# A 1-Tetradecanol-1, 10-Decanediol Binary Eutectic Mixture/Expanded Graphite Composite Phase Change Materials for Thermal Energy Storage

## TL;DR

A new composite material for thermal energy storage combines a eutectic mixture with expanded graphite to improve thermal conductivity and reduce leakage.

## Contribution

A binary eutectic system with expanded graphite is developed, offering enhanced thermal conductivity and stability for thermal energy storage.

## Key findings

- The composite material has a thermal conductivity of 4.642 W/(m·K), 12 times higher than the pure eutectic.
- The material retains over 87% of its latent heat after 2000 thermal cycles.
- The composite exhibits melting and solidification temperatures of 37.77 °C and 29.38 °C with latent heats of 218.80 J/g and 216.66 J/g.

## Abstract

Organic phase change materials show potential for thermal energy storage, but their scalable implementation is limited by fixed phase change temperatures, molten leakage, and low thermal conductivity. To address the temperature constraint, a binary eutectic system of 1-tetradecanol and 1,10-decanediol is prepared, expanding the operational temperature range for building thermal management. Compositing the eutectic with expanded graphite yields a composite material that exhibits a low leakage and a markedly improved thermal conductivity of 4.642 W/(m·K), which is approximately 12 times that of the pure eutectic. The composite maintains distinct phase transition properties, with melting and solidification temperatures of 37.77 °C and 29.38 °C and corresponding latent heats of 218.80 J/g and 216.66 J/g. It also demonstrates a good cycling stability, retaining over 87% of the original latent heat after 2000 thermal cycles. While these findings remain valid under controlled conditions, further studies are required to evaluate their practical feasibility and long-term durability in real-world scenarios. This work establishes a systematic approach for fabricating composite phase change materials and provides a promising candidate for building thermal management applications.