Battery assembly

Abstract

The invention relates to a battery assembly, which is characterized by comprising a shell for accommodating a plurality of battery cells; the heat dissipation part is positioned between the plurality of battery cells and the accommodating bottom surface; and a pad part located between a plurality of battery packs in which adjacent cells among the plurality of cells are grouped into one group according to a predetermined number of cells, the absolute value of the difference between the surface hardness of the heat dissipation part and the surface hardness of the pad part being less than or equal to a predetermined allowable value.

Description

Technical Field

[0001] The present disclosure relates to a battery assembly, and more particularly to a battery assembly with improved stability and lifespan. Background Art

[0002] The conventional battery assembly includes an electrophoretic pad, which is located between the multiple cells contained in the battery assembly and applies appropriate pressure to the cells. This is to prevent lithium plating caused by the lifting of the electrode interface inside the cell.

[0003] In addition, the conventional battery assembly includes a thermal adhesive that supports and fixes the plurality of battery cells inside the housing and dissipates heat of the plurality of battery cells to the outside.

[0004] Generally speaking, the heat dissipation adhesive and the surface pressure pad may be formed of materials with different surface hardness. At this time, the pressure applied to the battery cell may be uneven, and the stress may be concentrated locally. This pressure deviation may cause damage to the battery cell. In addition, the gas that is inevitably generated inside the battery cell may not be discharged smoothly. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] According to one aspect of the present disclosure, a technical problem to be solved is to maintain uniform pressure inside a battery cell by eliminating surface pressure deviations of a plurality of battery cells and a heat dissipation portion.

[0007] According to another aspect of the present disclosure, a technical problem to be solved is to prevent local stress concentration on an outer packaging material or a shell of a battery cell.

[0008] According to another aspect of the present disclosure, a technical problem to be solved is to delay fire and / or explosion of a battery assembly by allowing exhaust gas generated inside a battery cell to be discharged through a predetermined exhaust path when discharged.

[0009] According to yet another aspect of the present disclosure, a technical problem to be solved is to improve the lifespan and stability of a battery assembly.

[0010] On the other hand, the battery assembly according to the present disclosure can be widely used in electric vehicles, battery charging stations, energy storage systems (ESS), and other green technology fields such as photovoltaic power generation and wind power generation using batteries. In addition, the battery assembly according to the present disclosure can be used for eco-friendly mobility tools including electric vehicles and hybrid vehicles that prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0011] (II) Technical solution

[0012] The battery assembly according to the present disclosure may include: a shell, accommodating a plurality of battery cells; an accommodating bottom surface, forming the bottom surface of the shell; a heat dissipation portion, located between the plurality of battery cells and the accommodating bottom surface; and a pad portion, located between a plurality of battery groups in which one or more of the plurality of battery cells are grouped according to a predetermined number of battery cells. Based on Shore A hardness, the absolute value of the difference between the surface hardness of the heat dissipation portion and the surface hardness of the pad portion may be less than or equal to 50.

[0013] In addition, the pad portion may be deformed according to expansion and contraction of a battery cell adjacent to the pad portion.

[0014] On the other hand, the heat dissipation portion may include a thermally conductive material.

[0015] In addition, the heat dissipation portion may include an adhesive material.

[0016] In addition, the heat dissipation portion may be applied to the receiving bottom surface in a viscous liquid state, and then solidified into a solid state after a predetermined period of time.

[0017] The multiple battery cells can be stacked along a predetermined stacking direction, and each of the multiple battery cells may include: a main body portion, accommodating an electrode assembly that stores or generates electrical energy; and a lead connector portion, which is electrically connected to the electrode assembly and protrudes to the outside of the main body portion in a direction perpendicular to the stacking direction, and the pad portion can contact the main body portion of a portion of the battery cells among the multiple battery cells that is closest to the pad portion.

[0018] The heat dissipation portion may be in contact with the accommodation bottom surface, a pad bottom surface of the pad portion facing the accommodation bottom surface, and a body bottom surface of the body portion facing the accommodation bottom surface.

[0019] The pad portion may be provided in plurality, and the plurality of pad portions may pressurize one surface of each of the main body portions with a pressure equal to or greater than a predetermined surface pressure value.

[0020] In addition, the main body may include: a main body one side facing the stacking direction; a main body second side facing the main body one side; and a main body bottom surface connected to the main body one side and the main body second side and facing the accommodating bottom surface. Through the pad portion and the heat dissipation portion, the absolute value of the pressure difference applied to the main body one side, the main body second side and the main body bottom surface may be less than or equal to a predetermined allowable pressure.

[0021] On the other hand, the pad portion may be formed by stacking different materials.

[0022] The cushion part may include an inner layer part having a sheet shape and formed of a polymer material; and an outer layer part respectively bonded to both surfaces of the inner layer part and formed of a flame retardant material.

[0023] On the other hand, the battery assembly may further include: a bus bar assembly located inside the housing and electrically connecting the plurality of battery cells to the outside.

[0024] Each of the multiple battery cells may include: a main body portion, which internally accommodates an electrode assembly that stores or generates electrical energy; and a lead joint portion, which protrudes from the inside of the main body portion to the outside to connect the electrode assembly and the bus bar, and the bus bar assembly may include: a bus bar, which is electrically connected to each of the lead joint portions; a bus bar frame, which is located between the bus bar and each of the main bodies to support the bus bar; a through hole, which is formed through the bus bar frame in a direction from the main body portion toward the bus bar, so that each of the lead joint portions is inserted into the through hole; and a contact portion, which is located between the inner side surface of the through hole and the lead joint portion, and is in contact with the through hole and the lead joint portion, and the absolute value of the difference between the surface hardness of the contact portion and the surface hardness of the bus bar frame may be less than or equal to a predetermined difference.

[0025] The contact portion may have a foamed form of a polymer material.

[0026] In a direction from the main body toward the bus bar, a length of an inner side surface of the through hole may be greater than or equal to a length of the contact portion.

[0027] On the other hand, a battery assembly according to the present disclosure may include: a plurality of battery cells arranged in one direction, each of the plurality of battery cells including: a main body portion storing or generating electrical energy internally; a lead connector protruding from the inside of the main body portion to the outside of the main body portion; a lead film located in an area of ​​the outer side surface of the lead connector that contacts the main body portion to insulate the lead connector from the main body portion; a bus bar extending in the one direction and electrically connected to each of the lead connectors; a bus bar frame located between the bus bar and each of the main bodies to support the bus bar; a plurality of through holes formed through the bus bar frame, each of the lead connectors being inserted into the through holes; and a plurality of contact portions located in the plurality of through holes and contacting each of the lead films, the absolute value of the difference between the surface hardness of each of the lead films and the surface hardness of each of the contact portions being less than or equal to 50, based on the Shore A hardness.

[0028] In addition, based on Shore A hardness, an absolute value of a difference between a surface hardness of each of the contact portions and a surface hardness of the busbar frame may be less than or equal to 50.

[0029] On the other hand, the battery assembly according to the present disclosure may include: a shell body, accommodating multiple battery cells; a accommodating bottom surface, forming the bottom surface of the shell body; a heat dissipation portion, located between the multiple battery cells and the accommodating bottom surface; and a pad portion, located between the multiple battery cells, and based on the Shore A hardness, the absolute value of the difference between the surface hardness of the heat dissipation portion and the surface hardness of the pad portion may be less than or equal to 50.

[0030] On the other hand, the battery assembly according to the present disclosure may include: a shell, forming a storage space for accommodating multiple battery cells; a storage bottom surface, forming the bottom surface of the storage space; a partition frame, dividing the storage space into multiple spaces; a heat dissipation part, located between the multiple battery cells and the storage bottom surface; and a pad part, located between the multiple battery cells, and based on the Shore A hardness, the absolute value of the difference between the surface hardness of the heat dissipation part and the surface hardness of the pad part may be less than or equal to 50.

[0031] (III) Beneficial effects

[0032] According to one embodiment of the present disclosure, the pressure inside the battery cells may be kept uniform by eliminating surface pressure deviations of the plurality of battery cells and the heat dissipation portion.

[0033] According to another embodiment of the present disclosure, local stress concentration on an outer packaging material or a case of a battery cell can be prevented.

[0034] According to yet another embodiment of the present disclosure, the exhaust gas generated inside the battery cell is discharged through a predetermined exhaust path during discharge, thereby delaying the fire and / or explosion of the battery assembly.

[0035] According to yet another embodiment of the present disclosure, the lifespan and stability of a battery assembly may be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is an exploded view of one example of a battery assembly according to the present disclosure.

[0037] Figure 2 is a diagram showing one example of a plurality of battery cells and a pad portion located inside a battery assembly.

[0038] Figure 3 is an example of enlarging a pad portion according to the present disclosure.

[0039] Figure 4 Various embodiments are shown according to changes in the surface hardness of the heat dissipation portion and the pad portion.

[0040] Figure 5 A cross section of the busbar frame, the busbars, the contact portions, and the lead tab portions viewed from the Z direction is shown.

[0041] Figure 6 Another example of a battery assembly according to the present disclosure is schematically illustrated.

[0042] Description of reference numerals:

[0043] 100: Battery cell stack

[0044] 110: Battery Cell

[0045] 115: Main body

[0046] 1153: Bottom of the main body

[0047] 118: Pad

[0048] 1183: bottom surface

[0049] 151: Busbar

[0050] 155: Busbar frame

[0051] 1559: Through hole

[0052] 200: Battery components

[0053] 210, 310: Shell

[0054] 291, 319: Accommodation space

[0055] 2191, 3191: Accommodate bottom surface

[0056] 295, 395: Heat dissipation DETAILED DESCRIPTION

[0057] The preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The configuration or control method of the device described below is only used to illustrate the embodiments of the present disclosure and is not intended to limit the scope of the present disclosure. The same reference numerals used throughout the specification represent the same components.

[0058] Specific terms used in this specification are for convenience of description only and are not intended to limit the illustrated embodiments.

[0059] On the other hand, the term battery assembly according to the present disclosure is a general term for battery modules, battery packs, and energy storage systems (ESS). The battery module refers to a battery assembly in which a plurality of battery cells are grouped into a group in a number of more than one and placed in a housing to protect them from external impacts, heat, vibration, etc.

[0060] And, the battery pack refers to a battery assembly that accommodates a predetermined number of the battery modules to achieve a final required voltage or power.

[0061] In addition, the battery assembly according to the present disclosure may refer to a battery pack having a cell to pack (CTP) structure, which omits a battery module and accommodates a predetermined number of cells to generate a required voltage or power.

[0062] Figure 1 is an exploded view of one example of a battery assembly 200 according to the present disclosure.

[0063] Reference Figure 1 The battery assembly 200 includes: a housing 210, accommodating a plurality of battery cells 110; a accommodating bottom surface 2191, forming the bottom surface of the housing 210; a heat dissipation portion 295, located between the plurality of battery cells 110 and the accommodating bottom surface 2191; and a pad portion 118, located in a plurality of battery groups BG1, BG2, BG3, BG4, BG5 (refer to Figure 2 )between.

[0064] Any one of the plurality of battery cells 110 may include a main body portion 115 including an electrode assembly (not shown) storing or generating electric energy, and a lead connector portion 111 electrically connected to the electrode assembly and protruding to the outside of the main body portion 115 .

[0065] That is, any one of the battery cells 110 refers to a secondary battery that can be used by charging and discharging electric energy. Specifically, the electrode assembly (not shown) may have a stacked form of a positive electrode (Cathode), a negative electrode (Anode) and a separator (Separator), and the interior of the main body 115 may include the electrode assembly and an electrolyte (Electrolyte) in contact with at least a portion of the electrode assembly.

[0066] The main body 115 may be an outer packaging material (or a bag) made of a flexible material, or may be a housing having a shape such as a cylinder or a prism.

[0067] The lead tab 111 may protrude from the inside of the body 115 to the outside to electrically connect the electrode assembly to the outside. The lead tab 111 is electrically connected to the electrode assembly inside the body 115 and to the bus bar assembly 150 outside the body 115.

[0068] Reference Figure 1 The plurality of battery cells 110 may be arranged in any direction. Considering the narrow space of the housing 210, the plurality of battery cells 110 may be arranged in a predetermined stacking direction (eg, Figure 1 The stacking direction may be one of any directions.

[0069] like Figure 1 As shown, the multiple battery cells 110 can be arranged along the stacking direction so that the main body surface 1151 facing the stacking direction and the main body surface 2 (not shown) located in the opposite direction of the main body surface 1151 on the surface of any one of the battery cells 110 overlap with the main body surface 1151 or the main body surface 2 of another adjacent battery cell 110.

[0070] Specifically, stacking the plurality of battery cells 110 along the stacking direction means that each of the main body one side 1151 is arranged side by side with each other and each of the main body two sides is arranged side by side with each other.

[0071] That is, each of the main bodies 115 of the plurality of battery cells 110 will be stacked along the stacking direction. In other words, each of the main bodies 115 may be arranged to overlap along the Y direction.

[0072] The battery assembly 200 may further include a bus bar assembly 150 for electrically connecting the plurality of battery cells 110 to the outside. The bus bar assembly 150 may include: a bus bar 151 (refer to Figure 5 ), electrically connected to the plurality of battery cells 110; and a busbar frame 155, supporting the busbar 151.

[0073] The plurality of battery cells 110 and the bus bar assembly 150 coupled to the plurality of battery cells 110 may be referred to as a cell stacking assembly.

[0074] The bus bar 151 may be formed of a metal material having conductivity, and the bus bar frame 155 may be formed of a polymer material for electrical insulation. The bus bar 151 may be formed of copper or aluminum, and the bus bar frame 155 may be formed of a polymer material such as engineering plastic. Therefore, the bus bar frame 155 may be injection molded, and the bus bar frame 155 may be referred to as an injection molded article.

[0075] The bus bar 151 may connect the plurality of battery cells 110 in series or in parallel in order to output electric energy at a predetermined voltage through the plurality of battery cells 110 .

[0076] The bus bar 151 and the bus bar frame 155 may extend in the stacking direction at a position where each of the lead tab parts 111 protrudes.

[0077] Reference Figure 1 The lead connector portion 111 protrudes to both sides of the main body portion 115 in a direction away from the main body portion 115 , so the bus bar 151 and the bus bar frame 155 can also be located on both sides of the plurality of battery cells 110 .

[0078] On the other hand, the plurality of battery cells 110 may repeatedly expand and contract during charging and / or discharging. Therefore, the battery assembly 200 may require a member that performs a buffering function for the deformation of the plurality of battery cells 110. To this end, the battery assembly 200 may further include a pad 118, which is located between battery groups BG1, BG2, BG3, BG4, and BG5 that group the battery cells 110 adjacent to each other in the plurality of battery cells 110 according to a predetermined number of battery cells, so as to pressurize the plurality of battery cells.

[0079] The pad 118 may be located between each of the battery cells 110. However, considering the limited space of the battery assembly, the pad 118 is preferably located between the battery groups BG1, BG2, BG3, BG4, and BG5.

[0080] In addition, the plurality of battery cells 110 may also generate heat during charging and discharging. Since the plurality of battery cells 110 need to operate under constant conditions, it is preferred to discharge the heat generated in the plurality of battery cells 110 to the outside as quickly as possible.

[0081] To this end, the battery assembly 200 may further include a heat dissipation portion 295 located between the plurality of battery cells 110 and the receiving bottom surface 2191. The heat dissipation portion 295 may be made of a thermally conductive material and an adhesive material.

[0082] The heat dissipation portion 295 including a thermally conductive material may improve the thermal conductivity of the battery assembly 200 by contacting the plurality of battery cells 110 and the receiving bottom surface 2191 .

[0083] In addition, the heat dissipation portion 295 including an adhesive material may also play a role in fixing the plurality of battery cells 110 inside the housing 210 .

[0084] On the other hand, the heat dissipation portion 295 may be a material that is coated on the receiving bottom surface 2191 in a liquid state and then cured into a solid state when manufacturing the battery assembly 200. On the other hand, the heat dissipation portion 295 may be a polymer material with viscosity in a liquid state.

[0085] In addition, the heat dissipation portion 295 may be formed of a material having both the thermal conductivity and the adhesive properties, rather than being formed by mixing the thermal conductive material and the adhesive material.

[0086] Reference Figure 1 , the housing 210 may form a housing space 291 for housing the battery stack 100. The housing 210 may include: the housing bottom surface 2191, which is the bottom surface of the housing space 291 and forms the bottom surface of the housing 210; and a first side surface 2193 and a second side surface 2195 facing each other among the side surfaces of the housing space 291. The first side surface 2193 and the second side surface 2195 may be respectively connected to the housing bottom surface 2191 to form a housing body 219. That is, when viewed from the Y direction, the housing body 219 may be set to a U-shape or a channel shape with an open top surface.

[0087] The housing 210 may further include a receiving cover 211 disposed to face the receiving bottom surface 2191 and coupled to the first side surface 2193 and the second side surface 2195 .

[0088] In addition, the shell 210 may further include end plates 230 and 250, and the end plates 230 and 250 are connected to the first side surface 2193, the second side surface 2195, the receiving bottom surface 2191 and the receiving cover 211 to respectively close the two ends of the opening of the receiving body 219.

[0089] That is, the end plates 230 , 250 , the receiving bottom surface 2191 , the first side surface 2193 , the second side surface 2195 and the receiving cover 211 together form the receiving space 291 .

[0090] Figure 2 1 is a diagram showing an example of a plurality of battery cells 110 and a pad 118 located inside a battery assembly 200 .

[0091] As described above, due to the contraction and expansion of the plurality of battery cells 110 during charging and discharging, the volume of each of the main body portions 115 may change. The battery assembly 200 may further include a cushion portion 118 that acts as a buffer to cope with the volume change of each of the main body portions 115. In addition, the cushion portion 118 may be configured to pressurize each of the main body portions 115 with a pressure greater than a predetermined surface pressure value. Therefore, the cushion portion 118 may be referred to as a cushion pad, a pressure pad, or a surface pressure pad.

[0092] The pad 118 may be located between the plurality of battery cells 110. Considering the size of the accommodation space 291, the pad 118 may preferably be located between the battery groups BG1, BG2, BG3, BG4, and BG5 that group the plurality of battery cells 110 according to a predetermined number of battery cells.

[0093] In the present specification, the battery groups BG1 , BG2 , BG3 , BG4 , and BG5 refer to a group in which at least one battery cell 110 adjacent to each other among the plurality of battery cells 110 is grouped according to a predetermined number of battery cells.

[0094] Therefore, the number of the battery groups BG1, BG2, BG3, BG4, and BG5 may be equal to or less than the number of the plurality of battery cells. However, since the battery groups BG1, BG2, BG3, BG4, and BG5 form a group of adjacent battery cells 110, the number of the battery groups is preferably less than the number of the plurality of battery cells.

[0095] Although Figure 2 Five battery groups BG1 , BG2 , BG3 , BG4 , and BG5 are shown as an example, but the number of the battery cells and the number of the battery groups are not limited thereto and may vary according to the design.

[0096] On the other hand, the battery assembly 200 may include a pad 118 located between the battery groups BG1, BG2, BG3, BG4, and BG5. In addition, the pad 118 may be located not only between the battery groups BG1, BG2, BG3, BG4, and BG5, but also between the plurality of battery cells 110 and the housing 210 along the stacking direction.

[0097] That is, if the battery cells 110 located at both ends along the stacking direction are respectively referred to as a first battery cell (not shown) and a second battery cell (not shown), the pad 118 can be located between the first battery cell and the first side 2193 and between the second battery cell and the second side 2195 .

[0098] If the stacking directions are different, the pad 118 may be located between the first battery cell and any one of the end plates 230 , or between the second battery cell and another end plate 250 .

[0099] Reference Figure 2 , the number of cells may vary depending on the position. Along the stacking direction, the number of cells in the battery pack closest to the first side 2193 and the second side 2195 may be different from the number of cells in the remaining battery packs. In addition, the number of battery packs located at both ends along the stacking direction among the multiple battery packs BG1, BG2, BG3, BG4, and BG5, that is, the number of the two battery packs BG1 and BG5 closest to the first side 2193 and the second side 2195 may be different from the number of the remaining battery packs BG2, BG3, and BG4.

[0100] The pad 118 may be located between each of the battery groups BG1 , BG2 , BG3 , BG4 , BG5 , may be located between the first side 2193 and a battery group closest to the first side 2193 , or may be located between the second side 2195 and another battery group closest to the second side 2195 .

[0101] The thickness of the pad 118 may also vary depending on the position. For example, the thickness of the pad 118 between the first side surface 2193 and a battery pack BG5 closest to the first side surface 2193, or between the second side surface 2195 and another battery pack BG1 closest to the second side surface 2195 may be different from the thickness of the pad 118 between each of the battery packs BG1, BG2, BG3, BG4, and BG5.

[0102] On the other hand, the heat dissipation portion 295 may be located between the receiving bottom surface 2191 and the plurality of battery cells 110 in the receiving space 291 as the inner space of the housing 210 .

[0103] The heat dissipation portion 295 may be configured to support or fix the plurality of battery cells 110. To this end, the heat dissipation portion 295 may be a polymer of an adhesive material. For example, the heat dissipation portion 295 may be a thermal adhesive.

[0104] In addition, the heat dissipation portion 295 may be formed of a thermally conductive material having excellent thermal conductivity to discharge heat generated in the plurality of battery cells 110 to the outside.

[0105] Similar to a general adhesive, the heat dissipation portion 295 may be coated or sprayed onto the receiving bottom surface 2191 in a liquid state with viscosity. After a predetermined curing time, the heat dissipation portion 295 may be phase-changed into a solid state.

[0106] In addition, when the heat dissipation portion 295 is not completely cured, the plurality of battery cells 110 and the pad portion 118 may be arranged in the accommodation space 291, so that when the heat dissipation portion 295 is cured, the heat dissipation portion 295 may fix the plurality of battery cells 110. Therefore, before the heat dissipation portion 295 is cured, the heat dissipation portion 295 may penetrate between the plurality of battery cells 110 and the pad portion 118.

[0107] Specifically, when the heat dissipation part 295 is cured, the heat dissipation part 295 can contact the pad bottom surface 1183 facing the accommodating bottom surface 2191 in the surface of the pad part 118, the main body bottom surface 1153 facing the accommodating bottom surface 2191 in the surface of each of the main bodies 115, and the accommodating bottom surface 2191.

[0108] To this end, the heat dissipation portion 295 may be formed of a thermally conductive adhesive material. For example, the heat dissipation portion 295 may be formed of a polymer material such as polyurethane, epoxy resin, or silicone resin. However, the heat dissipation portion 295 may use any material as long as it has thermal conductivity and adhesiveness.

[0109] Figure 3 is an example of enlarging the pad portion 118 according to the present disclosure.

[0110] Reference Figure 3 The pad portion 118 may have a pad or sheet shape having a predetermined thickness along the stacking direction. Figure 1 The battery cell 110 may include a main body surface 1151 and a main body second surface (not shown) arranged along the stacking direction.

[0111] When the pad 118 is located between the plurality of battery cells 110 , the pad 118 is configured to contact one main body surface 1151 of any one battery cell 110 and two main body surfaces of another battery cell 110 .

[0112] The pad portion 118 may be formed of one material, or may have a form in which a plurality of materials are stacked.

[0113] If the pad portion 118 is formed of a plurality of materials, the pad portion 118 may include: an inner layer portion 1181, which is located at the center of the pad portion along the stacking direction; and outer layer portions 1182, which are stacked on both sides of the inner layer portion 1181. Therefore, each of the outer layer portions 1182 may contact the main body surface 1151 of any one of the battery cells 110 and the main body surfaces of another battery cell 110. Specifically, the outer layer surface 1185, which is the surface of the outer layer portion 1182, may contact the main body surface 1151 of any one of the battery cells 110 or the main body surfaces of another battery cell 110.

[0114] The pad 118 may be formed of an elastic material. This is to allow the pad 118 to pressurize the battery cell 110 at a pressure above the surface pressure value without damaging the battery cell 110. As an example, the pad 118 may be formed of a polymer material of the polyurethane, silicone, and rubber series. However, the material of the pad 118 is not limited thereto.

[0115] If the cushion portion 118 is formed by stacking a plurality of materials, the inner layer portion 1181 may be formed of a polymer material of the polyurethane, silicone, and rubber series, and the outer layer portion 1182 may be formed of a heat-resistant material or a flame-retardant material.

[0116] Figure 4 Various embodiments according to changes in the surface hardness of the heat dissipation portion 295 and the pad portion 118 are shown.

[0117] In addition, unless otherwise specified, Figure 4 The embodiment described in the embodiment can also be applied to the bus bar assembly 300 (refer to Figure 6 ) is another example.

[0118] The pad 118 may be located between any two of the plurality of battery cells 110. Alternatively, the pad 118 may be located between battery groups BG1, BG2, BG3, BG4, and BG5 that group a portion of adjacent battery cells of the plurality of battery cells 110.

[0119] In addition, the pad portion 118 may be located between a side surface of the housing 210 and a battery cell 110 that is closest to a side surface of the housing 210 along the stacking direction among the plurality of battery cells 110. In other words, the pad portion 118 may be located between the plurality of battery cells 110 and a side of the housing 210 that faces the plurality of battery cells 110 in a direction perpendicular to the stacking direction.

[0120] On the other hand, the heat dissipation portion 295 is located between the pad bottom surface 1183, the main body bottom surface 1153 and the accommodating bottom surface 2191. The heat dissipation portion 295 can contact and fix the main body bottom surface 1153 and the pad bottom surface 1183. Different from this, the pad portion 118 can contact but not fix with one side 1151 or two sides of the main body, and pressurize each of the main body portions 115. As a result, the risk of damage to the battery cell 110 may increase.

[0121] That is, when the difference in surface hardness between the pad portion 118 and the heat dissipation portion 295 is large, the pressure applied to one surface of each of the main body portions 115, specifically, the surface pressure, may be different. The imbalance of the surface pressures that differ according to positions or regions in one main body portion 115 may cause stress concentration at a specific position or region, which may eventually lead to bag damage or the gas that is inevitably generated inside the main body portion 115 cannot be smoothly discharged, thereby adversely affecting the battery life.

[0122] In order to solve these problems, in the battery assembly 200 according to the present disclosure, the absolute value of the difference between the surface hardness of the heat dissipation portion 295 and the surface hardness of the pad portion 118 may be less than or equal to a predetermined allowable value.

[0123] Surface hardness is one of the physical properties that indicates the degree of softness or hardness of a surface. It can also be referred to as hardness. There are many ways to measure the hardness of an object. For example, there are Vickers Hardness, Brinell Hardness, Rockwell Hardness, Shore Hardness and other measurement methods. These are just different measurement methods, and the hardness of each hardness measurement method can be converted into the hardness of other hardness measurement methods.

[0124] In particular, Shore hardness is a widely used hardness measurement method because it can be used to simply measure surface hardness using a Shore durometer. Shore hardness can be divided into types such as D, A, and OO according to the shape of the tip of the indenter that is pressed into the surface of the object. Shore D hardness can be used for relatively hard surfaces, and Shore A hardness can be used for relatively soft surfaces. In addition, Shore D hardness values ​​and Shore A hardness values ​​can be converted to each other.

[0125] Figure 4The possibility of damage to the main body portion 115 after measuring the Shore hardness of the surfaces of the heat dissipation portion 295 and the pad portion 118 is shown.

[0126] Embodiment 1 is an example in which the surface hardness of the heat dissipation portion 295 is relatively harder than the surface hardness of the pad portion 118 .

[0127] In Example 2, the difference between the surface hardness of the heat dissipation portion 295 and the surface hardness of the pad portion 118 is relatively smaller than that of Example 1. In addition, in Example 2, the surface hardness of the heat dissipation portion 295 is relatively softer than that of Example 1.

[0128] In Example 3, the surface hardness of the heat dissipation portion 295 is relatively softer than the surface hardness of the pad portion 118 compared to Example 1. In addition, in Example 3, the surface hardness of the pad portion 118 is relatively hard compared to Example 2.

[0129] If only the difference in surface hardness between the heat dissipation portion 295 and the pad portion 118 is considered, Embodiment 1 and Embodiment 3 are examples in which the difference in surface hardness between the heat dissipation portion 295 and the pad portion 118 is relatively larger than that of other embodiments.

[0130] Embodiments 4 and 5 are examples in which the difference in surface hardness between the heat dissipation portion 295 and the pad portion 118 is smaller than in Embodiments 1 and 3 but larger than in Embodiment 2. In addition, Embodiments 4 and 5 are examples in which the heat dissipation portion 295 and the pad portion 118 have different surface hardness values ​​but the same surface hardness difference.

[0131] Reference Figure 4 It can be seen that in the case of Example 1, the main body 115 is likely to be damaged. That is, the difference in surface hardness between the heat dissipation portion 295 and the pad portion 118 may cause uneven surface pressure on the main body 115. Ultimately, the uneven surface pressure of the main body 115 may cause damage to the lower part of the main body 115. Specifically, the main body bottom surface 1153 may be damaged.

[0132] On the other hand, it can be seen that in the cases of Examples 2 to 5, when the absolute value of the difference between the surface hardness of the heat dissipation portion 295 and the surface hardness of the pad portion 118 is less than the allowable value, the risk of damage to the main body portion 115 is reduced.

[0133] However, in the case of Example 3, considering that the surface pressure of the main body 115 is still uneven, preferably, based on the Shore A hardness, the absolute value of the surface hardness difference between the heat dissipation portion 295 and the pad portion 118 is less than or equal to 50.

[0134] Referring to Example 1, when the surface hardness value of the pad portion 118 is Shore A 30 and the surface hardness value of the heat dissipation portion 295 is Shore D 60, the absolute value of the surface hardness difference between the pad portion 118 and the heat dissipation portion 295 is 80 based on the Shore A hardness. Example 1 is an example in which the pad portion 118 is relatively soft and the heat dissipation portion 295 is extra hard. It can be seen that due to the large difference in surface hardness between the pad portion 118 and the heat dissipation portion 295, the main body 115 is damaged.

[0135] Referring to Example 2, it can be seen that when the absolute value of the surface hardness difference between the heat dissipation portion 295 and the pad portion 118 is 30 based on the Shore A hardness, the main body portion 115 is not damaged.

[0136] Embodiment 3 is another example in which the absolute value of the difference in surface hardness between the heat dissipation portion 295 and the pad portion 118 is greater than 50 based on the Shore A hardness. Specifically, Embodiment 3 is an example in which the absolute value of the difference in surface hardness between the pad portion 118 and the heat dissipation portion 295 is 65 based on the Shore A hardness. When the pad portion 118 is a material having a surface hardness of Shore D 75, such as mica, it can be seen that surface pressure imbalance occurs in the main body portion 115.

[0137] On the other hand, in the case of Examples 4 and 5, the absolute value of the difference in surface hardness between the heat dissipation portion 295 and the pad portion 118 is less than or equal to 50 based on Shore A hardness. It can be seen that the main body 115 is not damaged even in this case.

[0138] In addition, by checking the results of the state of health (SOH) of the battery cell 110 measured after being placed at a predetermined temperature higher than room temperature for 30 days, it can be seen that in Example 1 and Example 3, the surface hardness difference between the heat dissipation part 295 and the main body 115 is large compared with other examples, so the SOH of the battery cell 110 is relatively reduced.

[0139] The reason for the sudden drop in the capacity of the battery cell 110 is that the pressure applied to the main body 115, i.e., the surface pressure, is uneven due to the difference in surface hardness between the heat dissipation portion 295 and the pad portion 118. The uneven surface pressure or surface pressure deviation of the main body 115 is due to the uneven accumulation of gas generated inside the main body 115 in a specific area, which may cause the positive and negative electrodes of the electrode assembly to warp. Ultimately, this will become a factor in reducing the SOH of the battery cell 110, and the life of the battery cell 110 will also be shortened.

[0140] Reference Figure 4In the second, fourth and fifth embodiments, it can be seen that the smaller the absolute value of the difference between the surface hardness of the heat dissipation part 295 and the surface hardness of the pad part 118, the less likely the main body 115 is to be damaged, and the capacity of the battery cell 110 is almost unchanged. On the other hand, it can be seen that in the case of the first and third embodiments, the capacity of the battery cell 110 is 87% and 85%, respectively, and the capacity has changed.

[0141] According to Embodiment 2, Embodiment 4 and Embodiment 5, preferably, based on Shore A hardness, the absolute value of the surface hardness difference between the pad portion 118 and the heat dissipation portion 295 is less than or equal to 50. Of course, the error in measuring the surface hardness can also be considered here.

[0142] On the other hand, as described above, when the absolute value of the surface hardness difference between the pad portion 118 and the heat dissipation portion 295 according to the present disclosure is less than or equal to 50 based on Shore A, the surface pressure imbalance of the main body portion 115 can be minimized. The surface pressure imbalance minimization means that the absolute value of the surface pressure difference measured in the first area and the second area of ​​the battery cell 110 is less than or equal to a predetermined allowable pressure value. In other words, the surface pressure difference between any two areas of the main body portion 115 can be less than or equal to the allowable pressure value.

[0143] Alternatively, when the surface hardness difference between the pad portion 118 and the heat dissipation portion 295 is less than or equal to the allowable value, the surface pressure difference between any two regions of the main body portion 115 may be less than or equal to the allowable pressure value.

[0144] Figure 5 A cross section of the bus bar frame 155 , the bus bar 151 , the contact portion 159 , and the lead tab portion 111 viewed from the Z direction is shown.

[0145] Reference Figure 1 and Figure 5 The battery assembly 200 may include: a battery cell stack including a plurality of battery cells 110 stacked along the stacking direction and a bus bar assembly 150 for electrically connecting the plurality of battery cells 110 to the outside; and a housing 210 accommodating the battery cell stack 100 therein.

[0146] The busbar assembly 150 may include: a busbar 151, electrically connected to each of the lead joint parts 111; a busbar frame 155, located between the busbar 151 and each of the main body parts 115 to support the busbar 151; a through hole 1559, formed through the busbar frame 155 in a direction from the main body part 115 toward the busbar 151, so that each of the lead joint parts 111 is inserted into the through hole 1559; and a contact part 159, located between the inner side surface 1559a of the through hole and the lead joint part 111, and in contact with the through hole 1559 and the lead joint part 111.

[0147] The bus bar frame 155 may electrically insulate the bus bar 151 from the battery cells 110 and support the bus bar 151. To this end, the bus bar frame 155 may be located between the battery cells 110 and the bus bar 151.

[0148] Specifically, the busbar frame 155 may be located between each of the main body portions 115 and the busbar 151 , and each lead joint portion 111 protruding from each of the main body portions 115 may be connected to the busbar 151 after being inserted into a through hole 1559 provided in the busbar frame 155 .

[0149] In addition, the absolute value of the difference between the surface hardness of the contact portion 159 and the surface hardness of the bus bar frame 155 may be less than or equal to a predetermined difference. As described above, this is to prevent the bus bar frame 155 and the plurality of battery cells 110 from being damaged by making the surface pressure difference applied to each component less than or equal to the difference, and to guide the gas generated inside the plurality of battery cells 110 to be discharged in a predetermined direction.

[0150] The difference may be the same as the allowable value based on Shore A hardness.

[0151] On the other hand, the lead joint portion 111 may include: a lead joint (not shown) made of a metal material for electrically connecting to the electrode assembly; and a lead film 1111 or a sealant for electrically insulating the lead joint and the main body portion 115 and sealing a protruding portion of the lead joint.

[0152] In addition, the through hole 1559 may extend in the height direction of the housing 210. A plurality of through holes 1559 are provided, and each of the lead joints 111 corresponds to each other, so that each lead joint 111 can be inserted into each of the plurality of through holes 1559. Each lead joint 111 is connected to the bus bar 151 after being inserted into each through hole 1559.

[0153] The bus bar 151 may include a bonding area 1519 in the form of a groove or a hole for electrical connection with the lead tab part 111. By inserting each of the lead tab parts 111 into the bonding area 1519, the bus bar 151 and the plurality of battery cells 110 may be electrically connected.

[0154] In another embodiment, the lead joint portion 111 may include a region where the lead joint portion 111 is bent into a U shape within a predetermined distance from the free end of the lead joint portion 111. And the bonding region may be hole-shaped. Therefore, when the U-shaped bent region is inserted into the bonding region 1519, the bent region may act as a stopper and may more stably maintain electrical connection with the bus bar 151.

[0155] On the other hand, after the lead tab 111 is inserted into the through hole 1559, the length of the through hole 1559 in the direction from the main body 115 toward the bus bar 151 may be smaller than the protruding length of the lead tab 111. A predetermined gap may exist between the inner side surface 1559a of the through hole and the lead tab 111.

[0156] In order to fill the gap, the battery assembly 200 may include a contact portion 159 , which is disposed between the inner side surface 1559 a of the through hole and the lead joint portion 111 , and may contact the inner side surface 1559 a of the through hole and the lead joint portion 111 at the same time.

[0157] In addition, since the gap can be formed on both sides with the lead joint portion 111 as the center, the lead joint portion 111 can pass through the contact portion 159. Different from this, the contact portion 159 may include a first sub-contact portion (not shown) and a second sub-contact portion (not shown) separated, and the first sub-contact portion and the second sub-contact portion may be respectively located in two gaps formed between the lead joint portion 111 and the inner side surface 1559a of the through hole.

[0158] Since the through holes 1559 can be provided to match the number of each of the lead joint parts 111 , the contact parts 159 can also be provided in the same number.

[0159] On the other hand, the contact portion 159 may be formed of a polymer material in a foam form. In addition, the material of the contact portion 159 may have elasticity and electrical insulation. In the direction from the main body 115 toward the bus bar 151, the length of the contact portion 159 is less than or equal to the length of the inner side surface of the through hole 1559, so that when the contact portion 159 is inserted into the through hole 1559, it will not protrude from the bus bar frame 155 to the main body 115.

[0160] The absolute value of the difference in surface hardness between the contact portion 159 and the busbar frame 155 may be less than or equal to the difference. Similarly, the absolute value of the difference in surface hardness between the contact portion 159 and the lead joint portion 111 (specifically the lead film 1111) may be less than or equal to the difference. In addition, the absolute value of the difference in surface hardness between the lead joint portion 111 (specifically the lead film 1111) and the busbar frame 155 may be less than or equal to the difference.

[0161] Thus, the main body 115, in particular, the protruding first surface 1155 (see FIG. 1 ) of the main body 115 from which the lead connector 111 protrudes. Figure 1 )’s surface pressure can be uniform.

[0162] In addition, the surface pressure applied to the protruding second surface (not shown) located in the opposite direction of the protruding first surface 1155 may also be uniform.

[0163] In addition, the difference may be equal to the allowable value. Thus, the surface pressure applied to the main body surface 1151, the main body second surface (not shown), the main body bottom surface 1153, the protruding first surface 1155 and the protruding second surface (not shown) can be uniform. This means that the gas that may be generated inside each of the battery cells 110 can be discharged along the height direction of the shell 210 toward the direction where the main body upper surface 1159 of the upper surface of the main body 115 is located.

[0164] Figure 6 Another example of a battery assembly 300 according to the present disclosure is schematically illustrated.

[0165] Reference Figure 6 Another example of the battery assembly 300 according to the present disclosure may be in the form of a battery pack. That is, the battery assembly 300 includes: a housing 310, accommodating a plurality of battery cells 110; an accommodating bottom surface 3191, forming the bottom surface of the housing 310; a heat dissipation portion 395, located between the plurality of battery cells 110 and the accommodating bottom surface 3191; and a pad portion 118 (refer to Figure 1), located between the plurality of battery cells 110. Moreover, based on Shore A hardness, the absolute value of the difference between the surface hardness of the heat dissipation portion 395 and the surface hardness of the pad portion 118 may be less than or equal to 50.

[0166] Figure 6 The figure is a diagram of the housing 310 viewed from above, which is an example in which the housing cover (not shown) forming the top surface of the housing space 319 is removed. Figure 6 , the battery assembly 300 may be located at the lower part of the electric vehicle, so the outer shape of the housing 310 may have an asymmetrical shape. However, in contrast, the housing 310 may have a symmetrical shape, such as a rectangular shape. That is, Figure 6 Only features necessary for explaining the battery assembly 300 according to the present disclosure are shown in an exaggerated manner, and portions having little relevance to the necessary features are shown schematically.

[0167] On the other hand, a receiving space 319 for receiving the plurality of battery cells 110 may be formed inside the housing 310 .

[0168] The battery assembly 300 may include a partition frame 330 for partitioning the accommodation space 319. The partition frame 330 may partition the accommodation space 319 into a plurality of spaces. The plurality of battery cells 110 may be partitioned and disposed in the plurality of spaces according to a predetermined number.

[0169] In addition, the partition frame 330 may play a role in reinforcing the strength of the housing 310. To this end, the partition frame 330 may include a first frame 333 and a second frame 335 located between the battery cells 110 partitioned by a predetermined number. When viewed from above, the first frame 333 and the second frame 335 may partition the accommodation space 319 in the horizontal direction (X direction) and the vertical direction (Y direction).

[0170] The heat dissipation portion 395 may be Figures 1 to 5 On the other hand, when viewed from above, Figure 6 The relative area of ​​the heat dissipation portion 395 is exaggerated to indicate that the heat dissipation portion 395 is located between the plurality of battery cells 110 and the receiving bottom surface 3191 .

[0171] That is, when the battery assembly 300 is viewed from above, the area of ​​the heat dissipation portion 395 coated on the receiving bottom surface 3191 may be smaller than the area of ​​the battery cells 110 arranged in a predetermined number through the partition frame 330 and projected onto the receiving bottom surface 3191. That is, the heat dissipation portion 395 may be located on the receiving bottom surface 3191 so that only the main body 115 (refer to Figure 1 ) is in contact with the heat dissipation portion 395.

[0172] In addition, the battery assembly 300 may further include a control unit 650 for measuring the voltage and / or temperature of the plurality of battery cells 110 or controlling electrical connection and disconnection of the plurality of battery cells 110 .

[0173] The present disclosure can be implemented in various modified forms, and the scope of rights of the present disclosure is not limited to the above-mentioned embodiments. Therefore, if the modified embodiments include the constituent elements of the claims of the present disclosure, they should be deemed to belong to the scope of rights of the present disclosure.

Claims

1. A battery assembly comprising: A housing for accommodating a plurality of battery cells; A receiving bottom surface, forming the bottom surface of the shell; A heat dissipation portion, located between the plurality of battery cells and the accommodating bottom surface; as well as The pad is located between a plurality of battery groups in which at least one of the plurality of battery cells is grouped according to a predetermined number of battery cells. Based on Shore A hardness, an absolute value of a difference between a surface hardness of the heat dissipation portion and a surface hardness of the pad portion is less than or equal to 50.

2. The battery assembly according to claim 1, wherein: The pad portion is deformed according to expansion and contraction of a battery cell adjacent to the pad portion.

3. The battery assembly according to claim 1, wherein: The heat dissipation portion includes a heat conductive material.

4. The battery assembly according to claim 3, wherein: The heat dissipation portion includes an adhesive material.

5. The battery assembly according to claim 4, wherein: The heat dissipation part is coated on the receiving bottom surface in a viscous liquid state, and then solidifies into a solid state after a predetermined time.

6. The battery assembly according to claim 1, wherein: The plurality of battery cells are stacked along a predetermined stacking direction, Each of the plurality of battery cells comprises: a main body portion accommodating an electrode assembly for storing or generating electrical energy; and a lead connector portion, electrically connected to the electrode assembly and protruding to the outside of the main body portion in a direction perpendicular to the stacking direction, The pad portion is in contact with main bodies of a portion of the battery cells that are closest to the pad portion.

7. The battery assembly according to claim 6, wherein: The heat dissipation portion is in contact with the accommodation bottom surface, a pad bottom surface of the pad portion facing the accommodation bottom surface, and a main body bottom surface of the main body portion facing the accommodation bottom surface.

8. The battery assembly according to claim 6, wherein: The pad portion is provided with a plurality of The plurality of pads pressurize one surface of each of the main bodies at a pressure equal to or greater than a predetermined surface pressure value.

9. The battery assembly according to claim 6, wherein: The main body comprises: One side of the main body faces the stacking direction; The second side of the main body faces the first side of the main body; and The bottom surface of the main body is connected to the one side of the main body and the second side of the main body and faces the containing bottom surface. The absolute value of the pressure difference applied to the one surface of the main body, the second surface of the main body and the bottom surface of the main body through the pad part and the heat dissipation part is less than or equal to a predetermined allowable pressure.

10. The battery assembly according to claim 1, wherein: The pad portion is formed by stacking different materials.

11. The battery assembly according to claim 10, wherein: The pad portion comprises: an inner layer portion having a flat plate shape and formed of a polymer material; and The outer layer part is bonded to both surfaces of the inner layer part, and is formed of a flame retardant material.

12. The battery assembly according to claim 1, further comprising: The bus bar assembly is located inside the housing and electrically connects the plurality of battery cells to the outside.

13. The battery assembly according to claim 12, wherein: Each of the plurality of battery cells comprises: A main body portion, which contains an electrode assembly for storing or generating electrical energy; and a lead connector portion protruding from the inside of the main body portion to the outside to connect the electrode assembly and the bus bar, The bus bar assembly comprises: A bus bar electrically connected to each of the lead connector portions; a bus bar frame, located between the bus bar and each of the main body portions to support the bus bar; a through hole formed through the bus bar frame in a direction from the main body toward the bus bar so that each of the lead tab portions is inserted into the through hole; and a contact portion, located between the inner side surface of the through hole and the lead connector portion, and in contact with the through hole and the lead connector portion, An absolute value of a difference between a surface hardness of the contact portion and a surface hardness of the busbar frame is less than or equal to a predetermined difference.

14. The battery assembly according to claim 13, wherein: The contact portion has a foamed form of a polymer material.

15. The battery assembly according to claim 13, wherein: Along a direction from the main body toward the bus bar, a length of an inner side surface of the through hole is greater than or equal to a length of the contact portion.

16. A battery assembly comprising: A plurality of battery cells are arranged in one direction, each of the plurality of battery cells comprises: a main body portion, storing or generating electric energy inside; a lead connector protruding from the inside of the main body portion to the outside of the main body portion; a lead film located in an area of ​​the outer side surface of the lead connector that contacts the main body portion, so as to insulate the lead connector from the main body portion; a bus bar extending in the one direction and electrically connected to each of the lead terminals; a bus bar frame, located between the bus bar and each of the main body portions to support the bus bar; a plurality of through holes formed through the bus bar frame, each of the lead tabs being inserted into the through hole; and a plurality of contact portions located in the plurality of through holes and contacting each of the lead films, Based on Shore A hardness, an absolute value of a difference between a surface hardness of each of the lead films and a surface hardness of each of the contact portions is less than or equal to 50.

17. The battery assembly according to claim 16, wherein: Based on Shore A hardness, an absolute value of a difference between a surface hardness of each of the contact portions and a surface hardness of the busbar frame is less than or equal to 50.

18. A battery assembly comprising: A housing for accommodating a plurality of battery cells; A receiving bottom surface, forming the bottom surface of the shell; A heat dissipation portion, located between the plurality of battery cells and the accommodating bottom surface; as well as A pad portion is located between the plurality of battery cells, Based on Shore A hardness, an absolute value of a difference between a surface hardness of the heat dissipation portion and a surface hardness of the pad portion is less than or equal to 50.

19. A battery assembly comprising: A housing for accommodating a plurality of battery cells; A receiving bottom surface, forming the bottom surface of the receiving space; A partition frame is used to divide the accommodation space into a plurality of spaces; A heat dissipation portion, located between the plurality of battery cells and the accommodating bottom surface; as well as A pad portion is located between the plurality of battery cells, Based on Shore A hardness, an absolute value of a difference between a surface hardness of the heat dissipation portion and a surface hardness of the pad portion is less than or equal to 50.

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