Abstract:
Electrified vehicles such as hybrid electric vehicles (HEV&#39;s), plug-in hybrid electric vehicles (PHEV&#39;s), battery electric vehicles (BEV&#39;s), or fuel cell vehicles differ from conventional motor vehicles in that they are powered by one or more electric machines (i.e., electric motors and/or generators) instead of or in addition to an internal combustion engine. High voltage current for powering these types of electric machines is typically supplied by a high voltage traction battery system having one or more battery cells that store energy.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to an electrified vehicle, and more particularly, but not exclusively, to a battery cell spacer or separator for separating adjacent battery cells of a battery module. 
       BACKGROUND 
       [0002]    Electrified vehicles such as hybrid electric vehicles (HEV&#39;s), plug-in hybrid electric vehicles (PHEV&#39;s), battery electric vehicles (BEV&#39;s), or fuel cell vehicles differ from conventional engine vehicles in that they are powered by one or more electric machines (i.e., electric motors and/or generators) instead of or in addition to an internal combustion engine. High voltage current for powering these types of electric machines is typically supplied by a high voltage traction battery system having one or more battery cells that store energy. 
         [0003]    Electrified vehicle battery systems often include one or more battery modules. Each battery module includes a plurality of battery cells and a plurality of discrete battery cell spacers that are arranged between each adjacent pair of battery cells of the battery module. For example, the battery cells and battery cell spacers are often stacked side-by-side in an alternating fashion in order to physically separate the neighboring cells from one another. The battery cell spacers may additionally facilitate cell cooling and isolation from other conductive surfaces. 
       SUMMARY 
       [0004]    A battery cell spacer according to an exemplary aspect of the present disclosure includes, among other things, a unitary body including at least a first dividing wall and a second dividing wall spaced from the first dividing wall and a pocket defined between the first dividing wall and the second dividing wall. The unitary body is adjustable between a first position and a second position to change a dimension associated with the pocket. 
         [0005]    In a further non-limiting embodiment of the foregoing battery cell spacer, the first dividing wall and the second dividing wall are parallel to one another. 
         [0006]    In a further non-limiting embodiment of either of the foregoing battery cell spacers, a battery cell is received in the pocket. 
         [0007]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, an array structure is attached to at least one end of the unitary body. 
         [0008]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, the unitary body includes a plurality of walls and a plurality of pockets defined between adjacent walls of the plurality of walls. 
         [0009]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, the unitary body includes an accordion shape. 
         [0010]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, an end wall connects the first dividing wall and the second dividing wall. 
         [0011]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, the end wall includes a living hinge. 
         [0012]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, a hinged wall connects the first dividing wall and the second dividing wall. 
         [0013]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, at least one of the first dividing wall and the second dividing wall includes a flap that is movable between a first position and a second position to close off a bottom of the pocket. 
         [0014]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, the flap is connected to either the first dividing wall or the second dividing wall with a hinge. 
         [0015]    In a further non-limiting embodiment of any of the foregoing battery cell spacers, the first dividing wall includes a first flap and the second dividing wall includes a second flap that extends toward the first flap, the first flap and the second flap engageable to one another to close off a bottom of the pocket. 
         [0016]    A battery module according to another exemplary aspect of the present disclosure includes, among other things, a battery cell and a battery cell spacer that defines a pocket for receiving the battery cell, the battery cell spacer adjustable between an expanded position and a collapsed position to change a positioning of the battery cell spacer relative to the battery cell. 
         [0017]    In a further non-limiting embodiment of the foregoing battery module, the battery cell spacer includes a first dividing wall, a second dividing wall parallel to the first dividing wall, the pocket defined between the first dividing wall and the second dividing wall for accommodating the battery cell. 
         [0018]    In a further non-limiting embodiment of either of the foregoing battery modules, an end wall connects between the first dividing wall and the second dividing wall. 
         [0019]    In a further non-limiting embodiment of any of the foregoing battery modules, the pocket includes a first dimension in the expanded position and a second, smaller dimension in the collapsed position. 
         [0020]    A method according to another exemplary aspect of the present disclosure includes, among other things, positioning a battery cell in a pocket of a battery cell spacer and compressing the battery cell spacer to collapse the battery cell spacer about the battery cell. 
         [0021]    In a further non-limiting embodiment of the foregoing method, the step of compressing includes applying a force to at least one array structure. 
         [0022]    In a further non-limiting embodiment of either of the foregoing methods, the step of compressing includes adjusting a molded body of the battery cell spacer between an expanded position and a collapsed position. 
         [0023]    In a further non-limiting embodiment of any of the foregoing methods, the method includes the step of closing off a bottom of the pocket with at least one flap. 
         [0024]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
         [0025]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  schematically illustrates a powertrain of an electrified vehicle. 
           [0027]      FIG. 2  illustrates a battery cell spacer that can be utilized to physically separate battery cells of a battery module. 
           [0028]      FIG. 3  illustrates a top view of a battery cell spacer. 
           [0029]      FIG. 4  illustrates a first embodiment of an end wall of a battery cell spacer. 
           [0030]      FIG. 5  illustrates a second embodiment of an end wall of a battery cell spacer. 
           [0031]      FIGS. 6A ,  6 B and  6 C illustrate embodiments of a flap of a battery cell spacer. 
           [0032]      FIGS. 7A and 7B  illustrate another embodiment of a flap of a battery cell spacer. 
           [0033]      FIGS. 8A and 8B  illustrate yet another embodiment of a battery cell spacer flap. 
           [0034]      FIG. 9  schematically illustrates a first step of a battery module packaging method. 
           [0035]      FIG. 10  schematically illustrates another step of a battery module packaging method. 
           [0036]      FIG. 11  schematically illustrates yet another step of a battery module packaging method. 
           [0037]      FIG. 12  illustrates a battery cell spacer according to another embodiment of this disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]    This disclosure relates to a battery cell spacer for use within a battery module that accommodates one or more battery cells. The battery cell spacer may include a unitary or molded body made up of a plurality of walls. A pocket extends between adjacent dividing walls of the plurality of walls and can accommodate a battery cell. End or hinged walls may connect between the adjacent dividing walls. The unitary body of the battery cell spacer is adjustable between a first position and a second position, such as by applying a compressive force, to change a dimension of the pocket. These and other features are discussed in greater detail herein. 
         [0039]      FIG. 1  schematically illustrates a powertrain  10  of an electrified vehicle  12 . The electrified vehicle  12  may be a HEV, PHEV, BEV, or any other vehicle. In other words, this disclosure is not limited to any particular type of electrified vehicle. 
         [0040]    The powertrain  10  includes a drive system having at least a motor  36  (i.e., an electric machine) and a battery system  50 . The battery system  50  may include a high voltage battery that is capable of outputting electrical power to operate the motor  36 . Although not shown, the battery system  50  may be made up of multiple battery modules. 
         [0041]    The drive system generates torque to drive one or more sets of vehicle drive wheels  30  of the electrified vehicle  12 . For example, the motor  36  can powered by the battery system  50  and employed to electrically drive the vehicle drive wheels  30  by outputting torque to a shaft  46 . Of course, this view is highly schematic. It should be appreciated that other components, including but not limited to an internal combustion engine, a generator, a power transfer unit, and one or more control systems, could make up the powertrain  10  of the electrified vehicle  12 . 
         [0042]      FIGS. 2 and 3  illustrate a battery cell spacer  60  that can be used to construct a battery module  100  that includes one or more battery cells  62 . The battery cells  62  are illustrated in  FIG. 2  but are omitted in  FIG. 3 . The battery cell spacer  60  is scalable in size to accommodate any number of battery cells  62  and is not necessarily limited to the size, shape and configuration of the illustrated embodiment. For example, the battery cell spacer  60  could accommodate a single battery cell  62  or a multitude of battery cells  62  within the scope of this disclosure. 
         [0043]    The battery cell spacer  60  may be a single-piece, unitary or molded part. For example, the battery cell spacer  60  may be a monolithic structure. The battery cell spacer  60  includes an accordion shape, in one non-limiting embodiment. 
         [0044]    The battery cell spacer  60  may include a molded body  64  (or unitary body) made up of a plurality of walls  66 . The plurality of walls  66  include dividing walls  68  that are spaced apart from one another along a longitudinal axis A (see  FIG. 3 ), and end walls  70  that connect adjacent dividing walls  68  relative to one another. The end walls  70  are generally transverse to the dividing walls  68 . 
         [0045]    A pocket  72  extends between adjacent dividing walls  68  of the plurality of walls  66 . Each pocket  72  defines an open space of the battery cell spacer  60  for accommodating a battery cell  62 . For example, one battery cell  62  may be received within each pocket  72  to construct the battery module  100 . The plurality of walls  66  may optionally include bottom walls  76  (see  FIG. 2 ) that close-off the pockets  72  of the battery cell spacer  60 . 
         [0046]    In one embodiment, the dividing walls  68  are disposed in parallel to one another along the longitudinal axis A of the molded body  64 . The dividing walls  68  are parallel with faces  74  of the battery cells  62 . 
         [0047]    In another non-limiting embodiment, the molded body  64  of the battery cell spacer  60  is adjustable between a first, expanded position and a second, compressed position to change a dimension D of the pocket(s)  72  (see  FIG. 3 ). For example, the molded body  64  may be collapsible, such as by a compressive force, to move the dividing walls  68  into closer proximity with the battery cells  62 . The adjustability of the battery cell spacer  60  is discussed in greater detail below with respect to  FIGS. 9 ,  10  and  11 . 
         [0048]    In one embodiment, the molded body  64  is adjustable to any position between a fully expanded position (see  FIGS. 3 ,  9  and  10 ) and a fully compressed position (see  FIG. 11 ) by virtue of the inherent flexibility in one or more of the plurality of walls  66 . The inherent flexibility of the molded body  64  may be provided by the end walls  70  or any other of the plurality of walls  66 . 
         [0049]    In another embodiment, shown in  FIG. 4 , one or more of the end walls  70  include a living hinge  78 . The living hinge  78  may be a thinned portion of the end wall  70  that allows the end wall  70  to collapse upon itself. For example, the end wall  70  may be thinned at an apex  82 . The presence of the molded-in angled shape at the apex  82  causes the material of the end wall  70  to act as a living hinge. 
         [0050]    By collapsing the end walls  70 , the dividing walls  68  move closer to one another and change the dimension D associated with each pocket  72 . Put another way, the spaces between the dividing walls  68  are reduced by collapsing the end walls  70 . 
         [0051]    Another living hinge  178  is illustrated in  FIG. 5 . In this disclosure, like reference numbers designate like elements where appropriate and reference numerals with the addition of  100  or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding original elements. 
         [0052]    In this embodiment, the living hinge  178  includes a flap of material  80  rather than a thinned portion of the end wall  70 . For example, an apex  82  of the end wall  70  may include the flap of material  80 , which is a flexible walled section that acts as the living hinge  170  to collapse the end wall  70  during compression of the battery cell spacer  60 . This design may be particularly useful where the material used to form the battery cell spacer  60  is relatively stiff. Other living hinge configurations are also contemplated as within the scope of this disclosure. 
         [0053]      FIGS. 6A and 6B  illustrate additional features that may be incorporated into a battery cell spacer  60 . In this embodiment, each of the dividing walls  68  include a flap  84  that is movable to close off a bottom  86  of the pocket  72 . The flaps  84  may be connected to the dividing walls  68  by a hinge  88 . 
         [0054]    The flaps  84  are rotatable or otherwise movable via the hinge  88  between a first position P 1  (see  FIG. 6A ) and a second position P 2  (see  FIG. 6B ) to close off the bottom  86  of the pocket  72 . The second position P 2  is generally transverse to the first position P 1 . In one non-limiting embodiment, a flap  84 - 1  of a first dividing wall  68 - 1  and a flap  84 - 2  of a second dividing wall  68 - 2  are pivoted toward one another to close off the bottom  86 . 
         [0055]    Alternatively, as shown in  FIG. 6C , a single flap  84 - 3  may be provided on the dividing walls  68 . The flap  84 - 3  is pivotable about a hinge  88 - 2  to close-off the bottom  86 . The flap  84 - 3  may fold perpendicular under the battery cells to increase electrical isolation and creepage distance. 
         [0056]    In another embodiment illustrated by  FIGS. 7A and 7B , dividing walls  168  of a battery cell spacer  60  include opposed flaps  184 - 1 ,  184 - 2  that are engageble relative to one another to close off a bottom  86  of a pocket  72 . The flap  184 - 1  extends transverse from a first dividing wall  168 - 1  and the flap  184 - 2  extends transverse from a second dividing wall  168 - 2 . As the battery cell spacer  60  is adjusted (such as by collapsing one or more of the plurality of walls  66 ), a tongue  90  of the flap  184 - 2  is received within an opening  92  of the flap  184 - 1  to lock the flaps  184  relative to one another, thereby sealing off the bottom  86  of the pocket  72  (see  FIG. 7B ). 
         [0057]      FIGS. 8A and 8B  illustrate yet another embodiment of a flap  284  that may be designed into each dividing wall  268  of a battery cell spacer  60 . In this embodiment, a flap  284 - 1  extends transverse from a first dividing wall  268 - 1  and the flap  284 - 2  extends transverse from a second dividing wall  268 - 2 . In one embodiment, the flap  284 - 1  is offset from the flap  284 - 2 . In other words, an axis F 1  through the flap  284 - 1  is offset from an axis F 2  that extends through the flap  284 - 2 . In this way, during compression of the battery cell spacer  60 , the flaps  284 - 1 ,  284 - 2  slide over one another to close off a bottom  86  of a pocket  72 . One or both of the flaps  284 - 1 ,  284 - 2  could include a locating feature for guiding the flaps  284 - 1 ,  284 - 2  during the sliding movement that occurs therebetween. 
         [0058]      FIGS. 9 ,  10  and  11  schematically illustrate a battery module packaging method. As shown in  FIG. 9 , one or more battery cells  62  may be positioned within pockets  72  of a battery cell spacer  60 . The battery cells  62  are positioned within the pockets  72  with the battery cell spacer  60  in a first position Z 1  (i.e., an expanded or non-collapsed position). In the first position Z 1 , the pockets  72  of the battery cell spacer  60  include a dimension D 1  that is greater than the width of the battery cells  62  to provide clearance for receiving the battery cells  62 . The battery cells  62  may be positioned within the pockets  72  either manually or via an automated assembly process. 
         [0059]    As shown in  FIG. 10 , an array structure  94  may be positioned at one or both ends of the battery cell spacer  60 . In one embodiment, the array structures  94  are molded as part of the unitary battery cell spacer  60 . Alternatively, the array structures  94  could be separate structures that are attached to the battery cell spacer  60 . 
         [0060]    The battery cell spacer  60  is next adjusted to a second position Z 2  (i.e., a compressed position), as show in  FIG. 11 . In the second position Z 2 , the pockets  72  include a dimension D 2  that is smaller than the dimension D 1 . In one embodiment, the battery cell spacer  60  is moved to the second position Z 2  by applying a force F to one or both of the array structures  94 . The force F drives the dividing walls  68  closer to one another in order to collapse the battery cell spacer  60  about the battery cells  62 . Rails, bands, straps or other tensioning members may be used to maintain the assembled battery module in the second position Z 2 . 
         [0061]    Optionally, either during or after the compressing step shown in  FIG. 11 , a bottom of each pocket  72  may be closed off in the manners illustrated with respect to  FIGS. 6A ,  6 B,  7 A,  7 B,  8 A and  8 B. 
         [0062]    The battery cell spacer  60  of  FIGS. 3-11  is particularly suitable for a liquid cooled battery system.  FIG. 12  illustrates another exemplary battery cell spacer  160  that may be suited for an air cooled battery system. 
         [0063]    The exemplary battery cell spacer  160  may include a unitary body  164  made up of a plurality of walls  166 . The plurality of walls  166  include dividing walls  168  that are spaced apart from one another in a parallel relationship. A pocket  172  extends between adjacent dividing walls  168  of the plurality of walls  166 . Each pocket  172  defines an open space of the battery cell spacer  160  for accommodating a battery cell  162 . For example, one battery cell  162  may be received within each pocket  172  to construct a battery module. 
         [0064]    In one embodiment, each dividing wall  168  includes a plurality of standoffs  199  that protrude inwardly from the dividing walls  168  in a direction toward the battery cells  162  (once the cells are positioned within the pockets  172 ). The standoffs  199  space the dividing walls  168  away from the battery cells  162  such that airflow  197  can pass between the dividing walls  168  and the battery cells  162  for cooling purposes. 
         [0065]    One or more hinged walls  195  may connect adjacent dividing walls  168  to one another. In one non-limiting embodiment, the unitary body  164  of the battery cell spacer  160  is adjustable between a first, expanded position and a second, compressed position by collapsing the hinged walls  195 . The hinged walls  195  do not extend across an entire height of the dividing walls  168  such that open spaces  191  may be defined at the dividing wall  168  ends. By collapsing the hinged walls  195 , the dividing walls  168  are moved closer to one another and in closer proximity to the battery cells  162 . 
         [0066]    Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0067]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0068]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.