基于海藻酸“Egg-box”自组装结构的锂离子混合电容器

开发高容量碳正极与高倍率杂化负极材料，并实现两者在锂盐电解液中的有效匹配，是获得高性能锂离子混合电容器的关键。这需要在电极中实现离子孔道、活性位点与导电材质的优化复合及协同作用，为传统人工合成增置了新的难题。启迪于海藻酸捕集金属离子自组装“Egg-box”结构的机制，近期所创制的基于海藻酸的可设计、可调控的碳电极材料，显示出了广阔的储能应用前景。然而，目前该领域构效关系不清晰、结构和材质单一并且研究体系不完善，严重阻碍了在储能领域的发展和应用。基于此，本课题拟开展基于海藻酸/金属离子交联“Egg-box”纳米微晶结构的形成机理与调控、碳质转化与复合研究。通过研究，实现适用于锂盐电解液的高容量碳正极与高倍率杂化负极的高效制备与优化调控，揭示多孔结构、碳质组分、活性颗粒及表面化学等的协同储能机制，并实现电极材料在锂离子混合电容器中的组装与优化，为开发高效储能器件提供理论依据和应用基础。

The development of high capacitive carbon cathodes and high rate-performance anodes as well as the realization of their cooperative roles in Li-ion electrolytes is crucial to the achievement of highly effective Li-ion hybrid capacitors. The high performance requires the optimized assembly of ion-transport pathways, active sites and conductive textures in a single electrode, which put a new obstacle hard to resolve by traditional synthetic methods. Inspired by the unique self-assembly of alginate with multivalence cations to form “Egg-box” structures, we proposed recently a new way to fabricate carbon materials with tunable structures, which exhibited promising as electrodes of energy storage devices. However, the un-optimized pore structures and carbon textures of the obtained carbon electrodes hinder the application in energy storage. In addition, the effects of structures on electrochemistry property still remained unclarified. Thus, the project proposes to study the fabrication of high performance carbon electrode materials based on the “Egg-box” microcrystalline nanostructures crosslinked by alginate and metal multivalence cations. The project aims to (a) realize the effective fabrication and optimization of the electrode materials through the study of the crosslinking mechanism of “Egg-box” structures and its microstructural revolutions during the carbonization process, (2) clarify the cooperative effects on energy storage in Li-ion electrolytes of porous structures, carbon nanotextures, active nanoparticles and surface chemistry, and (3) optimize the assembly of cathodes and anodes in the Li-ion hybrid capacitors. The conduct of the project will provide new sights on the development of novel energy storage devices both in theoretical and experimental views.