Representational image.iStock Photos
A team of materials scientists has developed a bio-based carbon material that could solve one of the most stubborn problems in thermal energy storage: leakage during melting.
The new material stores heat efficiently while keeping its shape intact, even as the heat-storing compound transitions from solid to liquid.
The research focuses on phase change materials, which absorb and release heat as they melt and solidify.
These materials are widely studied for applications ranging from building temperature control to solar energy storage and electronic thermal management.
However, many organic phase change materials leak when they melt, limiting their durability and real-world use.
To address this issue, researchers turned to chitin, a natural polymer found in crustacean shells and fungi. Chitin is abundant, renewable, and often discarded as waste, making it an attractive candidate for sustainable materials engineering.
In the new study, scientists converted chitin into an ultralight aerogel and then carbonized it to form a porous carbon framework.
This structure was designed to act as a host for stearic acid, a common organic phase change material known for its high heat storage capacity but persistent leakage issues.
Turning waste into carbon
The chitin-derived carbon aerogel features a highly interconnected pore network with a large pore volume.
These pores physically trap molten stearic acid, while capillary forces and hydrogen bonding prevent it from flowing out during melting.
“Our goal was to design a low cost and environmentally friendly support that can hold large amounts of phase change material without leakage,” said corresponding author Hui Li.
“Chitin is abundant, renewable, and naturally rich in nitrogen.”
The resulting composite material can contain up to 60 percent stearic acid by weight without showing visible leakage.
Even when the stearic acid melts, the overall structure remains solid, solving a major challenge faced by many organic phase change systems.
Thermal testing showed that the composite achieved a melting enthalpy of about 118 joules per gram, a value higher than many previously reported biomass-derived phase change materials.
The carbon framework also improved thermal conductivity, allowing heat to move in and out of the material more efficiently.
Built for repeated cycling
Durability was another key focus of the study. After 100 heating and cooling cycles, the composite retained more than 97% of its original heat storage capacity, with little change in the phase change temperature.
“Long term reliability is essential for real world energy storage systems,” Li said. “Our results show that this chitin based carbon aerogel can repeatedly store and release heat.”
The researchers also found that nanoscale confinement within the carbon pores increased the activation energy required for stearic acid to undergo phase change.
This suggests improved thermal stability, driven by interactions between the nitrogen-doped carbon surface and the organic molecules.
Because chitin can be sourced from seafood waste and fungal biomass, the approach offers a pathway to turn biological byproducts into high-value energy materials.
The team believes the strategy could be adapted for other phase change materials and temperature ranges, opening doors for greener thermal energy storage systems, as reported in Sustainable Carbon Materials.
