Latent Solvation Chemistry with Low Electrostatic Stickiness Enables Wide-Temperature Fast-Charging Lithium-Ion Batteries.

Abstract

Electrolytes for lithium-ion batteries commonly rely on static solvation structures that support ion dissociation and transport under mild conditions but lack the adaptability required across large temperature variations. Here, we establish latent solvation chemistry to construct a dynamically evolving solvation environment in which a suitably selected diluent remains weakly coordinated at room temperature but is recruited into the Li+ solvation shell upon cooling. Guided by lithiophilicity and electrostatic stickiness, we identify a diluent that combines temperature-activated Li+ coordination with favorable transport characteristics. Upon cooling, its recruitment into the Li+ solvation shell reorganizes the solvation environment, facilitating ion transport and interfacial charge transfer. The resulting electrolyte also forms a thin, LiF-rich interphase that supports efficient low-temperature Li+ transport. The designed electrolyte enables 5 C fast charging at -20°C and stable cycling at -50°C with a reversible capacity above 150 mAh g- 1. A 1.2 Ah pouch cell retains 91.04% of its initial capacity after 2000 cycles over more than 600 days. This work establishes latent solvation chemistry as a molecular design strategy for wide-temperature fast charging in lithium-ion batteries.