微通道内锂电极浆料流动-电化学反应协同机制研究

锂浆料液流电池是以锂离子电极活性固体颗粒和导电颗粒分散在电解液中的悬浮液作为电极的一种革新性液流电池，结合了锂离子电池和液流电池两者的优点，是有巨大潜力的大规模储能应用的可选择技术之一。本项目针对高粘度、高颗粒浓度液固两相流非牛顿流体悬浮液浆料在反应器微通道内的流动行为与电化学反应的匹配性问题，从“三传一反”的化工角度出发，通过流场实验观测与原位电化学测试，并结合流场-电化学耦合模拟方法，研究锂浆料液流电池反应器微通道内悬浮液浆料的速度场演变，固相颗粒的富集与分离规律，集流体和隔膜表面粗糙度、润湿性等界面特性对流场的影响；研究流体速度场、颗粒浓度分布对电化学反应程度与均匀性的影响，揭示反应器结构-流动-电化学性能之间的耦合规律。从而提出适合的浆料流变特性，以及电池最佳操作条件，同时优化设计反应器微通道结构与界面。进一步制备容量>50Ah锂浆料液流电池单体，能量密度>80Wh/kg。

Lithium slurry flow battery is a kind of innovative liquid flow battery, which takes the suspension of active solid particles and conductive particles dispersed in the electrolyte as the electrode. It combines the advantages of lithium ion battery and liquid flow battery, and is one of the optional technologies with great potential for large-scale energy storage applications. However, the Lithium slurry flow battery is confronted with some complex problems such as the coordination between flow behavior and electrochemical reaction for high viscosity, high particle concentration and non-Newtonian fluid electrode in the mm-scale microchannel. In response to this problem, base on the chemical engineering perspective of "Three Transfers and One Reaction", experimental observation of electrode flow and in-situ electrochemical measurement, combined with simulation method of flow field and electrochemical reaction, are adopted in the project. Thus, the velocity field evolution of suspension slurry in the microchannel of lithium slurry flow battery reactor, the enrichment or segregation of solid particles, and the influence of interface characteristics such as roughness and wettability of current collector or separator surface on the flow field are studied. Moreover, the effects of slurry velocity field and particle concentration distribution on the degree and uniformity of electrochemical reaction are analyzed, and the coupling relationships among battery reactor structure, slurry flow, electrochemical performance are revealed. The purposes of this project are to propose suitable rheological properties of the slurry and the optimal operating conditions of the battery, and to optimize the structure and interface of the reactor microchannel. Furthermore, the lithium slurry flow cell with capacity > 50Ah is prepared with energy density > 80wh/kg.