NEGATIVE ELECTRODE ACTIVE MATERIAL FOR NON-AQUEOUS ELECTROLYTE SECONDARY BATTERIES AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY USING NEGATIVE ELECTRODE ACTIVE MATERIAL

摘要

In a non-aqueous electrolyte secondary battery using SiOX as a negative electrode active material, it is an object to improve initial charge-discharge efficiency and cycle properties. Provided is a negative electrode active material containing particles made of SiOX containing a lithium silicate phase, 50% to 100% of the surface of each particle made of SiOX being covered by carbon. The proportion of the number of moles of the lithium silicate phase to the number of moles of the particles made of SiOX is 0.5 mole percent to 25 mole percent. The average primary particle size of the particles made of SiOX is 1 μm to 15 μm.

主权项

1. A negative electrode active material for non-aqueous electrolyte secondary batteries, comprising particles made of SiOX (0.8≦X≦1.2) containing a lithium silicate phase, wherein 50% to 100% of the surface of each particle made of SiOX is covered by carbon.