Influence of CsNO_3 as electrolyte additive on electrochemical property of lithium anode in rechargeable battery  

电解液添加剂CsNO_3对锂金属负极电化学性能的影响（英文）

作　　者：LIN Hua CHEN Kang-hua SHUAI Yi HE Xuan GE Ke 林华;陈康华;帅毅;何璇;葛科

机构地区：[1]State Key Laboratory of Powder Metallurgy, Central South University [2]Light Alloy Research Institute, Central South University

出　　处：《Journal of Central South University》2018年第4期719-728,共10页中南大学学报（英文版）

基　　金：Project(2016YFB0300801)supported by the National Key Research and Development Program of China;Project(2012CB619502)supported by the National Basic Research Program of China

摘　　要：Lithium metal is one of the most promising anode materials for rechargeable battery with high energy density,but its practical use is still hindered by two main problems,namely,lithium dendrite growth and low Coulombic efficiency.To address the issues,cesium nitrate(CsNO3)is selected as the additive to modify the electrolyte for lithium secondary battery.Here we report electrochemical performance of lithium secondary battery with different concentration of CsNO3 as electrolyte additive.The study result demonstrates that Coulombic efficiency of Li–Cu cells and the lifetime of symmetric lithium cells contained CsNO3 additive are improved greatly.Li–Cu cell with 0.05 mol/L CsNO3 and 0.15 mol/L LiNO3 as electrolyte additive presents the best electrochemical performance,having the highest Coulombic efficiency of around 97%and the lowest interfacial resistance.With increasing the concentration of CsNO3 as electrolyte additive,the electrochemical performance of cells becomes poor.Meanwhile,the morphology of lithium deposited films with CsNO3-modified electrolyte become smoother and more uniform compared with the basic electrolyte.锂金属因具有高理论能量密度而成为理想的电池负极材料之一,但其在实际应用过程中主要存在两个问题:锂枝晶的生长和低库伦效率。为解决这一问题,硝酸铯(CsNO_3)被选为添加剂加入电池电解液中,研究含不同浓度CsNO_3的电解液对锂二次电池电化学性能的影响。研究结果表明,电解液中添加CsNO_3后Li–Cu电池的库伦效率得到显著提高,循环寿命得到延长。当电解液中含0.05 mol/L CsNO_3和0.15 mol/L Li NO3时,Li–Cu电池具有最佳的电化学性能,库伦效率高达97%,并具有最低的界面阻抗。随着电解液中CsNO_3浓度的提高,电池的电化学性能逐渐下降。此外,锂的沉积形貌在含CsNO_3电解液中比在无添加剂电解液中更为圆润、均匀。

关 键 词：cesium nitrate lithium anode electrolyte additive Coulombic efficiency electrochemical properties MORPHOLOGY 

分 类 号：TG146.26[一般工业技术—材料科学与工程] TM912[金属学及工艺—金属材料]