Facile fabrication of a covalently-bonded carbon–sulfur composite from lignin for high-capacity potassium storage

Abstract

A carbon–sulfur composite with covalently bonded short-chain sulfur (∼27.5 wt%) was facilely synthesized via a one-step low-temperature (450 °C) heat treatment of the biomass lignin and cyclo-S₈. As a K-ion battery anode, this composite exhibited a high reversible capacity of 596 mAh g⁻¹ with impressive rate capability and promising cyclability.