Mg‐ion batteries (MIBs) are promising next‐generation secondary batteries, but suffer from sluggish Mg2+ migration kinetics and structural collapse of the cathode materials. Here, an H2O‐Mg2+ waltz‐like shuttle mechanism in the lamellar cathode, which is realized by the coordination, adaptive rotation and flipping, and co‐migration of lattice H2O molecules with inserted Mg2+, leading to the fast Mg2+ migration kinetics, is reported; after Mg2+ extraction, the lattice H2O molecules rearrange to stabilize the lamellar structure, eliminating structural collapse of the cathode. Consequently, the demo cathode of Mg0.75V10O24·nH2O (MVOH) exhibits a high capacity of 350 mAh g−1 at a current density of 50 mA g−1 and maintains a capacity of 70 mAh g−1 at 4 A g−1. The full aqueous MIB based on MVOH delivers an ultralong lifespan of 5000 cycles The reported waltz‐like shuttle mechanism of lattice H2O provides a novel strategy to develop high‐performance cathodes for MIBs as well as other multivalent‐ion batteries.

中文翻译：

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H2O-Mg2+ 华尔兹式穿梭使高容量和超长寿命的镁离子电池成为可能

镁离子电池（MIB）是有前途的下一代二次电池，但镁离子电池发展缓慢2+正极材料的迁移动力学和结构崩溃。这里，一个H2我的天啊2+层状阴极中的华尔兹式穿梭机制，是通过晶格H的协调、自适应旋转和翻转以及共迁移来实现的2插入 Mg 的 O 分子2+，导致快速 Mg2+据报道，迁移动力学；镁后2+提取，格子H2O分子重新排列以稳定层状结构，消除阴极的结构崩溃。因此，镁的演示阴极0.75V10氧24·nH2O (MVOH) 表现出 350 mAh g 的高容量−1电流密度为 50 mA g−1并保持 70 mAh g 的容量−14A g 时−1。基于 MVOH 的全水性 MIB 具有 5000 次循环的超长寿命 报道的晶格 H 的华尔兹式穿梭机制2O 提供了一种为 MIB 以及其他多价离子电池开发高性能阴极的新策略。