发明名称 |
Silicon composite, making method, and non-aqueous electrolyte secondary cell negative electrode material |
摘要 |
A silicon composite comprises silicon particles whose surface is at least partially coated with a silicon carbide layer. It is prepared by subjecting a silicon powder to thermal CVD with an organic hydrocarbon gas and/or vapor at 900-1,400° C., and heating the powder for removing an excess free carbon layer from the surface through oxidative decomposition. |
申请公布号 |
US9608262(B2) |
申请公布日期 |
2017.03.28 |
申请号 |
US201514635464 |
申请日期 |
2015.03.02 |
申请人 |
Shin-Etsu Chemical Co., Ltd. |
发明人 |
Aramata Mikio;Miyawaki Satoru;Fukuoka Hirofumi;Momii Kazuma;Urano Kouichi |
分类号 |
H01M4/36;H01M4/04;H01M4/13;H01M4/139;H01M4/38;H01M4/58;H01M4/134;H01M10/44;H01M10/052;H01M4/02 |
主分类号 |
H01M4/36 |
代理机构 |
Oblon, McClelland, Maier & Neustadt, L.L.P. |
代理人 |
Oblon, McClelland, Maier & Neustadt, L.L.P. |
主权项 |
1. A method of improving cycle retention in cyclic charge/discharge operation of a non-aqueous electrolyte secondary cell, comprising repeated charging and discharging of a lithium ion secondary cell comprising a positive electrode, a negative electrode, a non-aqueous electrolyte solution, and a separator, wherein said negative electrode comprises a negative electrode active material which comprises:
a silicon composite obtained by a thermal chemical vapor deposition treatment on silicon particles having an average particle size of from 50 nm to 50 μm at a temperature of 900° C. to 1,400° C. in a fluidizing gas atmosphere comprising a hydrocarbon or mono- to tri-cyclic aromatic hydrocarbon, to obtain a carbon/silicon carbide coated silicon powder, and heat-treating said carbon/silicon carbide coated silicon powder in an oxidizing atmosphere at a temperature of 600° C. to 1,400° C. to oxidatively decompose a surface layer of free carbon, wherein the silicon composite comprises silicon particles having an average particle size of from 50 nm to 50 μm whose surfaces are coated with a fused layer of silicon carbide and comprise free carbon in an amount of from 1.3 wt. % to 2 wt. % based on the total weight of said silicon composite, wherein said silicon carbide is present in an amount of from 10 wt. % to 58.3 wt. % based on the total weight of said silicon composite, wherein said silicon composite is in the form of a powder having an average particle size of from 0.08 μm to 52 μm, and wherein said silicon composite further comprises zero-valent silicon in an amount of from 39.9 wt. % to 90 wt. % based on the total weight of said silicon composite, wherein said zero-valent silicon is capable of generating hydrogen gas when reacted with an alkali hydroxide solution. |
地址 |
Tokyo JP |