There is an urgent need for low-cost, resource-friendly, high-energy-density cathode materials for lithium-ion batteries to satisfy the rapidly increasing need for electrical energy storage. To replace the nickel and cobalt, which are limited resources and are associated with safety problems, in current lithium-ion batteries, high-capacity cathodes based on manganese would be particularly desirable owing to the low cost and high abundance of the metal, and the intrinsic stability of the Mn4+ oxidation state. Here we present a strategy of combining high-valent cations and the partial substitution of fluorine for oxygen in a disordered-rocksalt structure to incorporate the reversible Mn2+/Mn4+ double redox couple into lithium-excess cathode materials. The lithium-rich cathodes thus produced have high capacity and energy density. The use of the Mn2+/Mn4+ redox reduces oxygen redox activity, thereby stabilizing the materials, and opens up new opportunities for the design of high-performance manganese-rich cathodes for advanced lithium-ion batteries.Lithium-rich cathode materials in which manganese undergoes double redox could point the way for lithium-ion batteries to meet the capacity and energy density needs of portable electronics and electric vehicles.

中文翻译：

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锂过量正极材料中的可逆 Mn2+/Mn4+ 双氧化还原

迫切需要低成本、资源友好、高能量密度的锂离子电池正极材料，以满足快速增长的电能存储需求。为了替代资源有限且存在安全问题的镍和钴，在当前的锂离子电池中，由于金属的低成本和高丰度，基于锰的高容量阴极将是特别理想的。 Mn4+ 氧化态的内在稳定性。在这里，我们提出了一种在无序岩盐结构中结合高价阳离子和氟部分取代氧的策略，以将可逆的 Mn2+/Mn4+ 双氧化还原对结合到锂过量的正极材料中。由此生产的富锂阴极具有高容量和能量密度。