功能化二维过渡金属硫化物构筑杂化聚合物纳米三明治及其超级电容器

Two-dimensional (2D) transition metal dichalcogenides (TMDs) are promising electrode materials for high performance supercapcacitors due to their unique physical, chemical, and electrochemical properties. However, most of the TMDs show poor electronic conductivity and solvent processability as well as high tendency for reaggregation and stack together. This inevitable reaggregation and stacking significantly decreases the electrochemically active surface area, thus resulting in a deteriorated supercapacitor performance. The covalent functionalization of TMDs can further enhance the versatility of 2D TMDs. In this project, we propose to functionalize TMDs with conductive polymers and porous polymers to generate TMDs-based hybrid polymer sandwiches, which integrate the advantages of TMDs, conductive polymers, and porous polymers to improve the performances of supercapacitors. 2D structure of TMDs allows for the growth of uniform polymer shells onto both sides. Thereby, the aggregation and restacking of the TMDs sheets can be effectively suppressed. The conductivity of the TMDs-based hybrid polymer sandwiches can be increased by taking the advantage of the high electrical conductivity of conductive polymers. Meanwhile, the polymer shells will endow TMDs-based hybrid polymer sandwiches with pseudocapacitance to improve capacitance and cycling stability. The porous structure and pore parameters of porous polymers can be tailored owing to the wide-ranging flexibility in the choice and design of building blocks. The microstructure, specific surface area and pore size distribution of TMDs-based hybrid polymer sandwiches can be tailored at molecular scale by turning the building blocks. Thereby, various TMDs-based hybrid polymer sandwiches with different supercapacitor performance can be obtained. In order to get supercapacitors with high capacitance, energy density and cycling stability, the relationship between the capacitance and the microstructure, specific surface area, and pore size distribution of TMDs-based hybrid polymer sandwiches will be investigated. The energy storage mechanism of TMDs-based hybrid polymer sandwiches, and the synergistic effect between 2D TMDs, conductive polymer networks, and porous polymers will also be investigated.

二维过渡金属硫化物得益于其独特的物化性质和优异的电化学性能等，有望作为高性能超级电容器电极材料。然而，大部分过渡金属硫化物导电性能和溶液加工性较差，易发生不可逆的聚集和堆叠，严重降低其比表面积和电容性能及循环稳定性。功能化过渡金属硫化物制备功能性复合材料可实现其在相关应用中性能的进一步提升。本项目拟采用导电聚合物和多孔聚合物对二维过渡金属硫化物进行功能化，抑制金属硫化物纳米片的聚集，制备集导电聚合物、多孔聚合物和二维过渡金属硫化物优点于一体的过渡金属硫化物基聚合物杂化三明治材料来提高超级电容器的性能。通过改变功能性有机分子构筑单元，实现在分子尺度上、不同维度上对过渡金属硫化物基聚合物杂化三明治材料微观形貌、比表面积、多孔结构和组成的精确调控，提高复合材料的电容性能和循环稳定性。探讨过渡金属硫化物、导电聚合物和多孔聚合物三者之间的协同效应与超级电容器性能之间的关系，以得到高性能的超级电容器。

采用聚合物对金属硫化物进行功能化，有效提高过渡金属硫化物的稳定性和比容量，在超级电容器器件中能有效提高器件的循环稳定性和能量密度及其倍率性能。这种聚合物功能化硫化物提高其电化学性能的方法具有普适性，可应用于其它二维材料，如MXene等。聚合功能化MXene对比没有功能化的MXene材料，稳定性和电化学性能得到显著提高。此外，采用高导电碳材料和过渡金属硫化物复合，可以显著提高过渡金属化合物基赝电容材料的导电性、比容量和倍率性能。通过电极材料的选取，调控正负电极的匹配性，可有效提高过渡金属化合物基水系非对称超级的电容器的电压窗口和能量密度。该项目执行期间在J. Am. Chem. Soc.; Adv. Funct. Mater.; ACS Nano; Sci. China Mater.等国际权威刊物上相继发表论文20余篇，其中影响因子大于10的论文15篇。被Chem. Rev., Chem. Soc. Rev., Nat. Energy, Nat. Commun., J. Am. Chem. Soc., Adv. Mater., Angew. Chem. Int. Ed.等国际知名期刊引用和详细点评。其中J. Am. Chem. Soc. 2020被入选中国百篇最具影响国际学术论文和ESI热点论文，ACS Energy Lett. 2018, ACS Nano 2018，J. Am. Chem. Soc. 2020三篇论文入选ESI高被引论文；J. Am. Chem. Soc. 2020 和Small 2020 两篇文章被选为封面文章。在超级电容器电极材料、电解液、器件结构等方面申请系列发明专利，获授权发明专利5项；副主编教材一部，撰写英文著作一章；作为主要完成人获教育部自然科学奖二等奖1项（排名第五），获省级教学成果奖二等奖（排名第三）。