Dispersion-assisted carbon nanotubes as a conductive agent for dry-processed cathode for lithium-ion battery

Developing a dry (solvent-free) manufacturing process for battery electrodes has garnered significant attention due to the need to reduce energy and solvent consumption while increasing electrode density. Among various methods, the PTFE fibrillation dry process stands out for its ability to lower production costs and simplify manufacturing, by creating a PTFE binder network without solvents. When combined with carbon nanotubes (CNTs) as exceptional conductive agents, this process offers great potential for fabricating electrodes with higher mass loadings. However, the poor dispersion of CNTs, particularly under solvent-free conditions, limits the widespread application of CNT-based dry-processed cathodes. In this study, we introduce an innovative step to the PTFE fibrillation dry process by utilizing polyvinylpyrrolidone (PVP) and a small amount of ethanol to enhance the dispersity of multi-walled CNT (MWCNT) within the dry electrode matrix, thereby improving the distribution of electrode components. By optimizing and comparing our PVP-multi-walled CNT dry-processed electrodes (PCDPEs) with multi-walled CNT-only dry-processed electrodes (CDPEs), we demonstrate that PCDPEs achieve superior electrochemical performance, with an initial discharge capacity of 211.47 mAh g⁻¹ at 0.2C, attributed to improved electron and charge transfer resulting from more uniform MWCNT distribution. Notably, PCDPEs with high mass loadings (up to 50 mg cm⁻²) deliver over 10 mAh cm⁻² with improved cycling stability. This approach significantly enhances the compatibility of MWCNT conductive agents with the PTFE fibrillation dry process, enabling the fabrication of high-performance cathodes without the use of toxic solvents.