China University of Science and Technology developed a new type of capacitor that can be used in the field of flexible electronic devices

【Chinese instrument network instrument research and development】 Recently, Professor Ma Mingming's group of professors at the School of Chemistry and Materials Science, University of Science and Technology of China, has designed a high-strength supramolecular hydrogel made of conductive polyaniline and polyvinyl alcohol through dynamic chemical bond cross-linking. As a electrode material, a flexible all-solid supercapacitor with high specific capacity and stability was prepared. This result was published online at Angew. Chem. Int. Ed. (DOI: 10.1002/anie.201603417). The first author of the dissertation was Li Wanwan, a doctoral student in the research group.

Electrochemically active hydrogels are expected to become flexible energy storage materials and have broad application prospects in the field of flexible electronic devices. However, the mechanical properties and stability of the existing electroactive hydrogels are poor, and it is difficult to meet the requirements for the electrode materials of the flexible supercapacitors. Therefore, designing and developing electroactive hydrogel materials with excellent mechanical properties and stability has important application value.

In response to this goal, Ma Mingming's research group used the principle of supramolecular structure design to use a boronate ester bond to self-assemble rigid polyaniline and flexible polyvinyl alcohol at the molecular level to form a three-dimensional dynamic network structure with high strength. Electroactive supramolecular hydrogels. The tensile strength of the hydrogel reached 5.3 MPa, and the elongation at break reached 250%. At a current density of 0.5 A/g, the specific capacitance value reached 928 F/g, and the specific capacitance retention rate after 1000 charge and discharge was reached. 90%. The hydrogel's mechanical properties, electrochemical activity and stability are significantly greater than the existing electroactive hydrogels. The hydrogel was assembled as an electrode material into a flexible all-solid supercapacitor, and a specific capacity of 153 F/g was achieved at a current density of 0.25 A/g, and the specific capacitance retention ratio after 100 times folding reached 100%. After 7 weeks, the specific capacitance retention rate reached 93%. This work provides new ideas for designing new types of flexible energy storage devices.

(Original title: China University of Science and Technology successfully prepared flexible supercapacitors based on high-strength polyaniline supermolecular hydrogels)