高比能锂离子电容器掺杂碳正极材料的设计、制备及性能改善机理研究

Lithium ion capacitors (LICs) have been proposed to be one of the promising new energy storage devices candidates to bridge the gap between LIBs and SCs, possessing high energy and power density. The current activated carbon cathode material for LICs has low specific capacity and poor resistance to high work voltage, which need to be improved in order to meet the demand for large-scale energy storage. Our previous research has shown that nitrogen doping can increase the specific capacity of porous carbon cathode materials with high specific surface area. This project will adopt the strategy of design of the pores and doping to increase the adsorption sites (and/or pseudocapacitance) and enlarge the carbon interlayer distance by regulating the amount of dopant and optimizing the pore size and distribution. High-voltage heteroatom doped carbon cathode materials with high specific capacities are expected to be prepared. Different (in-situ) characterization methods will be applied to investigate the mechanism of doping type, doping content and pore structure (or specific surface area) in improving the specific energy density and high-voltage endurance for the carbon based materials. The intrinsic relationship among doping, pore structure and energy density of carbon based cathodes is expected to be figured out. A new strategy is to be developed to efficiently produce high performance carbon based cathode materials. The influence of electrode composition and the design of the gradient structure on the transmission of ions and electrons will be studied to obtain the key technology for the preparation of high performance electrodes. The research results will provide theoretical guidance and technical support for the design and preparation of high-performance cathode materials and electrodes for high energy and power density LICs.

锂离子电容器（LICs）是一种兼具电池高能量密度和电容器高功率特性的新型储能器件。现用的LICs活性炭正极材料存在比容量较低及耐高压性能较差等问题，亟待制备新型高性能正极材料及其电极。本项目基于课题组前期研究基础（氮掺杂可以增加多孔碳正极材料的比容量），拟采用孔设计和掺杂来增加吸附位点（和/或赝电容）及扩张碳层间距的策略，精细调节掺杂量和优化孔结构，构建具有高比容量和耐高压性能的杂原子掺杂碳基正极材料。利用多种（原位）表征技术研究原子掺杂和孔结构（或有效比表面积）在提高比容量和耐高压性能方面协同提高能量密度的作用机制，有望获得原子掺杂和孔结构与材料比能量密度之间的内在构效关系，并建立高效制备高性能碳基正极材料的新方法。研究电极的组成和梯度结构设计对其离子和电子传输的影响规律，进而获得制备高性能电极的关键技术。本项目研究成果为高性能LICs正极材料及其电极的设计和制备提供理论指导和技术支撑。

锂离子电容器（LICs）是一种兼具高能量密度和高功率特性的储能器件。针对商业活性炭比容量较低及耐高压性能较差，正、负极材料动力学性能难以匹配，以及环境友好的高效率制备高性能多孔碳材料路线缺乏等问题，本项目基于杂原子掺杂提升多孔碳材料比容量的新策略，开展了以下几个方面的研究工作。1）开发了几种新型低共熔溶剂并将其作为活化剂和杂原子掺杂剂，发展了几条高效率制备了杂原子掺杂多孔碳（HDPCs）材料的新型环保路线；2）通过精细调控杂原子掺杂量达到碳层晶面间距扩张并增加赝电容以及优化孔结构提升倍率性能和体积比能量的协同策略，构建了具有高比容量和耐高压性能（~4.5 V）的HDPCs正极材料；3）结合复合导电剂提升HDPCs基材料在真实电极中的性能发挥策略，并匹配自开发的高性能HDPCs基负极材料，优化预嵌锂技术和正、负极的比例，组装了高比能和循环性能优异的LICs；4）研究了不同HDPCs材料在不同电解液中的性能，揭示了电解液的成分（溶剂和锂盐）与材料的匹配性相关规律。相关研究成果为高性能LICs正、负极材料及其复合电极提供理论指导和技术支撑。. 在项目资助下，发表相关论文20篇（其中12篇标注为第一资助），申请发明专利5 件（已授权1 件）；培养博士生1 名，硕士6名；项目负责人以邀请报告的方式参加学术会议3 次，经费使用合理，较好地完成了项目的既定目标。