Insight into Bi-Sb alloys and their chalcogenide compounds for sodium/potassium ion battery (SIB/PIB) anodes

Abstract

Sodium/potassium ion batteries (SIBs/PIBs), emerging as promising alternatives to lithium-ion batteries (LIBs), show great potential in large-scale electrical energy storage systems owing to their abundant reserves, potential cost advantages, and low standard redox potentials. In recent years, Bi-Sb alloys and their chalcogenide compounds (sulfides, selenides, and tellurides) have garnered significant attention due to their unique bimetallic synergistic effects and tunable energy storage mechanisms. This paper reviews the recent progress in Bi-Sb alloys and their chalcogenide compounds as anode materials for SIBs and PIBs. Highlighting the synergistic effects of Bi-Sb systems, the study emphasizes their high theoretical capacity, reduced volume expansion, and enhanced structural stability compared to monometallic counterparts. Key strategies such as nano-structuring (e.g., nanoporous and 2D layered architectures), composite engineering (e.g., carbon-based matrices), and heterostructure design are discussed to address challenges like electrode pulverization. The electrochemical mechanisms, including multi-step alloying and conversion reactions, are analyzed to elucidate performance enhancements in terms of cycling stability, rate capability, and capacity retention. Specifically, the paper examines the structural properties, modification strategies, and performance optimization mechanisms of these materials, and identifies key pathways for their engineering applications, aiming to provide theoretical support and technological references for designing high-capacity anode materials for SIBs/PIBs. Additionally, critical issues, challenges, and prospects for further development are suggested. This work provides critical insights into material design principles and offers pathways for developing next-generation, cost-effective energy storage technologies.