Co(OH)2/Ag based interdigital micro-supercapacitor fabricated via laser welding and electrodeposition with excellent bendability

Ag/Co(OH)(2) interdigital electrode with unique micro-flower structure was fabricated by welding Ag nanoparticles to polyproplene (PP) substrate via laser irradiation, followed by electrodeposition of Co(OH)(2). The Ag/Co(OH)(2) composite exhibited specific capacitance of 729 F.g(-1) at current density of 0.5 A.g(-1). Micro-supercapacitor was fabricated through coating KOH/polyvinyl alcohol hydrogel as electrolyte onto the interdigital electrode. Maximum energy density of 9.47 Wh.kg(-1) at power density of 300 W.kg(-1) had been obtained for the micro-supercapacitor with excellent bendability, demonstrating capacitance retention of approximately 97.67% after 1000 bending cycles. The enhanced bendability compared with the supercapacitors reported previously may be attributed to that the surface of thermoplastic PP melted under laser irradiation to form a melt, which soaked Ag nanoparticles and then solidified, thus realizing the good adhesion between PP and Ag. This technology opens up opportunities for facile and universal fabrication of high performance micro-supercapacitors.