Nonaqueous electrolyte secondary battery

Abstract

The present disclosure provides a technology of eliciting the heat generation suppressing effect of trilithium phosphate (Li3PO4) in a 4 V class battery stably. The nonaqueous electrolyte secondary battery disclosed herein includes a positive electrode having a positive electrode mixture material layer, a negative electrode, and a nonaqueous electrolyte. The positive electrode has a region with an open voltage of 4.25 V (Li/Li+) or less in an operating range of the battery. The positive electrode mixture material layer includes a positive electrode active material, trilithium phosphate (Li3PO4), and lithium dihydrogenphosphate (LiH2PO4). In the nonaqueous electrolyte secondary battery disclosed herein, in an XRD pattern of the positive electrode mixture material layer, a peak intensity IA detected near 27 cm−1, and a peak intensity B detected near 22 cm−1 satisfy 0<IA/IB≤0.03. This prevents decomposition of Li3PO4 and gelation of the positive electrode mixture material layer, and the heat generation suppressing effect by Li3PO4 can be stably elicited.

Dependencies are inferred from the claim text.