Next-Generation Electrode Materials for Safe and Sustainable Manganese-Based Aqueous Batteries

Abstract

Lithium-ion batteriesface growing limitations for large-scale energy storage due to high cost, resource constraints, and safety concerns. In response, aqueous battery systems have emerged as compelling alternatives, offering intrinsic safety, low cost, and environmental sustainability. Among them, manganese-based aqueous batteries are particularly attractive, owing to manganese's earth abundance, low redox potential (−1.19 V vs. SHE), and high theoretical capacity. Nevertheless, the development of Mn-ion batteries is hindered by the large hydrated ionic radius and high desolvation energy of Mn2+, which severely restrict ion insertion kinetics and structural reversibility. This review critically examines recent advances in the design of electrode materials and electrolytes for aqueous Mn-based batteries. Emphasis is placed on interfacial challenges at Mn metal anodes, strategies to suppress side reactions, and criteria for enabling reversible Mn2+ storage. A broad range of cathode materials—including vanadium oxides, vanadium bronzes, Fe-based compounds, and organic frameworks—are evaluated with respect to their crystallographic architectures, ion diffusion pathways, and redox mechanisms. Through systematic comparison of structure–property–performance relationships, this review highlights current limitations and outlines promising directions for the development of high-energy, long-cycle-life aqueous Mn-ion batteries.