TECHNICAL FIELD
[0001] The present disclosure, in general, relates to a battery pack structure for electric vehicles and, more particularly, to a battery pack module structure to avoid expansion of battery modules in longitudinal direction.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Rechargeable batteries are used as power sources for electric vehicles, hybrid vehicles, electric bicycles, and uninterruptible power supplies, etc. Batteries are used in the form of a single battery cell, or in the form of a battery pack formed by connecting a plurality of battery cells into one unit.
[0004] A mounting structure is required for connecting a plurality of battery cells into one single assembly, and such an assembly structure provides a connecting force for integrating a plurality of battery cells. For example, a lithium ion battery may be used as a battery cell. However, although the performance of the lithium ion battery may not decrease even when charging and discharging are repeatedly performed, during charging, an anode may expand while lithium ions move. In particular, in the case of a battery pack formed by connecting the plurality of battery cells, even when each of the battery cells expands slightly, the battery pack including the battery cells may expand considerably. As described above, when the battery pack is significantly deformed, electric resistance of battery cells increases and electric characteristics thereof may decrease.
[0005] Further, when a distortion moment is applied to a battery pack due to an external element, a distortion deformation may occur due to the lack of rigidity, and in this case, charging and discharging characteristics due to the deformation of the battery pack may deteriorate.
OBJECTS OF THE DISCLOSURE
[0006] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0007] The principal object of the present invention is to provide a battery pack module structure that applies constant compressive force on a plurality of battery cells in a direction opposite to expansion of the plurality of battery cells.
[0008] Another object of the present invention is to provide a front-end plate that applies constant compressive force on front-end of the plurality of battery cells.
[0009] Another object of the present invention is to provide bolting direction of the front-end plate opposite to direction of expansion of the plurality of battery cells.
[0010] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.
SUMMARY
[0011] This summary is provided to introduce concepts related to a battery pack module structure with constant compressive force applied in direction opposite to direction of expansion of battery cells. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0012] In an embodiment, the present disclosure relates to a battery pack module structure for packing a plurality of battery cells placed in a stack in longitudinal direction to avoid expansion. The battery pack module structure includes a pair of side enclosing plates having bent portions at rear end (R) that connects with a rear end plate by bolts in direction (X). Further, a front-end plate is coupled with the pair of side plates at front-end (F) to apply constant compressive force on the plurality of battery cells (101). The front-end plate includes a base plate and two ‘S’ shaped brackets that are mounted on the base plate at a transverse distance in direction (Y). Further, the two ‘S’ shaped brackets are mounted opposite to each other to define a claw shape to receive front bent portions of the side enclosing plates. The two ‘S’ shaped brackets are coupled with the pair of side enclosing plates through a plurality of bolts. In the coupled position, the base plate of the front plate applies constant compressive force on the front-end of the battery pack.
[0013] In an aspect, the two ‘S’ shaped brackets having a base member mounted with the base plate of the front-end plate and a vertical member extend from the base member in perpendicular direction away from the base plate. Further, a bent member extends perpendicularly from the vertical member in parallel direction with the base plate. The bent members bent toward side end of the base plate and are opposite to each other. The S shaped brackets in combination with the base plate define a claw shape structure.
[0014] In an aspect, the bent members of the S shaped brackets have a plurality of mounting holes in vertical direction (Z) to mount the bent members of the front-end plate with the pair of side enclosing plates with a plurality of bolts (106) in direction (X’).
[0015] In an aspect, the base members are spot welded with the base plate.
[0016] In an aspect, the base plate and the bent members of the front-end plate has a gap (G) in direction X that defines pressure to be applied on the plurality of battery cells in direction (X’). If the gap is more, more pressure can be applied on the plurality of cells and the battery cells can be compressed accordingly.
[0017] In an aspect, ‘L’ shaped brackets are mounted at the front-end of the pair of the side enclosing plates in vertical direction (Z) to engage with the claw shape structure defined by the front-end plate of the battery pack module structure.
[0018] In another embodiment, present disclosure describes a method for assembling a plurality of plates surrounding a plurality of battery cells to avoid expansion in direction (X). In the present method, the plurality of plates is placed to define a cage structure to enclose the plurality of battery cells in a row in longitudinal direction (X). More specifically, a pair of side enclosing plates is fixed with a rear end plate by inserting bolts in direction (X). A front-end plate is then pushed towards the plurality of battery cells by applying a compressive force in direction (X’) and coupling ‘S’ shaped brackets of the front-end plate to front bent portions of the side enclosing plates to mount the front-end plate with the plurality of battery cells in a state where the compressive force is constantly applied on the plurality of battery cells in direction (X’) to avoid expansion.
[0019] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0021] Fig. 1 illustrates un-assembled view of battery pack module structure, in accordance with an embodiment of the present disclosure;
[0022] Fig. 2 illustrates assembled view of battery pack module structure as shown in figure 1, in accordance with an embodiment of the present disclosure;
[0023] Fig. 3 illustrates structure of front-end plate of Fig. 1, in accordance with an embodiment of the present disclosure;
[0024] Fig. 4 illustrates top view of the front-end plate of fig. 1, in accordance with an embodiment of the present disclosure;
[0025] Fig. 5 illustrates top view of fig. 2, in accordance with an embodiment of the present disclosure; and
[0026] Fig. 6 illustrates mounting of front-end plate with side enclosing plates, in accordance with an embodiment of the present disclosure.
[0027] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein
DETAILED DESCRIPTION
[0028] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0029] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the tennis “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0031] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0033] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0034] In the subsequent figures arrow X indicates longitudinal/length direction, arrow Y indicates transverse/width direction, and arrow Z indicates height/vertical direction.
[0035] Figs. 1 and 2 illustrate perspective views of a battery pack module 100 according to an embodiment in exploded and packed condition. As shown in the Figs. 1 and 2, the battery pack module of the present embodiment may include a row of a plurality of battery cells 101 connected in series and a plurality of plates surrounding the row of the battery cells 101. The plurality of plates includes a pair of side enclosing plates 102, 103, rear end plate 104 and front-end plate 105. Further, a base plate and a top plate may be provided below and above the row of battery cells 101. For the clarity and to avoid ambiguity in the present subject matter, the top plate and the bottom plate is not explained in the present disclosure.
[0036] When the plurality of battery cells 101 expand during charging operations, the expansion of the battery cells 101 may not largely affect the battery pack module in a Y-axis direction or in a Z-axis direction. However, the expansion of the battery cells 101 in the X-axis direction may greatly affect the battery pack module due to a combined expansion of the battery cells in X-axis direction. Therefore, the battery pack module may be deformed in the X-axis direction, and accordingly, a great amount of pressure may be applied to the battery cells in direction opposite to the expansion direction in X’-axis to avoid deformation. Accordingly, the rear end plate 104 and the front-end plate 105 need to be reinforced and apply pressure on the battery cells to avoid deformation. If required pressure is not applied on the battery cells, the battery cells may expand or the battery pack module structure may get damaged due to battery cell vibration in vehicle running condition. Further, electrical resistance in the battery cells 101 may increase due to the expansion. Thus, a lifespan of the battery module may be reduced.
[0037] To this, the present disclosure provides the battery pack module structure 100 that applies constant pressure or constant compressive force on one end of the row of battery cells 101. As per present disclosure, the battery pack module structure 100 may apply constant compressive force on both ends of the row of the battery cells 101. The pair of side enclosing plates 102, 103 may be coupled to side surfaces (right side and left side) of the row of the battery cells 101 along longitudinal direction X. The pair of side enclosing plates 102, 103 has rear bent portions 102c, 103c facing towards each other. The rear bent portions 102c, 103c of the side enclosing plates 102, 103 is coupled to the end plate 104 at rear end to support the row of battery cells 101 in direction X from rear side portions of the row of battery cells 101. The end plate 104 may prevent the battery cells 101 from moving in a direction in which the battery cells 101 are connected (X-axis direction).
[0038] The side enclosing plates 102, 103 have front bent portions 102a, 103a that faces each other. The front bent portions 102a, 103a are bent in inward direction facing each other. In an embodiment, L shaped brackets 102a, 103a are mounted on interior surface of the side enclosing plates 102, 103 at front-end in vertical direction Z. The L shaped brackets 102a, 103a are spot welded with the side enclosing plates 102, 103. The horizontal portion of the L shaped brackets 102a, 103a faces each other. The L shaped brackets 102a, 103a has a plurality of mounting holes that are inline with a plurality of mounting holes 302d, 303d (as shown in figure 3) to receive a plurality of bolts during mounting of the front-end plate 105 with the front-end of the battery pack module structure 100.
[0039] In an aspect, the side enclosing plates 102, 103 has a plurality of longitudinal beads 102d, 103d to provide stiffness in longitudinal direction. These longitudinal beads are continuous over the rear bent portions.
[0040] In an embodiment, cylindrical bars 102b, 103b are provided adjacent to the L shaped brackets 102a, 103a to further reinforce the L shaped brackets to receive the front-end plate 105. Further, the cylindrical bars 102b, 103b define mounting structure to mount the battery pack module structure 100 on battery mounting structure that is coupled to lower portion of the electric vehicle.
[0041] As shown in the figure 1, the front-end plate 105 is coupled with the side enclosing plates 102, 103 at the front-end ‘F’. The front-end plate 105 is coupled with the front bent portions 102a, 103a of the side enclosing plates 102, 103 by the plurality of bolts 106. The plurality of bolts 106 are coupled with the inline mounting holes of the front bent portions 102a, 103a and the front-end plate 105. The plurality of bolts 106 are provided in direction X’ which is opposite to direction X.
[0042] Referring to figures 3 and 4 together, the front-end plate 300 (105 of the figure 1) includes a base plate 301 having a plurality of beads 301a, 301b in transverse direction Y to provide stiffness to the base plate 301. The front-end plate 300 further includes two ‘S’ shaped brackets 302, 303 that are mounted on the base plate 301. The two S shaped brackets 302, 303 are transversely spaced apart from each other in direction Y and face opposite to each other. The two S shaped brackets 302, 303 are coupled with the front bent portions 102a, 103a of the side enclosing plates 102, 103 by the plurality of bolts 106 in direction X’. The S shaped brackets 302, 303 are spot welded on the base plate in vertical direction Z.
[0043] As shown in the figure 4, each of the two S shaped brackets 302, 303 includes base members 302c, 303c that are mounted with the base plate 301 of the front-end plate 300 through spot welding. Further, vertical members 302b, 303b extend from the base members 302c, 303c in perpendicular direction away from the base plate 301. The S shaped brackets 302, 303 further include bent members 302a, 303a that bent perpendicularly from the vertical members 302b, 303b and extend in parallel with the base plate 301. The bent members 302a, 303a extend toward side end of the base plate 301 that are opposite to each other. The bent member 302a extends oppositely to the bent member 303a. The vertical members 302b, 303b and the bent members 302a, 303a define a claw type structure to receive the front bent portions 102a, 103a of the side enclosing plates 102, 103. A gap (G) is defined in between the base plate 301 and the bent members 302a, 303a, the gap ‘G’ defines compressive pressure to be applied on the plurality of battery cells 101 in direction X’. If gap ‘G’ is more, the compressive pressure to be applied on the front-end of the row of battery cells 101 or the plurality of battery cells 101 is more. Accordingly, to increase the compressive pressure on the row of battery cells 101, the gap ‘G’ can be increased. Accordingly, the gap ‘G’ can be decreased to decrease the compressive pressure.
[0044] As shown in figures 3 and 4, the bent members 302a, 303a of the two S shaped brackets 302, 303 include a plurality of mounting holes 302d, 303d in vertical direction (Z) to mount the bent members 302a, 303a of the base plate 301 with the pair of side enclosing plates 102, 103 with the plurality of bolts 106 in direction (X’).
[0045] Figure 5 illustrates top view of the battery pack module structure with the plurality of battery cells. Figure 6 shows front cut section that illustrates mounting of the front-end plate 105 with the side enclosing plates 102, 103.
[0046] In another embodiment, the present subject matter discloses a method for assembling a plurality of plates including side enclosing plates 102, 103, end plate 104, and front-end plate 105 that surround a plurality of battery cells 101 placed in a row in direction X to avoid expansion in direction (X). In the present method, the plurality of plates 102, 103, 104, 105 are placed to enclose the row of the plurality of battery cells 101 in longitudinal direction (X). After placing the plurality of battery cells 101 in a row, the pair of side enclosing plates 102, 103 is fixed to rear end (R) portion of the rear end plate 104 by inserting plurality of bolts in direction (X). The front-end plate 105 is then mounted on the side enclosing plates 102, 103. To mount the front-end plate 105, a push force is applied on the base plate 301 toward the plurality of battery cells 101. Once the ‘S’ shaped brackets 302, 303 of the front-end plate 105 are in surface contact with the front bent portions 102a, 103a of the side plates 102, 103, a plurality of bolts 106 are applied to fix the front-end plate 105 with the bent side portions 102a, 103a. The applied push force on the base plate 301 keeps the plurality of battery cells 101 in a state where the constant push force or constant compressive force is applied on the plurality of battery cells 101 in direction (X’) to avoid expansion.
[0047] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

We claim:
1. A battery pack module structure (100) for packing a plurality of battery cells (101), the battery pack module structure (100) comprising:
a pair of side enclosing plates (102, 103) having rear bent portions (102c, 103c) at rear end (R), the pair of side enclosing plates (102, 103) is provided longitudinally along the plurality of battery cells (101) in direction (X);
a rear end plate (104) connected to the rear bent portions (102c, 103c) of the pair of side enclosing plates (102, 103) at the rear end (R);
a front-end plate (105, 300) coupled to the pair of side enclosing plates (102, 103) at front-end (F) to apply constant compressive force on the plurality of battery cells (101), the front-end plate (105, 300) comprises:
a base plate (301); and
two ‘S’ shaped brackets (302, 303), transversally spaced apart from each other, mounted on the base plate (301), the two ‘S’ shaped brackets (302, 303) face opposite to each other,
wherein the two ‘S’ shaped brackets (302, 303) coupled with the pair of side enclosing plates (102,103) through a plurality of bolts (106).
2. The battery pack module structure (100) as claimed in claim 1, wherein each of the two ‘S’ shaped brackets (302, 303) comprising:
a base member (302c, 303c) mounted with the base plate (301) of the front-end plate (300);
a vertical member (302b, 303b) extended perpendicularly from the base member (302c, 303c), the vertical member (302b, 303b) extends away from the base plate (301); and
a bent member (302a, 303a) bent perpendicularly from the vertical member (302b, 303b) and extended in parallel with the base plate (301), the bent member (302a, 303a) extends toward side end of the base plate (301) that are opposite to each other.
3. The battery pack module structure (100) as claimed in claim 2, wherein the bent member (302a, 303a) includes a plurality of mounting holes (302d, 303d) in vertical direction (Z) to mount the bent members (302a, 303a) of the base plate (301) with the pair of side enclosing plates (102, 103) with a plurality of bolts (106) in direction (X’).
4. The battery pack module structure (100) as claimed in claim 2, wherein the base members (302c, 303c) are spot welded with the base plate (301).
5. The battery pack module structure (100) as claimed in claim 2, wherein a gap (G) between the base plate (301) and the bent members (302a, 303a) defines compressive pressure to be applied on the plurality of battery cells (101) in the direction (X’).
6. The battery pack module structure (100) as claimed in claim 1, wherein the pairs of the side enclosing plates (102, 103) has front bent portions (102a, 103a) that faces each other to receive the front-end plate (105, 300).
7. The battery pack module structure (100) as claimed in claim 6, wherein the front bent portions (102a, 103a) are ‘L’ shaped brackets (102a, 103a) mounted at the front-end of the pair of the side enclosing plates (102, 103) in vertical direction (Z).
8. The battery pack module structure (100) as claimed in claim 1, wherein the pair of side enclosing plates (102, 103) and the front plate (105) includes a plurality of beads (102d, 103d, 301a, 301b).
9. A method for assembling a plurality of plates (102, 103, 104, 105) surrounding a plurality of battery cells (101) to avoid expansion in direction (X), the method comprising:
placing the plurality of plates (102, 103, 104, 105) to enclose the plurality of battery cells (101) in a row in longitudinal direction (X);
fixing rear end (R) portion of a pair of side enclosing plates (102, 103) with a rear end plate (104) from the plurality of plates (102, 103, 104, 105) by inserting bolts in direction (X);
applying a push force on a base plate (301) of a front-end plate (105) from the plurality of plates (102, 103, 104, 105) towards the plurality of battery cells (101); and
coupling ‘S’ shaped brackets (302, 303) of the front-end plate (105) to front bent portions (102a, 103a) of the side enclosing plates (102, 103) to mount the front-end plate (105) with the plurality of battery cells (101) in a state where the push force is constantly applied on the plurality of battery cells (101) in direction (X’) to avoid expansion.
10. The method as claimed in claim 9, wherein the coupling ‘S’ shaped brackets (302, 303) of the front-end plate (105) to the front bent portions (102a, 103a) of the side enclosing plates (102, 103) further includes:
inserting a plurality of bolts (106) on inline mounting holes (302d, 303d) of the front-end plate (105) and the front bent portions (102a, 103a) in direction (X’).