Bloom gelatin template based Mn₃O₄ nanoparticles synthesis for electrochemical application in aqueous rechargeable zinc ion battery

In this study, Mn₃O₄ nanoparticle was synthesized using Mn(CH₃COO)₂ and bloom gelatin as template of weight ratio 1:1 for the application in aqueous rechargeable zinc ion battery (ARZIB). The preparation of Mn₃O₄ was confirmed by FTIR, Raman spectra, FESEM, EDX, and XRD. Solid-state UV-Vis spectroscopic technique was used to identify its low optical band gap (2.75 eV) which indicated its semiconductor property. With additives, prepared Mn₃O₄ was used as cathode material, thereby CR-2032 coin cell of ARZIB was fabricated. The coin cell delivered a high specific discharge capacity of 219.33 mAh/g at 100 mA/g current density with columbic efficiency of 98.09%. It also showed excellent capacity retention, 92.69% and 64.84% after 200 and 1000 charge-discharge cycles, respectively. To check the effect of gelatin, Mn₃O₄ nanoparticles were further synthesized keeping the raw material constant and changing the amount of gelatin from zero to three fold. XRD was used to characterize the further prepared Mn₃O₄ and similar CR-2032 coin cells were fabricated and tested by cyclic voltammetry and battery charging-discharging profile. Results showed gelatin plays significant role in the surface morphology of Mn₃O₄ nanoparticle as well as the zinc ion storage capacity. The work offers a facile and cost-effective approach for preparing cathode material of ARZIBs.