New CPCM method reduced expansion and raised conductivity rates

Researchers from the University of Birmingham, along with collaborators from Silesia and Southeast University, studied the enhancement of composite phase change materials (CPCMs) for thermal energy storage. Latent heat TES systems use phase change materials (PCMs) but face issues like low thermal conductivity and volume changes. CPCMs, made by embedding PCMs in porous matrices, help mitigate these but often involve complex or costly processes and limited PCM content. The study used SiO₂ nanoparticles to improve CPCM fabrication via a simple mix-sintering method. CPCMs with over 72 % NaNO₃ content were produced, exceeding the usual 60 % limit. The modified CPCM showed a 14 % drop in energy storage density, a 28 % rise in thermal conductivity, and reduced thermal expansion compared to pure NaNO₃. The findings supported CPCMs as a viable approach to address material challenges in latent heat TES systems.