Solid Polymer Electrolytes with Enhanced Electrochemical Stability for High‐Capacity Aluminum Batteries
Solid Polymer Electrolytes with Enhanced Electrochemical Stability for High‐Capacity Aluminum Batteries
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用于高容量铝电池的具有增强电化学稳定性的固体聚合物电解质
DOI：
10.1002/aenm.202303285
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发表时间：
2024-01
影响因子：
27.8
通讯作者：
O. Leung;Leo W. Gordon;R. Messinger;T. Prodromakis;Julian A. Wharton;C. Ponce de León;Theresa Schoetz
中科院分区：
文献类型：
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作者：
O. Leung;Leo W. Gordon;R. Messinger;T. Prodromakis;Julian A. Wharton;C. Ponce de León;Theresa Schoetz
氯铝酸盐离子液体是可再充电铝电池中常用的电解质，这是由于它们在室温下可逆地电沉积铝的能力。铝电池的发展目前受到这些离子液体有限的电化学稳定性、腐蚀性和湿度敏感性的阻碍。在这里，开发了基于1-乙基-3-甲基咪唑鎓氯化物-氯化铝、聚环氧乙烷和气相二氧化硅的固体聚合物电解质，其表现出相对于离子液体的增加的电化学稳定性，同时保持了13 mS cm-1的高离子电导率。在铝-石墨电池中，固体聚合物电解质可以充电到2.8 V，在66 mA g−1时达到194 mA h g− 1的最大比容量。在2.7 V下的长期循环显示出在360 mA g− 1下的123 mA h g−1的可逆容量和1000次循环后的98.4%库仑效率。固态核磁共振光谱测量揭示了五配位铝物质的形成，其交联聚合物网络以使固体电解质中的高离子液体负载成为可能。这项研究为高容量铝电池的分子水平设计和理解提供了新的见解，具有扩展的电位限制。
Chloroaluminate ionic liquids are commonly used electrolytes in rechargeable aluminum batteries due to their ability to reversibly electrodeposit aluminum at room temperature. Progress in aluminum batteries is currently hindered by the limited electrochemical stability, corrosivity, and moisture sensitivity of these ionic liquids. Here, a solid polymer electrolyte based on 1‐ethyl‐3‐methylimidazolium chloride‐aluminum chloride, polyethylene oxide, and fumed silica is developed, exhibiting increased electrochemical stability over the ionic liquid while maintaining a high ionic conductivity of ≈13 mS cm−1. In aluminum–graphite cells, the solid polymer electrolytes enable charging to 2.8 V, achieving a maximum specific capacity of 194 mA h g−1 at 66 mA g−1. Long‐term cycling at 2.7 V showed a reversible capacity of 123 mA h g−1 at 360 mA g−1 and 98.4% coulombic efficiency after 1000 cycles. Solid‐state nuclear magnetic resonance spectroscopy measurements reveal the formation of five‐coordinate aluminum species that crosslink the polymer network to enable a high ionic liquid loading in the solid electrolyte. This study provides new insights into the molecular‐level design and understanding of polymer electrolytes for high‐capacity aluminum batteries with extended potential limits.