Defect-engineered Mn3O4/CNTs composites enhancing reaction kinetics for zinc-ions storage performance

The designing of reasonable nanocomposite materials and proper introduction of defect engineering are of great significance for the improvement of the poor electronic conductivity and slow reaction kinetics of manganese-based compounds. Herein, we report manganese-deficient Mn3O4 nanoparticles which grow in-situ on highly conductive carbon nanotubes (CNTs) (denoted as DMOC) as an advanced cathode material for aqueous rechargeable zinc-ion batteries (RAZIBs). According to experimental and calculation results, the DMOC cathode integrates the advantages of enriched Mn defects and small particle size. These features not only enhance electronic conductivity but also create more active site and contribute to fast reaction kinetics. Moreover, the structure of DMOC is maintained during the charging and discharging process, thus benefiting for excellent cycle stability. As a result, the DMOC electrode delivers a high specific capacity of 420.6 mA h g−1 at 0.1 A g−1 and an excellent cycle life of 2800 cycles at 2.0 A g−1 with a high-capacity retention of 84.1%. In addition, the soft-packaged battery assembled with DMOC cathode exhibits long cycle life and high energy density of 146.3 Wh kg−1 at 1.0 A g−1. The results are beneficial for the development of Zn/Mn3O4 battery for practical energy storage.