Phase change materials for automotive applications

Abstract

This industrial PhD project aims to develop cost-efficient battery thermal management systems (BTMS) using phase change materials (PCMs) for passive temperature control in electric vehicles (EVs). The research includes a literature review, sourcing and quantifying phase change properties of commercial PCM products, and using differential scanning calorimetry to determine critical parameters like melting temperature and fusion enthalpy. Novel diester PCM candidates are synthesised using green chemistry principles, optimised through Design of Experiment (DOE), and experimentally validated. COSMOtherm is employed to screen potential PCM binary mixtures via eutectic composition, with promising compositions experimentally validated. Compatibility studies assess the thermophysical properties, safety, and durability of the novel PCMs compared to industrial prototypes. The study also addresses the challenge of solidifying supercooled sugar alcohols by enhancing their crystallisation using acetamide eutectic mixtures. COSMOtherm is used to model eutectic points using cyclohexyl diesters and terephthalate diesters, demonstrating highly accurate predictions with deviations of less than 3.2 K for eutectic temperatures. The in-house synthesised novel saturated cyclic diester, didodecyl cyclohexane dicarboxylate (CH12), emerged as the best candidate, showing superior performance in specific heat capacity, electrical resistivity, thermal stability, and durability compared to commercial PCM products, demonstrating its potential for BTMS applications in EVs.

Thesis is embargoed until 31 July 2035.

Date of Award	Jul 2025
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Petronas Research
Supervisor	John Holbrey (Supervisor), Marijana Blesic (Supervisor) & Gosia Swadzba-Kwasny (Supervisor)