Improvement of electrochemical performance of LiMn2O4 composite cathode by ox-MWCNT addition for Li-ion battery

Journal of the Brazilian Chemical Society

Su-qin Liu¹  Jian-feng Zhang¹  Ke-long Huang¹  Jin-gang Yu¹ 

[1] ,Central South University College of Chemistry & Chemical Engineering ,P. R. China

关键词: oxidized multi-walled carbon nanotubes;    composite electrode;    conducting network;    lithium ion batteries;   

DOI  :  10.1590/S0103-50532008000600005

来源: SciELO

【 摘 要 】

Oxidized multi-walled carbon nanotubes (ox-MWCNT) were used as conducting addition to prepare a novel network composite cathode for lithium ion battery. The morphology was analyzed by scanning electron microscope, LiMn2O4 active particles were connected by ox-MWCNT with the formation of three-dimensional networking wiring. Electron transport and electrochemical activity were improved effectively. Galvanostatic charge-discharge tests of LiMn2O4/ox-MWCNT cathode showed that the initial discharge capacities are 119.4, 110.6, 105.5 and 91.4 mAh g-1 at the rate of 0.1, 0.5, 1 and 2 C, respectively, which were much higher than LiMn2O4/acetylene black (AB) at the same content. The electrochemical AC impedance spectroscopy showed that the charge transfer resistance (Rct) of the composite electrode reduced obviously contrasting to 34.32 Ω for LiMn2O4/ox-MWCNT and 53.2 Ω for LiMn2O4/AB. Overall, it is found that a conductive network to facilitate electron transfer and good connection of the active-material particle to the network were playing an important role to rate capability and cycle efficiency.

【 授权许可】

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