Materials Chemistry and Physics, Vol.196, 126-136, 2017
Effect of temperature on the electrochemical synthesis of MnO2 recycled from spent Zn-MnO2 alkaline batteries and application of recycled MnO2 as electrochemical pseudocapacitors
Manganese oxide was electrochemically synthesized from spent zincmanganese oxide alkaline batteries. The recycled MnO2 was then used as electrochemical pseudocapacitors. According to Raman spectroscopy, X-Ray Diffraction and XPS analysis primarily alpha-MnO2 films were grown at 25 C and 80 C, under galvanostatic conditions (i = 10 mAcm(-2)) and at a charge density of 1.0 Ccm(-2). A charge efficiency of 88.0% was obtained in the anodic electrodeposition of MnO2 at 25 C and 80 C. The effect of temperature on the anodic electrodeposition and the film capacitance was evaluated by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. The alpha-MnO2 film grown at 80 C exhibited a porous surface, and higher specific capacitance of 367.30 F g-1 at 1.0 mV(-1) and 386.30 F g(-1) at 1.25 A g(-1). The alpha-MnO2 film grown at 25 C showed a specific capacitance of 66.80 F g(-1) at 1.0 mV(-1) and 127.06 F g(-1) at 1.25 A g(-1). (C) 2017 Elsevier B.V. All rights reserved.