Conductive carbon black is a conductive agent and an important auxiliary material for lithium batteries. Compared with other conductive agents, conductive carbon black has better comprehensive performance and is currently the mainstream conductive agent. With the accelerated penetration of downstream new energy vehicles and the sharp increase in demand for lithium batteries, the supply of overseas conductive carbon black is in short supply and the price is high. Domestic companies have begun to start localization and gradually achieve technological breakthroughs.
Conductive carbon black is the mainstream lithium battery conductive agent
Lithium-grade conductive carbon black is currently the most widely used conductive agent for lithium batteries:
Carbon black is a form of carbon, which can be divided into rubber carbon black and non-rubber carbon black according to the application. Non-rubber carbon black is also called special carbon black, including chroma carbon black, conductive carbon black, plastic Use carbon black and special carbon black, etc. Among them, conductive carbon black is a kind of high-performance carbon black and semiconductor material, which can impart conductivity or antistatic effect to products. At present, it is mainly used in cable shielding materials, battery conductive agents, and static conductive plastics. Lithium-grade conductive carbon black has good conductivity and low price, and is currently the mainstream conductive agent for lithium batteries.
Conductive agent is an important auxiliary material to improve the conductivity of lithium batteries. Specifically, when the positive and negative electrode materials are pulped, the conductive agent is mixed and coated on the current collector together:
(1) The conductivity of the positive electrode material itself is poor: Among the positive electrode materials, nickel-cobalt-manganese ternary is a semiconductor, and lithium iron phosphate is an insulator, which has poor conductivity, which is not conducive to the performance of the battery rate performance. Add a conductive agent to make the conductive material fill the gaps between the active materials of the positive electrode material, form a good conductive network, and improve the conductivity of the positive electrode material.
(2) The conductivity of the negative electrode material decreases after repeated expansion and contraction: materials such as graphite, silicon carbon, and hard carbon have good electrical conductivity, but during multiple charge and discharge processes, the volume repeatedly expands and shrinks as lithium is deintercalated, and the contact between particles deterioration, increased internal resistance, and reduced electrical conductivity. Adding a conductive agent helps to maintain the conductivity of the negative electrode material.