Thermal performance of direct two-phase refrigerant cooling for lithium-ion batteries in electric vehicles

•Direct two-phase refrigerant cooling is proposed for batteries in electric vehicles.•Thermal performance of the refrigerant cooling is measured under vehicle conditions.•The most effective performance is observed at the vapor quality of 0.85.•The cell temperature limit of 45 °C is satisfied under harsh environments.•During aging, the refrigerant cooling provides 16.1% higher battery capacity.