scholarly journals Energy-Density Improvement in Li-Ion Rechargeable Batteries Based on LiCoO2 + LiV3O8 and Graphite + Li-Metal Hybrid Electrodes

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2025
Author(s):  
Ki Yoon Bae ◽  
Sung Ho Cho ◽  
Byung Hyuk Kim ◽  
Byung Dae Son ◽  
Woo Young Yoon
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Discharge Capacity ◽  
Electrochemical Impedance ◽  
Rechargeable Batteries ◽  
Battery System ◽  
X Ray ◽  
Metal Anode ◽  
Synthesis Conditions ◽  
A Cell

We developed a novel battery system consisting of a hybrid (LiCoO2 + LiV3O8) cathode in a cell with a hybrid (graphite + Li-metal) anode and compared it with currently used systems. The hybrid cathode was synthesized using various ratios of LiCoO2:LiV3O8, where the 80:20 wt% ratio yielded the best electrochemical performance. The graphite and Li-metal hybrid anode, the composition of which was calculated based on the amount of non-lithiated cathode material (LiV3O8), was used to synthesize a full cell. With the addition of LiV3O8, the discharge capacity of the LiCoO2 + LiV3O8 hybrid cathode increased from 142.03 to 182.88 mA h g−1 (a 28.76% improvement). The energy density of this cathode also increased significantly, from 545.96 to 629.24 W h kg−1 (a 15.21% improvement). The LiCoO2 + LiV3O8 hybrid cathode was characterized through X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Its electrochemical performance was analyzed using a battery-testing system and electrochemical impedance spectroscopy. We expect that optimized synthesis conditions will enable the development of a novel battery system with an increase in energy density and discharge capacity.

Enhanced Electrochemical Performance of CoB Amorphous Alloy through the Addition of Lanthanum

2018 ◽  
Vol 914 ◽  
pp. 102-108
Author(s):  
Wei Zhao ◽  
Yi Lin Liao ◽  
Shu Jun Qiu ◽  
Hai Liang Chu ◽  
Yong Jin Zou ◽  
...  
Keyword(s):  
Amorphous Alloy ◽  
Electrochemical Performance ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Current Density ◽  
Discharge Current ◽  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
High Rate ◽  
Discharge Current Density

In order to investigate the effect of lanthanum on the electrochemical properties of CoB amorphous alloy, Co-Lax-B alloys (x = 0, 0.1, 0.5, and 1) were prepared by chemical reduction method. As negative electrodes in alkaline rechargeable batteries, Co-Lax-B alloys exhibit superior electrochemical properties. For Co-La0.1-B alloy, at the discharge current density of 100 mA/g, the initial discharge capacity is 830.6 mAh/g and the discharge capacity has remained around 317.3 mAh/g even after 100 cycles. Moreover, the high-rate discharge ability (HRD) of Co-La0.1-B alloy electrode at the discharge current density of 300 mA/g, 600 mA/g, and 900 mA/g is 98.16%, 95.17%, and 91.86%, respectively. The anodic polarization (AP) and the electrochemical impedance spectra (EIS) measurements indicate that the kinetics of electrochemical performance of the alloys is remarkably improved with the addition of lanthanum.

Electrochemical Performance Cr Doped Spinel LiMn2O4 Cathode for Lithium Ion Batteries

2014 ◽  
Vol 636 ◽  
pp. 49-53
Author(s):  
Si Qi Wen ◽  
Liang Chao Gao ◽  
Jia Li Wang ◽  
Lei Zhang ◽  
Zhi Cheng Yang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Cycle Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Discharge Test

To improve the cycle performance of spinel LiMn2O4as the cathode of 4 V class lithium ion batteries, spinel were successfully prepared using the sol-gel method. The dependence of the physicochemical properties of the spinel LiCrxMn2-xO4(x=0,0.05,0.1,0.2,0.3,0.4) powders powder has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge test and electrochemical impedance spectroscopy (EIS). The results show that as Mn is replaced by Cr, the initial capacity decreases, but the cycling performance improves due to stabilization of spinel structure. Of all, the LiCr0.2Mn1.8O4has best electrochemical performance, 107.6 mAhg-1discharge capacity, 96.1% of the retention after 50 cycles.

Synthesis and Characterization of Li0.97K0.03FePO4/Graphene Composites by Carbonthermal Reduction Method

2014 ◽  
Vol 687-691 ◽  
pp. 4327-4330
Author(s):  
Yan Wang ◽  
Zhe Sheng Feng ◽  
Lu Lin Wang ◽  
Jin Ju Chen ◽  
Zhen Yu He
Keyword(s):  
Discharge Capacity ◽  
Photoelectron Spectroscopy ◽  
Reduction Method ◽  
Electrochemical Impedance ◽  
Impedance Spectra ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Electrochemical Impedance Spectra ◽  
X Ray

Li0.97K0.03FePO4 and Li0.97K0.03FePO4/graphene composites were synthesized by carbothermal reduction method using acetylene black as carbon source. The structure and electrochemical properties of the prepared materials were investigated with X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, galvanostatic charge and discharge and electrochemical impedance spectra tests. The results indicated that K doping improves the cyclic stability of samples, the addition of small amounts of graphene results in better electronic properties on sample. Li0.97K0.03FePO4/graphene showed discharge capacity of 158.06 and 90.55 mAh g-1 at 0.1 C and 10 C, respectively. After the 50 cycle test at different rates, the reversible discharge capacity at 0.1 C was 158.58 mAh g-1, indicating the capacity retention ratio of 100.32%.

Preparation of Co-B Alloy with the Assistance of the Sonication and its Electrochemical Properties

2017 ◽  
Vol 727 ◽  
pp. 751-755 ◽  
Author(s):  
Wei Zhao ◽  
Yi Lin Liao ◽  
Jian Ling Huang ◽  
Hai Liang Chu ◽  
Shu Jun Qiu ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
Negative Electrode ◽  
Rechargeable Batteries ◽  
X Ray Diffraction ◽  
Discharge Current Density ◽  
Negative Electrode Materials

In order to enhance the electrochemical properties of Co-B alloys used as negative electrode materials of alkaline rechargeable batteries, Co-B alloy was successfully prepared by a chemical reduction method with the assistance of the sonication. The phase structure and the surface morphology of the as-prepared Co-B alloys were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen physisorption. Moreover, the electrochemical performance was characterized by galvonostatic charge-discharge tests, electrochemical impedance spectroscopy (EIS) and anodic polarization (AP). Co-B alloy prepared with the assistance of the sonication consists of small particles with a uniform distribution. The electrochemical measurements showed that at a discharge current density of 100 mA/g, the initial discharge capacity was 858.1 mAh/g and the discharge capacity was 322.6 mA/g even at the 100th cycle with the capacity retention of 37.6%.

scholarly journals Influence of Ti Substitution on Electrochemical Performance and Evolution of LiMn1.5−x Ni0.5TixO4 (x = 0.05, 0.1, 0.3) as a High Voltage Cathode Material with a Very Long Cycle Life

Inorganics ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Svetlana Niketic ◽  
Chae-Ho Yim ◽  
Jigang Zhou ◽  
Jian Wang ◽  
Yaser Abu-Lebdeh
Keyword(s):  
Energy Density ◽  
High Voltage ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
High Energy ◽  
High Energy Density ◽  
Partial Substitution ◽  
High Temperature Stability ◽  
X Ray

The high voltage spinel material LiMn1.5Ni0.5O4 (LMNO) has the potential to increase the energy density of lithium batteries. However, its battery performance suffers from poor long-term cycling and high-temperature stability. In order to overcome these limitations, we have studied the effect of partial substitution of Mn with Ti and LiMn1.5−x Ni0.5TixO4 (x = 0.05, 0.1, 0.3), LMNTO, materials have been synthesized in a newly modified sol-gel method and then characterized by TEM, SEM (EDX), AC Electrochemical Impedance Spectroscopy and Soft X-ray Spectromicroscopy. We have demonstrated that the long-term cycling limitation with these types of materials can be resolved and herein 2000 cycles at a high C-rate have been demonstrated in half cells. We have attributed this behavior to a possible charge compensation mechanism as evidenced by a Soft X-ray Spectromicroscopy study of delithiated LMNTO materials. This work takes high energy density batteries based on high voltage spinel material one step further towards commercialization, and it is believed that further improvement can be achieved using new electrolyte formulations.

ELECTRODEPOSITION OF POLYPYRROLE/MnO2 NANOCOMPOSITE ON GRAPHITE FELT AS FREE-STANDING ELECTRODE FOR SUPERCAPACITORS

NANO ◽  
2013 ◽  
Vol 08 (02) ◽  
pp. 1350020 ◽  
Author(s):  
MINGPING HE ◽  
YUYING ZHENG ◽  
QIFENG DU
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Electrochemical Impedance ◽  
Easy Access ◽  
Cyclic Voltammogram ◽  
Free Standing ◽  
X Ray ◽  
Graphite Felt

Polypyrrole/manganese dioxide nanocomposite was deposited on graphite felt (GF) via electrodeposition to fabricate polypyrrole/manganese dioxide/graphite felt (PYMG), which can be used as novel free-standing electrode for supercapacitors. The microstructure and morphology of the as-prepared samples were characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cyclic voltammogram (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) techniques were employed to investigate the electrochemical performance of the composites. The PYMG electrode displayed specific capacitance as high as 596.3 Fg-1 at the current density of 0.5 Ag-1, which is much higher than that of polypyrrole/manganese dioxide (PPy/ MnO2 ) composite reported previously. The high specific capacitance of PYMG may be attributed to the fact that the porous GF is a good conductive matrix for the dispersion of PPy/ MnO2 composite and it can facilitate easy access of electrolytes to the electrode, which results in enhancement of the electrochemical performance of the composite. Furthermore, the PYMG composite exhibited enhanced specific capacitance compared to MnO2 /GF (MGF) and PPy/GF, which may be ascribed to the synergistic effect of PPy and MnO2 .

scholarly journals Continuous Composition Spread and Electrochemical Studies of Low Cobalt Content Li(Ni,Mn,Co)O2 Cathode Materials

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 366 ◽  
Author(s):  
JongSeok Jung ◽  
Haena Yim ◽  
Narendra Singh Parmar ◽  
Jae-Seung Lee ◽  
Ji-Won Choi
Keyword(s):  
Thin Film ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Electrochemical Impedance ◽  
Cobalt Content ◽  
Electrochemical Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
X Ray Absorption

Many scientific efforts have been undertaken toward reducing the Co content in LiMn1/3Ni1/3Co1/3O2 cathode materials for thin-film batteries. In this study, we present cathodes with a wide range of Li(Ni, Mn, Co)O2 compositions to determine the material with the best electrochemical performance by changing the ratio of Ni to Mn at a fixed 0.1 at.% of Co by the continuous composition spread sputtering method. The cathode composition measurements by Rutherford backscattering spectroscopy show that the best electrochemical performance is obtained for a composition of Ni:Mn:Co = 19:71:10. The reasons for this improved electrochemical performance are further investigated by X-ray diffraction, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, and X-ray absorption near edge spectroscopy.

scholarly journals Preparation and Study of Waterborne Asphalt Pavement Maintenance Agent

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Yuan Chunfei
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion ◽  
Retention Rates ◽  
Constant Current ◽  
Capacity Retention ◽  
X Ray ◽  
Synthesis Conditions ◽  
Pavement Maintenance ◽  
Effi Ciency ◽  
Constant Current Charge

The precursor Ni0.76Co0.1Mn0.1 (OH) 2 was prepared by coprecipitation method. The precursor was mixed withMg (OH) 2 / Zn (NO3) 2 / TiO2 and LiOH.H2O, Li2CO3 to synthesize doped lithium Ion layer positive electrodematerial Li [Ni0.8-xCo0.1Mn0.1Mx] O2 (x = 0.04). The effects of synthesis conditions on the chemical propertiesof the composites were discussed. The synthesized samples were prepared by scanning electron microscopy (SEM),thermogravimetry - diff erential thermal analysis (TG / DTA), X - ray diff raction (XRD) and constant current charge- Testing and characterization. The results show that the crystallinity of Li [Ni0.8-xCo0.1Mn0.1Mx] O2 (x = 0.04)prepared at 900 ℃ for 20 h is good, and it has good layered structure. The properties of the doped elements The resultsshow that the electrochemical performance of the samples with Mg and Zn is good, and the fi rst discharge capacity is0.1.5mA.h / g and 144.2 mA.h / g (2.8 ~ 4.6 V vs Li + / Li ), The fi rst charge and discharge effi ciency was 51.8% and58.1% respectively, and the capacity retention rates after 8 and 10 cycles were 92.4% and 78.5% respectively. The fi rstdischarge capacity of the Ti doped sample was 51.3 mA.h / G, poor electrochemical performance.

Carbon Nanotubes/MnO2 Composite Fabricated via Laser Welding and Electrodeposition as Flexible Electrode for Supercapacitors

NANO ◽  
2019 ◽  
Vol 14 (06) ◽  
pp. 1950074 ◽  
Author(s):  
Mingping He ◽  
Jianguang Li ◽  
Wanli Xu ◽  
Zhenqiang Dong ◽  
Yuechao Wu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Performance ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Easy Access ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
Porous Network ◽  
Flexible Electrode ◽  
X Ray

Carbon nanotubes (CNTs) were welded on the surface of thermoplastic polypropylene (PP) substrate by laser irradiation and then manganese dioxide (MnO2) was deposited on the surface of CNTs by electrochemical method to prepare CNTs/MnO2 flexible electrodes (L-CM). The microstructure and morphology of CNTs/MnO2 composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results showed that CNTs were welded on the surface of the substrate, adhering to each other to form a porous network structure. In addition, there were distinct small protrusions on the surface of CNTs, indicating that MnO2 had been successfully deposited on the surface of CNTs. Cyclic voltammogram (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques were employed to investigate the electrochemical performance of the composites. Compared with CNTs/MnO2 composite prepared via compaction (denoted as C-CM), L-CM composite prepared under the laser power of 0.75[Formula: see text]W (denoted as L-CM75) showed a larger capacitance of 214.6[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] and displayed excellent bendability, demonstrating capacitance retention of approximately 89.6% after 1000 bending cycles. The excellent performance of L-CM75 may be attributed to the fact that the CNTs welded on the substrate have formed an effective conductive network whose porous structure can facilitate easy access of electrolytes to the electrode, which results in enhancement of the electrochemical performance of L-CM75.

Preparation and Capacitance Properties of Nickel-Cobalt Sulfide/Graphene Composites

2019 ◽  
Vol 956 ◽  
pp. 35-45
Author(s):  
Shi Huai Zhao ◽  
Wen Wen Xu ◽  
Xiao Ming Zhao ◽  
Zi Bo Yang
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Shell Structure ◽  
Electrochemical Impedance ◽  
High Energy ◽  
High Energy Density ◽  
Cobalt Sulfide ◽  
Core Shell ◽  
Nickel Cobalt ◽  
Core Shell Structure

In order to explore the supercapacitor electrode material with high energy density, a composite material that nickel-cobalt sulfide loaded in graphene (NiCo2S4@rGO) with core-shell structure was successfully prepared by hydrothermal, room temperature vulcanization and annealing. The core-shell structure of the material greatly increased the contact area between the material and the electrolyte and improved the electrochemical performance. In addition, the energy density has been significantly improved. NiCo2S4@rGO was characterized by field emission scanning electron microscopy (SEM), high-resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectrometer. The electrochemical properties of the material were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the capacitance can reach 1100 F/g at the current density of 0.5 A/g. Furthermore, the NiCo2S4@rGO as positive electrode and reduced graphene oxide (rGO) as negative electrode were assembled into an asymmetric supercapacitor (ASC). The device exhibits a high energy density of 74.78 Wh/Kg at a power density of 400 W/Kg, as well as excellent cycling stability of 88.9% after 3 000 cycles, which reflects the excellent electrochemical performance of the material.

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