NaCa 0.6 V 6 O 16 ·3H 2 O as an Ultra‐Stable Cathode for Zn‐Ion Batteries: The Roles of Pre‐Inserted Dual‐Cations and Structural Water in V 3 O 8 Layer
NaCa 0.6 V 6 O 16 ·3H 2 O as an Ultra‐Stable Cathode for Zn‐Ion Batteries: The Roles of Pre‐Inserted Dual‐Cations and Structural Water in V 3 O 8 Layer
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NaCa 0.6 V 6 O 16 ·3H 2 O作为锌离子电池超稳定正极：V 3 O 8 层中预插入双阳离子和结构水的作用
DOI：
10.1002/aenm.201901968
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发表时间：
2019
影响因子：
27.8
通讯作者：
Huang, Kevin
中科院分区：
文献类型：
--
作者：
Zhu, Kaiyue;Wu, Tao;Huang, Kevin
以 Zn2+ 作为工作离子的可充电水电池因其本质安全、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，为了使锌离子电池（ZIB）找到实际应用，必须找到具有优异 Zn2+ 存储循环性能的合适正极材料。在此，NaCa0.6V6O16·3H2O (NaCaVO) 钾锰矿纳米带被报道为一种超稳定的 ZIB 正极材料。 0.1 A g−1 下原始容量达到 347 mAh g−1，2 A g−1 下循环 2000 次后容量保持率为 94%，5 A g−1 下循环 10 000 次后容量保持率为 83%。通过理论和实验相结合的方法，发现NaCaVO中独特的V3O8层状结构在能量上有利于Zn2+的扩散，并且位于V3O8层之间的结构水通过扩大通道间距和提供更多的Zn离子存储位点促进了Zn2+的快速电荷转移和整体迁移。研究还发现，V3O8层中交替存在的Na+和Ca2+是层状结构的重要稳定剂，在保持长期循环稳定性方面发挥着至关重要的作用。
Rechargeable aqueous batteries with Zn2+as a working‐ion are promising candidates for grid‐scale energy storage because of their intrinsic safety, low‐cost, and high energy‐intensity. However, suitable cathode materials with excellent Zn2+‐storage cyclability must be found in order for Zinc‐ion batteries (ZIBs) to find practical applications. Herein, NaCa0.6V6O16·3H2O (NaCaVO) barnesite nanobelts are reported as an ultra‐stable ZIB cathode material. The original capacity reaches 347 mAh g−1at 0.1 A g−1, and the capacity retention rate is 94% after 2000 cycles at 2 A g−1and 83% after 10 000 cycles at 5 A g−1, respectively. Through a combined theoretical and experimental approach, it is discovered that the unique V3O8layered structure in NaCaVO is energetically favorable for Zn2+diffusion and the structural water situated between V3O8layers promotes a fast charge‐transfer and bulk migration of Zn2+by enlarging gallery spacing and providing more Zn‐ion storage sites. It is also found that Na+and Ca2+alternately suited in V3O8layers are the essential stabilizers for the layered structure, which play a crucial role in retaining long‐term cycling stability.