Investigation and optimization on cooling performance of a novel double helix structure for cylindrical lithium-ion batteries

Abstract

Abstract Liquid cooling system was critical to keep the performance of lithium-ion battery due to its good conductivity to keep battery working in a cool environment. In this study, a novel double helix cooling structure was designed for an 18650 lithium battery. The numerical simulation was carried out to investigate the effects of the coolant mass flow rate (M), helix groove pitch (P) and flow diameter (D) on cooling performance. The design points obtained by Latin hypercube sampling were calculated numerically. Kriging approximate model method was adopted to reduce computing time. Using Non-dominated Sorting Genetic Algorithm II obtained the Pareto solution, and the multiple criteria decision making (MCDM) algorithm was used to sort the optimal solution set. The results showed that increasing mass flow rate can effectively lower the maximum temperature and temperature difference of the battery within a certain range of mass flow rate. When the mass flow rate increased to a certain value, the benefit from increasing the mass flow was limited. And the pitch and diameter would also have a tendency to the decrease of the maximum temperature or even the opposite result when they exceeded a certain value. The best cooling performance can be obtained when the mass flow rate is 1.94 × 10−3 kg/s, the pitch is 100 mm and the diameter is 0.4 mm. The novel cooling structure proposed in this study can provided a new approach for the structure design of the liquid-cooled cylindrical battery thermal management system.