The Effect of Voltage and Time In Synthesis Manganese Dioxide from Manganese Sulfate Precursor

Abstract

The utilization of manganese dioxide (MnO₂) as a cathode material for lithium-ion battery has attract many attentions because of their excellent electrochemical properties which have high theoretical storage capacity of 615 mAh/g. In this study, synthesis of MnO₂ was carried out from manganese sulfate (MnSO₄) precursor which is a pregnant leach solution from the leaching process of manganese ore from Trenggalek Regency. The electrolysis method has been used in this synthesis of MnO₂ in an electrochemical cell consisting of two graphite electrodes with dimensions (16 x 5 x 0,3) cm. The purpose of this study is to determine the effect of voltage and time to particles amount of MnO_2, to determine the phase and crystal structure of MnO₂ and its morphological microstructure. The electrolysis process was carried out in 2000 ml of MnSO₄ solution under constant stirring at 60^oC with DC voltage varied by 2, 4, 6 and 8 volt and time varied by 4, 8, 12 and 16 hours. The precipitates formed at anode were separated, then the particles were dried at 110^oC for 2 hours. The main contain of MnO₂ were analyzed by X-Ray Fluorescence (XRF), the phase and crystal structure were evaluated by X-Ray Diffraction (XRD) and the morphological microstructure were captured by Scanning Electron Microscope (SEM). The results revealed that the highest particles amount of MnO₂ is 31,63 grams which is electrolyzed at 8 volts for 16 hours. The highest purity of MnO₂ is 89,23% which is electrolyzed at 2 volts for 16 hours. The particles produced were α-MnO₂ with a tetragonal crystal system and nearly spherical in shape with size particles ranged from 136,01-202,48 and 144-352 nm.