Synthesis and electrochemical performance of Li₂FeSiO₄/C/carbon nanosphere composite cathode materials for lithium ion batteries

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• 作者：Jinlong Yang ; Xiaochun Kang ; Lin Hu ; Xue Gong ; Daping He ; Tao Peng ; Shichun Mu ; ^{msc@whut.edu.cn}
• 关键词：Lithium ion battery ; Li-ion diffusion ; Li2FeSiO4 ; Carbon nanosphere ; Cathode materials
• 刊名：Journal of Alloys and Compounds
• 出版年：2013
• 出版时间：25 September, 2013
• 年：2013
• 卷：572
• 期：Complete
• 页码：158-162
• 全文大小：931 K

文摘

Li₂FeSiO₄/C/carbon nanosphere (CNS) composites as cathode materials for lithium-ion batteries were synthesized by a simple hydro-chemical method. The double-carbon structural design of glucose pyrolysis-carbon (C) and CNS improved electrochemical performance of the composite where the CNS can build conductivity belts to connect the Li₂FeSiO₄/C particles and to favor electronic transmission. The exchange current density and the diffusion coefficient of lithium ions with the composite were 0.208 mA cm^?2 and 1.06E?11 cm² S^?1, respectively, which were much larger than that of conventional Li₂FeSiO₄/C composite cathode materials (i = 0.131 mA cm^?2, D_Li = 4.69E?12 cm² S^?1). The electrochemical test results showed that the discharge capacity of 164.7 mA h g^?1 could be obtained, and especially, after 60 cycles, 98.4 % of the initial discharge capacity remained at 0.1 C of galvanostatic discharge in the potential range of 1.5-4.8 V (vs. Li/Li⁺). In addition, the discharge capacity of 92.4 mA h g^?1 at 5 C was easily recovered to 159.8 mA h g^?1 at 0.1 C.