Reece Richard, Lekakou Constantina, Smith Paul A
Centre for Engineering Materials, University of Surrey, Guildford, GU2 7XH, U.K.
ACS Appl Mater Interfaces. 2020 Jun 10;12(23):25683-25692. doi: 10.1021/acsami.9b23427. Epub 2020 May 27.
Considering the low specific capacitance of structural solid supercapacitors, which is due to the low ion diffusivity in solid electrolytes and the small specific surface area of some structural electrodes such as carbon fiber fabrics, novel structural supercapacitor designs are proposed and evaluated in this study based on supercapacitor-functional sandwich composite materials. Typical electrochemical double layer capacitors (EDLCs) are proposed with liquid organic electrolyte 1 M TEABF in PC (propylene carbonate). In the innovative sandwich structured composites, supercapacitors are embedded in the skins and integrated in the honeycomb core where the aluminum faces of the core constitute the current collectors of the supercapacitor-functional core. The sandwich composite material exhibited a flexural modulus of 5.07 GPa and a flexural strength of 413.9 MPa. The EDLCs embedded in the skins increased the skin flexural modulus and strength by 47% and 56%, respectively, for embedded lateral EDLCs, and by 91% and 106%, respectively, for embedded lateral and longitudinal EDLCs. Compared to typical EDLCs with the same electrolyte, the structural supercapacitors in this study demonstrated superior specific electrode capacitance, = 153 F g for the honeycomb supercapacitor and = 95.7 F g for the skin supercapacitor, translating to overall structural composite material performance of 0.68 Wh/m and 30.5 W/m for the supercapacitor-functional honeycomb, and 0.02 Wh/m and 5.4 W/m for the supercapacitor-functional skin.
考虑到结构固态超级电容器的比电容较低，这是由于固体电解质中离子扩散率低以及一些结构电极（如碳纤维织物）的比表面积小，本研究基于超级电容器功能夹层复合材料提出并评估了新型结构超级电容器设计。提出了典型的电化学双层电容器（EDLC），其采用在碳酸丙烯酯（PC）中的1 M四乙基铵四氟硼酸盐液体有机电解质。在创新的夹层结构复合材料中，超级电容器嵌入在表层中，并集成在蜂窝芯中，其中芯的铝面构成超级电容器功能芯的集电器。该夹层复合材料的弯曲模量为5.07 GPa，弯曲强度为413.9 MPa。对于嵌入横向EDLC的情况，嵌入表层的EDLC使表层弯曲模量和强度分别提高了47%和56%；对于嵌入横向和纵向EDLC的情况，分别提高了91%和106%。与具有相同电解质的典型EDLC相比，本研究中的结构超级电容器表现出优异的比电极电容，蜂窝超级电容器为153 F/g，表层超级电容器为95.7 F/g，这转化为超级电容器功能蜂窝的整体结构复合材料性能为~0.68 Wh/m³和30.5 W/kg，超级电容器功能表层为0.02 Wh/m³和5.4 W/kg。
