Application of PVP dispersant in lithium battery industry

Polyvinylpyrrolidone (PVP) is a non-ionic polymer polymerized by N-vinyl pyrrolidone (NVP) under certain conditions. PVP can be used as a dispersant for lithium-

ion battery electrodes and a processing aid for conductive materials. Data show that in the field of new energy batteries, the amount of 1GWh PVP is about 15

tons, mainly using industrial grade PVPK30. This paper describes in detail how PVP is used as a dispersant in lithium-ion battery and the market demand of PVP in

lithium-ion battery industry.

PVP dispersant for lithium battery cathode material

Slurry is very important in the production of lithium-ion batteries. The quality of the battery is 70% related to the quality of the pole sheet, and the quality of the

pole sheet is 70% related to the quality of the slurry. The production of slurry is equivalent to the completion of 50% of the battery, which is the core work of

battery manufacturing. Lithium ion battery slurry is basically composed of active material, conductive agent, binder and solvent. In the electrode preparation

section, material drying, sol and slurry three processes directly determine the quality of slurry.

Lithium ion battery cathode materials are difficult to disperse uniformly during the homogenization process, and dispersants need to be added. The cathode

materials of lithium batteries are mainly lithium cobaltate, lithium manganate, lithium iron phosphate, etc., because of its low conductivity, in the battery

preparation process, it is often necessary to add an appropriate amount of conductive agents, such as graphene, carbon nanotubes, etc., to improve the

conductivity of the cathode material.

However, due to the small particle size and large specific surface area of ultrafine battery cathode materials such as lithium iron phosphate, it is difficult to disperse

evenly during the homogenization process, resulting in high viscosity or low solid content of the slurry, which further leads to coating difficulties or even non-

coating, so the choice of dispersant is particularly important for the dispersion of lithium ion battery cathode slurry.

PVP is an ideal dispersant for lithium ion battery positive slurry. The PVP molecular structure contains strong polar lactam hydrophilic groups and CC long chain

oleophilic groups, which can be well compatible with a variety of solvents, and can be coated on the surface of the particles to form a good dispersion effect

through steric hindrance.

Adding appropriate amount of PVP to the positive battery slurry can significantly improve the dispersion of the slurry, make the slurry from Newtonian fluid to non-

Newtonian fluid, and stabilize the viscosity of the slurry at a low level, which is conducive to reducing the positive electrode impedance and improving the battery

performance.

PVP is used as a processing aid for lithium-ion battery auxiliary materials

Carbon nanotube conductive agent can improve the energy density of lithium-ion battery. A conductive paste is a paste formed by evenly dispersing the conductive

agent in the solvent, while a carbon nanotube conductive agent is a paste formed by dispersing the carbon nanotube as the conductive agent in the dispersion

solvent.

As a new type of conductive agent for lithium-ion batteries, carbon nanotube conductive agent can improve the conductivity of the battery, the addition amount is

reduced by 60%-70% compared with the conventional carbon black conductive agent, and at the same time, the amount of adhesive can be reduced, which can

significantly improve the energy density of lithium-ion batteries.

PVP can significantly improve the dispersion properties of carbon nanotubes in water, organic solvents and other substrates. Carbon nanotubes are lightweight,

perfectly connected in a hexagonal structure, and have many unusual mechanical, electrical, and chemical properties. Due to the strong van der Waals forces

between the tubes, carbon nanotubes form bundles or intertwine with each other, resulting in agglomeration, which severely limits their mechanical, thermal and

electrical applications.

PVP is a kind of amphiphilic polymer with special structure. The pyrrolidone group is a hydrophilic group, the main chain is a hydrophobic segment of C−C bond,

and it is lipophilic, so it can dissolve in water or alcohol, carboxyl and other organic solvents. Acids and amine alkanes. The introduction of amphiphilic polymer PVP

onto the surface of CNT can significantly improve the dispersion of CNT in water, organic solvents and other substrates.

The medium molecular weight PVPK25 and PVPK30 have the best dispersion effect on multi-walled carbon nanotubes, and the viscosity of the slurry is low. The

multi-walled carbon nanotubes have the characteristics of nearly Newtonian fluid, and the particles are evenly dispersed, the average particle size is small, and

they have good stability.

At the same time, its resistivity is also low, the adsorption capacity is higher than that of low molecular weight PVPK17 and high molecular weight PVPK90, and it

has better steric resistance modification effect on the multi-wall carbon nanotubes, making the multi-wall carbon nanotubes almost dispersed in a single root, and

the entanglement phenomenon is significantly reduced.

Demand analysis of PVP dispersant in lithium battery industry

1. The annual demand for PVP dispersants for carbon nanotube conductors is increasing rapidly

In 2025, the global demand for PVP dispersants for carbon nanotube conductors will reach 7,375 tons. According to the analysis, 12.5kgPVP needs to be added as

a dispersant per ton of carbon nanotube conductive agent, and if all PVP is used, the global demand for PVP dispersant for carbon nanotube conductive agent will

reach 1975 tons in 2022 and 7,375 tons in 2025.

2, the future lithium battery PVP annual demand is expected to reach 30,000 tons

Global shipments of lithium-ion batteries are growing rapidly. According to the data, the overall global shipment of lithium-ion batteries in 2021 was 562.4GWh, a

significant increase of 91% year-on-year. From a structural point of view, the global automotive power battery shipments were 371GWh, an increase of 134.7%;

Shipments of energy storage batteries were 66.3GWh, up 132.6% year on year; 3C small battery shipments were 125.1GWh, up 16.1% year-on-year. Related

enterprises can refer to lithium 100.

In 2025, the global annual demand for PVP for lithium batteries is expected to reach 33,100 tons. It is expected that in 2025, global power battery shipments will

reach 1550GWh, and energy storage battery shipments will reach 476GWh. Based on the high growth rate of the new consumer electronics market and the

improvement of the unit capacity of traditional 3C consumer electronics, assuming that the compound annual growth rate of global consumer lithium-ion battery

shipments is 10%, shipments will reach 183.2GWh in 2025. If you are interested in consumer batteries, here are relevant 3C consumer lithium battery

manufacturers for reference.

According to the above analysis, assuming that the amount of PVP in the lithium-ion battery field is about 15 tons of 1GWh, the annual demand for lithium-ion

battery PVP will reach 11,600 tons in 2022 and 33,100 tons in 2025.