Progress and challenges for replacing n-methyl-2-pyrrolidone / polyvinylidene fluoride slurry formulations in lithium-ion battery cathodes

Abstract

With electric vehicles, energy storage systems, and portable electronic devices becoming increasingly popular, the demand for lithium-ion batteries has surged considerably. In the lithium-ion battery industry, n-methyl-2-pyrrolidone (NMP) is widely used as the solvent for cathode slurry, and polyvinylidene fluoride (PVDF) is used as the cathode binder. However, because of the harmful effect of NMP on the environment and human health, the use of NMP and PVDF for lithium-ion batteries will be highly regulated in the future. Therefore, developing eco-friendly alternatives is crucial for formulating systems using new solvents and binders. Despite numerous efforts, these alternatives have not been widely adopted across the lithium-ion battery industry. It is due to their limited ability to compete on price or performance to replace the traditional NMP/PVDF slurry formulations. This review investigates developments in the search for new solvents and binders that can be used in cathode slurry compositions. The new systems can potentially decrease energy consumption and manufacturing costs associated with NMP recovery, energy-intensive drying processes, and material expenses. We discuss key factors and technical challenges from earlier studies and compare them with the current, optimized formulations based on NMP and PVDF.