25th International Symposium on Analytical and Environmental Problems
121
HYDROTHERMAL SYNTHESIS OF THE MIXED-PHASES BASED ON Mn FOR LITHIUM ION BATTERY APPLICATION
Dabici Anamaria1, Ursu Daniel1, Vajda Melinda1, Miclau Marinela1*, Casut Cristian1, Albulescu Daiana1
1National Institute for Research and Development in Electrochemistry and Condensed Matter, 1 Plautius Andronescu Street, 300224 Timisoara, Romania
e-mail: marinela.miclau@gmail.com Abstract
Over the past few years, Li-ion batteries (LIBs) have been widely applied in mobile devices, electronic vehicles (EVs) and energy storage systems in our daily life [1,2]. The cathode material is a critical part in LIBs which determines the electrochemical properties.
Among this family, Mn-based layered cathode materials, considered as one of the most promising candidates in next-generation rechargeable batteries, have been attracting significant attention due to their extraordinarily high specific capacity of 280 mA h g-1, potential in improving the working voltage to 4.8 V and relatively high Li-ion diffusivity compared with LiFePO4 and LiMn2O4. Materials such as: Li1.2Ni0.13Co0.13Mn0.54O2 and Li1.2Mn0.56Ni0.16Co0.08O2 have been investigated intensively, however, the progress of the commercialization has been slow due to voltage fade, insufficient rate capability and structural degradation during long-time cycling, which are considered as the bottlenecks for further promotion [5].
According to the literature reports, the layered Li2MnO3 belongs to the C2/m symmetry where Li and Mn ions occupy the octahedral interstices of a cubic close-packed oxygen lattice [6]. Forming composite phase of Li2MnO3 with other polymorphs of lithium metal oxides is also of great interest. For example, Li2MnO3–LiMO2 M = Mn, Co, Ni, Cr, etc.
etc. composite electrode materials were reported where the Li2MnO3 in the composite can stabilize the monoclinic structure of LiMO2 upon cycling [7].
In this paper, we report the successful hydrothermal synthesis of LiMnO2/Li2MnO3
obtained from hydrothermal method at 250 °C for 48 hours using 10mL H2O and Na2S208 as oxidant. The structure of products was determined by powder X-ray diffraction (XRD) PW 3040/60 X’Pert PRO using Cu-Kα radiation with (λ=1.5418Å), in the range 2θ = 10-80°, at room temperature (figure 1a). A Scanning Electron Microscope InspectS (SEM) was used to observe the morphology of synthesized nanocrystals (figure 1b). The diffuse reflectance spectra (DSR) was obtained using a Lambda 950 UV-Vis-NIR Spectrophotometer with 150 mm integrating sphere in the wavelength range of 300–800 nm.
Figure 1. a) X-ray diffraction patterns and b) SEM images of LiMnO2/Li2MnO3 obtained from hydrothermal method at 250 °C for 48 hours.
25th International Symposium on Analytical and Environmental Problems
122 Acknowledgements
This paper is supported by the Romanian Government under the project PN 19 22 01 03.
References
[1] B. Dunn and J. M. Tarascon, Science, 2011, 334, 928–935.
[2] B. Luo, B. Wang, X. Li, Y. Jia, M. Liang and L. Zhi, Adv. Mater., 2012, 24, 3538–3543.
[3] M. M. Thackeray, C. S. Johnson, J. T. Vaughey, N. Li and S. A. Hackney, J. Mater.
Chem., 2005, 15, 2257–2267.
[4] J. B. Goodenough and Y. Kim, Chem. Mater., 2010, 22, 587– 603.
[5] B. Xu, C. R. Fell, M. Chi and Y. S. Meng, Energy Environ. Sci., 2011, 4, 2223.
[6] P. J. Phillips, J. Bareno, Y. Li, D. P. Abraham and R. F. Klie, ˜ Adv. Energy Mater., 2015, 5, 1501252.
[7] M. M. Thackeray, C. S. Johnson, J. T. Vaughey, N. Li, and S. A. Hackney, J. Mater.
Chem., 2005, 15, 2257
