Plasma-Processed 3D Electrodes for Micro-Supercapacitors – PERFORM

Current research on micro-supercapacitors aims at increasing the energy density while maintaining high power density and lifetime. As the energy density is thickness-limited, the progress continues mostly towards the development of 3D architectures in order to increase the specific surface. A key issue remains the conformal deposition of the thin film electrode on 3D templates. It is essential to develop a thin film deposition technique which allows conformal deposition onto high aspect ratio microstructures, while providing enough freedom to tune materials microstructural and electrochemical properties. e-HIPIMS technology has the potential to achieve these objectives by benefiting from a high degree of ionisation of the vapour from the target material. PERFORM project has the objective to investigate the conformal deposition of thin film electrodes for micro-supercapacitors by e-HiPIMS. The project will rely on the novel power supply developed in IMN, allowing to generate up to six synchronized pulses controlled with microsecond resolution, in a same discharge. At first, the project will aim at characterizing Ar-Ti-N2 e-HiPIMS plasmas by time-resolved techniques such as mass spectrometry and optical emission spectroscopy (WP1). Then, advanced microstructural characterizations (XPS, HRTEM…) will be carried out to understand how plasma parameters in e-HiPIMS can affect the conformity and microstructure of capacitive titanium nitride and pseudo-capacitive vanadium oxynitride coatings on complex 3D microstructured Si substrates (WP2 and WP3). Finally, these 3D and nanostructured electrodes will be integrated and characterized as functional materials into micro-supercapacitors (WP4).