Synthesis and Electrochemical Characteristics of LiMnPO₄/C Composite Materials for Lithium Ion Batteries

Abstract

Olivine-structured LiMnPO4 has attracted broad attention as a potential cathode material of Li-ion battery for EV application [1-2], which has some advantage with a higher energy density, higher redox potential and lower cost, etc. However, this material showed a poor electrochemical performance due to the low electronic conductivity [3-4]. Therefore, many researches have been performed to improve the electrochemical properties of LiMnPO4 material by the particle size reduction, cation doping and carbon coating, etc. [5-6]. In here, we studied nano-sized LiMnPO4/C composite materials with a high crystallization prepared using a modified co-precipitation method including a grinding mill and heat treatment process. As a result, the cell showed a good discharge capacity of 145mAh/g and a discharge potential of 3.8V. Furthermore, as the LiMnPO4/C material was combined with Li2MnO3-based material, the LiMnPO4/C composite materials showed a better electrochemical characteristic of above 200mAh/g at 0.05C. In summary, the nano-sized LiMnO4 material with a high crystallization shows good electrochemical properties at room temperature. References [1] J.N. Reimers, J.R. Dahn, J. Electrochem. Soc. 139 (1992) 209. [2] D.K. Kim, P. Muralidharan, H.-W. Lee, R. Ruffo, Y. Yang, C.K. Chan, H. Peng, R.A. Huggins, Y. Cui, Nano Letter 8 (11) (2008) 3948–3952. [3] N.N. Bramnik, H. Ehrenberg, Journal of Alloys and Compounds 464 (2008) 259–264.4) [4] J. Yang, J.J, Journal of The Electrochemical Society 153 (4) (2006) A716–A723 [5] T. Drezen, N.-H. Kwon, P. Bowen, I. Teerlinck, M. Isono, I. Exnar, Journal of Power Sources 174 (2007) 949–953. [6] A.V. Murugan, T. Muraliganth, A. Manthiram, Journal of The Electrochemical Society 156 (2) (2009) A79–A83