scholarly journals Enhanced Structural Integrity and Electrochemical Performance of AlPO4-Coated MoO2 Anode Material for Lithium-Ion Batteries

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
José I. López-Pérez ◽  
Edwin O. Ortiz-Quiles ◽  
Khaled Habiba ◽  
Mariel Jiménez-Rodríguez ◽  
Brad R. Weiner ◽  
...  

AlPO4 nanoparticles were synthesized via chemical deposition method and used for the surface modification of MoO2 to improve its structural stability and electrochemical performance. Structure and surface morphology of pristine and AlPO4-coated MoO2 anode material were characterized by electron microscopy imaging (SEM and TEM) and X-ray diffraction (XRD). AlPO4 nanoparticles were observed, covering the surface of MoO2. Surface analyses show that the synthesized AlPO4 is amorphous, and the surface modification with AlPO4 does not result in a distortion of the lattice structure of MoO2. The electrochemical properties of pristine and AlPO4-coated MoO2 were characterized in the voltage range of 0.01–2.5 V versus Li/Li+. Cyclic voltammetry studies indicate that the improvement in electrochemical performance of the AlPO4-coated anode material was attributed to the stabilization of the lattice structure during lithiation. Galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) studies reveal that the AlPO4 nanoparticle coating improves the rate capability and cycle stability and contributes toward decreasing surface layer and charge-transfer resistances. These results suggest that surface modification with AlPO4 nanoparticles suppresses the elimination of oxygen vacancies in the lattice structure during cycling, leading to a better rate performance and cycle life.

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.


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.


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.


2020 ◽  
Vol 8 ◽  
Author(s):  
Yanhong Xiang ◽  
Youliang Jiang ◽  
Saiqiu Liu ◽  
Jianhua Wu ◽  
Zhixiong Liu ◽  
...  

Well-dispersed Li-rich Mn-based 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2 nanoparticles with diameter ranging from 50 to 100 nm are synthesized by a hydrothermal method in the presence of N-hexyl pyridinium tetrafluoroborate ionic liquid ([HPy][BF4]). The microstructures and electrochemical performance of the prepared cathode materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical measurements. The XRD results show that the sample prepared by ionic-liquid-assisted hydrothermal method exhibits a typical Li-rich Mn-based pure phase and lower cation mixing. SEM and TEM images indicate that the extent of particle agglomeration of the ionic-liquid-assisted sample is lower compared to the traditional hydrothermal sample. Electrochemical test results indicate that the materials synthesized by ionic-liquid-assisted hydrothermal method exhibit better rate capability and cyclability. Besides, electrochemical impedance spectroscopy (EIS) results suggest that the charge transfer resistance of 0.5Li2MnO3· 0.5LiNi0.5Mn0.5O2 synthesized by ionic-liquid-assisted hydrothermal method is much lower, which enhances the reaction kinetics.


2018 ◽  
Vol 11 (04) ◽  
pp. 1850083 ◽  
Author(s):  
Hongyong Ouyang ◽  
Xinhai Li ◽  
Zhixing Wang ◽  
Huajun Guo ◽  
Wenjie Peng ◽  
...  

Core-shell composite material LiNi[Formula: see text]Co[Formula: see text]Al[Formula: see text]O2/LiMn[Formula: see text]Ni[Formula: see text]Co[Formula: see text]O2 (NCA/NCM) was synthesized via a coprecipitation and spray pyrolysis process. The properties of pristine LiNi[Formula: see text]Co[Formula: see text]Al[Formula: see text]O2 (NCA) and Core-shell NCA/NCM were investigated by scanning electron microscopy, transmission electron microscopy, Galvanostatic cell cycling and electrochemical impedance spectroscopy. Results showed that the Core-shell NCA/NCM exhibited enhanced rate capability and cycling performance than the pristine NCA. The improved electrochemical performance is due to the fact that the NCM layer can stabilize the crystal structure of materials and suppress the deterioration of lithium ion diffusing ability during electrode process.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1766
Author(s):  
Meijie Zhu ◽  
Jiangang Li ◽  
Zhibei Liu ◽  
Li Wang ◽  
Yuqiong Kang ◽  
...  

The cathode material LiNi2/3Co1/6Mn1/6O2 with excellent electrochemical performance was prepared successfully by a rheological phase method. The materials obtained were characterized by X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscopy and charge-discharge tests. The results showed that both calcination temperatures and atmosphere are very important factors affecting the structure and electrochemical performance of LiNi2/3Co1/6Mn1/6O2 material. The sample calcinated at 800 °C under O2 atmosphere displayed well-crystallized particle morphology, a highly ordered layered structure with low defects, and excellent electrochemical performance. In the voltage range of 2.8–4.3 V, it delivered capacity of 188.9 mAh g−1 at 0.2 C and 130.4 mAh g−1 at 5 C, respectively. The capacity retention also reached 93.9% after 50 cycles at 0.5 C. All the results suggest that LiNi2/3Co1/6Mn1/6O2 is a promising cathode material for lithium-ion batteries.


2014 ◽  
Vol 2 (16) ◽  
pp. 5625-5630 ◽  
Author(s):  
Dongdong Li ◽  
Liang-Xin Ding ◽  
Suqing Wang ◽  
Dandan Cai ◽  
Haihui Wang

Ultrathin and highly-ordered 2D CoO nanosheet arrays exhibit superior electrochemical performance as an attractive anode material for LIBs.


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.


RSC Advances ◽  
2016 ◽  
Vol 6 (41) ◽  
pp. 34715-34723 ◽  
Author(s):  
Chao Li ◽  
Tongfei Shi ◽  
Decheng Li ◽  
Hideyuki Yoshitake ◽  
Hongyu Wang

Silicon is one of the most promising anode materials for lithium-ion batteries.


2013 ◽  
Vol 28 (5) ◽  
pp. 515-520 ◽  
Author(s):  
Zhen-Jun YU ◽  
Yan-Li WANG ◽  
Hong-Gui DENG ◽  
Liang ZHAN ◽  
Guang-Zhi YANG ◽  
...  

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