Tailoring the alkyl chain length of linear esters in moderately concentrated electrolyte for a high-performance graphite anode in K-ion batteries

Abstract

K⁺ desolvation in moderately concentrated ester electrolytes becomes easier with a longer alkyl chain of the linear ester. An electrolyte of 2.4 M KFSI in an ethylene carbonate + butyl methyl carbonate mixture renders a graphite anode with a high capacity of 261 mA h g⁻¹ and 93% capacity retention after 500 cycles at 2C.