A Highly Stretchable Microsupercapacitor Using Laser‐Induced Graphene/NiO/Co₃O₄ Electrodes on a Biodegradable Waterborne Polyurethane Substrate

Abstract

Constructing microsupercapacitors (MSCs) with an outstanding stretchability is urgent for wearable electronics, and an intrinsic biodegradability is also meaningful. Herein, laser‐induced graphene/NiO/Co3O4 (NiO/Co3O4/LIG) is in situ synthesized on a polyimide (PI) film during laser processing, then the electrodes are transferred to a biodegradable waterborne polyurethane (WPU) substrate to fabricate stretchable MSCs. Experimentally, the as‐prepared stretchable MSCs exhibit an excellent areal capacitance of 2.4 mF cm−2, high capacitance retention of 77.1% at 50% strain, and capacitance degradation of less than 19.8% after 1000 stretching cycles. These desirable properties are mainly attributed to the gradient structure of NiO/Co3O4/LIG, the synergistic effect of hybrid NiO/Co3O4 nanoparticles, and the intensive interface adhesion between the electrodes and WPU. Interestingly, the robust function of stretchable MSCs is further presented by using them to power a microsensor and assembling them with triboelectric nanogenerators to generate power from mechanical contact with skin, which makes the stretchable MSCs promising as a sustainable driving source for wearable electronics.

Recent Progress in Graphene‐Based Microsupercapacitors

“…The MSC shows 2.4 mF cm −2 of areal capacitance and 77.1% of capacitance retention under 50% strain. [ 167 ] Plasma‐reduced nitrogen‐doped graphene oxide (PNG)||PNG–MoO 2 ‐based asymmetric MSCs is fabricated by laser technique. The fine nanoparticles of MoO 2 are embedded on the nitrogen‐doped graphene nanosheets with 8.05% of nitrogen.…”

Laser‐Induced Graphene/MoO2 Core‐Shell Electrodes on Carbon Cloth for Integrated, High‐Voltage, and In‐Planar Microsupercapacitors

“…Therefore, upon specific modifications, using thinner CC, and/or optimizing laser parameters, it is possible to adjust the quality of LIG and induce MoO 2 /LIG hybrid electrodes with different morphologies. [44,45]…”

Laser fabrication of functional micro-supercapacitors

“…In this regard, Wang et al in-situ synthesized derived graphene/NiO/ Co 3 O 4 (NiO/Co 3 O 4 /LIG) microelectrodes through carbonization and oxidation of gelatin/Ni/Co layer on the PI film with laser (Fig. 13f) [215]. The stretchable pseudocapacitive MSCs were readily obtained after transferring the microelectrodes onto a biodegradable waterborne polyurethane (WPU) substrate via a simple casting-and-peeling process.…”

“…According to the laser technology in processing diversified micro-electrodes, the developed MSCs are easily integrated with other energy-related devices in widespread fields, showing great potential in practical intelligent application [215,231]. At present, laser-fabricated MSCs have been widely used in solar cells, photodetectors, sensors and generators [232].…”