Papers by Keyword: Conductive Agent

Abstract: The potential use of multi-walled carbon nanotubes (MWCNTs) produced by chemical vapour deposition (CVD) as a conductive agent for electrodes in Li-ion batteries has been investigated. LiNi0.33Co0.33Mn0.33O2 (NCM) has been chosen as active material for positive electrodes, and a nano-sized TiO2-rutile for the negative electrodes. The electrochemical performances of the electrodes were studied by galvanostatic techniques and especially the influence of the nanotubes on the rate capability and cycling stability has been evaluated. The addition of MWCNTs significantly enhanced the rate performances of both positive and negative electrodes and improved the capacity retention upon cycling. The obtained results demonstrated that the addition of MWCNTs in low amounts to the electrode composition enables an increase in both energy and power density of a Li-ion battery.

Abstract: CoO was usually added to the positive electrodes of MH/Ni batteries as the conductive agent. In this paper, well crystallized multi-walled carbon nanotubes (CNTs) with diameter about 10 nm were added to the positive electrodes of MH/Ni batteries together with CoO. During the process of transformation from CoO to CoOOH, a complex conductive network was created with CNTs as the frame. Because of the high conductivity and the excellent tension characteristics of CNTs, the charge-transfer capability of the electrode was improved and the integrality of the complex conductive network was enhanced. The electrochemical measurements indicated that the impedance of the electrode with CNT-CoO complex conductive agent was lessened compared to the electrode with simple CoO agent. Performance tests of the sealed batteries showed that the positive electrodes with CNT-CoO complex conductive agent exhibited higher discharge voltage, improved capacity, modified discharge stability and prolonged lifespan, especially at high current rates.