Rapid Joule-heating synthesis of oxide nanoparticles on carbon cloth as electrodes for supercapacitors

The rapid and controllable incorporation of pseudocapacitive materials onto the carbon cloth (CC) holds great promise for wearable supercapacitor devices. However, efficiently activating CC and achieving a high mass loading of electroactive materials remain challenging with conventional synthetic methods, which involve complex treatment and prolonged heating. This work presents a universal two-step strategy for the rapid preliminary activation of CC (PACC) and synthesis of composites using ultrafast high-temperature thermal shock (HTS) for CC/oxides-based electrodes. Pre-treated CC loaded with precursor materials is exposed to temperatures that rise swiftly to 1000 °C within 200 ms. Three electrical pulses, each lasting 100 ms, are applied and the entire process takes approximately 10 s. As a proof-of-concept, we synthesize a PACC/Co 3 O 4 electrode material, which delivers a high specific capacity of 408 mF cm −2 at 0.2 mA cm −2 , 97 % capacity retention at 2 mA cm −2 , and excellent stability after 20,000 cycles. The flexible supercapacitor based on PACC/Co 3 O 4 electrodes deliveres a high capacity and stable performance at various bending states. Moreover, our HTS method can be extended to other transition metal oxide (TMO) incorporated with the activated CC. The facile and efficient method paves the way for the synthesis of various CC-based supercapacitor materials.