Pulsed electro-synthesized tunable crystallite sizes ZnMn2O4/Mn2O3 nanocomposite as high-performance cathode material for aqueous zinc-ion batteries

Abstract

Rechargeable aqueous zinc ion batteries (ZIBs) are one of the most promising candidates for large-scale energy storage, due to their high capacity, high hydrogen evolution potential, safe and cost-effective components while benefiting from the abundance of active materials. However, ZIBs still suffer from suitable cathode materials with high capacity and superior cycling stability. Herein, we study a new strategy for the synthesis of tunable crystallite sizes ZnMn2O4/Mn2O3 nanocomposite using the pulsed potential method. The effect of synthesis potential on structural, morphological, and electrochemical properties of nanocomposite was investigated via different characterization techniques. According to our results, the functional and electrochemical properties of ZnMn2O4/Mn2O3 nanocomposite are profoundly affected by the synthesis potential. The crystallite sizes of synthesized nanocomposites can be tuned from 20.2 nm to 29.3 nm, depending on the applied potential. However, the exposed surface area of nanomaterials is ranged between 50.3 m2 g−1 and 132.0 m2 g−1. The developed nanocomposite was investigated as the cathode material for aqueous zinc ion batteries. The ZnMn2O4/Mn2O3 nanocomposite exhibited an excellent discharge capacity of 216.8 mAh g−1 at 0.2 A g−1 after 200 cycles. In addition, the developed cathode showed to preserve 97.8% of its initial capacity for 2000 cycles at 2 A g−1. Apart from the high specific capacity and long cycle stability, the facile synthesis method can offer the ZnMn2O4/Mn2O3 nanocomposite as a high-performance cathode material for durable zinc ion batteries.