The low thermal conductivity of PCMs ( for example paraffin wax has a thermal conductivity and issues surrounding leaking have so far prevented widespread uptake of organic PCMs into BTMS. To mitigate low thermal conductivity challenges, the introduction of thermally conductive additives including nanoparticles and graphene, has been explored. Additionally, to limit leakage and material loss composite PCM structures have been designed to hold the PCM in place during operation and impart properties on to the PCM. While composite-PCMs have been shown to be effective, issues remain over the surface area to volume ratio required to effect effective and efficient BTMS. Furthermore, ensuring good contact with the cells for effective heat transfer and the mass added to the battery pack are critical considerations. Mico-encapsulation, the formation of a core-shell, has previously been used to provide protection to PCMs. The encapsulation also has the added benefit that the shell material can be modified to alter the properties of the core within. For example, graphene oxide-carbon nanotube composite shells have been used to greatly increase the thermal conductivity of capsules containing docosane. The micro-capsules also have an increased surface area compared to bulk PCM increasing the efficiency and efficacy of the PCM core being used. Furthermore, a slurry of nano capsules containing PCM has been demonstrated to be an effective BTMS simulating a cell using a joule heated block. The results of computational studies have also indicated the good potential for encapsulated PCMs to be used as part of an effective BTMS. However, the use of encapsulated PCMs in practical studies on actual Liion cells have so far been limited. In this work, coatings containing carbon microencapsulated octadecane (C18H38, melting point 27 °C) are applied to cylindrical Li-ion cells for evaluation as a passive BTMS. The performance of the micro-encapsulated PCM coating and the heat storage capabilities versus uncoated cells was investigated using thermal imaging and image processing during electrochemical cycling of cells.