Battery cell and manufacturing method thereof

Abstract

A battery cell is disclosed. The battery cell comprises an electrode assembly; a pouch formed of a pouch sheet and including an accommodating portion for accommodating the electrode assembly; and a curing agent, the bag including a folded portion including a first folded joint portion and a second folded joint portion formed of the bag sheet and facing and contacting each other, the folded portion including: a folded body extending from the accommodating portion; and a folding tail portion extending from the folding main body and folded to face the folding main body, the folding main body being bent such that the curing agent is located between the folding tail portion and the accommodating portion. According to one embodiment of the present disclosure, a folded portion, which is a portion of a pouch that wraps an electrode assembly and is sealed, is folded and bonded to a receiving portion by a curing agent.

Description

Technical Field

[0001] This disclosure relates to a battery cell and a method for manufacturing the same. Background Technology

[0002] In the case of battery cells used in pouches, gas may concentrate in a folded section of the pouch during thermal runaway. Furthermore, the insulation of the battery cell may be compromised when the folded sections of the pouch are loosened or pressed. Therefore, effective sealing of the folded sections of the pouch is necessary. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] One technical problem this disclosure aims to solve is to provide a battery cell with a sealing method for the folded portion of a bag reinforced by a curing agent.

[0005] (II) Technical Solution

[0006] According to the present disclosure, the battery cell may include: an electrode assembly; a bag formed of a bag sheet and including a receiving portion for accommodating the electrode assembly; and a curing agent, the bag including a fold portion comprising a first fold joint and a second fold joint formed of the bag sheet and facing each other and abutting each other, the fold portion including: a fold body extending from the receiving portion; and a fold tail extending from the fold body and folded to face the fold body, and the fold body being bent such that the curing agent can be located between the fold tail and the receiving portion.

[0007] The bag sheet can form an inner side and an outer side, and the inner side of the first folded joint can be joined to the inner side of the second folded joint.

[0008] The bag sheet may include: an inner layer forming the inner side of the bag; an outer layer forming the outer side of the bag; and a middle layer located between the inner layer and the outer layer, wherein the inner layer, the middle layer and the outer layer may be stacked sequentially.

[0009] The receiving portion may include a first receiving portion and a second receiving portion, which are formed from the bag sheet and extend along the length direction and are spaced apart from each other in the width direction. The bag may include a connecting portion, which is formed from the bag sheet and connects the first receiving portion and the second receiving portion, and extends from the first receiving portion to the second receiving portion.

[0010] The first folding joint can extend from the first receiving portion along the width direction, and the second folding joint can extend from the second receiving portion along the width direction.

[0011] The electrode assembly may be located between the folded portion and the connecting portion.

[0012] The bag may include: a first lead wire connection portion formed of the bag sheet and extending from the first receiving portion along the length direction; and a second lead wire connection portion formed of the bag sheet, extending from the second receiving portion along the length direction and bonded to the first lead wire connection portion.

[0013] The battery cell may further include: electrode leads extending from the electrode assembly along the length direction, and the electrode leads may be located between the first lead joint and the second lead joint.

[0014] The curing agent can be cured by ultraviolet light irradiation.

[0015] The curing agent can be cured by accepting pressures of 280 kPa to 300 kPa.

[0016] According to the battery cell manufacturing method disclosed herein, the steps may include: accommodating an electrode assembly in a receiving portion of a bag formed from a bag sheet, and folding the bag to join a first fold joint and a second fold joint extending from the receiving portion, thereby sealing the bag; and bonding the fold formed by the joining of the first fold joint and the second fold joint using a curing agent.

[0017] The fold portion may include: a fold body extending from the receiving portion; and a fold tail extending from the fold body. The step of bonding the fold portion may include: a first fold portion folding step, folding the fold tail so that the fold tail faces the fold body.

[0018] The bonding step may include: a second folding and curing agent application step, bending the folded portion so that the folded portion faces the receiving portion, and placing the curing agent between the folded portion and the receiving portion.

[0019] The curing agent may be located between the folded tail and the receiving portion.

[0020] The bonding step may include a curing step, in which the curing agent is cured.

[0021] During the curing step, a pressure of 280 kPa to 300 kPa may be applied to the curing agent.

[0022] In the curing step, ultraviolet light may be applied to the curing agent.

[0023] During the curing step, the curing agent can be maintained at a temperature of 180°C to 200°C.

[0024] The receiving portion may include a first receiving portion and a second receiving portion, the first receiving portion and the second receiving portion extending along the length direction and spaced apart in the width direction, the first folding joint portion extending from the first receiving portion along the width direction, and the second folding joint portion extending from the second receiving portion along the width direction.

[0025] The bag may further include a connecting portion that connects the first receiving portion and the second receiving portion and extends from the first receiving portion to the second receiving portion, and the electrode assembly may be located between the connecting portion and the folded portion.

[0026] (III) Beneficial Effects

[0027] According to one embodiment of this disclosure, a battery cell with a sealing of the folded portion of a bag reinforced by a curing agent and a method thereof can be provided.

[0028] The battery cell and manufacturing method disclosed herein can be used in eco-friendly electric vehicles, hybrid vehicles, etc., to prevent climate change by suppressing air pollution and greenhouse gas emissions. Attached Figure Description

[0029] Figure 1 This is a diagram showing the bag sheet.

[0030] Figure 2 It shows that Figure 1 The diagram shows a cross-section of the bag sheet taken along line A1-A2.

[0031] Figure 3 It is shown as a bag Figure 1 The diagram shows the state of the bag sheet being processed.

[0032] Figure 4 It shows that Figure 3 The diagram shows a cross-section of the bag taken along line B1-B2.

[0033] Figure 5 This is a diagram illustrating a battery cell according to one embodiment of the present disclosure.

[0034] Figure 6 It shows that Figure 5 The diagram shows a cross-section of the battery cell taken along line C1-C2.

[0035] Figure 7 It is shown Figure 6The diagram shown in Figure D illustrates the state in which the folded tail bends from the folded body.

[0036] Figure 8 It is shown Figure 7 The diagram shows the folded portion in a folded state.

[0037] Figure 9 It is shown Figure 8 The diagram shows a state where the folded portion bends toward the receiving portion, and the curing agent is located between the folded portion and the receiving portion.

[0038] Figure 10 It shows that Figure 9 The graph shown is a result of an experiment on the curing agent under pressure conditions.

[0039] Figure 11 This is a flowchart illustrating a cell manufacturing method according to an embodiment of the present disclosure.

[0040] Figure 12 This is a flowchart illustrating the bonding steps of the folded parts.

[0041] Figure 13 It shows the basis Figure 9 The diagram shows the state of the battery cell with the coating ratio of the curing agent shown. Detailed Implementation

[0042] The following is for reference Figures 1 to 13 This disclosure will be described in detail. However, this is merely exemplary and is not limited to the specific embodiments described herein.

[0043] The XYZ coordinate system may be used in this specification. The XYZ coordinate system may be a Cartesian coordinate system.

[0044] For example, the Z-axis can be parallel to the up and down directions. For example, a positive Z-axis direction can represent the upward direction. For example, a negative Z-axis direction can represent the downward direction.

[0045] For example, the X-axis can be parallel to the forward and backward directions. For example, the positive X-axis direction can represent the forward direction. For example, the negative X-axis direction can represent the backward direction.

[0046] For example, the Y-axis can be parallel to the left and right directions. For example, a positive Y-axis direction can represent the left direction. For example, a negative Y-axis direction can represent the right direction.

[0047] Figure 1 This is a diagram showing the bag sheet. Figure 2 It shows that Figure 1 The diagram shows a cross-section of the bag sheet taken along line A1-A2. The battery bag 10 may be referred to as a "bag".

[0048] Reference Figure 1 and Figure 2 The battery pouch 10 may include a pouch sheet 100. For example, the battery pouch 10 can be formed by processing the pouch sheet 100. For example, the battery pouch 10 can be formed by pressing the pouch sheet 100.

[0049] The bag sheet 100 can be formed into a sheet shape. For example, the bag sheet 100 can be formed into a plane shape before being processed. For example, the bag sheet 100 can be formed into two sides.

[0050] For example, the inner side 100i of the bag can be one side of the bag sheet 100. For example, the outer side 100t of the bag can be the other side of the bag sheet 100. The thickness of the bag sheet 100 can be the distance between the inner side 100i and the outer side 100t of the bag.

[0051] The bag sheet 100 can be formed into a multi-layered structure. For example, the bag sheet 100 can be formed into a structure with an inner layer 110, a middle layer 120 and an outer layer 130 stacked together.

[0052] For example, the bag sheet 100 may include an inner layer 110. The inner layer 110 may form the inner side 100i of the bag. The inner layers 110 may overlap and be joined.

[0053] The inner layer 110 may be formed of an electrically insulating material. For example, the inner layer 110 may be formed of a material containing polypropylene (PP).

[0054] The bag sheet 100 may include an outer layer 130. The outer layer 130 may form the outer side 100t of the bag. The outer layer 130 may be formed of a waterproof and insulating material. For example, the outer layer 130 may be formed of a material containing polycarbonate (PC).

[0055] The bag sheet 100 may include an intermediate layer 120. The intermediate layer 120 may be located between the inner layer 110 and the outer layer 130.

[0056] The intermediate layer 120 can be rigid. For example, the intermediate layer 120 can be formed of a metallic material. For example, the intermediate layer 120 can maintain its shape.

[0057] Figure 3 It is shown as a bag Figure 1 The diagram shows the state of the bag sheet being processed. Figure 4It shows that Figure 3 The diagram shows a cross-section of the bag taken along line B1-B2.

[0058] Reference Figures 1 to 4 , Figure 1 The bag sheet 100 shown can be pressed. When pressing the bag sheet 100 (refer to...) Figure 1 When the bag sheet is 100 (refer to...), Figure 1 The shape can change and then remain the same.

[0059] The bag 10 may include a receiving portion 200. The receiving portion 200 may be provided in multiple ways. For example, the bag 10 may include a first receiving portion 200a and a second receiving portion 200b. The receiving portion 200 may include or represent at least one of the first receiving portion 200a and the second receiving portion 200b.

[0060] The inner side 100i of the receiving portion 200 may be recessed, and the outer side 100t of the receiving portion 200 may be protruding. The receiving portion 200 can accommodate an electrode assembly (not shown). For example, the inner side 100i of the receiving portion 200 may face the electrode assembly (not shown).

[0061] The receiving portion 200 can be formed into a shape that extends in one direction. For example, the extending direction of the receiving portion 200 can be the length direction of the receiving portion 200. For example, the length direction of the receiving portion 200 can be the left-right direction. For example, the length direction of the receiving portion 200 can be the Y-axis direction.

[0062] For example, the width direction of the receiving portion 200 may intersect the length direction of the receiving portion 200. For example, the width direction of the receiving portion 200 may be the front-to-back direction. For example, the width direction of the receiving portion 200 may be the X-axis direction. The first receiving portion 200a and the second receiving portion 200b may be provided in the width direction.

[0063] The bag 10 may include a connecting portion 300. The connecting portion 300 may be located between the first receiving portion 200a and the second receiving portion 200b. The connecting portion 300 may connect the first receiving portion 200a and the second receiving portion 200b. The inner side 100i of the connecting portion 300 may protrude, and the outer side 100t of the connecting portion 300 may be recessed.

[0064] The bag 10 may include a joint 400. Multiple joints 400 may be provided. For example, the bag 10 may include a lead joint 410 and a fold joint 420. The joint 400 may include or represent at least one of the lead joint 410 and the fold joint 420.

[0065] The lead wire connection portion 410 can be formed by extending from the receiving portion 200 along the length direction of the receiving portion 200. When the electrode assembly 20 (see reference) is received in the receiving portion 200 Figure 6 When the lead wire connection 410 is in contact with the electrode assembly 20 (see reference 20), the lead wire connection 410 can be connected to the electrode assembly 20 (see reference 20). Figure 6 ) Protruding electrode lead 30 (refer to) Figure 5 (Connected)

[0066] For example, a first lead joint 410a may be formed extending from a first receiving portion 200a along the length direction of the first receiving portion 200a. For example, a second lead joint 410b may be formed extending from a second receiving portion 200b along the length direction of the second receiving portion 200b. The lead joint 410 may include or represent at least one of the first lead joint 410a and the second lead joint 410b.

[0067] For example, the folded joint 420 can extend from the receiving portion 200 along the width direction to the outer edge of the bag sheet 100. The width direction can intersect the length direction. For example, the width direction can be parallel to the direction from the first receiving portion 200a to the second receiving portion 200b.

[0068] For example, the first folding joint 420a can extend from the first receiving portion 200a in the width direction to the outer edge of the bag sheet 100. For example, the second folding joint 420b can extend from the second receiving portion 200b in the width direction to the outer edge of the bag sheet 100.

[0069] The folding joint 420 may include or represent at least one of the first folding joint 420a and the second folding joint 420b. The first folding joint 420a, the first receiving part 200a, the second receiving part 200b and the second folding joint 420b may be arranged sequentially.

[0070] Figure 5 This is a diagram illustrating a battery cell according to one embodiment of the present disclosure. Figure 6 It shows that Figure 5 The diagram shows a cross-section of the battery cell taken along line C1-C2.

[0071] Reference Figure 5 and Figure 6 The thickness of the battery cell 1 can correspond to the distance between the first receiving portion 200a and the second receiving portion 200b. For example, the thickness of the battery cell 1 can be the length of the battery cell 1 with reference to the thickness direction of the battery cell 1.

[0072] The thickness direction of the battery cell 1 can be parallel to the direction from the first receiving portion 200a to the second receiving portion 200b. For example, the thickness direction of the battery cell 1 can be parallel to the Z-axis.

[0073] After the electrode assembly 20 is placed and housed in the first receiving part 200a, the bag 10 (refer to) Figure 3 and Figure 4 The bag 10 (refer to the reference) can be bent and folded at the joint 300. Figure 3 and Figure 4 When folded, bag 10 (refer to) Figure 3 and Figure 4 () can overlap.

[0074] Overlapping bags 10 (see reference) Figure 3 and Figure 4 ) inside the bag 100i (refer to) Figure 2 They can face each other. Overlapping bags 10 (see reference) Figure 3 and Figure 4 ) inside the bag 100i (refer to) Figure 2 They can be combined with each other. For example, overlapping bags 10 (see reference). Figure 3 and Figure 4 It can be combined and sealed.

[0075] For example, the first lead joint 410a (see reference) Figure 3 ) and second lead junction 410b (refer to Figure 3 They can face each other and be joined together. For example, the first fold joint 420a and the second fold joint 420b can face each other and be joined together.

[0076] Electrode leads 30 may protrude from electrode assembly 20 along its length. For example, electrode leads 30 may be coupled to electrode tabs (not shown) protruding from electrode assembly 20 along its length. For example, electrode leads 30 may be connected to electrode assembly 20 via electrode tabs (not shown).

[0077] Electrode lead 30 can pass through lead junction 410. For example, electrode lead 30 can pass through first lead junction 410a (see reference). Figure 3 ) and second lead junction 410b (refer to Figure 3 )between.

[0078] Electrode leads 30 may include or represent at least one of a left electrode lead 31 and a right electrode lead 32. The left electrode lead 31 may protrude to the left from the electrode assembly 20. The right electrode lead 32 may protrude to the right from the electrode assembly 20.

[0079] When the first folding joint 420a and the second folding joint 420b are combined, the folding joint 420 can be referred to as a "fold". The folding joint 420 can be located on the opposite side of the connecting part 300. For example, the electrode assembly 20 can be located between the folding joint 420 and the connecting part 300.

[0080] In a battery module (not shown) with multiple battery cells 1, the connecting portion 300 can contact the bottom surface of the battery module (not shown). In this case, when thermal runaway occurs in the battery cell 1, heat and gas may concentrate in the fold portion 420. Therefore, it is necessary to maintain the bonding force between the first folding joint portion 420a and the second folding joint portion 420b of the fold portion 420.

[0081] Figure 7 It is shown Figure 6 The diagram shown in Figure D illustrates the state in which the folded tail bends from the folded body. Figure 8 It is shown Figure 7 The diagram shows the folded portion in a folded state.

[0082] Reference Figures 6 to 8 The folding portion 420 can be divided into two regions. For example, the folding portion 420 may include a folding body 421 extending from the receiving portion 200.

[0083] For example, the fold portion 420 may include a fold tail portion 422 extending from the fold body 421. The fold portion 420 may be bent at the boundary between the fold body 421 and the fold tail portion 422. For example, the fold portion 420 may be bent toward the first receiving portion 200a at the boundary between the fold body 421 and the fold tail portion 422.

[0084] When the folding portion 420 is further bent, the folding portion 420 can be folded. For example, the folding body 421 and the folding tail 422 can face each other. For example, the first folding joint 420a of the folding body 421 and the first folding joint 420a of the folding tail 422 can face each other.

[0085] Figure 9 It is shown Figure 8 The diagram shows a state where the folded portion bends toward the receiving portion, and the curing agent is located between the folded portion and the receiving portion.

[0086] Reference Figure 8 and Figure 9 The folding portion 420 can be bent toward the receiving portion 200. For example, the folding portion 420 can be bent toward the first receiving portion 200a.

[0087] When the folding portion 420 bends toward the receiving portion 200, the folding tail portion 422 may face the receiving portion 200. For example, when the folding portion 420 bends toward the first receiving portion 200a, the folding tail portion 422 may face the first receiving portion 200a.

[0088] The curing agent 500 may be located between the folded portion 420 and the receiving portion 200. For example, the curing agent 500 may be located between the folded tail portion 422 and the receiving portion 200. For example, the curing agent 500 may be located between the folded tail portion 422 and the first receiving portion 200a.

[0089] Ultraviolet (UV) light can irradiate the curing agent 500. During the exposure of the curing agent 500 to UV light, at least one of heat and pressure can be applied to the curing agent 500. For example, at least one of heat and pressure can be applied to the folded portion 420. Through this process, the folded portion 420 can be fixed to the receiving portion 200.

[0090] Reference Figure 5 and Figure 9 The curing agent 500 can be distributed along the length direction of the battery cell 1. The length direction of the battery cell 1 can be the length direction of the receiving portion 200. As described above, the portion formed by the curing agent 500 can be referred to as the "cured portion".

[0091] For example, the cured portion 500 may be distributed along the boundary between the receiving portion 200 and the folded portion 420. For example, the cured portion 500 formed by the curing agent 500 may be integrally formed. For example, the cured portion 500 may extend from one end of the boundary between the receiving portion 200 and the folded portion 420 and connect to the other end.

[0092] As another example, the curing section 500 can be formed by a plurality of spaced-apart curing sections 500. For example, the plurality of curing sections 500 can be spaced apart from each other and arranged sequentially along the length direction of the cell 1.

[0093] For example, taking the length direction of the battery cell 1 as a reference, the total length of the plurality of cured portions 500 can be 40% to 60% of the length of the receiving portion 200. For example, taking the length direction of the battery cell 1 as a reference, the total length of the plurality of cured portions 500 can be 50% of the length of the receiving portion 200. Therefore, while appropriately maintaining the capacity of the curing agent 500, the bonding force between the folded portion 420 and the receiving portion 200 can be maintained by the curing agent 500.

[0094] Figure 10 It shows that Figure 9 The graph shown is a result of an experiment on the curing agent under pressure conditions.

[0095] Reference Figure 9 and Figure 10 Curing agent 500 can be cured according to Examples 1 to 3. Curing agent 500 can be exposed to ultraviolet (UV) light. Curing agent 500 can be cured at 190°C for 10 seconds.

[0096] According to Example 1, curing agent 500 can be cured at a pressure of 290 kPa. According to Example 2, curing agent 500 can be cured at a pressure of 310 kPa. According to Example 3, curing agent 500 can be cured at a pressure of 270 kPa.

[0097] When the curing agent 500 is cured under the conditions according to Example 1, the battery cell 1 (refer to Example 1) Figure 5 The insulation resistance defect rate can be 0.4%. When the curing agent 500 is cured under the conditions according to Example 2, the cell 1 (refer to Example 2) Figure 5 The insulation resistance defect rate of cell 1 (refer to Example 3) can be 1.11%. When the curing agent 500 is cured under the conditions according to Example 3, the insulation resistance defect rate of cell 1 (refer to Example 3) can be 1.11%. Figure 5 The insulation resistance failure rate can be 1.4%.

[0098] When the pressure applied to the curing agent 500 is 280 kPa to 300 kPa, cell 1 can be confirmed based on the insulation resistance failure rate (refer to...). Figure 5 The quality is excellent.

[0099] Figure 11 This is a flowchart illustrating a cell manufacturing method according to an embodiment of the present disclosure.

[0100] Reference Figures 1 to 11 The cell manufacturing method S10 may include a bag sealing step S100. In this step S100, the electrode assembly 20 may be accommodated in the receiving portion 200. In this step S100, the bag 10 may be folded.

[0101] In step S100, the first joints 410a, 420a and the second joints 410b, 420b can face each other. For example, the inner side 100i of the first joints 410a, 420a and the inner side 100i of the second joints 410b, 420b can face each other.

[0102] The first joints 410a and 420a may include or represent at least one of the first lead joint 410a and the first fold joint 420a. The second joints 410b and 420b may include or represent at least one of the second lead joint 410b and the second fold joint 420b.

[0103] For example, in step S100, the first lead joint 410a and the second lead joint 410b can face each other and engage. For example, in step S100, the first fold joint 420a and the second fold joint 420b can face each other and engage. Therefore, the bag 10 can be sealed.

[0104] The cell manufacturing method S10 may include a folded portion bonding step S200. In this step S200, the folded portion 420 may be folded and bonded by a curing agent 500.

[0105] Figure 12 This is a flowchart illustrating the bonding steps of the folded parts.

[0106] Reference Figures 1 to 12 The folding part bonding step S200 may include a first folding part folding step S210. In this step S210, the folding tail 422 can be bent and folded from the folding body 421. For example, in this step S210, at the boundary between the folding tail 422 and the folding body 421, the folding part 420 can be bent and folded toward the first receiving part 200a.

[0107] The folding part bonding step S200 may include a second folding of the folding part and a curing agent application step S220. In this step S220, the folded part 420 in the folded state may be bent toward the receiving part 200. For example, in this step S220, the folded part 420 may be bent in the folding direction of the folding part 420 and face the receiving part 200.

[0108] For example, in step S220, the folded portion 420 that folds toward the first receiving portion 200a can be bent toward the first receiving portion 200a and face the first receiving portion 200a.

[0109] For example, in step S220, the curing agent 500 can be applied between the folded portion 420 and the receiving portion 200 in the folded state. As another example, in step S220, after the curing agent 500 is applied to at least one of the folded portion 420 and the receiving portion 200 in the folded state, the folded portion 420 can be bent and face the receiving portion 200.

[0110] For example, in step S220, the folding body 421, the folding tail 422, the curing agent 500, and the receiving portion 200 can be arranged sequentially. For example, the folding tail 422 can be located between the folding body 421 and the curing agent 500.

[0111] The fold bonding step S200 may include a step S230 where the curing agent 500 is cured. In this step S230, the curing agent 500 may be irradiated with ultraviolet light (UV).

[0112] In step S230, at a temperature of 180°C to 230°C, a pressure of 280 kPa to 300 kPa can be applied to the curing agent 500 within 9 to 11 seconds. In step S230, the curing agent 500 cures, thereby fixing the folded portion 420 to the receiving portion 200 through the curing agent 500.

[0113] Figure 13 It shows the basis Figure 9 The diagram shows the state of the battery cell with the coating ratio of the curing agent shown.

[0114] Reference Figure 9 and Figure 13 The coating ratio of the curing part 500 or the width ratio of the curing part 500 can be the ratio of the width of the curing part 500 to the width of the folded tail 422, and can be expressed as a percentage.

[0115] According to Examples 4 to 8, curing agent 500 can be irradiated with ultraviolet light at a temperature of 190°C for 10 seconds. According to Examples 4 to 8, curing agent 500 can be cured under a pressure of 290 kPa.

[0116] The width of the curing section 500 can be represented by cell 1 (refer to...). Figure 6 The length of the cured portion 500 is based on the thickness direction of the folded portion 422. The width of the folded tail portion 422 can be expressed as the length of the folded tail portion 422 based on the direction in which the folded tail portion 422 extends from the folded body 421.

[0117] The width of the curing section 500 can be set based on the width of the folded tail section 422. For example, as shown in Embodiment 6, the width of the curing section 500 can be 100% of the width of the folded tail section 422.

[0118] For example, as shown in Example 4, the width of the curing portion 500 can be 60% of the width of the folded tail portion 422. In this case, the bonding force between the folded tail portion 422 and the receiving portion 200 is relatively low, so the insulation resistance failure rate may be relatively high at 1.2.

[0119] For example, as shown in Example 5, the width of the cured portion 500 can be 80% of the width of the folded tail portion 422. In this case, compared with the case where the width of the cured portion 500 is 60% of the width of the folded tail portion 422, the insulation resistance failure rate may be a relatively low 0.5.

[0120] For example, as shown in Example 8, the width of the cured portion 500 can be 140% of the width of the folded tail 422. A portion of the curing agent 500 forming the cured portion 500 may not be affected by ultraviolet light.

[0121] Uncured curing agent 500 may not effectively bond the fold 420 and the receiving portion 200. Additionally, uncured curing agent 500 may flow in its uncured state. When curing agent 500 flows, cell 1 (refer to...) Figure 6The quality may deteriorate. For example, according to Example 8, the insulation resistance defect rate of cell 1 is 0.6, which may be higher than that of Examples 6 and 7.

[0122] For example, as shown in Embodiment 7, the width of the cured portion 500 can be 120% of the width of the folded tail portion 422. In this case, the cured portion 500 may not flow, and the insulation resistance defect rate of the cell 1 is 0.4, which may be relatively low.

[0123] Therefore, when the width of the cured portion 500 is 80% to 120% of the width of the folded tail portion 422, the cured portion 500 effectively bonds the folded portion 420 and the receiving portion 200, and the insulation resistance failure rate can be relatively low. Furthermore, when the width of the cured portion 500 is 80% to 120% of the width of the folded tail portion 422, the curing agent 500 forming the cured portion 500 can prevent it from flowing.

[0124] The above description is merely an example of applying the principles of this disclosure, and other configurations may be included without departing from the scope of this disclosure.

Claims

1. A battery cell, comprising: Electrode assembly; The bag is formed from a bag sheet and includes a receiving portion for accommodating the electrode assembly; as well as hardener, The bag includes a folded portion, the folded portion comprising a first folded joint and a second folded joint formed of the bag sheet and facing each other and joined together. The fold includes: The folded body extends from the receiving portion; as well as The folded tail extends from the folding body and is folded to face the folding body. The folded body is bent such that the curing agent is located between the folded tail and the receiving portion.

2. The battery cell according to claim 1, wherein, The bag sheet forms the inner and outer sides of the bag. The inner side of the bag at the first folded joint is joined to the inner side of the bag at the second folded joint.

3. The battery cell according to claim 2, wherein, The bag sheet includes: Inner layer, forming the inner side of the bag; Outer layer, forming the outer side surface of the bag; and The intermediate layer is located between the inner layer and the outer layer. The inner layer, the middle layer, and the outer layer are stacked sequentially.

4. The battery cell according to any one of claims 1 to 3, wherein, The receiving portion includes a first receiving portion and a second receiving portion, which are formed from the bag sheet and extend along the length direction and are spaced apart from each other in the width direction. The bag includes a connecting portion formed of the bag sheet, which connects the first receiving portion and the second receiving portion and extends from the first receiving portion to the second receiving portion.

5. The battery cell according to claim 4, wherein, The first folded joint extends from the first receiving portion along the width direction. The second folded joint extends from the second receiving portion along the width direction.

6. The battery cell according to claim 5, wherein, The electrode assembly is located between the folded portion and the connecting portion.

7. The battery cell according to claim 6, wherein, The bag includes: A first lead wire junction portion, formed of the bag sheet, extends from the first receiving portion along the length direction; and The second lead joint is formed of the bag sheet, extends from the second receiving portion along the length direction, and is bonded to the first lead joint.

8. The battery cell according to claim 7, further comprising: Electrode leads extend from the electrode assembly along the length direction. The electrode lead is located between the first lead joint and the second lead joint.

9. A method for manufacturing a battery cell, comprising the following steps: The electrode assembly is housed in a receiving portion of a bag formed from a bag sheet, and the bag is folded so that a first fold joint and a second fold joint extending from the receiving portion are joined together, thereby sealing the bag; as well as The folded portion formed by joining the first folded joint and the second folded joint is bonded together using a curing agent.

10. The cell manufacturing method according to claim 9, wherein, The fold includes: The folding body extends from the receiving portion; and The folded tail extends from the folded body. The steps of bonding the folded portion include: The first folding step involves folding the tail section so that it faces the main body.

11. The cell manufacturing method according to claim 10, wherein, The steps of bonding the folded portion include: The second folding and curing agent application step involves bending the folded portion so that it faces the receiving portion, and placing the curing agent between the folded portion and the receiving portion.

12. The cell manufacturing method according to claim 11, wherein, The curing agent is located between the folded tail and the receiving portion.

13. The cell manufacturing method according to claim 11, wherein, The steps of bonding the folded portion include: The curing step cures the curing agent.

14. The cell manufacturing method according to any one of claims 11 to 13, wherein, The receiving portion includes a first receiving portion and a second receiving portion, the first receiving portion and the second receiving portion extending along the length direction and spaced apart in the width direction, respectively. The first folded joint extends from the first receiving portion along the width direction. The second folded joint extends from the second receiving portion along the width direction.

15. The cell manufacturing method according to claim 14, wherein, The bag further includes a connecting portion that connects the first receiving portion and the second receiving portion, and extends from the first receiving portion to the second receiving portion. The electrode assembly is located between the connecting portion and the folded portion.

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