Nano-Micro Letters ( IF 31.6 ) Pub Date : 2021-08-09 , DOI: 10.1007/s40820-021-00687-3 Tiancun Liu 1 , Jinlong Wang 1 , Yi Xu 1 , Yifan Zhang 1 , Yong Wang 1, 2
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Highlights
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A facile method is adopted to obtain cucumber-like lithiophilic composite skeleton.
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Massive lithiophilic sites in cucumber-like lithiophilic composite skeleton can promote and guide uniform Li depositions.
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A unique model of stepwise Li deposition and stripping is determined.
Abstract
The uncontrolled formation of lithium (Li) dendrites and the unnecessary consumption of electrolyte during the Li plating/stripping process have been major obstacles in developing safe and stable Li metal batteries. Herein, we report a cucumber-like lithiophilic composite skeleton (CLCS) fabricated through a facile oxidation-immersion-reduction method. The stepwise Li deposition and stripping, determined using in situ Raman spectra during the galvanostatic Li charging/discharging process, promote the formation of a dendrite-free Li metal anode. Furthermore, numerous pyridinic N, pyrrolic N, and CuxN sites with excellent lithiophilicity work synergistically to distribute Li ions and suppress the formation of Li dendrites. Owing to these advantages, cells based on CLCS exhibit a high Coulombic efficiency of 97.3% for 700 cycles and an improved lifespan of 2000 h for symmetric cells. The full cells assembled with LiFePO4 (LFP), SeS2 cathodes and CLCS@Li anodes demonstrate high capacities of 110.1 mAh g−1 after 600 cycles at 0.2 A g−1 in CLCS@Li|LFP and 491.8 mAh g−1 after 500 cycles at 1 A g−1 in CLCS@Li|SeS2. The unique design of CLCS may accelerate the application of Li metal anodes in commercial Li metal batteries.
中文翻译：
逐步锂沉积和剥离模型实现无枝晶且稳定的锂金属电池
强调
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采用简便的方法获得黄瓜状的亲锂复合骨架。
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黄瓜状亲锂复合骨架中大量的亲锂位点可以促进和引导锂的均匀沉积。
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确定了一种独特的逐步锂沉积和剥离模型。
抽象的
在锂电镀/剥离过程中锂（Li）枝晶的不受控制的形成和不必要的电解液消耗一直是开发安全稳定的锂金属电池的主要障碍。在此，我们报告了一种通过简便的氧化-浸渍-还原方法制造的黄瓜状亲锂复合骨架（CLCS）。在恒流锂充电/放电过程中使用原位拉曼光谱确定的逐步锂沉积和剥离促进了无枝晶锂金属负极的形成。此外，许多吡啶 N、吡咯 N 和 Cu x具有优异亲锂性的 N 位点协同作用以分布锂离子并抑制锂枝晶的形成。由于这些优势，基于 CLCS 的电池在 700 次循环中表现出 97.3% 的高库仑效率，对称电池的寿命提高了 2000 小时。由 LiFePO 4 (LFP)、SeS 2正极和 CLCS@Li负极组装的全电池在 CLCS@Li|LFP 中以 0.2 A g -1循环 600 次后表现出 110.1 mAh g -1的高容量，在 CLCS@Li|LFP 中表现出 491.8 mAh g -1的高容量。在 CLCS@Li|SeS 2中以 1 A g -1循环 500 次。CLCS的独特设计可能会加速锂金属负极在商用锂金属电池中的应用。
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