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

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 similar to 220 mA h g(-1) without attenuation at 0-60 degrees C. Moreover, graphite vertical bar vertical bar K-FeHCFe full cells can fully restore their original capacity at 0 degrees C and 25 degrees C even after operation at 60 degrees C and -20 degrees C. Remarkably, the full cells also exhibit a high room-temperature capacity retention of similar to 63.7 mA h g(-1) (66.6%) at -20 degrees C and achieve stable cycling over 1000 cycles at 0 degrees C (capacity retention of 92.1%), 25 degrees C (85.7%) and 60 degrees 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.

Automated summary

This study improves the performance limitations of potassium-ion batteries at extreme temperatures by regulating the ion-solvent-coordinated structure, leading to enhanced cycling performance and capacity retention.