NOVELTY - The device has a plate defining a pair of spaced apart channels, an inlet port in communication with one of the channels and an outlet port in communication with the other channel and spaced opposite to the inlet port. Another plate is arranged for thermal energy exchange with a secondary battery cell (10) and arranged in contact with the former plate to define a cross-flow channel. The cross-flow channel is interconnected the former channel and the latter channel. A phase change material is placed and disposed within a pair of cavities.    USE - Thermal management device for dissipating thermal energy from a secondary battery cell i.e. lithium ion secondary battery cell, of a secondary battery i.e. secondary battery pack, for an electric vehicle (EV) and a hybrid EV (HEV) e.g. plug-in HEV (PHEV), during an operation of the secondary battery. Can also be used for lithium ion polymer, lithium iron phosphate, lithium vanadium pentoxide, lithium copper chloride, lithium manganese dioxide, lithium sulfur, lithium titanate, nickel metal hydride, nickel cadmium and nickel hydrogen secondary battery cells, and for a non-automotive application e.g. household and industrial power tools and machineries and electronic device.    ADVANTAGE - The device provides uniform heat transfer between the device and the secondary battery cell, thus allowing better temperature control for the secondary battery during the operation of the secondary battery. The cross-flow channel performs thermal conduction within the latter plate to provide uniform secondary battery cell temperature even if measurable temperature of fluid increases from the inlet port to the outlet port such that the secondary battery is air cooled in a better manner to minimize uneven temperature distribution, thus providing uniform temperature distribution across the secondary battery cell, and hence maximizing performance, and prolonging service life of the secondary battery. The inlet port and the outlet port can be enlarged due to the cross-flow channel so as to minimize pressure drop of the fluid across the secondary battery cell and/or secondary battery.    DESCRIPTION OF DRAWING(S) - The drawing shows an exploded perspective view of a secondary battery including a set of secondary battery cells and secondary battery modules.    Secondary battery cell (10)    Secondary battery (12)    Secondary battery module (16)    Positive cell tab (18)    Negative cell tab (20)