3D printing flexible supercapacitors based on crosslinked poly (acrylic acid-co-vinylimidazole)

Supercapacitors are an attractive technology for energy storage applications as they allow for fast charging of devices. The fabrication of flexible supercapac-itors by additive manufacturing is a promising approach to produce energy storage components for applications where material flexibility and complex geometries are desirable. In this work, digital light projection (DLP) additive manufacturing is used to fabricate polymer electrolytes for flexible superca-pacitors based on crosslinked poly(acrylic acid-co-vinylimidazole) (PAAVim). Ion gels are prepared through equilibration with 4M lithium chloride (LiCl) in ethylene glycol, deionized (DI) water and ethylene glycol/DI water mixtures. Flexibility and stretchability varied depending on the equilibration solvent with prepared PAAVim/LiCl polymer electrolytes exhibiting up to similar to 700% elongation at break. Subsequent flexible supercapacitors fabricated by sandwiching the ion gel between carbon cloth electrodes delivered 60 F/g specific capacitance at the scan rate of 0.2 A/g with an energy density of 8.3 Wh/kg and a power density of 99.8 W/kg. Overall, this work demonstrates the fabrication of flexible capaci-tors through DLP additive manufacturing, where the resulting material physical and electrochemical properties can be varied through control over the resin chemistry.