A second strategy consisted in the preparation of flexible micro-supercapacitors via laser-writing of commercial RuO2 on polyimide substrate. Indeed, laser-writing provides facile and scalable engineering with low cost (7), as less than 1 mg.cm-2 of active material are needed in micro-electrodes. Thus, RuO2 interdigitated electrodes were obtained from laser-writing of a precursor mixture of commercial RuO2.xH2O powder and HAuCl4.3H2O salt, spin-coated onto KaptonTM. Laser-writing led to current collector-free and mechanically stable flexible interdigitated RuO2 electrodes. Capacitance values of ~ 30 mF.cm-2 were recorded at 20 mV.s-1 in 1M H2SO4 for the flexible device. This work open the way for the design of high performance micro-devices at large scale.
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