Innovative conversion electrode materials and electrolyte strategies in aqueous zinc–S/Se batteries for advanced energy storage

Abstract

Aqueous zinc-ion batteries (AZIBs) are promising candidates for next-generation energy storage systems due to their inherent safety, low cost, environmental friendliness, and high theoretical capacity. However, conventional cathode materials mainly operate via ion-insertion mechanisms, which limit the achievable capacity and fail to fully exploit the potential of AZIBs. Sulfur-based cathodes employing conversion-type mechanisms can fully harness the theoretical capacity of zinc anodes. Rechargeable aqueous zinc–sulfur (AZSBs) and zinc–selenium batteries (AZSeBs) combine the advantages of sulfur or sulfur-based cathodes (S: 1672 mA h g⁻¹, Se: 678 mA h g⁻¹) with zinc anodes, significantly enhancing energy density and drawing increasing research interest. However, the commercialization of AZSBs and AZSeBs encounters several challenges, including poor conductivity, volume changes and slow reaction kinetics. Although research on AZSBs and AZSeBs remains in its infancy, significant progress has been achieved through rational design and optimization strategies. Recent advancements in performance enhancement strategies for AZSBs and AZSeBs are summarized, covering cathode optimization, electrolyte modification, advanced characterization methods, and elucidation of reaction mechanisms. The persisting challenges and potential development pathways of AZSBs and AZSeBs are also discussed.