Revealing the effect mechanism of mesopore content on carbon anodes for potassium ions storage

Abstract

The abundance of inherent micropores in biomass-based carbon restricts potassium ion transport, which in turn hinders both adsorption and intercalation kinetics. Increasing mesopore content can significantly enhance potassium ion transport, but quantitative regulation of mesoporous content remains challenging. Furthermore, the mechanism by which mesopore content affects reaction kinetics is not fully understood. In this work, carbon anodes with controlled mesopore content were synthesized by replicating SBA-15 zeolite structures via a coating method. For the first time, the relationship between mesopore content and potassium-ion storage performance is systematically explored. The increase in the mesopore content can both improve the enhance adsorption and intercalation kinetics, thereby improve the discharge capacity. However, excessive mesopores reduce the adsorption ratio, negatively impacting cycling stability. Therefore, an appropriate mesoporous content exhibits the best performance. This study offers a strategy for the regulation of mesopore content in carbon anodes and provides new insights into the role of mesopore content in enhancing potassium ions storage performance.