China
Africa
Explore chapters and articles related to this topic
Graphene and Its Composite for Supercapacitor Applications
Published in Amir Al-Ahmed, Inamuddin, Graphene from Natural Sources, 2023
Priyadharshini Madheswaran, Pazhanivel Thangavelu
An ultracapacitor is a device which can store charges via two types of mechanisms such as (i) electric double layer capacitance (EDLC) and (ii) pseudocapacitance. Based on the material, either one or both the types of mechanisms were used to store charges. The commonly used electrode materials for the EDLC type are carbon-based materials like activated carbon, graphene, carbon nanotubes [7]. On the other hand, pseudocapacitance electrodes make use of metal oxides, sulphides and conducting polymers. However, the electrode materials still cannot meet the requirement of day-to-day applications. Hence, hybrid electrode materials comprising both the EDLC and redox behaviour with rational optimization and design are expected to meet the requirements of modern society[7,8].
Supercapacitors, Batteries, Fuel Cells, and Related Applications
Published in Antonio Doménech-Carbó, Electrochemistry of Porous Materials, 2021
Pseudocapacitance responses are characterized by voltammetric features diverging from the square signals as in Figure 10.2. Pseudocapacitance arises from fast, reversible Faradaic reactions occurring at or near a solid electrode surface over an appropriate range of potential. Such redox reactions can go beyond the surface area and penetrate the bulk of these materials [3,5]. Noble metal oxides such as RuO2 and IrO2 provide the most specific capacitance values (around 750 F g–1) but they are toxic and expensive. Then, porous transition metal oxides such as CoOx, NiOx, and MnO2 are currently under intensive research as materials for supercapacitors. The surface Faradaic reactions for NiO are generally described in terms of the processes [17]: NiO+OH−→NiOOH+e−
Influence of Cationic, Anionic, and Nonionic Surfactants on Hydrothermal Synthesis of Nano Cus: Structural, Morphological, and Capacitance Behavior
Published in Jose James, Sabu Thomas, Nandakumar Kalarikkal, Yang Weimin, Kaushik Pal, Processing and Characterization of Multicomponent Polymer Systems, 2019
D. Geetha, P.S. Ramesh, Surekha Podili
Due to the unique property such as its electrical conductivity [22] resembling metals and absorption of solar energy [23] of sulfides, they have numerous potential applications. Many researchers focused on the preparation of CuS with different morphology [24, 25]. Surfactants are usually used in reaction systems and they play critical roles in the morphological control of CuS nanostructures. Inorganic nanomaterials are well-defined morphologies having peculiar properties and potential applications Viz., sensors, energy storage and energy conversion [26]. CuS has attracted significant attention as an active electrode material owing to its high theoretical specific capacitance, excellent reversibility, good electrical conductivity and environmental friendliness [27]. For practical application of high power density devices, the powder forms yield better volumetric energy density thin films. CuS powders of various morphologies have been synthesized by different routes, and their utility as electrode materials for pseudocapacitor has been reported [28]. It is well accepted that pseudocapacitance is an interfacial phenomenon which is tightly related to the specific surface area and porous structure of active electrode materials. The mesoporous sulfide system can provide a very short diffusion pathway for ion as well as high specific surface area, leading to improved electrochemical performance.
Synthesis of highly self-dual-doped O, P carbon nanosheets derived from banana stem fiber for high-performance supercapacitor electrode
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Erman Taer, Novi Yanti, Dinda Putri Azaria, Apriwandi Apriwandi, Rika Taslim, Dahyunir Dahlan
In this work, AC-BSF nanosheets enriched with self-dual-doped O and P were successfully synthesized through the chemical activation of 0.5 M KOH via integrated pyrolysis (N2-CO2) at temperatures up to 850°C. The utilization of eco-friendly, cost-effective, and sustainable green electrode material derived from banana stem fiber exhibited remarkable electrochemical performance for supercapacitor applications. The synergistic effect of KOH/N2-CO2 at high temperatures produced a porous activated carbon material with amorphous porosity and high hydrophilicity and also increased the content of self-dual-doped heteroatoms O and P within the activated carbon material. This process involved redox reactions during electrochemical processes and led to the development of pseudocapacitance properties. The carbon purity reached 69.56%, with a surface area of 326.35 m2/g, and the optimal combination of micro-meso pores contributed positively to the ABSF electrode. Notably, the BSF AC electrode in 1 M H2SO4 aqueous electrolyte achieved a specific energy density and power of 31.13 Wh/kg and 150.31 W/kg, respectively. The synergistic combination of the mutually beneficial physical properties of the electrodes produced an extraordinary specific capacitance of 206.76 F/g. These results highlighted the potential of preparing AC nanosheets with high self-dual-doped O and P from banana stem fiber waste as promising electrodes for supercapacitors, enabling high-energy storage devices.
Electrochemical performance of binder-free Ni(OH)2/RGO battery type electrode materials for supercapacitor
Published in International Journal of Green Energy, 2023
Yusuf Khan, Akanksha R. Urade, Amrita De Adhikari, Palash Chandra Maity, K. Ramesh, Shahid Bashir, Indranil Lahiri, S. Ramesh
In recent times, the swing toward alternate energy sources is crucial, owing to the rapid depletion of nonrenewable energy sources leading to global warming. As a result, alternative energy resources and energy harvesting and storage devices have become attractive interests of ongoing research (Arico et al. 2011; Bansal et al. 2018; Brisse et al. 2018; Guo, Hu, and Wan 2008; Khaleed et al. 2016). Supercapacitors (SCs) are energy storage devices having excellent potential for application in a myriad of products like all-electric and hybrid cars, two-wheelers, renewable energy sources for stationary applications, solid-state memory, etc. SCs have superior power and energy density than batteries and conventional capacitors (Liu, Wang, and Yan 2015). In addition to this, SCs also have other favorable properties like longer charge-discharge cycle life, low internal resistance, and low cost. SCs are classified into two categories based on the charge storage mechanism, i.e., electric double-layer capacitor (EDLC) and pseudocapacitors (Barzegar et al. 2016; Jiang et al. 2015). Pseudocapacitors store energy on the surface of the electrodes using reversible redox reactions, allowing better capacitance and energy density. Faradaic pseudocapacitance shows static double-layer capacitance, which in addition to double-layer capacitance increases the overall capacitance. The peak current (i) response of pseudocapacitive material will show linear current response dependency on the scan rate (i vs v) with very small redox peaks in cyclic voltammetry (Gogotsi and Penner 2018).
KOH-assisted synthesis of oxygen-rich activated carbon derived from biomass sugar palm midrib as performance electrode cell supercapacitor
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Rakhmawati Farma, Haliza Putri, Irma Apriyani
Figure 4 shows the constituent elements of the SPM with the highest percentage weight and atoms. The purity of the carbon element is caused by the chemical activation process, carbonization, and physical activation to degrade and evaporate lignocellulosic compounds on the SPM electrode. Also, oxygen is the constituent element of the electrode with the highest percentage of weight and atoms after carbon. The oxygen in the carbon electrode comes from the basic constituents of sugar palm midrib biomass, KOH impregnation, and oxidation at high temperatures. The addition of the KOH percentage from 5% to 10% caused the KOH impregnation to occur in a complex manner. This produced elemental oxygen with the highest atomic and weight percentages of 21.91% and 19.12%, respectively, for the SPM-10 sample. Furthermore, the addition of a KOH percentage of more than 10% caused the impregnation of KOH and carbon electrodes to occur excessively. This decreased the weight and atomic percentages of elemental oxygen to 21.20% and 18.14%, respectively, for the SPM-15 sample. The presence of oxygen increases the wettability of the electrolyte and assists redox reactions in aqueous solutions. This provides stable pseudo capacitance through faradic charge transfer reactions, hence the electrochemical cell is pseudocapacitance (Chen et al. 2019). The potassium element on the electrode comes from the KOH impregnation process during the chemical activation at 80°C. Meanwhile, magnesium, calcium, and silica are the basic constituents of sugar palm midrib biomass, which are not decomposed in a complex manner in the chemical activation, carbonization, and physical activation processes with a small percentage.