Challenges and design strategies for alloy-based anode materials toward high-performance future-generation potassium-ion batteries

Potassium-ion batteries (PIBs) are a promising candidate for low-cost and large-scale energy storage due to their abundant potassium resources. However, the potassiation-depotassiation of K+ presents a significant challenge due to its large ionic radius, which results in the pulverization of active materials and poor cyclability. Thus, researchers are exploring anode materials with a high specific capacity, long cyclability, and excellent rate capability. In this context, alloy-type anode materials are exceptional candidates due to their high theoretical capacity and low working potential. Nonetheless, the large volume expansion of active materials limits their practical application. This review discusses various strategies for overcoming these challenges, including nanostructure design, heterostructure design, alloy engineering, and compositing. The review provides a comprehensive overview of the current state of research on alloy-based anodes for PIBs and offers insights into promising directions for future work toward commercializing PIBs.