Al(NO3)3 Induced Morphological Changes in Nickel and Cobalt Salts as Advanced Electrodes for Supercapacitors

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
Yong Zhang ◽  
Jing Yang ◽  
Han-xin Mei ◽  
Hai-li Gao ◽  
Xiao-dong Jia ◽  
...  
Keyword(s):  
Electrode Material ◽  
Electrochemical Impedance ◽  
Morphological Changes ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Capacitive Properties ◽  
Current Densities ◽  
Constant Current Charge ◽  
Discharge Capacities

Abstract As one of the important components of the supercapacitor, electrode material has a significant influence on the electrochemical performance of the device. In this study, Ni2(NO3)2(OH)2 · 2H2O/(Co(NH3)5(N3))(N3)2 (NC) composite material was prepared by the microwave-assisted method. The effects of Al(NO3)3 contents on the morphology and structure of the composites were studied by scanning electron microscopy, X-ray diffraction, Raman spectrum, and laser particle size distribution analyzer. The capacitive properties of the composite were analyzed by cyclic voltammetry, constant current charge and discharge, and electrochemical impedance spectroscopy measurements. The results show that the Al(NO3)3 has a significant effect on the morphology and capacitance of NC. When the contents of Al(NO3)3 are 0, 5, 10, 15, and 20 wt%, the discharge capacities of NC, NCA-5, NCA-10, NCA-15, and NCA-20 samples obtained under 1 A/g current density are 1674, 1759, 2645, 1098, and 1321 F/g, respectively. At higher current densities of 4, 7, and 10 A/g, the discharge specific capacities reached 1350, 1064, and 894 F/g, indicating that the NCA-10 composite is a promising electrode material for supercapacitors.

A Facile Synthesis of NiFe2O4 with High Specific Capacitance as Supercapacitor Electrode Material

2018 ◽  
Vol 281 ◽  
pp. 854-858
Author(s):  
Xi Cheng Gao ◽  
Jian Qiang Bi ◽  
Wei Li Wang ◽  
Guo Xun Sun ◽  
Xu Xia Hao ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Capacitance ◽  
Electrochemical Property ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Constant Current Charge ◽  
Supercapacitor Electrode Materials

NiFe2O4 powders were synthesized by a facile hydrothermal method at 180°C followed by a thermal treatment at 300°C. The phase composition and morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed that the NiFe2O4 powders were well-crystallized, and they possessed a particle size in the range of 50-100 nm. The electrochemical property was characterized via cyclic voltammetry (CV) and constant current charge-discharge method. Encouragingly, the NiFe2O4 powders had an excellent electrochemical property, whose specific capacitance reached 266.84 F/g at the electric current density of 1 A/g due to the small particle size. Compared with other Fe-based metal compound oxides, NiFe2O4 has a better electrochemical performance, which can be widely used in the supercapacitor electrode materials.

Preparation of NiO Microspheres by Hydrothermal Method and its Electrochemical Capacitive Properties

2015 ◽  
Vol 814 ◽  
pp. 81-85 ◽  
Author(s):  
Qian Qian Li ◽  
Run Hua Fan ◽  
Ke Lan Yan ◽  
Kai Sun ◽  
Xu Ai Wang ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Rate Capability ◽  
Average Diameter ◽  
Three Dimensions ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
High Specific Capacity ◽  
Capacitive Properties

The precursor Ni (OH)2 was synthesized by a simple hydrothermal method with hexamethylenetetramine ((CH2)6N4) as precipitant and template, and then NiO was gained after calcination. The phase and morphology of the synthesized product were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical capacitive characterization was performed using cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS) in a 6mol/L KOH aqueous solution electrolyte. The result shows that spherical NiO without impurity was synthesized, the average diameter of the spheres is 5 um and these spheres were constructed by the interactive arrangement of many nanoflakes in three dimensions. This kind of NiO shows the typical electrochemical characteristics of pseudo capacitance with high specific capacity and excellent rate capability. The specific capacity can reach 515F/g at the current density of 1A/g

Synthesis and Electrochemical Properties of a LiNi0.7Co0.3O1.9Cl0.1 Cathode Material for Lithium-Ion Battery

2007 ◽  
Vol 336-338 ◽  
pp. 463-465 ◽  
Author(s):  
Xin Lu Li ◽  
Fei Yu Kang ◽  
Yong Ping Zheng ◽  
Xiu Juan Shi ◽  
Wan Ci Shen
Keyword(s):  
Hexagonal Lattice ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Constant Current ◽  
Cyclic Voltammograms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Constant Current Charge ◽  
Initial Cycle ◽  
Partial Oxygen

Partial oxygen in LiNi0.7Co0.3O2 was replaced by chlorine to form LiNi0.7Co0.3O1.9Cl0.1. Phase structure of LiNi0.7Co0.3O1.9Cl0.1 was identified as a pure hexagonal lattice of α-NaFeO2 type by X-ray diffraction. Discharge capacity of LiNi0.7Co0.3O1.9Cl0.1 was 202 mAh/g in initial cycle at 15 mA/g current density in 2.5- 4.3 V potential window. The constant current charge/discharge experiments and cyclic voltammograms showed that chlorine addition was effective to improve reversible capacity and cycle stability of LiNi0.7Co0.3O2.

scholarly journals Electrochemical Behavior of NH4F-Pretreated Li1.25Ni0.20Fe0.13Co0.33Mn0.33O2 Cathodes for Lithium-ion Batteries

2020 ◽  
Vol 10 (3) ◽  
pp. 1021
Author(s):  
Yonglei Zheng ◽  
Yikai Li ◽  
He Wang ◽  
Siheng Chen ◽  
Xiangxin Guo ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Hierarchical Microspheres ◽  
Electrochemical Cycling ◽  
Novel Method ◽  
Diffraction Patterns ◽  
Discharge Capacities

We report a novel method to fabricate lithium-ion batteries cathodes with the NH4F pretreatment. In this study, NH4F-pretreated Li1.25Ni0.20Fe0.13Co0.33Mn0.33O2 hollow nano-micro hierarchical microspheres were synthesized for use as cathode materials. The X-ray diffraction patterns of NH4F-pretreated Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 were analyzed with the RIETAN-FP software program, and the results showed that the samples possess a layered α-NaFeO2 structure. The effects of pretreatment with NH4F on the electrochemical performance of the pristine material were evaluated through charge/discharge cycling, the rate performance, and electrochemical impedance spectroscopy (EIS). Pretreatment with NH4F significantly improved the discharge capacities and coulombic efficiencies of Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 in the first cycle and during subsequent electrochemical cycling. The sample pretreated with an appropriate amount of NH4F (NFCM 90) showed the highest discharge capacity (209.1 mA h g−1) and capacity retention (85.2% for 50 cycles at 0.1 C). The EIS results showed that the resistance of the NFCM 90 sample (76.32 Ω) is lower than that of the pristine one (206.2 Ω).

Cathode Material Li [Li0.2 Mn0.44Ni0.18Co0.18]O2 Synthesized by Molten Salt Method

2013 ◽  
Vol 690-693 ◽  
pp. 981-984
Author(s):  
Guang Xin Fan ◽  
Hui Lian Li ◽  
Shu Pu Dai ◽  
Chuan Xiang Zhang ◽  
Xue Mao Guan ◽  
...  
Keyword(s):  
Molten Salt ◽  
Specific Area ◽  
Constant Current ◽  
Molar Ratio ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Structures And Properties ◽  
Constant Current Charge

In this paper, LiOH·H2O and Li2CO3, which were widely used in industry and (Mn0.533Co0.233Ni0.233) (OH)2prepared by ourselves selected as starting materials, series materials of lithium-rich layered material Li [Li0.2Mn0.44Ni0.18Co0.18]O2were obtained by a molten salt method. Their structures and properties of the materials were investigated by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and constant current charge/discharge methods. The effects of different LiOH and Li2CO3molar ratios on the Li [Li0.2Mn0.44Ni0.18Co0.18]O2structures and properties were characterized. The results of the experiments indicate that The structures of the material such as crystal structure, the specific area, particle size distribution, tap densities were controlled by adjusting the proportion of the two lithium sources. Forthermore , when the molar ratio of LiOH and Li2CO3was 3:7, the maximum discharge capacity (214.77 mAhg-1) of the cathode was obtained.

scholarly journals Substitution of Acetylene Black by Using Modified Flake Graphite Applied in Activated Carbon Supercapacitors

2018 ◽  
Vol 160 ◽  
pp. 03005
Author(s):  
Peng Zhao ◽  
Chunmei He ◽  
Wencheng Hu
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Electrochemical Impedance ◽  
Normal Pressure ◽  
Acetylene Black ◽  
Flake Graphite ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Capacitive Properties ◽  
Methyl Pyrrolidone

Flake graphite was mechanically modified at different times in N-methyl pyrrolidone under normal pressure. The results of the scanning electron microscopy, X-ray diffraction, and transmission electron microscopy suggested that the structure of the flake graphite was modified. The crystallinity of the flake graphite, and many defects were introduced into the material. The evaluation of capacitor performance by cyclic voltammetry, galvanostatic charge/discharge tests, and electrochemical impedance spectroscopy was also performed. Results showed that the electrochemical performance of flake graphite was strongly enhanced, particularly when it was exfoliated for 6 h. Moreover, the electrochemical capacitive properties of activated carbon were obviously enhanced through the substitution of acetylene black by flake graphite modified for 6 h.

Temperature Controlled Synthesis of Ce–MnO2 Nanostructure: Promising Electrode Material for Supercapacitor Applications

2020 ◽  
Vol 12 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Rajesh Rajagopal ◽  
Kwang-Sun Ryu
Keyword(s):  
Electrode Material ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Supercapacitor Application ◽  
Structural Details ◽  
Different Temperatures ◽  
Microscope Technique ◽  
Supercapacitor Applications

The objective of this study was to prepare Ce–MnO2 nanostructure composite as an electrode material for supercapacitor application. Ce–MnO2 nanostructure composite was synthesized by facile hydrothermal method at different temperatures. Structural details of pure and Ce–MnO2 nanostructure composite were studied using powder X-ray diffraction technique. The formation of flower like structure and strong interaction with Ce and MnO2 were confirmed by field emission electron microscope technique. Their electrochemical performances were elucidated by using cyclic voltammetry, charge–discharge, and electrochemical impedance spectroscopy techniques. Nearly rectangular shaped cyclic voltagram was observed for synthesized Ce–MnO2 nanostructure composite electrode, indicating the existence of electric double layer capacitance nature. Ce–MnO2 (130) nanostructure composite exhibited high specific capacitance value of 147.25 F/g at applied current density of 1 A/g in 1 M Li2SO4 aqueous electrolyte. Furthermore, resistive and capacitive behaviors of these electrodes were studied from Nyquist and bode diagrams within frequency range of 10 mHz to 100 kHz.

Preparation of Nickel and Manganese Dioxide by Co-Precipitation and its Electrochemical Capacitive Properties

2015 ◽  
Vol 814 ◽  
pp. 86-90
Author(s):  
Qian Qian Li ◽  
Run Hua Fan ◽  
Yu Jun Bai ◽  
Chuan Bing Cheng ◽  
Gui Fang Liu ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Manganese Oxides ◽  
Electrochemical Impedance ◽  
Spherical Particles ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Capacitive Properties ◽  
Co Precipitation ◽  
Redox Capacitance

The precursor nickel and manganese carbonates were synthesized by co-precipitation with sodium carbonate as precipitant, and then nickel and manganese oxides were gained after calcination. The phase and morphology of the synthesized product were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical characterization was performed using cyclic voltammetry (CV), galvanostatic charge–discharge tests (GCD) and electrochemical impedance spectroscopy (EIS) in a 6mol/L KOH aqueous solution electrolyte. The result showed that the products were the mixture of nickel and manganese oxides and solid solution. nanoparticles and spherical particles were gained by controlling the molar ratio of nickel and manganese. All of the samples exhibited typical Faradic redox capacitance. The specific capacitance was different with the change of nickel and manganese molar ratio. The specific capacitance (Cs) reached 130F/g at 1A/g when the ratio was 2:1.

Surface Modification of Spinel LiMn2O4 with Y2O3 for Lithium-Ion Battery

2011 ◽  
Vol 391-392 ◽  
pp. 1069-1074 ◽  
Author(s):  
Ying Bai ◽  
Feng Wu ◽  
Hua Tong Yang ◽  
Yu Zhong ◽  
Chuan Wu
Keyword(s):  
Surface Modification ◽  
Chemical Process ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Discharge Characteristics ◽  
X Ray ◽  
Passivating Films ◽  
Discharge Capacities ◽  
Charge Discharge

Spinel LiMn2O4was modified with Y2O3coating by a chemical process. The crystal structures of the as-prepared samples were investigated by X-ray diffraction (XRD). The charge/discharge characteristics of the modified samples were evaluated at different rates between 3.0 and 4.4V. The discharge capacities of 2.0 wt.% Y2O3-coated LiMn2O4are 116 mAh•g−1, 99.7mAh•g−1, 93.3mAh•g−1and 82.9mAh•g−1at 0.1C, 0.5C, 1C and 2C rates (at 20◦C). The cycle abilities improvement of the spinel LiMn2O4coated with Y2O3are demonstrated at elevated temperature (55◦C) and high rates (2C). From the analysis of electrochemical impedance spectroscopy (EIS), the improvement of cycle ability may be attributed to the suppression on the formation of the passivating films and the reduction of Mn dissolution, which result from the surface modification with Y2O3.

The Energy Storage Performance of the Graphene Oxide/Polyaniline Composite

2013 ◽  
Vol 448-453 ◽  
pp. 2938-2941
Author(s):  
Ping Ping Qi ◽  
Yan Li Ruan ◽  
Kun Wang ◽  
Zhe Wang
Keyword(s):  
Graphene Oxide ◽  
Electrode Material ◽  
In Situ Polymerization ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Storage Performance ◽  
Electrochemical Testing ◽  
Pani Composite ◽  
Discharge Capacities

Graphene oxide (GO)/polyaniline (PANI) composite are synthesized via in situ polymerization in the presence of grapheme oxide under acid conditions. The GO/PANI was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and electrochemical testing. The cathodes prepared using PANI and GO/PANI delivered initial discharge capacities of 78mAh/g and 104.4mAh/g ,respectively stable reversible capacities of 58.5mAh/g and 103.7mAh/g after 50 chargedischarge cycles. The GO enhances the discharge capacity of the PANI electrode material. GO/PANI is a good candidate as electrode material in lithium ion batteries

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