Nanoflake driven Mn2O3 microcubes modified with cooked rice derived carbon for improved electrochemical behavior

Abstract

Mn₂O₃ microcubes, symmetrically formed out of the systematic stacking of nanoflakes, built with nanoparticles in the 30–50 nm range have been obtained from a simple co-precipitation method. Excluding the requirement of a structure directing additive, the currently adopted synthesis protocol signifies the vital role of the rate of (NH₄)HCO₃ precursor addition, which has been optimized as 2 h for 300 mL to obtain uniformly stacked nanoflakes of Mn₂O₃ to form microcubes with desired morphological features. Cooked rice carbon (CRC), obtained from a filth-to-wealth conversion, has been used as conducting additive and an optimum concentration of 20 wt% CRC was found to be sufficient to form Mn₂O₃/CRC with improved lithium intercalation/de-intercalation behavior. The twin advantages, namely exploitation of a cheap and eco-benign composite additive obtained from a common domestic waste in the form of CRC and the optimized speed of addition of (NH₄)HCO₃ to form Mn₂O₃ microcubes obtained from nanoflakes offer advantages in terms of enhanced electronic conductivity and provision to buffer the volume changes of Mn₂O₃ anode, respectively. The optimized Mn₂O₃/CRC-20 composite anode exhibits an appreciable capacity of 830 mA h g⁻¹ after formation cycle and an acceptable capacity of 490 mA h g⁻¹ after completing 100 cycles, under the influence of 50 mA g⁻¹ current density. Further, Mn₂O₃/CRC-20 anode exhibits a reasonable capacity of 450 mA h g⁻¹ at 100 mA g⁻¹ up to 50 cycles and qualifies itself as a potential anode material.