Fast Charging Limits of Ideally Stable Metal Anodes in Liquid Electrolytes
Fast Charging Limits of Ideally Stable Metal Anodes in Liquid Electrolytes
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DOI：
10.1002/aenm.202102967
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发表时间：
2021-09
影响因子：
27.8
通讯作者：
Bingyuan Ma;P. Bai
中科院分区：
文献类型：
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作者：
Bingyuan Ma;P. Bai
下一代高能量密度电池需要理想稳定的金属阳极，在电池充电过程中，光滑的金属沉积被认为是界面稳定性的标志，可以确保高效率和长循环寿命。随着近年来的研究成功，绝对的形态稳定性是否保证了绝对的电化学稳定性和安全性已成为在实际条件下进行系统实验研究的关键问题。在这里，理想稳定的铸锭型金属钠阳极被用作模型系统，以确定金属阳极的快速充电限制，即最高安全电流密度。结果表明，在相对较低的电流密度下，金属渗透仍然可以发生，但渗透处的过电位取决于隔膜的孔径，并且令人惊讶地遵循一个简单的数学模型，即Young-Laplace过电位。这项研究表明，即使是理想的光滑金属阳极，稳定的金属电池的成功也需要电解质、分离器和金属阳极的整体设计，以确保无渗透操作。
Next‐generation high‐energy‐density batteries require ideally stable metal anodes, for which smooth metal deposits during battery recharging are considered a sign of interfacial stability that can ensure high efficiency and long cycle life. With the recent successes, whether the absolute morphological stability guarantees absolute electrochemical stability and safety has emerged as a critical question to be investigated in systematic experiments under practical conditions. Here, the ideally stable ingot‐type sodium metal anode is used as a model system to identify the fast‐charging limits, that is, highest safe current density, of metal anodes. The results show that metal penetration can still occur at relatively low current densities, but the overpotentials at the penetration depend on the pore sizes of the separators and surprisingly follow a simple mathematical model developed as the Young–Laplace overpotential. This study suggests that the success of stable metal batteries with even the ideally smooth metal anode requires the holistic design of the electrolyte, separator, and metal anodes to ensure penetration‐free operation.