Carbon-based materials for potassium-ion battery anodes: storage mechanisms and engineering strategies

Recently, potassium-ion batteries (PIBs) have received significant attention in the energy storage field owing to their high-power output, fast charging capability, natural abundance, and environmental sustainability. Herein, we comprehensively review recent advancements in the design and development of carbon-based anode materials for PIBs anodes, covering graphite, hard carbon, alloy and conversion materials with carbon, and carbon host for K metal deposition. Chemical strategies such as structural engineering, heteroatom-doping, and surface modifications are highlighted to improve electrochemical performances as well as to resolve technical challenges, such as electrode instability, low initial Coulombic efficiency, and electrolyte compatibility. Furthermore, we discuss the fundamental understanding of potassium-ion storage mechanisms of carbon-based materials and their correlation with electrochemical performance. Finally, we present the current challenges and future research directions for the practical implementation of carbon-based anodes to enhance their potential as next-generation energy storage materials for PIBs. This review aims to provide our own insights into innovative design strategies for advanced PIB’s anode through the chemical and engineering strategies.