Phenoxy Radical-Induced Formation of Dual-Layered Protection Film for High-Rate and Dendrite-Free Lithium-Metal Anodes
Phenoxy Radical-Induced Formation of Dual-Layered Protection Film for High-Rate and Dendrite-Free Lithium-Metal Anodes
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苯氧自由基诱导形成高倍率和枝晶双层保护膜自由锂金属阳极
DOI：
10.1002/anie.202110441
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发表时间：
2021-11-16
影响因子：
16.6
通讯作者：
Xiong, Xunhui
中科院分区：
文献类型：
--
作者：
Chen, Chao;Liang, Qianwen;Xiong, Xunhui
锂金属阳极的枝晶生长不可控导致循环稳定性差和安全性问题，阻碍了其在高能量密度电池中的应用。在此，苯氧基自由基Spiro-O 8由于其优异的成膜能力和显著的离子导电性而被提议作为锂金属阳极的人工保护膜。Spiro-O 8和Li金属之间的自发氧化还原反应导致在底部形成均匀且高度离子传导的有机膜。同时，Spiro-O 8表面的苯氧基自由基促进了锂盐在醚电解质中的分解，并导致在顶部形成LiF膜。由于内层高离子导电膜和外层刚性膜的协同作用，在高电流密度（10 mA cm（-2），4000次循环）和5 mAh cm（-2）的高面容量条件下，可实现稳定的Li镀/脱，镀/脱时间为550 h，锂的利用率为54.6%.作为概念证明，这项工作显示了一种简单的策略，合理地制造双层界面的锂金属阳极。
The uncontrollable dendrite growth of Li metal anode leads to poor cycle stability and safety concerns, hindering its utilization in high energy density batteries. Herein, a phenoxy radical Spiro-O8 is proposed as an artificial protection film for Li metal anode owing to its excellent film-forming capability and remarkable ionic conductivity. A spontaneous redox reaction between the Spiro-O8 and Li metal results in the formation of a uniform and highly ionic conductive organic film in the bottom. Meanwhile, the phenoxy radicals on surface of Spiro-O8 facilitate the decomposition of Li salt upon exposed to the ether electrolyte and lead the formation of LiF film on the top. Arising from the synergistic effects of inner high ionic conductive film and outer rigid film, stable Li plating/stripping can be realized at a high current density (4000 cycles at 10 mA cm(-2)) and a high areal capacity of 5 mAh cm(-2) for 550 h with an ultrahigh Li utilization rate of 54.6 %. As a proof of concept, this work shows a facile strategy to rationally fabricate dual-layered interfaces for Li metal anodes.