a group of researchers from the hong kong university of science and technology studied the effect of a nickel foam-paraffin wax composite on the thermal management of a high-powered lithium-ion battery used in electric vehicles (ev) and hybrid-electric vehicles (hev).

(wikimedia commons)

the composite was tested against natural air cooling and cooling with a phase-change material to see how the composite would affect the system temperature.

the abstract from the report stated:

“it is necessary for electric vehicles (evs) and hybrid electric vehicles (hevs) to have a highly efficient thermal management system to maintain high powered lithium ion batteries within permissible temperature limits. in this study, an efficient thermal management system for high powered lithium ion batteries using a novel composite (nickel foam-paraffin wax) is designed and investigated experimentally.

“the results have been compared with two other cases: a natural air cooling mode and a cooling mode with pure phase change materials (pcm). the results indicate that the safety demands of lithium ion batteries cannot be fulfilled using natural air convection as the thermal management mode. the use of pcm can dramatically reduce the surface temperature within the permissible range due to heat absorption by the pcm undergoing phase change.

“this effect can be further enlarged by using the nickel foam-paraffin composite, showing a temperature reduction of 31% and 24% compared to natural air convection and pure pcm, respectively under 2 c discharge rate. the effect of the geometric parameters of the foam on the battery surface temperature has also been studied.

“the battery surface temperature decreases with the decrease of porosity and the pore density of the metal foam. on the other hand, the discharge capacity increases with the increase in porosity, but decreases with pore density.”

the researchers concluded that the composite could be a cost-effective method for the thermal management of lithium-ion batteries because of the lower cost of nickel as compared to other metals.

read the full report at https://www.researchgate.net/publication/308038092_experimental_investigation_of_a_

passive_thermal_management_system_for_high-powered_lithium_ion_batteries_using_nickel_foam-paraffin_composite.