PC基电解液对Li/CrO_(x)一次电池高倍率性能的影响  

Influence of PC-based Electrolyte on High-Rate Performance in Li/CrO_(x)Primary Battery

作　　者：杨睿 李惠 孟庆飞 李文杰 吴际良 方永进 黄驰[1] 曹余良[1] Rui Yang;Hui Li;Qingfei Meng;Wenjie Li;Jiliang Wu;Yongjin Fang;Chi Huang;Yuliang Cao(College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China;Wuhan Zhongyuan Changjiang Technology Development Co.Ltd.,Wuhan 430090,China)

机构地区：[1]武汉大学化学与分子科学学院,武汉430072 [2]武汉中原长江科技发展有限公司,武汉430090

出　　处：《物理化学学报》2024年第9期62-68,共7页Acta Physico-Chimica Sinica

基　　金：国防基础科研计划(JCKY2021211B014)资助项目。

摘　　要：Li/CrO_(x)电池具有高能量密度和优异的倍率性能,成为高性能一次锂电池的研究热点。而基于发展具有宽温域和高介电常数的碳酸丙烯酯(PC)电解液体系,对于开发功率高和环境耐受性强的锂一次电池具有重要的应用价值。在本工作中,我们研究了CrO_(x)在PC基电解液中的放电行为,筛选了适配于大电流放电的电解液体系:1 mol·L^(-1)LiTFSI PC:DOL(1,3-二氧环戊烷)=1:2;并揭示了在PC基电解液中影响CrO_(x)大电流放电的规律:Li^(+)溶剂化鞘层中溶剂分子配位数以及参与配位的粒子类型,会极大地影响Li/CrO_(x)电池体系的倍率放电性能。低的配位数以及阴离子参与的溶剂化鞘层结构更加适配Li/CrO_(x)电池体系,能够实现大电流放电。这些规律的认识对于推动PC基电解液应用于大倍率Li/CrO_(x)电池体系具有重要指导意义。The Li/CrO_(x) battery has gained attention in the construction of smart cities,aerospace,and national defense and military applications due to its high energy density and excellent rate performance.Developing a Li/CrO_(x) battery with high specific capacity,high energy density,excellent magnification performance,long storage life,and low cost is a primary goal.In this pursuit,the role of the electrolyte in battery performance for Li/CrO_(x) primary batteries cannot be underestimated.However,current research on Li/CrO_(x) primary batteries has primarily focused on electrode materials,with limited attention given to the electrolyte.Propylene carbonate(PC)solvent possesses a wide temperature range for melting and boiling points(−48.8 to 242℃)and a high dielectric constant of 64.92.As a result,it is frequently used as a key component in electrolytes that operate under extreme temperatures and high rates.Nevertheless,its use in Li/CrO_(x) batteries remains limited.Developing electrolyte systems based on PC with a wide temperature range and high dielectric constant is crucial for the advancement of highpower and environmentally robust lithium primary batteries.In this study,we investigated the discharge behavior of CrO_(x) in PC-based electrolytes and identified suitable electrolyte systems for high-current discharge,specifically a 1 mol·L^(-1) LiTFSI PC:DOL(1,3-dioxolane)=1:2 ratio.We also demonstrated that the coordination number of solvent molecules in the solvation sheath layer around Li+ions and the solvated structure involved in coordination significantly influence the rate performance of Li/CrO_(x) battery systems in PC-based electrolytes.Reducing the coordination number of solvent molecules facilitates the desolvation behavior of solvated Li+,thereby enhancing the desolvation process on the material surface.Furthermore,lowering the coordination number of solvent molecules promotes the involvement of anions in the solvated sheath structure.When the coordination number of solvent molecules falls below 3,it

关 键 词：铬氧化物 电解液 溶剂化结构 碳酸丙烯酯 锂一次电池 

分 类 号：O646[理学—物理化学]