Patent Application
20150194712
Illustrative embodiments of the disclosure are generally directed to battery packs for electric vehicles (EVs), and other directly or indirectly use battery pack. More particularly, illustrative embodiments of the disclosure are directed to an EV battery pack with battery cooling assembly and a method which facilitate uniform and efficient cooling of EV batteries.
Due to the requirements of a high efficiency, low-cost system to transfer heat which is generated by battery cells with minimum power and volume, EV battery packs may utilize a liquid-cooled pad.
Accordingly, an EV battery pack with battery cooling assembly and method which facilitate uniform and efficient cooling of EV batteries may be desirable.
Illustrative embodiments of the disclosure are generally directed to an electric vehicle battery pack with battery cooling assembly. An illustrative embodiment of the electric vehicle battery pack includes an array of battery cells each cell having an upper cell surface and a lower cell surface, the lower cell surface having a positive and a negative terminal; and a thermal assembly in thermally-conductive contact with the upper cell surfaces of the array.
Illustrative embodiments of the disclosure are further generally directed to a battery pack cooling method. An illustrative embodiment of the battery pack cooling method includes inverting an array of battery cells of an electric vehicle battery pack having an upper cell surface and a lower cell surface, the lower cell surface having a positive and a negative terminal; applying a thermal assembly to the upper cell surfaces of the array; and circulating coolant through the thermal assembly.
Illustrative embodiments of the disclosure will now be described, by way of example, with reference to the accompanying drawings, in which:
The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable users skilled in the art to practice the disclosure and are not intended to limit the scope of the claims. Moreover, the illustrative embodiments described herein are not exhaustive and embodiments or implementations other than those which are described herein and which fall within the scope of the appended claims are possible. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
Referring initially to
Each battery cell 3 may include an upper battery cell surface 4 having a negative terminal 5 and a positive terminal 6. Each battery cell 3 may further include a lower battery cell surface 7 which is opposite the upper battery cell surface 4, a pair of spaced-apart end battery cell surfaces 8 and a pair of spaced-apart side battery cell surfaces 9 extending between the end battery cell surfaces 8. Each battery cell 3 may contain an electrolyte solution 12. A vent conduit 14 may communicate with the electrolyte solution 12. At least one end vent opening 16 which communicates with the vent conduit 14 may be provided in one of the end battery surfaces 8. Additionally or alternatively, at least one side vent opening 20 may be provided in one of the side battery surfaces 9 of each battery cell 3.
The battery cooling assembly 22 may include a battery pack cooling pad 24. In some embodiments, the battery cooling pad 24 may be generally elongated and rectangular with a battery contact surface 25, a pad outer surface 28 and a pair of side pad surfaces 26 and a pair of end pad surfaces 27 extending between the battery contact surface 25 and the pad outer surface 28. The battery cooling pad 24 may include any thermally-conductive metal, plastic and/or other material to increase heat transfer between battery cells and cooling pad.
As further shown in
As shown in
With the battery cell array 2 in an inverted position and the upper battery cell surface 4 facing downwardly and the lower battery cell surface 7 facing upwardly, the battery pack cooling pad 24 may be placed in thermally-conductive contact with the lower battery cell surfaces 7 of the respective battery cells 3. The lower battery cell surfaces 7 and the battery contact surface 25 of the battery pack cooling pad 24 may be rendered sufficiently smooth that the battery pack cooling pad 24 can “stick” to the battery cells 3 seamlessly. As shown in
In exemplary application, the battery cell array 2 is inverted such that the upper battery cell surfaces 4 of the respective battery cells 3 face downwardly and the lower battery cell surfaces 7 face upwardly. The battery cooling pad 24 is applied to the lower battery surfaces 7 of the battery cells 3, as was heretofore described with respect to
The battery array frame 40 may have any design or construction which is suitable for the purpose. In some embodiments, the battery array frame 40 may be thermally conductive metal and/or other material and may include multiple corner frame members 41 which are placed at the respective corners of the battery cell array 2. Side frame members 42 may extend between the corner frame members 41 along the respective longitudinal edges of the battery cell array 2. The side frame members 42 may be fitted with frame mount brackets 44 which facilitate bolted and/or other attachment of the EV battery pack 1 to the electric vehicle and to make the cells are compressed inside vehicle to extend the life of battery cells.
Throughout operation of the EV battery pack 1, heat may be generated inside the battery cells 3 of the battery cell array 2. Liquid coolant 35 may be circulated through the coolant inlet 30, coolant path 34 and coolant outlet 32, respectively. Thus, heat is dissipated from the interiors of the battery cells 3 to the circulating coolant 35. The battery cell is filled full or partially with electrolyte solution 12 (
With the more uniformed temperature field within each battery cell 3 and increased heat transfer to the lower battery cell surfaces 7, the temperature of the lower battery cell surfaces 7 may be raised. This may substantially improve the cooling pad heat transfer condition due to larger delta temperature between the coolant and the cell to facilitate a lower coolant fluid rate and a higher coolant fluid temperature. The lower requirement on cooling fluid rate and temperature may be met by lowering the cooling fan speed and/or lowering or eliminating extra AC cooling to reduce cooling system cost and increase vehicle fuel economy and available power from the EV battery pack 1. In the event that pressure accumulates in the battery cells 3 and exceeds a predetermined threshold, any gas and/or electrolyte solution 12 may be vented from the battery cells 3 through the end vent opening or openings 16 and/or the side vent opening or openings 20. If due to the upside down installation of the cell, the vent and CID are located at bottom and manufacture prefers to vent gas out of the cell first, special design is needed. For example, a tube 14 may be constructed inside the cell to reach above the electrolyte level to vent out the gas first.
Referring next to
Although the embodiments of this disclosure have been described with respect to certain exemplary embodiments, it is to be understood that the specific embodiments are for purposes of illustration and not limitation, as other variations will occur to those of skilled in the art.
