摘要
锂金属具有氧化还原电位低、理论比容量大等优点,是下一代高比能电池极具发展前景的负极.然而,锂枝晶生长和低可逆性严重阻碍了高比能锂金属电池的发展.受启发于生物细胞膜结构,本文采用涂布法在锂金属表面成功构筑了一种具有仿生离子通道的人工界面固体电解质层(CAL).该CAL中大量带负电荷的离子通道可以促进锂离子均匀、快速的输运,有利于稳定、均匀地进行锂沉积/剥离.此外,在循环过程中,CAL底部与锂金属发生原位转化反应,生成了一层富含亲锂性无机组分的过渡层,促进了锂离子的扩散并抑制了锂金属与电解液的连续副反应.因此,形成的具有双面神结构的人工界面固体电解质层(CAJL)使得锂金属负极可以在10 mA cm^(-2)的高电流密度和10 mAh cm^(-2)的高面积容量下长期稳定循环.更重要的是,基于CAJL功能化锂金属负极的锂硫软包电池实现了429.2 Wh kg^(-1)的高能量密度.
Lithium(Li)metal with low electrochemical potential and high theoretical capacity is a promising anode material for next-generation batteries.However,the low reversibility and safety problems caused by the notorious dendrite growth significantly impede the development of high-energy-density lithium metal batteries(LMBs).Here,to enable a dendrite-free and highly reversible Li metal anode(LMA),we develop a cytomembrane-inspired artificial layer(CAL)with biomimetic ionic channels using a scalable spread coating method.The negatively charged CAL with uniform intraparticle and interparticle ionic channels facilitates the Li-ion transport and redistributes the Li-ion flux,contributing to stable and homogeneous Li stripping and plating.Furthermore,a robust underneath transition layer with abundant lithiophilic inorganic components is in-situ formed through the transformation of CAL during cycling,which promotes Li-ion diffusion and suppresses the continuous side reactions with the electrolyte.Additionally,the resulting cytomembrane-inspired artificial Janus layer(CAJL)displays an ultrahigh Young's modulus(≥10.7 GPa)to inhibit the dendrite growth.Consequently,the CAJL-protected LMA(Li@CAJL)is stably cycled with a high areal capacity of 10 mAh cm~(-2)at a high current density of 10 mA cm~(-2).More importantly,the effective CAJL modification realizes the stable operation of a practical 429.2 Wh kg~(-1)lithiumsulfur(Li-S)pouch cell using a low electrolyte/sulfur(E/S)ratio of 3μL mg~(-1).The facile yet effective protection strategy of LMAs can promote the practical application of LMBs.
作者
李一举
王天帅
陈俊杰
彭旭东
陈明辉
刘斌
慕永彪
曾林
赵天寿
Yiju Li;Tianshuai Wang;Junjie Chen;Xudong Peng;Minghui Chen;Bin Liu;Yongbiao Mu;Lin Zeng;Tianshou Zhao(Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen 518055,China;Department of Mechanical and Aerospace Engineering,The Hong Kong University of Science and Technology,Hong Kong,China;School of Chemistry and Chemical Engineering,Northwestern Polytechnical University,Xi’an 710129,China)
基金
financially supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(T23-601/17-R)
supported by the Fundamental Research Funds for the Central Universities(D5000220443)。
