative material for lithium ion battery and manufacture method of composite negative material
  • Composite negative material for lithium ion battery and manufacture method of composite negative material

Examples

Experimental program
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Effect test

Embodiment 1

[0077] Take vinyl-terminated polymethylphenylsiloxane (C 2 h 3 ) 3 SiO{CH 3 (C 6 h 5 )SiO} n Si(C 2 h 3 ) 3 n is 150, puts into the aluminum oxide crucible, adds acetone and dilutes, the volume of added acetone is 3 times of the polymethylphenylsiloxane volume of vinyl termination, then sucrose and comparative example 1Li 4 Ti 5 o 12 Add it, according to C / SiCO / Li 4 Ti 5 o 11.66 f 0.34 C and SiCO account for SiCO and Li respectively 4 Ti 5 o 12 2wt% and 5wt% of the total weight were added with sucrose and vinyl-terminated polymethylphenylsiloxane, wherein the amounts of sucrose and vinyl-terminated polymethylphenylsiloxane were according to the same experimental conditions for sucrose and ethylene The pyrolysis rate of group-terminated polymethylphenylsiloxane was calculated. After the addition, heat to 400° C. while stirring, and keep for 5 hours. After the polysiloxane is cured, a precursor is formed. Put the crucible containing the precursor into the high...

Embodiment 2

[0080] Hydroxyl-terminated polymethylphenylsiloxane (OH) 3 SiO{CH 3 (C 6 h 5 )SiO} n Si(OH) 3 n is 50, puts into the aluminum oxide crucible, adds acetone and dilutes, the volume of added acetone is 4 times of the polymethylphenylsiloxane volume of hydroxy-terminated, then glucose and the Li of comparative example 2 4 Ti 5 o 11.66 f 0.34 Add it, according to C / SiCO / Li 4 Ti 5 o 11.66 f 0.34 Middle C accounts for SiCO and Li 4 Ti 5 o 11.66 f 0.34 5 wt% of the total weight was added to glucose, SiCO accounted for SiCO and Li 4 Ti 5 o 12 7.5wt% of the total weight was added with hydroxyl-terminated polymethylphenylsiloxane, wherein the amount of glucose and hydroxyl-terminated polymethylphenylsiloxane was according to the same experimental conditions for glucose and hydroxyl-terminated polymethylphenylsiloxane. The pyrolysis rate of phenylsiloxane was calculated. Heat to 300° C. while stirring, and keep for 1 hour, and the precursor is formed after the polysilox...

Embodiment 3

[0082] Hydroxyl-terminated polymethylethoxysiloxane (OH) 3 SiO{CH 3 (OC 2 h 5 )SiO} n Si(OH) 3 n is 150, puts into alumina crucible, adds toluene to dissolve, and the volume of added toluene is 1.5 times of the polymethylethoxysiloxane volume of hydroxy-terminated, then starch and the Li of comparative example 3 4 Ti 4.8 mn 0.2 o 11.66 f 0.34 Add it, according to C / SiCO / Li 4 Ti 4.8 mn 0.2 o 11.66 f 0.34In C, 5wt% of the total weight is added to starch, SiCO is added to 3wt% of the total weight, and hydroxyl-terminated polymethylethoxysiloxane is added, wherein the addition of starch and hydroxyl-terminated polymethylethoxysiloxane Calculated according to the pyrolysis rate of starch and hydroxyl-terminated polymethylethoxysiloxane under the same experimental conditions. Heat to 300° C. while stirring, and keep for 2 hours, and the precursor is formed after the polysiloxane is cured. Put the crucible containing the precursor into the high-temperature furnace, and...

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Abstract

The invention relates to a composite negative material for a lithium ion battery and a preparation method of the composite negative material. The composite material is formed by compounding at least one of SiCO, SiCNO, SiCN and SiBC, Li4Ti<5-x>MxO<12-y>Fy and C, wherein M is at least one of Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb, Mo, Ru, Pd, Rh, Ag, In, Sn, Sb, Pb, Bi and W, x is more than or equal to 0 and less than or equal to 0.5, and y is more than or equal to 0 and less than or equal to 0.5. The content of at least one of SiCO, SiCNO, SiCN and SiBCN in the composite negative material accounts for 0.2 to 20 percent of the total weight, the Li4Ti<5-x>MxO<12-y>Fy accounts for 80 to 99.8 percent of the total weight, and C accounts for 0 to 20 percent of the total weight. The total weight is the sum of the weight of at least one of SiCO, SiCNO, SiCN and SiBCN and the weight of Li4Ti<5-x>MxO<12-y>Fy. Carbon or a carbon precursor and Li4Ti<5-x>MxO<12-y>Fy are added into at least one organic silicon polymer of polysiloxane, polysilazane and polyborosilazane to obtain a mixture, and after the curing and cross-linking, the mixture is pyrolyzed to obtain a composite material obtained by compounding at least one of SiCO, SiCNO, SiCN and SiBCN, Li4Ti<5-x>MxO<12-y>Fy and C. Compared with the Li4Ti<5-x>MxO<12-y>Fy, the composite material has the advantages that the compaction density and the electrochemical property of the composite material are remarkably improved.

Description

technical field [0001] The invention mainly relates to a composite negative electrode material for a lithium ion battery and a preparation method thereof, and belongs to the technical field of lithium ion battery negative electrode material preparation. Background technique [0002] Since Sony Corporation of Japan developed lithium-ion batteries using petroleum coke as the negative electrode in 1990, carbon materials have attracted people's attention. The varieties include artificial graphite, natural graphite, mesocarbon microspheres, petroleum coke, carbon fiber, etc., which are commercialized Lithium-ion battery main negative electrode material. However, carbon materials have the following disadvantages: 1. React with the electrolyte to form an SEI film, resulting in low initial charge and discharge efficiency; 2. Lithium metal is easy to deposit on the surface of the negative electrode, and there is no obvious voltage indication at the end of charging, which is easy to c...

Claims

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Application Information

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IPC IPC(8): H01M4/36H01M4/485H01M4/62H01M10/0525H01M4/1315
CPCH01M4/1315H01M4/13915H01M4/362H01M4/485H01M4/62H01M10/0525H01M2004/027Y02E60/10
Inventor卢世刚阚素荣袁敏娟张向军黄斌刘莎
OwnerCHINA AUTOMOTIVE BATTERY RES INST CO LTD