Numerical Simulation of Transient Voltage Response of Lithium-Ion Secondary Battery

Abstract

To apply lithium-ion secondary batteries to electric power storage apparatus in distributed power generation systems, electric vehicles, etc., it is necessary to take into consideration their transient cell voltage response to the change of the charge/discharge current. The authors, therefore, develop a simulation method that can accurately calculate this transient cell voltage response of lithium-ion secondary battery even when the cell temperature and state of charge vary as the time proceeds in the time-dependent calculation. The transient cell voltage responses of a commercially available small-sized lithium-ion secondary battery to the square-wave charge/discharge and discharge currents are numerically simulated, and the calculation results are compared and examined with the experimental results. It is made clear that the calculation results coincide well with the experimental results not only for the charge/discharge current with short period under constant temperature and state of charge condition, but also for the discharge current with long period under variable temperature and state of charge condition, indicating the validity of the developed simulation method.