LAUSR

Abstract In this study, a novel battery thermal management system based on AgO nanofluid is designed for 18650/21700-types lithium-ion batteries to maintain the maximum temperature and temperature homogeneousness in the battery pack within the optimum range. The influences of discharge C-rate, nanofluid volume fraction, and inflow velocity on the thermal efficiency of the battery pack at high discharge rates (3C, 5C, and 7C) are analyzed numerically. A meticulous comparison between 18650 and 21700 battery packs is conducted comprehensively. The result indicated that the maximum temperature and temperature difference decreased significantly with an increase in the inflow velocity and nanofluid volume fraction. When the liquid cooling system operated under a 7C discharge rate at the optimal inflow velocity and nanofluid volume fraction as a coolant, the maximum temperature and temperature difference of the battery pack is held below 305.59 K and 1.07 K, respectively. Comparing the 18650 and 21700-types lithium-ion battery thermal management systems revealed that the new format—21700-type battery pack—would have a promising future.