Cobalt-titanium-oxide-functionalized cotton fabric for enhanced energy storage in supercapacitors and efficient energy harvesting in piezoelectric nanogenerators

초록

Cobalt-titanium oxide (CTO)@conductive flexible carbon/nitrogen-based supercapacitors deliver stable and superior electrochemical performance. CTO-functionalized cotton fabric was prepared via wet impregnation, the duration of which modulated the morphology of the CTO rods. Carbonization transformed the cotton fabric into a conductive flexible carbon/nitrogen substrate, while the CTO rods retained their morphology. The optimal electrode, having a wet impregnation duration of 16 h, had a high areal capacitance of 2.3 F cm(-2), a capacitance retention of 85 % after 10,000 cycles, and a high energy density of 980 mu W h cm(-2) at a power density of 3200 mu W cm(-2), demonstrating its potential for rapid energy storage and release. Additionally, the CTO-functionalized cotton fabric was immersed in a polyvinylidene fluoride (PVDF) solution and used to fabricate a piezoelectric nanogenerator (PENG), demonstrating a second functional application of the material. The PVDF/CTO@cotton fabric-based PENG had a piezopotential of 7 V under an applied force of 20 N and generated a voltage of similar to 5 V by harvesting energy from biomechanical movements of grabbing a teapot.

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