Lithium-ion batteries are widely adopted in the automotive field for their high energy density, long cycle life and efficiency, but they tend to generate heat during operations, which can degrade their performance and lifespan. High operating temperatures specifically impose the need for effective thermal management strategies. While the working principles behind batteries are straightforward, their internal processes are highly complex, with several factors contributing to potential overheating. Accordingly, designers are constantly invested in developing tools capable of understanding, predicting and mitigating thermal risks. This thesis addresses these challenges by developing thermal models to accurately predict the thermal and electrochemical behaviour of lithium-ion batteries.