Control-Oriented Galerkin-Spectral Model for 3-D Thermal Diffusion of Pouch-Type Batteries

Control-oriented thermal models are essential for onboard temperature monitoring of lithium-ion batteries in automobile applications. This work develops a Galerkin-spectral model for the three-dimensional (3-D) thermal diffusion in pouch cells. First, a full-order model that depicts the battery thermal phenomenon is introduced from a physical point of view. Considering different physical properties in each area, we apply a space decomposition approach to decouple the interactive thermal effects between the cell core and tabs. Then, mild approximations are made to generate a more succinct model governed by the partial and ordinary differential equations. Finally, a low-order representation is extracted from the original infinite-dimensional system by employing spectral expansion on the spatiotemporal variable. Experimental and simulation studies indicate satisfactory reduced-order performance and practical validity of the proposed model.