Conductive carbon black as anode and cathode conductive agent of lithium battery， Ketjenblack（EC300J、EC600JD、 ECP、ECP600JD）

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.
Ketjenblack: high efficiency superconducting carbon black specially used for lithium batteries, with branched chain shape, high purity and excellent conductivity. Compared with other conductive carbon black used for batteries, Keqin black has unique branched chain shape. The advantage of this form is that the conductor has many conductive contact points, and the branched chain forms more 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 conductivity.
Ketjenblack EC300J, ketjenblack EC600JD, carbon ECP, carbon ECP600JD. Among them, EC-300J is mainly used for Ni MH and Ni Cd batteries; ECP and ECP-600JD are mainly used for lithium batteries with high rate, large capacity and current density, especially ECP-600JD.

SEM of the mixture of ECP and positive active material

Compared with acetylene black, ECP has more porosity and more primary particles, so it has better liquid absorption and more conductive paths
ECP has excellent electronic conductivity at low addition

1. Compared with acetylene black, ECP has more porosity and stronger liquid absorption. In the process of dispersion, ECP absorbs a lot of NMP;

2. In the process of lithium-ion battery slurry mixing, directly adding ECP powder will lead to high slurry viscosity, ECP is difficult to disperse, and it is easy to form aggregates in the cathode material;

3. Therefore, the preparation of ECP dispersion can effectively solve the problem of dispersion, ensure the uniform dispersion of ECP in the active material, and play an excellent conductivity.

Application suggestions

1. Recommended for power battery and high rate battery
2. Compared with SP, it is suggested to add 50% - 70% of sp
3. It is suggested to use high speed disperser to make slurry
4. Suggestions for use of sub packed samples: before use, please spread out and dry (120 ℃, 1-2 hours)