Electrochemical Properties of Li-Riched Li[Li0.2Co0.4Mn 0.4]O2 Cathode Material for Lithium Ion Batteries

2011 ◽  
Vol 347-353 ◽  
pp. 3658-3661
Author(s):  
Zhe Li ◽  
Kai Zhu ◽  
Yu Hui Wang ◽  
Gang Li ◽  
Gang Chen ◽  
...  

The Li[Li0.2Co0.4Mn0.4]O2 cathode material was prepared by a sol-gel method. The X-ray diffraction (XRD) spectroscopic showed that the material was a solid solution of LiCoO2 and Li2MnO3. The material showed a reversible discharge capacity of 155.6 mAhg−1 in the voltage window of 2.0-4.3 V after percharge to 4.6 V. While the material cycled in the same voltage window without precharge could only deliver capacity of 77.6 mAhg−1. This high capacity was attributed to the loss of oxygen and structural rearrangement in the precharge process.

2019 ◽  
Vol 92 (7) ◽  
pp. 1013-1019 ◽  
Author(s):  
P. A. Novikov ◽  
A. E. Kim ◽  
K. A. Pushnitsa ◽  
Wang Quingsheng ◽  
M. Yu. Maksimov ◽  
...  

2014 ◽  
Vol 636 ◽  
pp. 49-53
Author(s):  
Si Qi Wen ◽  
Liang Chao Gao ◽  
Jia Li Wang ◽  
Lei Zhang ◽  
Zhi Cheng Yang ◽  
...  

To improve the cycle performance of spinel LiMn2O4as the cathode of 4 V class lithium ion batteries, spinel were successfully prepared using the sol-gel method. The dependence of the physicochemical properties of the spinel LiCrxMn2-xO4(x=0,0.05,0.1,0.2,0.3,0.4) powders powder has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge test and electrochemical impedance spectroscopy (EIS). The results show that as Mn is replaced by Cr, the initial capacity decreases, but the cycling performance improves due to stabilization of spinel structure. Of all, the LiCr0.2Mn1.8O4has best electrochemical performance, 107.6 mAhg-1discharge capacity, 96.1% of the retention after 50 cycles.


2011 ◽  
Vol 04 (01) ◽  
pp. 61-64 ◽  
Author(s):  
ZHAOHUI LI ◽  
JIAOJUN TANG ◽  
JIE YANG ◽  
CHENG CHENG ◽  
QIZHEN XIAO ◽  
...  

A porous vanadium pentoxide ( V2O5 ) material was prepared through a facile sol-gel route using β-cyclodextrin (β-CD) as template reagent. Its crystal structure and morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively. The electrochemical properties of the as-prepared V2O5 in 1.0 mol l-1 Li2SO4 aqueous electrolyte were investigated by galvanostatic charging/discharging and cyclic voltammetry. The results revealed that the porous V2O5 could deliver the average capacities of 67, 54 and 42 mAh g-1 at the rates of 0.1, 0.5 and 2 C, respectively. The cycling performances of the V2O5/LiMn2O4 cells suggested that the porous V2O5 material could be used as an anode material for aqueous rechargeable lithium-ion batteries.


2021 ◽  
Author(s):  
K. Kalaiselvi ◽  
S. Premlatha ◽  
M. Raju ◽  
Paruthimal Kalaignan Guruvaiah

Abstract LiNi1/3Mn1/3Co1/3O2 as a promising cathode material for lithium-ion batteries was synthesized by a sol-gel method using nitrate precursor calcined at 800°C for 10 hours. The crystallite nature of samples is confirmed from X-ray diffraction analysis. SEM and TEM analyses were used to investigate the surface morphology of the prepared samples. It was found that, highly crystalline polyhedral RuO2 nanoparticles are well doped on the surface of pristine LiNi1/3Mn1/3Co1/3O2 with a size of about approximately 200 nm. The chemical composition of the prepared samples was characterized by EDX and XPS analyses. The electrochemical performance of the proposed material was studied by cyclic voltammetry and charge/discharge analyses. The electrode kinetics of the samples was studied by electrochemical impedance spectroscopy. The developed RuO2 doping may provide an effective strategy to design and synthesize the advanced electrode materials for lithium ion batteries. The doping strategy has dramatically increased the capacity retention from 74 % to 90% with a high discharge capacity of 251.2 mAhg− 1. 3 % RuO2-doped LiNi1/3Mn1/3Co1/3O2 cathode materials have showed the similar characteristics of two potential plateaus obtained at 2.8 and 4.2 V compared with un doped electrode cathode material. These results revealed the enhanced performance of RuO2- doped LiNi1/3Mn1/3Co1/3O2 during insertion and extraction of lithium ions compared to pristine material.


2020 ◽  
Vol 12 (10) ◽  
pp. 1581-1585
Author(s):  
Tae-Hyun Ha ◽  
Jun-Seok Park ◽  
Gyu-Bong Cho ◽  
Hyo-Jun Ahn ◽  
Ki-Won Kim ◽  
...  

LiNixCoyAlzO2 (NCA) is one of the most promising candidates of cathode material for lithium ion batteries because of its high capacity, energy density, and low cost. However, Ni-rich NCA cathode materials suffer from side reaction (formation of lithium carbonate and hydrogen fluoride attack) between electrolyte and surface of electrode and irreversible phase transition leading to capacity fading and thermal instability. These problems could be improved by coating and doping of transition metal elements. Si doping contributes to stabilization of the unstable R-3m structure, and Ti coating is capable of prohibiting the direct physical contact of electrode with electrolyte. In this work, LiNi0.8Co0.15Al0.05O2 (NCA) cathode materials coated or/and doped by Ti and Si elements were fabricated by co-precipitation method using the ball-milling. The crystal structure, morphology and electrochemical properties are investigated using X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), transmission electron microscopy (FE-TEM), and WBCS3000 (WonA tech Co., Ltd.). The EIS and charge/discharge results of Si doped and Ti coated NCA exhibited the lowest resistance value (147.19 Ω) and capacity retentions of 88% after 100 cycles at 0.5 C.


2014 ◽  
Vol 07 (02) ◽  
pp. 1450016 ◽  
Author(s):  
Chenglin Hu ◽  
Yuping Wu ◽  
Yongnian Dai

Non-stoichiometric LiFe 1-x PO 4/ C composites were synthesized by a simple sol–gel method. Different impurities were detected in the X-ray diffraction measurements with the change of Fe content. The effects of Fe -poor on the structure and electrochemical performance of LiFePO 4 were investigated. Compared with stoichiometric LiFePO 4/ C , non-stoichiometric samples show better electrochemical performance because they have smaller impedance and faster lithium ion diffusion. Among these non-stoichiometric samples, LiFe 0.94 PO 4/ C cathode delivers the highest capacity of 149 mAh g-1 at 0.2 C and 103 mAh g-1 at 5 C and no capacity loss was found after 100 full cycles.


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