scholarly journals Sucrose-Assisted Synthesis of Layered Lithium-Rich Oxide Li[Li0.2Mn0.56Ni0.16Co0.08]O2 as a Cathode of Lithium-Ion Battery

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 436 ◽  
Author(s):  
Song ◽  
Huang ◽  
Zhong

:Herein, the lithium-rich material Li[Li0.2Mn0.56Ni0.16Co0.08]O2 is successfully prepared by a sucrose-assisted gel method. With the assistance of sucrose, Li[Li0.2Mn0.56Ni0.16Co0.08]O2 precursors can be uniformly dispersed into sticky sucrose gel without aggregation. XRD shows that the lithium-rich material Li[Li0.2Mn0.56Ni0.16Co0.08]O2 has a well-organized layered structure. The electrochemical performance is influenced by calcination temperature. The results show that the sample Li[Li0.2Mn0.56Ni0.16Co0.08]O2 calcined at 900 °C possess significant performance. This sample delivers higher discharge specific capacity of 252 mAh g−1; rate capability with a capacity retention of 86% when tested at 5C; and excellent cyclic stability with a capacity retention rate of 81% after 100 cycles under 1C test. The sucrose-assisted method shows great potential in fabricating layered lithium-rich materials

2019 ◽  
Vol 807 ◽  
pp. 74-81
Author(s):  
Ying Wang ◽  
Wei Ruan ◽  
Ren Heng Tang ◽  
Fang Ming Xiao ◽  
Tai Sun ◽  
...  

In this study, Si@C/Graphite composite anodes were synthesized through spray drying and pyrolysis using silica, artificial graphite, and two kinds of organics (phenolic resin or pitch). The Si@PR-C/Graphite exhibits enhanced electrochemical performance for lithium-ion batteries. The first charge-discharge specific capacity is 512.8mAh/g and 621.8mAh/g, respectively, the initial coulombic efficiency is 82.5% at 100mA/g, and its capacity retention rate reached as high as 85.4% with the capacity fade rate of less than 0.18% per cycle after 85 cycles. The Si@PI-C/Graphite also presents excellent discharge specific capacity of 702.8mAh/g with the capacity retention rate of 76.9% after 30 cycles. Mechanisms for high electrochemical performances of the Si@C/Graphite composite anode are discussed. It found that the enhanced electrochemical performance due to the formation of core/shell microstructure. These encouraging experimental results suggest that proper organic carbon source has great potential for improvement of electrochemical properties of pure silicon as anode. Key words:lithium-ion batteries; anode; Si@C/Graphite composite; electrochemical performance


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.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiangmin Jiang ◽  
Guangdi Nie ◽  
Ping Nie ◽  
Zhiwei Li ◽  
Zhenghui Pan ◽  
...  

AbstractAmong the various morphologies of carbon-based materials, hollow carbon nanostructures are of particular interest for energy storage. They have been widely investigated as electrode materials in different types of rechargeable batteries, owing to their high surface areas in association with the high surface-to-volume ratios, controllable pores and pore size distribution, high electrical conductivity, and excellent chemical and mechanical stability, which are beneficial for providing active sites, accelerating electrons/ions transfer, interacting with electrolytes, and giving rise to high specific capacity, rate capability, cycling ability, and overall electrochemical performance. In this overview, we look into the ongoing progresses that are being made with the nanohollow carbon materials, including nanospheres, nanopolyhedrons, and nanofibers, in relation to their applications in the main types of rechargeable batteries. The design and synthesis strategies for them and their electrochemical performance in rechargeable batteries, including lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, and lithium–sulfur batteries are comprehensively reviewed and discussed, together with the challenges being faced and perspectives for them.


2019 ◽  
Author(s):  
Panpan Wang ◽  
Yue Du ◽  
Baoyou Zhang ◽  
Yanxin Yao ◽  
Yuchen Xiao ◽  
...  

The <i>β-</i>phase lithium vanadium oxide bronze (<i>β-</i>Li<i><sub>x</sub></i>V<sub>2</sub>O<sub>5</sub>) with high theoretic specific capacity up to 440 mAh g<sup>-1</sup> is considered as promising cathode materials, however, their practical application is hindered by its poor ionic and electronic conductivity, resulting in unsatisfied cyclic stability and rate capability. Herein, we report the surface decoration of <i>β-</i>Li<i><sub>x</sub></i>V<sub>2</sub>O<sub>5</sub> cathode using both reduced oxide graphene and ionic conductor LaPO<sub>4</sub>, which significantly promotes the electronic transfer and Li<sup>+</sup> diffusion rate, respectively. As a result, the rGO/LaPO<sub>4</sub>/Li<i><sub>x</sub></i>V<sub>2</sub>O<sub>5</sub> composite exhibits excellent electrochemical performance in terms of high reversible specific capacity of 275.7 mAh g<sup>-1</sup> with high capacity retention of 84.1% after 100 cycles at a current density of 60 mA g<sup>-1</sup>, and acceptable specific capacity of 170.3 mAh g<sup>-1</sup> at high current density of 400 mA g<sup>-1</sup>. The cycled electrode is also analyzed by electrochemical impedance spectroscopy, <i>ex-situ </i>X-ray diffraction and scanning electron microscope, providing further insights into the improvement of electrochemical performance. Our results provide an effective approach to boost the electrochemical properties of lithium vanadates for practical application in lithium ion batteries.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4751
Author(s):  
Lian-Bang Wang ◽  
He-Shan Hu ◽  
Wei Lin ◽  
Qing-Hong Xu ◽  
Jia-Dong Gong ◽  
...  

Lithium-rich manganese oxide is a promising candidate for the next-generation cathode material of lithium-ion batteries because of its low cost and high specific capacity. Herein, a series of xLi2MnO3·(1 − x)LiMnO2 nanocomposites were designed via an ingenious one-step dynamic hydrothermal route. A high concentration of alkaline solution, intense hydrothermal conditions, and stirring were used to obtain nanoparticles with a large surface area and uniform dispersity. The experimental results demonstrate that 0.072Li2MnO3·0.928LiMnO2 nanoparticles exhibit a desirable electrochemical performance and deliver a high capacity of 196.4 mAh g−1 at 0.1 C. This capacity was maintained at 190.5 mAh g−1 with a retention rate of 97.0% by the 50th cycle, which demonstrates the excellent cycling stability. Furthermore, XRD characterization of the cycled electrode indicates that the Li2MnO3 phase of the composite is inert, even under a high potential (4.8 V), which is in contrast with most previous reports of lithium-rich materials. The inertness of Li2MnO3 is attributed to its high crystallinity and few structural defects, which make it difficult to activate. Hence, the final products demonstrate a favorable electrochemical performance with appropriate proportions of two phases in the composite, as high contents of inert Li2MnO3 lower the capacity, while a sufficient structural stability cannot be achieved with low contents. The findings indicate that controlling the composition through a dynamic hydrothermal route is an effective strategy for developing a Mn-based cathode material for lithium-ion batteries.


2021 ◽  
Author(s):  
Fengling Chen ◽  
Jiannan Lin ◽  
Yifan Chen ◽  
Binbin Dong ◽  
Chujun Yin ◽  
...  

Abstract Nickel-rich cathode materials are increasingly being applied in commercial lithium-ion batteries to realize higher specific capacity as well as improve energy density. However, low structural stability and rapid capacity decay at high voltage and temperature hinder their rapid large-scale application. Herein, a wet chemical method followed by a post-annealing process is utilized to realize the surface coating of tantalum oxide on LiNi0.88Mn0.03Co0.09O2, and the electrochemical performance is improved. The modified LiNi0.88Mn0.03Co0.09O2 displays an initial discharge capacity of ~233 mAh/g at 0.1 C and 174 mAh/g at 1 C after 150 cycles in the voltage range of 3.0-4.4 V at 45 ℃, and it also exhibits an enhanced rate capability with 118 mAh/g at 5 C. The excellent performance is due to the introduction of tantalum oxide as a stable and functional layer to protect the surface of LiNi0.88Mn0.03Co0.09O2, and the surface side reactions and cation mixing are suppressed at the same time without hampering the charge transfer kinetics.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jianjun Song ◽  
Ying Zhang ◽  
Guangjie Shao

Supervalent cation doping and metal oxide coating are the most efficacious and popular methods to optimize the property of LiFePO4lithium battery material. Mg-doped and MgO-coated LiFePO4/C were synthesized to analyze their individual influence on the electrochemical performance of active material. The specific capacity and rate capability of LiFePO4/C are improved by both MgO coating and Mg doping, especially the Mg-doped sample—Li0.985Mg0.015FePO4/C, whose discharge capacity is up to 163 mAh g−1, 145.5 mAh g−1, 128.3 mAh g−1, and 103.7 mAh g−1at 1 C, 2 C, 5 C, and 10 C, respectively. The cyclic life of electrode is obviously increased by MgO surface modification, and the discharge capacity retention rate of sample LiFePO4/C-MgO2.5is up to 104.2% after 100 cycles. Comparing samples modified by these two methods, Mg doping is more prominent on prompting the capacity and rate capability of LiFePO4, while MgO coating is superior in terms of improving cyclic performance.


2019 ◽  
Vol 960 ◽  
pp. 238-243
Author(s):  
Ming Wang ◽  
Xue Ming Zhang ◽  
Ying Bo Wang ◽  
Li Li Cheng ◽  
Xue Lei Wang ◽  
...  

Spinel Li4Ti5O12 (LTO) doped with Mg2+ was synthesized by solid-phase reaction method. The Mg2+ doping quantity was 3%, 6%, 9%, and 12%, respectively. The structure and electrochemical performance of the prepared LTO composites were investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and galvanostatic charge-discharge tests. It was found that the doped Mg ion did not change the structure of Li4Ti5O12, and it was evenly distributed around Li4Ti5O12. When Mg2+ doping quantity increased from 3% to 12%, the internal resistance and charge transfer resistance of the composite both decreased. The first discharge specific capacity of 6%-Mg2+ doped LTO composite was 168 mAh/g, which was close to the theoretical capacity of pure lithium titanate (175 mAh/g), and the capacity retention rate was 98% after 100 cycles.


2015 ◽  
Vol 3 (27) ◽  
pp. 14291-14297 ◽  
Author(s):  
Yi-di Zhang ◽  
Yi Li ◽  
Xiao-qing Niu ◽  
Dong-huang Wang ◽  
Ding Zhou ◽  
...  

A novel peanut-like hierarchical micro/nano-lithium-rich cathode material with superior cyclic stability and enhanced rate capability is synthesized via a solvothermal method.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1221 ◽  
Author(s):  
Quoc Hanh Nguyen ◽  
Taehyun Park ◽  
Jaehyun Hur

Zinc sulfide (ZnS) nanocrystallites embedded in a conductive hybrid matrix of titanium carbide and carbon, are successfully fabricated via a facile high-energy ball-milling (HEBM) process. The structural and morphological analyses of the ZnS-TiC-C nanocomposites reveal that ZnS and TiC nanocrystallites are homogeneously distributed in an amorphous carbon matrix. Compared with ZnS-C and ZnS composites, the ZnS-TiC-C nanocomposite exhibits significantly improved electrochemical performance, delivering a highly reversible specific capacity (613 mA h g−1 over 600 cycles at 0.1 A g−1, i.e., ~85% capacity retention), excellent long-term cyclic performance (545 mA h g−1 and 467 mA h g−1 at 0.5 A g−1 and 1 A g−1, respectively, after 600 cycles), and good rate capability at 10 A g−1 (69% capacity retention at 0.1 A g−1). The electrochemical performance is significantly improved, primarily owing to the presence of conductive hybrid matrix of titanium carbide and amorphous carbon in the ZnS-TiC-C nanocomposites. The matrix not only provides high conductivity but also acts as a mechanical buffering matrix preventing huge volume changes during prolonged cycling. The lithiation/delithiation mechanisms of the ZnS-TiC-C electrodes are examined via ex situ X-ray diffraction (XRD) analysis. Furthermore, to investigate the practical application of the ZnS-TiC-C nanocomposite, a coin-type full cell consisting of a ZnS-TiC-C anode and a LiFePO4–graphite cathode is assembled and characterized. The cell exhibits excellent cyclic stability up to 200 cycles and a good rate performance. This study clearly demonstrates that the ZnS-TiC-C nanocomposite can be a promising negative electrode material for the next-generation lithium-ion batteries.


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