Method of cooling a battery pack using flat heat pipes

• US 8,231,996 B2
• Filed: 02/17/2009
• Issued: 07/31/2012
• Est. Priority Date: 02/15/2008
• Status: Active Grant

• Current Assignee: Atieva, Inc.
• Original Assignee: Atieva USA, Inc.
• Inventors: Howard, Keith, Lin, Sheau-Pyng
• Primary Examiner(s): Wang, Eugenia
• Application Number:
  US12/372,693
• Publication Number:
  US 20090208829A1
• Time in Patent Office: 1,260 Days
• Field of Search: 429/120
• US Class Current: 429/120
• CPC Class Codes: F28D 15/0233 the conduits having a particular shape, e.g. non-circular cross-section, annular F28D15/0241, F28D15/0266 take precedence
• CPC Class Codes: F28D 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/617 for achieving uniformity or desired distribution of temperature
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/643 Cylindrical cells
• CPC Class Codes: H01M 10/651 characterised by parameters specified by a numeric value or mathematical formula, e.g. ratios, sizes or concentrations
• CPC Class Codes: H01M 10/6552 Closed pipes transferring heat by thermal conductivity or phase transition, e.g. heat pipes
• CPC Class Codes: H01M 10/6556 Solid parts with flow channel passages or pipes for heat exchange closed pipes H01M10/6552
• CPC Class Codes: H01M 10/6567 Liquids
• CPC Class Codes: H01M 6/42 Grouping of primary cells into batteries H01M6/40 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Methods of cooling a battery pack comprising a large number of cells are disclosed in various embodiments. In one embodiment, one or more low thermal resistance heat pipes are used to transfer heat away from the battery pack. In another embodiment, the heat pipes are coupled to a cold plate cooled by circulating liquid.

Claims

1. A battery pack comprising:

a plurality of battery cells each having a cylindrical housing with an anode at one end of the housing;

a conducting plate disposed to make electrical contact with the plurality of battery cells;

a first thermal interface material disposed between an anode end of each of the battery cells and the conducting plate to achieve thermal contact between the conducting plate and the plurality of battery cells such that the conducting plate provides thermal spreading to reduce temperature differences between individual battery cells of the plurality of battery cells;

a sealed heat pipe containing a fluid that exists partially in a liquid phase and partially in a gaseous phase, the heat pipe having an evaporation section from which the liquid phase fluid evaporates and a condensation section from which the gaseous phase fluid condenses, the heat pipe further having (i) first and second flat surfaces disposed in thermal contact with first and second subsets of the battery cells, respectively, and (ii) a third flat surface adjacent the evaporation section; and

a second thermal interface material disposed between the conducting plate and the third flat surface of the heat pipe to achieve thermal contact between the evaporation section of the heat pipe and the conducting plate.

2. The battery pack of claim 1 wherein the first thermal interface material is electrically conducting.

3. The battery pack of claim 2 wherein the second thermal interface material is electrically insulating.

4. The battery pack of claim 1 further comprising a cold plate in thermal contact with the condensation section of the heat pipe, wherein the cold plate is cooled by liquid circulation.

5. The apparatus of claim 4 wherein a third thermal interface material is disposed between the condensation section of the heat pipe and the cold plate.

6. The battery pack of claim 1 wherein each of the battery cells has a side wall substantially orthogonal to its anode end, and wherein the first flat surface of the heat pipe is disposed substantially parallel to respective side walls of battery cells of the first subset of the battery cells.