Electrochemical Properties of Electrodes Based on Мn3O4, Mn2O3 in Non-Aqueous Electrolytes with Magnesium or Lithium Perchlorate

Abstract

Magnesium battery is considered as an alternative to more expensive and environmentally unsafe lithium battery. New strategy proposes for practical magnesium system according to which the high energy and current density are achieved due to surface redox reactions and capacitive non-Faraday processes. This strategy was successful in nanometer anode material Mn3O4. In the paper, the electrode material (Mn3O4, Mn2O3) with the particles above submicron level in a composition with a carbon filler Norit was synthesized and investigated as less harmful to human health. A comparison of (Mn3O4, Mn2O3, Norit) characteristics is performed in cell with magnesium- and lithium perchlorate electrolytes based on glymes. The possibility was shown and the electrochemical reformation conditions of (Mn3O4, Mn2O3, Norit) are determinate in magnesium electrolytes to obtain a capacity of the order of 200 mAh·g-1. The start lithiation capacity of (Mn3O4, Mn2O3, Norit) reaches to 980 mAh·g-1 in lithium perchlorate electrolyte, whereas delithiation capacity is reduced to 250-300 mAh·g-1. The Norit carbon material is an electrically conductive additive, but it is also electrochemically active in magnesium electrolyte. However, the rate and capacitive characteristics of (Mn3O4, Mn2O3, Norit) limited by the size of the particles of the thermal synthesized low-conducting Mn3O4, Mn2O3 oxides. The problem of using Mn3O4 in high energy magnesium battery capable of replacing lithium battery is discussed. For the replacing, magnesium non-aqueous electrolyte is needed with wide window of electrochemical stability for Mn3O4–anode compatible also with high voltage cathode materials.