Thermal batteries find use in applications such as emergency power systems and ejector seats in aircraft. As a result, systems need to be highly reliable. This requires a detailed knowledge of the structure and the stability of the individual components of the battery at operating temperatures (typically 400-500 °C). We are currently undertaking a project which involves the synthesis, properties and characterisation of materials which may be used as cathodes in thermal batteries. We have recently gained good electrochemical performances with materials which have not been characterised tested as cathodes. The aim of this experiment would be to gain accurate structural models for the cathode materials at elevated temperature and understand how the structure evolves with temperature.