What exactly is NMP N-methylpyrrolidone

NMP is one of the most commonly used accessories for lithium batteries. NMP is the solvent of PVDF binder, is the English abbreviation of N-methylpyrrolidone, a colorless transparent liquid, with low toxicity, high boiling point, strong polarity, low viscosity, strong solubility, chemical stability, excellent thermal stability and other characteristics, can be miscible with water, PVDF, positive and negative electrode materials, etc., widely used in the preparation of lithium batteries. When making electrode sheets, NMP is used as a solvent to fuse various materials required for electrodes, such as binder, positive active substance, conductive agent, etc., so that the binder is fully in contact with other substances and evenly distributed. As a solvent, the quality of NMP directly affects the quality of pulping coating of lithium-ion batteries, which is an indispensable solvent material. From the perspective of the distribution of NMP application fields, it is mainly used in the preparation of lithium batteries, accounting for 74%.

NMP is a very important auxiliary material for the production of lithium-ion battery electrodes, and is the most commonly used solvent in the batching process of lithium-ion batteries. NMP is used to dissolve the positive binder PVDF, and as the diffusion liquid of carbon nanotube conductive slurry (CNT) for lithium batteries, respectively affecting the coating quality/effect, improve the energy density of lithium batteries, with high boiling point, outstanding solubility, low volatility, strong selectivity, good thermal stability, strong moisture absorption and other characteristics. Generally, NMP accounts for 3%-6% of the manufacturing cost of lithium batteries.
Solvent NMP, binder, active substance, conductive agent, etc., are mixed in proportion and sequence to make slurry, and the slurry is evenly coated on both sides of the aluminum foil by a coating machine, and then entered the dryer for sealed negative pressure air extraction drying. The exhaust gas (the main component is NMP) in the dryer is collected by the spray tower or molecular sieve and other equipment and is recovered by condensation. The condensed NMP recovery liquid is purified by professional distillation and purification equipment. After the product meets the requirements of the lithium battery production process, it can be recycled again.