The Role of N-methylpyrrolidone in The Production of Lithium Ion Batteries

Lithium-ion batteries are now internationally recognised as an ideal chemical energy source, with small size, large capacity, high voltage and other advantages, they are widely used in mobile phones, laptops and other electronic products, and the expanding field of electric vehicles will give lithium-ion batteries more room for development in the future.

China and the world's major developed countries have introduced many policies to support new energy vehicles. New energy vehicles and other seven strategic emerging industries development plan, will be from the policy level of China's electric vehicles to further promote. 2009 global production of lithium-ion batteries is about 3.05 billion, the total battery capacity of about 15,000WMH, the data show that: 2013 lithium batteries for electric vehicles reached 14,000WMH, equivalent to 93% of the global capacity of lithium batteries in 2009 small. In 2018, the capacity of lithium batteries for electric vehicles reached 45,000WMH, equivalent to nearly three times the capacity of small lithium batteries in 2009.

NMP belongs to nitrogen heterocyclic compounds, with a series of excellent physical and chemical properties, it is an efficient selective solvent with non-toxicity, high boiling point, high polarity, low viscosity, low corrosiveness, high solubility, low volatility, good stability and easy to recover. It is widely used in petrochemicals, pesticides, pharmaceuticals, electronic materials and other fields.

NMP(N-Methyl-2-pyrrolidone) is a very important auxiliary material for the production of lithium-ion battery electrodes, the most commonly used solvent in the lithium-ion battery front-end dosing process, commonly known as methyl, the scientific name is N-methyl pyrrolidone, molecular formula C5H9NO.

At the batching stage: as a PVDF solvent, it participates in the dispersion of the slurry, forming a medium that is homogeneous and remains stable for a long time within a certain viscosity range.

In the coating stage: as the main liquid carrier of slurry, it is uniformly coated on the metal substrate with stable thickness, which requires very good wettability and fluidity with the metal substrate. In the coating and baking stage: the wet film runs at a uniform speed in the oven, the solvent volatilises regularly, NMP assumes the function of pore making, NMP volatilises from the wet film at a stable speed, forming a porous microelectrode structure with uniform pore size and distribution.

Coating machine NMP exhaust gas recovery and treatment system and waste heat back to the device through the recovery of NMP exhaust gas, air purification and treatment to achieve "zero" emission requirements, waste heat recycling can be achieved according to customer requirements to save thermal energy efficiency of 65-80%, investment is small, low energy consumption, low power, is imported about 10% of the machine, do not have to rotate the wheel can be achieved and exceeded the Japanese NICHIAS hydrophobic zeolite ketone adsorption of honeycomb rotor of the performance indicators, is a cost-effective products!

The working principle is as follows: NMP exhaust gas recovery and treatment system can be designed as 50-100% fully closed cycle, solvent recovery - the use of freezing - internal circulation adsorption and concentration technology to recover organic solvents in the exhaust gas, the recovery rate of organic solvents is greater than 85-95%. Due to the coating machine exhaust air volume, low concentration, the use of internal circulation will be constantly in the exhaust gas of organic solvents concentrated to a certain concentration, and then condensation recovery, reduce the cost of recovery. At the same time, the product has the following advantages.