Quantitative performance analysis of graphite-LiFePO4 battery working at low temperature

• Simulation of graphite-LiFePO4 battery is performed by pseudo 2-D numerical analysis.
• Method for the optimization of the electrode working at low temperature is proposed.
• Relationship between parameters and performances is analyzed.
• Performance profile varied with intrinsic and extrinsic properties is drawn.
• Particle radius which maximizes the performance at low temperature is calculated.

Although recent development of lithium ion batteries with high energy and power density enables one to actuate electrical vehicles, many challenges concerning the operational sensitivity in extreme climate conditions still exist. In this work, we investigate the effect of three independent parameters on the performance of a lithium ion battery under low temperatures via computational modeling: (1) the diffusion coefficients of lithium ion, (2) the lithiation rate constants at the surface of active material, and (3) the particle radius of active material. From the computational approach, the regions associated with maximum capacity and voltage value are identified in the parameter space. To simulate the operation of battery at low temperature, the particle radius which is independent of temperature is chosen as the control parameter, and the temperature dependence of diffusion coefficient and reaction rate constant is also calculated. By correlating the three parameters with the temperature, the optimized particle radius which can exert high capacity and voltage under low temperature was found.