A Novel Supercapacitor with Integrated Photosensitive Electrode to Enhance Its Capacitance Under Solar Light

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Supercapacitors (SC) are crucial energy storage devices.
• Developing advanced electrode materials is key to improving SC performance.
• Integrating solar energy harvesting with energy storage offers synergistic benefits.

Purpose of the Study:

• To engineer a novel photosensitive supercapacitor (SC) with enhanced energy storage capabilities.
• To investigate the synergistic effects of solar energy photogeneration and electrochemical charge storage.
• To explore the charge storage mechanisms in a graphene/V-LFO composite electrode under illumination.

Main Methods:

• Fabrication of a supercapacitor (SC) using graphene (Gr) electrodes coated with LaFe0.94V0.01Mn0.05O3 (V-LFO) perovskite.
• Characterization of the electrochemical performance (capacitance, energy density) under dark and illuminated conditions.
• Analysis of charge storage mechanisms involving photogenerated charge carriers and photocatalytic radical generation.

Main Results:

• The Gr/V-LFO-SC exhibited a capacitance of 581.8 F g⁻¹ and energy density of 80.8 Wh kg⁻¹.
• Under natural sunlight illumination, capacitance increased to 876.9 F g⁻¹ and energy density to 121.8 Wh kg⁻¹, a ~50% enhancement.
• Photogenerated electrons/holes and photocatalytically generated O₂²⁻ and ∙OH radicals contributed to enhanced charge storage via redox reactions and EDL mechanisms.

Conclusions:

• The developed photosensitive supercapacitor demonstrates a significant enhancement in energy storage performance when exposed to sunlight.
• The synergistic effect of solar energy conversion and electrochemical storage in the V-LFO perovskite composite electrode is confirmed.
• This research presents a promising pathway for developing advanced solar-enhanced energy storage devices.