Busbar assembly and battery pack containing it

Abstract

A battery pack comprising: a plurality of battery cells including electrode terminals on one side of a housing; a cell mounting plate to which the plurality of battery cells are coupled; and a bus bar assembly electrically connected to the plurality of battery cells, wherein the cell mounting plate is disposed below the plurality of battery cells and the bus bar assembly is disposed below the cell mounting plate.

Description

Technical FieldThe present disclosure relates to a bus bar assembly and a battery pack including this assembly.Prior ArtSecondary batteries are batteries that can be repeatedly charged or discharged with electricity because the mutual conversion of chemical and electrical energy is reversible.Such secondary batteries can be used as power sources for mobile devices as well as electric vehicles, hybrid vehicles, and energy storage systems (ESSs), which have attracted much attention recently.Secondary batteries may be used in the form in which one or more battery cells are electrically connected, wherein the one or more battery cells are manufactured as flexible, pouch-shaped battery cells or rigid, square or cylindrical can-shaped battery cells. Particularly, in electric vehicles requiring high power, a battery module in which one or more cell stacks having a plurality of battery cells stacked therein are electrically connected or one or more battery modules are electrically connected may be used.Recently, a cell-to-pack method in which one or more battery cells do not form a battery module but directly form a battery pack has attracted attention. Since the battery module is omitted in the cell-to-pack method, this has the advantage that the number of components and the dead space are reduced and the energy density is thus improved.Meanwhile, a plurality of battery cells assembled in a cell-to-pack method are fixed to the bottom of a pack case with an adhesive or tape. However, since the battery cells cannot be firmly connected to the pack case by the adhesive tape or the like, there is a problem that the battery cells can easily shift due to external impact or vibration.SUMMARY OF THE INVENTIONTechnical ProblemThe present disclosure is to provide a bus bar assembly that can easily electrically connect battery cells, and a battery pack including this assembly.Solution of the ProblemA battery pack according to the present disclosure may include: a plurality of battery cells including electrode terminals on a side of a housing; a cell fixing plate to which the plurality of battery cells is coupled; and a bus bar assembly electrically connected to the plurality of battery cells, wherein the cell fixing plate is disposed below the plurality of battery cells and the bus bar assembly is disposed below the cell fixing plate.According to the present disclosure, the bus bar assembly may include: a plurality of bus bars electrically connected to the electrode terminals; a bus bar plate on which the plurality of bus bars is disposed; and a spring elastically supporting the plurality of bus bars.According to the present disclosure, the bus bar assembly may include: a fitting groove to which the electrode terminal is coupled; and an extension portion extending in the longitudinal or width direction of the bus bar plate based on the fitting groove.According to the present disclosure, the electrode terminal may include a fitting protrusion inserted into the fitting groove, and the plurality of battery cells is electrically connected to the plurality of bus bars when the fitting protrusion is coupled to the fitting groove.According to the present disclosure, the fitting protrusion may have a semicircular cross-sectional shape.According to the present disclosure, the spring may be a compression spring or a Belleville spring.According to the present disclosure, the cell mounting plate may include: a base; and a plurality of coupling holes formed in the base including a first hole into which a cathode terminal is inserted among the electrode terminals and a second hole into which an anode terminal is inserted among the electrode terminals, wherein the first hole and the second hole may include a first portion having a first width and a second portion having a second width narrower than the first width.According to the present disclosure, the bus bar assembly may be disposed such that the extension portion faces the first portion and the fitting groove faces the second portion.According to the present disclosure, the plurality of battery cells may include a cover plate coupled to one side of the case and provided with the electrode terminal; and a separation protrusion separating a surface of the electrode terminal from the cover plate, wherein the electrode terminal may be formed to have a width not greater than the first width, and the separation protrusion may be formed to have a width equal to the second width.According to the present disclosure, the plurality of battery cells may include a cover plate coupled to a side of the case and provided with the electrode terminal, and a coupling protrusion formed on a side of the cathode terminal and a side of the anode terminal, respectively, and passing through the first hole and the second hole, and the coupling protrusion may include a portion formed to have a width not greater than the first width and a portion formed to have a width equal to the second width.A bus bar assembly according to an embodiment of the present disclosure may include: a plurality of bus bars disposed on a bottom plate of the pack case and electrically connected to electrode terminals of a plurality of battery cells; a bus bar plate on which the plurality of bus bars is disposed; and a spring elastically supporting the plurality of bus bars.According to an embodiment of the present disclosure, the plurality of bus bars may include: a fitting groove into which the electrode terminal is fitted; and an extension portion extending in the longitudinal or width direction of the bus bar plate with respect to the fitting groove.A battery cell mounting system may include: a vertical moving operation of vertically moving a cell group formed of a plurality of battery cells toward a cell mounting plate and a bus bar assembly disposed below the cell mounting plate and including a plurality of bus bars; and a horizontal moving operation of horizontally moving or rotating the cell group on the cell mounting plate and the bus bar assembly so that the plurality of battery cells are mounted to the cell mounting plate and the bus bar assembly.According to an embodiment of the present disclosure, the electrode terminal may include a fitting protrusion, and the plurality of bus bars may include a fitting groove having a shape corresponding to the fitting protrusion, and in the horizontal movement operation, the fitting protrusion may be inserted into the fitting groove.According to an embodiment of the present disclosure, the cell fixing plate may include a plurality of coupling holes into which the electrode terminal is inserted and which include a first portion having a first width and a second portion having a second width narrower than the first width, and in the horizontal moving operation, the electrode terminal may be moved from the first portion side to the second portion side.According to an embodiment of the present disclosure, the battery cell may include: a cover plate coupled to one side of the case and provided with the electrode terminal; and a separation protrusion separating a surface of the electrode terminal from the cover plate, wherein the electrode terminal may be formed to have a width not greater than the first width, and the separation protrusion may be formed to have a width equal to the second width.According to an embodiment of the present disclosure, the plurality of bus bars may include an extension portion extending to one side based on the fitting groove, and the extension portion may be disposed to oppose the first portion, and the fitting groove may be disposed to oppose the second portion.According to an embodiment of the present disclosure, when the second portion of the first hole and the second portion of the second hole are formed to be aligned in the same direction and the fitting grooves of the bus bar are formed to be aligned in the same direction, the cell group can be moved in parallel on the cell mounting plate and the bus bar assembly in the horizontal movement.According to an embodiment of the present disclosure, when the second portion of the first hole and the second portion of the second hole are formed to be directed in different directions, and the first hole-facing bus bar and the second hole-facing bus bar may be disposed to be directed in different directions, the cell group may be rotated in the horizontal movement on the cell mounting plate and the bus bar assembly.Advantageous Effects of the InventionAccording to an embodiment of the present disclosure, a battery cell may be electrically connected to a bus bar without a separate welding operation. In addition, since the battery cell is electrically connected to the bus bar while being coupled to the cell mounting plate, the assembly process can be simplified.Brief Description of the DrawingsFIG. 1 is an exploded perspective view of a cell fixing plate and a bus bar assembly in which a battery cell according to an embodiment of the present disclosure is mounted; FIG. 2 is a view showing a state in which a battery cell is mounted on a cell mounting plate according to an embodiment of the present disclosure. FIG. 3 is a rear view of FIG. 2. FIG. 4 is a perspective view of a cell mounting plate according to an embodiment of the present disclosure. FIG. 5 is a perspective view of a battery cell according to an embodiment of the present disclosure. FIG. 6 is a side view of the battery cell of FIG. 5. FIGS. 7A and 7B are views illustrating mounting of a battery cell to a cell mounting plate according to an embodiment of the present disclosure. FIG. 8 is a side cross-sectional view of a bus bar assembly according to an embodiment of the present disclosure. FIGS. 9A and 9B are views illustrating mounting of a battery cell to a bus bar assembly according to an embodiment of the present disclosure. FIG. 10 is a perspective view of a battery cell according to another embodiment of the present disclosure. FIGS. 11A and 11B are views illustrating mounting of a battery cell to a cell mounting plate according to another embodiment of the present disclosure. FIGS. 12A and 12B are perspective views of a bus bar assembly according to another embodiment of the present disclosure.BEST MODE OF THE INVENTIONBefore describing the exemplary embodiments in detail, it should be understood that the terms used in the specification and the appended claims should not be construed as being limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle of allowing the inventor to appropriately define terms for better explanation. Therefore, the description provided herein is merely an advantageous example for purposes of illustration and is not intended to limit the scope of the disclosure, so that other equivalents and changes may be made thereto without departing from the spirit and scope of the disclosure.The same reference number or symbol in each accompanying drawing of the specification refers to parts or components that substantially perform the same function. The present inventive concept is also described in various embodiments with the same reference number or the same symbol for ease of description and for better understanding. Although all the components having the same reference number are illustrated in a plurality of drawings, the plurality of drawings do not necessarily refer to a single exemplary embodiment.In this specification, the singular also includes the plural, unless expressly stated otherwise. It will also be understood that the terms "comprises," "comprising," "includes," and / or "including," when used herein, specify the presence of particular features, integers, steps, operations, elements, components, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.Moreover, it should be noted in advance that the expressions such as "upper / above", "upper", "lower / below", "under", "lower", "lateral", "front" and "rear" are based on the directions illustrated in the drawings, and may be expressed differently when the direction of the object is changed.Moreover, although the terms "first", "second", etc. may be used herein to describe various elements, it should be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element could be referred to as a second element, and likewise a second element could be referred to as a first element, without departing from the scope of the present disclosure.Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.FIG. 1 is an exploded perspective view of a cell fixing plate and a bus bar assembly in which a battery cell according to an embodiment of the present disclosure is mounted, FIG. 2 is a view illustrating a state in which a battery cell is mounted on a cell fixing plate according to an embodiment of the present disclosure, FIG. 3 is a rear view of FIG. 2, and FIG. 4 is a perspective view of a cell fixing plate according to an embodiment of the present disclosure.According to an embodiment of the present disclosure, a battery cell 100 may be disposed in a battery pack (not illustrated) in a state where the battery cell 100 is mounted on a cell mounting plate 200. Moreover, the battery cell 100 may be mounted to a bus bar assembly 300 together with the cell mounting plate 200. That is, the battery pack according to an embodiment of the present disclosure may have a structure illustrated in FIG. 1 within the housing of the pack.According to an embodiment of the present disclosure, the cell fixing plate 200 may be disposed in a pack case of the battery pack. For example, the cell mounting plate 200 may be disposed in a bottom plate (not shown) that forms a bottom surface of the battery pack. The cell mounting plate 200 may be one of a plurality of components constituting the pack case.A plurality of battery cells 100 may be disposed in the cell mounting plate 200. The plurality of battery cells 100 may be arranged in a matrix shape in a longitudinal direction (or X direction) and a width direction (or Y direction) of the cell fixing plate 200.The cell fixing plate 200 may include a base 210, a guide groove 220, a partition wall 230, and a communication hole 240. The guide groove 220, the partition wall 230, and the coupling hole 240 may all be provided in the base 210.The guide groove 220 and the partition wall 230 may be provided on an opposite surface to a surface on which the battery cells 100 are arranged. For example, the guide groove 220 and the partition wall 230 may be provided on a bottom surface of the bottom 210. The guide groove 220 and the partition wall 230 may be provided alternately in a width direction of the bottom 210. A gap between two adjacent partition walls 230 in the width direction of the base 210 may be a width of the guide groove 220, and for example, the width of the guide groove 220 may be approximately the same as a width of the battery cell 100. Accordingly, the battery cell 100 may be firmly aligned with the guide groove 220.The partition walls 230 may be alternately arranged with the guide grooves 220 to separate adjacent guide grooves 220. Accordingly, the battery cells 100 aligned with different guide grooves 220 may be spatially and thermally separated at least on one side. For example, a space separated by the partitions 230 may be filled with air (e.g., an air gap), and heat transfer between the battery cells 100 aligned with different guide grooves 220 may be blocked and delayed.The coupling hole 240 is a hole penetrating through the base 210 in the thickness direction, and the battery cell 100 can be fixed to the base 210 through the coupling hole 240. For example, the battery cell 100 may be fixed to the base 210 in a state where the electrode terminals 131 and 132 are arranged to pass through the coupling hole 240.The coupling hole 240 may be formed to have a predetermined interval in a longitudinal direction of the guide groove 220 on the base 210 (which is identical to the longitudinal direction of the base 210). Referring to FIG. 4, the coupling hole 240 may include a first hole 241 and a second hole 242 having different shapes, and the first hole 241 and the second hole 242 may be alternately formed in the longitudinal direction of the guide groove 220.Before describing the coupling hole 240 in detail, the battery cell 100 will be described.FIG. 5 is a perspective view of a battery cell according to an embodiment of the present disclosure, FIG. 6 is a side view of the battery cell of FIG. 5, and FIG. 10 is a perspective view of a battery cell according to another embodiment of the present disclosure.The battery cell 100 disposed on the cell mounting plate 200 may be a square battery cell as illustrated in FIG. 5. The square battery cell may refer to a battery cell in which a case 110 including an electrode assembly and an electrolyte has a flat and square shape.A cover plate 120 may be coupled to one side of the housing 110. The cover plate 120 may be provided with electrode terminals 131 and 132 and a vent portion 140. In addition, an electrolyte injection port 150 for injecting an electrolyte into the inside of the case 110 may be provided.The battery cells 100 arranged side by side in the battery pack may be electrically connected via electrode terminals 131 and 132 (more specifically, via a bus bar connected to the electrode terminals). The electrode terminals 131 and 132 may include a cathode terminal 131 and an anode terminal 132, and the cathode terminal 131 and the anode terminal 132 may be spaced apart from each other in the longitudinal direction on the cover plate 120. In addition, the above-described vent portion 140 may be provided between the cathode terminal 131 and the anode terminal 132.Referring to FIG. 5, between the electrode terminals 131 and 132 and the cover plate 120, a separation protrusion 133 may be formed that separates a wide area of the electrode terminals 131 and 132 from the cover plate 120. The separation protrusion 133 may be a part of the electrode terminals 131 and 132 or a part of an insulating plate (not illustrated) disposed between the electrode terminals 131 and 132 and the cover plate 120.Specifically, the case 110 and the cover plate 120 of the square battery cell may be formed of a material containing aluminum, and accordingly, the case 110 and the cover plate 120 themselves may have a positive electrode. Accordingly, the cathode terminal 131 may be configured to be in direct contact with the cover plate 120, but an insulating plate should be disposed between the anode terminal 132 and the cover plate 120 to electrically insulate the anode terminal 132 from the cover plate 120. Accordingly, the separation protrusion 133 illustrated in FIG. 5 may be a part of the cathode terminal 131 or a part of the insulating plate disposed between the anode terminal 132 and the cover plate 120.As illustrated in FIG. 6, the electrode terminals 131 and 132 may have a first width B 1, and the separation protrusion 133 may have a second width B 2 narrower than the first width B 1. Accordingly, as viewed in the longitudinal direction (or X direction), parts of the electrode terminals 131 and 132 may have a "T-shaped" cross section.The separation protrusion 133 may be formed to have a second width B 2 narrower than that of the electrode terminals 131 and 132 to fix the battery cell 100 to the base 210, which will be described in detail below.In addition, the electrode terminals 131 and 132 (see FIG. 5 ) may include a fitting protrusion 134. Each of the electrode terminals 131 and 132 may include two fitting protrusions 134. The fitting protrusions 134 may have, for example, a curved surface, preferably a semicircular shape. The fitting protrusions 134 may be spaced apart from each other in the longitudinal direction (or X direction) of the battery cell 100 at the electrode terminals 131 and 132. The fitting protrusion 134 may be a part electrically connected to a bus bar 320 of the bus bar assembly 300, and a detailed description thereof will be described later.In this specification, an embodiment in which the battery cell 100 is fixed to the base 210 in a state in which the electrode terminals 131 and 132 are arranged to pass through the coupling holes 240 is mainly described, but as illustrated in FIG. 10, the battery cell 100 may include a separate configuration fixed to the coupling holes 240.Referring to FIG. 10, the battery cell 100 may include a coupling protrusion 160 fixed to the coupling holes 240 instead of the electrode terminals 131 and 132. The coupling protrusion 160 may include a portion having a first width C 1 and a portion having a second width C 2, similarly to the electrode terminals 131 and 132 in the above-described embodiment, and may instead be formed of an insulating material.The coupling protrusion 160 may be provided on the cover plate 120 together with the electrode terminals 131 and 132. The coupling protrusions 160 may be provided on a side of the cathode terminal 131 and a side of the anode terminal 132, respectively. In an embodiment, the coupling protrusion 160 may be provided on an inner side of the electrode terminals 131 and 132 with respect to the vent portion 140 disposed in a central portion of the cover plate 120, as illustrated in FIG. 10. However, the position of the coupling protrusion 160 is not particularly limited as long as the coupling protrusions 160 are provided on both sides with respect to the vent portion 140. That is, in another embodiment, the coupling protrusion 160 may be disposed on an inner side or an outer side of the electrode terminals 131 and 132 with respect to the ventilation portion 140.Next, the coupling hole 240 formed in the base 210 will be described.The base 210 may include a plurality of coupling holes 240 formed at predetermined intervals in a longitudinal direction of the guide groove 220. The plurality of coupling holes 240 may be the first hole 241 or the second hole 242, and the first hole 241 and the second hole 242 may be provided alternately in the longitudinal direction of the guide groove 220.A single battery cell ( 100) may be connected and fixed to the base ( 210) through the first hole ( 241) and the second hole ( 242) that are adjacent to each other. For example, the cathode terminal 131 of the single battery cell 100 may be coupled to the first hole 241 in a state of being disposed to pass through the first hole 241, and the anode terminal 132 may be coupled to the second hole 242 in a state of being disposed to pass through the second hole 242 provided adjacent to the first hole 241, so that the single battery cell 100 may be fixed to the base 210. Alternatively, a component connected to the first hole 241 and the second hole 242 may be a coupling protrusion 160.The vent portion 140 that discharges the gas generated inside the housing 110 may be provided between the cathode terminal 131 and the anode terminal 132 in the single battery cell 100. Referring to FIG. 4, the first hole 241 may have a shape longer than the second hole 242 in a longitudinal direction (or X direction), which may serve to expose the vent portion 140 toward the bottom surface of the base 210. That is, the first hole 241 may have a shape extending more than the second hole 242 in the X direction by a length of the vent portion 140. Moreover, the gap between the first holes 241 and the second holes 242 adjacent to each other may approximately correspond to a gap between the vent portion 140 and the anode terminal 132 (or the cathode terminal 131) of the battery cell 100 or a gap between the vent portion 140 and the coupling protrusion 160.Referring to FIG. 4, the first hole 241 and the second hole 242 may include a portion (hereinafter, the first portion) having a first width A 1 and a portion (hereinafter, the second portion) having a second width A 2 narrower than the first width A 1. The first hole 241 and the second hole 242 may be arranged such that the second portion is in the same direction, e.g., in the +X direction as viewed in the drawing.The width A 1 of the first portion of the first hole 241 and the second hole 242 may be the same as the first width B 1 of the electrode terminals 131 and 132 or larger than the first width B 1 of the electrode terminals 131 and 132. Accordingly, the electrode terminals 131 and 132 can be inserted into the first hole 241 and the second hole 242 through the first portion.The width A 2 of the second portion of the first hole 241 and the second hole 242 may be approximately equal to the second width B 2 of the separation protrusion 133, preferably it is equal. The separation protrusion 133 may be fitted into the first hole 241 and the second hole 242 in the second portion, and the battery cell 100 may be fixed to the base 210.According to an embodiment of the present disclosure, as illustrated in FIG. 1, the bus bar assembly 300 may be disposed below the cell mounting plate 200.FIG. 8 is a side cross-sectional view of a bus bar assembly according to an embodiment of the present disclosure.As illustrated in FIG. 8, the bus bar assembly 300 may include a bus bar plate 310 and a bus bar 320 disposed on the bus bar plate 310.The bus bar plate 310 may be formed of a material having structural rigidity and insulating properties to support the battery cell 100.On the bus bar plate 310, a plurality of bus bars 320 may be disposed. Specifically, the bus bar 320 may be disposed on the bus bar plate 310 in a state where the bus bar 320 is supported by a spring 330. The bus bar plate 310 may include a spring groove 311 in which the spring 330 is disposed, and in an embodiment, the spring 330 may be a compression spring elastically deformable in a height direction (or Z direction). A gap may be formed between the bus bar 320 and the bus bar plate 310 in the height direction (or Z direction) by the spring 330.The bus bar 320 may be electrically connected to the electrode terminals 131 and 132 of the battery cell 100, and to this end, the bus bar 320 may be disposed on the bus bar plate 310 so as to face the electrode terminals 131 and 132 of the battery cell 100 in the height direction (or Z direction). Each of the bus bars 320 may face the cathode terminal 131 or the anode terminal 132 in the height direction (or Z direction).Meanwhile, as described above, the electrode terminals 131 and 132 may be electrically connected to the bus bar 320 via a part of the fitting protrusion 134. The bus bar 320 may include a fitting groove 321 into which the fitting protrusion 134 of the electrode terminals 131 and 132 is inserted, and the fitting groove 321 may be opposed to the second portion to which the electrode terminals 131 and 132 are fixed in a height direction (or Z direction). Moreover, the fitting groove 321 may be provided in a shape corresponding to the fitting protrusion 134, so that the fitting protrusion 134 can be inserted and fixed thereto, and the fitting groove 321 may be provided in a number and a distance corresponding to the fitting protrusion 134. That is, according to an embodiment of the present disclosure, electrical connection between the electrode terminals 131 and 132 of the battery cell 100 and the bus bar 320 may be implemented in a shape in which the fitting protrusion 134 is inserted into the fitting groove 321, and welding operation may be omitted.Additionally, the bus bar 320 may have a length in the longitudinal direction (or X direction) to allow horizontal movement of the battery cell 100 during assembly of the battery cell 100. For example, the bus bar 320 may have a shape extending to a side of the fitting groove 321. Hereinafter, this portion is referred to as an extension portion 322, and the extension portion 322 may face the first portion of the coupling hole 240 in the height direction (or Z direction).The following describes the mounting of the battery cell 100 to the cell mounting plate 200 and the bus bar assembly 300.FIGS. 7A and 7B are views illustrating the mounting of a battery cell to a cell mounting plate according to an embodiment of the present disclosure, and FIGS. 9A and 9B are views illustrating the mounting of a battery cell to a bus bar assembly according to an embodiment of the present disclosure.According to an embodiment, the battery cell 100 may be mounted on the cell mounting plate 200 by a vertical and a horizontal movement operation.The battery cell 100 may be assembled into a cell group unit (100G). In an embodiment, a plurality of battery cells 100 arranged in the longitudinal direction (or X direction) may form a cell group 100G. As illustrated in FIGS. 7A and 7B, three longitudinally arranged battery cells 100 may form a cell group 100G. The one cell group 100G may be composed of a number of battery cells 100 corresponding to the number of the first hole 241 and the second hole 242 provided along the guide groove 220.The one cell group 100G may move vertically toward the base 210 (hereinafter, referred to as a vertical movement operation). In the vertical movement, the one cell group 100G may be inserted into the coupling hole 240 formed in the base 210.The one cell group 100G may be vertically moved from a top surface of the base 210 toward the base 210. The one cell group 100G may be vertically moved in a state where the cathode terminals 131 and the anode terminals 132 of the plurality of battery cells 100 are aligned to correspond to the first portions of the first hole 241 and the second hole 242, respectively. As described above, since the width A 1 of the first portion of the first hole 241 and the second hole 242 is formed to be equal to or greater than the first width B 1 of the electrode terminals 131 and 132 than the first width B 1 of the electrode terminals 131 and 132, the cathode terminal 131 and the anode terminal 132 can be inserted into the first hole 241 and the second hole 242, respectively, through the first portion and disposed on the bottom surface of the base 210. In this case, the electrode terminals 131 and 132 may pass through the first portion, and the separation protrusion 133 may be disposed in the first portion, so that the one cell group 100G may be loosely coupled to the base 210.The one cell group 100G may move horizontally in a state of being loosely connected to the base 210. A horizontal movement direction may be the +X direction based on the drawing, which may be a direction in which the first hole 241 and the second portion of the second hole 242 are arranged. That is, by the horizontal movement of the one cell group 100G, the separation protrusion 133 moves from the first portion to the second portion, and accordingly, a plurality of battery cells 100 can be fixed to the base 210.Since the separation protrusion 133 is disposed in the first portion of the first hole 241 and the second hole 242 when the one cell group 100G is vertically moved, in order to fix the one cell group 100G to the base 210, it is necessary to move the separation protrusion 133 such that the separation protrusion 133 is disposed in the second portion of the first hole 241 and the second hole 242. Accordingly, the one cell group 100G can be horizontally moved in the +X direction, so that the separation protrusion 133 can be disposed in the second portion. As described above, since the width A 2 of the second portion of the first hole 241 and the second hole 242 is equal to the second width B 2 of the separation protrusion 133, the battery cell 100 can be firmly fixed to the base 210 when the separation protrusion 133 moves from the first portion to the second portion. In addition, the vent portion 140 may be exposed through the first hole 241 when the one cell group 100G moves horizontally.The cell fixing plate 200 may also include a fixing member (not shown) that fixes the cell group 100G to the base 210 by the vertical and horizontal movement. The fixing member may prevent the cell group 100G from moving in the X direction while being fixed to the base 210.The fixing member may be fitted into the coupling hole 240 disposed on an opposite side (left side in the drawing) to the horizontal moving direction of the cell group 100G on the lower side of the base 210, for example, the second hole 242 in the drawing. In a state where the cell group 100G is fixed to the base 210, the electrode terminals 131 and 132 and the separation protrusion 133 are disposed in the second portion, and the fixing member may be fitted into the first portion of the second hole 242.The mounting process described in FIGS. 7A and 7B may be performed simultaneously with the mounting process illustrated in FIGS. 9A and 9B. That is, the one cell group 100G may be simultaneously fixedly connected to the cell fixing plate 200 and electrically connected to the bus bar 320 of the bus bar assembly 300.Referring to FIG. 9A, the bus bar assembly 300 may be disposed below the cell fixing plate 200, and the one cell group 100G may pass through the coupling hole 240 formed in the base 210 in the vertical movement operation and come into contact with the bus bar assembly 300. Specifically, in the vertical moving operation in which the one cell group 100G vertically moves toward the base 210, the electrode terminals 131 and 132 of the one cell group 100G may be inserted into the coupling hole 240 formed in the base 210 and exposed toward the bus bar assembly 300 disposed below the base 210, so that the electrode terminals 131 and 132 may be placed on the bus bar 320. When the one cell group 100G moves vertically, the electrode terminals 131 and 132 are inserted into the first portion having the first width A 1 of the coupling hole 240, so that the electrode terminals 131 and 132 can be disposed in the first portion-facing extension portion 322, and specifically, the fitting protrusion 134 relatively protruding from a surface of the electrode terminals 131 and 132 can be disposed in the extension portion 322. When the one cell group 100G moves vertically, the spring 330 supporting the bus bar 320 may be compressed, and accordingly, a gap formed in the height direction (or Z direction) between the bus bar 320 and the bus bar plate 310 by the spring 330 may disappear. That is, the bus bar 320 may be closely fixed to the bus bar plate 310.The one cell group 100G may be electrically connected to the bus bar 320 during the horizontal movement. That is, the fitting protrusion 134 of the one cell group 100G may be inserted into the fitting groove 321 by horizontal movement. The one cell group 100G may be moved from the first portion to the second portion by a horizontal movement, and the fitting protrusion 134 disposed on the bus bar 320 may be moved from the extension portion 322 facing the first portion to the fitting groove 321 facing the second portion and inserted into the fitting groove 321. While the battery cell 100 is electrically connected to the bus bar 320, the battery cell 100 may be fixed to the bus bar 320. As described above, since the fitting protrusion 134 has a semicircular cross section, the fitting protrusion 134 can move horizontally while making point contact with the bus bar 320, enabling smooth horizontal movement.Moreover, FIGS. 11A and 11B are views illustrating the mounting of a battery cell to a cell mounting plate according to another embodiment, and FIGS. 12A and 12B are perspective views of a bus bar assembly according to another embodiment of the present disclosure.According to another embodiment, the battery cell 100 may be fixed to the cell fixing plate 200 by a vertical movement and a horizontal rotation.In the corresponding embodiment, the battery cell 100 can be assembled to form a cell group (100G'). However, a plurality of battery cells 100 constituting the cell group 100G' may be arranged approximately in the width direction (or Y direction). As shown in FIGS. 11A and 11B, three battery cells 100 arranged approximately in the width direction may form one cell group 100G'. In this case, the three battery cells 100 may be arranged in a shape inclined at a predetermined angle with respect to the longitudinal direction of the guide groove 220, and the coupling hole 240 may also be formed along the longitudinal direction of the guide groove 220 in a shape inclined in the same direction as the battery cell 100.Referring to FIGS. 11A and 11B, the coupling hole 240 may include first to third holes 243, 244, and 245. The cathode terminal 131, the anode terminal 132, and the vent portion 140 of the battery cell 100 may be coupled or exposed through the first hole 243, the second hole 244, and the third hole 245, respectively, and the first hole to the third hole 243, 244, and 245 may be alternately provided in the order of the first hole 243, the third hole 245, and the second hole 244 in the longitudinal direction of the guide groove 220.In the case of the first hole 243 and the second hole 244 to which the electrode terminals 131 and 132 of the battery cell 100 are connected, the first hole 243 and the second hole 244 may include a first portion having a first width A 1 and a second portion having a second width A 2 narrower than the first width A 1, as in the above-described embodiment. However, the second portion of the first hole 243 and the second portion of the second hole 244 may be arranged in different directions. For example, the second portion of the first hole 243 may be arranged in the -Y direction based on the drawing, and the second portion of the second hole 244 may be arranged in the +Y direction based on the drawing. A position of the second portion may vary depending on the horizontal rotation direction of the cell group 100G'.Referring to FIGS. 11A and 11B, the one cell group 100G' may vertically move toward the base 210, and the vertical moving operation may be the same as the embodiment illustrated in FIGS. 7A and 7B. In short, in a state where the cathode terminals 131 and the anode terminals 132 of the plurality of battery cells 100 are aligned to correspond to the first portions of the first hole 243 and the second hole 244, respectively, a cell group 100G' may move vertically toward an upper surface of the base 210. In a state where the one cell group 100G' moves vertically, the electrode terminals 131 and 132 may pass through the first portion, and the separation protrusion 133 may be disposed in the first portion.The one cell group 100G' may rotate horizontally in a state where the one cell group 100G' is loosely coupled to the base 210. The horizontal rotation direction may be a counterclockwise direction based on the drawing, which may be a direction in which the second portions of the first hole 243 and the second hole 244 are arranged. That is, by the horizontal rotation of the one cell group 100G', the separation protrusion 133 moves from the first portion to the second portion, and accordingly, a plurality of battery cells 100 can be fixed to the base 210. Moreover, when the one cell group 100G' is rotated horizontally, the vent portion 140 may be completely exposed through the third hole 245.According to an embodiment illustrated in FIGS. 11A and 11B, the cell group 100G' may be aligned to be parallel to the longitudinal direction of the guide groove 220 by the horizontal rotation.In another embodiment, the one cell group 100G' may be fixedly connected to the cell mounting plate 200 and simultaneously electrically connected to the bus bar 320 of the bus bar assembly 300. However, according to another embodiment, the bus bar assembly 300 may have a structure as illustrated in FIGS. 12A and 12B, since a cell group 100G' undergoes the horizontal rotation operation after the vertical movement operation.FIGS. 12A and 12B are perspective views of a bus bar assembly according to another embodiment of the present disclosure.Referring to FIGS. 12A and 12B, a plurality of bus bars 340 may be disposed on a bus bar plate 310. The plurality of bus bars 340 may be disposed on the bus bar plate 310 while being supported by a spring 350, and in one embodiment, the spring 350 may be a Belleville spring elastically deformable in an arc direction. Between the bus bar 340 and the bus bar plate 310, a gap in the height direction (or Z direction) may be formed by the spring 350.The plurality of bus bars 340 may have a width direction (or Y direction) length for the horizontal rotation of the battery cell 100 when assembling the battery cell 100. That is, a fitting groove 341 and an extension portion 342 may be provided in the width direction (or Y direction).Referring to FIGS. 12A and 12B, the plurality of bus bars 340 may include the extension portion 342 on a side in the +Y direction or -Y direction based on the fitting groove 341. For example, the plurality of bus bars 340 may include a first bus bar 340 ain which the extension portion 342 is provided on a side in the +Y direction with respect to the fitting groove 341, and a second bus bar 340 bin which the extension portion 342 is provided on a side in the -Y direction. The first bus bar 340 aand the second bus bar 340 bmay be alternately arranged in the longitudinal direction (or X direction) of the bus bar plate 310, and may be electrically connected to the cathode terminal 131 and the anode terminal 132 of the battery cell 100, respectively, via the fitting protrusion 134. In other words, the one battery cell 100 may be electrically connected to the first bus bar 340 aand the second bus bar 340 b.In another embodiment, as illustrated in FIG. 12B, the first bus bar 340 aand the second bus bar 340 bmay be disposed in a shape inclined in different directions on the bus bar plate 310. For example, the first bus bar 340 amay be disposed in a shape inclined to a side in the +Y direction according to the drawing, and the second bus bar 340 bmay be disposed in a shape inclined to a side in the -Y direction according to the drawing.According to another embodiment of the present disclosure, in the vertical movement, the electrode terminals 131 and 132 of the one cell group 100G' may be inserted into the coupling hole 240 formed in the base 210 and exposed at the bus bar assembly 300 disposed below the bottom of the base 210, and accordingly, the electrode terminals 131 and 132 may be disposed on the bus bar 340. During the vertical movement, since the electrode terminals 131 and 132 are inserted into the first portion having the first width A 1 of the coupling hole 240, the electrode terminals 131 and 132 and the fitting protrusions 134 formed in the electrode terminals 131 and 132 may be disposed in the first portion-facing extension portion 342. Meanwhile, in the vertical movement of a cell group 100G', the spring 350 supporting the bus bar 340 may be compressed, so that the bus bar 340 may be in close contact with the bus bar plate 310.The fitting protrusions 134 of the one cell group 100G' can be inserted into the fitting groove 341 by the horizontal rotation. The one cell group 100G' may move from the first portion to the second portion by the horizontal rotation, so that a combination may be formed between the fitting protrusion 134 and the fitting groove 341. Accordingly, the battery cell 100 may be electrically connected to the bus bar 340 and fixed to the bus bar 340.As described above, the battery cell 100 according to the embodiments of the present disclosure may be simultaneously coupled to the cell fixing plate 200 and the bus bar assembly 300. That is, since the battery cells 100 can be electrically connected to each other without requiring a separate welding operation, the assembly process can be simplified.Although the configurations and features of the present disclosure have been described based on the embodiment of the present disclosure, the present disclosure is not limited thereto, and it will be apparent to those skilled in the art to which the present disclosure pertains that various changes or modifications can be made within the concept and scope of application of the present disclosure that fall within the appended claims.

Claims

A battery pack, comprising: a plurality of battery cells including electrode terminals on a side of a housing; a cell fixing plate to which the plurality of battery cells are coupled; and a bus bar assembly electrically connected to the plurality of battery cells, wherein the cell fixing plate is disposed below the plurality of battery cells and the bus bar assembly is disposed below the cell fixing plate.The battery pack according to claim 1, wherein the bus bar assembly comprises: a plurality of bus bars electrically connected to the electrode terminals; a bus bar plate on which the plurality of bus bars are disposed; and a spring elastically supporting the plurality of bus bars.The battery pack according to claim 2, wherein the bus bar assembly comprises: a fitting groove to which the electrode terminal is coupled; and an extension portion extending in the longitudinal direction or the width direction of the bus bar plate based on the attachment groove.The battery pack according to claim 3, wherein the electrode terminal has a fitting protrusion inserted into the fitting groove, and the plurality of battery cells are electrically connected to the plurality of bus bars when the fitting protrusion is coupled to the fitting groove.The battery pack according to claim 4, wherein the fitting protrusion has a semicircular cross-sectional shape.The battery pack of claim 2, wherein the spring is one of a compression spring and a disk spring.The battery pack of claim 3, wherein the cell mounting plate comprises: a base; and a plurality of coupling holes formed in the base and comprising a first hole into which a cathode terminal is inserted among the electrode terminals and a second hole into which an anode terminal is inserted among the electrode terminals, wherein the first hole and the second hole comprise a first portion having a first width and a second portion having a second width narrower than the first width.The battery pack according to claim 7, wherein the bus bar assembly is disposed such that the extension portion faces the first portion and the fitting groove faces the second portion.The battery pack of claim 7, wherein the plurality of battery cells include a cover plate coupled to a side of the case and provided with the electrode terminal; and a separation protrusion separating a surface of the electrode terminal from the cover plate, wherein the electrode terminal is formed to have a width not greater than the first width, and the separation protrusion is formed to have a width equal to the second width.The battery pack of claim 7, wherein the plurality of battery cells include a cover plate coupled to a side of the case and provided with the electrode terminal; and a coupling protrusion formed on a side of the cathode terminal and a side of the anode terminal, respectively, and passing through the first hole and the second hole, and wherein the coupling protrusion includes a portion shaped to have a width not greater than the first width and a portion shaped to have a width equal to the second width.A bus bar assembly comprising: a plurality of bus bars disposed on a bottom plate of the pack case and electrically connected to electrode terminals of a plurality of battery cells; a bus bar plate on which the plurality of bus bars is disposed; and a spring elastically supporting the plurality of bus bars.The bus bar assembly according to claim 11, wherein the plurality of bus bars include: a fitting groove into which the electrode terminal is fitted; and an extension portion extending in the longitudinal direction or width direction of the bus bar plate with respect to the fitting groove.

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