Antimony-based materials for supercapacitor applications: A focused review

Antimony (Sb) is at the forefront of advancing energy storage due to its remarkable conductivity and unique puckered structure, boasting a considerable theoretical capacity of 660 mA h g⁻¹. These properties make it the perfect candidate for powering next-generation Li- and Na-ion batteries, as well as supercapacitors (SCs). Outshining graphite, antimony offers a significantly higher theoretical capacity and a safer reaction potential. Unlike Si, Ge, and Sn, which undergo severe volume expansion during alloying reactions, Sb experiences comparatively moderate volume changes, resulting in a more stable reaction pathway and better structural integrity during cycling. This review provides a comprehensive overview of both the synthesis strategies and electrochemical SC performance of Sb-based materials, including Sb oxides/chalcogenides and their composites, monometallic antimonene and its composites, and bimetallic Sb alloys, showcasing practical design approaches for high-performance Sb-based SC electrodes. Notably, recent studies report exceptionally high specific capacities—for instance, antimonene/3D-Ni electrodes achieving 1618.41 mA h g⁻¹(≈6854.45 F g⁻¹)—along with energy densities up to 131.44 Wh kg⁻¹for bismuthene/antimonene nanosheets-based electrodes. Moreover, it provides a beginner-friendly guide to SC performance testing, metrics, and insights into analyzing electrode mechanisms and electrochemical reactions. Furthermore, this review examines the current challenges and provides a critical assessment of the prospects for Sb-based SC electrodes, highlighting key knowledge gaps that must be addressed for the practical integration of these devices. Importantly, the review consolidates scattered findings across synthesis, structure–property relationships, and electrochemical behavior, offering a unified framework for accelerating the rational design of next-generation Sb-based SCs.