Influence on bond strength: By controlling the structure and molecular weight of the polymer, the ductility and strength of the binder inside the lithium battery can be controlled.
By modifying the surface functional groups of binder particles, the distribution position of binder in the active substance can be affected. In the face of different active substances, the distribution can affect and improve the bond strength.
Effect on migration inhibition: added in the slurry and coated on the pole sheet, in order to improve production efficiency, the drying temperature is generally increased to meet the production, when the temperature is high, the evaporation rate of water is faster, so the suspended binder will quickly migrate to the surface of the sheet, resulting in the loss of Cu interface binder, especially in the roller press caused by sticky roll or depowder, drop and other phenomena.
Effect on internal resistance: After the binder particles are dried in the electrode, they will absorb electrolyte swelling in the battery, and excessive swelling will affect the e-electron transfer, resulting in the rise of internal resistance. By controlling the affinity between polymer and electrolyte, the internal resistance can be prevented to some extent.
Effect on battery expansion: the monomer composition on the surface of the binder particles is controlled, and the surface is modified, so as to achieve excellent adhesion between the active substance and the metal, anti-electrolyte chemical stability, and the stability of the colloid in the slurry. Coupled with the control of the ductility and strength of the binder itself, the purpose of inhibiting electrode expansion can be achieved.
Influence on cycle performance: the resistance of the binder particles to the electrolyte is improved, the strength and elasticity are reduced with time, and the bonding force can be guaranteed for a long time. Especially in the case of long-term circulation, it is more and more able to reflect the test of elasticity and durability of the binder.
X-ray irradiator X-ray orientation analyzer Nondestructure testing equipment NDT