Battery Pack and Device Including the Same

A battery pack according to an embodiment of the present disclosure can includes a battery cell assembly of stacked battery cell units. The battery cell assembly can be mounted on a pack tray. A pack cross beam can be located on a side surface of the battery cell assembly on the pack tray and provided with an internal gas passage. A venting unit can be located on an upper part of the battery cell assembly. The battery cell unit can include at least one battery cell and a cell cover to partially surround the battery cell. The cell cover can include at least one venting part. The venting unit can include a plurality of venting channels to guide a gas from the venting unit to the gas passage. Each venting channel can be aligned to a corresponding battery cell unit.

TECHNICAL FIELD

The present disclosure relates to a battery pack and a device including the same, and more particularly, to a cell-to-pack (CTP) type battery pack that allows venting gas to be discharged outside the battery pack along a specific path when a thermal event occurs, thereby minimizing the thermal runaway transition inside the battery pack and preventing structural collapse, and a device including the same.

BACKGROUND

Currently, the secondary battery has been widely used as an energy source for wireless mobile devices or wearable devices, which are small multifunctional products, and has also been used as an energy source for electric vehicles and hybrid electric vehicles presented as alternatives to existing gasoline and diesel vehicles or as an energy storage system (ESS).

Generally, secondary batteries have an operating voltage of approximately 2.5V to 4.5V per one battery. Therefore, in the case of electric vehicles or energy storage systems that require large capacity and high output, a battery module in which a plurality of secondary batteries are connected in series and/or in parallel, and a battery pack in which the battery modules are connected in series and/or in parallel are used as energy sources. In other words, a conventional battery pack includes a battery module as the subordinate concept, and the battery module includes battery cells as the subordinate concept. Additionally, the number of battery cells included in the battery module or the number of battery modules included in the battery pack can be variously determined depending on the output or capacity of the battery pack required for the electric vehicle.

On the other hand, conventional battery packs may be disadvantageous in terms of energy density. Typically, in the process of housing a plurality of battery cells in a module case and modularizing them, due to several components such as module cases or stacking frames, the volume and weight of the battery pack may be unnecessarily increased, or the space occupied by the battery cells may be reduced. Furthermore, not only the space occupied by the components themselves, such as module cases and stacking frames, but also the housing space of the battery cells may be reduced in order to ensure assembly tolerances for these components. Therefore, in the case of conventional battery packs, it may generate a limit for enhancing the energy density.

Additionally, in the case of conventional battery packs, one of the typically important issues is safety. In particular, when a thermal event occurs in one of the multiple battery cells included in the battery pack, it is necessary to block this event from propagating to other battery cells.

If thermal propagation between battery cells is not properly suppressed, this may lead to thermal events in other battery cells included in the battery pack, which causes greater problems such as ignition or explosion of the battery pack. Furthermore, the ignition or explosion occurring in the battery pack can cause great damage to human life or property in the surrounding area. Therefore, such battery packs are required to have a configuration that can appropriately control the above-mentioned thermal events.

DETAILED DESCRIPTION OF THE INVENTION

Technical Problem

It is an object of the present disclosure to provide a CTP type battery pack that eliminates the configuration of the battery module and is assembled in battery cell units, thereby improving the assembly process and energy density of the battery pack.

It is another object of the present disclosure to provide a CTP type battery pack that guides venting gas to move along a preplanned specific path and discharge to the outside of the battery pack in preparation for a thermal event. Accordingly, thermal runaway transition between battery cells within the battery pack can be minimized, and structural collapse of the battery pack can be prevented.

However, the technical problems to be solved by embodiments of the present disclosure are not limited to the above-described problems, and can be variously expanded within the scope of the technical idea included in the present disclosure.

Technical Solution

According to one embodiment of the present disclosure, there is provided a battery pack comprising: a battery cell assembly including a plurality of stacked battery cell units; a pack tray on which the battery cell assembly is mounted; a pack cross beam located on one side surface of the battery cell assembly on the pack tray and provided with a gas passage at its inside; and a venting unit located on an upper part of the battery cell assembly, wherein the battery cell unit comprises at least one battery cell and a cell cover that partially surrounds the at least one battery cell, wherein the cell cover is formed with at least one venting part, wherein the venting unit comprises a plurality of venting channels that guide the gas jetted from the venting unit to the gas passage, and wherein each of the venting channels is located so as to correspond to each of the battery cell units.

Each of the venting channels may have independent venting spaces that are not shared with each other.

The venting channels may be partitioned by a partition wall portion inside the venting unit.

The venting channels may extend along the longitudinal direction of the battery cell units, which is perpendicular to the direction in which the battery cell units are stacked.

Each of the venting channels may communicate with each of the battery cell units on a one-to-one basis.

The cell cover may have a shape in which the lower side is open.

The cell cover may comprise an upper surface part and side surface portions, and at least one venting part may be formed on the upper surface part.

The venting part may have the shape of a hole through which a part of the cell cover passes.

The venting part may a portion of the cell cover which has a weaker stiffness than the portion adjacent thereto, and ruptures when a force or heat exceeding a certain pressure is applied.

The venting unit may comprise inlets that communicate with the venting part.

The inlet may be provided with a mesh structure.

One of the venting unit and the pack cross beam may be formed with a connecting part, and the other may be formed with a connecting hole coupled to the connecting part, and each of the connecting parts may communicate with each of the venting channels on a one-to-one basis.

The connecting parts may be fitted and coupled into the corresponding connecting holes on a one-to-one basis.

A rupture disk having a structure that ruptures at a specific pressure or higher may be provided inside at least one of the connecting part or the connecting hole.

The venting channel may communicate with the gas passage of the pack cross beam via the connecting part and the connecting hole.

The pack cross beam may comprise a plurality of mesh parts that partitions the gas passage, and the mesh parts may be located at each point between the connecting parts along the longitudinal direction of the pack cross beam.

According to another embodiment of the present disclosure, there is provided a device comprising the above-mentioned battery pack.

Advantageous Effects

According to the embodiments of the present disclosure, there can be provided a battery pack that can house battery cells in a pack tray in a space-efficient manner, has higher energy density than conventional battery packs, and has a simplified assembly process.

Also, when a thermal event occurs in a battery cell, the high-temperature venting gas or flame jetted from the battery cells moves along a preplanned specific path and is discharged to the outside of the battery pack. Thereby, thermal runaway transition between battery cells within the battery pack can be minimized and structural collapse of the battery pack can be prevented.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Portions that are irrelevant to the description will be omitted to clearly describe the present disclosure, and same reference numerals designate same or like elements throughout the description.

Further, in the drawings, the size and thickness of each element are arbitrarily illustrated for convenience of description, and the present disclosure is not necessarily limited to those illustrated in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for clarity. In the drawings, for convenience of description, the thicknesses of a part and an area are exaggeratedly illustrated.

Further, it will be understood that when an element such as a layer, film, region, or plate is referred to as being “on” or “above” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, it means that other intervening elements are not present. Further, a certain part being located “above” or “on” a reference portion means the certain part being located above or below the reference portion and does not particularly mean the certain part “above” or “on” toward an opposite direction of gravity.

Further, throughout the description, when a portion is referred to as “including” or “comprising” a certain component, it means that the portion can further include other components, without excluding the other components, unless otherwise stated.

Further, throughout the description, when it is referred to as “planar”, it means when a target portion is viewed from the upper side, and when it is referred to as “cross-sectional”, it means when a target portion is viewed from the side of a cross section cut vertically.

FIG.1is a perspective view showing a part of a battery pack according to an embodiment of the present disclosure.FIG.2is a perspective view showing a state in which the venting unit is removed from the battery pack ofFIG.1.FIG.3is a perspective view showing a battery cell assembly and a venting unit according to an embodiment of the present disclosure.FIG.4is an exploded perspective view of the battery cell assembly ofFIG.3.

Referring toFIGS.1to4, a battery pack1000according to an embodiment of the present disclosure comprises a battery cell assembly100A including a plurality of stacked battery cell units100; a pack tray1100on which the battery cell assembly100A is mounted; a pack cross beam1200located on one side surface of the battery cell assembly100A on the pack tray1100and provided with a gas passage at its inside; and a venting unit400located on an upper part of the battery cell assembly100A.

The pack tray1100comprises a space in which the battery cell assembly100A is seated, and the battery cell assembly100A can be accommodated in the seating space of the pack tray1100. The pack tray1100may in the form of a box having an open upper end. That is, the pack tray1100may include a bottom part1100F and a side wall part1100S extending vertically from one corner of the bottom part1100F, and the battery cell assembly100A can be accommodated in a seating space formed by the bottom part1100F and the side wall part1100S. Meanwhile, although not specifically illustrated, the battery pack1000according to this embodiment may further include a pack cover that covers the open upper part of the pack tray1100.

The battery pack1000according to this embodiment may comprise a pack cross beam1200that partitions the seating space described above. The battery cell assembly100A mounted in the seating space can be prevented from being spaced apart by the pack cross beam1200. Further, the battery pack1000according to this embodiment may include a pack side beam1500disposed on the other side surface of the battery cell assembly100A. Forward/backward and right/left movement of the battery cell assembly100A can be minimized by the pack cross beam1200and the pack side beam1500, thereby preventing damage of the battery cell assembly100A due to external vibration and impact. A gas passage is provided inside the pack cross beam1200, which will be described later.

The pack cross beam1200may be configured to extend along a direction in which the battery cell units100are stacked within the battery cell assembly100A, and the pack side beam1500may be configured to extend along a direction perpendicular to the direction in which the battery cell units100are stacked within the battery cell assembly100A. For example, as shown inFIG.2, the battery cell units100may be stacked along a direction parallel to the Y axis, the pack cross beam1200may extend along a direction parallel to this Y-axis, and the pack side beam1500may extend along a direction parallel to the X-axis, which is perpendicular to the Y-axis. At this time, the direction perpendicular to the direction in which the battery cell units100are stacked corresponds to the longitudinal direction of the battery cell unit100, and the longitudinal direction of the battery cell unit100may be parallel to the X-axis.

The pack cross beam1200and the pack side beam1500may be arranged so as to be spaced apart from each other or arranged so as to intersect each other to form the plurality of seating spaces. As a specific example, the battery cell assembly100A may be arranged in two rows inside the pack tray1100, and the pack cross beam1200may be arranged across the central part of the pack tray1100to separate the battery cell assemblies100A arranged in two rows. The pack side beam1500is arranged perpendicular to the pack cross beam1200so as to separate the battery cell assemblies100A arranged in each row, and may be arranged in plural numbers at regular intervals. However, this is an example of the internal structure of the battery pack1000, and the structure of the battery pack1000of the present embodiment is not limited to the examples mentioned above.

On the other hand, as mentioned above, the battery cell assembly100A of this embodiment may be provided in a state where a separate frame protecting the outer surfaces of the battery cell units100is minimized. That is, the battery cell assembly100A of the present embodiment may have a module-less structure. Here, the module-less structure may refer to a cell-to-pack structure in which the battery cell structure is directly coupled to the battery pack structure without a module frame.

Typically, conventional battery packs1000have a double assembly structure in which a plurality of battery cells and several components connected thereto are assembled to form a battery module, and the plurality of battery modules are housed in the battery pack1000again. At this time, since the battery module comprises a module frame or the like that forms its outer surface, conventional battery cells are doubly protected by the module frame of the battery module and the pack tray1100of the battery pack1000. However, such a double assembly structure not only increases the manufacturing unit cost and the manufacturing process of the battery pack1000, but also has a disadvantage that reassembly performance is deteriorated when defects occur in some battery cells. Further, when the cooling member or the like exists outside the battery module, there is a problem that a heat transfer path between the battery cell and the cooling member becomes slightly complicated.

Thus, the unit module mounted on the battery pack1000in the present embodiment can be provided in the form of a ‘battery cell assembly’ in which the module frame is omitted. Thereby, the structure of the battery pack1000can be simplified, advantages in terms of manufacturing cost and manufacturing process can be obtained, and the effect of weight reduction of the battery pack1000can be achieved.

In the case of this embodiment, there is no need to further provide a module case, a stacking frame, or fastening members such as bolts for maintaining the stacked state of the battery cells, as in conventional battery modules or battery packs. That is, in this embodiment, as the space occupied by the component is removed, the battery cell can occupy more space, thereby further improving the energy density, reducing the overall volume and weight, and simplifying the manufacturing process.

Next, the battery cell assembly, the battery cell unit, and the battery cell according to this embodiment will be described in detail.

FIG.5is a perspective view showing one of the battery cell units included in the battery cell assembly ofFIGS.3and4.FIG.6is an exploded perspective view of the battery cell unit ofFIG.5.FIG.7is a diagram showing a battery cell included in the battery cell unit ofFIG.6.

Referring toFIGS.4to7together, the battery cell assembly100A according to an embodiment of the present disclosure includes a plurality of battery cell units100stacked along one direction. The battery cell unit100according to an embodiment of the present disclosure includes at least one battery cell110, and a cell cover200that partially surrounds the at least one battery cell110.

The battery cell110according to the present embodiment may be various types of battery cells, for example, a pouch-type battery cell, a prismatic battery cell, or a cylindrical battery cell. In one example, as shown inFIG.7, the battery cell110according to the present embodiment may be a pouch-type battery cell. Below, a pouch-type battery cell will be described, but the battery cell110according to this embodiment is not limited thereto, and various types of battery cells can be applied.

The battery cell110according to the present embodiment may have a shape in which an electrode assembly having electrode leads111protruding in one direction or in both directions is housed in a pouch case114. Such a battery cell110may have a rectangular sheet shape. The battery cell110can be formed by housing an electrode assembly in a pouch case114made of a laminated sheet including a resin layer and a metal layer and then bonding the outer periphery of the pouch case114. As an example, the battery cell110may have a structure in which two electrode leads111face each other and protrude from one end part114aand the other end part114bof the cell body113, respectively. In another embodiment, a structure in which the electrode leads111of the battery cells110all protrude in one direction is also possible. One of the electrode leads111is a cathode lead, and the other is an anode lead.

The battery cell110can be produced by joining both ends114aand114bof a pouch case114and one side part114cconnecting them in a state in which an electrode assembly (not shown) is housed in a pouch case114. In other words, the battery cell110according to an embodiment of the present disclosure has a total of three sealing parts114s, wherein the sealing parts114shave a structure that is sealed by a method such as thermal fusion, and the remaining other side part may be composed of a folding part115. That is, the battery cell110according to the present embodiment may be a pouch-type secondary battery in which the electrode assembly is housed inside the pouch case114and the outer periphery of the pouch case114is sealed to form a sealing part114s.FIG.7shows only the case where both end parts114aand114bof the pouch case114is formed with sealing parts114s, and a sealing part is not shown on the side facing the folding part115, but the sealing part on the side facing the folding part115is in a state of being folded to one side after sealing is completed for space utilization.

The pouch case114made of the laminate sheet may include an inner resin layer for sealing, a metal layer to prevent penetration of materials, and an outermost outer resin layer. Based on the electrode assembly inside the pouch case114, the inner resin layer may be located at the innermost side, the outer resin layer may be located at the outermost side, and the metal layer may be located between the inner resin layer and the outer resin layer.

In order to protect the electrode assembly from the outside, the outer resin layer has excellent tensile strength and weather resistance relative to the thickness and may have electrical insulation properties. Such an outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer can prevent air, moisture, and the like from flowing into the pouch-type secondary battery. Such a metal layer can include aluminum (Al). The inner resin layers may be heat-sealed to each other by heat and/or pressure applied in a state where the electrode assembly is embedded. Such an inner resin layer may include casted polypropylene (CPP) or polypropylene (PP).

The pouch case114is divided into two portions, wherein at least one of the two portions may be formed with a concave housing part in which the electrode assembly can be seated. Along the outer periphery of this housing part, the inner resin layers of the two portions of the pouch case114may be joined to each other to provide a sealing part114s. The pouch case can be sealed in this way to manufacture the battery cell110, which is a pouch-type secondary battery.

Within the battery cell unit100, the battery cells110may be comprised of one or more batteries. As an example,FIG.6shows that the battery cell unit100includes three battery cells110. A plurality of battery cells110may be stacked so that they can be electrically connected to each other. In particular, a plurality of battery cells110may be stacked along a direction parallel to the y-axis while standing upright so as to face one surface each of the cell body113. Thereby, the electrode lead111can protrude in a direction perpendicular to the direction in which the battery cells110are stacked. In the battery cell110, one electrode lead111may protrude toward the x-axis direction, and the other electrode lead111may protrude toward the −x-axis direction. In the case of the battery cells in which electrode leads111protrude in only one direction, the electrode leads111may protrude in the x-axis direction or the −x-axis direction.

FIG.8is a perspective view showing a cell cover included in the battery cell unit ofFIG.6.

Referring toFIGS.5to8together, the cell cover200according to this embodiment partially surround at least one battery cell110, as described above. The cell cover200may include a side surface part210and an upper surface part220. The side surface part210may cover one side surface of the battery cell110, and the upper surface part220may cover the upper part of the battery cell110. The cell cover200may include two side surface parts210and one upper surface part220. One surface of the side surface parts210and one surface of the upper surface part220may be perpendicular, and the side surface parts210may extend downward from both opposite sides of the upper surface part220. The cell cover200according to this embodiment may have a shape in which the lower side is open. That is, when the cell cover200is cut along the yz plane inFIG.8, the cell cover200may have an ‘n’ shape. The cell cover200may be provided so as to surround at least a part of three of the remaining four surfaces of the six-sided battery cell110excluding the two surfaces on which the electrode leads111are formed.

The cell cover200can not only delay a thermal runaway phenomenon, but also supplement the stiffness of the battery cell110, so that the battery cell110can maintain an upright state. The cell cover200can cover at least a part of the battery cells110to thereby support the battery cells110, and can stably maintain the stacked state of the battery cells110arranged upright in one direction. More specifically, the side surface parts210of the cell cover200support the side surfaces of the battery cell110, so that the upright state of the battery cells110can be maintained. Moreover, the lower side edge of the cell cover200can be seated on the thermal resin layer1300on the bottom part1100F of the pack tray1100, through which the cell cover200is self-supportable, and the upright state of the battery cells110inside the cell cover200can be maintained.

FIGS.9(a) and (b)are cross-sectional views taken along the cutting line C-C′ ofFIG.8, respectively, which are cross-sectional views showing the embodiments of the present disclosure.

Referring toFIG.8andFIGS.9(a) and (b), the cell cover200according to this embodiment may be formed with at least one venting part200V. The at least one venting part200V may be formed on the upper surface part220of the cell cover200.

When thermal runaway occurs in at least one battery cell110inside the cell cover200to generate high temperature gas and flame, the venting part200V formed in the cell cover200functions as a passage for discharging such high-temperature gas and flame to the venting unit400, which will be described later. As long as efficient discharge of gas and flame is possible, the number and area of the venting part200V provided in one cell cover200are not especially limited. As an example, as shown inFIG.8, and the like, three venting parts200V may be formed on the upper surface part220of the cell cover200, and the area of the venting part200V formed in the center may be slightly larger than the areas of the other venting parts200V.

Conventionally, when ignition occurs in the battery cell110, gas, sparks and the like move in the direction of the electrode lead111, which causes a problem that an additional thermal runaway phenomenon occurs. However, in the present embodiment, the venting part200V is formed in the cell cover200, so that movement of gas and sparks in the direction where the electrode lead111is located can be minimized. The gas discharge path by the venting part200V may be spaced apart from the electrode lead111, and the electrode lead111and the electrical components connected thereto can be prevented from being damaged by gas, sparks, or flames, or the like.

As shown inFIG.9A, the venting part200Va according to an embodiment of the present disclosure may be in the form of a hole that partially penetrates in the upper surface part220of the cell cover200. Alternatively, as shown inFIG.9B, the venting part200Vb according to another embodiment of the present disclosure makes the stiffness of a part of the upper surface part220relatively much weaker than that of the parts adjacent thereto, so that when force or heat above a certain pressure is applied, this part may be the portion to be ruptured.

According to such embodiments, when high-temperature gas or flame blows out from at least one battery cell110surrounded by the cell cover200, high-temperature gas or flame is discharged through the venting part200V, and can be guided into the inside of the venting unit400, which will be described later.

Next, the venting unit400according to the present embodiment will be described in detail.

FIG.10is a perspective view showing a venting unit according to an embodiment of the present disclosure.

Referring toFIGS.2,3,5,6,8and10together, the venting unit400according to the present embodiment is located in the upper part of the battery cell assembly100A. Further, the venting unit400includes a plurality of venting channels410that guide gas jetted from the venting part200V of the cell cover200to the gas passage of the pack cross beam1200, which will be described later, wherein each of the venting channels410is located so as to correspond to each of the battery cell units100. When a thermal event occurs in a battery cell110included in a specific battery cell unit100and high temperature gas is jetted from the battery cell unit100, the venting unit400can guide high-temperature gas so as to flow from the venting part200V of the corresponding battery cell unit100to the inside of the pack cross beam1200.

The venting unit400includes a plurality of venting channels410, which are passages through which gas can move. Each of the venting channels410may have independent venting spaces that are not shared with each other. The venting unit400may include a partition wall part420that partitions the internal space, and the venting channels410may be partitioned by a partition wall part420inside the venting unit400.

The venting unit400may be a box-shaped structure with an internal space, and this internal space may be partitioned by the partition wall part420to provide a venting channel410. The venting channels410are completely closed from each other by the partition wall part420, so they do not share spaces with each other and can have independent venting paths. Thereby, high-temperature gas or flame passing through one venting channel410is not propagated to other adjacent venting channels410.

FIG.11is a cross-sectional view showing a part of the cross section taken along the cutting line A-A′ inFIG.1.FIG.12is a cross-sectional view showing a part of the cross section taken along the cutting line B-B′ inFIG.1.

Referring toFIGS.3,6,8,10,11and12together, the venting unit400according to the present embodiment may include inlets430that communicate with the venting part200V of the battery cell unit100. The inlets430may be formed on the lower surface of the venting unit400, and high-temperature gas and flame discharged through the venting part200V may flow into the inside of the venting channel410through the inlet430.

The venting channel410may extend along the longitudinal direction of the battery cell unit100, which is perpendicular to the direction in which the battery cell units100are stacked. Additionally, each of the venting channels410may communicate with each of the battery cell units100on a one-to-one basis. That is, the number of venting channels410may match the number of battery cell units100in the battery cell assembly100A, and one of the battery cell units100may communicate only with the venting channel410located in the upper part thereof and may not communicate with the other venting channel410.

High-temperature gas and flame generated from one of the battery cell units100are discharged only to the venting channel410communicating therewith, and movement to other venting channels410is restricted. In the battery cell assembly100A according to the present embodiment, the battery cells110are housed in the cell cover200to constitute the battery cell unit100. High-temperature gas or flame resulting from a thermal runaway phenomenon occurring in one of the battery cell units100is blocked by the side surface part210of the cell cover200and cannot propagate to other adjacent battery cell units100. The cell cover200may be made from a material having a high melting point so that it does not melt even during thermal runaway phenomenon. Further, the cell cover200may be made from a material having a mechanical strength exceeding a predetermined range so that it can stably support the battery cell110, thereby protecting the battery cell110from external shocks, etc. Examples of the materials used for the cell cover200include steel, stainless steel (SUS), and the like.

Further, when high-temperature gas or flame is discharged from the upper part of the battery cell unit100to the corresponding venting channel410on a one-to-one basis, each of the venting channels410has independent venting spaces that are not shared with each other, so that high-temperature gas or flame does not flow into other adjacent venting channels410. Therefore, there is no danger of high-temperature gas or flame flowing back into the other adjacent venting channel410and the other battery cell unit100located below it. If the venting spaces of the venting channels410are shared with each other, the battery cell unit100and other adjacent battery cell units100where thermal runaway phenomenon occurred have relatively low internal pressure, whereby there is a risk that the generated high-temperature gas or flame may flow into the inside. In this embodiment, by realizing an independent venting path for each battery cell unit100, thermal runaway transition between battery cells110can be minimized and structural collapse of the battery pack can be prevented.

On the other hand, the inlet430according to the present embodiment may be provided with a mesh structure. The mesh structure may be formed from a metal material. When metal particles contained in high-temperature gas or flame pass through the inlet430, they can be filtered by the mesh structure, and the metal particles can hit against the mesh structure to lower the temperature and reduce the risk of explosion.

On the other hand, according to the present embodiment, the venting unit400and the pack cross beam1200may be connected to each other. Specifically, a connecting part can be formed in any one of the venting unit400and the pack cross beam1200, and a connecting hole coupled to the connecting part may be formed on the other side. For example, as shown inFIG.12, a connecting part440may be formed in the venting unit400, and a connecting hole1220into which the connecting part440is inserted may be formed in the pack cross beam1200. As another embodiment, it is of course possible that the pack cross beam1200is formed with a connecting part, and the venting unit400is formed with a connecting hole into which the connecting part of the pack cross beam1200is inserted.

The connecting part440according to the present embodiment may be in the form of a pipe so as to be inserted and coupled to the connecting hole1220. The connecting parts440may be fitted and coupled to the corresponding connecting holes1220on a one-to-one basis. Additionally, each of the connecting parts440may communicate with each of the venting channels410on a one-to-one basis.

As mentioned above, a gas passage1210is provided inside the pack cross beam1200. That is, the pack cross beam1200may be provided with a hollow structure so as to function as a passage for discharging venting gas to the outside. Through the connection between the connecting part440and the connecting hole1220, the venting channel410of the venting unit400and the gas passage1210in the pack cross beam1200can be communicated with each other. That is, the venting channel410may communicate with the gas passage1210of the pack cross beam1200through the connecting part440and the connecting hole1220.

Accordingly, high-temperature gas or flame moving along the venting channel410moves to the gas passage1210of the pack cross beam1200through the connecting part440and the connecting hole1220, and finally can be discharged to the outside of the battery pack1000. The pack cross beam1200according to this embodiment can not only prevent movement or separation of the battery cell assembly100A, but also can perform a venting function which discharges high-temperature gas and flame generated by the thermal runaway phenomenon of the battery cell unit100to the outside of the battery pack1000.

On the other hand, a rupture disk450having a structure that ruptures at a specific pressure or higher may be provided inside at least one of the connecting part440or the connecting hole1220according to the present embodiment. The specific pressure can be adjusted by the thickness or material of the rupture disk450. In terms of the structure, the rupture disk450is more preferably provided inside the connecting part440. The rupture disk450may be constructed of a membrane structure that ruptures at a specific pressure or higher.

The gas jetted from one of the battery cell units100is guided to flow along the venting channel410corresponding to the battery cell unit100, and the rupture disk450of the connecting part440corresponding to the venting channel410is ruptured by the pressure of the gas, and is thereby discharged into the gas passage1210of the pack cross beam1200. And, as shown inFIG.12, the gas flow in the gas passage1210of the pack cross beam1200does not flow back to the other connecting part440blocked by the rupture disk450, but may be guided in the direction of separate gas exhaust ports (not shown) provided in the pack cross beam1200. That is, the gas exhaust port communicates with the outside air, and other connection parts440are blocked with the rupture disk450, so that the gas flow in the gas passage1210of the pack cross beam1200may be guided directly in the direction of the gas exhaust port. Even within the pack cross beam1200, the independent venting path for each battery cell unit100is maintained, thereby making it possible to prevent thermal runaway transition between battery cells110.

In addition, the pack cross beam1200may include a plurality of mesh parts1230that partition the gas passage1210, and the mesh parts1230may be located at each point between the connecting parts440along the longitudinal direction of the pack cross beam1200. Here, the longitudinal direction of the pack cross beam1200may be the direction in which the pack cross beam1200extends, which may be the direction in which the battery cell units100are stacked. InFIG.12, the longitudinal direction of the pack cross beam1200is a direction that is parallel to the Y axis. The mesh part1230may be formed from a metal material.

The pack cross beam1200provided with the mesh part1230can once again filter flames or particles passing through the gas passage1210. Additionally, it exhibits the effect of decreasing temperature while the gas passes through the mesh part1230.

On the other hand, referring toFIGS.1,6and11again, a thermal resin layer1300formed by applying thermal resin may be located on the bottom part1100F of the pack tray1100, and the battery cell assembly100A may be placed on the thermal resin layer1300. The thermal resin may include a thermally conductive adhesive material, and specifically, it may include at least one of a silicone material, a urethane material, or an acrylic material. The thermal resin may be in a liquid state during application, but may be cured after application, thereby functioning to fix the battery cell assembly100A. In addition, the thermal resin has excellent heat conduction properties and can quickly discharge heat generated in the battery cell110to the outside through the lower side of the battery pack1000.

As mentioned above, the cell cover200according to the present embodiment may include a side surface part210and an upper surface part220, and the lower side may be open based on the battery cell110located inside the cell cover200. In the case of the battery cell assembly100A including the battery cell unit100having such a structure, the battery cells110may directly face the bottom part1100F of the pack tray1100. Additionally, the battery cells110included in the battery cell assembly100A may directly contact the thermal resin layer1300provided on the bottom part1100F of the pack tray1100. Because the battery cells110are in direct contact with the thermal resin layer1300of the battery pack1000, the cooling performance of the battery pack1000can be further improved. The heat generated from each battery cell110is directly transferred to the bottom part1100F of the pack tray1100and is immediately released, thereby improving cooling performance. In this case, a structure such as a frame is not interposed between the battery cell110and the bottom part1100F of the pack tray1100, and there is only a thermal resin layer1300for heat transfer. Therefore, because the heat transfer path is simplified and the air gap between each layer can be reduced, the cooling efficiency and performance can be increased.

A heat sink1400may be located between the thermal resin layer1300and the bottom part1100F of the pack tray1100. A cooling channel1400C, which is a space in which a coolant flows, may be provided inside the heat sink1400. Heat generated from each battery cell110may be discharged to the outside through the thermal resin layer1300, the heat sink1400, and the bottom part1100F of the pack tray1100.

Next, the busbar module300of the battery cell unit100according to an embodiment of the present disclosure will be described in detail.

FIG.13is an exploded perspective view which enlarges and shows a battery cell and a busbar module included in the battery cell unit ofFIGS.5and6.FIG.14is a perspective view showing a busbar included in the busbar module ofFIGS.5and6.

Referring toFIGS.5,6,8,13and14, the battery cell unit100according to this embodiment may include at least one busbar module300that covers at least a part of the battery cell110where the electrode lead111is disposed. An opening part200P may be formed in the cell cover200according to this embodiment. In the cell cover200, opening parts200P may be formed on both sides of the direction in which the electrode lead111protrudes from the battery cell110. The busbar module300can be mounted in such an opening part200P.

The busbar module300may include a busbar310connected to the electrode lead111. The busbar310according to this embodiment is a member for electrical connection between the battery cells110, and may include a metal material such as copper or aluminum. More specifically, the busbar310may include a lead coupling part311coupled to the electrode lead111of the battery cell110and a terminal part312extending from the lead coupling part311.

When the busbar310is erected with respect to the ground, the lead coupling part311may extend vertically, and may be coupled to the electrode lead111of the battery cell110by a method such as welding. The terminal part312is a portion exposed to the outside of the cell cover200, which is a portion for guiding electrical connection of the battery cell unit100. This terminal part312may be formed with a hole312H provided in order to couple the terminal part312with an external busbar.

On the other hand, the busbar310according to this embodiment may further include a bent part313located between the lead coupling part311and the terminal part312. Such a bent part313may be a portion of the lead coupling part311that extends obliquely at a predetermined angle. When the lead coupling part311of the busbar310is coupled with the electrode lead111, the bent part313may be arranged so as to face the inner direction of the cell cover200rather than the electrode lead111. As shown inFIG.3, the upper parts of the sealing parts114sat both end parts114aand144bof the cell body113may be cut. In order to correspond to the shape of both end parts114aand144bof the cell body113, the busbar310may be provided with a bent part313that extends obliquely at a predetermined angle.

As shown inFIG.8, the cell cover200according to the present embodiment may be formed with an incision shape200N that exposes a part of the busbar310. The cell cover200includes a cover part230that protrudes from an end part of the cell cover200due to the incision shape200N.

At the upper end of the opening part200P of the cell cover200, a part of the side surface part210and a part of the upper surface part220may be incised to provide an incision shape200N. In the side surface part210, unlike the portion indented according to the incision shape200N, the portion that is not incised corresponds to the cover part230having a relatively protruding shape. That is, the incision shape200N and the cover part230may be provided in the opening part200P.

A part of the busbar310may be exposed toward the upper part of the cell cover200through the incision shape200N. More specifically, the terminal part312may be exposed toward the upper part of the cell cover200through the incision shape200N. Additionally, the upper side230U of the cover part230and the terminal part312may be spaced apart by the incision shape200N.

The incision shape200N may be changed depending on the position and size of the busbar310in the busbar module300according to the present embodiment. The incision shape200N can prevent contact between the cell cover200and the busbar310, thereby ensuring electrical insulation properties of the busbar module300. The incision shape200N can be set to a range where the electrical insulation of the bus bar module300can be secured. For example, when the overall position of the busbar310or the position of the terminal part312on the busbar310is adjusted to the lower side, the incision shape200N may be further incised in the downward direction. Particularly, the cell cover200may include a metal material to support and protect the at least one battery cell110arranged at its inside. At this time, since the cell cover200according to this embodiment is provided with an incision shape200N, the busbar, especially the terminal part312, contacts the cell cover200, thereby preventing occurrence of short circuits and ensuring the electrical insulation of the busbar module300.

On the other hand, the cover part230of the cell cover200may cover the side surface of the busbar module300. More specifically, the cell cover part230may cover the side surface of the busbar frame320of the busbar module300. Accordingly, the cover part230can protect the busbar module300from external shocks, vibrations, and the like, and the busbar module300can be stably mounted on the opening part200P of the cell cover200.

Further, the weight of the cell cover200can be reduced by the incision shape200N provided in the cell cover200. Thereby, it is possible to further improve the energy density of the battery cell unit100and the battery cell assembly100A including the same and also reduce the weight thereof to reduce the manufacturing costs.

FIG.15is a perspective view showing a busbar frame included in the busbar module ofFIGS.5and6.

Referring toFIGS.13to15together, the busbar module300according to this embodiment may further include a busbar frame320on which the busbar310is mounted and which includes an electrically insulating material.

The busbar frame320including an electrically insulating material may cover at least a part of the busbar310. Accordingly, the busbar frame320can prevent the busbar310contacting a part other than the electrode lead111and causing a short circuit.

The busbar frame320may include a perimeter part321that surrounds the circumference of the terminal part312and is mounted in the incision shape200N of the cell cover200. The perimeter part321may be formed with an upper hole321H, and the busbar310may be inserted into the internal space of the busbar frame320through the upper hole321H. The busbar310can be fixed inside the busbar frame320by various methods. For example, a method in which the protrusion part320PR provided in the inner space of the busbar frame320is inserted into the hole311H formed in the busbar310can be applied.

On the other hand, the busbar frame320may be formed with a slit320S. After the electrode lead111of the battery cell110passes through the slit320S, it may be bent and coupled to the lead coupling part311of the busbar310. The method of coupling the electrode lead111and the lead coupling part311is not especially limited, but as an example, welding junction can be applied. The busbar frame320may be formed with a busbar opening part320P, and welding work between the electrode lead111and the lead coupling part311can be performed through this busbar opening part320P. If the coupling between the electrode lead111and the lead coupling part311is completed, the busbar cover330and the insulating sheet340are assembled to the busbar frame320while covering the busbar opening part320P.

FIG.16is a partial view which enlarges and shows a portion where the busbar module is mounted in the battery cell unit ofFIG.5.

Referring toFIGS.13to16together, according to this embodiment, the perimeter part321surrounding the terminal part312of the busbar310may be located between the terminal part312and the cover part230. The upper side230U of the cover part230and the terminal part312may be spaced apart by the incision shape200N, and also the perimeter part321made of an electrically insulating material is interposed between the terminal part312and the cover part230, thereby further ensuring the electrical insulation of the busbar module300. While the perimeter part321of the busbar frame320is assembled to the incision shape200N of the cell cover200, structural stability and electrical insulation of the busbar module300can be improved.

Next, the structure of the battery cell assembly100A according to an embodiment of the present disclosure will be described.

Referring toFIGS.2to6together, the battery cell assembly100A of this embodiment may include a plurality of battery cell units100, a support plate120that supports one side of the battery cell unit100located at the outermost part of the plurality of battery cell units100, an end cover130that covers the front surface and the rear surface of the plurality of battery cell units100, and a fixing unit140that couples a plurality of battery cell units100to each other. Moreover, the battery cell assembly100A of this embodiment may further include a handle unit150.

As mentioned above, in the present embodiment, a plurality of battery cells110are not housed in a separate module case and mounted on the pack tray1100of the battery pack1000, but can be mounted directly on the pack tray1100in a state of being partially covered by a cell cover200having a simplified structure. Through such a structure of the battery cell unit100, the weight and volume of the entire battery pack1000can be reduced and the energy density of the battery pack1000can be improved. In addition, damage of the battery cells110occurring during the process of directly mounting multiple battery cells110in the case and using them can be prevented, and swelling control of the battery cell and design of the gas venting path can be easily performed.

On the other hand, prior to the description, the battery cell unit100may have a hexahedral shape having horizontal (length), vertical (width), and thickness, wherein the longitudinal direction may be the X-axis, the widthwise direction may be the Z-axis, and the thickness direction may be the Y-axis. The plurality of battery cell units100may be arranged successively along the thickness direction (Y-axis direction), and the thickness direction (Y-axis direction) may be referred to as a stacking direction of the battery cell unit100.

Here, the two surfaces facing each other in the longitudinal direction (X-axis direction) of the battery cell unit100may be referred to as a front surface and a rear surface, the two surfaces facing each other in the thickness direction (Y-axis direction) of the battery cell unit100may be referred to as side surfaces, and the two surfaces facing each other in the widthwise direction (Z-axis direction) of the battery cell unit100may be referred to as an upper surface and a lower surface.

The battery cell units100may be formed in plural numbers, and the plurality of battery cell units100may be arranged side by side in one direction. The battery cell units100may be stacked in one direction and housed in the pack tray1100. The battery cell units100may be arranged successively such that the side surfaces thereof and the side surfaces of adjacent battery cell units100are parallel to each other.

The battery cell unit100may be arranged in upright along the Z-axis direction so that its side surface is perpendicular to the pack tray1100. The battery cell unit100may be arranged such that its lower surface corresponds to the bottom part1100F of the pack tray1100.

The support plate120can be for maintaining the overall shape of the stacked battery cell units100. The support plate120can be for supporting the stacked battery cell unit100. In the battery pack1000, the battery cell unit100may be arranged such that one surface thereof is perpendicular to the bottom part1100F of the battery pack1000, and the support plate120may support one surface of the battery cell unit100so that the one surface thereof can maintain an upright state. The support plate120can prevent the plurality of battery cell units100from being spaced apart from each other, thereby fixing relative positions between the battery cell units100.

The support plate120may be a plate-shaped member and may supplement the stiffness of the battery cell assembly100A instead of the module frame.

The support plate120may be arranged on one surface of the outermost battery cell unit100among the stacked battery cell units100. The support plate120may be arranged on the side surface of the outermost battery cell unit100among the stacked battery cell units100.

Here, the support plates120provided in the battery cell assembly100A of this embodiment may be formed in two. The support plate120may comprise a first support plate120aand a second support plate120b. A pair of support plates120may be provided at both ends in the stacking direction of the stacked battery cell units100. The first support plate120acontacts the outermost battery cell unit100on one side of the stacked battery cell units100, and the second support plate120bmay contact the outermost battery cell unit100on the other side of the stacked battery cell units100.

The support plate120may be made from various materials, and may be provided by various manufacturing methods. As an example, the support plate120may be made from a metal material, and an example of the metal material may be aluminum. As another example, the support plate120may be made from a combination of aluminum and polymer synthetic resin through insert molding. However, the material and manufacturing method of the support plate120should not be limited by the contents described above, and it is possible to include various materials not mentioned or to make using other manufacturing methods.

The support plate120may include a support part122that supports the battery cell unit100, a cover coupling part124for coupling with the end cover130and a handle coupling part126for coupling with the handle unit150.

The support part122corresponds to the majority of the area of the support plate120, and may have a plate-like shape so as to support the battery cell unit100. The support part122may have a shape similar to the side surface shape of the battery cell unit100. The plate-shaped support part122may include both side edges in the longitudinal direction (X-axis direction) and in the width direction (Z-axis direction).

On the other hand, the support plate120and the plurality of battery cell units100are coupled by the fixing unit140, thereby being able to restrict relative positional movement. For this purpose, the support part122may be formed with a plate fastening hole123into which the fixing unit140is inserted. As will be described later, the plate fastening hole123may be formed at a position corresponding to the cell unit fastening hole115of the cell cover200included in the battery cell unit100. The plate fastening hole123may be located close to an end part in the longitudinal direction (X-axis direction) of the support plate120. This can be for preventing the battery cell110from being damaged by the fixing unit140penetrating through the support plate120and the cell cover200included in the battery cell unit100.

The number of the plate fastening hole123formed in the support plate120may be one. However, in order to stably couple the plurality of battery cell units100and the support plate120, the fixing unit140is preferably formed in plural numbers, so that the support plate120can be formed with a plurality of plate fastening holes123. As a specific example, the fixing unit140provided in the battery cell assembly100A may be formed in two, and the plate fastening holes123may be respectively formed at portions close to both ends in the longitudinal direction (X-axis direction) of the support plate120. When the plate fastening hole123is formed in plural numbers, the cell unit fastening holes115in each cell cover200may also be formed in plural numbers. At this time, the plurality of plate fastening holes123and the plurality of cell unit fastening holes115formed in each cell cover200may correspond to each other.

The cover coupling part124may provide a coupling surface between the support plate120and the end cover130. The cover coupling part124may have a shape extending from one edge of the support part122.

The cover coupling part124may be formed at one edge corresponding to the end cover130among the edges of the support part122. The end cover130can be arranged close to the end part in the longitudinal direction (X-axis direction) of the support plate120, and the cover coupling part124can be formed at an edge in the longitudinal direction (X-axis direction) of the support part122to provide a coupling surface with the end cover130. The cover coupling part124may have a shape extending toward the end cover130from an edge in the longitudinal direction (X-axis direction) of the support part122. The cover coupling part124may have a shape extending in parallel to one surface of the support part122. At this time, the end cover130may be arranged such that an end part in the longitudinal direction (Y-axis direction) thereof corresponds to an end part in the longitudinal direction (X-axis direction) of the support plate120.

The number of the cover coupling part124formed in one support plate120may be two. The cover coupling parts124may be located at each of two edges of the support parts122facing each other. As a more specific example, the end covers130may be formed in two, and the two end covers130may be arranged so as to correspond to end parts in the longitudinal direction (X-axis direction) of one support plate120. The cover coupling part124is formed at each of both edges in the longitudinal direction (X-axis direction) of the support part122, and the two cover coupling parts124may respectively correspond to the two end covers130. The cover coupling part124located at one end part in the longitudinal direction (X-axis direction) of the support plate120may correspond to one end cover130, and the cover coupling part124located at the other end part may correspond to the other end cover130. In this manner, the cover coupling part124may be formed in plural numbers on the support part122, and each cover coupling part124may be coupled to a cover extension part134formed on each end cover130.

On the other hand, the support plates120provided in the battery cell assembly100A may be formed in two, wherein one end part and the other end part in the longitudinal direction (X-axis direction) of the pair of support plates120may respectively correspond to one end part and the other end part in the longitudinal direction (Y-axis direction) of the pair of end covers130. Thereby, one end part in the longitudinal direction (Y-axis direction) of the end cover130may correspond to the cover coupling part124formed on the first support plate120a, and the other end part may correspond to the cover coupling part124formed on the second support plate120b.

The cover coupling part124may be formed with a second plate fastening hole125for coupling with the end cover130. The number of the second plate fastening hole125may be one, or may also be two or more. As an example, the number of the second plate fastening hole125may be one. In such a case, the coupling stability of the end cover130can be supplemented in accordance with the shape of the end cover130or the shape of other members. Further, when the number of the second plate fastening hole125is one, the manufacturing costs can be reduced and the manufacturing process can be simplified. Further, as another example, the second plate fastening hole125may be formed in two. In such a case, the reliability of coupling of the end cover130can be improved.

The handle coupling part126may provide a coupling surface between the support plate120and the handle unit150. The handle coupling part126can be coupled to at least one handle unit150.

Here, the handle unit150can stably seat the battery cell assembly100A inside the pack tray1100, and may include a handle that can be gripped by a user. One end part of the handle unit150may be detachably coupled to the support plate120, and the handle unit can be removed from the support plate120after the mounting of the battery cell assembly100A is completed.

The handle coupling part126may be formed in a shape extending from one edge of the support part122. The handle coupling part126may be located at one end part in the widthwise direction (Z-axis direction) of the support part122. More specifically, it may be located on the upper side based on the state in which the battery cell assembly100A is mounted. This may facilitate removal of the handle unit150after the mounting of the battery cell assembly100A is completed.

The end cover130can be protecting the front surface or the rear surface of the plurality of battery cell units100. The end cover130can cover the front surface or the rear surface of the plurality of battery cell units100. The end cover130may be located at end parts in the longitudinal direction of the stacked battery cell units100. The end covers130may be formed two, and the two end covers130may be respectively provided at both end parts in the longitudinal direction of the stacked battery cell units100.

The end cover130may integrally cover the terminal portions of the battery cells included in the plurality of battery cell units100. The end cover130may comprise body parts132corresponding to electrode lead111of the battery cells110included in the plurality of battery cell units100, and a cover extension part134that extends vertically from one edge of the body part132and couples to the support plate120.

The body part132can cover a front surface or a rear surface of the plurality of battery cell units100. The body part132may be located at an end part in the longitudinal direction of the plurality of battery cell units100. The body part132may cover the end parts in the longitudinal direction of the plurality of battery cell units100. The body part132may cover terminal portions of the battery cells included in the plurality of battery cell units100. Here, the body part132may also be referred to as a ‘terminal cover part’.

The body part132may have a shape nearly resembling a plate. The plate-shaped body part132may include both side edges in the longitudinal direction (Y-axis direction) and both side edges in the widthwise direction (Z-axis direction).

The body part132may be formed with a cover venting hole133. The cover venting hole133may be formed in plural numbers, and the plurality of the cover venting holes133may correspond to each battery cell unit100. However, each cover venting hole133does not necessarily have to correspond to one battery cell unit100, and a plurality of cover venting holes133can correspond to one battery cell unit100, or a plurality of battery cell units100can correspond to one cover venting hole133. The end cover130can protect the battery cell unit100from an external environment by the cover venting hole133and also discharge gas or the like generated from the battery cell110to the outside. Thereby, cascading thermal runaway phenomena of the battery cell assembly100A can be prevented.

The cover extension part134can provide a coupling surface for coupling between the end cover130and the support plate120.

The cover extension part134may be formed at one edge corresponding to the support plate120among the edges of the body part132. The support plate120may be arranged close to the end part in the longitudinal direction (Y-axis direction) of the end cover130, and the cover extension part134may be formed at an edge in the longitudinal direction (Y-axis direction) of the body part132to provide a coupling surface with the support plate120. The cover extension part134may have a shape extending from one edge of the body part132toward the support plate120. The cover extension part134may have a shape extending from one edge of the body part132toward the support plate120in a direction perpendicular to one surface of the body part132. At this time, the end cover130may be located at the end part in the longitudinal direction (X-axis direction) of the support plate120. The end cover130may be arranged such that the end part in the longitudinal direction (Y-axis direction) corresponds to the end part in the longitudinal direction (X-axis direction) of the support plate120.

The cover extension part134may correspond to an end part in the longitudinal direction (X-axis direction) of the support plate120. The cover extension part134may overlap with an end part in the longitudinal direction (X-axis direction) of the support plate120. The cover extension part134may be located outside the end part in the longitudinal direction (X-axis direction) of the support plate120. The cover extension part134may be coupled with an end part in the longitudinal direction (X-axis direction) of the support plate120.

The number of the cover extension parts134formed on one end cover130may be two. The two cover extension parts134may include a first cover extension part134aand a second cover extension part134bthat are respectively formed on two edges of the body part132facing each other. The first cover extension part134aand the second cover extension part134bmay be formed at both edges in the longitudinal direction (Y-axis direction) of the body part132.

More specifically, the first support plate120aand the second support plate120bmay be located so as to correspond to both end parts in the longitudinal direction (Y-axis direction) of the end cover130. The first cover extension part134alocated at one end part in the longitudinal direction (Y-axis direction) of the end cover130may correspond to the first support plate120a, and the second cover extension part134blocated at the other end part may correspond to the second support plate120b. The first cover extension part134aand the second cover extension part134bmay have a shape extending perpendicularly to one surface of the body part132toward the first support plate120aand the second support plate120b. The first cover extension part134aand the second cover extension part134bmay respectively correspond to end parts of the first support plate120aand the second support plate120b. The first cover extension part134aand the second cover extension part134bcan be respectively overlapped and coupled with end parts of the first support plate120aand the second support plate120b. The first cover extension part134amay be located outside the first support plate120a, and the second cover extension part134bmay be located outside the second support plate120b. Here, the outer side of a specific member may be described on the basis of the center of the battery cell assembly100A. In addition, as will be described later, the first cover extension part134aand the second cover extension part134bcan respectively correspond to the cover coupling parts124formed on the first support plate120aand the second support plate120b.

The cover extension part134may correspond to the cover coupling part124of the support plate120. The cover extension part134may overlap with the cover coupling part124. The cover extension part134may be coupled to the cover coupling part124of the support plate120. More specifically, the cover extension part134may be located outside the cover coupling part124, and an inner side surface of the cover extension part134may contact an outer side surface of the cover coupling part124.

The outer side surface of the cover coupling part124may have a shape recessed toward the inner side surface so that the cover extension part134and the cover coupling part124can easily overlap each other, and the cover extension part134can be seated on the recessed outer side surface. Further, each corner of the cover extension part134may have a round shape. Thereby, when the end cover130is mounted on the combination of the battery cell unit100and the support plate120, interference between the support plate120and the end cover130can be minimized.

On the other hand, conventionally, in order to protect the battery cells from an external environment, a module frame that covers the upper, lower, left and right surfaces of the stacked battery cells and end plates that cover the front and rear surfaces thereof are provided. Also, at the outside of the battery cells, the module frame and the end plate are mainly coupled by welding. However, in the present embodiment, by omitting the module frame, the end cover130and the support plate120are coupled, and the end cover130and the support plate120are coupled by a fastening member, so that a welding process may not be added. Thereby, the manufacturing process can be completed more easily and quickly. Further, a cover extension part134is formed on the end cover130, and the support plate120is formed with a cover coupling part124corresponding thereto, so that the coupling between the end cover130and the support plate120can be stably and easily performed.

The cover extension part134may be formed with a cover fastening hole135for coupling with the support plate120. The cover fastening hole135may correspond to the second plate fastening hole125formed in the cover coupling part124. In the manufacturing process of the battery cell assembly100A of this embodiment, the end cover130may be arranged so as to be located on the same axis of the cover fastening hole135and the second plate fastening hole125, and a second fixing unit may be inserted into the cover fastening hole135and the second plate fastening hole125, thereby being able to couple the end cover130and the support plate120. Here, the second fixing unit may be a fastening member such as a bolt or a rivet.

The number of the cover fastening hole135may be one, but may also be two or more. For this information, refer to the description of the second plate fastening hole125. When the cover fastening hole135is formed in plural numbers, the second plate fastening hole125may also be formed in plural numbers, and the plurality of cover fastening holes135and the second plate fastening holes125may correspond to each other.

On the other hand, the battery cell units100of the present embodiment may be coupled by the fixing unit140, and the relative movement of the battery cell units100may be restricted by the fixing unit140. The fixing unit140may couple the support plate120and the battery cell unit100. The fixing unit140may pass through the plate fastening hole123formed in the first support plate120a, then pass through the cell unit fastening hole115formed in the cell cover200included in the plurality of battery cell units100, and may pass through the plate fastening hole123formed in the second support plate120b. Thereby, relative movement between the support plate120and the cell unit100is restricted, and the battery cell assembly100A can be made into blocks.

In this manner, the plurality of battery cell units100can be made in blocks by the fixing unit140and the relative positions of the battery cell units100can be fixed, thereby making the handling of the battery cell assembly100A easier. That is, the mounting of the battery cells110may be facilitated by the fixing unit140, and a structure required for mounting the battery cells110is simplified, thereby capable of achieving effects such as weight reduction and manufacturing cost reduction.

The fixing unit140can be provided in a shape of a long bolt. The fixing unit140may be provided as a long bolt having a sufficient length to penetrate through all of the plurality of battery cell units100included in the battery cell assembly100A.

On the other hand, the figures show that the fixing unit140penetrates through the lower side portion of the battery cell assembly100A, but this is not necessarily the case. It is also possible to provide at other positions as long as the battery cell110and the electrode lead111are not damaged. For example, the fixing unit140may be provided so as to penetrate through an upper side portion of the battery cell assembly100A, whereby the positions of the plate fastening hole123and the cell unit fastening hole115through which the fixing unit140passes can be adjusted.

The terms representing directions such as the front side, the rear side, the left side, the right side, the upper side, and the lower side have been used in the present embodiment, but the terms used are provided simply for convenience of description and may become different according to the position of an object, the position of an observer, or the like.

The one or more battery cell assemblies according to embodiments of the present disclosure described above can be mounted together with various control and protection systems such as a BMS (battery management system), a BDU (battery disconnect unit), and a cooling system to form a battery pack.

The battery pack can be applied to various devices. For example, it can be applied to vehicle means such as an electric bike, an electric vehicle, and a hybrid electric vehicle, or an ESS (Energy Storage System) and may be applied to various devices capable of using a secondary battery, without being limited thereto.

Although the invention has been described in detail with reference to preferred embodiments of the present disclosure, the scope of the present disclosure is not limited thereto, and various modifications and improvements can be made by those skilled in the art using the basic concepts of the present disclosure, which are defined in the appended claims, which also falls within the scope of the present disclosure.