基于多物理场耦合的新型氮氧自由基有机正极设计、制备及储锂机制研究

The pressure-resistant lithium-ion battery is one of the main forms of power use in the deep sea environment as an Autonomous Underwater Vehicle (AUV) in the future, which can enhance its ability to perform tasks in a diversified environment in the deep sea. The existing pressure-resistant lithium-ion battery is developing slowly, mainly because the electrode material such as the cathode material is lacking in the performance mechanism of the multi-physics coupling environment such as deep sea high pressure and low temperature, and it is impossible to provide theoretical guidance. Nitrogen-oxygen free radicals have advantages such as stable electrochemical activity and high electron transport rate, which can be compared with inorganic positive electrode materials such as lithium iron phosphate, which provides a new idea for improving the performance of pressure-resistant lithium batteries. This project intends to use nitrogen-oxygen radical polymer as research object, adopt multi-physics coupling experimental platform and simulation to study its lithium storage characteristics, and design and construct high specific capacity and high rate discharge performance by means of interface engineering and chemical grafting. The "polymer-like" three-dimensional structure of nitroxide organic positive electrode; testing its electrochemical properties and revealing the structural changes and electrochemical reaction mechanism of the three-dimensional structure of the nitroxene positive electrode under the coupling of multiple physics. Through the research of this project, it provides theoretical guidance and technical support for the improvement of the performance of pressure-resistant lithium-ion battery for AUV.

耐压型锂离子电池作为水下航行器（Autonomous Underwater Vehicle，AUV）未来在深海环境下使用电源主要形式之一，可提升其在深海多元化环境中执行任务的能力。目前耐压型锂离子电池发展缓慢，主要是正极材料等电极材料在深海高压，低温等多物理场耦合环境下性能机理研究匮乏，无法为其提供理论指导。有氮氧自由基正极因其电化学活性稳定和电子传输率高等优点可媲美磷酸铁锂等无机正极材料，为提升耐压型锂电池性能提供了新思路。本项目拟通过氮氧自由基聚合物为研究对象，采用多物理场耦合实验平台和仿真模拟研究其储锂特性，利用界面工程和化学嫁接等手段设计并构筑具有高比容量和高倍率放电性能的“类聚合物”三维结构氮氧自由基有机正极；测试其电化学性能并揭示三维结构氮氧自由基正极在多物理场耦合作用下的结构变化和电化学反应机理。通过本项目的研究，为AUV用耐压型锂离子电池性能的提升提供理论指导和技术支撑。

耐压型锂离子电池作为水下航行器（Autonomous Underwater Vehicle，AUV）未来在深海环境下使用电源主要形式之一，可提升其在深海多元化环境中执行任务的能力。目前耐压型锂离子电池发展缓慢，主要是正极材料等电极材料在深海高压，低温等多物理场耦合环境下性能机理研究匮乏，无法为其提供理论指导。有氮氧自由基正极因其电化学活性稳定和电子传输率高等优点可媲美磷酸铁锂等无机正极材料，为提升耐压型锂电池性能提供了新思路。本项目通过氮氧自由基聚合物为研究对象，采用多物理场耦合实验平台和仿真模拟研究其储锂特性，利用界面工程和化学嫁接等手段设计并构筑具有高比容量和高倍率放电性能的“类聚合物”三维结构氮氧自由基有机正极；测试其电化学性能并揭示三维结构氮氧自由基正极在多物理场耦合作用下的结构变化和电化学反应机理。取得了基于石墨烯-碳纳米管、中空碳球等碳基材料的高比能高功率氮氧自由基有机正极材料，倍率性能在20C放电下，容量达到了1C放电下容量95%以上，对其作为承压电池的性能进行了验证，5000m模拟测试条件下，放电倍率达到了25C，体积比能量为354Wh/L，表现出了优异的放电性能，为全海深锂电池高功率输出稳定安全提供了理论支撑和技术支持。