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).

LiMn2O4 Prepared by Liquid Phase Flameless Combustion with F-Doped for Lithium-Ion Battery Cathode Materials

2013 ◽  
Vol 652-654 ◽  
pp. 825-830 ◽  
Author(s):  
Ming Wu Xiang ◽  
Xian Yan Zhou ◽  
Zhi Fang Zhang ◽  
Mi Mi Chen ◽  
Hong Li Bai ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Electrochemical Performance ◽  
Raw Materials ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Flameless Combustion ◽  
Capacity Retention ◽  
Vibrational Bands ◽  
Novel Method ◽  
Discharge Capacities

LiMn2O4-yFywere synthesized by a novel method named liquid phase flameless combustion reaction with LiNO3, MnAc2.4H2O and LiF as raw materials calcined at 600 °C for 3 h with HNO3as aided oxidant. All samples were investigated by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and electrochemical performance. The results show that: all samples have main phase of LiMn2O4with impurity of Mn3O4and the vibrational bands of Mn-O are a little red shift by doping F, which indicated that the F- enter the host structure of LiMn2O4successfully. The electrochemical performance show that the initial discharge capacities of F-doped samples are lower than pristine LiMn2O4, which is 117.7 mAh•g-1. However, the capacity retention of LiMn2O3.96F0.04and LiMn2O3.90F0.10are 73.6% and 74.5%, respectively, which are higher than pristine LiMn2O4, which is only 69.0% after 40 cycles.

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.

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.

Synthesis and Electrochemical Properties of CuC2O4·xH2O and CuC2O4·xH2O/Carbon Nanotubes (CNTs) Anodes for Lithium-Ion Batteries

2020 ◽  
Vol 20 (3) ◽  
pp. 1740-1748
Author(s):  
Yi-Ni Hu ◽  
Zi-Han Lin ◽  
Fei-Xia Min ◽  
Fei Teng ◽  
Hui-Min Wu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Lithium Ion Batteries ◽  
Anode Materials ◽  
Hydrothermal Process ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Promising Candidate ◽  
X Ray ◽  
Discharge Capacities ◽  
A Current

Pure CuC2O4·xH2O and CuC2O4·xH2O/carbon nanotubes (CNTs) composites are synthesized by a low-temperature hydrothermal process. The structure and morphology of the products are analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG) and Raman spectrum. The results demonstrate that the as-prepared CuC2O4·xH2O takes on a microsphere-like morphology, all CuC2O4·xH2O/CNTs nanocomposites are constructed by the intertwining of tabular CuC2O4·xH2O nanoparticles (NPs) and CNTs to form a tanglesome net. When evaluated as an anode materials for lithium ion batteries (LIBs), all CuC2O4·xH2O/CNTs electrodes possess higher reversible discharge capacities (more than 1000 mAh g-1) than the pure CuC2O4·xH2O, up to 200th cycle at a current density of 100 mA g-1. The results illustrate that the addition of CNTs can enhance the electrochemical performance of CuC2O4·xH2O. Overall, CuC2O4·xH2O/CNTs composite can be a promising candidate used as a promising anode for LIBs.

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.

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.

Electrochemical lithiation-induced polymorphism of anthraquinone derivatives observed by operando X-ray diffraction

2015 ◽  
Vol 17 (41) ◽  
pp. 27665-27671 ◽  
Author(s):  
Katharine E. Silberstein ◽  
James P. Pastore ◽  
Weidong Zhou ◽  
Rebecca A. Potash ◽  
Kenneth Hernández-Burgos ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Molecular Crystals ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Molecular Crystals ◽  
Coin Cell ◽  
Electrochemical Lithiation ◽  
Anthraquinone Derivatives ◽  
Diffraction Patterns

Operando X-ray diffraction patterns of organic molecular crystals in lithium-ion batteries provide evidence for polymorphism via a modified coin cell.

Study of LiNi0.6Co0.2Mn0.2O2 Coated with Li2ZrO3 Nanolayers in All-Solid-State Lithium Ion Batteries

2020 ◽  
Vol 12 (3) ◽  
pp. 412-421 ◽  
Author(s):  
Young-Jin Kim ◽  
Rajagopal Rajesh ◽  
Kwang-Sun Ryu
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Interfacial Resistance ◽  
Capacity Retention ◽  
Coating Agent ◽  
X Ray

The Li2ZrO3 nanolayer was coated over LiNi0.6Co0.2Mn0.2O2 cathode material (NCM) to produce all-solid-state lithium ion batteries and their enhanced electrochemical properties were determined. To relieve interfacial resistance resulting from insufficient contact, a Li2ZrO3 nanolayer is a suitable cathode coating agent because it can block corrosive species and decrease contact loss, along with elimination of the space-charge layer. All-solid-state cells using Li2ZrO3-coated NCM material showed higher capacity than pristine NCM. X-ray diffraction patterns showed the same peak separations and lattice parameters as pristine material. Scanning electron microscopy and transmission electron microscopy images obtained with electron dispersive spectroscopy mapping confirmed homogeneous coating with a uniformly thick Li2ZrO3 layer of around 5 nm. X-ray photoelectron spectroscopy revealed that the surface of NCM had two different O1s peaks, with a Zr–O peak, and Ni, Co, Mn, and Zr peaks. Electrochemical studies on pristine and Li2ZrO3-coated NCM materials were conducted using electrochemical impedance spectroscopy with galvanostatic cycle performances by constructing an all-solid-state cell. The impedance spectra showed relieved interfacial resistance with low polarization as coating agent was added. Notably, the 4 wt.% Li2ZrO3-coated NCM exhibited capacity retention of 81% at a current density of 0.12 mA/cm2 after 30 cycles, while that of the pristine cell hadunstable cycle performance and a low capacity retention of 69 percent. Thus, the Li2ZrO3-coated NCM material exhibited potential for all-solid-state batteries requiring high power or stable application.

Preparation of LiCoO2 from Cathode Materials of Spent Lithium Ion Batteries

2011 ◽  
Vol 183-185 ◽  
pp. 1553-1557 ◽  
Author(s):  
Fang Gu ◽  
Qian Nie
Keyword(s):  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
Retention Rate ◽  
Ammonium Oxalate ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Excellent Electrochemical Performance ◽  
Pure Phase

Preparation of LiCoO2 cathode materials from spent lithium ion batteries are presented. The processes contain reduction, separation, precipitation, regeneration. The optimum conditions of recovery are: the calcination temperature is 500°C, the volume rate of sulfuric acid and the water reaches 0.375, the hightest leach-ing rate of cobalt is 43.53%. According to the solubility of oxalate, ammonium oxalate is choiced as precipitation agent. The investigation of X-ray diffraction (XRD), scanning electron microscopy (SEM), charge-discharge testes at voltage ranges rate from 2.8V to 4.2V versus Li , 0.2 C rate are performed. The results reveal that the regenerative LiCoO2 is pure phase, initial discharge capacity is 128.63 mAh•g-1, after 50 cycles the discharge capacity is 118.61 mAh•g-1, capacity retention rate is 92.21%. The regenerative LiCoO2 exhibits excellent electrochemical performance and stability. The materials may find promising applications in lithium ion batteries.

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