Porous LiF layer fabricated by a facile chemical method toward dendrite-free lithium metal anode

作     者：Yanxia Yuan Feng Wu Guanghai Chen Ying Bai Chuan Wu Yanxia Yuan;Feng Wu;Guanghai Chen;Ying Bai;Chuan Wu

作者机构：Beijing Key Laboratory of Environmental Science and EngineeringSchool of Materials Science & EngineeringBeijing Institute of TechnologyBeijing 100081China Collaborative Innovation Center of Electric Vehicles in BeijingBeijing 100081China 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2019年第28卷第10期

页      面：197-203页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：supported by the National Basic Research Program of China (Grant no. 2015CB251100) Beijing Natural Science Foundation (No. L182023) 

主　　题：Lithium metal anode Porous LiF layer Lithium dendrite Artificial SEI 

摘      要：Lithium metal is supposed to be critical material for constructing next-generation batteries due to extremely high capacity and ultralow redox potential. However, the perplexing issue of lithium dendrite growth impedes the commercial application. The initial nucleation and low Li ions diffusion rate in the electrolyte/electrode interface dominate the deposition behavior. Therefore, a uniform and flexible interface is urgently needed. Here, a facile method is proposed to prepare a thin and porous LiF-rich layer (TPL) by the in-situ reaction of small amount of ammonium hydrogen difluoride (NH4HF2) and Li metal. The deposition morphology on Li metal anode with LiF layer is significantly flat and homogeneous owning to low lateral diffusion barrier on LiF crystals and the porous structure of TPL film. Additionally, the symmetrical cells made with such TPL Li anodes show significantly stable cycling over 100 cycles at high current density of 6 mA/cm^2. The TPL Li|LiFePO4 full cells keep over 99% capacity retention after 100 cycles at 2.0 C. This approach serves as a facile and controllable way of adjusting the protective layer on Li metal.