Laser‐Induced Transient Self‐Organization of TiN x Nano‐Filament Percolated Networks for High Performance Surface‐Mountable Filter Capacitors

Filter capacitors (FCs) are substantial for digital circuits and microelectronic devices, and thus more compact FCs are eternally demanded for system miniaturization. Even though microsupercapacitors are broadly regarded as an excellent candidate for future FCs, yet due to the limitation of available electrode materials, the capacitive performance of reported MSCs drops sharply under high-frequency alternating current. Herein, we present a unique laser-induced transient self-organization strategy, which synergizes pulsed laser energy and multi-physical field controlled coalescence processes, leading to the rapid and controllable preparation of titanium nitride ultrafine nano-filaments (diameter ≈3-5 nm) networks. Their chaotic fractal nanoporous structure, superior specific surface area, and excellent conductivity render these nanostructures promising candidates for FCs. Surface-mounted filter capacitors based on this electrode material exhibit ultra-long cycle-life (2 000 000 cycles) with record ultrahigh volumetric energy density of 9.17 mWh cm^-3 at 120 Hz in aqueous electrolyte, displaying advantages in function, size, and integrability compared with the state-of-the-art aluminum electrolytic capacitors. The method here provides a versatile toolbox for designing novel nanostructures with intriguing characteristics and insights for developing advanced and miniaturized filter and power devices.