The effects of calcination on the electrochemical properties of manganese oxides

Abstract

Three different crystalline forms of Mn₃O₄ were successfully prepared by a liquid phase method with different additives. Using XRD, SEM, EDS, BET, compacted density and electrochemical analysis, the effects of different additives on the morphology, phase composition, surface characteristics, specific surface area, electrochemical and other physical and chemical properties of manganese oxides were investigated. The results showed that the rod type Mn₃O₄ was prepared by mixing ammonia water and anhydrous ethanol in a 1 : 1 ratio and an appropriate amount of cetylmethyl ammonium bromide as the additive. The rod-type Mn₃O₄ showed a maximum specific surface area of 63.87 m² g⁻¹ and has the advantages of low compaction density, no introduction of other impurities, and high adsorption potential. It also has excellent electrochemical performance and an impedance of 240 Ω. The specific capacity was as high as 666.5 mA h g⁻¹ at 1C current density and 382.2 mA h g⁻¹ after 200 cycles. The results also showed that the electrochemical performance of Mn₂O₃ prepared at 700 °C from the rod-type Mn₃O₄ was the best. When it was used as the anode material of a lithium-ion battery, it showed a high specific capacity of 712.1 mA h g⁻¹ after 200 cycles. Therefore, the rod-type Mn₂O₃ material has the characteristics of high capacity, low cost and environmental friendliness and is a promising candidate anode material for lithium-ion batteries.