Ni₂Mn-layered double oxide electrodes in organic electrolyte based supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitors are essential for future mobility (e.g., electric vehicles), demanding higher voltage and energy density.
• Conventional active carbon supercapacitors have performance limitations, necessitating advanced electrode materials.
• Metal hydroxides/oxides offer promise, but aqueous electrolytes limit their working voltage and cycle stability.

Purpose of the Study:

• To develop novel mixed metal oxide electrodes for enhanced supercapacitor performance.
• To investigate Ni2Mn-layered double oxides (Ni2Mn-LDOs) as potential supercapacitor electrodes in organic electrolytes.
• To explore the synergistic effects of mixed metal oxides for improved energy density and voltage.

Main Methods:

• Synthesis of Ni2Mn-LDOs via calcination of a layered hydroxide precursor at 400 °C.
• Electrochemical evaluation of Ni2Mn-LDOs as supercapacitor electrodes in organic electrolyte.
• Comparison of Ni2Mn-LDO performance against single metal oxides (NiO, MnO2) and physical mixtures.

Main Results:

• The optimized Ni2Mn-LDO electrode achieved a high working voltage of 2.5 V and a specific capacitance of 44 F g-1 (at 1 A g-1).
• Ni2Mn-LDO demonstrated superior performance compared to individual NiO, MnO2, and their physical mixture.
• The enhanced performance is attributed to the unique porous structure, high surface area, and homogeneous mixed metal oxide network.

Conclusions:

• Layered double oxides (LDOs) offer significant advantages over single-component metal oxides and physical mixtures for supercapacitor applications.
• Ni2Mn-LDOs are promising electrode materials for high-performance supercapacitors in organic electrolytes.
• This study highlights the potential of LDH precursors for developing advanced mixed metal oxide-based supercapacitors.