scholarly journals Improved Electrochemical Performance of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 Cathode Material Synthesized by the Polyvinyl Alcohol Auxiliary Sol-Gel Process for Lithium-Ion Batteries

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
He Wang ◽  
Mingning Chang ◽  
Yonglei Zheng ◽  
Ningning Li ◽  
Siheng Chen ◽  
...  

A lithium-rich manganese-based cathode material, Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2, was prepared using a polyvinyl alcohol (PVA)-auxiliary sol-gel process using MnO2 as a template. The effect of the PVA content (0.0–15.0 wt%) on the electrochemical properties and morphology of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 was investigated. Analysis of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 X-ray diffraction patterns by RIETAN-FP program confirmed the layered α-NaFeO2 structure. The discharge capacity and coulombic efficiency of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 in the first cycle were improved with increasing PVA content. In particular, the best material reached a first discharge capacity of 206.0 mAhg−1 and best rate capability (74.8 mAhg−1 at 5 C). Meanwhile, the highest capacity retention was 87.7% for 50 cycles. Finally, electrochemical impedance spectroscopy shows that as the PVA content increases, the charge-transfer resistance decreases.

Author(s):  
Atef Y. Shenouda ◽  
M. M. S. Sanad

Li2NixFe1−xSiO4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) samples were prepared by sol–gel process. The crystal structure of prepared samples of Li2NixFe1−xSiO4 was characterized by XRD. The different crystallographic parameters such as crystallite size and lattice cell parameters have been calculated. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) investigations were carried out explaining the morphology and function groups of the synthesized samples. Furthermore, electrochemical impedance spectra (EIS) measurements are applied. The obtained results indicated that the highest conductivity is achieved for Li2Ni0.4Fe0.6SiO4 electrode compound. It was observed that Li/Li2Ni0.4Fe0.6SiO4 battery has initial discharge capacity of 164 mAh g−1 at 0.1 C rate. The cycle life performance of all Li2NixFe1−xSiO4 batteries was ranged between 100 and 156 mAh g−1 with coulombic efficiency range between 70.9% and 93.9%.


MRS Advances ◽  
2016 ◽  
Vol 1 (45) ◽  
pp. 3063-3068
Author(s):  
Mónica López de Victoria ◽  
Loraine Torres-Castro ◽  
Rajesh K. Katiyar ◽  
Jifi Shojan ◽  
Valerio Dorvilien ◽  
...  

ABSTRACTThe inclusion of a spinel structure in the layered-layered composite cathode material is currently explored to enhance the cycling stability and electrochemical properties of lithium ion batteries. Li2MnO3 based composite cathodes are one of the most widely investigated positive electrodes due to their high discharge capacity and rate capability. In our studies, we have synthesized the cobalt-free layered-layered-spinel composite cathode material, 0.5Li2MnO3-0.25LiMn2O4-0.25LiNi0.5Mn0.5O2 (LLNMO), via the sol-gel method. The structure of the composition was characterized using XRD and Raman Spectroscopy in which peaks corresponding to the layered and spinel structures were identified. The morphology along with the elemental analysis were studied with SEM/EDX. The SEM images exhibited agglomerates with particle size in the nano range and the EDX analysis confirmed the presence of manganese, nickel and oxygen in the structure. The electrochemical performance was analyzed by charge/discharge studies (CD) and cyclic voltammetry (CV). The composite cathode material showed high capacity retention and good cycle stability with a coulombic efficiency of 98%. The discussed results demonstrated that LLNMO is a promising cathode material for the next generation of Li-ion batteries.


RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 77324-77331 ◽  
Author(s):  
Qingliang Xie ◽  
Chenhao Zhao ◽  
Zhibiao Hu ◽  
Qi Huang ◽  
Cheng Chen ◽  
...  

Layered Li[Li0.2Mn0.56Ni0.16Co0.08]O2 porous microspheres have been successfully synthesized by a urea combustion method, and then coated with appropriate amount of LaPO4via a facile chemical precipitation route.


2003 ◽  
Vol 02 (04n05) ◽  
pp. 299-306 ◽  
Author(s):  
CHIEN-TE HSIEH ◽  
JIN-MING CHEN ◽  
HSIU-WEN HUANG

Nanostructured SnO 2/ C composites used as anode materials were prepared by sol–gel synthesis to explore electrochemical properties in lithium-ion batteries. Surface characteristics of the SnO 2/ C nanocomposite were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that nanocrystalline SnO 2/ C with a grain size of 20–50 nm was uniformly dispersed on the carbon surface. After nanocrytalline SnO 2 coated onto carbon, the discharge capacity showed an increase up to 23%, i.e., from 300 to 370 mAh/g at a current density of 0.6 mA/cm2. The nanocomposite anode can achieve a fairly stable discharge capacity and excellent Coulombic efficiency (>99.5%) over 50 cycles. Cyclic voltammograms indicated that the improvements on capacity and cycleability were due to reversible alloying of nanosized Sn and Li on carbon surface.


2020 ◽  
Vol 31 (21) ◽  
pp. 19475-19486
Author(s):  
Jeffin James Abraham ◽  
Umair Nisar ◽  
Haya Monawwar ◽  
Aisha Abdul Quddus ◽  
R. A. Shakoor ◽  
...  

AbstractLithium-rich layered oxides (LLOs) such as Li1.2Ni0.13Mn0.54Co0.13O2 are suitable cathode materials for future lithium-ion batteries (LIBs). Despite some salient advantages, like low cost, ease of fabrication, high capacity, and higher operating voltage, these materials suffer from low cyclic stability and poor capacity retention. Several different techniques have been proposed to address the limitations associated with LLOs. Herein, we report the surface modification of Li1.2Ni0.13Mn0.54Co0.13O2 by utilizing cheap and readily available silica (SiO2) to improve its electrochemical performance. Towards this direction, Li1.2Ni0.13Mn0.54Co0.13O2 was synthesized utilizing a sol–gel process and coated with SiO2 (SiO2 = 1.0 wt%, 1.5 wt%, and 2.0 wt%) employing dry ball milling technique. XRD, SEM, TEM, elemental mapping and XPS characterization techniques confirm the formation of phase pure materials and presence of SiO2 coating layer on the surface of Li1.2Ni0.13Mn0.54Co0.13O2 particles. The electrochemical measurements indicate that the SiO2-coated Li1.2Ni0.13Mn0.54Co0.13O2 materials show improved electrochemical performance in terms of capacity retention and cyclability when compared to the uncoated material. This improvement in electrochemical performance can be related to the prevention of electrolyte decomposition when in direct contact with the surface of charged Li1.2Ni0.13Mn0.54Co0.13O2 cathode material. The SiO2 coating thus prevents the unwanted side reactions between cathode material and the electrolyte. 1.0 wt% SiO2-coated Li1.2Ni0.13Mn0.54Co0.13O2shows the best electrochemical performance in terms of rate capability and capacity retention.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4565
Author(s):  
Sanghyuk Park ◽  
Kwangho Park ◽  
Ji-Seop Shin ◽  
Gyeongbin Ko ◽  
Wooseok Kim ◽  
...  

We firstly introduce Er and Ga co-doped swedenborgite-structured YBaCo4O7+δ (YBC) as a cathode-active material in lithium-ion batteries (LIBs), aiming at converting the phase instability of YBC at high temperatures into a strategic way of enhancing the structural stability of layered cathode-active materials. Our recent publication reported that Y0.8Er0.2BaCo3.2Ga0.8O7+δ (YEBCG) showed excellent phase stability compared to YBC in a fuel cell operating condition. By contrast, the feasibility of the LiCoO2 (LCO) phase, which is derived from swedenborgite-structured YBC-based materials, as a LIB cathode-active material is investigated and the effects of co-doping with the Er and Ga ions on the structural and electrochemical properties of Li-intercalated YBC are systemically studied. The intrinsic swedenborgite structure of YBC-based materials with tetrahedrally coordinated Co2+/Co3+ are partially transformed into octahedrally coordinated Co3+, resulting in the formation of an LCO layered structure with a space group of R-3m that can work as a Li-ion migration path. Li-intercalated YEBCG (Li[YEBCG]) shows effective suppression of structural phase transition during cycling, leading to the enhancement of LIB performance in Coulombic efficiency, capacity retention, and rate capability. The galvanostatic intermittent titration technique, cyclic voltammetry and electrochemical impedance spectroscopy are performed to elucidate the enhanced phase stability of Li[YEBCG].


RSC Advances ◽  
2016 ◽  
Vol 6 (34) ◽  
pp. 28729-28736 ◽  
Author(s):  
Kailing Sun ◽  
Can Peng ◽  
Zhaohui Li ◽  
Qichang Xiao ◽  
Gangtie Lei ◽  
...  

Core–shell Li1.2Mn0.54Co0.13Ni0.13O2@LiV3O8/C composite material was prepared by sol–gel method. It possessed an initial coulombic efficiency of 94% at 0.1C rate over 2.0–4.8 V potential range, and good rate capability and stable operation voltage.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yuxin Ma ◽  
Ping Cui ◽  
Dan Zhan ◽  
Bing Gan ◽  
Youliang Ma ◽  
...  

The graphene oxide-coated SnO2-Li1/3Co1/3Mn1/3O2 (GO-SnO2-NCM) cathode material was successfully synthesized via a facile wet chemical method. The pristine NCM and GO-SnO2-NCM were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that the double-coating layer did not destroy the NCM crystal structure, with multiple nano-SnO2 particles and GO uniformly covering the NCM surface. Electrochemical tests indicated that GO-SnO2-NCM exhibited excellent cycling performance, with 90.7% capacity retention at 1 C after 100 cycles, which was higher than 74.3% for the pristine NCM at the same cycle. The rate capability showed that the double-coating layer enhanced surface electronic–ionic transport. Electrochemical impedance spectroscopy results confirmed that the GO-SnO2-coating layer effectively suppressed the increased electrode polarization and charge transfer resistance during cycling.


2014 ◽  
Vol 07 (02) ◽  
pp. 1450010 ◽  
Author(s):  
Linsen Zhang ◽  
Qingling Bai ◽  
Linzhen Wang ◽  
Aiqin Zhang ◽  
Yong Zhang ◽  
...  

SrWO 4/graphene composite was synthesized via a sol–gel method. The morphology and structure of the products were analyzed by SEM, TEM and XRD. The electrochemical performances of SrWO 4/graphene composite were investigated by galvanostatic charge/discharge method, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the first cycle of the reversible specific capacity of SrWO 4/graphene composite can reach to 575.9 mAh g-1 at 50 mA g-1. The charge/discharge cycling study indicates that the SrWO 4/graphene composite was provided with excellent cycle performance and outstanding rate capability.


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