Organic cathodes for rechargeable magnesium metal batteries: materials, mechanisms, and prospects

storage. This review systematically categorizes organic cathode materials into small molecules, small molecular salts, and polymers, with the latter further classified into polyanthraquinones, polyimides, covalent organic frameworks (COFs), and metal organic frameworks (MOFs). Small molecules such as 2,5-dimethoxy-1,4-benzoquinone (DMBQ) and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) demonstrate high specific capacities but suffer from dissolution issues, necessitating strategies like electrolyte engineering and separator modification to mitigate shuttling effects. Polymer-based cathodes, including polyanthraquinonyl sulfide (PAQS) and polyimides (PIs), exhibit enhanced cycling stability due to their low solubility and robust structures. Networked polymers, including COFs and MOFs, further improve performance through ordered porous structures and efficient ion transport pathways. This review comprehensively discusses the redox mechanisms, electrochemical performance, and degradation pathways of various organic cathodes, highlighting structure-property relationships and innovative design strategies. Future perspectives are provided to guide the development of high-performance, sustainable organic cathodes for RMBs.