All-Climate High-Voltage Commercial Lithium-Ion Batteries Based on Propylene Carbonate Electrolytes.

Abstract

Propylene carbonate (PC)-based electrolytes have many attractive advantages over the commercially used ethylene carbonate (EC)-based electrolytes like a wider operating temperature and higher oxidation stability. Therefore, PC-based electrolytes become the potential candidate for lithium-ion batteries with higher energy density, longer lifespan, and better low- and high-temperature performance. In spite of the superiority, PC is incompatible with the graphite anode because PC fails to passivate the graphite anode, leading to severe decomposition and gas evolution, which seriously restrict the development of the PC-based electrolytes. Nevertheless, it is recently found that the usage of diethyl carbonate (DEC) as a cosolvent will greatly improve the anodic tolerance of PC to realize the reversible lithiation/delithiation of the graphite anode in the PC-based electrolyte. It is because DEC induces anions into the solvation shell of Li+ to form an anion-induced ion-solvent-coordinated (AI-ISC) structure with higher reduction stability. In this work, we fabricated 4.4 V pouch cells to assess in detail the practical viability of the PC-based electrolyte in a commercial battery system. In comparison to conventionally used EC-based cells, the pouch cells with the PC-based electrolyte exhibit more excellent high-voltage tolerance and electrochemical performance at all temperature ranges (-40 to 85 °C), demonstrating the wide application prospect of the PC-based electrolyte.