ZnCl2 “Water‐in‐Salt” Electrolyte Transforms the Performance of Vanadium Oxide as a Zn Battery Cathode
ZnCl2 “Water‐in‐Salt” Electrolyte Transforms the Performance of Vanadium Oxide as a Zn Battery Cathode
复制标题
DOI：
10.1002/adfm.201902653
复制
发表时间：
2019-05
影响因子：
19
通讯作者：
Lu Zhang;Ismael A. Rodríguez‐Pérez;Heng Jiang;Chong Zhang;Daniel P. Leonard;Qiubo Guo;Wenfeng Wang-Wenfeng-Wan
中科院分区：
文献类型：
--
作者：
Lu Zhang;Ismael A. Rodríguez‐Pérez;Heng Jiang;Chong Zhang;Daniel P. Leonard;Qiubo Guo;Wenfeng Wang-Wenfeng-Wan
在水性电池中，锌电池具有潜在的最高能量密度，具有固有的安全性、廉价性和可持续性。然而，大多数锌电池的正极材料都存在容量衰减的问题，特别是在低电流速率下。本文表明，ZnCl2“水-盐”电解质（WiSE）通过促进Ca0.20V2O5∙0.80H2O的锌电池阴极的前所未有的性能，在很大程度上解决了这一容量衰退问题。当ZnCl2水溶液浓度从1 m增加到30 m时，Ca0.20V2O5∙0.80H2O的容量从296 mAh g−1增加到496 mAh g−1；其绝对工作电位提高了0.4 V，最重要的是，在50 mA g−1的低电流下，即C/10；经过100次循环后，容量保持率从8.4%提高到51.1%。非原位表征结果表明，在稀释电解质中，电极上形成了一个新的ready - to -溶相。结果表明，基于锌的WiSE可以为锌电池在固定电网级存储中的应用提供基础平台。
Zn batteries potentially offer the highest energy density among aqueous batteries that are inherently safe, inexpensive, and sustainable. However, most cathode materials in Zn batteries suffer from capacity fading, particularly at a low current rate. Herein, it is shown that the ZnCl2 “water‐in‐salt” electrolyte (WiSE) addresses this capacity fading problem to a large extent by facilitating unprecedented performance of a Zn battery cathode of Ca0.20V2O5∙0.80H2O. Upon increasing the concentration of aqueous ZnCl2 electrolytes from 1 m to 30 m, the capacity of Ca0.20V2O5∙0.80H2O rises from 296 mAh g−1 to 496 mAh g−1; its absolute working potential increases by 0.4 V, and most importantly, at a low current rate of 50 mA g−1, that is, C/10; its capacity retention increases from 8.4% to 51.1% over 100 cycles. Ex situ characterization results point to the formation of a new ready‐to‐dissolve phase on the electrode in the dilute electrolyte. The results demonstrate that the Zn‐based WiSE may provide the underpinning platform for the applications of Zn batteries for stationary grid‐level storage.