Effects of a Sodium Phosphate Electrolyte Additive on Elevated Temperature Performance of Spinel Lithium Manganese Oxide Cathodes

Abstract

LiMn2O4 (LMO) spinel cathode materials suffer from severe degradation at elevated temperatures because of Mn dissolution. In this research, monobasic sodium phosphate (NaH2PO4, P2) is examined as an electrolyte additive to mitigate Mn dissolution; thus, the thermal stability of the LMO cathode material is improved. The P2 additive considerably improves the cyclability and storage performances of LMO/graphite and LMO/LMO symmetric cells at 60 °C. We explain that P2 suppresses the hydrofluoric acid content in the electrolyte and forms a protective cathode electrolyte interphase layer, which mitigates the Mn dissolution behavior of the LMO cathode material. Considering its beneficial role, the P2 additive is a useful additive for spinel LMO cathodes that suffer from severe Mn dissolution.

Achieving the Interface Stability of LiMn2O4 Cathode Using Aqueous Polyacrylic Acid/acrylate Copolymer and Nanoscale CaCO3 to Improve the High‐Temperature Cycling and Storage Performance of Lithium‐Ion Batteries

“…Up to now, several methods such as optimizing the electrolyte composition, regulating the LMO structure, and coating the LMO surface have been carried out to stabilize the LMO‐based batteries. [ 12–17 ] The doping of some elements into LMO can regulate the bulk structure and improve the cycle performance and stability of LMO. [ 18–21 ] The surface coating can generate a protective layer to stabilize the LMO–electrolyte interface and inhibit the dissolution of manganese ions.…”