With the increasing demand for electrical energy storage, a new Mg−Li hybrid battery with Mg anode is regarded as a promising candidate because of low cost, high volumetric capacity, and dendrite‐free nature of the Mg anode. Nevertheless, the characteristics of low operation voltage and low energy density for Mg−Li hybrid batteries hinders their widespread application, owing to limited reversible cathodes. To overcome these issues, a highly reversible fast Li⁺ insertion cathode with high voltage is an effective strategy to realize high‐energy‐density Mg−Li hybrid batteries. Herein, we develop the 2 V high‐voltage spinel Li₄Mn₅O₁₂ cathode material with unique nano‐/microspheres, using a novel low‐temperature method, offering a short Li‐diffusion path and sufficient transport channels for electrolyte penetration into the electrode. For the first time, we demonstrate the feasibility of the spinel Li₄Mn₅O₁₂ nano‐/microspheres with hierarchical architecture as a cathode for 2 V hybrid Mg−Li batteries. It exhibits a reversible specific capacity of 155 mAh g⁻¹ and a long discharge voltage platform exceeding 2.0 V (vs. Mg/Mg²⁺) coupled with high energy density of 326 Wh kg⁻¹ at a current density of 0.1 C (1 C=163 mA g⁻¹). Our results pave the way of constructing new hybrid Mg−Li batteries with high voltage and high energy density.

中文翻译：

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尖晶石Li4Mn5O12作为用于镁基混合离子电池的2.0 V插入材料

随着对电能存储的需求不断增加，具有镁阳极的新型Mg-Li混合电池由于其低成本，高容量和无Mg阳极的特性而被认为是有前途的候选产品。然而，由于有限的可逆阴极，Mg-Li混合电池的低工作电压和低能量密度的特性阻碍了它们的广泛应用。为了克服这些问题，具有高电压的可逆快速锂⁺插入正极是实现高能量密度Mg-Li混合电池的有效策略。在这里，我们开发了2 V高压尖晶石Li ₄ Mn ₅ O ₁₂具有新颖纳米/微球的阴极材料，采用新颖的低温方法，可提供短的Li扩散路径和足够的传输通道，以使电解质渗透到电极中。首次，我们证明了具有尖峰结构的尖晶石Li ₄ Mn ₅ O ₁₂纳米/微球作为2 V混合Mg-Li电池阴极的可行性。它具有155 mAh g ^-1的可逆比容量和超过2.0 V（vs. Mg / Mg ²⁺）的长放电电压平台，并在电流密度为0.1 C时具有326 Wh kg ^-1的高能量密度（1 C = 163 mA g ^-1）。我们的结果为构建具有高电压和高能量密度的新型混合Mg-Li电池铺平了道路。