Project aims to explore novel tungsten bronze structured ferroelectric ceramics for potential applications as power capacitors. New wide-bandgap semiconductor technologies have the potential to provide active components that can operate at 250-300C allowing reductions in heatsink size and equipment weight. However, due to the much higher switching speeds of wide-bandgap devices in power electronic equipment, passive and active components must be in close proximity (e.g. co-packaged), demanding high temperature operation of passive components. Existing Class II capacitors are specified to an upper working temperature of less than or equal to approximately 200C. The availability of a new generation of dielectric charge storage components will play a key role in the energy transition from fossil fuels to electrification. The project will focus on crystal and microstructural engineering of chemically modified tungsten bronze ceramics, with a focus on relating structure to charge storage characteristics, targeting R-type stability in capacitance over a wide temperature range, from -55 to 300C.