Molybdate incorporated poly(acrylic acid) electrolytes for use in quasi-solid state carbon based supercapacitors: Redox-active polychelates

The use of poly (acrylic acid) (PAA) as a host matrix with a guest electroactive additive, ammonium molybdate, (Mo) is an interesting approach representing a novel redox active polymer-metal chelate electrolytes (polychelates). The quasi-solid state supercapacitors were made up of carbon composite electrodes (CC) and polychelates, PAA-MoX (X: 1, 3, 5, and 10) where X represents the doping fraction (w/w) of Mo in PAA. The excellent thermal stable structure of the polychelates was supported by high ionic conductivity and ideal bending-stretching properties, giving it a high compatibility for the supercapacitors. The supercapacitor device produced with PAA-Mo5 electrolyte showed a remarkable specific capacitance of 327.50 F g(-1), almost 15 times better in performance compared to pure PAA device. The same device with a combination of CC/PAA-Mo5/CC provided an energy density of 45.49 Wh kg(-1) at a power density of 251.92 W kg(-1). A remarkable loop stability of the PAA-Mo5 device was maintained after 94 charge-discharge cycles, with 94% of the initial performance. In addition, an LED light was successfully operated by a 1.5 x 3 cm size supercapacitor containing the PAA-Mo5 electrolyte. (C) 2020 Elsevier Ltd. All rights reserved.