Non-aqueous electrolyte secondary battery having positive electrode with high potential

摘要

The storage characteristics in a charged state are improved in a non-aqueous electrolyte secondary battery containing a lithium cobalt oxide as a positive electrode active material. The non-aqueous electrolyte secondary battery includes a positive electrode containing a positive electrode active material; a negative electrode containing a negative electrode active material other than metallic lithium; and a non-aqueous electrolyte. The positive electrode active material contains a lithium cobalt oxide as its main component. The non-aqueous electrolyte contains 0.1 to 10 volume % of a compound having an ether group. The positive electrode active material and the negative electrode active material are contained so that the charge capacity ratio of the negative electrode to the positive electrode is from 1.0 to 1.2 when the battery is charged until the potential of the positive electrode reaches 4.4 to 4.5 V (vs. Li/Li⁺)