Understanding intercalation chemistry for sustainable aqueous zinc–manganese dioxide batteries
Understanding intercalation chemistry for sustainable aqueous zinc–manganese dioxide batteries
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DOI：
10.1038/s41893-022-00919-3
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发表时间：
2022-08
影响因子：
27.6
通讯作者：
Yifei Yuan;R. Sharpe;Kun He;Chenghang Li-;Mahmoud Tamadoni Saray;Tongchao Liu;Wentao Yao;M. Cheng
中科院分区：
文献类型：
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作者：
Yifei Yuan;R. Sharpe;Kun He;Chenghang Li-;Mahmoud Tamadoni Saray;Tongchao Liu;Wentao Yao;M. Cheng
可充电水性 Zn-MnO2 技术结合了最古老的电池化学成分之一和良好的可持续性特性，包括安全性、成本和环境兼容性。然而，不明确的电荷存储机制对发挥这种能源技术的巨大潜力提出了挑战。在这里，我们利用先进的电子显微镜、电化学分析和理论计算来研究阴极材料（更具体地说是 α-MnO2）内的插层化学。我们表明，在水体系中，Zn2+ 不太可能插入阴极；相反，电荷存储过程主要是质子嵌入形成α-HxMnO2。我们进一步揭示了质子从表面进入 α-MnO2 本体时导致的各向异性晶格变化，这解释了循环时电极的结构失效和容量衰减。我们的工作不仅增进了对可充电锌电池的基本理解，而且还提出了优化质子嵌入动力学以实现性能更好的电池设计的可能性。
Rechargeable aqueous Zn–MnO2technology combines one of the oldest battery chemistries with favourable sustainability characteristics, including safety, cost and environmental compatibility. However, the ambiguous charge storage mechanism presents a challenge to fulfil the great potential of this energy technology. Here we leverage on advanced electron microscopy, electrochemical analysis and theoretical calculations to look into the intercalation chemistry within the cathode material, or α-MnO2more specifically. We show that Zn2+insertion into the cathode is unlikely in the aqueous system; rather, the charge storage process is dominated by proton intercalation to form α-HxMnO2. We further reveal anisotropic lattice change as a result of entering protons proceeding from the surface into the bulk of α-MnO2, which accounts for the structural failure and capacity decay of the electrode upon cycling. Our work not only advances the fundamental understanding of rechargeable zinc batteries but also suggests the possibility to optimize proton intercalation kinetics for better-performing cell designs.