基于Janus凝胶电解质的锂空气电池设计及稳定性能研究

Rechargeable Li-O2 batteries have been considered as a promising power source candidate for vehicle applications due to their impressive high theoretical energy density. However, the development of Li-O2 batteries are still in their infancy stage，how to improve the problem of the corrosion and passivation of lithium anode, enhance the safety and stability of electrolyte are the key factors to rapidly promote the practical application of Li-O2 batteries. The Janus membrane has two faces each with different properties, due to their unique structure, Janus membrane have been of great interest for researchers. In this project, the Janus membrane, which has asymmetric surface wetting property, was firstly brought into Li-O2 batteries, and we have designed a new series of Janus type gel polymer electrolyte and modified the surface properties by using the atomic layer deposition technique. By systematic studying the relationship among the Janus type gel polymer electrolyte’s physicochemical property and the Li-O2 batteries’ electrochemical performance, we try to reveal the possible change of interfacial structure, the critical stability condition of interfacial reaction, and further find the structure-activity relationship between the Janus type gel polymer electrolyte and the stability of the Li-O2 batteries. This project will help us to solve the bottlenecks of efficiency enhancement of the safety and stability of the Li-O2 batteries, it will also provide a new strategy to accelerate the commercialization of Li-O2 batteries.

锂空气电池作为一种拥有超高理论比能量密度的新型电池体系，在电动汽车领域具有良好的应用前景。目前，锂空气电池还处于发展的初期阶段，如何改善金属锂负极易腐蚀特性、提升电解质的安全稳定性是推动其实际应用的关键所在。Janus膜是指具有两面不同性质的膜材料，由于其特殊的结构使其成为膜科学的一个研究热点问题。本项目创新性地将具有非对称润湿特性的Janus膜引入到锂空气电池的研发中，设计并制备系列组成、结构可控的Janus凝胶电解质，利用原子层沉积技术对其进行表面性质调控，研究体系中各界面反应结构变化及界面稳定极限条件，揭示Janus凝胶电解质的物化性质与电池稳定性之间的构效关系，实现对锂空气电池循环稳定性快速、高效的提升。本项目的实施有助于解决目前锂空气电池安全稳定性提升所面临的瓶颈问题，为加速锂空气电池的商业化进程提供科学参考和理论依据。

由于真实空气中不仅有O2的存在，还有CO2等气体的影响，要将锂空气电池推向实际应用，也要理解CO2的作用和影响。同时，由于CO2转换电化学的巧妙利用，可充电Li-CO2电池作为一种新型的储能转换装置受到越来越多的关注。本项目将研究范围从锂空气电池拓展到锂二氧化碳电池，针对两种电池体系用高稳定Janus隔膜、高效电催化剂的可控制备和作用机理进行了深入的研究，结合密度泛函理论（DFT）计算，提出了新的催化机理及构效关系，为实现高性能Li-O2、Li-CO2电池提供了一些新的见解。已发表期刊论文10篇，出版学术专著1本，申请国内发明专利1项。