Mass fraction

Phase (matter)

Engineering

Ecology

Biology

Phase change

Materials science

Thermal conductivity

Power (physics)

Chemical engineering

Solar energy

Waste management

Latent heat

Phase-change material

Thermodynamics

Physics

Nanotechnology

Organic chemistry

Thermal

Energy storage

Process engineering

Composite material

Chemistry

Meteorology

Thermal energy storage

Thermal energy

Engineering physics

Nano Energy

A sort of novel microencapsulated phase change materials (PCMs) has attracted much attention for energy storage. However, the solar energy utilization efficiency of traditional microcapsulated PCMs is still not very high up to date. In this work, new [email protected] structured [email protected]2/Ti4O7 composite microcapsules were developed to harvest environmental full-spectrum sunlight by smart and rational design using a sol-gel method. The SiO2 shell not only prevented the leakage of paraffine, but also improves its thermal conductivity. The black 300 nm Ti4O7 particles, which were successfully embedded into the SiO2 shell, can achieve the efficient absorption of sunlight and simultaneously high conversion from light to thermal. The resultant [email protected]2/Ti4O7 microcapsules retained most enthalpy of paraffin, increased its stability, and exhibited an excellent thermal energy storage performance. The thermal conductivity of [email protected]2/Ti4O7 microcapsules was significantly enhanced by 334.87% (1.322 W m−1 K−1) compared with 0.304 W m−1 K−1 of one for paraffin. When the mass fraction of Ti4O7 nanoparticles is 3 wt% of paraffin, these [email protected]2/Ti4O7 microcapsules exhibited remarkable 85.36% of photo-thermal storage efficiency compared with 24.14% of one for paraffin. Due to their huge superiority of high efficient use of abundant solar energy in natural resources, these new photo-driven PCMs are very promising materials for solar-to-thermal conversion and energy storage.

Solar-driven phase change microencapsulation with efficient Ti4O7 nanoconverter for latent heat storage