Electrochemical-thermal modeling and microscale phase change for passive internal thermal management of lithium ion batteries.

Abstract

A fully coupled electrochemical and thermal model for lithium-ion batteries is developed to investigate the impact of different thermal management strategies on battery performance. In contrast to previous modeling efforts focused either exclusively on particle electrochemistry on the one hand or overall vehicle simulations on the other, the present work predicts local electrochemical reaction rates using temperature-dependent data on commercially available batteries designed for high rates (C/LiFePO 4 ) in a computationally efficient manner. Simulation results show that conventional external cooling systems for these batteries, which have a low composite thermal conductivity (~1 W/m-K), cause either large temperature rises or internal temperature gradients. Thus, a novel, passive internal cooling system that uses heat removal through liquid-vapor phase change is developed. Although there have been prior investigations of phase change at the microscales, fluid flow at the conditions expected here is not well understood. A first-principles based cooling system performance model is developed and validated experimentally, and is integrated into the coupled electrochemical-thermal model for assessment of performance improvement relative to conventional thermal management strategies. The proposed cooling system passively removes heat almost isothermally with negligible thermal resistances between the heat source and cooling fluid. Thus, the minimization of peak temperatures and gradients within batteries allow increased power and energy densities unencumbered by thermal limitations.

Integrated Systems: Innovations and Applications

“…PCM is in fact a latent heat storage where the heat is absorbed or released when the material changes from solid to liquid and vice versa. A combination of these method is also exploited [77].…”

Thermal modelling and cost analysis for large-scale battery energy storage system (BESS) in grid-connected PV plant

“…where they proposed general models of battery thermal behaviour in [70][71][72][73][74][75][76] or specialized models for cold weather or lower range of temperature [23,77]. However, there is no such research work to investigate thermal behaviour of a utility-scale BESS.…”

“…In this thesis, exogenous parameters are the battery current and ambient temperature. Battery current (i.e., charge/discharge and idle regime) has direct influence on the battery cell temperature because of the ohmic and non-ohmic internal losses [74]. Also, the ambient temperature changes the temperature inside the container, which essentially changes cell temperature with some delay.…”