Highly flexible all-solid-state microsupercapacitors for on chip applications using a transfer-free fabrication process

Recent research efforts in flexible electronics focus on developing lightweight, thin, and flexible micro scale supercapacitor devices integratable on a chip as power source devices. The key requirements for such devices are high performance, 2D form factor, and compatibility with thin-chip technology. We report the fabrication of an ultra-thin flexible microsupercapacitor (fMSC) based on a highly aligned horizontal array of carbon nanotube (HACNT) sheet with in-plane interdigitated configuration using a facile, single-step and scalable fabrication process. The devices exhibited, excellent flexibility under various bending states, and outstanding bending durability up to 10,000 cycles under bending angle of 180 degrees. A representative fMSC with resolution of 40 mu m showed a high peak energy density of 54 mWh cm(-3). It was observed that the electrolyte deposition technique (drop-cast vs. spin-coating) affects the performance of fMSC devices. Drop-cast devices showed a higher specific capacitance (almost double) compared to spin-coated devices, but at the expense of flexibility. To demonstrate on-board integration, an array of these fMSCs was used as an energy storage unit in a vibrational energy-harvesting device, powered by a piezoelectric disk. This work demonstrates the potential of HACNT sheet based fMSCs with spin-coat electrolytes as ultra-thin microsupercapacitor devices for portable and wearable electronics.

Automated summary

Recent research efforts have focused on developing lightweight, thin, and flexible micro-scale supercapacitors for integration into chip power source devices. The ultra-thin flexible microsupercapacitors based on highly aligned horizontal array of carbon nanotubes exhibit excellent flexibility and outstanding bending durability. The electrolyte deposition technique affects the performance of the supercapacitors, with drop-cast devices showing higher specific capacitance but less flexibility compared to spin-coated devices.