LiFe1-xMnxPO4/C COMPOSITE AS CATHODE MATERIAL FOR LITHIUM ION BATTERY

2011 ◽  
Vol 04 (04) ◽  
pp. 319-322 ◽  
Author(s):  
AI FANG LIU ◽  
ZU BIAO WEN ◽  
YA FEI LIU ◽  
ZHONG HUA HU

LiFe 1-x Mn x PO 4/ C composites were prepared as cathode material for lithium ion battery via solid-state reaction and using glucose as reducing agent and carbon source. The crystal structure and morphology were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The resultant samples were pure olivine compounds with an orthorhombic structure. Their electrochemical performance was studied by galvanostatic charge–discharge test and cyclic voltammetry. The results showed that the sample LiFe0.8Mn0.2PO4/C with an average particle size of 400 nm exhibited the largest discharge capacity of 150 mAh g-1, excellent reversibility of charge–discharge and high capacity retention of 97% after a 50-cycle CV scanning. The improved electrical conductivity corresponding to the fine carbon layer around the LiFe0.8Mn0.2PO4 individual particle can be responsible for all these excellent electrochemical performance.

2015 ◽  
Vol 3 (1) ◽  
pp. 404-411 ◽  
Author(s):  
Xuan-Wen Gao ◽  
Yuan-Fu Deng ◽  
David Wexler ◽  
Guo-Hua Chen ◽  
Shu-Lei Chou ◽  
...  

Conductive polypyrrole (PPy)-coated LiNi0.5Mn1.5O4(LNMO) composites are applied as cathode materials in Li-ion batteries, and their electrochemical properties are explored at both room and elevated temperature.


2018 ◽  
Vol 11 (04) ◽  
pp. 1850068 ◽  
Author(s):  
Changlei Niu

Aluminium has shown its superiority in stabilization of the monoclinic VO2(B) in free-standing nanobelts. In this paper, aluminium-doped VO2(B) nanobelts are successfully fabricated by a facile one-step hydrothermal method and used as cathode for lithium-ion battery. XPS results show that Al-doping promotes the formation of high valence state of vanadium in VO2(B) nanobelts. Due to the accommodation of valence state of vanadium and lattice volume, Al-doped VO2(B) nanobelts used as the cathode material for lithium-ion batteries exhibit better lithium storage properties with high capacity of 172[Formula: see text]mAh[Formula: see text]g[Formula: see text] and cycling stability than undoped VO2(B) nanobelts. This work demonstrates that the doping of aluminium can significantly enhance the electrochemical performance of VO2(B), suggesting that appropriate cationic doping is an efficient path to improve the electrochemical performance of electrode materials.


2007 ◽  
Vol 280-283 ◽  
pp. 671-676 ◽  
Author(s):  
Hong Wei Chan ◽  
Jenq Gong Duh ◽  
Shyang Roeng Sheen

Surface modification on the electrode has a vital impact on lithium-ion batteries, and it is essential to probe the mechanism of the modified film on the surface of the electrode. In this study, a Li2O-2B2O3 film was coated on the surface of the cathode material by solution method. The cathode powders derived from co-precipitation method were calcined with various weight percent of the surface modified glass to form fine powder of single spinel phase with different particle size, size distribution and morphology. The thermogravimetry/differential thermal analysis was used to evaluate the appropriate heat treatment temperature. The structure was confirmed by the X-ray diffractometer along with the composition measured by the electron probe microanalyzer. From the field emission scanning electron microscope image and Laser Scattering measurements, the average particle size was in the range of 7-8µm. The electrochemical behavior of the cathode powder was examined by using two-electrode test cells consisted of a cathode, metallic lithium anode, and an electrolyte of 1M LiPF6. Cyclic charge/discharge testing of the coin cells, fabricated by both coated and un-coated cathode material, provided high discharge capacity. Furthermore, the coated cathode powder showed better cyclability than the un-coated one after the cyclic test. The introduction of the glass-coated cathode material revealed high discharge capacity and appreciably decreased the decay rate after cyclic test.


Author(s):  
Zhangxian Chen ◽  
Qiuge Zhang ◽  
Weijian Tang ◽  
Zhaoguo Wu ◽  
Juxuan Ding ◽  
...  

Nickel-rich LiNiCoMnO (LNCM811) is a promising lithium-ion battery cathode material, whereas the surface-sensitive issues (i.e., side reaction and oxygen loss) occurring on LNCM811 particles significantly degrade their electrochemical capacity retentions. A uniform LiZrO coating layer can effectively mitigate the problem by preventing these issues. Instead of the normally used weak hydrogen-bonding interaction, we present a covalent interfacial engineering for the uniform LiZrO coating on LiNiCoMnO materials. Results indicate that the strong covalent interactions between citric acid and NiCoMn(OH) precursor effectively promote the adsorption of ZrO coating species on NiCoMn(OH) precursor, which is eventually converted to uniform LiZrO coating layers of about 7 nm after thermal annealing. The uniform LiZrO coating endows LNCM811 cathode materials with an exceptionally high capacity retention of 98.7% after 300 cycles at 1 C. This work shows the great potential of covalent interfacial engineering for improving the electrochemical cycling capability of Ni-rich lithium-ion battery cathode materials.


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