Electrochemical Behavior of LiCo(1-x)MnxO2 Crystalline Powders

2014 ◽  
Vol 895 ◽  
pp. 334-337
Author(s):  
Azira Azahidi ◽  
Norlida Kamarulzaman ◽  
Kelimah Elong ◽  
Nurhanna Badar ◽  
Nurul Atikah Mohd Mokhtar

LiCoO2 is a well-known cathode material used in commercial Li-ion batteries but it has its own limitations in terms of cost and toxicity. Improvement of the material by partial substitution of Co with other transition metals is one of the alternative and effective ways to overcome the limitations and improve the electrochemical performance of cathode materials. The transition metal element used for the substitution has to be cheaper and non-toxic thus Mn is chosen here. LiCo(1-x)MnxO2 (x= 0.1, 0.2, 0.3) we synthesized by a novel route using a self-propagating combustion (SPC) method. The samples are analyzed using X-Ray Diffraction (XRD) for phase purity and Field Emission Scanning Electron Microscopy (FESEM) for morphology and particle size studies. The materials obtained are phase pure. In terms of electrochemical activity, though it does not show better first cycle discharge capacity, the Mn doped materials have improved capacity retention. Results showed that LiCo0.9Mn0.1O2 and LiCo0.8Mn0.2O2 exhibited less than 8 % capacity loss in the 20th cycle compared to 12 % for LiCoO2.

2012 ◽  
Vol 501 ◽  
pp. 133-137 ◽  
Author(s):  
Azira Azahidi ◽  
Kelimah Elong ◽  
Nurhanna Badar ◽  
Nurul Atikah Mohd Mokhtar ◽  
Rusdi Roshidah ◽  
...  

LiCoO2 has been used as a cathode material in commercial Li-ion batteries. This is due to advantageous properties of the LiCoO2 like ease of preparation and good electrochemical characteristics. However, the high cost and toxicity of Co has limited its use. Therefore, the substitution of Co in the LiCoO2 by non-toxic and inexpensive transition metallic element is needed. Mn is considered as one of the promising candidates to fulfill all the requirements. Partial substitution of Co by Mn has also been considered to enhance the stability of LiCoO2 lattice, minimize capacity fading and increase cycle life of the Li-ion battery. LiCo(1-x)MnxO2 (x= 0.1, 0.2, 0.3) were prepared by using a self-propagating combustion (SPC) method. X-ray diffraction (XRD) of the samples were carried out for phase analysis and showed that all the materials are pure. The samples were also analyzed using the Field Emission Scanning Electron Microscope (FESEM) to study its morphology and particle size. Finally cathodes were fabricated and assembled in an inert gas-filled fabrication box. Discharge profiles of the materials were carried out in the voltage range of 4.3 V – 3 V. The materials obtained were phase pure and improved the capacity fading of the materials compared to LiCoO2. All of the materials exhibited less than 10% capacity loss even though it does not improve the first cycle discharge capacity.


2011 ◽  
Vol 347-353 ◽  
pp. 3662-3665 ◽  
Author(s):  
Yu Hui Wang ◽  
Zhe Li ◽  
Kai Zhu ◽  
Gang Li ◽  
Ying Jin Wei ◽  
...  

The Li[Li0.2Co0.4Mn0.4]O2 cathode material was prepared by a sol-gel method. Combinative X-ray diffraction (XRD) studies showed that the material was a solid solution of LiCoO2 and Li2MnO3. The material showed a reversible discharge capacity of 155.0 mAhg−1 at -20 °C, which is smaller than that at room temperature (245.5 mAhg−1). However, the sample exhibited capacity retention of 96.3 % at -20 °C, only 74.2 % at 25 °C. The good electrochemical cycle performance at low temperature was due to the inexistence of Mn3+ in the material.


Author(s):  
Partha P. Paul ◽  
Chuntian Cao ◽  
Vivek Thampy ◽  
Hans-Georg Steinrück ◽  
Tanvir R. Tanim ◽  
...  

ChemSusChem ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2240-2250 ◽  
Author(s):  
Lea de Biasi ◽  
Alexander Schiele ◽  
Maria Roca‐Ayats ◽  
Grecia Garcia ◽  
Torsten Brezesinski ◽  
...  

2019 ◽  
Vol 11 (34) ◽  
pp. 30719-30727 ◽  
Author(s):  
Selvamani Vadivel ◽  
Nutthaphon Phattharasupakun ◽  
Juthaporn Wutthiprom ◽  
Salatan duangdangchote ◽  
Montree Sawangphruk

2010 ◽  
Vol 25 (8) ◽  
pp. 1601-1616 ◽  
Author(s):  
Jordi Cabana ◽  
Christopher S. Johnson ◽  
Xiao-Qing Yang ◽  
Kyung-Yoon Chung ◽  
Won-Sub Yoon ◽  
...  

The complexity of layered-spinel yLi2MnO3·(1 – y)Li1+xMn2–xO4 (Li:Mn = 1.2:1; 0 ≤ x ≤ 0.33; y ≥ 0.45) composites synthesized at different temperatures has been investigated by a combination of x-ray diffraction (XRD), x-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR). While the layered component does not change substantially between samples, an evolution of the spinel component from a high to a low lithium excess phase has been traced with temperature by comparing with data for pure Li1+xMn2–xO4. The changes that occur to the structure of the spinel component and to the average oxidation state of the manganese ions within the composite structure as lithium is electrochemically removed in a battery have been monitored using these techniques, in some cases in situ. Our 6Li NMR results constitute the first direct observation of lithium removal from Li2MnO3 and the formation of LiMnO2 upon lithium reinsertion.


1994 ◽  
Vol 344 ◽  
Author(s):  
P. H. Bolt ◽  
M. E. Van Ipenburg ◽  
J. W. Geus ◽  
F. H. P. M. Habraken

AbstractAn important cause of deactivation of alumina supported transition metal (oxide) catalysts is a solid state reaction between the active component and the support. We therefore studied the hightemperature behavior of Me layers (Me = Co, Ni, Cu and Fe) on polycrystalline α-A12O3 and γ- Al2O3 substrates. The samples were first oxidized at moderate temperatures and then annealed at high temperatures (up to 1000 °C) in O2, N2, or N2/O2 mixtures. The interfacial reaction to MeA12O4 was assessed using Rutherford Backscattering Spectrometry and X-ray diffraction. The reaction rate strongly depends on the transition metal element Me: Fe < Ni < Co < Cu. Low oxygen pressures favour spinel formation. γ-A12O3 shows a much higher reactivity towards the MeOx overlayers than α-Al2O3.


2011 ◽  
Vol 1333 ◽  
Author(s):  
Gene M. Nolis ◽  
Natalya A. Chernova ◽  
Shailesh Upreti ◽  
M. Stanley Whittingham

ABSTRACTLiFePO4 has shown considerable promise as a cathode material in Li-ion batteries due to its stability, low toxicity and high cyclability. However, the data on thermodynamic stability of olivine phase FePO4 (o-FePO4), the delithiated form of o-LiFePO4, remains scarce and contradictory. In this work, o-FePO4 was synthesized by chemical delithiation of o-LiFePO4 and characterized structurally and thermally. X-ray diffraction and absorption data indicate pure olivine phase, but with residual amount of Fe2+, most likely due to incomplete delithiation. Differential scanning calorimetry and thermal gravimetric analysis reveal that o-LixFePO4 decomposes exothermally above 550 °C with about 9% weight loss, the products being trigonal phase FePO4, Fe7(PO4)6, and LiPO3.


2013 ◽  
Vol 4 ◽  
pp. 665-670 ◽  
Author(s):  
Mario Marinaro ◽  
Santhana K Eswara Moorthy ◽  
Jörg Bernhard ◽  
Ludwig Jörissen ◽  
Margret Wohlfahrt-Mehrens ◽  
...  

Aprotic rechargeable Li–O2 batteries are currently receiving considerable interest because they can possibly offer significantly higher energy densities than conventional Li-ion batteries. The electrochemical behavior of Li–O2 batteries containing bis(trifluoromethane)sulfonimide lithium salt (LiTFSI)/tetraglyme electrolyte were investigated by galvanostatic cycling and electrochemical impedance spectroscopy measurements. Ex-situ X-ray diffraction and scanning electron microscopy were used to evaluate the formation/dissolution of Li2O2 particles at the cathode side during the operation of Li–O2 cells.


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