Hybrid Mg²⁺/Li⁺ batteries featuring dendrite-free Mg anode and Li-storage cathode are promising safe energy storage systems. However, improving the energy density remains a grand challenge due to the quite limited capacities of traditional Li-intercalation cathodes. To circumvent this limitation, a new type of conversion cathode for hybrid Mg²⁺/Li⁺ batteries, microflower-like Cu₉S₅, is reported herein. The Cu₉S₅ cathode is compatible with the dual-salt Mg²⁺/Li⁺ electrolyte, and delivers a high reversible capacity of 300 mAh g⁻¹ at 50 mA g⁻¹ via electrochemical conversion reaction, with 94% capacity retention over 100 cycles in hybrid Mg²⁺/Li⁺ batteries. The electrode also shows an outstanding rate capability providing 155 mAh g⁻¹ at 1000 mA g⁻¹ and a superior long-term cycleability over 1000 cycles. This excellent performance is attributed to the hierarchical architecture of Cu₉S₅ which facilitates the reversible conversion reactions and stabilizes the electrode structure during discharge/charge process. This work provides new insight for the nanostructure design of stable conversion electrodes, and opens a new avenue for building safe and high-performance hybrid Mg²⁺/Li⁺ batteries for practical applications.

具有无枝晶镁阳极和锂存储阴极的混合镁²⁺ /锂⁺电池是有前途的安全储能系统。然而，由于传统的锂嵌入阴极的容量非常有限，因此提高能量密度仍然是一个巨大的挑战。为了克服该限制，本文报道了用于混合Mg ²⁺ / Li ⁺电池的新型转化阴极，即微花状的Cu ₉ S ₅。Cu ₉ S ₅阴极与双盐Mg ²⁺ / Li ⁺电解质兼容，并 在50 mA g ^-1下提供300 mAh g ^-1的高可逆容量通过电化学转化反应，混合Mg ²⁺ / Li ⁺电池在100个循环中可保持94％的容量。电极还显示出出色的速率能力， 在1000 mA g ^-1时可提供155 mAh g ^-1，在1000次循环中具有出色的长期循环能力。优异的性能归因于Cu ₉ S ₅的层级结构，该层级结构有助于可逆转换反应并在放电/充电过程中稳定电极结构。这项工作为稳定转换电极的纳米结构设计提供了新见识，并为构建安全，高性能的混合Mg ²⁺ / Li ⁺开辟了一条新途径。 实际应用中的电池。