scholarly journals Improving Electrochemical Performance at Graphite Negative Electrodes in Concentrated Electrolyte Solutions by Addition of 1,2-Dichloroethane

2019 ◽  
Vol 9 (21) ◽  
pp. 4647
Author(s):  
Hee-Youb Song ◽  
Moon-Hyung Jung ◽  
Soon-Ki Jeong

In concentrated propylene carbonate (PC)-based electrolyte solutions, reversible lithium intercalation and de-intercalation occur at graphite negative electrodes because of the low solvation number. However, concentrated electrolyte solutions have low ionic conductivity due to their high viscosity, which leads to poor electrochemical performance in lithium-ion batteries. Therefore, we investigated the effect of the addition of 1,2-dichloroethane (DCE), a co-solvent with low electron-donating ability, on the electrochemical properties of graphite in a concentrated PC-based electrolyte solution. An effective solid electrolyte interphase (SEI) was formed, and lithium intercalation into graphite occurred in the concentrated PC-based electrolyte solutions containing various amounts of DCE, while the reversible capacity improved. Raman spectroscopy results confirmed that the solvation structure of the lithium ions, which allows for effective SEI formation, was maintained despite the decrease in the total molality of LiPF6 by the addition of DCE. These results suggest that the addition of a co-solvent with low electron-donating ability is an effective strategy for improving the electrochemical performance in concentrated electrolyte solutions.

NANO ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. 1950155
Author(s):  
Yayi Cheng ◽  
Jianfeng Huang ◽  
Liyun Cao ◽  
Yongfeng Wang ◽  
Ying Ma ◽  
...  

SnSe2 and SnSe nanocrystals were prepared using a simple solvothermal method by changing the molar ratio of SnCl[Formula: see text]2H2O and Se powder. When SnSe2 and SnSe are acted as lithium ion battery anodes, the SnSe hybrid structure shows more excellent electrochemical performance than that of SnSe2 interconnected nanosheet. It delivers a reversible capacity of 1023[Formula: see text]mAh[Formula: see text]g[Formula: see text] at a current density of 200[Formula: see text]mA[Formula: see text]g[Formula: see text], and maintaining a capacity of 498[Formula: see text]mAh[Formula: see text]g[Formula: see text] till 120 cycles. According to many present works, SnSe2 with interconnected thin nanosheet should possess more superior property than hybrid structured SnSe due to short charge transfer paths. However, in our research, the result is the opposite. Therefore, we consider that the superior electrochemical performance of SnSe is attributed to its highly reversible conversion reaction mechanism than SnSe2.


2016 ◽  
Vol 09 (02) ◽  
pp. 1650027 ◽  
Author(s):  
Yongli Cui ◽  
Jiali Wang ◽  
Mingzhen Wang ◽  
Quanchao Zhuang

Shell spinel LiNi[Formula: see text]Mn[Formula: see text]O4 hollow microspheres were successfully synthesized by MnCO3 template, and characterized by XRD, SEM, and TEM. The results show that the hollow LiNi[Formula: see text]Mn[Formula: see text]O4 cathode has good cycle stability to reach 124.5, 119.8, and 96.6[Formula: see text]mAh/g at 0.5, 1, and 5 C, the corresponding retention rate of 98.1%, 98.2%, and 98.0% after 50 cycles at 20[Formula: see text]C, and the reversible capacity of 94.6[Formula: see text]mAh/g can be obtained at 1 C rate at 55[Formula: see text]C, 83.3% retention after 100 cycles. As the temperature decreases from 10[Formula: see text]C to [Formula: see text]C, the resistance of [Formula: see text] increases from 5.5 [Formula: see text] to 135 [Formula: see text], [Formula: see text] from 27 [Formula: see text] to 353.2 [Formula: see text], and [Formula: see text] from 12.7 [Formula: see text] to 73.0 [Formula: see text]. Moreover, the B constant and [Formula: see text] activation energy are 4480[Formula: see text]K and 37.22[Formula: see text]KJ/mol for the NTC spinel material, respectively.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Lihua Chu ◽  
Meicheng Li ◽  
Yu Wang ◽  
Xiaodan Li ◽  
Zipei Wan ◽  
...  

Graphene-based nanocomposites attract many attentions because of holding promise for many applications. In this work, multishelled NiO hollow spheres decorated by graphene nanosheets nanocomposite are successfully fabricated. The multishelled NiO microspheres are uniformly distributed on the surface of graphene, which is helpful for preventing aggregation of as-reduced graphene sheets. Furthermore, the NiO/graphene nanocomposite shows much higher electrochemical performance with a reversible capacity of 261.5 mAh g−1at a current density of 200 mA g−1after 100 cycles tripled compared with that of pristine multishelled NiO hollow spheres, implying the potential application in modern science and technology.


RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6660-6666 ◽  
Author(s):  
Jun Wang ◽  
Shengli Li ◽  
Yi Zhao ◽  
Juan Shi ◽  
Lili Lv ◽  
...  

With a high specific capacity (4200 mA h g−1), silicon based materials have become the most promising anode materials in lithium-ions batteries.


2018 ◽  
Vol 6 (25) ◽  
pp. 11688-11693 ◽  
Author(s):  
Lijiang Zhao ◽  
Shitong Wang ◽  
Feng Pan ◽  
Zilong Tang ◽  
Zhongtai Zhang ◽  
...  

TiO2 microclew filled carbon cloth favours fast transport of lithium ions and electrons, causing high electrochemical performance.


2013 ◽  
Vol 1540 ◽  
Author(s):  
Chia-Yi Lin ◽  
Chien-Te Hsieh ◽  
Ruey-Shin Juang

ABSTRACTAn efficient microwave-assisted polyol (MP) approach is report to prepare SnO2/graphene hybrid as an anode material for lithium ion batteries. The key factor to this MP method is to start with uniform graphene oxide (GO) suspension, in which a large amount of surface oxygenate groups ensures homogeneous distribution of the SnO2 nanoparticles onto the GO sheets under the microwave irradiation. The period for the microwave heating only takes 10 min. The obtained SnO2/graphene hybrid anode possesses a reversible capacity of 967 mAh g-1 at 0.1 C and a high Coulombic efficiency of 80.5% at the first cycle. The cycling performance and the rate capability of the hybrid anode are enhanced in comparison with that of the bare graphene anode. This improvement of electrochemical performance can be attributed to the formation of a 3-dimensional framework. Accordingly, this study provides an economical MP route for the fabrication of SnO2/graphene hybrid as an anode material for high-performance Li-ion batteries.


NANO ◽  
2019 ◽  
Vol 14 (03) ◽  
pp. 1950037 ◽  
Author(s):  
Bingning Wang ◽  
Xuehua Liu ◽  
Binghui Xu ◽  
Yanhui Li ◽  
Dan Xiu ◽  
...  

Three-dimensional reduced graphene oxide (RGO) matrix decorated with nanoflowers of layered MoS2 (denoted as 3D MoS2/RGO) have been synthesized via a facile one-pot stepwise hydrothermal method. Graphene oxide (GO) is used as precursor of RGO and a 3D GO network is formed in the first-step of hydrothermal treatment. At the second stage of hydrothermal treatment, nanoflowers of layered MoS2 form and anchor on the surface of previously formed 3D RGO network. In this preparation, thiourea not only induces the formation of the 3D architecture at a relatively low temperature, but also works as sulfur precursor of MoS2. The synthesized composites have been investigated with XRD, SEM, TEM, Raman spectra, TGA, N2 sorption technique and electrochemical measurements. In comparison with normal MoS2/RGO composites, the 3D MoS2/RGO composite shows improved electrochemical performance as anode material for lithium-ion batteries. A high reversible capacity of 930[Formula: see text]mAh[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] after 130 cycles under a current density of 200[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] as well as good rate capability and superior cyclic stability have been observed. The superior electrochemical performance of the 3D MoS2/RGO composite as anode active material for lithium-ion battery is ascribed to its robust 3D structures, enhanced surface area and the synergistic effect between graphene matrix and the MoS2 nanoflowers subunit.


2015 ◽  
Vol 3 (34) ◽  
pp. 17713-17720 ◽  
Author(s):  
Li Liu ◽  
Taeseup Song ◽  
Hyungkyu Han ◽  
Hyunjung Park ◽  
Juan Xiang ◽  
...  

Porous LiMnPO4/C composite nanofibers show excellent electrochemical performance including a high reversible capacity of 112.7 mA h g−1 and stable cycle retention of 95% after 100 cycles.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1336 ◽  
Author(s):  
Thang Phan Nguyen ◽  
Il Tae Kim

Recently, composites of MXenes and two-dimensional transition metal dichalcogenides have emerged as promising materials for energy storage applications. In this study, W2C/WS2 alloy nanoflowers (NFs) were prepared by a facile hydrothermal method. The alloy NFs showed a particle size of 200 nm–1 μm, which could be controlled. The electrochemical performance of the as-prepared alloy NFs was investigated to evaluate their potential for application as lithium-ion battery (LIB) anodes. The incorporation of W2C in the WS2 NFs improved their electronic properties. Among them, the W2C/WS2_4h NF electrode showed the best electrochemical performance with an initial discharge capacity of 1040 mAh g−1 and excellent cyclability corresponding to a reversible capacity of 500 mAh g−1 after 100 cycles compared to that of the pure WS2 NF electrode. Therefore, the incorporation of W2C is a promising approach to improve the performance of LIB anode materials.


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