Fluoroethylene Carbonate Additives to Render Uniform Li Deposits in Lithium Metal Batteries
Fluoroethylene Carbonate Additives to Render Uniform Li Deposits in Lithium Metal Batteries
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DOI：
10.1002/adfm.201605989
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发表时间：
2017-03
影响因子：
19
通讯作者：
Xue‐Qiang Zhang;Xin‐Bing Cheng;Xiang Chen;Chong Yan;Qiang Zhang
中科院分区：
文献类型：
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作者：
Xue‐Qiang Zhang;Xin‐Bing Cheng;Xiang Chen;Chong Yan;Qiang Zhang
锂（Li）金属被认为是石墨阳极的重要替代品，以进一步提高锂离子电池的能量密度。然而，在Li镀覆/剥离期间的Li枝晶生长引起安全问题和Li金属电池（LMB）的寿命差。在本文中，氟代碳酸亚乙酯（FEC）添加剂用于形成富含LiF的固体电解质中间相（SEI）。FEC诱导的SEI层是致密且稳定的，因此有利于获得Li沉积物的均匀形态。这种均匀且无枝晶的形态使得在100次循环内，Li|铜半电池当FEC保护的Li金属阳极匹配高负载LiNi0.5Co0.2Mn0.3O2（NMC）阴极（12 mg cm−2）时，在180.0 mA g−1下获得154 mAh g−1（1.9 mAh cm−2）的高初始容量。这种具有转换型Li金属阳极和嵌入型NMC阴极的LMB提供了一种新兴的储能系统，以探索Li金属保护的能量化学，并展示了具有非常高能量密度的电池的材料工程。
Lithium (Li) metal has been considered as an important substitute for the graphite anode to further boost the energy density of Li‐ion batteries. However, Li dendrite growth during Li plating/stripping causes safety concern and poor lifespan of Li metal batteries (LMB). Herein, fluoroethylene carbonate (FEC) additives are used to form a LiF‐rich solid electrolyte interphase (SEI). The FEC‐induced SEI layer is compact and stable, and thus beneficial to obtain a uniform morphology of Li deposits. This uniform and dendrite‐free morphology renders a significantly improved Coulombic efficiency of 98% within 100 cycles in a Li | Cu half‐cell. When the FEC‐protected Li metal anode matches a high‐loading LiNi0.5Co0.2Mn0.3O2 (NMC) cathode (12 mg cm−2), a high initial capacity of 154 mAh g−1 (1.9 mAh cm−2) at 180.0 mA g−1 is obtained. This LMB with conversion‐type Li metal anode and intercalation‐type NMC cathode affords an emerging energy storage system to probe the energy chemistry of Li metal protection and demonstrates the material engineering of batteries with very high energy density.