ACTIVE MATERIAL FOR SECONDARY BATTERIES, ELECTRODE FOR SECONDARY BATTERIES, SECONDARY BATTERY, BATTERY PACK, ELECTRIC VEHICLE, ELECTRIC POWER STORAGE SYSTEM, ELECTRIC MOTOR-DRIVEN TOOL, AND ELECTRONIC DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a secondary battery which allows excellent battery characteristics to be achieved.SOLUTION: A secondary battery comprises a positive electrode, a negative electrode including an active material, and an electrolyte. The active material includes a center part, and a coating part provided on the surface of the center part. The center part contains silicon (Si) as a constituent element, and the coating part contains carbon (C) and hydrogen (H) as constituent elements. In positive ion analysis of the coating part by Time-Of-Flight secondary ion mass spectrometry, at least one kind of positive ions expressed by CH(x and y satisfy the conditions, 2≤x≤6 and 3≤y≤9) are detected.