Designable ultra-smooth ultra-thin solid-electrolyte interphases of three alkali metal anodes

该研究是在毛秉伟教授和董全峰教授共同指导下，由2014级博士生谷宇、2016级博士生王卫伟、2013级博士生李艺娟等同学通力合作的成果。泉州师范学院吴启辉教授和上海应用物理研究所樊春海研究员分别在X射线光电子能谱表征和同步辐射表征中提供了大力支持。化学化工学院郑明森副教授、颜佳伟教授、吴德印教授、iChEM研究员丁松园博士在实验和理论计算方面给予了大力帮助；田中群教授和郑南峰教授等对此工作提出了宝贵意见。 金属锂是下一代高能量密度二次电池最理想的负极材料之一。在以金属锂作为负极的电池中，锂电沉积过程中枝晶的生长及溶解过程的死锂现象是制约电池库仑效率、稳定性和安全性的重要因素，而金属锂表面的微观平整性及固态电解质界面（SEI）膜的组成和结构及由其所决定的电学和力学性质对锂电沉积和溶解行为有重要影响。 课题组所发展的电化学调控方法可进一步拓展到钠、钾碱金属负极上，形成大范围原子平整的钠、钾表面和超薄超光滑的SEI膜。特别是金属钠平面电极可在2 mA cm–2（1 mAh cm–2）100% Na DOD下稳定循环550周以上且库伦效率近100%。这一基于电化学调控的碱金属表面抛光和SEI膜构筑的方法及多尺度联合表征，为解决碱金属负极问题提供了新的思路，也为开展表面科学基础研究提供高质量的碱金属表面。【Abstract】Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical polishing, which removes microscopic defects and creates ultra-smooth ultra-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the ultra-smooth ultra-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm-2 with 100% depth of discharge. Our work illustrates that an ultra-smooth ultra-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.This work was supported by the MOST projects (2015CB251102, 2012CB932902) and the NSFC projects (U1305246, 21621091, 21473147, 21533006, 21673193). 研究工作得到科技部973计划（项目批准号：2015CB251102、2012CB932902），国家自然科学基金（项目批准号：U1305246、21621091、21473147、21533006、21673193）等项目的资助

Application of Electrochemical Techniques to the Researches in Life Science

本文简要介绍作者近两年来采用电化学方法并结合其他现代生物、化学技术 ,在生命科学几个热点领域所开展的一些工作 ,主要包括 :蛋白质的功能转换、生物信号分子及其与蛋白质的相互作用、生物分子的电子传递、基因检测、结构生物学、生化分析与第三代生物传感器等几个方面The research work of our group in the last two years is briefly reviewed in this paper. By using electrochemical method, and combining some other chemical and biological techniques, lots of achievements have been obtained. And these researches are towards some hot topics in life science, such as function conversion, interaction between signal molecules and proteins, electron_transfer of biomolecules, gene detection, structural biology, biochemical analysis and the third generation biosensors.作者联系地址：南京大学生物化学系医药生物技术国家重点实验室,南京大学生物化学系医药生物技术国家重点实验室,南京大学生物化学系医药生物技术国家重点实验室 江苏南京210093 ,江苏南京210093 ,江苏南京210093Author's Address: Dept. of Biochem. and National Key Lab. of Pharmaceutical Biotechnology, Nanjing Univ., Nanjing 210093,Chin