scholarly journals Bamboo-Based Mesoporous Activated Carbon for High-Power-Density Electric Double-Layer Capacitors

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2750
Author(s):  
Ju-Hwan Kim ◽  
Hye-Min Lee ◽  
Sang-Chul Jung ◽  
Dong-Chul Chung ◽  
Byung-Joo Kim
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Specific Surface ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Electrode Material ◽  
Electric Double Layer ◽  
Mesoporous Activated Carbon ◽  
Double Layer Capacitors

Demand for hybrid energy storage systems is growing, but electric double-layer capacitors (EDLCs) have insufficient output characteristics because of the microporous structure of the activated carbon electrode material. Commercially, activated carbon is prepared from coconut shells, which yield an activated carbon material (YP-50F) rich in micropores, whereas mesopores are desired in EDLCs. In this study, we prepared mesoporous activated carbon (PB-AC) using a readily available, environmentally friendly resource: bamboo. Crucially, modification using phosphoric acid and steam activation was carried out, which enabled the tuning of the crystal structure and the pore characteristics of the product. The structural characteristics and textural properties of the PB-AC were determined, and the specific surface area and mesopore volume ratio of the PB-AC product were 960–2700 m2/g and 7.5–44.5%, respectively. The high specific surface area and mesopore-rich nature originate from the phosphoric acid treatment. Finally, PB-AC was used as the electrode material in EDLCs, and the specific capacitance was found to be 86.7 F/g for the phosphoric-acid-treated sample steam activated at 900 °C for 60 min; this capacitance is 35% better than that of the commercial YP-50F (64.2 F/g), indicating that bamboo is a suitable material for the production of activated carbon.

Electrochemical Properties of Supercapacitors Using Boron Nitrogen Double-Doped Carbon Nanotubes as Conductive Additive

NANO ◽  
2019 ◽  
Vol 14 (07) ◽  
pp. 1950080
Author(s):  
Hao Hu ◽  
Xiaogang Sun ◽  
Wei Chen ◽  
Jie Wang ◽  
Xu Li ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Electric Double Layer ◽  
X Ray ◽  
Nitrogen Doped ◽  
Conductive Additive ◽  
Double Layer Capacitors ◽  
Boron Nitrogen

Carbon nanotubes (CNTs) were doped by ammonium borate as the sources of nitrogen and boron. Under the protection of Ar gas, boron-nitrogen doped CNTs were prepared through nitriding and boronization at high temperature. It is a conductive additive. Then, the obtained CNTs were mixed with activated carbon (AC), SP, sodium dodecyl sulfate (SDS), and cellulose fiber to prepare electrodes. With all the materials, a symmetric electric double-layer supercapacitor (EDLC) was assembled. Next, the materials and electrodes were also characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The factors, chemical connections, and specific surface area of the CNTs were analyzed by X-ray energy spectrum analysis (EDS), X-ray photoelectron spectroscopy (XPS), as well as a specific surface area and porosimetry analyzer (BET). In addition, the electrochemical performances of electric double-layer capacitors were tested with the help of cyclic voltammetry, constant-current charging and discharging, and so on. From the results, we can make a conclusion, that is, both B and N atoms were added into the CNTs and formed bonds successfully with carbon atoms mutually. Besides, the specific surface area is about 1.5 times than that of the CNT. When the charge/discharge current density reaches 50[Formula: see text]mA/g, we can find that the mass specific capacitance of the capacitor can run up to 32.19[Formula: see text]F/g. Also, we observe that the maximum power density is close to 220[Formula: see text]W/kg (700[Formula: see text]mA/g), and the energy density can arrive 9.31[Formula: see text]Wh/kg (50[Formula: see text]mA/g). Based on the impedance test, the electrodes are characterized with low impedance. After 2000 cycles, the boron-nitrogen doped double-layer capacitors maintain a capacitance retention ratio of above 95%. Its power density can still achieve 220[Formula: see text]W/kg when the energy density keeps at 3.46[Formula: see text]Wh/kg. In other words, the electrochemical performance functions of the electric double-layer capacitors are enhanced while the CNTs serve as the electrodes.

scholarly journals Application of Porous Carbon Material As Electrode Material of Polyvalent Cation Electric Double Layer Capacitor (EDLC) for High Capacity

2020 ◽  
Author(s):  
Tsubasa Okamura ◽  
Kiyoharu Nakagawa
Keyword(s):  
Energy Density ◽  
Specific Surface ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Electrode Material ◽  
Electric Double Layer ◽  
Electrode Materials ◽  
Power Supplies ◽  
Adsorption And Desorption

Electric double layer capacitors (EDLC) are charged and discharged by the physical adsorption and desorption of electrolyte ions on the electrode surface. EDLC has the advantages of high-speed charge and discharge and long life. EDLC is used in memory backup power supplies such as personal computers and energy regenerative systems for power regenerative brakes in hybrid vehicles. In recent years, demand for applications such as in-vehicle power supplies has increased. Therefore, high energy density is required. The energy density increases by increasing the electrostatic capacity and the potential. In the conventional adsorption and desorption of monovalent cations, only one electron can be exchanged for each cation. In adsorption and desorption, two electrons can be exchanged for each cation. Therefore, it was considered that the capacitance can be increased by using an electrolyte of divalent cations.In this study, Ca2+ was used as the divalent cation. As an organic electrolyte, propylene carbonate (PC) and γ-butyrolactone (GBL), which are commonly used in EDLC research as a solvent and can dissolve the electrolyte used. In addition, the dependence of the specific surface area and pore characteristics of the electrode material on the capacity was examined. Activated carbon and carbon gel were used as electrode materials. The capacitance of Ca2+ electrolyte increased when GBL was used as the solvent. Capacitance increased depending on the specific surface area of electrode materials.

Mesoporous Activated Carbon Filaments

1996 ◽  
Vol 454 ◽  
Author(s):  
Weiming Lu ◽  
D. D. L. Chung
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mesoporous Activated Carbon ◽  
Carbon Filaments

ABSTRACTActivated carbon filaments of diameter ∼0.1 μm, main pore size (BJH) 55 Å, specific surface area 1310 m2/g and yield 36.2% were obtained by activating carbon filaments of diameter ∼ 0.1 urn in C02 + N2 (1:1) at 970°C for 80 min. Prior to this activation, the filaments were surface oxidized by exposure to ozone.

Modified polyacrylonitrile-based activated carbon fibers applied in supercapacitor

2016 ◽  
Vol 45 (3) ◽  
pp. 164-171 ◽  
Author(s):  
Linjie Su ◽  
Bohong Li ◽  
Dongyu Zhao ◽  
Chuanli Qin ◽  
Zheng Jin
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
Electrode Material ◽  
High Specific Capacitance ◽  
Activated Carbon Fibers ◽  
Content Type

Purpose The purpose of this paper is to prepare a new modified activated carbon fibers (ACFs) of high specific capacitance used for electrode material of supercapacitor. Design/methodology/approach In this study, the specific capacitance of ACF was significantly increased by using the phenolic resin microspheres and melamine as modifiers to prepare modified PAN-based activated carbon fibers (MACFs) via electrospinning, pre-oxidation and carbonization. The symmetrical supercapacitor (using MACF as electrode) and hybrid supercapacitor (using MACF and activated carbon as electrodes) were tested in term of electrochemical properties by cyclic voltammetry, AC impedance and cycle stability test. Findings It was found that the specific capacitance value of the modified fibers were increased to 167 Fg-1 by adding modifiers (i.e. 20 wt.% microspheres and 15 wt.% melamine) compared to that of unmodified fibers (86.17 Fg-1). Specific capacitance of modified electrode material had little degradation over 10,000 cycles. This result can be attributed to that the modifiers embedded into the fibers changed the original morphology and enhanced the specific surface area of the fibers. Originality/value The modified ACFs in our study had high specific surface area and significantly high specific capacitance, which can be applied as efficient and environmental absorbent, and advanced electrode material of supercapacitor.

scholarly journals Sago Waste Based Activated Carbon Film as an Electrode Material for Electric Double Layer Capacitor

2010 ◽  
Vol 4 (1) ◽  
pp. 117-124 ◽  
Author(s):  
H. Aripin ◽  
L. Lestari ◽  
D. Ismail ◽  
S. Sabchevski
Keyword(s):  
Activated Carbon ◽  
Double Layer ◽  
Electrode Material ◽  
Electric Double Layer ◽  
Specific Capacity ◽  
Carbon Film ◽  
Electrochemical Characteristics ◽  
Double Layer Capacitor ◽  
Sago Waste ◽  
Double Layer Capacitors

In this feasibility study a novel prospective electrode material for electric double layer capacitors (EDLC) has been investigated. This promising material is activated carbon (AC) film produced using sago waste as a precursor. Important parameters of the technological process are the KOH to charcoal ratio and the content of the polytetrafluoroethylene (PTFE) binder. The influence of these parameters on the microtexture and pore structure and on the electrochemical characteristics of the AC films has been studied in detail. The measured specific surface area (SSA) of the samples is in the range from 212 to 1498 m2/g. It has been found that the presence of micropores increases the specific capacity while the presence of the mesopores acts in the opposite direction, because these mesopores are too wide in diameter for aqueous electrolyte. The specific capacitance of the studied samples has been found to be in the range from 16 to 64 F/g.

Sign in / Sign up

Export Citation Format

Share Document