McDonald (45) Date of Patent: Oct. 7, (54) LITHIUM ION BATTERY COOLING SYSTEM (56) References Cited

Transcription

1 (12) United tate Patent U B2 (10) Patent No.: U 8,852,772 B2 McDonald (45) Date of Patent: Oct. 7, 2014 (54) LITHIUM ION BATTERY COOLING YTEM (56) Reference Cited COMPRIING DELECTRICFLUID U.. PATENT DOCUMENT (75) Inventor: tephen. McDonald, Hartland, MI (U) 4,007,315 A * 2/1977 Brinkmann et al / A1* 7/2001 Kawakami et al /49 (73) Aignee: GM Global Technology Operation R. R. R E, O..E LLC, Detroit, MI (U) 2009 OO68547 A1* 3, 2009 Ambroio et all 429/ , O A1* 6, 2009 Okada et al /120 (*) Notice: ubject to any diclaimer, the term of thi 2009/ A1* 10, 2009 Nemeh et al /117 patent i extended or adjuted under / A1* 10, 2009 Gaben U..C. 154(b) by 377 day. OTHER PUBLICATION (21) Appl. No.: 13/296,632 Cooling and Preheating of Batterie in Hybrid Electric Vehicle:, Ahmad Pearan, The 6th AME-JME Thermal Engineering Joint (22) Filed: Nov. 15, 2011 Conference, Mar , 2003, p Retrieved online on Mar. 18. (65) Prior Publication Data 2013 from: pdf/te W ap.pdf.* U 2013/O A1 May 16, 2013 (Continued) (51) Int. Cl. HIM I/02 ( ) Primary Examiner Kenneth Douyette HIM I/04 ( ) (74) Attorney, Agent, or Firm Fraer Clemen Martin & HIM IO/50 ( ) Miller LLC; J. Dougla Miller B60K L/00 ( ) B60K II/02 ( ) (57) ABTRACT HIM I/0525 ( ) A Lithium Ion battery cooling ytem for ue in a hybrid HIM IO/60 ( ) vehicle comprie a plurality of elf-contained liquid cooling B60L. II/I ( ) module, each cooling module including a cloed and ealed (52) U.. Cl. container having an interior pace. Each cooling module CPC... B60L 1 1/18 ( ); Y02T 10/701 1 include a battery aembly dipoed within the interior pace ( ). H0IM 10/0525 ( ); H0IM of the container and a plurality of battery cell having at leat I0/50 ( ); B60L II/1874 ( ); one fluid channel formed therebetween for receiving a fluid Y02T 10/7005 ( ); therein. A dielectric fluid i dipoed within the at leat one Y02T 10/705 ( ) fluid channel. The dielectric fluid ubtantially immere and UPC /72; 429/50: 429/90,429/120; i in contact with the battery aembly to heat and cool the 429/163; 180/65.1; 180/65.21: 123/41 battery aembly. A heating element i dipoed within the (58) Field of Claification earch interior pace and heat the dielectric fluid. A cooling element UPC /56, 120, 5, 72,90, 163, 50: 320/104; 180/65.28, 68.1, 65.1, 65.21; 123/41 ee application file for complete earch hitory. i dipoed within the interior pace and cool the dielectric fluid. 20 Claim, 2 Drawing heet 4. on 146 (" A8 A. -A-A-N A -N9 - A-7-9-1N->> -- A. ZZ -N. A fig 2 30 in A Y/ 3. A. t y 7 / ty- f EN ft.

2 U 8,852,772 B2 Page 2 (56) Reference Cited OTHER PUBLICATION For Electric Car Batterie, Managing Hot and Cold I Jut Right'. Richard Cooke, Matternetwork.com, ep. 9, Retrieved online on Mar. 19, 2013 from: tric-car-batterie-managing-hot.cfm. Ford Ue Innovative Liquid-Cooled Battery ytem to Help Focu Electric Owner Maximize Range'. Ford Motor Company Publica tion, ep. 2, Retrieved online on Mar. 19, 2013 from: media.ford.com/article diplay.cfm?article id=33185.* "econd Law Analyi of a Liquid Cooled Battery Thermal Manage ment ytem for Hybrid and Electric Vehicle. Lokendra Ramotar, Thei p , Univerity of Ontario Intitute of Technology, Aug Retrieved online on Mar. 19, 2013 from: library.dc uoit.ca/bittream/10155/111/1/ramotar Lokendra.pdf.* Ramotar, Lokendra, econd Law Analyi of a Liquid Cooled Battery Thermal Management ytem for Hybrid and Electric Vehicle, Uni verity of Ontario Intitute of Technology, Aug. 2010, pp * cited by examiner

3 U.. Patent U 8,852,772 B2

4 U.. Patent Oct. 7, 2014 heet 2 of 2 U 8,852,772 B2 N N... N (C

5 1. LITHIUM ION BATTERY COOLING YTEM COMPRIING DELECTRICFLUID FIELD OF THE INVENTION The preent dicloure relate to a vehicle battery pack with a elf-contained liquid cooling ytem. BACKGROUND OF THE DICLOURE A battery cell ha been propoed a a clean, efficient and environmentally reponible power ource for electric vehicle and variou other application. One type of battery cell i known a the lithium-ion battery. The lithium-ion bat tery i rechargeable and can be formed into a wide variety of hape and ize o a to efficiently fill available pace in electric vehicle. For example, the battery cell may be pri matic in hape to facilitate a tacking of the battery cell. A plurality of individual battery cell can be provided in a bat tery pack to provide an amount of power ufficient to operate electric vehicle. Typical primatic battery cell have a pair of platic coated metal layer fued around a periphery of the battery cell in order to eal the battery cell component. The ealing of the battery cell generally begin with providing one of the pla tic coated metal layer with a cavity, ometime called a butterdih' hape. The battery cell component are dipoed inide the cavity of the platic coated metal layer. The other of the platic coated metal layer i then placed on top of the battery cell component and fued at the periphery to the one of the platic coated metal layer with the cavity, for example, by heat ealing around the edge. The battery cell for incor poration in a battery packaembly i thereby provided. Battery cell uch a lithium-ion battery cell are known to generate heat during operation and a a reult of a charge cycle when recharging. When overheated or otherwie expoed to high-temperature environment, undeirable effect can impact the operation of lithium-ion batterie. Cooling ytem are typically employed with lithium-ion battery pack to militate againt the undeirable overheating condition. The cooling ytem may include cooling plate or fin andwiched between individual battery cell within the battery pack. The cooling ytem may have channel through which a coolant flow in a heat tranfer relationhip with the battery cell. Nonlimiting example of known cooling y tem for battery cell are decribed in Aignee' co-pending U.. patent application er. No. 12/713,729 to Einger et al. and U.. patent application er. No. 12/842,478 to Kumar et al., the entire dicloure of which are hereby incorporated herein by reference. Conventional cooling ytem have included air to air cool ing, cooling plate or fin andwiched between individual battery cell within the battery pack along with heat ink in the ame location. There i a continuing need for a battery cooling ytem and a method for making the battery cooling ytem that maxi mize efficient heating and cooling of the battery cell with minimum delta temperature. Deirably, the battery cooling ytem and method maintain uniform urface temperature over the battery cell and efficiently tranfer heat away from the cell uing open bath cooling in a hybrid vehicle. UMMARY OF THE INVENTION In concordance with the intant dicloure, a battery cool ing ytem and method of cooling a battery pack i urpri ingly dicovered. In a firt embodiment, a vehicle battery U 8,852,772 B pack with a elf-contained liquid cooling ytem comprie a ealed container having an interior pace; a battery aembly dipoed within the interior pace of the container, the battery aembly including a plurality of battery cell having at leat one fluid channel formed therebetween; a dielectric fluid dipoed within the at leat one fluid channel in contact with the battery cell of the battery aembly and configured to heat and cool the battery aembly; a heating element di poed within the interior pace configured to heat the dielec tric fluid; and a cooling element dipoed within the interior pace configured to cool the dielectric fluid. In another embodiment, a Lithium Ion battery cooling ytem for ue in a hybrid vehicle comprie a plurality of elf-contained liquid cooling module, each of the cooling module further comprie a ealed container having an inte rior pace; a battery aembly dipoed within the interior pace of the container and including a plurality of battery cell having at leat one fluid channel formed therebetween; a dielectric fluid dipoed within the at leat one fluid channel in contact with the battery cell of the battery aembly and configured to heat and cool the battery aembly; a heating element dipoed within the interior pace configured to heat the dielectric fluid; and a cooling element dipoed within the interior pace configured to cool the dielectric fluid. In a further embodiment, a method of cooling a vehicle battery pack comprie the tep of providing a ealed con tainer having an interior pace; providing a battery aembly within the interior pace of the container and including a plurality of battery cell having at leat one fluid channel formed therebetween; providing a dielectric fluid within the interior pace; immering at leat a portion of the battery aembly with the dielectric fluid; cauing the dielectric fluid to flow about the plurality of battery cell throughout the interior pace of the container, and cooling the dielectric fluid during operation of the vehicle to maintain a ubtantially uniform urface temperature over each of the plurality battery cell. DRAWING The above, a well a other advantage of the preent dicloure, will become readily apparent to thoe killed in the art from the following detailed decription, particularly when conidered in the light of the drawing decribed herein. FIG. 1 i a chematic view of the battery cooling ytem of the preent dicloure; and FIG. 2 i a plan view of multiple battery cooling ytem of the preent invention connected in erie. DETAILED DECRIPTION OF THE INVENTION The following detailed decription and appended drawing decribe and illutrate an embodiment of the invention. The decription and the drawing erve to enable one killed in the art to make and ue the invention, and are not intended to limit the cope of the invention in any manner. In repect of the method dicloed, the tep preented are exemplary in nature, and thu, the order of the tep i not neceary or critical. With reference to FIG. 1, a vehicle battery pack with a elf-contained liquid cooling ytem 10 of the preent diclo ure i there hown. The ytem 10 i a module 12 formed of a container 14 with an interior pace 16 for upporting a battery aembly 18. The container 14 i a cloed and ealed container 14 for forming a elf-contained liquid cooling y tem 10. In one embodiment, the battery aembly 18 include a plurality of battery cell 20 uch a a plurality of Lithium

6 3 ion (Li-ion) batterie for ue in a hybrid vehicle. In another embodiment, the plurality of battery cell 20 i Li-ion batter ie for ue in a Battery Electric Vehicle (BEV). Additional batterie for ue with other prime mover vehicle may be provided with the liquid cooling ytem 10 of the preent invention, where each battery cell include active material for generating power from an electrochemical reaction within the interior pace 16 of the container 14. The battery cell 20 are preferably tacked to form a battery cell tack 22. In the embodiment hown, a gap 24 between each battery cell 20 i between mm, forming a fluid channel 26 between each battery cell 20. In another embodiment, the gap 24 may be le than 0.25 mm. It i undertood that other gap ize can be ued a deired. A dielectric coolant 28 i dipoed within the interior pace 16 of the container 14 and the fluid level hown i uch that the battery aembly 18 i completely immered within the dielectric coolant 28. The dielectric coolant 28 i in contact with the battery cell 20 through the fluid channel 26 formed by gap 24. In one embodiment, the dielectric coolant 28 may be halogenated. In another embodiment, the dielectric cool ant 28 may be conditioned to have a boiling point at or near a deired operating temperature of the battery cell 20. A heating element 34 i located at a bae area 36 of the container 14. The heating element 34 hown i an electronic heating element. It i undertood that other heating element type may be ued. The heating element 34 i hown a a ingle element; however, multiple heating element 34 uch a heating plate may be provided. A cooling element 38 i located at an upper area 40 of the container 14. The cooling element 38 may be a chilled water condener having an inlet 42 and an outlet 44 extending beyond the wall of the ealed container 14 for importing and exporting water for the cooling element 38. In another embodiment, the cooling element 38 may be a chilled water plate. In till another embodiment, the cooling element 38 may be a thin aluminum heat ink having external chilled water travelling through the cooling element 38. The cooling element 38 may be a graphite foil impregnated with an elec trically nonconductive polymer. The cooling element may alo be formed from copper. In the embodiment hown, arrow 'A' and B indicate a flow of the dielectric coolant 28. Upon heating of each battery cell 20 by the heating element 34, the dielectric coolant 28 expoed to a front urface area 30 and a rear urface area 32 of the battery cell 20, will boil. The heated dielectric coolant 28 will rie and flow to the top of the battery cell tack 22 to be cooled by the cooling element 38. The cooled dielectric cool ant 28 will return to the bae area 36, generally following either coolant path 'A' or B Where the general location of the dielectric coolant 28 at the moment of boiling i located within the fluid channel 26 of the battery cell 20 in the center area and toward a ide 50 of the container 14, the dielectric coolant 28 will tend to follow flow path 'A'. imi larly, if the general location of the dielectric coolant 28 at the moment of boiling i located within the fluid channel 26 of the battery cell 20 in the center area and toward an oppoing ide 52 of the container 14, the dielectric coolant 28 will tend to follow flow path B. A coolant temperature enor 46 i located on or near the cooling element 38. In the embodiment hown, the tempera ture enor 46 i located within the area of the outlet 44 of the cooling element 38 and meaure a temperature of the dielec tric coolant 28 at a point of expoure to the cooling element. The temperature enor 46 may be located anywhere within the battery cell tack 22 a deired. U 8,852,772 B A coolant level enor 48 i alo provided and i located near the upper area 40 of the container 14 to meaure the fluid level of the dielectric coolant 28 within the container 14, enuring complete immerion of the battery aembly 18 within the dielectric coolant 28. FIG. 2 illutrate a plurality of elf-contained liquid cool ing module 12 connected in erie via a conduit 60 and forming a cooling ytem 100 for ue in a hybrid vehicle or BEV. In one embodiment, the inlet 42 of the cooling element 38 for each module 12 i in fluid communication with the vehicle' air conditioning (A/C) ytem 120 by a conduit 70. In turn, the heat generated from each cooling module 12 may be expelled through the outlet 44 to the coolant 130 by a conduit 80. The coolant 130 provide an external heat exchange with the vehicle, where the vehicle i a hybrid vehicle. Alternatively, the heat generated from each cooling module 12 may be expelled through the outlet 44 and the conduit 80 to the coolant 130, uch a an electronic cooling loop, where the prime mover i a BEV, typically through a valve, uch a a 3-way valve 140. The preent dicloure further include a method of cool ing a vehicle battery pack. The method include the tep of providing a cloed and ealed container 14. The container 14 ha an interior pace 16. A battery aembly 18 i dipoed within the interior pace 16 of the container 14. The battery aembly 18 include a plurality of battery cell 20 having fluid channel 26 formed between the tacked cell 20. The tacked cell 20 maintain a gap 24 between battery cell 20 of no greater than 0.50 mm and no le than 0.25 mm in one embodiment. In another embodiment, the gap 24 may be le than 0.25 mm. Each gap 24 form the fluid channel 26 between adjacent battery cell 20. A dielectric coolant 28 i dipoed within the interior pace 16 of the container 14. The battery aembly 18 typically i fully immered within the dielectric coolant 28 and the dielectric coolant 28 i received within the fluid channel 26, completely contacting each of the battery cell 20. By filling the gap 24 with the dielectric coolant 28, both heating and cooling can be accomplihed. During tart up of a vehicle, a heating element 34 located along the bae area 36 of the container 14 may heat the dielectric fluid 28 to boiling. In one embodiment, the dielec tric fluid 28 may be conditioned to have a boiling point at or near the deired operating temperature of the battery cell 20. Vapor rie between the fluid channel 26, heating the battery cell 20 to the operating temperature. Condenation heating enure efficient and uniform temperature heat tranfer with out overhoot of the battery cell 20 temperature. When the battery cell 20 are operating, the dielectric coolant 28 boil on the urface of the battery cell 20, keeping temperature of the urface uniform and tranferring heat efficiently to the cooling element 38. The heated coolant 28 rie, traveling through the fluid channel 26 from the bae area 36 of the container 14 to the upper area 40, fully flowing acro each battery cell 20 throughout the interior pace 16 of the con tainer 14 a illutrated by arrow A and B. The cooled dielectric coolant 28 will return to the bae area 36, generally following either coolant path A or B Where the general location of the dielectric coolant 28 at the moment of boiling i located within the fluid channel 26 of the battery cell 20 in the center area and toward a ide 50 of the battery cell tack 22, the dielectric coolant 28 will tend to follow flow path 'A'. imilarly, if the general location of the dielectric coolant 28 at the moment of boiling i located within the fluid channel 26 of the battery cell 20 in the center area and toward an oppo ing ide 52 of the battery cell tack 22, the dielectric coolant 28 will tend to follow flow path B. During operation, the coolant 28 flowing along the fluid channel 26 provide a

7 5 ubtantially uniform urface temperature over each of the plurality of battery cell 20 while tranferring heat away from each of the battery cell 20 by the flowing dielectric coolant 28. The tep of condening the vapor include the ue of the cooling element 38, uch a a chilled water plate, placed above the battery cell 20 in the upper area 40 of the container 14. Multiple battery cell 20 form multiple module 12. The module 12 are connected in erie. The heated vapor rie to the upper area 40 of the container and are cooled by the cooling element 38. The water within the cooling element 38 i chilled by an exiting air conditioning ytem chiller of the vehicle and circulated from the inlet 42 to the outlet 44 of the cooling element 38. A coolant temperature enor 46 mea ure the dielectric coolant 28 temperature at the outlet 44 of the cooling element 38. A coolant level enor 48 meaure the level of the dielectric coolant 28 within the container 14. While certain repreentative embodiment and detail have been hown for purpoe of illutrating the invention, it will be apparent to thoe killed in the art that variou change may be made without departing from the cope of the diclo ure, which i further decribed in the following appended claim. What i claimed i: 1. A vehicle battery pack with a elf-contained liquid cool ing ytem compriing: a ealed container having an interior pace; a battery aembly dipoed within the interior pace of the container, the battery aembly including a plurality of battery cell having at leat one fluid channel formed therebetween: a dielectric fluid dipoed within the at leat one fluid channel in contact with the battery cell of the battery aembly and configured to heat and cool the battery aembly; a heating element dipoed within the interior pace con figured to heat the dielectric fluid; and a cooling element dipoed within the interior pace con figured to cool the dielectric fluid. 2. The vehicle battery pack of claim 1, wherein the at leat one fluid channel i configured to direct the dielectric fluid through the plurality of battery cell in the interior pace of the container. 3. The vehicle battery pack of claim 1, wherein the battery cell of the battery aembly are completely immered in the dielectric fluid. 4. The vehicle battery pack of claim 1, wherein the dielec tric fluid i configured to have a deired boiling point. 5. The vehicle battery pack of claim 1, wherein the cooling element i one of a metal plate and a graphite foil impregnated with an electrically nonconductive polymer. 6. The vehicle battery pack of claim 1, wherein the cooling element i formed from one of copper and aluminum. 7. The vehicle battery pack of claim 1, wherein the cooling element i dipoed above the battery cell. 8. The vehicle battery pack of claim 1, wherein the heating element i dipoed below the battery cell. 9. The vehicle battery pack of claim 1, further compriing at leat one of a dielectric fluid temperature enor and a dielectric fluid level enor dipoed within the container. 10. A Lithium Ion battery cooling ytem foruein a hybrid vehicle compriing: a plurality of elf-contained liquid cooling module, each of the cooling module further compriing: U 8,852,772 B a ealed container having an interior pace; a battery aembly dipoed within the interior pace of the container and including a plurality of battery cell having at leat one fluid channel formed therebe tween; a dielectric fluid dipoed within the at leat one fluid channel in contact with the battery cell of the battery aembly and configured to heat and cool the battery aembly; a heating element dipoed within the interior pace configured to heat the dielectric fluid; and a cooling element dipoed within the interior pace configured to cool the dielectric fluid. 11. The Lithium Ion battery cooling ytem of claim 10, wherein the at leat one fluid channel i configured to direct the dielectric fluid through the plurality of battery cell in the interior pace of the container. 12. The Lithium Ion battery cooling ytem of claim 10, wherein the battery cell of the battery aembly are com pletely immered in the dielectric fluid. 13. The Lithium Ion battery cooling ytem of claim 10, wherein the dielectric fluid i configured to have a deired boiling point. 14. The Lithium Ion battery cooling ytem of claim 10, wherein the cooling element i one of a metal plate and a graphite foil impregnated with an electrically nonconductive polymer. 15. The Lithium Ion battery cooling ytem of claim 10, wherein the cooling element i formed from one of copper and aluminum. 16. The Lithium Ion battery cooling ytem of claim 10, wherein the cooling element i dipoed above the battery cell. 17. The Lithium Ion battery cooling ytem of claim 10, wherein the heating element i dipoed below the battery cell. 18. The Lithium Ion battery cooling ytem of claim 10, further compriing at leat one of a dielectric fluid tempera ture enor and a dielectric fluid level enor dipoed within the container. 19. A method of cooling a vehicle battery pack compriing the tep of: providing a ealed container having an interior pace: providing a battery aembly within the interior pace of the container and including a plurality of battery cell having at leat one fluid channel formed therebetween: providing a dielectric fluid within the interior pace: immering at leat a portion of the battery aembly with the dielectric fluid; cauing the dielectric fluid to flow about the plurality of battery cell throughout the interior pace of the con tainer; heating the dielectric fluid during tart up of the vehicle to heat the plurality of battery cell, wherein a heating element dipoed within the interior pace of the ealed container i ued to cool the dielectric fluid; and cooling the dielectric fluid during operation of the vehicle to maintain a ubtantially uniform urface temperature over each of the plurality battery cell, wherein a cooling element dipoed within the interior pace of the ealed con tainer i ued to cool the dielectric fluid. 20. The method of cooling a vehicle battery pack of claim 19, wherein the battery cell of the battery aembly are completely immered in the dielectric fluid. ck k k k k