Hybrid Point-to-Line Conductive Network of Carbon Nanotubes and Denka Black for High-Rate Lithium-Ion Battery Cathodes

In this study, a composite dispersion of conductive additives, comprising carbon nanotubes (CNT) and Denka Black (DB), was prepared via a high-pressure homogenization (HPH) process. This approach was designed to overcome the limitations of carbon black-based conductive networks in lithium-ion battery cathodes. Raman mapping confirmed the uniform dispersion of the CNT+DB mixture, while scanning electron microscopy revealed that the composite additive formed a more continuous point-to-line conductive network compared to individual CNT or DB electrodes. Electrical conductivity measurements and electrochemical impedance spectroscopy revealed higher electronic conductivity and lower charge-transfer resistance of the CNT+DB than the individual additives. During cyclic voltammetry, the CNT+DB electrode exhibited the highest peak current among the samples, suggesting more active redox behavior. Electrochemical performance tests demonstrated that the CNT+DB electrode retained 55.7% of its initial capacity at 5C and maintained 71.9% of its capacity during long-term cycling at 2C, exhibiting enhanced high-rate stability. These findings indicate that the three-dimensional conductive network created by combining CNT and DB effectively enhances electron pathways and stabilizes ion transport within the electrode.