Investigating the potential of MnO₂ doped MoS₂ nanocomposite for enhanced energy storage supercapacitor applications: Energy density and stability

Supercapacitors are emerging as a feasible solution because of their quick charge-discharge and have remarkable potential in advanced electrochemical applications. However, they suffer from the limited energy density (E_D) and specific capacitance (C_sp). To address these challenges, MnO₂ is doped into MoS₂ at varying weight percentages (5, 10, 15, 20 and 25 wt%) designated as MM-5, MM-10, MM-15, MM-20, and MM-25 respectively. This approach aims to improve the electrochemical performance by tuning the charge storage behaviour through MnO₂ doping. The MM-10 nanocomposite achieves the value of discharge specific capacitance (C_dsp) of ∼ 515 F/g (at 1 A/g) from galvanostatic charge-discharge (GCD) tests. The E_D and power density (P_D) of the MM-10 nanocomposite electrode material are 15 Wh/kg at 0.4 A/g and 10,000 W/kg at 50 A/g, respectively, and retain 76 % of initial capacitance over 4000 cycles with coulombic efficiency of 98–101 %, demonstrating excellent cycling stability. The enhanced performance of MM-10 compared to other is attributed to the optimal MnO₂ doping and the formation of a porous structure. The better electrochemical performance of MM-10 nanocomposites holds a potential as supercapacitor electrode.