Anode binder

Anode binder is mainly used to provide bonding among active anode material, conductive agent and negative current collector. Binder could bond various components together to form an adhesive material, which is then bonded to the metal foil. Binder with excellent performance has good dispersion in slurry medium, which can evenly adhere active material to current collector. Binder also needs to have little influence on ion and electron transport, and have strong stability in electrode. In the existing graphite anode system, the commonly used adhesive is SBR+CMC hybrid system, and the performance parameters of commonly used SBR binder are given as follows:
 
1. Tg(°C): 15  
2. D50(nm): 130
3. Solid content (Wt%): 45
4. PH: 7.0-8.0
5. Electrolyte swelling (%): 150

Cathode dispersant

Cathode dispersant is an important component of cathode paste and conductive paste. If active cathode material and conductive agent dissolve unevenly or agglomerate in electrode paste, it will affect the coating performance of the electrode paste. Dispersant used for lithium-ion cathode slurry can be divided into the PVP type and the new type (polyethers, polyesters, etc.), among which the new type has better dispersion performance than the PVP type. Currently, the new type dispersant is mainly used in phosphate based cathode paste for lithium-ion battery, to improve the dispersion, fluidity, and uniformity.

Binder for carbon layer on aluminum foil

Before coating electrode slurry, the surface of current collector should be treated to improve the adhesion and anti-corrosion performance of the coating slurry, reduce the resistance between the active coating layer and the current collector, improve the adhesion between the active coating layer and the current collector, and ensure the anti-corrosion ability, mechanical properties and surface quality. Currently, the commonly used binder for carbon layer on aluminum foil in market are PVDF, SBR, CMC and PAA.

Separator adhesive material

Separator adhesive material refers to ceramic coating binder and polymer coating binder, ceramic separator is obtained by coating a mixture of inorganic particles and adhesive polymer on the surface of a porous substrate to obtain an inorganic/organic composite porous composite film. The binder plays a role in the bonding between particles and between particles and substrates; The polymer coating film mainly plays the role of enhancing the adhesion of cathode and anode, preventing the deformation of the battery during the cycle and improving the hardness of the cell. Currently, the commonly used adhesive for polymer coating is polyvinylidene fluoride (PVDF).
PVDF is a fluoropolymer with good mechanical strength, chemical stability, electrochemical stability, thermal stability and good affinity for electrolyte. The basic parameters are given as follows:
 
1. Melt flow index (450°C/21.6kg): 3-8g/10min
2. Melting temperature (°C): 148-155