Silicon oxide material for nonaqueous electrolyte secondary battery negative electrode material, making method, negative electrode, lithium ion secondary battery, and electrochemical capacitor
OwnerHirofumi FUKUOKA, Meguru KASHIDA +2inventors
InventorsHirofumi FUKUOKA, Meguru KASHIDA, Satoru MIYAWAKI, Toshio OHBA
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Abstract
A silicon oxide material is obtained by cooling and precipitating a gaseous mixture of SiO gas and silicon-containing gas and has an oxygen content of 20-35 wt %. Using the silicon oxide material as a negative electrode active material, a nonaqueous electrolyte secondary battery is constructed that exhibits a high 1st cycle charge/discharge efficiency and improved cycle performance while maintaining the high battery capacity and low volume expansion of silicon oxide.
Claims7
A silicon oxide material for nonaqueous electrolyte secondary battery negative electrode material, which is obtained by cooling and precipitating a gaseous mixture of SiO gas and silicon-containing gas, and has an oxygen content of 20 to 35% by weight.
A method for preparing a silicon oxide material for nonaqueous electrolyte secondary battery negative electrode material, comprising the steps of:
- heating a SiO gas-providing raw material at a temperature in the range of 1,100 to 1,600° C. in the presence of an inert gas or in vacuum to generate a SiO gas,
- adding a silicon-containing gas to the SiO gas to form a gaseous mixture,
- cooling and precipitating the gaseous mixture, and
- recovering the precipitate.
Dependencies are inferred from the claim text.