Battery Thermal Management: Heat Generation & Cooling

This document provides an introduction to thermal management for batteries, covering mechanisms of heat generation in ternary (NCM) and lithium iron phosphate (LFP) batteries. It explains heating power formulas (P=I²R, P=IV-U) and factors affecting DC internal resistance, such as temperature, SOC, and charge/discharge rates. The document details principles of irreversible and entropy heat generation, and presents a battery thermal coupling model using equivalent circuit models in MATLAB/Simulink. CFD simulation processes are outlined, including pre-processing, solver, and post-processing steps. Heat dissipation methods—natural cooling, air cooling, and liquid cooling—are compared in terms of cost and effectiveness. Design and optimization of thermal management systems are discussed, focusing on cold plate design, flow deviation, and material selection (e.g., Al 3003, 6063-T6, 6061-T6). Components of a thermal management system are explained, including heat sources, radiators, condensers, coolant circulation (pump, pipes), temperature control (sensors, thermostat, electronic expansion valve), air cooling (fan), and control systems. A liquid cooling unit schematic is provided, highlighting chiller components and key selection indicators like refrigeration capacity.