Cooperation Between Methyl Acetate Solvent and Binder Remarkably Improves the Low-Temperature Performance of the LiNi0.5Mn1.5O4 Cathode

Li4Ti5O12 (LTO)/LiNi0.5Mn1.5O4 (LNMO) batteries have appealing features, such as suitable energy density and high safety. A proper binder of the LNMO cathode and electrolyte can improve the performance of batteries. Herein, we first combined the polyacrylic acid (PAA) binder with an ester-based electrolyte due to their homologous structure. This system has better performance than other binders of LNMO cathode, like poly(vinylidene fluoride) (PVDF), styrene–butadiene rubber (SBR), and polytetrafluoroethylene (PTFE). In the methyl acetate (MA) electrolyte, the LTO/LNMO battery with the PAA binder exhibited the highest discharge capacity (137 mAh g–1 at 0.5 C) and the best rate performance (112 mAh g–1 at 5 C). In addition, MA boosted the low-temperature performance of this battery, which can work at −40 °C with a remarkable reversible capacity of 90 mAh g–1 and a discharge capacity of 140 mAh g–1.