Non-aqueous electrolyte secondary battery, negative electrode material, and making method

摘要

A negative electrode material comprising an active material and 1-20 wt% of a polyimide resin binder is suitable for use in non-aqueous electrolyte secondary batteries. The active material comprises silicon oxide particles and 1-50 wt% of silicon particles. The negative electrode exhibits improved cycle performance while maintaining the high battery capacity and low volume expansion of silicon oxide. The non-aqueous electrolyte secondary battery has a high initial efficiency and maintains improved performance and efficiency over repeated charge/discharge cycles by virtue of mitigated volumetric changes during charge/discharge cycles.