Multi-dimensional modeling of large-scale lithium-ion batteries

Multi-dimensional model of large-scale lithium-ion batteries is developed. The model is based on equivalent circuit model (ECM) which is capable of dynamic response simulation. Model parameters are functions of both state of charge and temperature, which are implemented by bilinear interpolation method. Local degradation effects such as capacity fade and resistance growth are incorporated into the multi-D model by empirical method. Local distributions of current, potential, temperature, state of charge (SOC), and state of health (SOH) are observed with the developed model. It is found that local degradation worsens under severe operating condition. Low thermal conductivity of a battery results in non-uniform SOH distribution. Simulation result shows good agreement with experiment data under various operation modes.