The widespread use of lithium-ion batteries and the demand for high-performance battery packs have made battery thermal modelling a crucial research area. This field helps to understand and manage the heat generated and the temperature distribution during battery operation. Effective thermal management is essential to ensure safety, extend battery lifespan and optimise efficiency. In this work, heat generation is identified as the primary driver of temperature change and distribution within the cell. Various battery models are reviewed and classified, driving the selection of the right model according to the application. Several thermal characterisation methods are described in detail, with a focus on experimental techniques that can be applied in-situ. Finally, the challenges posed by temperature distribution are discussed extensively, with a focus on how these challenges could shape the future research and design of the next generation of lithium-ion cells and battery packs.