Lin Jialin, Huang Pei, Naren Tuoya, Liang Chaoping, Zhou Liangjun, Chen Libao, Zhang Chunxiao, Ivey Douglas G, Wei Weifeng
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, P. R. China.
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada.
Adv Mater. 2024 Sep;36(39):e2409976. doi: 10.1002/adma.202409976. Epub 2024 Aug 7.
Rechargeable sodium metal batteries are considered to be one of the most promising high energy density and cost-effective electrochemical energy storage systems. However, their practicality is constrained by the high reactivity of sodium metal anodes that readily brings about excessive accumulation of inactive Na species on the surface, either by chemical reactions with oxygen and moisture during electrode handling or through electrochemical processes with electrolytes during battery operation. Herein, this paper reports on an alkali, salt-assisted, assembly-polymerization strategy to recover Na activity and to reinforce the solid-electrolyte interphase (SEI) of sodium metal anodes. To achieve this, an alkali-reactive coupling agent 3-glycidoxypropyltrimethoxysilane (GPTMS) is applied to convert inactive Na species into Si-O-Na coordination with a self-assembly GPTMS layer that consists of inner O-Si-O networks and outer hydrophobic epoxides. As a result, the electrochemical activity of Na metal anodes can be fully recovered and the robust GPTMS-derived SEI layer ensures high capacity and long-term cycling under an ultrahigh rate of 30 C (93.1 mAh g, 94.8% after 3000 cycles). This novel process provides surface engineering clues on designing high power density and cost-effective alkaline metal batteries.
可充电钠金属电池被认为是最具前景的高能量密度且具有成本效益的电化学储能系统之一。然而，它们的实用性受到钠金属负极高反应性的限制，这种高反应性容易导致在电极处理过程中与氧气和水分发生化学反应，或者在电池运行过程中与电解质发生电化学反应，从而使表面上无活性的钠物种过度积累。在此，本文报道了一种碱辅助、盐辅助的组装聚合策略，以恢复钠的活性并增强钠金属负极的固体电解质界面（SEI）。为实现这一目标，应用了一种碱反应性偶联剂3-缩水甘油氧基丙基三甲氧基硅烷（GPTMS），通过由内部O-Si-O网络和外部疏水环氧化物组成的自组装GPTMS层，将无活性的钠物种转化为Si-O-Na配位。结果，钠金属负极的电化学活性得以完全恢复，并且由GPTMS衍生的坚固SEI层确保了在30 C的超高倍率下（93.1 mAh g，3000次循环后为94.8%）具有高容量和长期循环性能。这一新颖的过程为设计高功率密度和具有成本效益的碱金属电池提供了表面工程线索。
