Acetylene black is a type of carbon black that is obtained by refining the gas produced as a byproduct during the thermal cracking of calcium carbide or crude oil (naphtha) to obtain acetylene, which has a purity of over 99%. After continuous pyrolysis, it is converted into acetylene black. The acetylene gas is heated to a temperature of 800℃ or higher, and the decomposition reaction is initiated. Since this is an exothermic reaction, it can proceed automatically. In order to obtain stable quality, the reaction temperature should be maintained at around 1800℃. The temperature inside the reactor can be controlled using a water-cooled jacket on the outside of the reactor.
Acetylene black is used as a negative electrode material in nickel-hydrogen batteries, together with the separator and electrolyte. Compared to furnace black, it has a more developed crystal and secondary structure, resulting in better conductivity and fluid absorption. Due to the low content of heavy metal impurities, it has less self-discharge loss and is mainly used for the negative electrode of nickel-hydrogen batteries. Acetylene black can also be used as a conductive material in supercapacitors.
The product appears as a black ultrafine powder with a relative density of 1.95 (nitrogen displacement method). The apparent density is 0.2-0.3 g/cm3. The average particle size is 30-45 nm. The specific surface area is 55-70 m2/g. The iodine adsorption value is 60-80 gI2/kg. Acetylene black has high purity, with a carbon content greater than 99.5%, hydrogen content less than 0.1%, and oxygen content ranging from 0.07% to 0.26%. The pH value is 5-7. The electrical resistivity is extremely low, and it has excellent conductivity, thermal conductivity, and anti-static effects.
Acetylene black is a commonly used material for the anode of manganese dry batteries. It is used together with manganese dioxide and electrolyte. Compared to furnace black, it has a more developed crystal and secondary structure, resulting in better conductivity and fluid absorption. Due to the low content of heavy metal impurities, it has less self-discharge loss and better storage performance. Acetylene black almost dominates the entire market in this field. It can be predicted that it will continue to be used in dry batteries in the future.