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) provided for coolant (160) to enter into the battery pack system (100), wherein the inlet (111) coupled to one or more coolant compartment (110); and
an outlet (112) provided for coolant (160) to exit from the battery pack system (100), wherein the outlet (112) coupled to the one or more coolant compartment (110);
a refrigerant tube (200) for circulation of refrigerant (161) from inlet (201) to outlet (202), wherein the refrigerant tube (200) is configured to cool the coolant (160);
at least one heat pipe (150), the heat pipe (150) has at least a portion immersed in the coolant compartment (110), wherein the coolant is in contact with the heat pipe (150);
a thermally conductive and electrically insulative (TCEI) material (170) configured to contact an outer wall of at least one heat pipe (150) and an outer wall of at least one of the battery cell (141);
wherein, the battery pack system (100) regulates the temperature of at least one battery cell (141) by circulating the coolant (160) such that the TCEI material (170) transfers the heat between the one or more battery cells (141) and the coolant through the one or more heat pipes (150).

2. 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.

3. 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.

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

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

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

7. The battery pack system (100) as claimed in claim 1, wherein more than one coolant compartments (110) are used.

, Description:BATTERY PACK TEMPERATURE REGULATION SYSTEM USING REFRIGERANT AND HEAT PIPES

FIELD OF INVENTION

[001] The present invention generally relates to a field of batteries. More specifically, the present invention relates to a battery pack system comprising a plurality of battery cells having a temperature regulation system.

BACKGROUND

[002] It is known that battery pack systems are widely used in various power storage devices, vehicles, and so on. The 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. Typically, the battery pack system includes multiple modules comprising plurality of battery cells. It is known that temperature has an influence over life and safety of the battery pack system. For power storage and electric vehicle applications, the battery pack system experiences high charge and discharge rates and the internal chemical reactions of the battery cell generates heat.

[004] Further, 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] In existing battery pack systems, battery cells are closely arranged in the battery modules to get maximum packing efficiency and are electrically connected in series or parallel. As a result, the battery pack system requires coolant flowing through external heat exchanger for maintaining the temperature of the battery pack system.

[006] Therefore, there is a need in the art to provide a thermal management system for a battery pack system for keeping 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.

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 order to overcome the problems discussed in the prior art, the present invention provides a battery pack system with internal heat exchanger to eliminate use of external heat exchanger and reducing the size of the overall thermal management system.

[009] Further, the present invention utilizes both internal and external heat exchangers to allow additional cooling of the battery pack in extreme hot conditions.

[0010] 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 coolant compartment, wherein the coolant compartment is coupled to an outlet provided for coolant exit from the battery pack system. Further, a refrigerant tube is provided inside the coolant compartment such that the refrigerant tube provides cooling to the coolant inside the coolant compartment. Furthermore, at least one heat pipe is provided which is in thermal contact with at least one battery cell through at least one thermally conductive and electrically insulative (TCEI) material, wherein at least a portion of the heat pipe is immersed inside the coolant compartment. The TCEI material is configured to contact an outer wall of at least one heat pipe and an outer wall of at least one of the battery cell such that the TCEI material transfers the heat between the one or more battery cells and the one or more heat pipes. The coolant absorbs or discharges the heat from or to one or more battery cells through a thermally conductive electrically insulative (TCEI) material.

[0011] 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.

[0012] The summary above is illustrative only and is not intended to be in any way limiting. Further aspects, exemplary embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF DRAWINGS

[0013] Embodiments of the disclosure will now be described, by way of example, with reference to the accompanying drawings, in which:

[0014] FIG. 1 illustrates a perspective view of the battery pack system, in accordance with one embodiment of the present invention.

[0015] FIG. 2 illustrates a perspective view of internal structure of the battery pack system shown in FIG. 1.

[0016] FIG. 3 illustrates a sectioned perspective view of the battery pack system in FIG. 1 emphasizing the coolant compartment.

[0017] FIG. 4 illustrates a sectioned perspective view of internal structure of the battery pack system shown in FIG.1 showing flow of coolant and refrigerant.

[0018] FIG. 5 illustrates the sectioned perspective view of the battery pack internal structure showing battery cell arrangement with heat pipes.

[0019] FIG. 6A illustrates a cross section view of the cylindrical battery cells in a triangular arrangement having a heat pipe with thermally conductive electrically insulative (TCEI) material on outer walls of heat pipe in accordance with the embodiment of the present invention.

[0020] FIG. 6B and C show cross section view of the cylindrical battery cells in a square arrangement having a heat pipe with TCEI material on outer walls of heat pipe in accordance with the embodiment of the present invention.

[0021] FIG. 6D illustrates a cross section view of the cylindrical battery cells in a hexagonal arrangement having a heat pipe with TCEI material on outer walls of heat pipe in accordance with the embodiment of the present invention.

[0022] 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

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] Embodiments of the present disclosure will be described below in detail with reference to the accompanying figures.

[0028] 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.

[0029] The present invention discloses a battery pack system with internal heat exchanger to eliminate use of external heat exchanger and reducing the size of the overall thermal management system. 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 coolant compartment, wherein the coolant compartment is coupled to an outlet provided for coolant exit from the battery pack system. Further, a refrigerant tube is provided inside the coolant compartment such that the refrigerant tube provides cooling to the coolant inside the coolant compartment. Furthermore, at least one heat pipe is provided which is in thermal contact with at least one battery cell through at least one thermally conductive and electrically insulative (TCEI) material, wherein at least a portion of the heat pipe is immersed inside the coolant compartment. The TCEI material is configured to contact an outer wall of at least one heat pipe and an outer wall of at least one of the battery cell such that the TCEI material transfers the heat between the one or more battery cells and the one or more heat pipes. The coolant absorbs or discharges the heat from or to one or more battery cells through a thermally conductive electrically insulative (TCEI) material.

[0030] Various embodiments of the battery pack system are explained using FIGS 1-6D.

[0031] Referring to FIG. 1, 2 and 3, a battery pack system 100 provided for the temperature regulation of the battery cells 141 is disclosed. Referring to FIG. 2 and FIG. 3, the battery pack system 100 of FIG. 1 comprising 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 structures 142 may be plates with provision of slots in which the battery cells 141 may be fit into. The battery casing 130 encloses and holds the battery modules 140 together. One or more such battery modules constitute the battery pack system 100.

[0032] 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.

[0033] The arrangement pattern of the battery cells 141 may be staggered or inline. Moreover, the battery cells structures may be provided 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.

[0034] Further, the battery pack system 100 comprises openings for coolant 160 to flow in and out of the battery pack system 100. 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 coolant compartment 110. As can be seen, the coolant compartment 110 is coupled to the coolant inlet 111. Further, the coolant compartment 110 is coupled to the coolant outlet 112.

[0035] The coolant compartment 110 is positioned at the top of battery pack system 100. However, it should be understood that the coolant compartment 110 may also be positioned at bottom of the battery pack system 100, and such implementation is within the scope of the present invention.

[0036] In one implementation, the battery pack system 100 comprises heat pipes 150 as shown in FIGS. 3, 4 and 5. Further, the heat pipes 150 may be used for the heat conduction between the battery cell 141 and the coolant 160 through a thermally conductive and electrically insulative (TCEI) material 170. It is to be noted that a “heat pipe” indicates a closed container in which a continuing cycle of evaporation and condensation of a fluid takes place with the heat being given off at the condenser end and which is more effective in transferring heat than a metallic conductor. As shown in the FIGS. 3, 4 and 5, at least a portion of the heat pipes 150 is immersed inside the coolant compartment 110, such that coolant 160 is in contact with the heat pipes 150. The heat pipes 150 shown for exemplary purpose in the embodiments are circular type of heat pipes. The heat pipes 150 are further in contact with the TCEI material 170. The TCEI material 170 thermally connects the heat pipes 150 to the battery cells 141. The TCEI material 170 prevents any electrical contact of the battery cells 141 with the heat pipes 150 while allowing the heat to be conducted between the battery cells 141 and the heat pipes 150. The TCEI material 170 may be silicone rubbers, thermal epoxies, thermal foam or other such materials known in the art.

[0037] Further, the battery pack system 100 comprises a refrigerant tube 200 as shown in FIGS 2, 3, and 4. The refrigerant tube 200 comprises an inlet 201 and an outlet 202 for flow of refrigerant 161 in and out of the refrigerant tube 200. The refrigerant tube 200 inside the coolant compartment 110 lowers the temperature of the coolant 160. The flow rate of refrigerant 161 may be monitored and controlled according to the cooling requirements by a controller.

[0038] The temperature of coolant 160 is lowered by the refrigerant tube 200. As can be seen from FIGS. 2, 3, and 4, the refrigerant tube 200 is provided in the battery pack system 100. The coolant 160 at lower temperature than battery cell 141 temperature is circulated for cooling the battery cell 141. Herein, the TCEI material 170 absorbs the heat from the battery cells 141 and discharges it to the heat pipes 150, further the heat from the heat pipes 150 is taken away from the coolant 160 at lower temperature inside the compartment 110. The heat absorbed from the coolant 160 may also be discharged to an external thermal management system. Similarly, when heating of the battery cell 141 is required, coolant having higher temperature than battery cell 141 is supplied. Herein, the TCEI material 170 discharges the heat to the battery cells 141 from the heat pipes 150, the heat pipes 150 are heated by the hot coolant at higher temperature. The amount of heat released from the coolant 160 may be gained again from an external thermal management system.

[0039] The battery cell 141 may be arranged in different arrangements along with the heat pipe 150 and TCEI material 170. Moreover, the geometries of the heat pipe 150 may be of any possible shape. Moreover, TCEI material 170 may be attached on outer walls of the outer tubes 150 or outer walls of the battery cells 141. Also, TCEI 170 may be of any possible shape as long as it facilitates heat conduction between the battery cells 141 and the heat pipes 150.

[0040] Referring to FIG. 6A-D, battery cells 141 arranged in different arrangements or configurations is shown, in accordance with exemplary embodiments of the present invention.

[0041] As illustrated in FIG. 6A, one arrangement of the battery cells 141 with heat pipe 150 and TCEI 170 is shown. The battery cells 141 are arranged in a triangular arrangement having a heat pipe 150 with TCEI material 170 on outer walls of heat pipe 150.

[0042] As illustrated in FIG. 6B, another arrangement of the battery cells 141 with heat pipe 150 and TCEI 170 is shown. The battery cells 141 are arranged in a square arrangement having a heat pipe 150 with TCEI material 170 on outer walls of heat pipe 150. As illustrated in FIG. 6C, yet another arrangement of the battery cells 141 with heat pipes 150 and TCEI material 170 is shown. The battery cells 141 are arranged in a square arrangement having a heat pipe 150 with TCEI material 170 on outer walls of the battery cell 141 is shown.

[0043] As illustrated in FIG. 6D, another arrangement of the battery cells 141 with heat pipe 150 and TCEI 170 is shown. The battery cells 141 are arranged in a hexagonal arrangement having a heat pipe 150 with TCEI material 170 on outer walls of heat pipe 150.

[0044] 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.

[0045] 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.