Cao Tianci, Cheng Xiaopeng, Wang Mingming, Lu Junxia, Niu Jiajia, Liu Huan, Liu Xianqiang, Zhang Yuefei
Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China.
School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China.
ACS Appl Mater Interfaces. 2023 Feb 8;15(5):6666-6675. doi: 10.1021/acsami.2c17953. Epub 2023 Jan 27.
Lithium (Li) metal is a promising candidate for next-generation anode materials with high energy densities. However, Li dissolution/deposition processes are limited at the upper surface in contact with the electrolyte, which brings a locally high current density and then results in dendritic Li growth. This restraint of the local surface reaction during cycling has not been solved by commonly used modification strategies. In this study, a three-dimensional (3D) Li conductive skeleton is activated from atomic layer deposition (ALD) coating LiPO (LPO) on the surface of the Ni foam (LPNF). Then, the skeleton is efficiently constructed in the Li metal anode by the lower-temperature Li infusion. Ionic conductor LPO layers and electronic conductor Ni fibers supply charge transport channels between the electrolyte and the internal Li. The mixed conductive network realizes holistic charge transfer, which is proved by in situ scanning electron microscopy experiments. In virtue of dispersive dissolution/deposition and optimized electrochemical kinetics brought by a Li conductive network, the composited Li electrode presents an excellent symmetric battery cycling stability (over 1200 h) and enhanced rate performances (stable cycling even at 10.0 mA cm). When matching with a LiCoO (LCO) cathode, LCO||Li@LPNF full batteries exhibit a capacity retention of 80.8% over 250 cycles. During cycling, there was no evidence of dendrite growth and the remaining Li in the composited anode showed a smooth, compact, and well-combined condition with LPNF. Through constructing a 3D Li conductive network, the composited Li metal anode breaks through the limit of the local surface reaction; this work proposes a novel insight of realizing holistic charging/discharging for the dendrite-free Li metal anode.
锂（Li）金属是具有高能量密度的下一代阳极材料的有前途的候选者。然而，锂的溶解/沉积过程在与电解质接触的上表面受到限制，这会带来局部高电流密度，进而导致锂枝晶生长。循环过程中局部表面反应的这种限制尚未通过常用的改性策略得到解决。在本研究中，通过在泡沫镍（LPNF）表面进行原子层沉积（ALD）涂覆LiPO（LPO）来激活三维（3D）锂导电骨架。然后，通过较低温度的锂注入在锂金属阳极中有效地构建该骨架。离子导体LPO层和电子导体镍纤维在电解质和内部锂之间提供电荷传输通道。混合导电网络实现了整体电荷转移，这通过原位扫描电子显微镜实验得到证明。借助锂导电网络带来的分散溶解/沉积和优化的电化学动力学，复合锂电极呈现出优异的对称电池循环稳定性（超过1200小时）和增强的倍率性能（即使在10.0 mA cm时也能稳定循环）。当与LiCoO（LCO）阴极匹配时，LCO||Li@LPNF全电池在250次循环中容量保持率为80.8%。在循环过程中，没有枝晶生长的迹象，复合阳极中剩余的锂与LPNF呈现出光滑、致密且结合良好的状态。通过构建3D锂导电网络,复合锂金属阳极突破了局部表面反应的限制；这项工作为实现无枝晶锂金属阳极的整体充电/放电提出了新的见解。
