Combination of Alginate-Based Aerogels and Multifunctional Phase Change Microcapsules for Thermal Management of Supercapacitors

In order to improve the effect of temperature on the use of supercapacitors, this study first designed a double network structure of calcium alginate/polyaniline (CA/PANI) aerogel in which Ca2+ cross-linked CA is the first network and phytic acid cross-linked PANI is the second network. Due to the strong hydrogen bonding between PANI and CA and the ionic cross-linking between CA molecular chains, CA/PANI aerogels can form a stable porous network structure. Then, SiO2/poly(ethylene glycol) was obtained by emulsion polymerization. The p-phenylenediamine (PD)-graphene oxide (GO)@PANI composite structure was grafted on the surface of SiO2/PEG. The multifunctional microencapsulated phase change materials (MEPCM) can be used for both electrochemical and thermal energy storage. The MEPCM was dispersed in the CA/PANI double network to obtain a supercapacitor electrode with in situ temperature regulation. The CA/PANI/MEPCM electrode not only exhibits a significant phase change enthalpy of 149.4 J/g but also demonstrates impressive capacitance performance of 256 F/g at 55 °C under a current density of 0.5 A/g. After undergoing 10,000 charge–discharge cycles, the initial capacitance remains above 80%. This study lays the groundwork for innovative strategies in the development and application of phase change materials for thermal management in supercapacitors.