Investigation on the electrochemical performance of hausmannite Mn₃O₄ nanoparticles by ultrasonic irradiation assisted co-precipitation method for supercapacitor electrodes

Figures & data

Figure 1. Schematic diagram of synthesized Mn₃O₄ nanoparticles.

Figure 2. Powder X-ray diffraction (XRD) pattern of the synthesized Mn₃O₄ nanoparticles.

Table 1. XRD parameters of synthesized Mn₃O₄ nanomaterials.

Parameters	Mn3O4 nanoparticles
d, nm (Scherrer formula)	39.9
d, nm (W–H relation)	36.5
ε (× 10^−3)	13.75
δ × 10^−3 (Lin-nm^−2)	0.75

Figure 3. XPS (a) Survey spectrum, (b) deconvolution spectra of Mn 2p, (c) deconvolution spectra of Mn 3s and (d) deconvolution spectra of O 1s for Mn₃O₄ nanoparticles.

Figure 4. FE-SEM morphology and EDX spectra of Mn₃O₄ nanoparticles.

Figure 5. Cyclic voltammetry curves of prepared Mn₃O₄ electrode material recorded at scan rate of 5–100 mV s⁻¹.

Figure 6. Charge-discharge curves of the prepared electrode materials at different current densities of 1–10 A g⁻².

Figure 7. Specific capacitance vs. scan rate for prepared Mn₃O₄ electrode materials at different scan rate. Insert figure showing the decrease in specific capacitance with increase in applied current.

Figure 8. (a) Cycle stability for the electrode Mn₃O₄ material recorded at the current density of 3 A g⁻¹ up to 1000 cycles and (b) Continuous charge-discharge cycles.

Figure 9. Nyquist plot for prepared Mn₃O₄ electrode materials. Insert figure shows the impedance at higher frequency region.