金属铋纳米颗粒原位修饰碳纳米管促进锂均匀沉积  

In-situ Modification of Carbon Nanotubes with Metallic Bismuth Nanoparticles for Uniform Lithium Deposition

作　　者：蔡佳 黄高旭 金晓盼 魏驰 毛嘉毅 李永生[1] CAI Jia;HUANG Gaoxu;JIN Xiaopan;WEI Chi;MAO Jiayi;LI Yongsheng(School of Materials Science and Engineering,East China University of Science&Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学材料科学与工程学院,上海200237

出　　处：《无机材料学报》2022年第12期1337-1343,共7页Journal of Inorganic Materials

基　　金：国家自然科学基金(51672083)。

摘　　要：锂金属具有高理论比容量和低电化学电位,是发展高能量密度电池最有吸引力的负极材料之一。然而,锂金属负极在反复的沉积/剥离过程中,不可避免地会出现不规则的锂枝晶生长,这将严重影响锂金属电池的循环寿命和使用安全性。本研究发展了一种简单温和的策略,在碳纳米管上原位修饰铋纳米颗粒,并涂覆在商业铜箔表面用作锂金属负极的集流体。研究表明,原位修饰的铋纳米颗粒可显著促进锂均匀沉积,抑制锂枝晶生长,从而提高锂金属电池的电化学性能。在电流密度为1 mA·cm^(-2)的条件下,基于Bi@CNT/Cu集流体的锂铜电池循环300圈后库仑效率可稳定在98%。基于Li@Bi@CNT/Cu负极的对称电池可稳定循环1000 h。基于Bi@CNT/Cu集流体的磷酸铁锂(LFP)全电池也获得了优异的电化学性能,在1C(170m A·g^(-1))倍率下可稳定循环700圈。本研究为抑制锂金属负极枝晶生长提供了新的思路。Lithium(Li) metal is one of the most attractive anode materials for the development of high energy density batteries due to its high theoretical specific capacity and low electrochemical potential. However, during the repeated deposition/stripping of Li metal anode, irregular Li dendrite growth inevitably takes place, which seriously affects the cycle life and safety of Li metal batteries. In this study, a simple and mild strategy was developed to in-situ modify the carbon nanotubes with bismuth(Bi) nanoparticles, followed by coating the as-prepared materials on the surface of commercial copper foil as current collector for Li metal anode. It is demonstrated that the in-situ modified Bi nanoparticles promotes the uniform Li deposition, thereby inhibiting the growth of Li dendrites and improving the electrochemical performance of Li metal batteries. Under the current density of 1 mA·cm^(-2), Coulombic efficiency of Li|Cu cell based on the Bi@CNT/Cu current collector maintains 98% after 300 cycles. Meanwhile, the symmetric cell based on the Li@Bi@CNT/Cu anode can maintain the stable cycling for 1000 h. When it is applied in LiFePO4(LFP)full cell, the Bi@CNT/Cu current collector also exhibits excellent electrochemical performance, which can retain the stable cycling for 700 cycles at the rate of 1C(170 m A·g^(-1)). This study provides a new strategy for suppressing dendrite growth of Li metal anodes.

关 键 词：锂金属电池 锂枝晶 铋纳米颗粒 集流体 

分 类 号：O646[理学—物理化学]