Nested heatsink housing for lithium ion cells

A cell housing includes a first half section having a longitudinal side having a first end and a second end. A first lateral side extends perpendicularly to the longitudinal side from the first end. The first lateral side has a first tongue. A second lateral side extends perpendicularly to the longitudinal side from the second end. The second lateral side has a first groove. A second half section is identical to the first half section. The first and second half sections are coupled to each other such that the first tongue of the first half section is inserted into the first groove of the second half section and the first tongue of the second half section is inserted into the first groove of the first half section, forming a closed perimeter.

FIELD OF INVENTION

The present invention relates to housings that may be used to contain a battery cell therein. A plurality of the housings with their respective battery cells may be stacked together to form a battery.

BACKGROUND

Lithium ion batteries commonly employ metal heat sink and structural components as parts of a stacked battery assembly. These components are assembled from formed sheet metal components, which are inserted between individual battery cells. The battery cells and the interlayered sheet metal components are held together with metal or plastic bands. Spacing of the assembly relies on the thickness of the cells and is not well controlled, leading to inconsistencies in the manufacture of the batteries and reduced cell performance.

There exists a need to provide a more accurate mechanical spacing of heat sink surfaces.

SUMMARY

Briefly, the present invention provides an apparatus comprising a first half section including a first longitudinal side and a first lateral side extending perpendicularly from the first longitudinal side. The first lateral side has a first tongue. The first tongue has a first tongue lip extending toward the first longitudinal side. A second half section comprises a second longitudinal side and a second lateral side extending perpendicularly from the second longitudinal side. The second lateral side has a first groove. The first groove has a first groove lip extending toward the second longitudinal side. The first and second half sections are coupled to each other such that the first tongue of the first half section is inserted into the first groove of the second half section, forming a closed perimeter. A first clip is disposed over the first tongue lip of the first half section and the first groove lip of the second half section. The first clip secures the first and second half sections to each other.

Further, the present invention provides a method of manufacturing a cell comprising the steps of disposing an electrical cell between a first half section of a cell housing and a second half section of the cell housing, the second half section being identical to the first half section. The first half section comprises a longitudinal side having a first end and a second end and a first lateral side extending perpendicularly to the longitudinal side from the first end. The first lateral side has a first tongue. The first tongue has a first tongue lip extending toward the longitudinal side. A second lateral side extends perpendicularly to the longitudinal side from the second end. The second lateral side has a first groove. The first groove has a first groove lip extending toward the longitudinal side. The method further comprises the steps of engaging the first tongue of the first half section with the first groove of the second half section and the first tongue of the second half section with the first groove of the first half section; applying an even pressure along the longitudinal side of the first and second half sections; and securing the first and second half sections to each other.

Additionally, the present invention provides a cell housing comprising a first half section including a longitudinal wall having a first end and a second end and a first lateral wall extending perpendicular to the first longitudinal wall from the first end. The first lateral wall has a tongue at a free end thereof. A second lateral wall extends parallel to the first lateral wall from the second end. The second lateral wall has a groove at a free end thereof. A second half section is identical to the first half section. A tongue of the second half section is inserted into the groove of the first half section and the tongue of the first half section is inserted into a groove of the second half section. A first clip secures the first half section to the second half section at the free end of the first lateral wall. A second clip secures the first half section to the second half section at the free end of the second lateral wall.

DETAILED DESCRIPTION OF THE INVENTION

In describing the embodiments of the invention illustrated in the drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, it being understood that each specific term includes all technical equivalents operating in similar manner to accomplish similar purpose. It is understood that the drawings are not drawn exactly to scale. In the drawings, similar reference numbers are used for designating similar elements throughout the several figures.

The following describes particular embodiments of the present invention. It should be understood, however, that the invention is not limited to the embodiments detailed herein. As used herein, the term “hermaphroditic” means a device that has both male and female portions wherein the male portion is insertable into the female portions such as, for example, a tongue-and-groove arrangement.

With reference made to the figures, an exemplary embodiment of the present invention is a cell housing100for a large-format Lithium-ion (“Li-ion”) cell. Cell housing100is made of a pair of approximately squared-off “U” shaped first and second half sections102,202that are interlockable with each other. In an exemplary embodiment, first and second half sections102,202are identical hermaphroditic sections that are interlockable when second half section202is rotated by 180 degrees compared to first half section102. A cell101is located within the space defined by interlocked hermaphroditic half sections102,202.

First and second half sections102,202, respectively, may be constructed from a metal extrusion, such as, for example, aluminum. For numbering purposes only, because second half section202is identical to first half section102, elements2xxof second half section202have the same last two digits as respective elements1xxin first half section102.

Referring specifically toFIGS. 1-3, first half section102includes a longitudinal side110having a first end112and a second end114. A plurality of heat dissipating fins115extend outwardly from longitudinal side110. Heat dissipating fins115serve the purposes of dissipating heat away from cell housing100, as well as providing spacing between adjacent cell housings100, as will be discussed in more detail later herein.

A first lateral side116extends perpendicularly to longitudinal side110from first end112. First lateral side116has a first tongue118. First tongue118has a first tongue lip120extending toward longitudinal side110. First lateral side116also has at least one heat dissipating fin122extending outwardly therefrom.

A second lateral side130extends perpendicularly to longitudinal side110from second end114. Second lateral side130has a first groove132. First groove has a first groove lip134extending toward longitudinal side110. Second lateral side130also has at least one heat dissipating fin136extending outwardly therefrom.

First half section102further includes a second groove140extending parallel to first lateral side116at an intersection of longitudinal side110and first lateral side116. Second groove140comprises a second groove lip142. A second tongue144extends parallel to second lateral side130at an intersection of longitudinal side110and second lateral side130. Second tongue144comprises a second tongue lip146. In an exemplary embodiment, the length of second tongue144is the same length as that of heat dissipating fins115.

First and second half sections102,202, respectively, may be coupled to each other such that first tongue118of first half section102is inserted into first groove232of second half section202and first tongue218of second half section202is inserted into first groove132of first half section102, forming a closed perimeter.

Referring still toFIGS. 1-3, as well as to the flow chart500illustrated inFIG. 4, to form a cell using cell housing100, battery cell101is placed on a base162. In step502, half sections102,202are disposed around battery cell101and base162.

In step504, first tongue118of first half section102is engaged with first groove232of second half section202and first tongue218of second half section202is engaged with first groove132of first half section102.

In step506, an even pressure P is applied to longitudinal sides110,210, respectively, of both half sections102,202as shown inFIG. 1. This even pressure results in an even pressure being applied to battery cell101, which provides an even contact force between adjacent electrodes and separators (not shown) that make up battery cell101. This even contact force provides for an even distribution of the current generated by battery cell101, resulting improved performance and longer life of battery cell101compared to prior art battery cells.

In step508, as the pressure P is applied, first and second half sections102,202, respectively, are secured to each other. In an exemplary embodiment of the presenting invention, to secure first and second half sections102,202to each other, a first clip150may be disposed over first tongue lip120of first half section102and first groove lip234of second half section202such that first clip150couples first and second half sections102,202, respectively, to each other. First clip150may be a generally “C-shaped” clip that is symmetric about a centerline, so that first clip150may couple first and second half sections102,202, respectively, to each other in one of two orientations.

A second clip152, identical to first clip150, may similarly be disposed over a first tongue lip220of second half section202and first groove lip134of first half section102such that second clip152couples first and second half sections102,202, respectively, to each other.

After battery cell101and base162are secured within first and second half sections102,202, a battery cell lid164is placed over battery cell101. A lip166of lid164extends over longitudinal sides110,210and lateral sides116,130,216,230. Lid164is secured to battery cell101by nuts168,170. Lid164prevents clips150,152from being slid upward and off cell housing100.

Referring now toFIGS. 5 and 6, a plurality of cell housings100,100′ may be coupled together to form a multi-cell battery200. For numbering purposes only, because a second cell housing100′ is identical to cell housing100, elements1xx′ and2xx′ of cell housing100′ have the same digits as respective elements1xxand2xxin first cell housing100, but with a “′” (“prime”) at the end of the element in cell housing100′. For example, first half section102is identical to a third half section102′ and second half section202is identical to a fourth half section202′, with third and fourth half sections102′ and202′ making up second cell housing100′.

A tongue144′ of second cell housing100′ is inserted into a groove240of cell housing100and tongue244of cell housing100is inserted into a groove140′ of second cell housing100′ to couple cell housing100to cell housing100′, forming multi-cell battery200.

Third and fourth clips154,156, respectively, may be used to couple cell housings100,100′ to each other. Third clip154slides over the tongue and groove connections of tongue144′ and groove240, while fourth clip156slides over the tongue and groove connections of tongue244and groove140′.

Several of the heat dissipating fins215of cell housing100engage the longitudinal side110′ of second cell housing100′ and several of the heat dissipating fins115′ of second cell housing100′ engage the longitudinal side210of first cell housing100such that a plurality of voids160are formed between cell housing100and second cell housing100′. These voids allow for air flow between cell housing100and second cell housing100′ and help to dissipate heat generated within cell housing100and second cell housing100′ by their respective battery cells101,201.

While only two cell housings100,100′ are shown being coupled to each other, those skilled in the art will recognize that additional cell housings may be similarly coupled to cell housings100,100′ as desired.

While the principles of the invention have been described above in connection with preferred embodiments, it is to be clearly understood that this description is made only by way of example and not as a limitation of the scope of the invention.