Shape Evolution of Indium Sulfide Heterostructures via Carbon Nanotube Scrambling: Towards Reliable Sustainability and Mitigating Leakage Current in Supercapacitors

Abstract

For sustainable energy storage devices with long-term endurance, exploring novel electrode materials can be a realistic focus in the areas of robust structures, surface area control, high channel conductivity, and others. A composite of a hierarchical series of single-walled carbon nanotubes (SWNTs) with In2S3 was synthesized by applying a simple one-step solvothermal method. A SWNT scaffold yields a good conductive pathway, leading to the improved electron transportation and catalytic behaviors. This promotes the robust formation of materials and their enhancement in surface activity and specific capacitance. Herein, the nucleated nanocomposites based on SWNT-mediated In2S3 improve the specific capacitance (1268 F·g−1 at 10 mVs−1) to a remarkable 92.4% of its capacitance even after 10,000 cycles, and furthermore, the robust cocoon-like structure of INS5 (5 mL SWNT doped in In2S3) shows an excellent 97.8% of cyclic retention (10,000 cycles). As a conceptual demonstration of system integration, the as-fabricated symmetric supercapacitor (SSC) device is successfully integrated into the Bluetooth/photoplethysmography (BLE/PPG) module for a wireless sensor network. These findings, through indium sulfides with SWNT scrambling, are expected to contribute to the next-generation solid-state-supercapacitor (SSC)-integrated module in the wireless health monitoring system.