Graphite conducting agent KS / SFG for lithium cell anode and cathode

In the charge discharge cycle of lithium battery, when there is current passing through the positive and negative electrodes, there will be a net reaction, indicating that the electrode has lost its original equilibrium state, and the electrode potential will deviate from the equilibrium potential, resulting in the commonly known polarization. The polarization of lithium battery can be divided into ohmic polarization, electrochemical polarization and concentration polarization. Polarization voltage is an important parameter for electrochemical reaction in lithium-ion batteries. If the polarization voltage is unreasonable for a long time, the precipitation of lithium metal in the negative electrode will be accelerated, and in serious cases, it will pierce the diaphragm and lead to short circuit. According to the initial experimental data of lithium battery, the conductivity of living material alone is not enough to meet the requirements of electron migration rate.
The conductive agent of lithium-ion battery has two important uses in the whole lithium-ion battery: conducting electrons and absorbing electrolyte; therefore, the addition of conductive agent can improve the rate, circulation, reduce the internal resistance and increase the battery capacity of lithium-ion battery; the conductive agent can not be added more or less, more will not only affect the energy density, but also affect the positive electrode capacity.
The primary function of conductive agent is to improve the electronic conductivity. In order to ensure that the electrode has good charging and discharging performance, a certain amount of conductive agent is usually added to the electrode plate to collect the micro current between the active substances and between the active substances and the current collector, so as to reduce the contact resistance of the electrode, accelerate the movement rate of electrons, and effectively improve the lithium ion in the electric field Therefore, the charge discharge efficiency of the electrode can be improved. In addition, the conductive agent can also improve the processability of the electrode, promote the infiltration of electrolyte on the electrode, and effectively improve the migration rate of lithium ion in the electrode material, reduce the polarization, so as to improve the charge discharge efficiency of the electrode and the service life of the lithium battery.
Conductive graphite also has good conductivity, which is basically artificial graphite. Compared with artificial graphite as anode material, artificial graphite as conductive agent has smaller particle size, generally 3 ~ 6 μ m, more developed pores and specific surface, and the form of point contact between particles can form a certain scale of conductive network structure, which is conducive to improving the compaction of electrode particles and improving the quality of electrode The conductive graphite has better compressibility and dispersion, which can improve the volume energy density of the battery and the process characteristics of the electrode piece. It is generally used with carbon black.
Graphite conductive agents include KS-6, KS-15, SFG-6, SFG-15.
KS-6: large particle graphite powder, feathery, with certain lithium storage function, used as cathode in actual production.
SFG-6: suitable for negative electrode as conductive agent, flake artificial graphite can improve the surface performance of negative electrode.

SEM pictures of various common conductive agents