SULFUR-CONTAINING MATERIAL FOR POSITIVE ELECTRODE ACTIVE MATERIALS, LITHIUM ION SECONDARY BATTERY, METHOD OF CHARGING AND DISCHARGING LITHIUM ION SECONDARY BATTERY, AND COMPOSITION FOR FORMING POSITIVE ELECTRODE ACTIVE MATERIAL LAYER

Provided is a sulfur-containing material for positive electrode active materials of a lithium ion secondary battery, the sulfur-containing material for positive electrode active materials including a sulfur-modified compound. The sulfur-containing material for positive electrode active materials is used such that a discharge end potential of a positive electrode in a charge and discharge cycle of the lithium ion secondary battery is less than 1.0 V(Li/Li).