Claims:
WE CLAIM:
1. A battery pack system (100), comprising:
at least one battery module (140), comprising at least one battery cell (141);
at least one supporting structure (142), configured for providing structural support to the at least one battery cell (141);
an inlet (111) for coolant (160) entrance into the battery pack system (100), the inlet (111) coupled to at least one top coolant compartment (121), wherein the top coolant compartment (121) has at least one orifice (150) configured to provide coolant (160) into the battery module (140) such that the coolant (160) flows from top to bottom of the battery module (140) while heating or cooling one or more battery cells (141); and
an outlet (112) for coolant (160) exit from the battery pack system (100), the outlet (112) coupled to at least one bottom coolant compartment (122), wherein the bottom coolant compartment (122) is operatively coupled to at least one battery module (140), wherein the battery pack system (100) provides temperature regulation of the at least one battery cell (141) by circulation of the coolant (160) from the top coolant compartment (121) to the bottom coolant compartment (122) via the at least one battery module (140), such that due to the direct contact of the coolant (160) with the at least one battery cell (141), heat is transferred between the coolant (160) and the at least one battery cell (141).

2. The battery pack system (100) as claimed in claim 1, wherein the top coolant compartment (121) has at least one orifice of a rectangular, circular shape or an oval shape.

3. The battery pack system (100) as claimed in claim 1, wherein the electrical connections between the battery cells (141) are insulated with silicone, epoxy or plastic sheet.

4. The battery pack system (100) as claimed in claim 1, wherein the battery cells (141) have an electrically insulating but thermally conducting material layer on outer walls.

5. The battery pack system (100) as claimed in claim 1, wherein the battery cells (141) are arranged in a triangular, a rectangular, a pentagonal, a hexagonal, a heptagonal, a octagonal or a circular arrangement.

6. The battery pack system (100) as claimed in claim 1, wherein the battery cells (141) are arranged in a staggered or inline arrangement.

7. The battery pack system (100) as claimed in claim 1, wherein the battery modules (140) are arranged adjacent to each other.

8. The battery pack system (100) as claimed in claim 1, wherein the battery modules (140) are stacked upon one another.

9. A thermal management system (800) for the temperature regulation of the battery pack system (100) as claimed in claim 1 comprising:
at least one battery pack system (880), wherein the battery pack system (880) is operatively coupled to at least one heat exchanger (884);
a pump (883) operatively coupled to a heater (882), the heater (882) is operatively coupled to a reservoir (881), wherein the reservoir (881) is operatively coupled to the at least one battery pack system (880);
a coolant filled into the system (800) through the reservoir for heat transfer between the battery pack system (880), the heater (882) and the heat exchanger (884), the coolant; and
a two-way valve (885) operatively coupled to the heat exchanger (884), wherein the two-way valve (885) is used for letting the coolant flow through the heat exchanger (884) or bypassing the heat exchanger (884).
, Description:BATTERY PACK SYSTEM WITH TEMPERATURE REGULATION

FIELD OF INVENTION

[001] The present invention relates generally to the field of batteries and specifically relates to system and methods for temperature regulations in battery pack system comprising plurality of battery cells.

BACKGROUND

[002] A battery pack system includes multiple modules comprising plurality of battery cells. Battery pack systems are widely used in various power storage devices, vehicles, etc. Vehicles using electric power for all or a portion of their motive power (e.g., Battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and the like, collectively referred to as “electric vehicles”), may provide a number of advantages as compared to more traditional gas-powered vehicles using internal combustion engines. Over the rising concerns of oil costs, climate change and energy security, efforts to promote energy efficient electric vehicles have grown. Energy efficient electric vehicles provide overall reduced air emissions compared to conventional combustion vehicles.

[003] The performance of power storage devices and electric vehicles depend on a battery pack system. It is known that temperature has an influence over life and safety of a battery pack system. For power storage and electric vehicle applications, a battery pack system experiences high charge and discharge rates and the internal chemical reactions of the battery cell generates heat.

[004] The battery pack system needs to be charged and discharged at a suitable temperature range to minimize the battery cell life degradation. Thus, it becomes necessary to precondition the battery pack system before charging and discharging.
[005] Thus, a thermal management system for a battery pack system is required to keep the battery cell temperature within an optimum range to achieve desired performance in varied climate conditions before and during charging as well as discharging the battery pack system.

[006] The battery cells are closely arranged in the battery modules to get maximum packing efficiency and are electrically connected in series or parallel. Existing battery pack systems comprise of heat conducting tubes in contact with side surfaces of the battery cells. These heat conducting tubes pass through narrow gaps between rows of cells. Such system requires labor and cost intensive method for assembling the battery pack system, which increases the cost of the system. The present invention provides a battery pack system overcoming the need for special assembly methods, thus reducing the cost.

SUMMARY

[007] This summary is provided to introduce a selection of concepts in a simple manner that is further described in the detailed description of the disclosure. This summary is not intended to identify key or essential inventive concepts of the subject matter nor is it intended for determining the scope of the disclosure.

[008] In one embodiment, a battery pack system is disclosed. The battery pack system comprises at least one battery module having at least one battery cell and supported by at least one supporting structure. Further, the battery pack system provides an inlet for coolant entrance into the battery pack system, the inlet is coupled to at least one top coolant compartment, wherein the top coolant compartment has at least one orifice through which the coolant flows into at least one bottom coolant compartment. Furthermore, an outlet for coolant exit from the battery pack system is provided, the outlet is coupled to at least one bottom coolant compartment. Further, the coolant absorbs or discharges the heat from or to one or more battery cells as it flows through the arrangement of at least one battery cell.

[009] The battery cells are electrically connected according to the voltage and current requirements from the battery pack system and any number of such electrical connections are possible.
[0010] In accordance with another embodiment of the present invention, a thermal management system is provided for the heating and cooling of the battery pack system.

BRIEF DESCRIPTION OF DRAWINGS

[0011] Embodiments of the disclosure will now be described, by way of example, with reference to the accompanying drawings, in which:

[0012] Fig. 1 is a perspective view of the battery pack system, in accordance with one embodiment of the present invention.

[0013] Fig. 2 is a perspective view of internal structure of the battery pack system shown in Fig.1.

[0014] Fig. 3 is a section view of the battery pack system in Fig.1 showing flow of coolant .

[0015] Fig. 4 is a perspective view of internal structure of the battery pack system shown in Fig.1 with circular orifices instead of rectangular orifices, in accordance with another embodiment of the present invention.

[0016] Fig. 5 is a section view of the battery pack system in Fig. 1 with liquid seals, in accordance with some other embodiment of the present invention.

[0017] Fig. 6 is a section view of a battery module of the battery pack system in Fig. 1 showing staggered arrangement of the battery cells and flow of the coolant, in accordance to one embodiment to the present invention.

[0018] Fig. 7 is a section view of a battery module of the battery pack system in Fig. 4 showing inline arrangement of the battery cells and flow of the coolant, in accordance to another embodiment to the present invention.

[0019] Further, persons skilled in the art to which this disclosure belongs will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION

[0020] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications to the disclosure, and such further applications of the principles of the disclosure as described herein being contemplated as would normally occur to one skilled in the art to which the disclosure relates are deemed to be a part of this disclosure.

[0021] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.

[0022] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or a method. Similarly, one or more devices or sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, other subsystems, other elements, other structures, other components, additional devices, additional sub-systems, additional elements, additional structures, or additional components. Appearances of the phrase “in an embodiment”, “in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

[0024] Embodiments of the present disclosure will be described below in detail with reference to the accompanying figures.

[0025] For exemplary and simplicity purpose, the present disclosure and the corresponding drawings explain a battery pack system comprising “cylindrical battery cells”. However, it is to be noted that the various embodiments of the present disclosure are applicable for battery cells having different geometries in the battery pack system. Other types of battery cell geometries include prismatic cell geometry, pouch cell geometry, etc.

[0026] Referring to Fig.1, a battery pack system 100 provided for the temperature regulation of the battery cells 141. Referring to Fig.2 and Fig.3, the battery pack system 100 of Fig.1 comprises of two battery modules 140 is disclosed. As used herein, a battery module is a group of electrically connected battery cells arranged together with supporting structure. Each battery module 140 comprises of battery cells 141 arranged adjacent to each other held together with the supporting structures 142. The supporting 142 may be plates with provision of slots in which the battery cells 141 may fit. The battery casing 130 encloses and holds the battery modules 140 together. One or more such battery modules constitute the battery pack system 100.

[0027] The present invention does not intend to limit the number of battery modules 140 in a battery pack system 100. One or more battery modules 140 may be used by extending the casing structure 130 of the battery pack system 100. The battery modules 140 may be arranged upon one another or adjacent to each other, i.e. in a horizontal or a vertical structure.

[0028] The arrangement pattern of the battery cells 140 may be staggered or inline. Moreover, the battery cells may be in a triangular, square, pentagonal, hexagonal arrangement or any possible geometry. The present invention does not intend to limit the arrangement pattern of the battery cells 141 inside the battery modules 140 or the arrangement of the battery modules 140 inside the casing 130.

[0029] Further, the battery pack system 100 comprises openings for coolant 160 to flow in and out of the system. The battery pack system 100 comprises a coolant inlet 111 and a coolant outlet 112 coupled to external pipes through which the coolant 160 can be circulated. The battery pack system 100 further comprises of a compartment 121 placed at the top of battery pack system 100, wherein the top coolant compartment 121 is coupled to the inlet 111, wherein the top coolant compartment 121 has rectangular orifices 150. The orifices 150 are provided for the flow of coolant 160 from the compartment 121 into the battery modules 140. The coolant 160 flowing through the battery modules 140 absorbs or discharges the heat from or to the battery cells 141. Further, a bottom coolant compartment 122 is provided for collecting the coolant 160 from the battery modules 140, wherein the bottom coolant compartment 122 is coupled to the coolant outlet 112.

[0030] The coolant 160 having lower temperature than battery cell 141 temperature is supplied for cooling the battery cell 141. Herein, the coolant 160 absorbs the heat from the battery cells 141 and flows out of the battery pack system 100. The heat absorbed from the coolant 160 may be discharged to an external thermal management system to keep the cycle continuous. Similarly, when heating of the battery cell 141 is required, coolant 160 having higher temperature than battery cell 141 is supplied. Herein, the coolant 160 discharges the heat to the battery cells 141 and flows out of the battery pack system 100. The amount of heat released from the coolant 160 may be gained again from an external thermal management system to keep the cycle continuous.

[0031] In accordance with another embodiment of the present invention, as illustrated in Fig.4, the top coolant compartment 121 comprises circular orifices 450. The top coolant compartment 121 may have various shapes of orifices for the coolant 160 flow.

[0032] The coolant 160 may include an electrically non conducting fluid such as oil, distilled water or any other fluid known in the art which is electrically insulating.

[0033] During the operation of battery pack system 100, impurities may enter the battery pack system 100 and contaminate the coolant 160. If the coolant 160 such as distilled water gets contaminated, it may start conducting electricity. The battery cells 141 generally used have open terminals and the contaminated coolant may conduct electricity among the battery cells 141, which is dangerous for the battery pack system 100. In accordance with some other embodiment of the present invention, liquid seals 570 are provided in the battery pack system 100 in the region where the electrical connections of the battery cells 141 are done. These liquid seals 570 block the flow of coolant into the electrical connections. The liquid seals 570 may be a plastic sheet wrapped around the electrical connections or silicone epoxy material filled in the electrical connections. Moreover, the battery cells 141 may be coated with thin plastic or insulating tape.

[0034] The battery cell 141 may be arranged in different arrangements inside the battery module 140. The arrangement of the battery cells 141 affects the flow of coolant 160 through the battery module 140. One such arrangement and the flow of coolant 160 is illustrated in Fig.6, wherein the battery cells 141 are arranged in a staggered arrangement. Another such arrangement and flow of coolant 160 is illustrated in Fig.7, wherein the battery cells 141 are arranged in an inline arrangement. The staggered arrangement as illustrated in Fig.6 is advantageous as it spreads the coolant 160 all over the surface of the battery cell 141, thus, uniform heat transfer from the surface of the battery cell 141 is ensured.

[0035] In accordance with another embodiment of the present invention, a thermal management system 800 is provided for the battery pack system as illustrated in Fig.8. The thermal management system 800 comprises of a battery pack system 880, a heater 882, a pump 883, a heat exchanger 884, a two-way valve 885, and a coolant reservoir 881. Piping connections and the coolant is not shown in the illustration.

[0036] The present disclosure does not intend to limit the type and quantity of components mentioned in the previous section. For example, the heat exchanger 884 may be either of an air cooled radiator, liquid to liquid heat exchanger, etc. Similarly, the pump 883, the valve 885, the heater 882, and the coolant reservoir 881 may be of different types.

[0037] If multiple battery pack systems 880 are used, these battery pack systems 880 may be thermally connected in series or parallel. But connecting the battery pack systems 880 in parallel gives an advantage of having equal battery pack system temperatures. One or more pumps 883, heaters 882, heat exchangers 884, valves 885 and reservoirs 881 may be connected in any possible combination; but, that would result in a less efficient system as compared to using single components. Moreover, the order of components may be different than illustrated.

[0038] The thermal management system 800 operates in accordance to the climate conditions. For example, if the outside temperature is higher than 40 degree Celsius, the battery cells inside the battery pack system 880 may be at higher temperature than the desired operating temperature. Thus, it becomes necessary to lower the battery cell temperature to a desired level before operation. The two-way valve 885 diverts the coolant flow through heat exchanger 884 and the heater 882 is switched off. Thus, the heat from battery cell in the battery pack system 880 is absorbed by the coolant and is discharged to the heat exchanger 884. Once the desired operating temperature of the battery cells is achieved, the battery pack system 880 is allowed to operate and the coolant continues to flow through the heat exchanger 884 to dissipate heat generated from the operation of battery pack system 880. The flow rate of the pump 883 is adjusted to maintain the desired operating temperature of the battery pack system 880.

[0039] The switching and control operations of the two-way valve 885, the heater 882, or the pump 883 may be controlled by a controller or may be manually set by an operator.

[0040] For example, if the outside temperature is lower than 10 degree Celsius, the battery cell inside the battery pack system 880 may be at lower temperature than the desired operating temperature. Thus, it becomes necessary to raise the battery cell temperature to a desired level before operation. The two-way valve 885 diverts the coolant flow to bypass the heat exchanger 884 and the heater 882 is switched on. The heating of the battery cells is obtained. Once the desired operating temperature is achieved, the heater 882 is switched off and the battery pack system 880 is allowed to operate. Now, the two-way valve 885 diverts the coolant flow through the heat exchanger 884 to dissipate heat generated from the operation of battery pack system 880. The flow rate of the pump 883 is adjusted to maintain the desired operating temperature of the battery pack system 880.

[0041] The battery pack system 880 of the present disclosure, provides an efficient and cost effective mechanism for thermal regulation. Moreover, the control method as disclosed in the foregoing description is comparatively less labor intensive, thereby reducing the power consumption.

[0042] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

[0043] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.