A Tri-Mode Photothermal, Phase-Change, and Radiative-Cooling Film for All-Day Thermoelectric Generation

Area of Science:

• Materials Science
• Renewable Energy Engineering
• Nanotechnology

Background:

• Solar-thermal-electric conversion is promising for off-grid applications but limited by low output density and intermittency.
• Existing technologies struggle with consistent energy supply due to the fluctuating nature of solar radiation.

Purpose of the Study:

• To design and develop a multifunctional material for continuous solar-thermal-electric power generation.
• To overcome the limitations of intermittency and low output density in solar energy applications.

Main Methods:

• Development of microencapsulated phase change materials (MPCMs) with a n-Tetracosane core and TiO2/Ti2O3 composite shell.
• Fabrication of a thermoelectric system by coupling a polydimethylsiloxane and MPCMs film with a thermoelectric module.
• Characterization of MPCM properties including latent heat, photothermal conversion efficiency, and energy storage capacity.

Main Results:

• The developed MPCM demonstrated a high latent heat (144.5 J g⁻¹), excellent photothermal conversion efficiency (93.7%), and 100% energy storage capacity.
• The thermoelectric system achieved adaptive 24-hour uninterrupted power generation, with output power densities ranging from 6.1 to 21.1 W m⁻².
• The material successfully integrated photothermal conversion, phase change energy storage, and radiative cooling functionalities.

Conclusions:

• The innovative multifunctional material design enables adaptive energy harvesting from both solar radiation and cold space.
• This advancement offers new pathways for repeatable energy storage and high-quality utilization of solar energy.
• The developed technology holds significant potential for advancing all-day solar-thermal-electric power generation systems.