乙腈-水系混合电解液对Zn-Na_(3)V_(2)(PO_(4))_(3)电池电化学稳定性的影响  

Effect of acetonitrile-water hybrid electrolyte on electrochemical stability of Zn-Na_3V_2(PO_4)_(3) batteries

作　　者：欧林娜 刘哲轩 曹鑫鑫 梁叔全[1,2] OU Linna;LIU Zhexuan;CAO Xinxin;LIANG Shuquan(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Key Laboratory of Electronic Packaging and Advanced Functional Materials of Hunan Province,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学电子封装及先进功能材料湖南省重点实验室,长沙410083

出　　处：《中国有色金属学报》2024年第6期1848-1860,共13页The Chinese Journal of Nonferrous Metals

基　　金：湖南省青年科技人才(荷尖)项目(2022RC1078);国家自然科学基金资助项目(52002407,51932011)

摘　　要：Na_(3)V_(2)(PO_(4))_(3)正极材料具有稳定的三维框架结构、较高的工作电压和相对成熟的制备工艺,近年来也逐渐用于水系锌离子电池中。然而,二价Zn^(2+)的脱嵌和活泼的水系反应环境会加速磷酸盐晶格的破坏。本文在Zn-Na_(3)V_(2)(PO_(4))_(3)电池体系的水系电解液中加入适量的乙腈(AN),研究电解液中AN与水的比例对离子溶剂化结构和电化学行为的影响规律,并通过非原位XRD探究Na_(3)V_(2)(PO_(4))_(3)晶体结构的演变。结果表明:过少的AN会加快正极材料晶格框架的破坏,而过多的AN会减缓电极反应动力学;在含有适量AN的电解液中,Zn-Na_(3)V_(2)(PO_(4))_(3)电池不但在50 mA/g的电流密度下具有91.4 mA·h/g的较高比容量,同时在500 mA/g的电流密度下可以稳定循环1000次且无明显容量衰退。Among various cathode materials,the Na_(3)V_(2)(PO_(4))_(3),with stable framework,high operating voltage and relatively mature manufacturing,has been applied gradually in aqueous zinc-ion batteries in recent years.However,the (de)intercalation of divalent Zn^(2+)and the overly active aqueous reaction environment will accelerate the destruction of phosphate lattice.This work introduced the addition of an appropriate amount of acetonitrile(AN) to the aqueous electrolyte of the Zn-Na_(3)V_(2)(PO_(4))_(3) battery system,investigated the influence of the ratio of AN to water on the ion solvation structure and electrochemical behavior,and explored the evolution of the crystal structure of Na_(3)V_(2)(PO_(4))_(3) according by ex-situ XRD.The results indicate that too little AN will accelerate the damage of the cathode lattice framework,while too much AN will slow down the electrode reaction kinetics.In the electrolyte containing an appropriate amount of AN,the Zn-Na_(3)V_(2)(PO_(4))_(3) batteries exhibit the high specific capacity of 91.4 mA·h/g at 50 mA/g,and the satisfactory cycle stability for 1000 times at 500 mA/g without obvious decline.

关 键 词：Zn-Na_(3)V_(2)(PO_(4))_(3)电池 乙腈 有机-无机混合电解液 电化学稳定性 离子可逆脱嵌 

分 类 号：O646.54[理学—物理化学]