Negative electrode active material for non-aqueous electrolyte secondary battery and method for manufacturing the same

摘要

The present invention provides a method for manufacturing a negative electrode active material for a secondary battery that uses a non-aqueous electrolyte, including the steps of: depositing silicon according to an electron beam vapor-deposition method with metallic silicon as a raw material on a substrate of which temperature is controlled from 800 to 1100°C at a vapor deposition rate exceeding 1 kg/hr in the range of film thickness of 2 to 30 mm; and pulverizing and classifying the deposited silicon to obtain the negative electrode active material. As a result, there is provided a method for manufacturing a negative electrode active material of silicon particles as an active material useful for a negative electrode of a non-aqueous electrolyte secondary battery that is, while maintaining high initial efficiency and battery capacity of silicon, excellent in the cycle characteristics and has a reduced volume change during charge/discharge.