Performance Characterization of Form-Stable Carbon-based Network Microcapsules for Thermal Energy Storage

In order to solve the problems of easy leakage and low thermal conductivity of paraffin in molten state. In this study, modified phase-change microcapsules with paraffin as the core material, melamine-formaldehyde resin as the wall material, flake graphite (FG), multilayer graphene (GNP) and expanded graphite (EG) as heat conduction additives were prepared by in-situ polymerization. The results show that the thermal conductivity of the composite phase change material gradually increases with the increase of the mass fraction of carbon additives, and the heat transfer enhancement effect of EG/MPCMs composite phase change material is the most obvious, with a thermal conductivity of 1.9 W/(m.K), which is 9.5 times that of pure paraffin. The addition of FG/MPCMs, GNP/MPCMs and EG/MPCMs carbon-based materials have little effect on the latent heat of phase change microcapsules, and the latent heat retention rates are 83.8%, 78.8% and 86.4% respectively. Microcapsules with phase change have good leakage prevention performance, and there are two obvious temperature buffering stages in the process of melting and condensation, so which have good thermal regulation ability. Compared with the previous studies, the prepared composite phase change microcapsules have high thermal storage capacity while ensuring high thermal conductivity, and have potential applications in industry.