BATTERY MODULE ASSEMBLY

[0001] The present invention relates to a battery module assembly and, more particularly, to a battery module assembly including unit modules, each of which is configured such that unit cells are loaded in a cartridge in a state in which the unit cells are electrically connected to each other via a bus bar, the battery module assembly including two or more sub modules arranged in a lateral direction, each of the sub modules including two or more unit modules stacked from a ground in a vertical direction, a base plate on which the sub modules are loaded, side cover plates mounted at sides of the sub modules, an upper cover plate loaded on tops of the sub modules, the upper cover plate being fastened and coupled to the sub modules and the side cover plates, a front cover plate mounted at a front of the battery module assembly at which external input and output terminals of the sub modules are located, the front cover plate being fastened and coupled to the sub modules, the base plate, and the side cover plates, a main bus bar for fixing front ends of the sub modules to each other and connecting the external input and output terminals of the sub modules, and a bracket for fixing rear ends of the sub modules to each other.

[0002] Secondary batteries have attracted considerable attention as an energy source for electric vehicles and hybrid electric vehicles, which have been developed to solve problems, such as air pollution, caused by existing gasoline and diesel vehicles using fossil fuel. In addition, the secondary batteries have started to be used as a main component of a power storage device. Therefore, the secondary batteries are being applied to an increasing number of applications owing to advantages thereof and, in the future, the secondary batteries are expected to be applied to even more applications and products.

[0003] As applications and products, to which the secondary batteries are applicable, are increased, kinds of batteries are also increased such that the batteries can provide outputs and capacities corresponding to the various applications and products. In addition, there is a strong need to reduce the size and weight of the batteries applied to the corresponding applications and products.

[0004] For example, small-sized mobile devices, such as a mobile phone, a personal digital assistant (PDA), a digital camera, and a laptop computer, use one or several small-sized, lightweight battery cells for each device according to the reduction in size and weight of the corresponding products. On the other hand, middle or large-sized devices, such as an electric vehicle, a hybrid electric vehicle, and a power storage device, use a middle or large-sized battery module or battery pack having a plurality of battery cells electrically connected with each other because high output and large capacity are necessary for the middle or large-sized devices. The size and weight of a battery module is directly related to an accommodation space and output of a corresponding middle or large-sized device. For this reason, manufacturers are trying to manufacture small-sized, lightweight battery modules.

[0005] Meanwhile, a conventional middle or large-sized battery module is manufactured by stacking a plurality of unit bodies, adding fixing plates to the top and the bottom of the stack of the unit bodies to fix the unit bodies, and fixing the stack of the unit bodies in a frame. In this case, however, overall volume of the battery module is increased. In addition, in a case in which an individual plate is provided to fix each of the unit bodies, overall rigidity of the battery module is reduced. For this reason, it is necessary to provide an additional reinforcing member. Furthermore, in a case in which an additional cooling channel or a cooling member is further loaded for cooling the battery module, the number of parts constituting the battery module is increased and it is difficult to efficiently perform works in a limited space.

[0006] Therefore, there is a high necessity for technology that is capable of fundamentally solving the above problems.

[0007] The present invention has been made to solve the above problems and other technical problems that have yet to be resolved.

[0008] As a result of a variety of extensive and intensive studies and experiments to solve the problems as described above, the inventors of the present application have developed a battery module assembly configured to have a structure in which sub modules are fixed by side cover plates, a main bus bar, and a bracket each having a specific structure, whereby rigidity of the battery module assembly is increased while the increase in volume of the battery module assembly is restrained and, in addition, a uniform cooling effect of the battery module assembly is achieved.

[0009] Therefore, it is an object of the present invention to provide a battery module assembly which can be assembled to have a compact structure and does not need additional parts for improving stability and cooling efficiency of battery modules, whereby stability of battery module assembly is improved while the structure of the battery module assembly is compact and, in addition, production efficiency of the battery module assembly is improved.

[0010] In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a battery module assembly including unit modules, each of which is configured such that unit cells are loaded in a cartridge in a state in which the unit cells are electrically connected to each other via a bus bar, the battery module assembly including two or more sub modules arranged in a lateral direction, each of the sub modules including two or more unit modules stacked from a ground in a vertical direction, a base plate on which the sub modules are loaded, side cover plates mounted at sides of the sub modules, an upper cover plate loaded on tops of the sub modules, the upper cover plate being fastened and coupled to the sub modules and the side cover plates, a front cover plate mounted at a front of the battery module assembly at which external input and output terminals of the sub modules are located, the front cover plate being fastened and coupled to the sub modules, the base plate, and the side cover plates, a main bus bar for fixing front ends of the sub modules to each other and connecting the external input and output terminals of the sub modules, and a bracket for fixing rear ends of the sub modules to each other.

[0011] As described above, the battery module assembly according to the present invention is configured to have a structure in which the sub modules are fixed by the side cover plates, the main bus bar, and the bracket each having a specific structure, whereby rigidity of the battery module assembly is increased while the increase in volume of the battery module assembly is restrained and, in addition, a uniform cooling effect of the battery module assembly is achieved.

[0012] In addition, the battery module assembly according to the present invention does not need additional parts for improving stability and cooling efficiency of battery modules during the manufacture of the battery module assembly, whereby the battery module assembly has a compact structure and, in addition, production efficiency of the battery module assembly is improved.

[0013] In a concrete example, each of the unit cells may be a plate-shaped battery cell or a structure in which two or more plate-shaped battery cells mounted in a cell cover in a state in which electrode terminals of the battery cells are exposed. In a concrete example, the cell cover may include a pair of sheathing members coupled to each other for covering outer surfaces of the battery cells excluding the electrode terminals of the battery cells.

[0014] In addition, the battery cell may be a prismatic secondary battery or a pouch-shaped secondary battery.

[0015] The prismatic secondary battery may be configured to have a structure in which an electrode assembly is mounted in a prismatic metal case in a sealed state and the pouch-shaped secondary battery may be configured to have a structure in which an electrode assembly is mounted in a laminate sheet including a resin layer and a metal layer in a sealed state.

[0016] Specifically, the secondary battery may be a lithium secondary battery exhibiting high energy density, discharge voltage, and output stability. Other components of the lithium secondary battery will hereinafter be described in detail.

[0017] In general, the lithium secondary battery includes a cathode, an anode, a separator, and a non-aqueous electrolytic solution containing lithium salt.

[0018] The cathode may be manufactured, for example, by applying a mixture of a cathode active material, a conductive material, and a binder to a cathode current collector and drying the applied mixture. A filler may be further added as needed. On the other hand, the anode may be manufactured by applying a mixture of an anode active material and a binder to an anode current collector and drying the applied mixture. The above-mentioned ingredients may be further included as needed.

[0019] The separator is disposed between the anode and the cathode. The separator may be made of an insulative thin film exhibiting high ion permeability and mechanical strength.

[0020] The non-aqueous electrolytic solution containing lithium salt consists of a non-aqueous electrolyte and lithium salt. A liquid non-aqueous electrolytic solution, a solid electrolyte, or an inorganic solid electrolyte may be used as the non-aqueous electrolyte.

[0021] The current collectors, the electrode active materials, the conductive material, the binder, the filler, the separator, the electrolytic solution, and the lithium salt are well known in the art to which the present invention pertains and, therefore, a detailed description thereof will be omitted.

[0022] The lithium secondary battery may be manufactured using an ordinary method well known in the art to which the present invention pertains. That is, the lithium secondary battery may be manufactured by disposing a porous separator between a cathode and an anode and injecting an electrolytic solution thereinto.

[0023] The cathode may be manufactured, for example, by applying a slurry containing a lithium transition metal oxide active material, a conductive material, and a binder to a current collector and drying the applied slurry. In the same manner, the anode may be manufactured, for example, by applying a slurry containing a carbon active material, a conductive material, and a binder to a thin current collector and drying the applied slurry.

[0024] In a battery cell assembly, which may be an example of each of the unit cells, the cell cover may include a pair of sheathing members coupled to each other for covering outer surfaces of the battery cells excluding the electrode terminals of the battery cells. For example, two battery cells may be mounted in the cell cover. The two battery cells may be stacked such that the same-polarity electrode terminals of the battery cells are connected in parallel to each other while abutting on each other to constitute a battery cell assembly.

[0025] In a concrete example, the unit cells in each of the unit modules may be connected in parallel to each other.

[0026] Specifically, the unit cells may be mounted on the cartridge such that electrode terminals of the unit cells face each other and the electrode terminals of the unit cells may be connected in parallel to each other by bus bars for connection between battery cells mounted at the cartridge.

[0027] The cartridge is an electrically insulative member exhibiting predetermined rigidity. The cartridge protects the unit cells from external impact and secures stable mounting of the unit cells. In addition, the unit cells are arranged such that the electrode terminals of the unit cells face each other by the cartridge. Consequently, it is possible to more easily achieve electrical parallel connection between the unit cells via bus bars.

[0028] A fixing member may be mounted between electrode terminal connection parts of the unit cells for fixing the electrode terminal connection parts to the cartridge in position. In a concrete example, the fixing member may include an electrically insulative protruding part having an outer shape corresponding to a shape between the electrode terminal connection parts, the protruding part having a through hole formed at a middle region thereof, the protruding part being mounted on the cartridge, and a fastening part inserted through the through hole for coupling the protruding part to the cartridge.

[0029] Even when external impact is applied, therefore, the unit cells can be stably mounted and fixed to the cartridge.

[0030] In addition, each of the cartridges may be provided at opposite sides thereof with protruding parts having fastening holes and the cartridges may be coupled to each other by fastening members inserted through the fastening holes to constitute each of the sub modules. Consequently, the unit cells are fixed by each of the cartridges and, at the same time, the cartridges are fastened and coupled to each other through the fastening holes, thereby achieving a more secure and stable fixing effect. The fastening between the cartridges through the fastening holes may be achieved using, for example, bolts or rivets inserted through the fastening holes. However, the present invention is not limited thereto.

[0031] In a concrete example, one side end of a region of the bus bar for connection between the unit modules to which the electrode terminals are coupled may be bent upward or downward and the bent one side end may be coupled to a connection member for achieving electrical connection with an adjacent one of the unit modules.

[0032] In addition, the unit modules in each of the sub modules are connected in series or in parallel to each other. For example, the connection members may be mounted at the same positions and the stacked structure of the unit modules may be changed to achieve parallel connection.

[0033] In a concrete example, each of the side cover plates may be provided with one or more coolant introduction holes for allowing a coolant to be introduced therethrough.

[0034] In addition, the unit modules in each of the sub modules may be stacked such that a coolant flow channel is formed at a stacked interface between the unit modules and the sub modules may be arranged such that the sub modules are spaced apart from each other to provide a coolant flow channel.

[0035] In a concrete example, each of the side cover plates, which may be a member mounted at a side of a corresponding one of the sub modules such that the sub modules can be mounted and fixed to the base plate and the upper cover plate, may include a body part for covering a side of a corresponding one of the sub modules, bent parts formed at opposite ends of the body part, the bent parts being bent and extend such that the bent parts cover a corresponding one of the sub modules, the bent parts being fastened and fixed to a corresponding one of the sub modules, and a handle formed at one side end of the body part. The body part may be provided with coolant introduction holes.

[0036] In addition, the main bus bar, which may be a member for connecting the external input and output terminals formed at the sub modules to each other and, at the same time, fixing the sub modules to each other such that a predetermined space is maintained between the sub modules, may include a plate-shaped body part, fixing parts, and an opening formed through a middle region of the body part. The fixing parts may be provided with fastening holes, through which the fixing parts are fastened and fixed to the external input and output terminals of the sub modules.

[0037] The bracket may be provided with a coolant discharge hole communicating with the coolant flow channel. A fan or a discharge duct may be mounted in the coolant discharge hole.

[0038] In a concrete example, the bracket, which may be a member for fixing the sub modules to each other such that a predetermined space is maintained between the sub modules in the same manner as in the main bus bar, may include a plate-shaped body part, fixing parts, and a coolant discharge hole formed through a middle region of the body part. The body part may be provided at each end thereof with concavo-convex part having a shape corresponding to a rear concavo-convex structure of each of the sub modules and the fixing parts may be provided with fastening holes, through which the fixing parts are fastened and fixed to rears of the sub modules.

[0039] In the battery module assembly as described above, the coolant flow channel is formed at the stacked interface between the unit modules, the coolant introduction hole, through which a coolant is supplied to the coolant flow channel, is formed at each of the side cover plates, and the coolant discharge hole, through which the coolant is discharged after the coolant cools the unit modules, is formed at the bracket located at the rears of the respective sub modules, whereby it is possible to uniformly cool the unit modules constituting the battery module assembly. Consequently, it is possible to achieve an overall cooling effect of the battery module assembly through improved efficiency.

[0040] For example, the upper cover plate and the base plate each may be made of a sheet exhibiting predetermined rigidity and elasticity. In this case, each of the sub modules may be integrated into a single body and may be protected from external impact.

[0041] The upper cover plate and the base plate are not particularly restricted so long as the upper cover plate and the base plate can be manufactured by machining. In a concrete example, the upper cover plate and the base plate may be manufactured by press forming.

[0042] In addition, the upper cover plate and the base plate each may be provided at the outer surface thereof with reinforcing beads configured to have a concavo-convex structure for improving rigidity of the upper cover plate and the base plate.

[0043] According to circumstances, the upper cover plate and the base plate may be further provided with fastening holes, through which the upper cover plate and the base plate are fastened and coupled to the sub modules.

[0044] Consequently, the sub modules are fastened and fixed to the upper cover plate and the base plate and, therefore, it is possible to achieve a more secure and stable fixing effect. In addition, the fastening of the sub modules to the upper cover plate and the base plate through the fastening holes may be achieved using, for example, bolts or rivets. However, the present invention is not limited thereto.

[0045] In accordance with another aspect of the present invention, there is provided a device including the battery module assembly with the above-stated construction as a power source. Specifically, the device may be an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, a power storage device, a power supply for emergency, a power supply for computer rooms, a portable power supply, a power supply for medical facilities, a power supply for fire extinguishing facilities, a power supply for alarm facilities, or a power supply for refuge facilities. However, the present invention is not limited thereto.

[0046] The structure and manufacturing method of the device are well known in the art to which the present invention pertains and, therefore, a detailed description thereof will be omitted.

[0047] As is apparent from the above description, the battery module assembly according to the present invention is configured to have a structure in which the sub modules are fixed by the side cover plates, the main bus bar, and the bracket each having a specific structure, whereby rigidity of the battery module assembly is increased while the increase in volume of the battery module assembly is restrained and, in addition, a uniform cooling effect of the battery module assembly is achieved. In addition, the battery module assembly according to the present invention can be assembled to have a compact structure does not need additional parts for improving stability and cooling efficiency of battery modules, whereby the battery module assembly has a compact structure and, in addition, production efficiency of the battery module assembly is improved.

[0064] Now, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted, however, that the scope of the present invention is not limited by the illustrated embodiments.

[0065] FIG. 1 is a perspective view showing a pouch-shaped battery cell according to the present invention.

[0066] Referring to FIG. 1, a battery cell 20 is a plate-shaped battery cell 20 having electrode terminals (a cathode terminal 21 and an anode terminal 22) formed at one side end thereof. Specifically, the plate-shaped battery cell 20 is configured to have a structure in which an electrode assembly (not shown) is mounted in a pouch-shaped battery case 23 made of a laminate sheet including a metal layer (not shown) and a resin layer (not shown) and a sealed part 24 is formed by, for example, thermal bonding. The plate-shaped battery cell 20 may be generally referred to as a ‘pouch-shaped battery cell.’

[0067] FIG. 2 is a perspective view showing a unit cell configured to have a structure in which battery cells, one of which is shown in FIG. 1, are mounted in cell covers.

[0068] Referring to FIG. 2 together with FIG. 1, two battery cells 20 are received and fixed in cell covers 111 and 112 including an upper cell cover 111 and a lower cell cover 112. In addition, electrode terminals 21 and 22 of the two battery cells 20 are exposed from one side ends of the cell covers such that the electrode terminals 21 and 22 of the two battery cells 20 are electrically connected in parallel to each other to form two electrode terminals 110a and 110b.

[0069] FIG. 3 is a perspective view showing a unit module configured to have a structure in which unit cells, one of which is shown in FIG. 2, are mounted in a cartridge. FIGS. 4 and 5 are a plan view and a side view showing a unit module according to the present invention, respectively.

[0070] Referring to these drawings, two unit cells 110 are mounted in a cartridge 120 to constitute one unit module 100. At this time, the two unit cells 110 are arranged such that the cathode terminal 110a and the anode terminals 110b of one of the unit cells 110 face the cathode terminal 110a and the anode terminal 110b of the other unit cell 100, respectively. In addition, the cathode terminals 110a of the unit cells are electrically connected in parallel to each other via a bus bar 130 and the anode terminals 110b of the unit cells are electrically connected in parallel to each other via another bus bar 130.

[0071] Specifically, the bus bars 130 are electrically coupled to the electrode terminals 110a and 110b. Each of the bus bars 130 is provided at one side end thereof with a bent part 131, which is bent downward. The bent part 131 has a fastening hole 132. The fastening hole 132 is used for electrical connection between unit modules 100 when the unit modules 100 are stacked (see FIGS. 6 and 7).

[0072] In addition, the cartridge 120 is provided at opposite sides thereof with protruding parts 121, each of which has a fastening hole 122. The unit modules 100 may be coupled to each other by fastening members 123 (see FIG. 5) inserted through the fastening holes 122 of the protruding parts 121.

[0073] Each of the protruding parts 121 has a height 110 to 150% greater than the height of the cartridge 120. When the unit modules 100 are stacked, therefore, a predetermined gap 170 (see FIG. 9) is formed at a stacked interface between the unit modules 100. The gap 170 (see FIG. 9) may be used as a coolant flow channel, along which a coolant flows.

[0074] FIG. 6 is a perspective view showing a shape in which unit modules according to the present invention are stacked.

[0075] Referring to FIG. 6, unit modules 100 are vertically stacked from the ground to constitute one sub module 200. Specifically, the unit modules 100 are vertically stacked and then fastening members 123 are inserted through the protruding parts formed at opposite sides of the unit modules 100 such that the unit modules 100 are coupled to each other.

[0076] FIG. 7 is a partially enlarged view of FIG. 6 and FIG. 8 is a perspective view showing a shape in which connection parts 140 and bus bars 151 and 152 for external input and output terminals are mounted at a sub module 200 according to the present invention.

[0077] Referring to these drawings, the unit modules 100 are electrically connected in series to each other via the connection parts 140. In addition, the bus bars 151 and 152 for external input and output terminals are mounted at the series-connected unit modules 100 such that the unit modules 100 can be electrically connected to external input and output terminals 161 and 162 via the bus bars 151 and 152 for external input and output terminals.

[0078] FIG. 9 is a perspective view showing a shape in which an external input and output terminal protection member and a series connection member protection member are mounted at the sub module of FIG. 8.

[0079] Referring to FIG. 9 together with FIG. 8, an external input and output terminal protection member 165 is mounted at the external input and output terminal 161 of the sub module 200 for protecting the external input and output terminal 161 from the outside. In addition, a series connection member protection member 145 is mounted at the series connection parts 140, via which the unit modules 100 are electrically connected in series to each other, for protecting the series connection parts 140.

[0080] FIG. 10 is a side view of FIG. 9.

[0081] Referring to FIG. 10 together with FIG. 5, predetermined gaps 170 may be formed at stacked interfaces between the respective unit modules 100 constituting the sub module 200. The gaps 170 may be used as coolant flow channels, along which a coolant flows.

[0082] FIG. 11 is a perspective view showing a shape in which a side cover plate is mounted at the sub module of FIG. 9.

[0083] Referring to FIG. 11, a side cover plate 300 includes a body part 310 for covering one side of the sub module 200. The body part 310 is provided with coolant introduction holes 311, through which a coolant is introduced into the sub module 200 from the outside. In addition, the body part 310 is provided at opposite ends thereof with bent parts 320, which are bent and extend such that the bent parts 320 cover the sub module 200.

[0084] In addition, fixing parts 312 and 321, which are fastened and fixed to the sub module 200, are formed at the body part 310 and the bent parts 320 of the side cover plate 300. A handle 330 is formed at one side end of the body part 310.

[0085] FIG. 12 is a perspective view showing a shape in which two sub modules are fixed by side cover plates and a bracket.

[0086] Referring to FIG. 12, two sub modules 200 are coupled to each other by a bracket 500 mounted at rears of the sub modules.

[0087] Specifically, the bracket 500 includes a plate-shaped body part 510, fixing parts 520, and a coolant discharge hole 530 formed through a middle region of the body part 510.

[0088] In addition, the body part 510 is provided at each end thereof with concavo-convex part 511 having a shape corresponding to a rear concavo-convex structure of each of the sub modules 200. The fixing parts 520 are provided with fastening holes, through which the fixing parts may be fastened and fixed to the rears of the sub modules 200.

[0089] FIG. 13 is a plan view of FIG. 12.

[0090] Referring to FIG. 13, coolant flow channels (see arrows), along which a coolant flows, are formed in a middle part of each of the sub modules 200 by the bracket 500 mounted at the rears of the sub modules 200 and a main bus bar 400 (see FIG. 14) mounted at the fronts of the sub modules 200. Consequently, the coolant may be introduced into the sub modules 200 through the side cover plates 300 to cool battery cells (not shown) mounted in the sub modules 200, flow along the middle coolant flow channels, and then discharged out of the sub modules 200 through the coolant discharge hole 530 formed at the bracket 500.

[0091] According to circumstances, a fan (not shown) or a discharge duct (not shown) may be mounted in the coolant discharge hole 530 to further improve cooling efficiency.

[0092] FIG. 14 is a perspective view showing a shape in which the two sub modules are fixed by a main bus bar in a state in which the two sub modules are electrically connected to each other by the main bus bar and a base plate, an upper cover plate, and a front cover plate are mounted at the sub modules.

[0093] Referring to FIG. 14, the external input and output terminals 162 and 161 of the two sub modules 200 are electrically connected in series to each other via a main bus bar 400. In addition, the two sub modules 200 are fixed by the main bud bar 400 such that the two sub modules 200 are spaced apart from each other by a predetermined distance.

[0094] In addition, in a state in which the two sub modules 200 are loaded on a base plate 600, the tops of the two sub modules 200 are protected by an upper cover plate 700 and the fronts of the two sub modules 200 are protected by a front cover plate 800.

[0095] FIG. 15 is a perspective view showing a battery module assembly according to the present invention.

[0096] Referring to FIG. 15 together with FIG. 14, reinforcing beads 750 and 650 configured to have a concavo-convex structure for improving rigidity of the upper cover plate 700 and the base plate 600 are formed at the outer surfaces of the upper cover plate 700 and the base plate 600.

[0097] Although the exemplary embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.