Rejuvenating propylene carbonate-based electrolytes by regulating the coordinated structure toward all-climate potassium-ion batteries

Abstract

Potassium-ion batteries (PIBs) suffer from a restricted desolvation process, unstable interfaces and severe capacity deterioration at extreme temperatures, which hinders their application as an alternative technology to lithium-ion batteries. Herein, by regulating the ion–solvent-coordinated structure, substantial ion-pairs and aggregates are formed while the solvent-separated ion pairs are reduced, enabling a KF-rich interface and a low desolvation barrier to improve wide-temperature performance. Consequently, the designed propylene carbonate-based electrolyte rejuvenates graphite anodes, delivering a high reversible capacity of ∼220 mA h g⁻¹ without attenuation at 0–60 °C. Moreover, graphite‖K–FeHCFe full cells can fully restore their original capacity at 0 °C and 25 °C even after operation at 60 °C and −20 °C. Remarkably, the full cells also exhibit a high room-temperature capacity retention of ∼63.7 mA h g⁻¹ (66.6%) at −20 °C and achieve stable cycling over 1000 cycles at 0 °C (capacity retention of 92.1%), 25 °C (85.7%) and 60 °C (85.3%). This work rejuvenates propylene carbonates in graphite-based all-climate potassium-ion batteries, thereby promoting the development of a low-cost electrochemical energy storage system.