Effects of Cr Doping on the Structural and Electrochemical Properties of V6O13

2010 ◽  
Vol 34-35 ◽  
pp. 1780-1783 ◽  
Author(s):  
Yuan Chun Liu ◽  
Zheng Guang Zou ◽  
Fei Long
Keyword(s):  
Electrochemical Properties ◽  
Cathode Materials ◽  
Solid Phase ◽  
Lithium Ion ◽  
Chain Structure ◽  
Raw Material ◽  
Phase Method ◽  
Discharge Process ◽  
Solid Phase Method ◽  
Cr Doping

It has been demonstrated that V6O13 is a very attractive cathode materials for rechargeable lithium-ion batteries. Cr3+ was doped to improve its electrochemical property. CrxV6O13(x =0.01~0.05) cathode materials were prepared using NH4VO3 and Cr2O3 as raw material by solid phase method in argon atmosphere. The best electrochemical properties of CrxV6O13 were obtained under the optimum conditions as follows: the argon flow rate is 85mL/min, the heating rate is 5°C /min, the holding time 1h at 180°C, 1h at 300°C and 30 min at 450°C. The structural and electrochemical properties were examined by means of X-ray diffraction, SEM and charge–discharge tests. The results demonstrated that the powders maintain double cavity chain structure regardless of the chromium doping. When the Cr doping of x = 0.03, capacity is highest. Maximum initial discharge capacity is 334mA•h/g, 80% of theoretical capacity. During discharge process there is 6.5 Li+ embedded in the Molecules of doping. After discharge cathode became Li6.5Cr0.03V6O13.

scholarly journals Enhanced Electrochemical Performances of Cobalt-Doped Li2MoO3 Cathode Materials

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 843 ◽  
Author(s):  
Zhiyong Yu ◽  
Jishen Hao ◽  
Wenji Li ◽  
Hanxing Liu
Keyword(s):  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Phase Method ◽  
Electrochemical Performances ◽  
X Ray ◽  
Electrochemical Tests ◽  
Co Doping ◽  
Solid Phase Method ◽  
Better Than

Co-doped Li2MoO3 was successfully synthesized via a solid phase method. The impacts of Co-doping on Li2MoO3 have been analyzed by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) measurements. The results show that an appropriate amount of Co ions can be introduced into the Li2MoO3 lattices, and they can reduce the particle sizes of the cathode materials. Electrochemical tests reveal that Co-doping can significantly improve the electrochemical performances of the Li2MoO3 materials. Li2Mo0.90Co0.10O3 presents a first-discharge capacity of 220 mAh·g−1, with a capacity retention of 63.6% after 50 cycles at 5 mA·g−1, which is much better than the pristine samples (181 mAh·g−1, 47.5%). The enhanced electrochemical performances could be due to the enhancement of the structural stability, and the reduction in impedance, due to the Co-doping.

Effects of Morphological Collapse of Sphere Secondary Particles on Electrochemical Properties of a LiNi0.83Co0.11Mn0.06O2 Cathode Material for Lithium-Ion Batteries

2020 ◽  
Vol 12 (9) ◽  
pp. 1278-1282
Author(s):  
Jun-Seok Park ◽  
Un-Gi Han ◽  
Gyu-Bong Cho ◽  
Hyo-Jun Ahn ◽  
Ki-Won Kim ◽  
...  
Keyword(s):  
Cathode Material ◽  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Solid Phase ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Phase Method ◽  
Electrochemical Characteristics ◽  
Secondary Particles ◽  
Tap Density

Li[NixCoyMnz]O2 (LiNCM) is one of the candidate cathode material that can replace the currently commercialized LiCoO2 (LCO) cathode material for lithium-ion batteries (LiBs). The morphological feature having primary particle and secondary sphere particle could affect structural stability, tap density and electrochemical performance of LiNCM. In this work, two LiNCM particles without or with the morphological collapse of the secondary particles were prepared by using a co-precipitation-assisted, solid-phase method and ball milling, and its morphological, structural and electrochemical characteristics were evaluated. The results of XRD, and FESEM demonstrated that the as-prepared two LiNCMs have a typical α-NaFeO2 layered structure and the two morphological features of secondary particles needed in this study. The results of electrochemical properties indicated that the LiNCM electrode without collapsed secondary particles have a good stability in cycle performance compared to that with collapse of secondary particles at 0.5, 1.0 and 2 C-rate. The capacity retention of without and with collapsed NCM was 55.8% and 27.3% after 200 cycles at 1 C-rate, respectively.

Effects of Sintering Temperatures on the Solid-Phase Synthesis of Lithium Vanadium Phosphate for Lithium-Ion Cathode Materials

2013 ◽  
Vol 423-426 ◽  
pp. 541-544 ◽  
Author(s):  
Dao Wu Shuang Shi ◽  
Wei Wang ◽  
Zheng Zhang ◽  
Xing Quan Liu
Keyword(s):  
Cathode Material ◽  
Electrochemical Properties ◽  
Sintering Temperature ◽  
Solid Phase ◽  
Lithium Ion ◽  
Composite Cathode ◽  
Raw Material ◽  
Lithium Vanadium Phosphate ◽  
Composite Cathode Material ◽  
Coated Carbon

Li3V2(PO4)3/C composite cathode material was prepared by carbothermal reduction using LiOHH2O, NH4H2PO4, NH4VO3 as raw material, sucrose as a coated carbon source, respectively. The electrochemical properties of Li3V2(PO4)3/C composite material prepared at different sintering temperature between 750°C and 900°C were investigated. The results demonstrated that by adjusting the sintering temperature, the electrochemical performance of the Li3V2(PO4)3/C material tends to be excellent, and when the temperature reaches 750°C, the Li3V2(PO4)3/C composite cathode material with the best electrochemical properties can be obtained.

Synthesis and Electrochemical Performance of LiFe1-xMnxPO4/C Cathode Material

2011 ◽  
Vol 347-353 ◽  
pp. 3434-3438
Author(s):  
Yan Jun Wei ◽  
Guang Chuan Liang ◽  
Li Wang ◽  
Xiu Qin Ou
Keyword(s):  
High Temperature ◽  
Electrochemical Performance ◽  
Cathode Material ◽  
Electrochemical Properties ◽  
Specific Energy ◽  
Solid Phase ◽  
Constant Current ◽  
Phase Method ◽  
Solid Phase Method ◽  
Constant Current Charging

Olivine LiFe1−xMnxPO4/C composites were prepared by high temperature solid phase method using MnO2, NH4H2PO4, Li2CO3, FeC2O4•2H2O, glucose as the starting materials. XRD, SEM and constant-current charging/discharging tests were used to study the structure and electrochemical properties of the material. The result showed that when x=0.2 the material exhibited the optimal electrochemical performance, with a higher specific energy of 484.94 Wh/kg.

Research on Electrochemical Properties of LiMnPO4 Synthesized by High Temperature Solid-Phase Method

2012 ◽  
Vol 487 ◽  
pp. 714-718 ◽  
Author(s):  
Sheng Kui Zhong ◽  
Ying Mei Zhang ◽  
Wei Li ◽  
Yue Bin Xu
Keyword(s):  
High Temperature ◽  
Solid Phase ◽  
Raw Materials ◽  
Particle Surface ◽  
Lithium Ion ◽  
Xrd Analysis ◽  
Spherical Particles ◽  
Phase Method ◽  
Solid Phase Method ◽  
Olivine Structure

LiMnPO4cathode material for lithium ion batteries was synthesized by high temperature solid-phase method using MnCO3, Li2CO3, NH4H2PO4as raw materials. The structure of samples was identified by XRD analysis and the particle surface morphology was examined by SEM. The results of XRD showed that the LiMnPO4sample sintered at 700°C for 20h had single ordered olivine structure. The SEM pattern showed that spherical particles distributed uniformly. Respectively, it figured out that the initial charge and discharge capacities of the samples at 0.05C rate were 133.9 and 66.4mAh•g-1.

scholarly journals Improved Electrochemical Properties of LiMn2O4-Based Cathode Material Co-Modified by Mg-Doping and Octahedral Morphology

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2807 ◽  
Author(s):  
Hongyuan Zhao ◽  
Yongfang Nie ◽  
Dongyang Que ◽  
Youzuo Hu ◽  
Yongfeng Li
Keyword(s):  
High Temperature ◽  
Cathode Material ◽  
Electrochemical Properties ◽  
Solid Phase ◽  
High Capacity ◽  
Temperature Cycling ◽  
Phase Method ◽  
Mg Doping ◽  
Jahn Teller ◽  
Solid Phase Method

In this work, the spinel LiMn2O4 cathode material was prepared by high-temperature solid-phase method and further optimized by co-modification strategy based on the Mg-doping and octahedral morphology. The octahedral LiMn1.95Mg0.05O4 sample belongs to the spinel cubic structure with the space group of Fd3m, and no other impurities are presented in the XRD patterns. The octahedral LiMn1.95Mg0.05O4 particles show narrow size distribution with regular morphology. When used as cathode material, the obtained LiMn1.95Mg0.05O4 octahedra shows excellent electrochemical properties. This material can exhibit high capacity retention of 96.8% with 100th discharge capacity of 111.6 mAh g−1 at 1.0 C. Moreover, the rate performance and high-temperature cycling stability of LiMn2O4 are effectively improved by the co-modification strategy based on Mg-doping and octahedral morphology. These results are mostly given to the fact that the addition of magnesium ions can suppress the Jahn–Teller effect and the octahedral morphology contributes to the Mn dissolution, which can improve the structural stability of LiMn2O4.

Preparation of ZnNb2O6 Powders by Molten Salt Method

2011 ◽  
Vol 412 ◽  
pp. 94-98
Author(s):  
Dai Bing Zhang ◽  
Guo You Gan ◽  
Ji Kang Yan ◽  
Zhong Wen Chen ◽  
Jing Hong Du ◽  
...  
Keyword(s):  
Particle Size ◽  
Molten Salt ◽  
Solid Phase ◽  
Raw Material ◽  
Narrow Particle Size Distribution ◽  
Phase Method ◽  
Molten Salt Method ◽  
Mass Ratio ◽  
Solid Phase Method ◽  
Special Direction

ZnNb2O6powders were prepared by solid phase method and molten salt method. KCl-NaCl-ZnCl2was used as molten salt. The mass ratio of molten salt and raw material is 1:1. Pure ZnNb2O6powders were synthesized by molten salt method? at 650°C, which was reduced by 200°C relative to solid phase method. ZnNb2O6powders preferably grow along special direction, and appear strip or rod like. ZnNb2O6powders calcined at 650°C have narrow particle size distribution. Median size D50 =5.31μm. With the increase of the calcining temperature grain grows and particle size increases.

Electrochemical Properties of LiMnPO4 Cathode Material Prepared by Ball-Milling

2012 ◽  
Vol 487 ◽  
pp. 735-738
Author(s):  
Sheng Kui Zhong ◽  
Yue Bin Xu ◽  
Wei Li ◽  
Wei Chen
Keyword(s):  
Cathode Material ◽  
Ball Milling ◽  
Solid Phase ◽  
Lithium Ion ◽  
Spherical Particles ◽  
Phase Method ◽  
Sem Images ◽  
Initial Charge ◽  
Solid Phase Method ◽  
Olivine Structure

The ball-milling LiMnPO4 powders for lithium-ion batteries were synthesized by high temperature solid-phase method. The effects of ball-milling on the microstructure and electrochemical performance of LiMnPO4 cathode material were investigated. The XRD patterns showed that the LiMnPO4 sample with ball milling 20h had single ordered olivine structure. The SEM images revealed that spherical particles distributed uniformly. The LiMnPO4 powders, of which the initial charge and discharge capacities at 0.05C rate were 133.9 and 66.4mAh•g-1 at 0.05C rate were prepared at 700°C for 20h with ball milling 20h.

scholarly journals Modeling electrochemical properties of LiMn$$_{1-x}$$Co$$_{x}$$BO$$_3$$ for cathode materials in lithium-ion rechargeable batteries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sérgio Leonardo Nhapulo ◽  
Jailton Souza de Almeida
Keyword(s):  
Electrochemical Properties ◽  
Cathode Materials ◽  
Density Functional ◽  
Lithium Ion ◽  
Rechargeable Batteries ◽  
Theoretical Description ◽  
Open Circuit ◽  
Discharge Process ◽  
Generalized Gradient ◽  
Metallic Behavior

AbstractIn this work, we report first-principle calculations of the electrochemical properties of lithitated and delithiated LiMn$$_{1-x}$$ 1 - x Co$$_{x}$$ x BO$$_3$$ 3 ($$x = 0$$ x = 0 , 0.25, 0.5, 0.75, 1) crystals based on the density functional theory (DFT) with the generalized gradient approximation (GGA) and also considering the on-site Coulomb interaction, the so-called Hubbard correction. We found that the top of the valence band and the bottom of the conduction band of these crystals are mainly formed by the hybridization of the 3d orbitals of mixed Mn$$_{1-x}$$ 1 - x Co$$_{x}$$ x ions and oxygen 2p orbitals. We observed a band gap narrowing with an increase of cobalt concentration and that the Hubbard correction implies a better theoretical description of their electronic structures. When considering the delithiated materials, our calculations show a metallic behavior for intermediate cobalt concentrations ($$x = 0.25$$ x = 0.25 , 0.5, 0.75), which is a good quality for cathodic materials, as it improves the battery discharge process. We also obtained high (4.14 V vs. Li$$^+$$ + /Li$$^0$$ 0 and 4.16 V vs. Li$$^+$$ + /Li$$^0$$ 0 ) open circuit voltage (OCV) values at cobalt concentrations of $$x = 0.5$$ x = 0.5 and 0.75, where we believe that if these high OCV values are accompanied by a high charge storage capacity, these compounds can become promising and useful cathode materials. Finally, our results are in accordance with previous calculations and also with experimental results.

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