Anchoring active sulfur/selenium into enhanced carbon hosts with multiple chemical affinities for efficient K–S/Se batteries

Abstract

Potassium–sulfur (K–S) and potassium–selenium (K–Se) batteries, with high energy density and low cost, are considered promising options for grid-scale energy storage systems. However, challenges such as the notorious dissolution of polysulfides/polyselenides result in corrosion of potassium and cycle life decay, limiting their practical application. Herein, enhanced carbon hosts with multiple chemical affinities are constructed for encapsulating S or Se species toward a stable potassium ion storage. The unique design allows for the high loading (∼60 wt%) of active S or Se via enhanced chemical affinities originating from abundant nitrogen and oxygen groups. Moreover, the introduction of an N-reinforced O-site on a carbon substance can provide good electrical conductivity and alleviate the shuttling effect during the electrochemical process. Besides, in situ Raman and visualization tests also verify that the electrodes exhibit excellent electrochemical reversibility and cycling stability. The optimized cathode exhibits conspicuous performance in K–S and K–Se batteries. This work provides a practical strategy and paves the way for viable applications of advanced alkali metal battery systems.