STUDY OF THE EFFECTS OF CARBON BLACK IN EXPANDER ON CAPACITY OF NEGATIVE ELECTRODE IN TRACTION BATTERY

The expander materials are the main components of the negative electrode, which have the
properties of increasing the capacity and number of cycles per use, and include barium sulfate, sodium
lignosulfonate, and carbon black. In particular, carbon black has the function of being an electrical
conductor due to its property of aggregating a large number of particles in a branched or chain-like
manner, with high porosity. However, the role of carbon black on the negative terminal capacity of
electric vehicle batteries is still unclear, and the optimum weight ratio is also unknown. The testing
equipment used includes electrochemical property testing using the cyclic voltammetry (CV), transmission
electron microscope (TEM) and scanning electron microscope (SEM) were used to investigate the capacity
of the negative electrode and to examine structure of the expander, respectively. From the study, it was
also found that capacity of the electrode was high when the amount of carbon black was equal to that
of lignosulfonate. This phenomenon is related to the structure of sodium lignosulfonate interacting with
carbon black to form groups, called lignosulfonate-carbon black cluster. The maximum capacity was
obtained when the weight ratio of carbon black: sodium lignosulfonate is 6:6