面向电网储能的液态金属电池安全特性研究

It is widely recognized that grid-scale energy storage is key to continue growth of renewable energy technologies and improve efficiency and reliability of the electric grid. Liquid metal battery is a promising energy storage technology for grid application because of low cost, simple assembly and long lifespan. However, high operating temperature and highly reactive electrode materials have raised concerns about their overall safety. This proposal is focused on safety issues of liquid metal batteries. Failure mode、high temperture corrosion mechanism of secondary cell components and cell performance under extreme conditions will be investigated and the main effects on safety of liquid metal batteries will be discussed. Meanwhile, paste electrolyte will be applied to improve cell safety and the precise models for predicting state of charge (SOC) will be developed. The ultimate goal for the proposal is to understand the safety issues of liquid metal batteries and provide the basis for the application of liquid metal batteries for grid-scale energy storage.

大规模储能是消纳可再生能源发电和建设智能电网的关键技术之一。新近发展起来的液态金属电池是一类廉价高效的大型电化学储能技术，有望应用于电网的大规模储能。作为一种全液态金属高温电池，其安全特性是储能领域普遍关心的问题。本项目将围绕液态金属电池的安全特性，分别从电池失效机制、材料的高温腐蚀行为及复杂工况下的电池安全特性等三个方面对影响电池安全性的主要因素进行系统地分析和研究。在此基础上，提出通过采用膏状电解质改善电池的安全性，通过建立SOC预测模型有效监测电池安全状态，初步解决液态金属电池安全性的一些关键科学问题，为其大规模储能应用奠定基础。

项目围绕液态金属电池的安全特性，深入研究了新型锡基液态金属电池体系的微观反应机理，揭示了电池失效的主要原因。研究结果表明高熔点低密度放电产物在反应界面的不可逆累积以及关键电池材料的高温腐蚀是导致电池失效的主要原因。基于电池的反应机理和失效模型，进一步提出了提高电池安全性的改进措施和解决办法，并通过优化电池正负极集流体的材料和设计，成功构建了稳定的动态反应界面，显著提高了电池的循环稳定性。研究了热冲击下液态金属电池的安全可靠性，实验结果显示电池在反复冷却降温再升温处理后性能未见明显变化，展现了良好的耐热冲击性。同时，通过对液态金属电池的热场进行建模仿真，初步研究了电池在极端工况下（大电流、内短路、外短路等）的热效应，评估了不同工况下液态金属电池的安全可靠性。构建了液态金属电池模型，应用扩展卡尔曼滤波法实现了SOC的精确估计，为液态金属电池的可靠高效管理奠定了基础。