过渡金属氧化物-多孔氮杂碳阵列电极的可控制备及其在锂-氧电池中的应用

Lithium-oxygen battery has been considered as new generation power sources for automotive applications due to its high theoretical energy density and green nature. The development of new air electrode with efficient electro-catalytic activity toward oxygen reduction reaction and oxygen evolution reaction as well as the suitable is the key issue for the improvement of practical energy density and cyclic stability of lithium-oxygen batteries. In this proposal, we design a new type of highly ordered air electrode consisting of transition metal oxide nanoparticles decorated porous nitrogen doped carbon materials which are formed by carbonization of grafted poly(ionic liquid)s onto titanate nanotube arrays, followed by in situ formation of transition metal oxide nanoparticles at the surface of nitrogen doped carbon. The potential application of the formed air electrode will also be evaluated in an assembled lithium-oxygen battery. Through the understanding of electro-catalytic mechanism and the effect of electrode structure on cyclic stability, we hope to provide a new idea and theoretical support on the design of ordered carbon materials based air electrode for practical applications. In addition, the designed electrode structure is also applicable to re-generative fuel cells.

锂-氧电池因其高理论能量密度、清洁环保而成为新一代动力电池的重要发展方向。开发高效的空气电极双功能催化剂和设计特殊的空气阴极结构是提升电池实际能量密度和循环稳定性的关键。本项目拟采用原位引发聚合技术将咪唑类离子液体接枝到无机二氧化钛纳米管阵列内，并以接枝的聚离子液体为前驱体，制备氮原子掺杂的多孔碳基阵列材料；通过与过渡金属氧化物的原位耦合，制备具有氧还原/氧析出双功能的催化材料并探索其在锂-氧电池中的应用前景；通过对所设计制备的材料的氧还原/氧析出催化机理以及电极结构对循环稳定性的影响的认识，为有序化碳基电催化材料的设计和制备提供相应的技术和理论支撑。同时，本项目所提出的设计思想也可以为可再生燃料电池的电极体系的设计提供一定的借鉴。

设计和开发具有高效电催化氧还原和氧析出反应的双功能催化剂对于氧参与反应的电化学能量转换和储存器件的发展和应用至关重要。本项目采用表面引发原子转移自由基聚合反应，制备了不同杂原子分布的碳基模型催化剂，探索了杂化碳材料催化氧参与的电化学反应的活性位点及其影响因素，明确了碳原子是催化活性中心，且在吡啶氮周围以“之”字形分布的2纳米以内的碳原子均具有催化活性。分别以表面接枝聚合物和交联聚合物网络结构为前驱体，制备了具有有序结构的多孔杂化碳基材料；通过杂化碳材料的杂原子与过渡金属原子的配位，在溶剂热条件下可以实现过渡金属氧化物纳米离子在杂化碳材料上的均匀分布，所制备的复合材料表现出了了优异的双功能催化性能；实现了将所制备的杂化复合材料作为电极材料在锂系电池（锂-空气、锂-硫、锂离子）、金属-空气电池、和超级电容器中的应用，所组装的电化学能量转换和储存器件表现出了较好的充放电性能和循环性能。此外，根据所制备的材料的特性，拓展了表面接枝功能聚合物在二氧化碳吸附和化学转化领域的应用。