集流体/活性材料一体化Sn基纳米多孔电极的原位制备及其储锂性能研究

For the current issues of surface contamination of current collector and severe electrode polarization easily caused during deposition process of active material on nanoporous copper current collector with high surface energy, this project is on the basis of analyzing the domestic and international research results and previous research, and proposes to develop the in-situ preparation of three-dimensional nanoporous electrode with current collector/active material integration using dealloying technique, and would mainly investigate the in-situ preparation process and mechanism of integrated tin-based nanoporous electrode, understand the corrosion or/and passivation behaviors during preparation process and corresponding porous structure evolution process, solve the key issues of shaping uniformity and structure controllability of porous electrode, clarify the chemical/electrochemical influence factors of their morphology, pore size, component. Furthermore, this project would investigate the influence of doping inert elements of other species in precursor alloys and electrode postprocessing means on porous electrode strengthening, revealing its strengthening mechanism. Based on it, the integrated porous electrode would be used as the anode for lithium ion battery, and this project also would investigate its electrochemical behaviors, like specific capacity, cycle life, high rate capability etc., through various electrochemical characterization methods, reveal the influence of chemical composition and microstructure of active material as well as electrode strengthening on their electrochemical properties, understand the reaction and migration mechanism of lithium-ion intercalating into and being deintercalated from the 3D porous electrode, and lastly establish the theory model suitable for electrochemical reaction process of the integrated nanoporous electrode. The implementation of this project would provide new idea and new way for design of electrode structure and preparation of electrode materials for high-performance lithium ion battery.

针对目前在高表面能的纳米多孔铜集流体材料上负载活性物质时易导致集流体表面污染、电极极化严重的问题，本项目在总结分析国内外研究成果及前期研究的基础上，提出利用去合金化技术原位制备集流体/活性材料一体化的三维纳米多孔电极，重点研究一体化锡基纳米多孔电极的原位制备过程与机理，认识制备过程中的腐蚀/钝化行为与对应孔结构演化，解决多孔电极的成形均匀性与结构可控性，阐明影响其形貌、孔径、成分的化学/电化学因素；探索前驱体合金中掺杂第二类惰性元素及电极后处理手段对多孔电极强化的影响，揭示其强化机理；在此基础上，应用于锂离子电池，利用多种电化学表征手段，研究其比容量、循环寿命、快速充放电等电化学行为，揭示活性材料化学组成、微观形貌及电极强化对其性能的影响规律，认识锂离子嵌脱反应与迁移机制，建立适用于一体化纳米多孔电极电化学反应过程的理论模型，为高性能锂离子电池电极结构设计和电极材料制备提供新思路和新方法。

随着现代工业的快速发展，化石能源的过度消耗与环境污染已成为当今焦点问题。锂离子电池作为新型可再生能源储存器件，因能量密度高、循环寿命长、环境友好、可再生使用等优点，被认为可有效应对上述挑战。但由于传统二维平面电极无法有效缓冲高理论容量负极材料充放电过程中的体积和结构变化，新型三维结构电极设计势在必行。针对目前在高表面能的纳米多孔集流体上负载活性物质时易导致其表面污染、电极极化严重的问题，本项目基于不同含锡前驱体合金，巧妙利用去合金化技术原位制备出多种集流体/活性材料一体化的锡基纳米多孔电极，重点研究了其制备过程与机理，认识了制备过程中的腐蚀/钝化行为与孔结构演化，阐明了影响其形貌、孔径、成分的化学/电化学因素；探明了前驱体合金中掺杂第二类惰性元素及电极后处理手段对多孔电极强化的影响，揭示了强化机理；在此基础上，应用于锂离子电池，利用多种电化学表征手段，研究了比容量、循环寿命、快速充放电等电化学行为，揭示了活性材料化学组成、微观形貌及电极强化对性能的影响规律，认识了锂离子嵌脱反应与迁移机制，获得了优良的电极结构与电池性能，为高性能锂离子电池电极结构设计和电极材料制备提供了新思路和新方法。