Asymmetric supercapacitors based on carbon nanofibre and polypyrrole/nanocellulose composite electrodes

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16405-16413 ◽  
Author(s):  
Petter Tammela ◽  
Zhaohui Wang ◽  
Sara Frykstrand ◽  
Peng Zhang ◽  
Ida-Maria Sintorn ◽  
...  
Keyword(s):  
Current Density ◽  
Aqueous Electrolyte ◽  
Cell Voltage ◽  
Composite Electrodes ◽  
Asymmetric Supercapacitors ◽  
Carbon Nanofibre ◽  
Maximum Cell ◽  
A Current

Asymmetric, all-organic supercapacitors (containing an aqueous electrolyte), exhibiting a capacitance of 25 F g−1 (or 2.3 F cm−2) at a current density of 20 mA cm−2 and a maximum cell voltage of 1.6 V, are presented.

scholarly journals Electrochemical Features of Symmetric and Asymmetric Supercapacitors Based on Nanostructured Mn-Cuo Electrodes

2018 ◽  
Vol 34 (6) ◽  
pp. 3058-3063 ◽  
Author(s):  
R. Suresh ◽  
K. Tamilarasan ◽  
D. Senthil Vadivu
Keyword(s):  
Current Density ◽  
Material Science ◽  
Electrode Materials ◽  
Aqueous Electrolyte ◽  
Cyclic Stability ◽  
Initial Value ◽  
Asymmetric Supercapacitors ◽  
Supercapacitive Performance ◽  
Subsequent Investigation ◽  
A Current

Progress in material science has unearthed a number of options that offer great advantages for nanostructured electrode materials which enable supercapacitors to operate efficiently. Present work involves fabrication of symmetric and asymmetric type supercapacitor devices utilizing Mn-CuO nanostructures and activated carbon (AC) as electrode materials and subsequent investigation on their supercapacitive performance in 2M KOH aqueous electrolyte. The asymmetric supercapacitor device (Mn-CuO // 2M KOH// AC) demonstrate a specific capacitance of 72 Fg-1 at a current density of 0.5 Ag-1. The cyclic stability test of this device performed at a current density of 10 Ag-1 reveals a capacitance retention of 71% of its initial value over 300 charge-discharge cycles. In addition, this device exhibits an energy density of 7.4 Whkg-1 and a power density of 127 Wkg-1.

CO2 electrolysis to multicarbon products in strong acid

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. 1074-1078
Author(s):  
Jianan Erick Huang ◽  
Fengwang Li ◽  
Adnan Ozden ◽  
Armin Sedighian Rasouli ◽  
F. Pelayo García de Arquer ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Evolution ◽  
Current Density ◽  
Carbon Emissions ◽  
Active Sites ◽  
Cell Voltage ◽  
Strong Acid ◽  
Electrochemically Active ◽  
Co2 Electrolysis ◽  
A Current

Carbon dioxide electroreduction (CO2R) is being actively studied as a promising route to convert carbon emissions to valuable chemicals and fuels. However, the fraction of input CO2 that is productively reduced has typically been very low, <2% for multicarbon products; the balance reacts with hydroxide to form carbonate in both alkaline and neutral reactors. Acidic electrolytes would overcome this limitation, but hydrogen evolution has hitherto dominated under those conditions. We report that concentrating potassium cations in the vicinity of electrochemically active sites accelerates CO2 activation to enable efficient CO2R in acid. We achieve CO2R on copper at pH <1 with a single-pass CO2 utilization of 77%, including a conversion efficiency of 50% toward multicarbon products (ethylene, ethanol, and 1-propanol) at a current density of 1.2 amperes per square centimeter and a full-cell voltage of 4.2 volts.

Degradation of (La0.8Sr0.2)0.98MnO3−δ–Zr0.84Y0.16O2−γ composite electrodes during reversing current operation

2015 ◽  
Vol 182 ◽  
pp. 365-377 ◽  
Author(s):  
Gareth A. Hughes ◽  
Justin G. Railsback ◽  
Kyle J. Yakal-Kremski ◽  
Danielle M. Butts ◽  
Scott A. Barnett
Keyword(s):  
Current Density ◽  
Composite Electrodes ◽  
Electrode Structure ◽  
Ohmic Resistance ◽  
Impedance Response ◽  
Oxygen Electrodes ◽  
Current Cycle ◽  
Current Operation ◽  
Solid Oxide Cell ◽  
A Current

Reversing-current operation of solid oxide cell (La0.8Sr0.2)0.98MnO3−δ–Zr0.84Y0.16O2−γ (LSM–YSZ) oxygen electrodes is described. Degradation was characterized by impedance spectroscopy in symmetric cells tested at 800 °C in air with a symmetric current cycle with a period of 12 hours. No change in cell resistance could be detected, in 1000 h tests with a sensitivity of ∼1% per kh, at a current density of 0.5 A cm−2 corresponding to an overpotential of 0.18 V. At a current density to 0.6 A cm−2 (0.33 V overpotential) measurable resistance degradation at a rate of 3% per kh was observed, while higher current/overpotential values led to faster degradation. Degradation was observed mainly in the ohmic resistance for current densities of 0.6, 0.8 and 0.9 A cm−2, with little change in the polarization resistance. Polarization degradation, mainly observed at higher current density, was present as an increase in an impedance response at ∼30 kHz, apparently associated with the resistance of YSZ grain boundaries within the electrode. Microstructural and chemical analysis showed significant changes in electrode structure after the current cycling, including an increase in LSM particle size and a reduction in the amount of YSZ and LSM at the electrode/electrolyte interface – the latter presumably a precursor to delamination.

An advanced and highly efficient Ce assisted NiFe-LDH electrocatalyst for overall water splitting

2020 ◽  
Vol 4 (1) ◽  
pp. 312-323 ◽  
Author(s):  
Harsharaj S. Jadhav ◽  
Animesh Roy ◽  
Bezawit Z. Desalegan ◽  
Jeong Gil Seo
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Room Temperature ◽  
Cell Voltage ◽  
Highly Efficient ◽  
Overall Water Splitting ◽  
A Cell ◽  
A Current

A room-temperature synthesized NiFeCe2 electrocatalyst delivered a current density of 10 mA cm−2 at a cell voltage of 1.59 V when used as the electrolyzer.

scholarly journals High Temperature Water Electrolysis Using Metal Supported Solid Oxide Electrolyser Cells (SOEC)

2010 ◽  
Vol 72 ◽  
pp. 135-143 ◽  
Author(s):  
Günter Schiller ◽  
Asif Ansar ◽  
Olaf Patz
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Current Density ◽  
Degradation Rate ◽  
Cell Voltage ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Metallic Interconnect ◽  
A Current

Metal supported cells as developed at DLR for use as solid oxide fuel cells by applying plasma deposition technologies were investigated in operation of high temperature steam electrolysis. The cells consisted of a porous ferritic steel support, a diffusion barrier layer, a Ni/YSZ fuel electrode, a YSZ electrolyte and a LSCF oxygen electrode. During fuel cell and electrolysis operation the cells were electrochemically characterised by means of i-V characteristics and electrochemical impedance spectroscopy measurements including a long-term test over 2000 hours. The results of electrochemical performance and long-term durability tests of both single cells and single repeating units (cell including metallic interconnect) are reported. During electrolysis operation at an operating temperature of 850 °C a cell voltage of 1.28 V was achieved at a current density of -1.0 A cm-2; at 800 °C the cell voltage was 1.40 V at the same operating conditions. The impedance spectra revealed a significantly enhanced polarisation resistance during electrolysis operation compared to fuel cell operation which was mainly attributed to the hydrogen electrode. During a long-term test run of a single cell over 2000 hours a degradation rate of 3.2% per 1000 hours was observed for operation with steam content of 43% at 800 °C and a current density of -0.3 Acm-2. Testing of a single repeating unit proved that a good contacting of cell and metallic interconnect is of major importance to achieve good performance. A test run over nearly 1000 hours showed a remarkably low degradation rate.

Preparation of CMC-PVA/PAN-FePc(COOH)8/CS-PVA Bipolar Membrane and its Application in Electro-Oxidized Synthesis of Dialdehydle Starch

2015 ◽  
Vol 1120-1121 ◽  
pp. 141-147
Author(s):  
Zhong Gui Li ◽  
Ting Jin Zhou ◽  
Ri Yao Chen ◽  
Xiao Chen ◽  
Xi Zheng ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Current Efficiency ◽  
Current Density ◽  
Cell Voltage ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Experimental Results ◽  
Bipolar Membrane ◽  
Electrospinning Technique ◽  
A Current

The polyacrylonitrile (PAN)-iron octocarboxyphthalocyanine (FePc(COOH)8) nanofibers were prepared using electrospinning technique and introduced into the interlayer of a carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA)/chitosan (CS)-polyvinyl alcohol bipolar membrane (BPM), which was characterized using SEM, contact angle measurement, current-voltage characteristics, AC impedance spectroscopy and so on. The experimental results showed that after modification by PAN-FePc(COOH)8 nanofibers, the membrane impedance of the BPM and its cell voltage were decreased. That indicated that the water splitting efficiency in the interlayer of the BPM was increased. Then the prepared CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM was used in the electro-oxidized preparation of dialdehydle starch (DAS). The experimental results indicated that a current density of 20mA·cm-2 was suitable to obtain high current efficiency. When the electrolysis time was 3h at a current density of 20 mA·cm-2 , the current efficiency of the CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM-equipped cell was as high as 67%.

Construction of a MnCo2O4@NiyMx (S and P) crosslinked network for efficient electrocatalytic water splitting

CrystEngComm ◽  
2019 ◽  
Vol 21 (47) ◽  
pp. 7293-7302 ◽  
Author(s):  
Xiaoqiang Du ◽  
Jianpeng Fu ◽  
Xiaoshuang Zhang
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Cell Voltage ◽  
A Current

Using MnCo2O4@Ni3S2 as a bifunctional water splitting catalyst, an overpotential of ∼370 mV is obtained at a very low cell voltage of 1.60 V with a current density of 10 mA cm−2 in 1.0 M KOH.

Controllable synthesis of Cu–Ni–M (M = S, P and Se) hybrid nanoarrays for efficient water splitting reaction

2021 ◽  
Author(s):  
Nannan Chen ◽  
Yanhong Wang ◽  
Xiaoqiang Du ◽  
Xiaoshuang Zhang
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Cell Voltage ◽  
Controllable Synthesis ◽  
A Cell ◽  
A Current

The results demonstrate that Cu–Ni–S/NF//Cu–Ni–P/NF pairs show superior water splitting performance with only requiring a cell voltage of 1.50 V to achieve a current density of 20 mA cm−2.

Design and synthesis of integrally structured Ni3N nanosheets/carbon microfibers/Ni3N nanosheets for efficient full water splitting catalysis

2017 ◽  
Vol 5 (19) ◽  
pp. 9377-9390 ◽  
Author(s):  
Tingting Liu ◽  
Mian Li ◽  
Chuanlai Jiao ◽  
Mehboob Hassan ◽  
Xiangjie Bo ◽  
...  
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Cell Voltage ◽  
Electrolysis Cell ◽  
Design And Synthesis ◽  
A Cell ◽  
Carbon Microfibers ◽  
A Current

A (−) Ni3N/CMFs/Ni3N‖Ni3N/CMFs/Ni3N (+) electrolysis cell requires a cell voltage of only 1.65 V to achieve a current density of 20 mA cm−2.

Controllable synthesis of NiO/Ni3S2 hybrid arrays as efficient electrocatalysts for water splitting

2018 ◽  
Vol 42 (22) ◽  
pp. 18201-18207 ◽  
Author(s):  
Xiaoqiang Du ◽  
Qibin Wang ◽  
Xiaoshuang Zhang
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Cell Voltage ◽  
Controllable Synthesis ◽  
A Cell ◽  
A Current

NiO/Ni3S2 affords a current density of 10 mA cm−2 in 1.0 M KOH at a cell voltage of 1.59 V, i.e., comparable to the commercial 20 wt% IrO2/C–40 wt% Pt/C couple (1.55 V at 10 mA cm−2).

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