Aqueous zinc-ion batteries are promising candidates for grid-scale energy storage because of their intrinsic safety, low cost, and high energy intensity. However, lack of suitable cathode materials with both excellent rate performance and cycling stability hinders further practical application of aqueous zinc-ion batteries. Here, a nanoflake-self-assembled nanorod structure of Ca0.28 MnO2 ·0.5H2 O as Zn-insertion cathode material is designed. The Ca0.28 MnO2 ·0.5H2 O exhibits a reversible capacity of 298 mAh g-1 at 175 mA g-1 and long-term cycling stability over 5000 cycles with no obvious capacity fading, which indicates that the per-insertion of Ca ions and water can significantly improve reversible insertion/extraction stability of Zn2+ in Mn-based layered type material. Further, its charge storage mechanism, especially hydrogen ions, is elucidated. A comprehensive study suggests that the intercalation of hydrogen ions in the first discharge plat is controled by both pH value and type of anion of electrolyte. Further, it can stabilize the Ca0.28 MnO2 ·0.5H2 O cathode and facilitate the following insertion of Zn2+ in 1 m ZnSO4 /0.1 m MnSO4 electrolyte. This work can enlighten and promote the development of high-performance rechargeable aqueous zinc-ion batteries.

中文翻译：

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层状Ca0.28 MnO2·0.5H2 O，作为水性锌离子电池的高性能阴极。

锌离子水电池因其固有的安全性，低成本和高能量强度而成为电网规模储能的有希望的候选者。然而，缺乏具有优异的倍率性能和循环稳定性的合适的阴极材料阻碍了水性锌离子电池的进一步实际应用。在此，设计了Ca0.28 MnO2·0.5H2 O的纳米薄片自组装纳米棒结构作为插入锌的阴极材料。Ca0.28 MnO2·0.5H2 O在175 mA g-1时表现出298 mAh g-1的可逆容量，并且在5000次循环中具有长期循环稳定性，并且没有明显的容量衰减，这表明每次插入Ca离子水可以显着提高Mn基层状材料中Zn2 +的可逆插入/提取稳定性。此外，它的电荷存储机制，尤其是氢离子，阐明了。一项综合研究表明，氢离子在第一个放电板中的嵌入受pH值和电解质阴离子类型的控制。此外，它可以稳定Ca0.28 MnO2·0.5H2 O阴极，并便于随后将Zn2 +插入1 m ZnSO4 /0.1 m MnSO4电解质中。这项工作可以启发和促进高性能可充电水性锌离子电池的发展。