Effects of conducting carbon on the electrochemical performance of LiCoO 2 and LiMn 2O 4 cathodes

Abstract

The effects of conducting carbon additive on the performance of LiCoO 2 and LiMn 2O 4 cathodes in lithium-ion batteries have been investigated. While 2–5 wt.% of carbon are adequate for the LiMn 2O 4 cathode to deliver good rate capability and maintain cyclability, the LiCoO 2 cathode requires more carbon (10 wt.%) to achieve likewise. The sensitivity of the LiCoO 2 electrode for carbon content is particularly pronounced in high rate charging. Cyclic voltammetry and electrochemical impedance spectroscopy measurements indicate that deteriorating particle contacts leading to the incomplete charging of the active materials is the primary cause of material non-performance.