Shape Evolution of Indium Sulfide Heterostructures via Carbon Nanotube Scrambling: Towards Reliable Sustainability and Mitigating Leakage Current in Supercapacitors  
[PERSON]  
1 Department of Electronics Engineering, Incheon National University, Incheon 22012, Republic of Korea 11 Department of Electronics Engineering, Incheon National University, Incheon 22012, Republic of Korea 11 Department of Physics, Yeungnam University, Gyeongan 38541, Republic of Korea 1  
[PERSON]  
1 Department of Electronics Engineering, Incheon National University, Incheon 22012, Republic of Korea 11 Department of Electronics Engineering, Incheon National University, Incheon 22012, Republic of Korea 11 Department of Physics, Yeungnam University, Gyeongan 38541, Republic of Korea 1  
[PERSON]  
1 Department of Electronics Engineering, Incheon National University, Incheon 22012, Republic of Korea 11 Department of Physics, Yeungnam University, Gyeongan 38541, Republic of Korea 11 Department of Electronics Engineering, Incheon National University, Incheon 22012, Republic of Korea 11 Department of Physics, Yeungnam University, Gyeongan 385  
structure due to a spinel defect, bandgap (2.0-2.3 eV), mechanical stability (up to 1027 K), high electrical/ionic conductivity, and a steady nature above 420 \({}^{\circ}\)C [5; 6; 7]. However, the thin-layered structure, low out-of-plane conductivity, limitations of the ion-diffusion process, and its tendency towards agglomeration restacking during operation might be the major reason for the limited exploration towards its practical utility. Due to its excellent optical and electrical properties, chemical stability, and high theoretical capacitance, In\({}_{2}\)S\({}_{3}\) (\(\alpha\)-In\({}_{2}\)S\({}_{3}\), \(\beta\)-In\({}_{2}\)S\({}_{3}\), and \(\gamma\)-In\({}_{2}\)S\({}_{3}\)) is an excellent choice for various applications such as gas sensors, photocatalysts, lithium-ion batteries, and supercapacitors [8; 9]. Among them, \(\beta\)-In\({}_{2}\)S\({}_{3}\) is one of the most appropriate candidates for SC electrode materials due to its unique structures and excellent physical properties, making it interesting from a scientific perspective [10]. However, the challenging aspects of In\({}_{2}\)S\({}_{3}\) lie in the intricacies involved in achieving a layered nanostructure, leading to the formation of a low-dimensional feature of materials, especially via hydro/solvothermal growth, due to self-agglomeration. Recently, our group reported a 2D-layered, sponge-like In\({}_{2}\)S\({}_{3}\) for the first time via a one-pot solvothermal growth method for supercapacitor application [11]. However, it falls short of long-term cyclic performance owing to limited ion diffusion and innate material characteristics. In this framework, single-walled carbon nanotubes (SWNTs) have several properties that make them attractive for use in supercapacitor electrodes, including a high surface area, high electrical conductivity, and good chemical stability. These properties can lead to improved performance and longer lifetimes for supercapacitors. A conventional approach is the combination of SWNT and transition metal sulfides (TMS) for optimal utilization as electrode materials for supercapacitors. This is a rapidly evolving field and new developments are being made constantly, with the goal of achieving higher energy density, better stability and longer lifetimes, and lower costs. Furthermore, self-discharge (SD) is a common issue in SCs, leading to reduced performance and lifespan [12; 13]. SD can be minimized by optimizing materials and designs to reduce internal leakage currents. Here, we report the use of the in situ growth of indium sulfide/SWNT heterostructures on nickel foam substrates to improve electrochemical performance and mitigate leakage current, reducing the SD rate. This study also investigates the SD mechanisms and voltage holding time (VHT) for the practical application of fabricated symmetric supercapacitors. Overall, the charge/discharge phenomena are controlled by potential and diffusion.