A high-performance carbon-carbon(C/C) Quasi-Solid-State Supercapacitor with Conducting Gel Electrolyte

摘要

The development of the electric double-layer capacitors (EDLCs) that pursue for the advantages of easily carrying, no leaking and high capacitance has been a strong objective at the moment. Here a new type gel electrolyte with a high special conductivity of 15.06 mS.cm(-2) was fabricate by immersing polyacrylamide gel (PAM-G) matrix in 6 M KOH aqueous solution for 60 hours. As expected, the assembled quasi-solid-state supercapacitor based PAM-G electrolyte exhibits a specific capacitance (of 196 F.g(-1) and 156 F.g(-1) at the charge-discharge current density of 1 A.g(-1) and 10 A.g(-1), respectively), maximum power of 10 kW.kg(-1) along with energy density of 28.6 Wh.kg(-1) (under the current density of 10 A.g(-1)), and the capacitance retention rate keeps 98% after 5000 cycles at 1 A.g(-1), demonstrating a high cycling stability, an excellent rate capability as well as a high specific capacitance of the device. The promising electrochemical performance could be attributed to the unique homogeneous and microporous three-dimensional structure of the PAM-G which can greatly enhance the permeability and transportation of different ions.