Phase change materials (PCMs) are believed to have great potential as thermal energy storage (TES) due to their high energy storage density and less moving parts or less maintenance. However, the use of PCM is limited due to poor thermal properties, high degree of supercooling and insufficient optical absorbance of the materials. To overcome these issues, in this work a inorganic PCM PlusIce S70 salt hydrate was developed by synergistically incorporating hybrid graphene nanoplatelets (GNP) and coconut shell biochar (CSB) at different concentrations (0.2–1.0 wt%) to enhance the thermal conductivity and other properties. A comprehensive characterization was conducted to evaluate the thermal conductivity, supercooling behavior, latent heat, thermal/chemical stability, optical behavior and reliability after 500 cycles. The optimized composite PCM was integrated with a heat sink used in electronic cooling systems, and its thermal management performance was compared with conventional PCM. The modified PCM composite exhibited a substantial reduction in supercooling by 11.92%, whereas the thermal conductivity and optical absorbance was improved by 96.42% and 300%, respectively. In addition, the melting enthalpy of the nanocomposite was slightly increased from 107.3 J/g to 113 J/g due to the larger surface area and porous nanoparticle. Most importantly, the developed PCM composite is chemically and thermally stable even after 500 consecutive thermal cycles. When integrated with a heat sink, the S70-0.8GNP:CSB significantly reduced the temperature rise compared to pure PCM, thereby enhancing the reliability and cooling efficiency of electronic components. Thus, adding S70-0.8GNP: CSB to heat sinks can significantly improve the effectiveness of passive cooling for electronic device thermal control.
Rajamony et al. (Mon,) studied this question.