基于第一性原理计算Mo_(2)NS_(2)对多硫化锂的吸附性能  

Calculation of Adsorption Properties of Mo_(2)NS_(2) for Lithium Polysulfide Based on First Principle

作　　者：彭祯凯 李卫[1,2] 任青颖 朱宸 许杰 白刚 Peng Zhenkai;Li Wei;Ren Qingying;Zhu Chen;Xu Jie;Bai Gang(College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology),Nanjing University of Posts and Telecommunications,Nanjing 210023,China;Jiangsu Province Engineering Research Center for Fabrication and Application of Special Optical Fiber Materials and Devices,Nanjing 210023,China)

机构地区：[1]南京邮电大学电子与光学工程学院、柔性电子(未来技术)学院,南京210023 [2]江苏省特种光纤材料与器件制备及应用工程研究中心,南京210023

出　　处：《微纳电子技术》2023年第5期720-728,共9页Micronanoelectronic Technology

基　　金：江苏省高等学校自然科学研究重大项目(20KJA510001);江苏省“六大人才”高峰高层次人才计划;江苏省高校青蓝工程中青年学术带头人计划项目。

摘　　要：高效的储能技术一直都是限制新能源汽车发展的关键因素,而具有超高理论比能量密度(2 500 W·h/kg)的锂硫电池被认为是最有希望的下一代可充电电池。然而,锂硫电池的实际应用受到硫导电性差和多硫化锂的穿梭效应等的限制。为了解决这些问题,提出以硫功能化的过渡金属氮化物材料来提高锂硫电池的电化学性能。对载体二硫氮化钼和吸附物多硫化锂进行建模,并计算载体的态密度;通过计算系统总能量找到了最佳吸附构型,并研究了吸附多硫化锂后复合材料的电荷差分密度和态密度;计算了多硫化锂在吸附载体界面的吉布斯自由能。研究结果表明,二硫氮化钼对多硫化物有较好的吸附强度,在放电过程中表现出较低的吉布斯自由能势垒(0.84 eV),加快了放电反应速率,缩短了电极反应中的多硫化锂的存在时间,从而有利于抑制多硫化锂的溶解和穿梭效应。本研究为过渡金属氮化物以及其他二维材料作为高性能硫阴极材料的设计提供了参考。Efficient energy storage technology has been a key factor limiting the development of new energy vehicles,and lithium-sulfur battery with an ultra-high theoretical specific energy density(2500 W·h/kg)is considered the most promising next-generation rechargeable battery.However,the practical application of lithium-sulfur batteries is limited by poor sulfur conductivity and the shuttle effect of lithium polysulfide.To solve these problems,the sulfur-functionalized transition metal nitride materials were proposed to improve the electrochemical performance of lithium-sulfur batteries.The carrier disulfide molybdenum nitride and the adsorbate lithium polysulfide were modeled,and the density of states of the carrier was calculated.The best adsorption configuration was found by calculating the total energy of the system,and the charge difference density and density of states of the composite materials after adsorbing lithium polysulfide were studied.The Gibbs free energy of lithium polysulfide at the adsorption carrier interface was calculated.The research results show that disulfide molybdenum nitride has good adsorption strength for polysulfides,exhibiting a low Gibbs free energy barrier(0.84 e V)during discharge,which speeds up the discharge reaction rate and shortens the presence time of lithium polysulfide in the electrode reaction,thus helping to suppress the dissolution and shuttle effect of lithium polysulfide.The study provides reference for the design of transition metal nitrides and other two-dimensional materials as high-performance sulfur cathode materials.

关 键 词：锂硫电池 穿梭效应 第一性原理计算 二硫氮化钼 吸附强度 

分 类 号：O614[理学—无机化学] TM912[理学—化学]