scholarly journals Enhanced Cycle Stability of Zinc Sulfide Anode for High-Performance Lithium-Ion Storage: Effect of Conductive Hybrid Matrix on Active ZnS

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.

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.


Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1467
Author(s):  
Xuanni Lin ◽  
Zhuoyi Yang ◽  
Anru Guo ◽  
Dong Liu

High energy density batteries with high performance are significantly important for intelligent electrical vehicular systems. Iron sulfurs are recognized as one of the most promising anodes for high energy density lithium-ion batteries because of their high theoretical specific capacity and relatively stable electrochemical performance. However, their large-scale commercialized application for lithium-ion batteries are plagued by high-cost and complicated preparation methods. Here, we report a simple and cost-effective method for the scalable synthesis of nanoconfined FeS in porous carbon (defined as FeS@C) as anodes by direct pyrolysis of an iron(III) p-toluenesulfonate precursor. The carbon architecture embedded with FeS nanoparticles provides a rapid electron transport property, and its hierarchical porous structure effectively enhances the ion transport rate, thereby leading to a good electrochemical performance. The resultant FeS@C anodes exhibit high reversible capacity and long cycle life up to 500 cycles at high current density. This work provides a simple strategy for the mass production of FeS@C particles, which represents a critical step forward toward practical applications of iron sulfurs anodes.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 920
Author(s):  
Tiantian Yang ◽  
Hangjun Ying ◽  
Shunlong Zhang ◽  
Jianli Wang ◽  
Zhao Zhang ◽  
...  

Silicon is investigated as one of the most prospective anode materials for next generation lithium ion batteries due to its superior theoretical capacity (3580 mAh g−1), but its commercial application is hindered by its inferior dynamic property and poor cyclic performance. Herein, we presented a facile method for preparing silicon/tin@graphite-amorphous carbon (Si/Sn@G–C) composite through hydrolyzing of SnCl2 on etched Fe–Si alloys, followed by ball milling mixture and carbon pyrolysis reduction processes. Structural characterization indicates that the nano-Sn decorated porous Si particles are coated by graphite and amorphous carbon. The addition of nano-Sn and carbonaceous materials can effectively improve the dynamic performance and the structure stability of the composite. As a result, it exhibits an initial columbic efficiency of 79% and a stable specific capacity of 825.5 mAh g−1 after 300 cycles at a current density of 1 A g−1. Besides, the Si/Sn@G–C composite exerts enhanced rate performance with 445 mAh g−1 retention at 5 A g−1. This work provides an approach to improve the electrochemical performance of Si anode materials through reasonable compositing with elements from the same family.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 307
Author(s):  
Caroline Keller ◽  
Antoine Desrues ◽  
Saravanan Karuppiah ◽  
Eléa Martin ◽  
John Alper ◽  
...  

Silicon is a promising material for high-energy anode materials for the next generation of lithium-ion batteries. The gain in specific capacity depends highly on the quality of the Si dispersion and on the size and shape of the nano-silicon. The aim of this study is to investigate the impact of the size/shape of Si on the electrochemical performance of conventional Li-ion batteries. The scalable synthesis processes of both nanoparticles and nanowires in the 10–100 nm size range are discussed. In cycling lithium batteries, the initial specific capacity is significantly higher for nanoparticles than for nanowires. We demonstrate a linear correlation of the first Coulombic efficiency with the specific area of the Si materials. In long-term cycling tests, the electrochemical performance of the nanoparticles fades faster due to an increased internal resistance, whereas the smallest nanowires show an impressive cycling stability. Finally, the reversibility of the electrochemical processes is found to be highly dependent on the size/shape of the Si particles and its impact on lithiation depth, formation of crystalline Li15Si4 in cycling, and Li transport pathways.


2014 ◽  
Vol 809-810 ◽  
pp. 781-786
Author(s):  
Min Liu ◽  
Na Zhang ◽  
Feng Hui Zhao ◽  
Xiao Qin Zhao ◽  
Ke Chen ◽  
...  

As lithium-ion battery anode materials, silicon has the highest specific capacity. In order to restrain pure silicon’s serious volume change and enhance its electrochemical performance, Si/SiO2 composites were prepared by using a convenient high energy ball-milling technique. The characteristics of the composites as anode material for rechargeable lithium-ion batteries were investigated by X-ray diffraction and scanning electron microscopy methods. The electrochemical performance of the anode material was studied, and it was found the composite anode had a high capacity of 1333 mAhg-1 in the first cycle and 400 mAhg-1 could still be obtained after 46 cycles. Such prepared materials displayed improved cycle life.


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.


Author(s):  
Meili Qi ◽  
Hengxu Wang ◽  
Jinghua Yin

Abstract High-energy density lithium ion batteries (LIBs) rely heavily on innovations of electrode materials. Herein, the porous TiNb2O7/carbon nanofibers (TNO/CNFs) have been prepared through the hydrothermal method and electrostatic spinning method as the anode for the Li-ion battery. The structure of porous TNO/CNFs after annealing at 700 °C for 2 h is intact, and lots of holes are found on that surface of nanofibers. Porous TNO/CNFs as the anode show better electrochemical performance than TNO/CNFs, the capacity retention of porous TNO/CNFs is 81.6% (147 mA h/g) with an exceptionally high rate (at 20 C rate). And the capacity retention of porous TNO/CNFs is higher than ≈77% that of TNO/CNFs (112 mA h/g). The superior electrochemical performance of these porous TNO/CNFs can be attributed to the unique porous carbon nanofiber structure: this structure of porous nanofibers not only provides a larger effective area for contact with the electrolyte but also reduces the rate-limiting Li diffusion path, leading to faster charge transfer.


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


2021 ◽  
Vol 10 (1) ◽  
pp. 210-220
Author(s):  
Fangfang Wang ◽  
Ruoyu Hong ◽  
Xuesong Lu ◽  
Huiyong Liu ◽  
Yuan Zhu ◽  
...  

Abstract The high-nickel cathode material of LiNi0.8Co0.15Al0.05O2 (LNCA) has a prospective application for lithium-ion batteries due to the high capacity and low cost. However, the side reaction between the electrolyte and the electrode seriously affects the cycling stability of lithium-ion batteries. In this work, Ni2+ preoxidation and the optimization of calcination temperature were carried out to reduce the cation mixing of LNCA, and solid-phase Al-doping improved the uniformity of element distribution and the orderliness of the layered structure. In addition, the surface of LNCA was homogeneously modified with ZnO coating by a facile wet-chemical route. Compared to the pristine LNCA, the optimized ZnO-coated LNCA showed excellent electrochemical performance with the first discharge-specific capacity of 187.5 mA h g−1, and the capacity retention of 91.3% at 0.2C after 100 cycles. The experiment demonstrated that the improved electrochemical performance of ZnO-coated LNCA is assigned to the surface coating of ZnO which protects LNCA from being corroded by the electrolyte during cycling.


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