Conductive Additives for Improving the Rate Capability of Cathode Materials in Secondary Lithium Batteries

Abstract

Conductive additive, one of the most important components of a battery, is an indispensable key material in the high-current charging and discharging processes of lithium-ion batteries. The most fundamental reason for adding appropriate conductive additives in the electrode is to improve the poor conductive performance of the electrode-active material, reduce the internal resistance and polarization of the electrode, and improve the comprehensive performance of the battery. Herein, a graphene-like material with a unique two-dimensional morphology was proposed, as obtained by an efficient one-step electrochemical synthesis, which can provide a flexible plane-to-point conducting network to improve the electronic conductivity of cathode materials. Compared with the commercial conductive additive Super P, the NCM811 cathode material with ECGO can deliver a capacity of 147.3 mAh g–1 at a high rate of 2 C, and sulfur cathode retains 620 mAh g–1 after 200 cycles, corresponding to the capacity retention of 74%. Also, due to the presence of oxygen groups, ECGO is proposed as an effective conductive additive in Li-ion cathodes prepared by water-based processing. Therefore, the cathode materials with the ECGO conductive additive can contribute to reduce the interfacial resistance and increase the capability, showing great advantages compared to the commercial conductive additives.