Water/Oxygen Circulation-Based Biophotoelectrochemical System for Solar Energy Storage and Release

Area of Science:

• Renewable Energy Systems
• Electrochemical Engineering
• Materials Science

Background:

• Artificial photoelectrochemical devices face challenges in providing consistent power due to sunlight intermittency.
• Existing photoelectrochemical cells (PECs) often lack integration with energy storage solutions.
• Developing robust systems for solar energy capture and storage is crucial for grid-scale applications.

Purpose of the Study:

• To design and demonstrate a water/oxygen circulation-based biophotoelectrochemical system (BPECS) for on-demand electric power generation.
• To address the intermittent nature of solar energy by integrating a capacitor electrode into a photobiofuel cell (PBFC).
• To enhance compatibility and feasibility for tackling solar intermittency in artificial PEC devices.

Main Methods:

• Integration of a polypyrrole (PPy) capacitor electrode into a photobiofuel cell (PBFC) to create a BPECS.
• Implementation of a self-circulating water/oxygen system for intrinsic safety and cost-effectiveness.
• Utilizing an alternate two-step energy conversion process: solar-to-chemical/electric and chemical-to-electric.

Main Results:

• The BPECS achieved maximum power output densities of 0.34 ± 0.01 mW cm⁻² (light) and 0.19 ± 0.02 mW cm⁻² (dark).
• Demonstrated stable long-term cycling performance for efficient solar energy storage and release.
• The system exhibited high-effective solar energy utilization through its integrated design.

Conclusions:

• The developed BPECS offers a feasible and intrinsically safe approach to overcome solar intermittency for power generation.
• This modular and integrated system design improves compatibility among PEC, BFC, and capacitor devices.
• The BPECS presents significant potential for grid-scale photovoltaic energy storage and future artificial biophotoelectrochemical systems.