Secondary battery production method and secondary battery
By attaching a pressing band to the folded end of the secondary battery and pressing it onto the outer surface of the battery casing, the problem of lithium deposition during fast charging is solved, thereby achieving battery stability and extended lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LG ENERGY SOLUTION LTD
- Filing Date
- 2021-09-16
- Publication Date
- 2026-05-19
AI Technical Summary
During the rapid charging process of secondary batteries, lithium deposition is prone to occur at the top of the battery, leading to problems with battery retention and swelling.
By attaching a pressing band to the folded end of the secondary battery and pressing it against the outer surface of the battery casing, the electrolyte trapped at the end is expelled, thus preventing lithium deposition.
It effectively prevents lithium deposition and reduces abnormal swelling and retention degradation during long-term cycling.
Smart Images
Figure CN116171499B_ABST
Abstract
Description
[0001] Cross-references to related applications
[0002] This application claims priority to Korean Patent Application No. 10-2020-0123363, filed on September 23, 2020, and Korean Patent Application No. 10-2021-0071815, filed on June 2, 2021, the entire contents of which are hereby incorporated by reference. Technical Field
[0003] This invention relates to a method for manufacturing secondary batteries and to secondary batteries themselves. Background Technology
[0004] Unlike primary batteries, secondary batteries are rechargeable and have a higher potential for smaller size and larger capacity. Therefore, much research is currently being conducted on secondary batteries. With technological advancements and increasing demand for mobile devices, the need for secondary batteries as an energy source is rapidly growing.
[0005] Rechargeable batteries are classified according to the shape of their casings into coin-shaped batteries, cylindrical batteries, prismatic batteries, and pouch batteries. In such secondary batteries, the electrode assembly installed in the battery casing is a rechargeable and dischargeable power generation device, which has a structure in which electrodes and separators are stacked.
[0006] In addition, electrode assemblies can be broadly classified as follows: wound electrode assemblies, in which a separator is inserted between the positive and negative electrodes, both of which are in the form of sheets coated with active materials, and then the positive electrode, separator, and negative electrode are wound together; stacked electrode assemblies, in which multiple positive and negative electrodes are stacked sequentially with a separator between them; and stacked / folded electrode assemblies, in which stacked cell cells are wound together with a long separator membrane.
[0007] Recently, pouch cells, which incorporate stacked / folded electrode assemblies in pouch cell housings made of aluminum laminates, have attracted much attention due to their low manufacturing cost, light weight, and easy shape deformation, and their usage is gradually increasing.
[0008] With the increasing demand for fast charging of pouch-type lithium batteries, batteries are increasingly being designed to have high energy density, long lifespan, and low swelling.
[0009] As fast charging speeds increase, lithium deposition occurs in the battery. Although lithium deposition initially occurs locally, it eventually leads to issues with battery retention and swelling degradation.
[0010] Regarding recent fast charging issues, there is a problem of lithium deposition at the top of the battery. To achieve both rapid charging and long lifespan, this deposition problem must be addressed. Specifically, the lamination at the top of the battery is weak, causing electrolyte retention and lithium deposition, which in turn leads to various problems.
[0011] [Prior Art Documents] (Patent Documents) Korean Patent Publication 10-2018-0051072 Summary of the Invention
[0012] Technical issues
[0013] One aspect of the present invention is to provide a secondary battery and a method for manufacturing the secondary battery, the method being able to prevent precipitation at the ends of the folded battery.
[0014] Technical solution
[0015] A method for manufacturing a secondary battery according to one embodiment of the present invention includes: a folding battery forming step for placing a cell battery on a surface of a separator to fold the cell battery sequentially to form a folding battery, each cell battery including at least one electrode and at least one separator; a tape attaching step for attaching a pressing tape to an end of the folding battery; a housing step for housing an electrolyte and the folding battery attached to the pressing tape in a battery housing; and a pressing step for pressing the outer surface of the battery housing to press the folding battery.
[0016] A secondary battery according to one embodiment of the present invention includes: a folding battery comprising a plurality of cell units and a separator membrane, each cell unit including at least one electrode and at least one separator membrane folded and arranged between the plurality of cell units; a pressing band attached to the folding battery; and a battery housing housing the folding battery and an electrolyte therein, wherein the pressing band is attached to an end of the folding battery so that the end of the folding battery is pressed when the outer surface of the battery housing is pressed.
[0017] Beneficial effects
[0018] According to the present invention, a pressing band can be attached to the end of the folding battery to apply pressing pressure to the end of the folding battery, thereby pushing the electrolyte retained at the end out of the cell, thus preventing precipitation and also preventing abnormal swelling and retention degradation during long-term cycling. Attached Figure Description
[0019] Figure 1 This is a plan view illustrating the folded battery forming process in a secondary battery manufacturing method according to an embodiment of the present invention.
[0020] Figure 2 This is a plan view of a unit cell in a secondary battery manufacturing method according to an embodiment of the present invention.
[0021] Figure 3This is a perspective view illustrating a first embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0022] Figure 4 This is a perspective view showing the containment process in a secondary battery manufacturing method according to an embodiment of the present invention.
[0023] Figure 5 This is a plan view showing the pressing process in a secondary battery manufacturing method according to an embodiment of the present invention.
[0024] Figure 6 This is a perspective view illustrating a second embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0025] Figure 7 This is a perspective view illustrating a third embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0026] Figure 8 This is a perspective view illustrating a fourth embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0027] Figure 9 This is a graph showing the performance of a secondary battery manufactured in a secondary battery manufacturing method according to an embodiment of the present invention and the performance of a secondary battery according to the prior art. Detailed Implementation
[0028] The objects, specific advantages, and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. It should be noted that components in the figures of this specification are represented by the same reference numerals wherever possible, even when shown in different figures. Furthermore, the present invention may be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. In the following description of the invention, detailed descriptions of prior art that may unnecessarily obscure the essential points of the invention will be omitted.
[0029] Method for manufacturing a secondary battery according to the embodiments
[0030] Figure 1 This is a plan view illustrating the folded battery forming process in a secondary battery manufacturing method according to an embodiment of the present invention. Figure 2 This is a plan view of a unit cell in a secondary battery manufacturing method according to an embodiment of the present invention, and Figure 3 This is a perspective view illustrating a first embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0031] also, Figure 4This is a perspective view showing the containment process in a secondary battery manufacturing method according to an embodiment of the present invention, and Figure 5 This is a plan view showing the pressing process in a secondary battery manufacturing method according to an embodiment of the present invention.
[0032] refer to Figures 1 to 5 According to one embodiment of the present invention, a method for manufacturing a secondary battery may include: a folding battery forming step of placing a unit battery 110 on a surface of a separator 120 to form a folding battery; a belt attaching step of attaching a pressing belt 300 to the folding battery 100; a housing step of housing the folding battery 100 and an electrolyte in a battery housing 200; and a pressing step of pressing the battery housing 200.
[0033] The following describes in more detail a method for manufacturing a secondary battery according to an embodiment of the present invention.
[0034] refer to Figure 1 and Figure 2 In the folding battery forming process, multiple cell units 110 can be placed on one surface of a separator 120 and then folded sequentially to form a folding battery 100, wherein each cell unit includes at least one electrode 113 and at least one separator 114. Here, the separator 120 can be folded to be arranged between the multiple cell units 110. Here, refer to... Figure 1 The separator 120 can be folded along the X-axis to form a folded battery 100.
[0035] The cell 110 is a rechargeable and dischargeable power generation element, and has a structure in which at least one electrode 113 and at least one separator 114 are arranged in an alternating stacked manner.
[0036] Electrode 113 may include a positive electrode 111 and a negative electrode 112. In addition, diaphragm 114 separates the positive electrode 111 and the negative electrode 112 from each other and provides electrical insulation.
[0037] The diaphragm 114 is made of insulating material, and the positive electrode 111, the diaphragm 114 and the negative electrode 112 are alternately laminated.
[0038] The diaphragm 114 may be, for example, a multilayer membrane made of microporous polyethylene, polypropylene, or a combination thereof, or a polymer membrane for solid polymer electrolytes or gel-type polymer electrolytes (e.g., polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride hexafluoropropylene copolymer).
[0039] The cell 110 may further include an electrode connector 130 disposed at the end of the electrode 113. Here, the electrode connector 130 may be disposed on the electrode 113. Here, the upper part of the electrode 113 may be the upper part of the folding cell 100 in a direction parallel to the folding axis of the folding cell 100. Here, refer to... Figure 1 The folding axis of the folding battery 100 can be in the Y-axis direction. In the secondary battery manufacturing method according to the present invention, the electrode connector 130 is not necessarily limited to being disposed on the upper part of the electrode 113. For example, the electrode connector 130 can also be disposed on each of the two parts (i.e., the upper and lower parts) of the electrode 113. The electrode connector 130 may include: a positive electrode connector 131 disposed on the end of the positive electrode 111; and a negative electrode connector 132 disposed on the end of the negative electrode 112. Here, for example, the positive electrode connector 131 can be disposed on the upper part of the positive electrode 111, and the negative electrode connector 132 can be disposed on the upper part of the negative electrode 112.
[0040] The folding battery 100 may further include an electrode lead 140, one side of which is connected to an electrode connector 130 and the other side protrudes to the outside of the battery housing 200 for connection to an external terminal.
[0041] Electrode leads 140 may include: a positive lead 141 connected to a positive terminal 131; and a negative lead connected to a negative terminal 132.
[0042] refer to Figure 3 In the attachment process, the pressing belt 300 can be attached to the end of the folding battery 100.
[0043] Furthermore, in the attachment process, as a first embodiment, the pressing band 300 can be attached to the end of the folding battery 100 where the electrode connector 130 is arranged. Here, as a first specific embodiment of the attachment process, the pressing band 300 can be attached to the upper part of the folding battery 100 where the electrode connector 130 is arranged. Here, in the attachment process, the pressing band 300 can be further attached to the lower part of the folding battery 100.
[0044] Furthermore, in the tape attachment process, the pressing tape 300 can be attached to the outermost surface of the separator membrane 120.
[0045] Here, in the attachment process, as a first embodiment, when the battery 100 to be folded is folded, the pressing band 300 can be attached to at least one of the front or rear surfaces of the folded battery 100 in a direction perpendicular to the folding axis. In this case, refer to Figure 3 The folding axis can be in the Y-axis direction, and the direction perpendicular to the folding axis can be in the Z-axis direction.
[0046] Here, the pressing band 300 can have a thickness t1 in the range of 10 μm to 300 μm. Therefore, since the thickness t1 of the pressing band 300 is formed to be 10 μm or more, when the outer surface of the battery casing 200 is pressed, a stronger pressing force is applied to the end of the folding battery 100 via the pressing band 300. Furthermore, since the pressing band 300 has a thickness of less than 300 μm, it does not occupy excessive space, and the separator disposed on the outer surface of the folding battery 100 will not be damaged by excessive pressing force.
[0047] Furthermore, the length L1 of the pressing band attached to the folding battery 100 in the folding axis direction of the folding battery 100 can be formed in the range of 5 mm to 300 mm. Therefore, when the length L1 of the pressing band 300 is formed to be 5 mm or more, and the outer surface of the battery casing 200 is pressed, the pressing force can be effectively applied to the end of the folding battery 100 that may be retained in the electrolyte via the pressing band 300. In addition, since the pressing band 300 is formed to be 300 mm or less, it does not occupy too much space, and the effect of preventing the electrolyte from being pushed out of the folding battery 100 at a distance from the part of the folding battery 100 that may be retained in the electrolyte is reduced.
[0048] Figure 6 This is a perspective view illustrating a second embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0049] refer to Figure 6 In the tape attachment process, as a second embodiment, the pressing band 300' can be attached to surround the upper part of the folding battery 100 so that the end of the folding battery 100 is pressed. Here, in the tape attachment process, as a specific second embodiment, the pressing band 300' can be attached to surround the upper part of the folding battery 100 so that the upper part of the folding battery 100 is pressed. Here, the pressing band 300' can be attached to surround the folding battery 100 in the folding direction of the folding battery 100. That is, the pressing band 300' can be attached to surround the upper part of the folding battery 100 in the full width direction of the folding battery 100. Therefore, it is possible to easily press the upper part of the folding battery 100 and maintain the pressing force.
[0050] Here, the tension of the pressing band 300' can be maintained so that the upper part of the folding battery 100 presses against the pressing band 300'. The thickness of the pressing band 300' can be in the range of 1 μm to 300 μm. Therefore, the thickness of the pressing band 300' is formed to be 1 μm or more, so that pressing force is applied to the end of the folding battery 100 via the pressing band 300', pressing the upper part of the folding battery 100 while simultaneously pressing around the upper part of the folding battery 100. Furthermore, since the pressing band 300' has a thickness of less than 300 μm, it does not occupy excessive space, and the separator arranged on the outer surface of the folding battery 100 will not be damaged due to excessive pressing force.
[0051] Furthermore, the length L2 of the pressing band attached to the folding battery 100 in the folding axis direction can be formed in the range of 0.5 mm to 300 mm. Therefore, the length L2 of the pressing band 300' is formed to be 0.5 mm or more, so that pressing force can be effectively applied to the end of the folding battery 100 that is retained in the electrolyte via the pressing band 300'. The pressing band surrounds the upper part of the folding battery 100 and presses the upper part of the folding battery 100, so that the upper part of the folding battery 100 is pressed. In addition, since the pressing band 300' has a thickness of less than 300 μm, it does not occupy too much space, and the separator arranged on the outer surface of the folding battery 100 will not be damaged due to excessive pressing force.
[0052] Figure 7 This is a perspective view illustrating a third embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0053] refer to Figure 7 In the attachment process, as a third specific embodiment, the pressing bands 300' and 300" can be attached to surround the upper and lower parts of the folding battery 100 so that the upper and lower parts of the folding battery 100 are pressed. Here, the pressing bands 300' and 300" can be attached to surround the folding battery 100 in the folding direction of the folding battery 100. That is, one pressing band 300' can be attached to the upper part of the folding battery 100 along its full width, and another pressing band 300″ can be attached to the lower part of the folding battery 100 along its full width. Therefore, the upper and lower parts of the folding battery 100 can be easily pressed and the pressing force can be maintained. Here, the thickness of each pressing band 300' and 300″ is 1μm to 300μm, and the lengths L2 and L3 of the pressing bands 300' and 300″ attached to the folding battery 100 in the direction of the folding axis of the folding battery 100 can be formed to be 0.5mm to 300mm.
[0054] Figure 8This is a perspective view illustrating a fourth embodiment of a secondary battery manufacturing method with an attachment process according to an embodiment of the present invention.
[0055] Additionally, refer to Figure 8 In the tape attachment process, as a fourth embodiment, the pressing tape 300"' can be attached around the upper part of the folding battery 100 so that the end of the folding battery 100 is pressed. Here, in the tape attachment process, as a fourth specific embodiment, the pressing tape 300"' can be attached around the upper part of the folding battery 100 so that the upper part of the folding battery 100 is pressed. Here, when folding the battery 100 to be folded, the pressing tape 300"' can be attached around the front and rear surfaces of the folding battery 100 in a direction perpendicular to the folding axis, and around the upper part of the folding battery 100 in the direction of the folding axis of the folding battery 100. That is, as a fourth embodiment, the pressing tape 300"' can include: a first part P2, which is attached to the front and rear surfaces of the folding battery 100 in a direction perpendicular to the folding axis of the folding battery 100; and a second part P1, which is attached around the upper part of the folding battery 100 in the direction of the folding axis of the folding battery 100. Therefore, the pressing band 300"' can be attached to the upper part of the folding battery 100 along its entire length, thereby preventing an increase in the full width of the folding battery 100, preventing unwinding of the folding battery 100, and suppressing excessive bulging. Furthermore, since the end of the electrode 113 is thinner than the central portion, separation of the electrode 113 from the separator 114 can be prevented. Here, the thickness of the pressing band 300"' can be in the range of 10μm to 300μm. Furthermore, the length L4 of the pressing band 300"' attached to the folding battery 100 in the direction of the folding axis of the folding battery 100 can be formed in the range of 5mm to 300mm. That is, the first portion P2 of the pressing band 300"' attached to the folding battery 100 can have a length of 5mm to 300mm.
[0056] refer to Figure 4 In the housing process, the electrolyte and the folding battery 100 with the pressing band 300 attached can be housed in the battery casing 200. Here, a housing portion 210 is formed inside the battery casing 200 to house the folding battery 100 and the electrolyte.
[0057] Furthermore, during the housing process, after the folded battery 100 and electrolyte are housed in the battery casing 200, the outer peripheral surface of the battery casing 200 can be sealed by heat fusion. Here, the upper and lower parts of the battery casing 200 can be joined together by applying heat and pressure along the outer edge of the housing portion 210 of the battery casing 200.
[0058] refer to Figure 5During the pressing process, the folded battery 100 can be pressed simultaneously with the outer surface of the battery casing 200.
[0059] During the pressing process, a pair of pressing clamps 30 can be used to press the two surfaces of the battery housing 200 on both sides.
[0060] The pair of pressing clamps 30 may include an upper clamp 10 and a lower clamp 20. Here, during the pressing process, the upper and lower sides of the battery casing 200 in which the folding battery 100 is housed can be pressed between the upper clamp 10 and the lower clamp 20.
[0061] Therefore, when the secondary battery E is pressed by the pressing clamp 30, the pressing band 300 attached to the upper part of the folding battery 100 can press the upper part of the folding battery 100 more forcefully, so as to easily push the electrolyte retained in the upper part of the folding battery 100 to the outside of the folding battery 100. Thus, precipitation can be prevented, and abnormal swelling and retention rate degradation during long-term cycling can be prevented.
[0062] Figure 9 This is a graph showing the performance of a secondary battery manufactured in a secondary battery manufacturing method according to an embodiment of the present invention and the performance of a secondary battery according to the prior art.
[0063] Figure 9 The diagrams shown illustrate the cycle performance of a secondary battery A according to the invention, in which a pressing band is attached to a folding battery, and the cycle performance of a secondary battery B according to the prior art, in which a pressing band is not attached to a folding battery.
[0064] refer to Figure 9 As shown in the graph, in secondary battery A manufactured by the manufacturing method for secondary batteries according to an embodiment of the present invention, the retention rate hardly changes with the progress of charge / discharge cycles, while in secondary battery B according to the prior art, a rapid retention rate decline occurs after 210 cycles with the progress of charge / discharge cycles.
[0065] Therefore, it can be seen that when a secondary battery A manufactured by a secondary battery manufacturing method according to an embodiment of the present invention is pressed by a pressing band attached to the upper part of the folding battery, the electrolyte can be pushed out, thereby preventing precipitation from the upper part of the folding battery.
[0066] Secondary battery according to the implementation method
[0067] The following will describe a secondary battery according to one embodiment of the present invention.
[0068] refer to Figures 1 to 5According to one embodiment of the present invention, a secondary battery E includes: a folding battery 100, which includes a plurality of cell cells 110 and a separator 120 folded and arranged between the plurality of cell cells 110; a pressing band 300 attached to the folding battery 100; and a battery housing 200 containing an electrolyte.
[0069] The secondary battery E according to one embodiment of the present invention relates to a secondary battery manufactured by the secondary battery manufacturing method according to the foregoing embodiments. Therefore, the content of this embodiment that is repeated in the content of the foregoing embodiments will be omitted or briefly described, and the differences between them will be mainly described.
[0070] In more detail, see reference Figure 1 and Figure 2 The folding battery 100 may include a cell 110 and a separator 120.
[0071] Each cell 110 may include at least one electrode 113 and at least one separator 114. The cell 110 may be a rechargeable and dischargeable power generation element and has a structure in which at least one electrode 113 and at least one separator 114 are arranged in an alternating stacked configuration.
[0072] Electrode 113 may include a positive electrode 111 and a negative electrode 112. In addition, diaphragm 114 separates the positive electrode 111 and the negative electrode 112 from each other and provides electrical insulation.
[0073] The separator 120 can be folded to be arranged between multiple cell units 110.
[0074] The cell 110 may further include an electrode connector 130 disposed at the end of the electrode 113. Here, the electrode connector 130 may be disposed on the electrode 113. Here, the upper part of the electrode 113 may be the upper part of the folding cell 100 in a direction parallel to the folding axis of the folding cell 100. Here, refer to... Figure 1 The folding axis of the folding battery 100 can be in the Y-axis direction. In the secondary battery according to the present invention, the electrode connector 130 is not necessarily limited to being disposed on the upper part of the electrode 113. For example, the electrode connector 130 can also be disposed on each of the two parts (i.e., the upper part and the lower part) of the electrode 113.
[0075] The electrode connector 130 may include a positive electrode connector 131 disposed at the end of the positive electrode; and a negative electrode connector 132 disposed at the end of the negative electrode. Here, for example, the positive electrode connector 131 may be disposed on the upper part of the positive electrode 111, and the negative electrode connector 132 may be disposed on the upper part of the negative electrode 112.
[0076] The folding battery 100 may further include an electrode lead 140, one side of which is connected to an electrode connector 130 and the other side protrudes to the outside of the battery housing 200 for connection to an external terminal.
[0077] Electrode leads 140 may include: a positive lead 141 connected to a positive terminal 131; and a negative lead connected to a negative terminal 132.
[0078] The battery casing 200 may include a receiving portion 210 in which the foldable battery 100 and electrolyte are housed. Here, the battery casing 200 may be provided as a pouch-type battery casing made of a flexible material. Here, the battery casing 200 may, for example, include an aluminum sheet and a resin layer disposed on each of the two surfaces of the aluminum sheet.
[0079] refer to Figure 3 The pressing band 300 can be attached to the folding battery 100. Here, the pressing band 300 can be attached to the end of the folding battery 100 so that the end of the folding battery 100 is pressed when the outer surface of the battery casing is pressed.
[0080] In addition, the pressing band 300 includes a heat dissipation material, so that when the electrode connector 130 arranged at the end of the folding battery 100 generates heat, the heat generated from the end of the folding battery 100 can be dissipated to prevent damage to the folding battery 100 including the separator.
[0081] Furthermore, the pressing band 300 may include a base material and an adhesive layer disposed on one surface of the base material. Here, the base material may be a polymer resin film. In this case, the base material may include, for example, any one of polypropylene, polyethylene, polyimide, and polyethylene terephthalate. In particular, polyimide and polyethylene terephthalate are materials with excellent heat dissipation properties.
[0082] In addition, the pressing band 300 can be attached to the outermost surface of the separator membrane 120.
[0083] Furthermore, the pressing band 300 can be attached to the end of the folding battery 100 where the electrode connector 130 is arranged. Here, as a first embodiment, the pressing band 300 can be attached to the upper part of the folding battery 100 where the electrode connector 130 is arranged. Here, the pressing band 300 can be further attached to the lower part of the folding battery 100.
[0084] More specifically, refer to Figure 3In a first embodiment, the pressing band 300 can be attached to at least one or more surfaces of the front or rear surface of the folding battery 100 in a direction perpendicular to the folding axis. Here, as a first specific embodiment, the pressing band 300 can be attached to both the front and rear surfaces of the folding battery 100 in a direction perpendicular to the folding axis. In this case, refer to... Figure 3 The folding axis can be oriented along the Y-axis, and the direction perpendicular to the folding axis can be oriented along the Z-axis. Here, the pressing band 300 can have a thickness t1 ranging from 10 μm to 300 μm. Therefore, since the thickness t1 of the pressing band 300 is formed to be 10 μm or more, a stronger pressing force is applied to the end of the folding battery 100 via the pressing band 300 when the outer surface of the battery casing 200 is pressed. Furthermore, since the pressing band 300 has a thickness of less than 300 μm, it does not occupy excessive space, and the separator arranged on the outer surface of the folding battery 100 will not be damaged by excessive pressing force.
[0085] Furthermore, the length L1 of the pressing band attached to the folding battery 100 in the direction of the folding axis can be formed in the range of 5 mm to 300 mm. Therefore, when the length L1 of the pressing band 300 is formed to be 5 mm or more and the outer surface of the battery casing 200 is pressed, the pressing force can be effectively applied to the end of the folding battery 100 that may be retained in the electrolyte via the pressing band 300. In addition, since the pressing band 300 is formed to be 300 mm or less, it does not occupy too much space, and the effect of preventing the electrolyte from being pushed out of the folding battery 100 at a distance from the part of the folding battery 100 that may be retained in the electrolyte is reduced.
[0086] refer to Figure 6In a second embodiment, the pressing band 300' can be attached around the end of the folding battery 100 so that the upper part of the folding battery 100 is pressed. Here, in a second specific embodiment, the pressing band 300' can be attached around the upper part of the folding battery 100 so that the upper part of the folding battery 100 is pressed. Here, the pressing band 300' can be attached around the folding battery 100 in the folding direction. Here, tension can be maintained on the pressing band 300' so that the upper part of the folding battery 100 presses against the pressing band 300'. Here, the thickness of the pressing band 300' can be in the range of 1 μm to 300 μm. Therefore, the thickness of the pressing band 300' is formed to be 1 μm or more, so that pressing force is applied to the end of the folding battery 100 via the pressing band 300', pressing the upper part of the folding battery 100, and simultaneously pressing around the upper part of the folding battery 100. Furthermore, since the pressing band 300' has a thickness of less than 300 μm, it does not take up too much space, and the diaphragm arranged on the outer surface of the folding battery 100 will not be damaged due to excessive pressing pressure.
[0087] Furthermore, the length L2 of the pressing band attached to the folding battery 100 in the direction of the folding axis can be formed in the range of 0.5 mm to 300 mm. Therefore, the length L2 of the pressing band 300' is formed to be 0.5 mm or more, so that pressing force can be effectively applied to the end of the folding battery 100 that is retained in the electrolyte via the pressing band 300'. The pressing band surrounds the upper part of the folding battery 100 and presses the upper part of the folding battery 100, thereby pressing the upper part of the folding battery 100. In addition, since the pressing band 300' has a thickness of less than 300 μm, it does not occupy too much space, and the separator arranged on the outer surface of the folding battery 100 will not be damaged due to excessive pressing force.
[0088] In addition, refer to Figure 7 As a third embodiment, the pressing bands 300' and 300" can be attached to surround the upper part of the folding battery 100 so that the upper part of the folding battery 100 is pressed, and can also be attached to surround the lower part of the folding battery 100 so that the lower part of the folding battery 100 is pressed. Here, the pressing bands 300' and 300" can be attached to surround the front and rear surfaces of the folding battery 100 in a direction perpendicular to the folding axis of the folding battery 100, and to surround the upper and lower parts of the folding battery 100 in the direction of the folding axis of the folding battery 100. Here, the thickness of each pressing band 300' and 300" is 1μm to 300μm, and the lengths L2 and L3 of the pressing bands 300' and 300" attached to the folding battery 100 in the direction of the folding axis of the folding battery 100 can be formed to be 0.5mm to 300mm.
[0089] Additionally, refer to Figure 8 As a fourth embodiment, the pressing band 300"' can be attached to surround the upper part of the folding battery 100 so that the end of the folding battery 100 is pressed. Here, as a fourth specific embodiment, the pressing band 300"' can be attached to surround the upper part of the folding battery 100 so that the upper part of the folding battery 100 is pressed. Here, the pressing band 300"' can be attached to surround the front and rear surfaces of the folding battery 100 in a direction perpendicular to the folding axis, and to surround the upper part of the folding battery 100 in the direction of the folding axis of the folding battery 100. That is, as a fourth embodiment, the pressing band 300"' can include: a first portion P2, which is attached to the front and rear surfaces of the folding battery 100 in a direction perpendicular to the folding axis of the folding battery 100; and a second portion P1, which is attached to surround the upper part of the folding battery 100 in the direction of the folding axis of the folding battery 100. Here, the thickness of the pressing band 300"' can be in the range of 10μm to 300μm. Furthermore, the length L4 of the pressing band 300"' attached to the folding battery 100 in the direction of the folding axis can be in the range of 5mm to 300mm. That is, the first portion P2 of the pressing band 300"' attached to the folding battery 100 can have a length of 5mm to 300mm.
[0090] While the invention has been specifically shown and described with reference to exemplary embodiments thereof, it should be understood that the scope of the invention is not limited thereto. Those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
[0091] Furthermore, the scope of protection of this invention will be defined by the appended claims.
[0092] [Explanation of reference numerals in the attached figures]
[0093] 10: Upper clamp
[0094] 20: Lower clamp
[0095] 30: Pressing clamp
[0096] 100: Foldable Battery
[0097] 110: Single cell battery
[0098] 111: Positive electrode
[0099] 112: Negative electrode
[0100] 113: Electrode
[0101] 114: Diaphragm
[0102] 120: Separator membrane
[0103] 130: Electrode connector
[0104] 131: Positive terminal connector
[0105] 132: Negative terminal connector
[0106] 140: Electrode lead
[0107] 141: Positive lead
[0108] 142: Negative lead
[0109] 200: Battery casing
[0110] 210: Accommodation section 300, 300', 300", 300"': Pressing belt E: Secondary battery
Claims
1. A method for manufacturing a secondary battery, the method comprising: A folding battery forming process is used to place a cell on a surface of a separator to fold the cell sequentially, thereby forming a folding battery, wherein each cell includes at least one electrode and at least one separator. An attachment process is included, which is used to attach a pressing strip to the end of the folding battery, wherein the pressing strip is attached to the outermost surface of the separator membrane; A housing process for housing the electrolyte and the folding battery attached to the pressing band within a battery casing; and The pressing process is used to press the outer surface of the battery casing to press the end of the folding battery, thereby pushing out the electrolyte that is stuck at the end of the folding battery from the cell.
2. The method for manufacturing a secondary battery according to claim 1, wherein, The cell further includes an electrode connector disposed on the upper part of the electrode, and In the attachment process, the pressing band is attached to the upper part of the folding battery for arranging the electrode connectors.
3. The method for manufacturing a secondary battery according to claim 2, wherein, In the tape attachment process, the pressing tape is further attached to the lower part of the folding battery.
4. The method for manufacturing a secondary battery according to claim 2, wherein, In the attachment process, when the cell battery to be folded is folded, the pressing band is attached to one or more of the front and rear surfaces of the folded battery in a direction perpendicular to the folding axis.
5. The method for manufacturing a secondary battery according to claim 2, wherein, In the tape attachment process, the pressing tape is attached to surround the upper part of the folding battery in order to press the upper part of the folding battery.
6. The method for manufacturing a secondary battery according to claim 5, wherein, In the tape attachment process, the pressing tape is attached to surround the folding battery in the folding direction of the folding battery.
7. The method for manufacturing a secondary battery according to claim 5, wherein, In the tape attachment process, the pressing tape is attached to the upper part of the folding battery in the direction of the folding axis.
8. A secondary battery, the secondary battery comprising: A folded battery includes multiple cell units and a separator membrane, each cell unit including at least one electrode and at least one separator membrane folded together and arranged between the multiple cell units; A pressing band, attached to the folded battery, wherein the pressing band is attached to the outermost surface of the separator membrane; and A battery casing that houses the folded battery and the electrolyte. The pressing band is attached to the end of the folding battery so that when the outer surface of the battery casing is pressed, the end of the folding battery is pressed, thereby pushing out the electrolyte retained at the end of the folding battery from the cell.
9. The secondary battery according to claim 8, wherein, The cell further includes an electrode connector disposed on the upper part of the electrode, and The pressing band is attached to the upper part of the folding battery for arranging the electrode connectors.
10. The secondary battery according to claim 9, wherein, The pressing band is further attached to the lower part of the folding battery.
11. The secondary battery according to claim 9, wherein, The pressing band is attached to one or more of the front and rear surfaces of the folding battery in a direction perpendicular to the folding axis of the folding battery.
12. The secondary battery according to claim 11, wherein, The thickness of the pressing band is from 10 μm to 300 μm.
13. The secondary battery according to claim 11, wherein, The pressing band attached to the folding battery has a length of 5 mm to 300 mm in the direction of the folding axis of the folding battery.
14. The secondary battery according to claim 9, wherein, The pressing band is attached to surround the upper part of the folding battery so that the upper part of the folding battery is pressed.
15. The secondary battery according to claim 14, wherein, The pressing band is attached to surround the folding battery in the folding direction.
16. The secondary battery according to claim 15, wherein, The thickness of the pressing band is from 1 μm to 300 μm.
17. The secondary battery according to claim 15, wherein, The pressing band attached to the folding battery has a length of 0.5 mm to 300 mm in the direction of the folding axis of the folding battery.
18. The secondary battery according to claim 14, wherein, The pressing band is attached to the upper part of the folding battery in the direction of the folding axis.
19. The secondary battery according to claim 8, wherein, The pressing band includes a base material and an adhesive layer, and The substrate material includes any one of polypropylene, polyethylene, polyimide, and polyethylene terephthalate.