Electrical double-layer capacitors

Fernando, Jayathu

doi:10.1016/b978-0-12-407947-2.00005-5

Cited by 4 publications

(3 citation statements)

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“…As shown in Figure 2, in the 1960s and early 1970s, power supplies were linear regulator designs having efficiencies in the range of 30-50% [2]. With the introduction of switching techniques in the 1980s, efficiency rose to 60-80%.…”

Section: Evolution Of Power Supply Design Technologymentioning

confidence: 99%

“…With the introduction of resonant converter techniques in the 1990s, this increased to 100 W/in 3 . When high-speed and power-hungry processors were introduced during the mid-1990s, much attention was focused on transient response, and industry trends were to mix linear and switching systems to obtain the best of both technologies [2]. Low-dropout (LDO) regulators were introduced in 1977 to power noisesensitive and fast transient loads in many portable applications [4].…”

Section: Evolution Of Power Supply Design Technologymentioning

confidence: 99%

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Current Context and Research Trends in Linear DC–DC Converters

et al. 2022

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With the introduction of switch-mode power supplies (SMPS) in the mid-1970s, the efficiency of DC–DC conversion rose from 60 to 80% and SMPS became a popular power supply solution. However, linear regulators have not become obsolete. The modern power management system in portable devices supports a complex mix of DC–DC converters, combining switch-mode power supplies (SMPS), switched capacitor converters (SCCs), and linear regulators in the form of low-dropout regulators (LDOs). LDOs are used to supply low-voltage DC power rails with very low noise and high current slew rate capability, which are usually fed by the output rail of SMPS. This paper provides a comprehensive review of the evolution of the application scope of linear-type DC–DC converters in the power supply context and the present research trends. First, we review the context of linear DC–DC converters in detail, particularly in portable device power supplies. Then, the details of LDO regulators and their recent industry development and research trends are discussed. Then, the discussion focuses on supercapacitor-assisted low-dropout (SCALDO) regulator design and its scope in the portable device power management together with SCALDO-based dual output and reduced switch designs, and finally, the conclusions follow.

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Section: Evolution Of Power Supply Design Technologymentioning

confidence: 99%

Section: Evolution Of Power Supply Design Technologymentioning

confidence: 99%

Current Context and Research Trends in Linear DC–DC Converters

et al. 2022

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“…Polyacrylonitrile (PAN), a thermoplastic polymer with the formula (C3H3N)n, is a synthetic precursor used to produce activated carbon fibers (Figure 7) [14,44]. PAN precursor fibers cost around $7 -$8 per kilogram, whereas textile PAN-based precursor fibers cost approximately $2 -$3 per kilogram [60] .…”

Section: Pan (Polyacrylonitrile) Fibermentioning

confidence: 99%

Binder-free textile PAN-based electrodes for aqueous and glycerol-based electrochemical supercapacitors

Barbosa

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Amidst different types of energy storage devices, electrochemical supercapacitors have received considerable attention as they close the gap between electrolytic capacitors and batteries. This work addresses electric double-layer capacitors (EDLCs), a type of electrochemical supercapacitor, and has been divided into two parts. In the former, the production and characterization of activated carbon fiber-felt (ACFF) electrodes derived from textile PAN-based fiber have been provided. In the latter, the electrochemical characterization of EDLCs in aqueous electrolytes (acidic and alkaline) and in three types of glycerol-based electrolytes have been investigated. Binder-free ACFF electrodes have a high specific surface area of 1875 m 2 g -1 , containing 87% of the total volume of pores as micropores (maximum pore width of 3 nm), and a modal distribution of 1.2 nm.Electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic chargedischarge techniques were carried out in a symmetric two-electrode setup at room temperature. The results showed that ACFF electrodes are suitable for acidic and alkaline aqueous electrolytes as well as the choline chloride-glycerol hybrid electrolyte (ChCl:GLY) at a molar ratio of 3:1. Among aqueous electrolytes, H2SO4 2 mol L -1 had the most satisfactory electrochemical performance in terms of power and energy, followed by KOH 2 mol L -1 and H2SO4 1 mol L -1 . Among the glycerol-based electrolytes investigated in this work, ChCl:GLY (3:1) has the most comparable performance to aqueous electrolytes. Although power density is still limited due to high internal resistance, ChCl:GLY (3:1) is heat-resistant and a promising alternative electrolyte for supercapacitors applications, especially given that glycerol is a by-product of FAME (fatty acid methyl ester) biodiesel.

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