Study on fabrication of MnO 2 / CNTs composite by electrolysis in neutral solution and its applicability as cathode materials in Mg‐ion batteries

Effects of electrolysis conditions such as Mn 2+ ions, and CNTs concentration, temperature, and solution stirring on electrochemical precipitation of MnO 2 /CNTs composite on SS 304 stainless steel anode electrodes were studied by cyclic voltammetry (CV) method. Results show that the MnO 2 /CNTs was fabricated at the electrode potential was more positive than 0.8 V/SCE with a suitable solution composition of 0.5 M Na 2 SO 4 , 0.4 M MnSO 4 and CNTs 0.2 g/L, at 80 o C, and stirring speed ranging from 100 to 200 rpm. The obtained MnO 2 /CNTs composite materials contained a crystalline phase of MnO 2 akhtenskite. The presence of CNTs in the composite was observed by FESEM image. Electrochemical properties of the MnO 2 /CNTs composites were studied by CV method and galvanostatic charge‐discharge. The composite materials have good discharge capacity, its specific capacity was 92 mAh/g, after 35 charge‐discharge cycles the specific capacity of the material decreased to 69.2 mAh/g, equal to 75 % of the first cycle.