Conductive Carbon Black for lithium ion batteries

Under scanning electron microscope, carbon black is chain or grape-like, and individual carbon black particles have very large specific surface area, carbon black has better ionic and electronic conductivity than graphite. The high specific surface area and tight packing of carbon black particles are conducive to the close contact between particles, forming a conductive network in the electrode, which is conducive to the adsorption of electrolytes and the improvement of ionic conductivity.

The carbon primary particles form branch chain structure, which can form chain conductive structure with the active material, which is helpful to improve the electronic conductivity of the material. However, the larger specific surface area of the process is difficult to disperse, with strong oil absorption. Therefore, it is necessary to improve the mixing process of active materials and conductive agent to improve its dispersity, and to keep the amount of black carbon in a certain range (usually less than 1.5%), it can play a role in the battery liquid absorption and retention.

At present, conductive carbon black is still dominated by Super-p, a conventional conductive agent.  Super-p is a conductive carbon black prepared by MMM method. It is made of primary particles with a diameter of about 40nm (Primary particle) agglomerated into primary aggregates with a diameter of 150-200nm (secondary particle), and then processed by soft agglomeration and manual compression. The overall shape is like grape ball chain. The main function of super-P in lithium-ion battery is to disperse the primary aggregates of 150-200nm around the active material to form a multi-chain conductive network, so as to reduce the physical internal resistance of the battery and improve the electronic conductivity. Super-p has the ability to absorb and hold the electrolyte (the OAN value of super-P is 6.4 mL /g), which improves the conductivity of the ions. Note that super-P does not store lithium and can be used for both cathode and anode.

Ketjen Black is also a high energy efficiency, high purity conductive carbon black for lithium batteries. Ketjen Black enjoys a high reputation in the industry for its unique shape and high conductivity. Compared with other conductive carbon black used in batteries, Ketjen Black has a unique branching form. The advantage of this form is that the conductive body has many conductive contact points and branch chains form many conductive paths, so it only needs a small amount of addition to achieve high conductivity (other carbon black is mostly spherical or flake, so it needs a high amount of addition to achieve the required electrical properties). Because of its ultra high conductivity, it can be added much less than other conductive carbon black, so it can be filled with more active materials, greatly improving the current density and capacity of the battery, thus extending the life of the battery. Another unique advantage of Ketjen Black is that the resistance of the battery does not increase due to the volume change during charging and discharging. This is because of the branch chain form of Ketjen Black, and there is full contact between the active materials, will not lose contact because of the change of the gap.

TOB can supply advanced conductive carbon materials (Sup-P, Sup-C45, Sup-C65, KS-6) and carbon nanotubes as battery conducive additive materials for battery manufacturers.