A band-aid-based MoSe2/Nb2C wearable supercapacitor for integrated ammonium-ion energy storage and real-time pressure monitoring

Abstract

The market for wearable electronic devices is rapidly growing, with increasing potential for future development. Researchers around the globe are striving to enhance these devices, focusing on achieving a balance between functionality and wearability to drive commercialization. Supercapacitors are regarded as one of the most promising energy storage technologies, bridging the gap between conventional batteries and dielectric capacitors to support high-power applications. This study presents the hybrid supercapacitor application of molybdenum sulfide, molybdenum selenide, and niobium carbide on band-aid-based wearable electrodes tested in three different electrolytes (sodium sulfate, ammonium sulfate, and zinc sulfate). Among the three electrolytes, the ammonium sulfate electrolyte exhibited exceptional electrochemical performance, including high specific capacitance, excellent power density, and remarkable cycling stability. Band-aid-based wearable ammonium ion hybrid supercapacitors were designed to explore their real-time applicability, utilizing activated carbon as the negative electrode and molybdenum selenide/niobium carbide as the positive electrode. The fabricated ammonium ion hybrid supercapacitor offers a maximum specific capacitance of 120 F g⁻¹ with 92% capacitance retention after 20 000 cycles. Also, it exhibits an outstanding energy density and power density. This suggested multipurpose integrated system opens new possibilities for creating flexible and adaptive wearable electronics. A glucose sensor is shown to be powered by the fabricated ammonium ion hybrid supercapacitor. The molybdenum selenide/niobium carbide-coated band-aid is also sandwiched between tiny layers of copper foil to create a pressure sensor. It is powered by an ammonium ion hybrid supercapacitor, which enables precise and steady real-time monitoring of the radial pulse pressure on the wrist of a person. This work creates new opportunities to explore the potential of wearable technology and nanomaterials to develop self-sufficient, cost-effective healthcare systems for monitoring health parameters in real-time.