Toward high-energy Mn-based disordered-rocksalt Li-ion cathodes

The recent development of high-capacity disordered-rocksalt (DRX) cathodes has ushered in new opportunities toward low-cost and high-energy Li-ion batteries. In particular, Mn-based DRX materials in which Mn serves as the primary redox-active transition metal have shown the most promising performance, with capacity and specific energy surpassing those of more established cathode materials. However, there remain critical challenges for these materials to become practical alternatives to conventional cathodes, such as limited cycling kinetics, which require pulverized particle morphology to achieve high capacity or poor capacity retention. Herein, we summarize the current understanding of the operating principles, failure mechanisms, synthesis and processing, microstructure, and performance of the Mn-based DRX materials. From this understanding, we perform a critical analysis of the challenges and opportunities toward high-energy Mn-based DRX for sustainable Li-ion batteries.