MoS₂ decorated carbon fiber yarn hybrids for the development of freestanding flexible supercapacitors

Academic and industrial efforts have focused on developing energy storage devices for wearable and portable electronics using low-cost, scalable, and sustainable materials and approaches. In this work, commercially available stretch-broken carbon fiber yarns (SBCFYs) were hybridized with mixed phases of 1 T and 2H MoS2 nanosheets via conventional and microwave-assisted heating (CAH, MAH) without the use of binders to fabricate symmetric freestanding 1D fiber-shaped supercapacitors (FSCs). Electrochemical characterization performed in a three-electrode configuration showed promising results with specific capacitance values of 184.41 and 180.02 Fg(-1), at 1 mVs(-1) for CAH and MAH, respectively. Furthermore, after performing 3000 CV cycles at 100 mVs(-1), the capacitance retention was 79.5% and 95.7%, respectively. Using these results as a reference, symmetric 1D FSCs were fabricated by pairing hybridized SBCFYs with MoS2 by MAH. The devices exhibited specific capacitances of approximately 58.60 +/- 3.06 Fg(-1) at 1 mVs(-1) and 54.81 +/- 7.34 Fg(-1) at 0.2 Ag(-1) with the highest power density achieved being 15.17 Wg(-1) and energy density of 5.06x10(-4 )Whg(-1). In addition, five 1D FSCs were hand-stitched and connected in series onto a cotton fabric. These supercapacitors could power a temperature and humidity sensor for up to six minutes, demonstrating the practicality and versatility of the prepared 1D FSCs for powering future electronic systems.