SULFUR-MODIFIED POLYACRYLONITRILE AND EVALUATION METHOD THEREFOR, POSITIVE ELECTRODE USING SULFUR-MODIFIED POLYACRYLONITRILE, NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY, AND VEHICLE

摘要

The present invention addresses the problem of providing sulfur-modified polyacrylonitrile that improves the charge-discharge capacity of a non-aqueous electrolyte secondary battery, and an evaluation method for selecting such sulfur-modified polyacrylonitrile. As the sulfur-modified polyacrylonitrile, the one in which the area occupied by particles having a grain size of 1 µm or less and/or the aggregate of such particles is 80% or more in the imaging area ratio of all particles, is selected.