CN117941151A - Battery pack and device comprising same - Google Patents

Abstract

The battery pack according to an embodiment of the present invention includes: a plurality of battery cell units arranged side by side in one direction; and a battery pack case accommodating a plurality of battery cell units, wherein the battery cell units include at least one battery cell and a cell cover covering a portion of the battery cell, and wherein the cell cover has an upper inclined shape.

Description

Battery pack and device comprising same

Technical Field

Cross Reference to Related Applications

The present application claims priority from korean patent application No. 10-2022-0089758, filed in the korean intellectual property office at 20-7-2022, and korean patent application No. 10-2023-0090048, filed in the korean patent application No. 11-7-2023, each of which is incorporated herein by reference in its entirety.

The present invention relates to a battery pack and a device including the same, and more particularly, to a battery pack having high energy density and improved safety against thermal runaway, and a device including the same.

Background

With the rapid increase in demand for portable electronic products such as notebook computers, video cameras and mobile phones and the active progress in development of electric vehicles, energy storage batteries, robots, satellites, etc., a great deal of research is being conducted on high-performance secondary batteries capable of repeated charge and discharge.

Currently, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, lithium secondary batteries, and the like are commercially available secondary batteries. Among them, lithium secondary batteries are an important point of attention because lithium secondary batteries have little memory effect and can be freely charged and discharged when compared with nickel-based secondary batteries. Advantageously, lithium secondary batteries also exhibit very low self-discharge rates and high energy densities.

Lithium secondary batteries generally use lithium oxide and carbonaceous materials as a cathode active material and an anode active material, respectively. The lithium secondary battery includes: an electrode assembly in which an anode plate and a cathode plate coated with a cathode active material and an anode active material, respectively, are disposed, and a separator interposed between the anode plate and the cathode plate; and an exterior material sealing and accommodating the electrode assembly and the electrolyte.

Meanwhile, lithium secondary batteries may be classified into can-type secondary batteries in which an electrode assembly is included in a metal can and pouch-type batteries in which an electrode assembly is included in a pouch of an aluminum laminate, according to the shape of a battery case. In addition, can-type secondary batteries can be classified into cylindrical batteries and prismatic batteries according to the shape of a metal can.

Here, the soft-pack type secondary battery is formed by stacking and winding a cathode, an anode, and a separator to form an electrode assembly, accommodating the electrode assembly in a case sheet, and sealing the edges of the sheet by heat sealing or the like. In addition, the electrode tabs drawn from the respective electrodes may be combined with the electrode leads, and a portion of the electrode leads may protrude outside the edge of the sheet.

In this way, the soft pack type secondary battery may have flexibility to be configured in various forms. Further, the soft pack type secondary battery has an advantage in that it is possible to realize secondary batteries having the same capacity with a smaller volume and weight.

Such a lithium secondary battery may be used in the shape of a battery module or a battery pack including a plurality of battery cells to provide high voltage and high current. The battery module is provided in a shape including a plurality of battery cells inside the module case, and the battery pack may be provided in a shape including at least one or more such battery modules.

In such a battery pack structure, one typically important issue is safety. In particular, when a thermal accident occurs in one of a plurality of battery cells included in a battery pack, it is necessary to suppress the spread of such an accident to other battery cells. If the heat propagation between the battery cells is not properly restrained, this may result in a thermal accident among several battery cells included in the battery pack, which may cause the ignition or explosion of the battery pack. In addition, fires or explosions occurring in the battery pack may cause significant injury to surrounding human lives or loss of surrounding property. Therefore, in the case of such a battery pack, a structure capable of appropriately controlling the above-described thermal accident is required.

Disclosure of Invention

Technical problem

Accordingly, the present invention has been designed to solve the above-mentioned problems, and it is an object of the present invention to provide a battery pack, a device, etc., which can have improved safety by minimizing a cascade ignition phenomenon even when a thermal runaway phenomenon occurs.

Technical proposal

According to an embodiment of the present invention, there is provided a battery pack including: a plurality of battery cell units arranged side by side in one direction; and a battery pack case accommodating a plurality of battery cell units, wherein the battery cell units include at least one battery cell and a cell cover covering a portion of the battery cell, and wherein the cell cover has an upper inclined shape.

The battery cell cover may be formed such that the length value of the edge in the width direction is greater than the length value of the center portion in the width direction.

The battery cell cover may have a shape inclined upward toward an end in the length direction.

The battery cells are vertically disposed such that one edge corresponds to the bottom surface of the battery pack case, and the battery cell cover covers the upper side edge of the vertically disposed battery cells, and the lower side edge of the battery cells may be opened.

The battery cell cover includes: a second surface and a third surface disposed parallel to one surface of the battery cell; and a first surface extending between the second surface and the third surface, and the cross section of the battery cell cover may be n-shaped.

The second surface includes a second center portion and a second edge portion, and a length value of the second center portion in the width direction may be smaller than a length value of the second edge portion in the width direction.

The upper side edge of the second surface may have a shape inclined upward toward an end of the second surface in the length direction.

The cross section of the first surface in the width direction may have a shape inclined upward toward the end in the length direction.

The cell cover may include a fourth surface extending between the first surface, the second surface, and the third surface.

The fourth surface may partially cover the open end of the battery cell cover in the length direction.

The bottom surface of the battery pack case may be formed with a vent hole communicating with the outside.

The vent hole may be located at a position corresponding to an end of the battery cell unit in the length direction.

A plurality of vent holes are provided, and the plurality of vent holes may be disposed side by side along a straight line.

According to another embodiment of the present invention, there is provided an apparatus including the above-described battery pack.

Advantageous effects

According to an aspect of the present invention, a large number of soft pack type battery cells can be stably accommodated inside a case without using, for example, a laminated frame (e.g., a plastic case) or a configuration of a separate module case.

Further, according to an aspect of the present invention, the soft pack type battery cell having the soft material case can be easily made into a rigid shape, so that a configuration in which the battery cell is directly laminated inside the case can be more easily achieved.

According to still another aspect of the present invention, the safety against the gas generated in the battery cell can be improved. In particular, according to one embodiment of the present invention, a directional exhaust structure of gas or flame may be implemented to control the direction of gas discharge.

According to still another aspect of the present invention, the energy density, the assembling ability, the cooling performance, etc., of the battery pack can be improved.

In addition, the present invention may have additional other effects, which will be described in various embodiments, or a description of effects that can be easily inferred by those skilled in the art will be omitted.

Drawings

Fig. 1 is a perspective view of a battery cell according to an embodiment of the present invention.

Fig. 2 is a perspective view of a battery cell according to an embodiment of the present invention.

Fig. 3 is a diagram illustrating a portion of the battery cell unit according to fig. 1.

Fig. 4 is a view illustrating a front surface or a rear surface of the battery cell unit according to fig. 1.

Fig. 5 is a view illustrating a side surface of the battery cell unit according to fig. 1.

Fig. 6 is a diagram illustrating a gas exhaust path when a thermal accident occurs in the battery cells included in the battery cell unit according to the present embodiment.

Fig. 7 is a diagram showing a battery pack case of the battery pack according to the present embodiment.

Fig. 8 is an enlarged view of portion A-A of fig. 7.

Fig. 9 and 10 are diagrams schematically illustrating directional exhaust of a battery pack according to an embodiment of the present invention.

Fig. 11 is a view showing a state in which a case is provided for a plurality of battery cell units according to an embodiment of the present invention; and

Fig. 12 is an enlarged view of the lower surface of the housing according to fig. 11.

Detailed Description

Hereinafter, preferred embodiments of the present application will be described in detail with reference to the accompanying drawings. The terms or words used in the present specification and claims should not be construed as limited to typical meanings or dictionary definitions, but should be construed to have meanings and concepts related to the technical scope of the present application based on the rule that the inventor can properly define terms according to the best method he or she knows to describe the present application. Therefore, the embodiments described in the specification and the configurations shown in the drawings are merely the most exemplary embodiments of the present application and do not fully cover the spirit of the present application. It is therefore to be understood that there may be various equivalents and modifications capable of replacing those embodiments when submitting the application.

In the drawings, the dimensions of the individual components or specific parts of the constituent components are exaggerated, omitted, or schematically shown for convenience of description and clarity. Therefore, the size of each component cannot fully reflect the actual size. Further, in order to avoid unnecessarily obscuring the subject matter of the present invention, detailed descriptions related to well-known functions or configurations may be omitted.

In addition, it will be understood that when an element such as a layer, film, region or plate is referred to as being formed on or disposed "over" another element, it should be understood to include not only the case where the element such as a layer, film, region or plate is directly on the other element but also the case where intervening elements are present. In contrast, when an element such as a layer, film, region or plate is referred to as being "directly formed on" or disposed on "another element, it can be drawn to the absence of other intervening elements. Further, the word "upper" or "above" means disposed above or below the reference portion, and does not necessarily mean disposed at the upper end of the reference portion toward the opposite direction of gravity. Meanwhile, similarly to the case where it is described as being formed or disposed "on" or "over" another component, the case where it is described as being formed or disposed "under" or "under" another element will also be understood with reference to the above.

Furthermore, throughout the description, when a portion is referred to as "comprising" or "including" a particular component, this means that the portion may also include other components, which are not excluded unless stated otherwise.

Further, in the entire description, when referred to as a "plane", this means that the target portion is observed from the upper side at this time, and when referred to as a "section", this means that the target portion is observed from the side of the vertically cut section at this time.

The battery cell according to the embodiment of the present invention will be described below.

Fig. 1 is a perspective view of a battery cell according to an embodiment of the present invention. Fig. 2 is a perspective view of a battery cell according to an embodiment of the present invention. Fig. 3 is a diagram illustrating a portion of the battery cell unit according to fig. 1. Fig. 4 is a view illustrating a front surface or a rear surface of the battery cell unit according to fig. 1. Fig. 5 is a view illustrating a side surface of the battery cell unit according to fig. 1. Fig. 6 is a diagram illustrating a gas exhaust path when a thermal accident occurs in the battery cells included in the battery cell unit according to the present embodiment.

Referring to fig. 1 to 6, a battery cell unit 100 according to an embodiment of the present invention may include a battery cell 110 received in a state in which an electrode assembly is impregnated with an electrolyte, and a battery cell cover 200 covering a portion of the battery cell 110. The battery cell 100 may be the smallest unit body that protects the battery cell 110.

Before the description, the battery cell unit 100 may have a hexahedral shape having a horizontal (length), a vertical (width), and a thickness, wherein the length direction may be an X-axis, the width direction may be a Z-axis, and the thickness direction may be a Y-axis. Further, when the battery cell units 100 are vertically arranged as shown in the drawing, the width direction (Z-axis direction) may also be referred to as the height direction. The plurality of battery cell units 100 may be continuously arranged in 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 units 100.

Here, two surfaces facing each other in the length direction (X-axis direction) of the battery cell unit 100 are referred to as a front surface and a rear surface, two surfaces facing each other in the thickness direction (Y-axis direction) of the battery cell unit 100 are referred to as side surfaces, and two surfaces facing each other in the width direction (Z-axis direction) of the battery cell unit 100 are referred to as an upper surface and a lower surface.

Referring to fig. 2, the battery cell 110 of the present embodiment may be a pouch type battery cell capable of maximizing the number of stacked battery cells per unit area. The battery cell provided in the pouch type may be manufactured by accommodating an electrode assembly including a cathode, an anode, and a separator in a battery cell case of a laminate sheet, and then heat-sealing the sealed portion of the battery cell case. It is apparent, however, that the battery cells do not necessarily have to be provided in a pouch type, and may be provided in a square, cylindrical, or other various shapes at a level of a storage capacity required to achieve a device installed in the future.

The battery cell 110 may include two electrode leads 111 and 112. Each of the electrode leads 111 and 112 may be disposed to protrude from one edge of the battery cell case 101 toward one direction. The electrode leads 111 and 112 may be disposed to protrude at one side of the edge of the battery cell 110 on which the sealing part 130 is formed. One end portions of the electrode leads 111 and 112 may be positioned inside the battery cell 110 to be electrically connected with a cathode or an anode of the electrode assembly, and the other end portions of the electrode leads 111 and 112 may be drawn out of the battery cell 110 to be electrically connected with another member, such as a bus bar.

The battery cell 110 may include a case part 120 accommodating the electrode assembly and a sealing part 130 formed at an edge of the battery cell 110 to seal the electrode assembly. In the case of a pouch-type battery cell, the battery cell may be manufactured by accommodating an electrode assembly in the battery cell case 101 and then sealing the edge of the battery cell case 101 located outside the electrode assembly. When the battery cell 110 is formed by accommodating the electrode assembly in the inner space formed by folding the battery cell case 101 and then sealing edges of the three surfaces of the opening, the sealing part 130 may be formed at three edges among the four edges of the battery cell case 101, wherein the remaining one edge may be referred to as a non-sealing part 132. However, unlike the above, it is also possible to heat-seal all four edges of the battery case to manufacture the battery cell 110, and in this case, the sealing parts 130 may be formed at all four edges of the battery cell 110.

As shown in fig. 2, the battery cell 110 may have a hexahedral shape having a horizontal (length), a vertical (width), and a thickness, wherein the length direction may be an X-axis, the width direction may be a Z-axis, and the thickness direction may be a Y-axis. Based on the hexahedral shape, the battery cell 110 may be described as including two surfaces (surfaces on the XZ plane) corresponding to the case part 120 and four surfaces located at the edges of the case part 120. However, in the case of the pouch-type battery cell 110, since the thickness value of the sealing part 130 formed by heat sealing is small, the battery cell 110 will be described as having two surfaces corresponding to the case part 120 and four edges located at the outside of the case part 120 for convenience of explanation. At this time, when one surface of the battery cell 110 is disposed to stand in the Z-axis direction such that it is perpendicular to the ground, the edge in the +z-axis may be described as an upper side edge, and the edge in the-Z-axis may be described as a lower side edge.

The battery cell 110 of this embodiment may be covered by a battery cell cover 200 and provided in the form of a battery cell unit 100. The battery cells 110 are provided in the form of the battery cell unit 100, whereby a module case protecting the battery cells 110 from the external environment can be omitted, and the battery cells 110 can be directly mounted and accommodated inside the battery pack case 300 without requiring a module case. In the case of the pouch-type battery cell, since the battery cell case is made of a soft material, it is easily affected by external impact and has low hardness. Therefore, it may be difficult for only the battery cells themselves to be accommodated inside the battery pack case 300 without being accommodated in the module case. However, in the present embodiment, since the battery cell cover 200 supplements the rigidity of the battery cells 110, the battery cells 110 may be directly received in the inside of the battery pack case 300 and may be maintained in a laminated state. Further, since conventional fastening members such as a module case, a laminated frame, and bolts may be omitted by the battery cell cover 200, the manufacturing process may be simplified, the internal structure may be simplified, the weight and volume of the battery pack may be reduced, and the energy density may be improved.

The rigidity of the battery cells 110 is supplemented by the battery cell cover 200 in this way so that the battery cells 110 can be more conveniently handled in the battery pack assembly process. More specifically, in the process of accommodating the battery cells 110 in the battery pack case 300, the battery cell cover 200 coupled with the battery cells 110 may be clamped, thereby preventing the battery cells 110 from being damaged, and the assembly process may be more easily performed. Further, the expansion control of the battery cell 110 and the design of the gas discharge path can be easily performed.

The battery cell cover 200 may be used to cover at least a portion of the outer surface of the battery cell 110. The battery cell cover 200 may cover a portion of the battery cell 110 and expose another portion, thereby improving cooling efficiency and guiding gas generated from the battery cell 110 in a predetermined direction.

The cell cover 200 supplements the rigidity of the battery cells 110 so that the battery cells 110 can be maintained in an upright state. The battery cell cover 200 may cover at least a portion of the battery cells 110 to support the battery cells 110, and may be provided to stand in one direction to stably maintain the laminated state of the battery cells 110. More specifically, since the second surface 220 and the third surface 230 of the battery cell cover 200 support one surface of the battery cell 110, the erected state of the battery cell 110 is maintained. Further, the lower side edge of the battery cell cover 200 may be seated on the bottom surface 312 of the battery pack case 300 such that the battery cell cover 200 may stand alone and the standing state of the battery cells 110 inside the battery cell cover 200 may be maintained.

The battery cell cover 200 may cover both surfaces of the battery cell 110 and one edge between the both surfaces. Alternatively, it may be described as covering both surfaces of the hexahedral battery cells 110 facing each other and one surface sharing one edge with both surfaces.

The battery cell cover 200 may include second and third surfaces 220 and 230 parallel to and spaced apart from each other and a first surface 210 extending between the second and third surfaces 220 and 230. One edge of the first surface 210 may be connected with one edge of the second surface 220, and the other edge of the first surface 210 may be connected with one edge of the third surface 230. Alternatively, the second surface 220 may be described as extending in a first direction from one edge of the first surface 210, and the third surface 230 may be described as extending in the first direction from another edge of the first surface 210. At this time, the first direction is a direction substantially perpendicular to the first surface 210, and the first direction is denoted as a-Z axis direction in the drawing. In this way, the cross section of the battery cell cover 200 may be n-shaped, wherein the cross section may refer to a cross section in the length direction (X-axis direction) of the battery cell cover 200.

The battery cell cover 200 may cover one surface of the battery cell 110. The second surface 220 and the third surface 230 of the battery cell cover 200 may cover both sides of the battery cell 110. The second surface 220 and the third surface 230 of the battery cell cover 200 may be disposed parallel to one surface of the battery cell 110. More specifically, as shown in fig. 4, the second surface 220 may cover one surface on the right side (-Y axis) of the battery cell 110 from the right side. The third surface 230 may cover one surface on the left side (+y axis) of the battery cell 110 from the left side.

The second surface 220 and the third surface 230 of the cell cover 200 separate the cells 110 from the neighboring cells 110, thereby preventing gas generated in one cell 110 from moving to the neighboring cells 110. In addition, the battery cell cover 200 is in contact with one surface of the battery cell 110 or is disposed close to one surface of the battery cell 110 such that heat generated in the battery cell 110 can be transferred to the battery cell cover 200, thereby promoting heat dissipation of the battery cell. Further, when the lower side edge of the battery cell cover 200 is disposed in contact with the battery pack case 300 (see fig. 7) accommodating the battery cell unit 100, a heat transfer path may be formed to move to the battery cells 110, the battery cell cover 200, and the battery pack case 300, thereby improving the overall cooling efficiency of the battery pack.

The battery cell cover 200 may cover one edge of the battery cell 110. The first surface 210 of the battery cell cover 200 may cover one edge of the battery cell 110. The battery cell cover 200 may cover the upper side edges of the battery cells 110 arranged vertically such that one edge corresponds to the bottom surface 312 (see fig. 7) of the battery pack case 300. The first surface 210 of the cell cover 200 may correspond to the upper side edge of the cell 110 in the erected state.

The battery cell cover 200 may not cover the lower side edge corresponding to the bottom surface 312 of the battery pack case 300 in the vertically arranged battery cells 110, and the lower side edge of the battery cells 110 may be exposed toward the bottom surface 312. Thereby, the battery cell 110 is in contact with the bottom surface 312 of the battery pack case 300 or is disposed close to the bottom surface 312 of the battery pack case 300, so that heat generated in the battery cell 110 can be rapidly discharged to the bottom surface 312 of the battery pack case 300. At this time, when the cooling member is located on the bottom surface 312 of the battery pack case 300, the heat dissipation effect may be further improved.

The battery cell cover 200 may include a fourth surface 240 extending between the first surface 210, the second surface 220, and the third surface 230. The fourth surface 240 may be described as extending in the first direction from an edge of the first surface 210 in the length direction (X-axis direction). The fourth surfaces 240 may be provided in two, and the two fourth surfaces 240 may be formed at both ends of the battery cell cover 200 in the length direction (X-axis direction). The fourth surface 240 may be perpendicular to the second surface 220 and the third surface 230. Depending on the shape of the first surface 210, the fourth surface 240 may form an acute angle with the first surface 210.

On the other hand, the end of the battery cell cover 200 in the length direction (X-axis direction) may be in an open state, and the electrode leads 111 and 112 of the battery cell 110 may be disposed at the end of the battery cell cover 200 in the length direction (X-axis direction). Here, the fourth surface 240 may be formed to partially cover the open end. The fourth surface 240 is formed on the battery cell cover 200 such that the gas generated inside the battery cell 110 can be prevented from moving along the length direction (X-axis direction) of the battery cell cover 200. The fourth surface 240 may prevent the gas in the battery cell 110 from moving toward the electrode leads 111 and 112. The fourth surface 240 may also be referred to as a "closure.

In general, in the event of a fire in the battery cell 110, when gas, spark, etc. move in the direction of the electrode leads 111 and 112, the gas, spark, etc. may further damage the electrode leads 111 and 112 of the adjacent battery cell 110, the bus bars of the battery pack, etc., which results in a problem in that the thermal runaway phenomenon is exacerbated. However, in the battery cell unit 100 of the present embodiment, one surface of the battery cell cover 200, where the electrode leads 111 and 112 are located, is partially covered by the fourth surface 240, so that movement of gas and sparks toward the electrode leads 111 and 112 can be minimized.

Referring to fig. 5, the battery cell cover 200 of the present embodiment may have a shape with an upper portion inclined. As the battery cell cover 200 is closer to the end in the length direction (X-axis direction), the battery cell cover 200 may have a shape in which the value of the length in the width direction is larger. As the battery cell cover 200 is closer to the end in the length direction (X-axis direction), the height value may be larger. The battery cell cover 200 may have an "M" shape as a whole based on the front surface (XZ plane).

The cell cover 200 may include a central portion 202 and a rim portion 204. The battery cell cover 200 may have a shape inclined upward from the center 202 toward the edge 204. The center portion 202 may be a portion including a center CT of the battery cell cover 200 in the length direction (X-axis direction), and the edge portion 204 may be a portion including an edge of the battery cell cover 200 in the length direction (X-axis direction).

Meanwhile, as will be described later, the central portion 202 of the battery cell cover 200 includes a first central portion 212 of the first surface 210, a second central portion 222 of the second surface 220, and a third central portion (not shown) of the third surface 230. The edge portion 204 of the cell cover 200 may include a first edge portion 214 of the first surface 210, a second edge portion 224 of the second surface 220, and a third edge portion (not shown) of the third surface 230. Since the second surface 220 and the third surface 230 are closer to the end in the length direction (X-axis direction), the second surface 220 and the third surface 230 can be provided in a shape with a larger width. Here, the length direction of the second surface 220 and the third surface 230 may correspond to the X-axis direction, and the width direction may correspond to the Z-axis direction.

More specifically, the second surface 220 may include a second center portion 222 and a second edge portion 224. The second center portion 222 may be a portion including a center CT of the second surface 220 in the length direction (X-axis direction), and the second edge portion 224 may be a portion including an edge of the second surface 220 in the length direction (X-axis direction).

On the second surface 220, a width LA of the second central portion 222 may be smaller than a width LB of the second edge portion 224. The length LA in the width direction of the second center portion 222 may be a minimum value of the length in the width direction of the second surface 220, and the length LB in the width direction of the second edge portion 224 may be a maximum value of the length in the width direction of the second surface 220. Since the second surface 220 is closer to the second central portion 222, the second surface 220 may have a relatively small length value in the width direction, and since the second surface 220 is closer to the second edge portion 224, the second surface 220 may have a relatively large length value in the width direction.

The upper side edge of the second surface 220 may be formed in a shape inclined corresponding to a change in the length value in the width direction. The second surface 220 may have an overall "M" shape. More specifically, the upper side edge of the second surface 220 may have a shape inclined upward toward an end of the second surface 220 in the length direction (X-axis direction). The upper side edge of the second surface 220 may have a shape inclined upward from the second center portion 222 toward the second edge portion 224. Here, the upper side edge may be an edge located on the +z axis of the second surface 220.

The above description of the second surface 220 may also apply to the third surface 230.

On the other hand, the upper side edges of the second surface 220 and the third surface 230 have an inclined shape, so that the first surface 210 connected with the second surface 220 and the third surface 230 may also have an inclined shape. More specifically, the first surface 210 may include a first central portion 212 and a first edge portion 214. The first center portion 212 may be a portion including a center CT of the first surface 210 in the length direction (X-axis direction), and the first edge portion 214 may be a portion including an edge of the first surface 210 in the length direction (X-axis direction).

The first center portion 212 may correspond to the second center portion 222. The position value (i.e., the length value in the width direction) of the first center portion 212 with respect to the ground may correspond to the length value in the width direction of the second center portion 222. The first edge portion 214 may correspond to the second edge portion 224. The height value of the first edge portion 214 with respect to the ground may correspond to the length value of the second edge portion 224 in the width direction.

The first surface 210 may be formed to be inclined at an angle to the ground. At this time, the ground may be described as the bottom surface 312 of the battery pack case 300 or the bottom surface 412 of the module case 400. On the first surface 210, the first central portion 212 may be located relatively lower than the first edge portion 214. On the first surface 210, the first edge portion 214 may be located relatively higher than the first center portion 212. The first surface 210 may have a shape inclined upward toward an end in the length direction (X-axis direction). The first surface 210 may have a shape inclined upward from the center toward the edge portion. The cross section of the first surface 210 in the width direction (Y-axis direction) may have a shape inclined upward from the center toward the edge portion. The cross section (XZ plane) of the first surface 210 in the width direction (Y axis direction) may have a "V" shape.

Referring to fig. 6, the battery cell cover 200 of the present embodiment may have a shape with an upper portion inclined, and when thermal runaway occurs, a gas discharge direction is limited, thereby preventing cascading thermal runaway. Here, the arrows in fig. 6 may illustrate the discharge direction of the gas.

Since the battery cell cover 200 has an inclined shape, when compared to a conventional battery cell cover structure in which an upper portion is configured to be flat, the volume inside the battery cell cover 200 may be increased, and exhaust gas or flame flow may be guided along the battery cell cover 200 configured to be inclined upward during thermal runaway of the battery cell 110.

More specifically, the center portion 202 of the cell cover 200 may have a relatively small volume, and the edge portion 204 may have a relatively large volume. When the degassing is generated inside the battery cell cover 200 due to the thermal runaway phenomenon, the degassing may move to the edge part 204 having a relatively large volume to eliminate the elevated internal pressure of the battery cell cover 200. Meanwhile, the fourth surface 240 may be located at the edge portion 204, thereby preventing the exhaust gas from further moving along the length direction (X-axis direction) of the battery cell cover 200. The gas may change its moving direction by colliding with the fourth surface 240 so as to move toward the lower side (-Z-axis direction) of the battery cell cover 200. As will be described later, a vent hole may be provided on the lower surface of the battery pack case 300 where the battery cell unit 100 is mounted, and such a vent hole may be provided to correspond to the gas discharge direction caused by the battery cell cover 200, so that exhaust gas or flame may be prevented from being randomly discharged from the battery cell cover.

The battery cell cover 200 may be made of a material having a high melting point so that it does not melt even during thermal runaway of the inside of the battery pack. Further, the battery cell cover 200 may be made of a material having a mechanical strength greater than a predetermined range to stably support the battery cells 110, so that the battery cells 110 may be protected from external impact or the like. Examples of the material for the battery cell cover 200 include steel, stainless steel (SUS), and the like.

The battery cell cover 200 may be coupled to cover the battery cells 110 at the upper sides of the battery cells 110. Here, a heat conductive resin or the like having an adhesive property may be provided between the battery cell cover 200 and the battery cell 110, but this is not necessarily the case, and any other material may not be interposed between the battery cell cover 200 and the battery cell 110. This may minimize the volumes of the battery cell cover 200 and the battery cells 110 to maximize the number of battery cells 110 accommodated inside the battery pack case 300, thereby maximizing the energy density of the battery pack.

In the present embodiment, the battery cell cover 200 has been described as individually covering one battery cell 110, but this is not necessarily the case, and the battery cell cover 200 may be designed to include two or more battery cells 110 according to the intention of a designer.

In the present embodiment, the cell cover 200 has been described as being provided for all the battery cells 110, but this is not necessarily the case, and the cell cover 200 may be provided only on a portion of the plurality of battery cells 110.

The battery cell cover 200 of the present embodiment has been described as having an n-shape, but the battery cell cover 200 may be configured in other shapes as long as the battery cell cover 200 can achieve the purpose of preventing gas or the like from being transferred to the electrode leads 111 and 112 and other electronic components. For example, the cell cover may be formed asA "U" shape, an "O" shape, an "L" shape, etc.

Meanwhile, although not specifically shown, the battery cell cover 200 of the present embodiment may be provided with a clamping member. The clamping members may be clamped between different ends of the battery cell cover 200 to prevent the different ends of the battery cell cover 200 from being spaced apart or deformed. For example, the clamping member may be disposed at the lower end of the battery cell cover 200 where the lower side edge of the battery cell 110 is located, and prevent the second surface 220 from being spaced apart from the third surface 230, thereby being able to maintain the accommodated state of the battery cell 110. As a specific example, the clamping member may be an adhesive tape. As another specific example, the holding member may be a metal material having elasticity.

On the other hand, although not specifically shown, the bus bar frame may be coupled with an end of the battery cell cover 200 in the length direction (X-axis direction). The end of the battery cell cover 200 in the length direction (X-axis direction) may be in an open state, and the open end may be covered by a bus bar frame. The bus bar frame may electrically connect the battery cells 110 covered by the battery cell cover 200 with an external conductive member or an adjacent battery cell 110. The bus bar frame may be configured to support the electrode leads 111 and 112 of at least one battery cell 110 and electrically connect the electrode leads 111 and 112 of the battery cell 110 with the electrode leads 111 and 112 of an adjacent battery cell 110. The bus bar frame may include bus bars made of a conductive material such as copper and a bus bar case made of a plastic material such as PC.

Next, a battery pack including the above-described battery cell units will be described.

Fig. 7 is a diagram showing a battery pack case of the battery pack according to the present embodiment. Fig. 8 is an enlarged view of portion A-A of fig. 7. Fig. 9 and 10 are diagrams schematically illustrating directional exhaust of a battery pack according to an embodiment of the present invention. Here, the arrows in fig. 10 may exemplify the exhaust direction of the gas.

The battery cell unit 100 of the present embodiment may be accommodated inside the battery pack case 300 and provided in the form of a battery pack. The battery cell 100 may be received inside the battery pack case 300 so as to be protected from the external environment. The battery cell units 100 may be provided in plurality, and the plurality of battery cell units 100 may be stacked in one direction and accommodated in the battery pack case 300. The battery cell units 100 may be continuously arranged such that one surface thereof and one surface of an adjacent battery cell unit 100 are parallel to each other. The battery cell units 100 may be continuously arranged such that the sides thereof and the sides of the neighboring battery cell units 100 are parallel to each other. One surface of the battery cell 100 may be perpendicular to the bottom surface 312 of the battery pack case 300. The battery cell units 100 may be arranged such that the lower surface corresponds to the bottom surface 312 of the battery pack case 300.

Meanwhile, the plurality of battery cells 110 may be arranged along the thickness direction (Y-axis direction) or the left-right direction of the battery cells 110. Further, the plurality of battery cells 110 may be arranged along the length direction (X-axis direction) or the front-rear direction of the battery cells 110. In this way, the plurality of battery cells 110 are stacked in the thickness direction (Y-axis direction) to form a battery cell assembly. Such battery cell assemblies may be arranged in two rows and two columns along the thickness direction (Y-axis direction) and the length direction (X-axis direction) and are accommodated in the battery pack case 300. However, since this is only one example, the battery cell assemblies may be continuously arranged in the thickness direction (Y-axis direction) or may be continuously arranged in the length direction (X-axis direction).

As shown in fig. 7, the battery pack case 300 may include a lower case 310 and an upper case 320. The lower case 310 may include a bottom surface 312 and a lower side surface 314 extending perpendicularly from one corner of the bottom surface 312, and the plurality of battery cells 110 may be accommodated in the inner space formed thereby. In addition, the upper case 320 may include an upper surface 322 and an upper side 324 extending perpendicularly from one corner of the upper surface 322. The lower side 314 may overlap at least a portion of the upper side 324. Here, the upper side 324 may be formed with an upper coupling portion 326 vertically extending from one surface of the upper side 324, and the lower side 314 may be formed with a lower coupling portion 316 vertically extending from one surface of the lower side 314. The lower case 310 and the upper case 320 may be coupled by coupling the upper coupling portion 326 with the lower coupling portion 316.

However, the structure of the above-described battery pack case 300 is only one example, and the battery pack case 300 of this embodiment may be provided in a structure different from the above-described structure. For example, the battery pack case 300 may include a bottom surface, a side surface extending perpendicularly from one corner of the bottom surface, and an upper surface parallel to the bottom surface and coupled with respective edges of the lower side surface. Here, the bottom surface, the lower side surface, and the upper surface may be integrally formed, and this configuration may be referred to as a single frame structure. Alternatively, the bottom surface, underside, and upper surface may be joined by a welding process. In this way, the battery pack case 300 of the present embodiment is not limited to the one shown, and various modifications or changes may be made as long as the shape thereof is capable of accommodating the battery cell units 100 therein and protecting the battery cell units 100.

Meanwhile, an adhesive may be disposed between the battery cells 110 and the battery pack case 300 such that the battery cells 110 received in the battery cell cover 200 may be stably disposed in the battery pack case 300. More specifically, an adhesive is interposed between one edge of the battery cell 110 and the bottom surface 312 of the battery pack case 300. At this time, one edge of the battery cell 110 provided with the adhesive may be the non-sealing part 132. Examples of the adhesive that can be used include a heat conductive resin, TIM, and the like, and a known material may be applied as long as it is a material having heat conductivity or adhesiveness. In addition, such an adhesive may be disposed between the battery cell cover 200 and the battery pack case 300 or between the battery cell 110 and the battery cell cover 200 to provide rigidity to the structure of the battery pack.

Referring to fig. 8, the bottom surface 312 of the battery pack case 300 of the present embodiment may be formed with a vent hole 330 for discharging gas generated in the battery cells 110 to the outside of the battery pack case 300. The vent 330 may be used to communicate the inside and the outside of the battery pack case 300.

The battery cell cover 200 covering the outer surface of the battery cell 110 may be in a state in which the lower surface is open, and the battery cell cover 200 may not cover the lower side edge of the battery cell 110. Thus, the battery cells 110 may be exposed to the outside of the battery cell cover 200 to face the bottom surface 312 of the battery pack case 300.

As shown in fig. 6 and 10, the movement of the gas generated in the battery cell 110 is restricted by the cell cover 200 and is concentrated at the lower side edge of the battery cell 110. The exhaust gas collected inside the lower cell cover 200 may be discharged to the outside through the exhaust hole 330 formed in the bottom surface 312 of the battery pack case 300.

The vent holes 330 may correspond to the plurality of battery cell units 100, respectively. The vent holes 330 may be provided in plurality, and at least one vent hole 330 may correspond to each battery cell 100. Alternatively, one vent 330 may correspond to a plurality of battery cell units 100.

The plurality of vent holes 330 may be disposed side by side along the stacking direction of the battery cell units 100. When the battery cell units 100 are continuously arranged in the thickness direction (Y-axis direction) as described above, the plurality of vent holes 330 may be continuously arranged in the thickness direction (Y-axis direction) of the battery cell units 100.

The vent 330 may correspond to an end of the battery cell unit 100 in the length direction (X-axis direction). The vent holes 330 may be provided in two rows or two columns to correspond to the ends of the battery cell units 100 in the length direction (X-axis direction), respectively. The vent holes 330 may be continuously formed on the bottom surface 312 of the inner space where the plurality of battery cell units 100 are accommodated along two straight lines parallel to each other.

Referring to fig. 9 and 10, effects of the present invention due to the battery cell cover 200 can be explained. More specifically, movement of the gas generated in the battery cell 110 by the thermal incident is restricted by the battery cell cover 200, and concentrated on the bottom surface 312 of the battery pack case 300, and can be discharged through the vent hole 330 formed in the bottom surface 312. More specifically, movement of the gas generated in the thickness direction (Y-axis direction) in the battery cell 110 is restricted by the second surface 220 and the third surface 230 of the battery cell cover 200. Further, movement of the gas in the length direction (X-axis direction) is restricted by the fourth surface 240 of the battery cell cover 200. In addition, since the upward (+z-axis) movement is also restricted by the first surface 210 of the battery cell cover 200, gas may be collected at the lower side (-Z-axis), and thus, may be discharged through the exhaust hole 330 provided in the battery pack case 300. Further, since the battery cell cover 200 has a shape with an upper portion inclined, the internal gas may be collected at the end of the battery cell cover 200 in the length direction (X-axis direction). The exhaust hole 330 is provided to correspond to an end of the battery cell cover 200 in the length direction (X-axis direction) such that the internal gas can be rapidly exhausted through the exhaust hole 330.

Meanwhile, in the above description, a non-module structure in which a battery cell assembly including a plurality of battery cells 110 is not sealed by a module case is mainly described. Here, the non-module structure may be referred to as a cell to pack (cell to pack) structure in which the battery cell structure is directly combined with the battery pack structure without a module case.

However, unlike the above, the battery cell unit 100 of the present embodiment may be mounted in a battery pack and housed inside a separate case.

Fig. 11 is a view showing a state in which a case is provided for a plurality of battery cell units according to an embodiment of the present invention. Fig. 12 is an enlarged view of the lower surface of the housing according to fig. 11.

Referring to fig. 11 and 12, the battery cell unit 100 of the present embodiment may be accommodated in a module case 400 and mounted in a battery pack in a modularized state.

The module housing 400 may be provided in various forms. In one example, the structure of the module case 400 may be a single frame structure. Here, the single frame may be in the form of a metal plate in which the upper surface 422, the bottom surface 412, and the two sides 414 are integrated. The single frame may be made by extrusion. In another example, the structure of the module case 400 may be a structure in which a U-shaped frame is combined with an upper plate. In the case of the structure in which the U-shaped frame is combined with the upper plate, the structure of the module case 400 may be formed by combining the upper surface 422 with the upper sides of the U-shaped frames 412 and 414, which are metal plates whose lower surfaces are combined with both sides or integrally formed, in which the respective members may be manufactured by press molding. Further, the structure of the module case 400 may be provided as an L-shaped frame structure, in addition to a single frame or a U-shaped frame, and may be provided as various structures not described in the above examples.

The battery cells 110 located inside the module case 400 may be in the form of battery cell units 100 protected by the cell covers 200. At this time, the battery cell cover 200 included in the battery cell unit 100 may be in a state in which the lower surface is open, and may not cover the lower side edge of the battery cell 110. Thus, the battery cells 110 may be exposed to the outside of the battery cell cover 200 to face the bottom surface 412 of the module case 400. The exhaust hole 430 may be formed in the bottom surface 412 to exhaust the gas generated in the battery cell 110 to the outside of the module case 400.

As shown in fig. 10, due to the inclined shape of the battery cell unit 100, the internal gas of the battery cell unit 100 may be collected at the end in the length direction (X-axis direction) and may move downward. The vent holes 430 may be provided to correspond to the ends of the battery cell units 100 in the length direction (X-axis direction), so that the vent holes 430 may easily correspond to the downward moving gas and the gas may be rapidly discharged.

The vent holes 430 of the module case 400 are similar in purpose and use to the vent holes 330 of the battery case 300. Accordingly, for more details regarding the vent holes 430 of the module housing 400, reference is made to the description of the "vent holes 330" of fig. 7-10 above.

On the other hand, fig. 11 shows that the electrode leads 111 and 112 of the battery cell 110 are exposed to the outside of the battery cell cover 200, and are received in the module case 400 of the battery cell 110 in this state. However, this is only a simplified drawing, and when the actual battery cells 110 are accommodated in the module case 400, the battery cells 110 accommodated in the respective battery cell units 100 may be electrically connected with neighboring battery cells 110 and/or bus bars through bus bar frames or the like.

On the other hand, the battery pack and the battery module are separately illustrated in the above description, but both the battery pack and the battery module include the battery cell unit 100 including the battery cell 110, and may refer to the smallest unit that is sold or used. Therefore, in the present specification, the battery pack and the battery module may be interchangeably referred to.

In addition, the above-described battery pack case 300 and module case 400 protect the battery cell units 100 from the external environment and are used in the same manner, and may be collectively referred to as cases.

Meanwhile, a battery module including the battery pack and the battery pack may be applied to various devices. Such a device may be not only a vehicle device such as an electric bicycle, an electric vehicle or a hybrid vehicle, but also an ESS (energy storage system). Further, the present invention is not limited thereto, and may be applied to various devices capable of using a battery module including a battery pack and a battery pack, which also fall within the scope of the present invention.

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

[ Description of reference numerals ]

100: Battery cell unit

110: Battery cell

200: Battery cell cover

300: Battery pack case

312: Bottom surface

330: Exhaust hole

400: Module shell

412: Bottom surface

430: Exhaust hole

Claims (15)

1. A battery pack, comprising:

A plurality of battery cell units arranged side by side in one direction; and

A battery pack case accommodating the plurality of battery cells,

Wherein the battery cell unit includes at least one battery cell and a battery cell cover covering a portion of the battery cell, and

Wherein the battery cell cover has a shape with an upper portion inclined.

2. The battery pack according to claim 1, wherein the cell covers are formed such that the length value of the edges in the width direction is greater than the length value of the center portion in the width direction.

3. The battery pack according to claim 1, wherein the cell cover has a shape inclined upward toward an end in a length direction.

4. The battery pack of claim 1, wherein,

The battery cells are vertically disposed such that one edge corresponds to the bottom surface of the battery pack case, and

The battery cell cover covers an upper side edge of the battery cell vertically disposed, and a lower side edge of the battery cell is opened.

5. The battery pack of claim 1, wherein,

The battery cell cover includes: a second surface and a third surface disposed parallel to one surface of the battery cell; and a first surface extending between the second surface and the third surface, an

The section of the battery cell cover is n-shaped.

6. The battery pack of claim 5, wherein,

The second surface includes a second center portion and a second edge portion, an

The second center portion has a length value in the width direction smaller than a length value of the second edge portion in the width direction.

7. The battery pack according to claim 5, wherein an upper side edge of the second surface has a shape inclined upward toward an end of the second surface in a length direction.

8. The battery pack according to claim 5, wherein a cross section of the first surface in the width direction has a shape inclined upward toward an end in the length direction.

9. The battery pack of claim 5, wherein the cell cover includes a fourth surface extending between the first surface, the second surface, and the third surface.

10. The battery pack according to claim 9, wherein the fourth surface partially covers an opening end of the cell cover in a length direction.

11. The battery pack according to claim 1, wherein the bottom surface of the battery pack case is formed with a vent hole communicating with the outside.

12. The battery pack according to claim 11, wherein the vent hole is located at a position corresponding to an end of the battery cell unit in the length direction.

13. The battery pack according to claim 11, wherein a plurality of the vent holes are provided, and the plurality of vent holes are provided side by side along a straight line.

14. The battery pack of claim 1, wherein the plurality of battery cells are housed in the battery pack housing while being housed in separate housings.

15. An apparatus comprising the battery pack of claim 1.