Preparation of Spherical FePO4 Cathode Material for Lithium Ion Batteries

2011 ◽  
Vol 347-353 ◽  
pp. 576-581 ◽  
Author(s):  
Xi Yang ◽  
Jun Xi Zhang ◽  
Shi Ming Zhang ◽  
Li Cheng Yan ◽  
Ying Mei ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Lithium Ion ◽  
Spherical Particles ◽  
Precipitation Process ◽  
Drying Method ◽  
X Ray Diffraction ◽  
Co Precipitation ◽  
The Ideal

The spherical FePO4 was prepared by a novel co-precipitation process followed by spray drying method, using Fe (NO3)3•9H2O, NH4H2PO4, NH3•H2O and polyvinyl alcohol. The pH value plays a pivotal role in determining the morphology of spherical particles; the sample, obtained at pH=3, was found to have the ideal spherical particles and electrochemical property. The X-ray diffraction analysis showed the phase transition of FePO4 with calcining temperature, amorphous FePO4 can exhibit better performance than the crystalline phase. Electrochemical behavior of spherical FePO4 was studied by the charge-discharge tests and electrochemical impedance spectroscopy. The results show that this process is a promising method to prepare spherical FePO4cathode materials for lithium ion batteries.

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).

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.

scholarly journals A Study to Explore the Suitability of LiNi0.8Co0.15Al0.05O2/Silicon@Graphite Cells for High-Power Lithium-Ion Batteries

2021 ◽  
Vol 22 (19) ◽  
pp. 10331
Author(s):  
Marta Cabello ◽  
Emanuele Gucciardi ◽  
Guillermo Liendo ◽  
Leire Caizán-Juananera ◽  
Daniel Carriazo ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
Irreversible Damage ◽  
Main Challenge ◽  
Silicon Based

Silicon–graphite (Si@G) anodes are receiving increasing attention because the incorporation of Si enables lithium-ion batteries to reach higher energy density. However, Si suffers from structure rupture due to huge volume changes (ca. 300%). The main challenge for silicon-based anodes is improving their long-term cyclabilities and enabling their charge at fast rates. In this work, we investigate the performance of Si@G composite anode, containing 30 wt.% Si, coupled with a LiNi0.8Co0.15Al0.05O2 (NCA) cathode in a pouch cell configuration. To the best of our knowledge, this is the first report on an NCA/Si@G pouch cell cycled at the 5C rate that delivers specific capacity values of 87 mAh g−1. Several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and gas chromatography–mass spectrometry (GC–MS) are used to elucidate whether the electrodes and electrolyte suffer irreversible damage when a high C-rate cycling regime is applied, revealing that, in this case, electrode and electrolyte degradation is negligible.

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.

scholarly journals SYNTHESIS OF SPINEL Mn3O4 AND SPINEL Mn3O4/ZrO2 NANOCOMPOSITES AND USING THEM IN PHOTO-CATALYTIC DECOLORIZATION OF Fe(II)-( 4,5- DIAZAFLUOREN-9-ONE 11) COMPLEX

2020 ◽  
Vol 17 (34) ◽  
pp. 689-699
Author(s):  
Mohammed Kareem HAYAWI ◽  
Mohanad Mousa KAREEM ◽  
Luma Majeed AHMED
Keyword(s):  
Model Material ◽  
Spherical Particles ◽  
Ratio Method ◽  
Nano Composites ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mole Ratio Method ◽  
Co Precipitation

The spinel structure Mn3O4 and the spinel Mn3O4/ZrO2 nano-composites particles were synthesized successfully as photocatalysts by employing the co-precipitation process and ultrasonic technique, respectively. The morphology of the top mention prepared photocatalysts was distinguished using X-ray diffraction (XRD) technology and atomic force microscopy (AFM) and indicated that the mean crystal sizes and particle sizes for all studied samples were nanometric. In addition, the optical properties of the obtained photocatalysts were investigated using a UV-Visible spectrophotometer with Labsphere diffuse reflectance accessory to measure the bandgaps of them. Based on the Tauc equation, the bandgaps (Bg) for the studied photocatalysts were determined. The bandgaps are indirect for all samples, and it is increased in values for the nanocomposites with the increasing the ratio of ZrO2. So, the sequence of bandgaps values is: Bg spinel Mn3O4 Bg Comp.1 Bg Comp.2 Bg Comp.3 Bg ZrO2, and equal to 2.21 eV 3.15 eV 4.51 eV 4.26 eV 5.29 eV. The research revealed that the spinel Mn3O4 and the spinel Mn3O4 ZrO2 nano-composites particles were quasispherical and spherical particles respectively. Moreover, the incorporation of spinel Mn3O4 particle with ZrO2 particle was successfully carried out that was proved by XRD and AFM analyses. This work discovered that the photocatalytic reaction response via employing Fe(II)-(4,5-Diazafluoren-9-one 11) complex as model material under UV-A lamp with the use of the studied photocatalysts. The primary photo experiments for these photocatalysts found that the decolorization of Fe(II)-(4,5-Diazafluoren-9-one 11) complex is not active without addition of H2O2, that attitude is due to the very high stability of these complex with having an octahedral structure, which was proved with using mole ratio method. Whereas, after the addition of H2O2 to the aqueous solution of these complex, the activity with using the spinel Mn3O4 ZrO2 nanocomposite 3 was found to be the double active than that using the spinel Mn3O4 alone, and the sequence of phootdecolorization efficiency (E%) is being: E% composite 3 E% composite 2 E% composite 1 E% spinel Mn3O4.

scholarly journals Enhanced electrochemical performance of RuO2 doped LiNi1/3Mn1/3Co1/3O2 cathode material for Lithium-ion battery

2021 ◽  
Author(s):  
K. Kalaiselvi ◽  
S. Premlatha ◽  
M. Raju ◽  
Paruthimal Kalaignan Guruvaiah
Keyword(s):  
Electrochemical Performance ◽  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
High Discharge Capacity ◽  
Nitrate Precursor

Abstract LiNi1/3Mn1/3Co1/3O2 as a promising cathode material for lithium-ion batteries was synthesized by a sol-gel method using nitrate precursor calcined at 800°C for 10 hours. The crystallite nature of samples is confirmed from X-ray diffraction analysis. SEM and TEM analyses were used to investigate the surface morphology of the prepared samples. It was found that, highly crystalline polyhedral RuO2 nanoparticles are well doped on the surface of pristine LiNi1/3Mn1/3Co1/3O2 with a size of about approximately 200 nm. The chemical composition of the prepared samples was characterized by EDX and XPS analyses. The electrochemical performance of the proposed material was studied by cyclic voltammetry and charge/discharge analyses. The electrode kinetics of the samples was studied by electrochemical impedance spectroscopy. The developed RuO2 doping may provide an effective strategy to design and synthesize the advanced electrode materials for lithium ion batteries. The doping strategy has dramatically increased the capacity retention from 74 % to 90% with a high discharge capacity of 251.2 mAhg− 1. 3 % RuO2-doped LiNi1/3Mn1/3Co1/3O2 cathode materials have showed the similar characteristics of two potential plateaus obtained at 2.8 and 4.2 V compared with un doped electrode cathode material. These results revealed the enhanced performance of RuO2- doped LiNi1/3Mn1/3Co1/3O2 during insertion and extraction of lithium ions compared to pristine material.

scholarly journals Enhanced Electrochemical Performance of LiFePO4 Originating from the Synergistic Effect of ZnO and C Co-Modification

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 12
Author(s):  
Xiaohua Chen ◽  
Yong Li ◽  
Juan Wang
Keyword(s):  
Zinc Oxide ◽  
Charge Transfer ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Electron Conductivity ◽  
Spherical Particles ◽  
Commercial Application ◽  
Transfer Resistance

Olivine-structure LiFePO4 is considered as promising cathode materials for lithium-ion batteries. However, the material always sustains poor electron conductivity, severely hindering its further commercial application. In this work, zinc oxide and carbon co-modified LiFePO4 nanomaterials (LFP/C-ZnO) were prepared by an inorganic-based hydrothermal route, which vastly boosts its performance. The sample of LFP/C-xZnO (x = 3 wt%) exhibited well-dispersed spherical particles and remarkable cycling stability (initial discharge capacities of 138.7 mAh/g at 0.1 C, maintained 94.8% of the initial capacity after 50 cycles at 0.1 C). In addition, the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) disclose the reduced charge transfer resistance from 296 to 102 Ω. These suggest that zinc oxide and carbon modification could effectively minimize charge transfer resistance, improve contact area, and buffer the diffusion barrier, including electron conductivity and the electrochemical property. Our study provides a simple and efficient strategy to design and optimize promising olivine-structural cathodes for lithium-ion batteries.

Hydrothermal Synthesis and Electrochemical Performance of LiFePO4/Graphene Composites for Lithium-Ion Batteries

2014 ◽  
Vol 900 ◽  
pp. 242-246 ◽  
Author(s):  
Xing Ling Lei ◽  
Hai Yan Zhang ◽  
Yi Ming Chen ◽  
Wen Guang Wang ◽  
Zi Dong Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Charge Discharge ◽  
Scanning Electron ◽  
Discharge Test

LiFePO4/graphene composites were prepared via a simple hydrothermal method. The as-prepared LiFePO4/graphene composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge-discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests. The lithium-ion batteries using LiFePO4/graphene composites as cathode material exhibited a discharge capacity of 165 mAh/g, which was 97% of the theoretical capacity of 170 mAh/g.

scholarly journals Spherical Li4Ti5O12/NiO Composite With Enhanced Capacity and Rate Performance as Anode Material for Lithium-Ion Batteries

2020 ◽  
Vol 8 ◽  
Author(s):  
Jiequn Liu ◽  
Shengkui Zhong ◽  
Qingrong Chen ◽  
Luchao Meng ◽  
Qianyi Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lithium Ion Batteries ◽  
Anode Material ◽  
Discharge Capacity ◽  
Lithium Ion ◽  
Drying Method ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
X Ray ◽  
Transmission Electron

Compositing with metal oxides is proved to be an efficient strategy to improve electrochemical performance of anode material Li4Ti5O12 for lithium-ion batteries. Herein, spherical Li4Ti5O12/NiO composite powders have been successfully prepared via a spray drying method. X-ray diffraction and high-resolution transmission electron microscopy results demonstrate that crystal structure of the powders is spinel. Scanning electron microscopy results show that NiO uniformly distributes throughout Li4Ti5O12 matrix. It is found that compositing with NiO increases both discharge platform capacity and rate stability of Li4Ti5O12. The as-prepared Li4Ti5O12/NiO (5%) exhibits a high initial discharge capacity of 381.3 mAh g−1 at 0.1 C, and a discharge capacity of 194.7 mAh g−1 at an ultrahigh rate of 20 C.

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