Potassium storage in bismuth nanoparticles embedded in N-doped porous carbon facilitated by ether-based electrolyte

Abstract

Potassium ion batteries (PIBs) advance as potential energy storage facilities. Proper electrode materials and suitable electrolyte match are key points all the time. Alloy electrode materials with high theoretical potassium storage draw great attention, in which metallic Bi (386 mAh g−1) is expected to perform exceptional properties in PIBs. Herein we show the Bi nanoparticles on N-doped porous carbon (Bi NPs/NPC) matching the DME-based electrolyte. The precise tailor of Bi content and the unique egg-carton shaped porous nanostructure effectively manifest the excellent properties. And the homogeneous SEI with elastic and thin nature formed in the DME-based electrolyte greatly maintains the durable cycling stability as well as swift kinetics behaviors. It possesses remarkable 362.4 mAh g−1 at 20 A g−1 (nearly 96.1% capacity retention based on 0.5 A g−1) for potassium storage. A series of ex-situ and in-situ characterization techniques comprehensively reflect inner reaction mechanism and interaction. Theoretical simulation further unravels the interplay between electrode materials and DME-based electrolyte. Practical application is further proved by the full PIBs with satisfying energy/power densities (105.1 Wh kg−1 at 5882.5 W kg−1). Insightful thoughts are offered to synthesize more outstanding Bi-based anodes.