Development of non-deform micro-encapsulated phase change energy storage tablets

This study evaluates the concept of developing a non-deform phase change energy storage material possessing higher thermal conductivity and energy storage density through pressure compaction process. The theoretical and experimental investigations have shown that the technique is able to reduce porosity and increase conductivity and energy storage density of a composite material. Even though there was some measure of plastoelasticity due to decompression, the average porosity was reduced from 62% to 23.8% at a relatively low compaction pressure of 2.8 MPa without any structural damage to the tested sample. The mean energy storage density increased by 97% and the effective thermal conductivity also increased by twenty five times despite 10% reduction in its latent heat capacity. There is however the need for further development towards minimising the effect of decompression and achieving stronger energy storage tablets at relatively low compaction force.

► Sample achieved an average porosity of 23.8% as against the pre-compaction level of 62%.
► The mean energy storage density increased by about 97% i.e. from 46.6 MJ/m3 to 91.76 MJ/m3.
► Thermal conductivity increased to 2.3 W/m K which is about 25 times higher than the raw MEPCM.