Experimental investigation on a novel liquid-cooling strategy by coupling with graphene-modified silica gel for the thermal management of cylindrical battery

Highlights: • A new liquid-cooling structure is proposed by introducing modified silica gel (SG). • Adding graphene oxide (GO) enhances the thermal conductivity of GO-SG effectively. • GO-SG enhances the heat transfer capability from the cells to the cooling tubes. • The water cooling battery module with GO-SG shows excellent cooling performance. • The flexible GO-SG can offer the battery module better anti-collision performance. -- Abstract: As the most widely used battery thermal management (BTM) technology in pure/hybrid electric vehicles, liquid cooling is facing challenge of enhancing the heat transfer capability between the cooling tubes and the curved surface of cylindrical cells. In this work, a kind of graphene oxide (GO) -modified silica gel (GO-SG) is prepared and simply filled in the space between the cylindrical cells and water cooling tubes. The addition of GO endows the GO-SG with enhanced thermal conductivity to transfer the generated heat to the tubes effectively, thus giving rise to a superior cooling and temperature-uniformed performance of the battery module. For instance, during the fast charging process of 2 and 3C, the maximum temperature (T_max) of the water cooling module with GO-SG is as low as 37.7 and 42.0 °C, and the corresponding temperature difference (ΔT) is controlled below 4 and 5 °C, respectively. During the cycling tests, the T_max and ΔT can be maintained below 40 and 4 °C, respectively. We believe that this approach may open new thoughts for the structural optimization of the liquid cooling technology and thus promote the development of the BTM systems.