Alkali Metal Ion Substituted Carboxymethyl Cellulose as Anode Polymeric Binders for Rapidly Chargeable Lithium‐Ion Batteries

Abstract

The increasing demand for short charging time on electric vehicles has motivated realization of fast chargeable lithium‐ion batteries (LIBs). However, shortening the charging time of LIBs is limited by Li+ intercalation process consisting of liquid‐phase diffusion, de‐solvation, SEI crossing, and solid‐phase diffusion. Herein, we propose a new strategy to accelerate the de‐solvation step through a control of interaction between polymeric binder and solvent‐Li+ complexes. For this purpose, three alkali metal ions (Li+, Na+, and K+) substituted carboxymethyl cellulose (Li‐, Na‐, and K‐CMC) are prepared to examine the effects of metal ions on their performances. The lowest activation energy of de‐solvation and the highest chemical diffusion coefficient were observed for Li‐CMC. Specifically, Li‐CMC cell with a capacity of 3 mAh cm−2 could be charged to >95% in 10 min, while a value above >85% was observed after 150 cycles. Thus, the presented approach holds great promise for the realization of fast charging.