Confined Interlayer Water Promotes Structural Stability for High-Rate Electrochemical Proton Intercalation in Tungsten Oxide Hydrates
Confined Interlayer Water Promotes Structural Stability for High-Rate Electrochemical Proton Intercalation in Tungsten Oxide Hydrates
复制标题
受限层间水促进氧化钨水合物中高速电化学质子插层的结构稳定性
DOI：
10.1021/acsenergylett.9b02040
复制
发表时间：
2019-12-01
影响因子：
22
通讯作者：
Augustyn, Veronica
中科院分区：
文献类型：
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作者：
Mitchell, James B.;Geise, Natalie R.;Augustyn, Veronica
人们对确定能够同时实现高功率和高能量密度的氧化还原活性电化学能量储存材料的结构特征有广泛的兴趣。在这里，我们提出的发现，限制层间水结晶氧化钨水合物，WO3中心点nH（2）O，使高度可逆的质子嵌入在亚秒级的时间尺度。通过比较结构转换动力学和承压水动力学的水合物与无水WO3，我们确定，快速电化学质子嵌入是由于承压水层的能力，隔离结构转换到两个维度，同时稳定结构沿着第三维。因此，这些水层提供了结构灵活性和稳定性，以适应嵌入驱动的键合变化。这为结合结构水的材料的快速储能动力学提供了另一种解释，并提供了一种新的策略，用于实现含有受限流体的氧化还原活性层状材料的高功率和高能量密度。
There is widespread interest in determining the structural features of redox-active electrochemical energy storage materials that enable simultaneous high power and high energy density. Here, we present the discovery that confined interlayer water in crystalline tungsten oxide hydrates, WO3 center dot nH(2)O, enables highly reversible proton intercalation at subsecond time scales. By comparing the structural transformation kinetics and confined water dynamics of the hydrates with anhydrous WO3, we determine that the rapid electrochemical proton intercalation is due to the ability of the confined water layers to isolate structural transformations to two dimensions while stabilizing the structure along the third dimension. As a result, these water layers provide both structural flexibility and stability to accommodate intercalation-driven bonding changes. This provides an alternative explanation for the fast energy storage kinetics of materials that incorporate structural water and provides a new strategy for enabling high power and high energy density with redox-active layered materials containing confined fluids.