Secondary battery and manufacturing method therefor

Abstract

The present invention relates to a secondary battery and a manufacturing method therefor. The secondary battery according to the present invention tapes and fixes, in a bent state, an electrode tab bonded to a bent electrode lead. A first taping unit is formed on the electrode tab at a portion where the electrode lead and the electrode tab are bonded, and a fixing taping unit fixes the bent electrode tab. In addition, the secondary battery according to the present invention may further comprise a second taping unit formed in a connection unit at a portion where the electrode tab and the connection unit are bonded. In the secondary battery, according to the present invention, the electrode tab is bent to reduce the size of the secondary battery, and the taping unit for fixing the bent electrode tab is attached to an electrode assembly so as to compensate for a thickness difference occurring at an end of the electrode assembly.

Description

Secondary battery and method of manufacturing the same

[0001] The present invention relates to a secondary battery and a method for manufacturing the same, and more specifically, to a secondary battery and a method for manufacturing the same in which the size can be reduced by fixing an electrode tab joined to an electrode lead having a bent shape by taping it in a bent state.

[0002] Recently, with the rapid increase in demand for portable electronic products and the full-scale development of electric vehicles, energy storage batteries, robots, and satellites, research on high-performance secondary batteries capable of repeated charging and discharging is actively underway.

[0003] Secondary batteries can be classified according to the shape of the battery case into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet. Can-type secondary batteries can be classified into cylindrical secondary batteries and prismatic secondary batteries depending on the shape of the metal can.

[0004] Figures 1a and 1b are diagrams illustrating a method of joining an electrode tab and an electrode lead in a conventional pouch-type secondary battery.

[0005] As illustrated in FIGS. 1a and 1b, a conventional pouch-type secondary battery (100) has an electrode tab (120) formed on one side of an electrode assembly (110). The electrode tab (120) is formed in a direction perpendicular to one side of the electrode assembly (110) by welding a non-existent tab of the electrode assembly (110). The electrode tab (120) is welded to a flat electrode lead (130). A battery case (140) encloses the electrode assembly (110) and the electrode tab (120) so that they are not exposed to the outside, and the end of the electrode lead (130) is exposed to the outside. The electrode lead (130) is provided with an insulating part (150) in the part that contacts the battery case (140) to provide insulation from the battery case (140).

[0006] In this structure, the secondary battery has a size equal to the length of the electrode tab (120) protruding from one side of the electrode assembly (110) and the length of the electrode lead. This results in a problem where the energy density of the secondary battery is reduced.

[0007] The objective of the present invention is to provide a secondary battery and a method for manufacturing the same that can reduce the size or increase the energy density by shortening the total length of the bonded electrode tab and electrode lead.

[0008] Another objective of the present invention is to provide a secondary battery and a method for manufacturing the same that can compensate for parts with thickness differences in an electrode assembly and reduce the risk of lithium precipitation.

[0009] A secondary battery according to an embodiment of the present invention may include an electrode assembly, an electrode tab, a first taping portion, and a fixing taping portion. The electrode assembly may comprise a plurality of unit electrode plates having a non-tab formed at one end and a separator located between each of the plurality of unit electrode plates. The electrode tab may be formed by joining at least a portion of the plurality of non-tabs on one surface of the electrode assembly. The electrode lead may have a connecting portion joined to the electrode tab and a leading portion bent with respect to the connecting portion. The first taping portion may be attached to the electrode tab among the portions joined to the electrode tab and the connecting portion. The fixing taping portion fixes the electrode tab in a state where the electrode tab is bent in a tab bending direction such that the end of the electrode tab approaches the electrode assembly and the end of the leading portion moves away from one surface of the electrode assembly.

[0010] A fixing taping portion of a secondary battery according to one embodiment of the present invention covers the entire connecting portion among the parts where the electrode tab and the connecting portion are joined, and can be formed with a length equal to the width of one side of the electrode assembly.

[0011] A fixed taping portion of a secondary battery according to one embodiment of the present invention can cover one side of an electrode assembly up to the position of a lead portion in the height direction of one side of the electrode assembly.

[0012] A fixed taping portion of a secondary battery according to one embodiment of the present invention may be formed up to a part of one side in the height direction of one side of an electrode assembly.

[0013] A first taping portion of a secondary battery according to one embodiment of the present invention may be formed to be longer than the width direction length of the electrode tab.

[0014] According to one embodiment of the present invention, the first taping portion of the secondary battery may have both ends folded to cover at least a portion of the connecting portion among the portions where the electrode tab and the connecting portion are joined. The outer surface of the portion covering at least a portion of the connecting portion of the first taping portion may be scratched.

[0015] A secondary battery according to one embodiment of the present invention may further include a second taping portion attached to the connecting portion among the portions where the electrode tab and the connecting portion are joined.

[0016] According to one embodiment of the present invention, the first taping part and the second taping part of the secondary battery are formed to be longer than the width direction length of the electrode tab so that they can be bonded to each other.

[0017] The first taping part and the second taping part of a secondary battery according to one embodiment of the present invention may have different lengths.

[0018] According to one embodiment of the present invention, the second taping portion of the secondary battery may have an outer surface that is not coated with adhesive treated with a scratch.

[0019] According to one embodiment of the present invention, the electrode tab of a secondary battery may be formed so as to be offset in the direction opposite to the direction in which the electrode tab bends from the center in the height direction of one surface of the electrode assembly.

[0020] In a secondary battery according to one embodiment of the present invention, when the electrode tab is bent, the lead portion of the electrode lead can be perpendicular to one surface of the electrode assembly at the center in the height direction of one surface of the electrode assembly.

[0021] In a secondary battery according to one embodiment of the present invention, a unit electrode plate of an electrode assembly may comprise a positive plate and a negative plate having a length longer than that of the positive plate and shorter than that of the separator. The electrode assembly may be formed by alternately stacking the positive plate and the negative plate such that the separator is positioned between them.

[0022] A fixed taping portion of a secondary battery according to one embodiment of the present invention may be formed up to a part of either the upper surface or the lower surface, which is a side surface in the height direction of one side of an electrode assembly. The length of the portion formed on either the upper surface or the lower surface of the electrode assembly may be greater than the difference in length between the separator and the positive plate.

[0023] According to one embodiment of the present invention, a positive plate of a secondary battery may have an inclined sliding portion formed at an end. The length of the portion where the fixed taping portion is formed on either the upper or lower surface of the electrode assembly may be greater than or equal to the sum of the length difference between the separator and the positive plate and the length of the sliding portion.

[0024] A secondary battery according to an embodiment of the present invention comprises an electrode assembly, an electrode tab, an electrode lead, a first taping portion, and a fixed taping portion. The electrode assembly is formed by laminating a plurality of positive plates having a non-bonding tab formed at one end, a plurality of negative plates having a non-bonding tab formed at the other end and being longer than the positive plates, and a separator that is longer than the negative plates and is located between each of the positive plates and negative plates. The electrode tab comprises a positive tab formed by joining the non-bonding tabs of a plurality of positive plates on one side of the electrode assembly, and a negative tab formed by joining the non-bonding tabs of a plurality of negative plates on the other side facing the one side of the electrode assembly. The electrode lead comprises a positive lead having a positive connection portion joined to the positive tab and a positive lead portion bent with respect to the positive connection portion, and a negative lead having a negative connection portion joined to the negative tab and a negative lead portion bent with respect to the negative connection portion. The first taping part comprises a first positive taping part attached to the positive tab among the parts where the positive tab and the positive connection part are joined, and a first negative taping part attached to the negative tab among the parts where the negative tab and the negative connection part are joined. The fixing taping part comprises a fixed positive taping part that fixes the positive tab in a bent state such that the end of the positive tab is close to the electrode assembly and the end of the positive lead part is far from one side of the electrode assembly, and a fixed negative taping part that fixes the negative tab in a bent state such that the end of the negative tab is close to the electrode assembly and the end of the negative lead part is far from the other side of the electrode assembly.

[0025] A secondary battery according to one embodiment of the present invention may further include a second taping portion. The second taping portion comprises a second positive taping portion attached to the positive connection portion among the portions where the positive tab and the positive connection portion are joined, and a second negative taping portion attached to the negative connection portion among the portions where the negative tab and the negative connection portion are joined.

[0026] A method for manufacturing a secondary battery according to an embodiment of the present invention comprises a preparation step, a tab formation step, a bonding step, a first taping part formation step, a bending step, and a fixed taping part formation step. In the preparation step, an electrode assembly is prepared having a plurality of unit electrode plates having a non-tab formed at one end and a separator located between each of the plurality of unit electrode plates. In the tab formation step, an electrode tab is formed by bonding at least a portion of the plurality of non-tabs on one side of the electrode assembly. In the bonding step, the electrode tab is bonded to the connecting portion of an electrode lead having a connecting portion and a lead portion bent relative to the connecting portion. In the first taping part formation step, an insulating tape is attached to the electrode tab in the portion where the electrode tab and the connecting portion are bonded to form a first taping part. In the bending step, the electrode tab is bent in a tab bending direction such that the end of the electrode tab approaches the electrode assembly and the end of the lead portion moves away from one side of the electrode assembly. In the fixed taping part formation step, an insulating tape is attached to the bent electrode tab to form a fixed taping part.

[0027] A method for manufacturing a secondary battery according to one embodiment of the present invention may further include a step of forming a second taping portion. In the step of forming the second taping portion, a tape is attached to the connection portion among the parts joined to one side of the electrode tab and the connection portion of the electrode lead portion to form the second taping portion.

[0028] The secondary battery according to the present invention can reduce the size of the secondary battery or increase energy density by joining an electrode lead with a bent shape and an electrode tab and bending the electrode tab.

[0029] In addition, the secondary battery according to the present invention can compensate for thickness differences occurring at the ends of the electrode assembly and reduce the risk of lithium precipitation by attaching a taping portion for fixing a bent electrode tab to the electrode assembly.

[0030] Figures 1a and 1b are diagrams showing a method of joining electrode tabs and electrode leads in a conventional pouch-type secondary battery.

[0031] FIG. 2 is a drawing showing a secondary battery in which electrode tabs are formed in both directions according to an embodiment of the present invention.

[0032] FIGS. 3a and FIGS. 3b are drawings showing an anode plate and a cathode plate according to an embodiment of the present invention.

[0033] FIG. 4 is a drawing showing an electrode lead according to one embodiment of the present invention.

[0034] FIG. 5 is a diagram showing the electrode tab and electrode lead of a secondary battery joined together according to one embodiment of the present invention.

[0035] FIG. 6 is a drawing showing that the electrode tab of a secondary battery according to one embodiment of the present invention is fixed by a fixing taping part in a bent state.

[0036] FIGS. 7a to 7c are drawings showing that a first taping part and a fixed taping part are attached to an electrode tab and an electrode lead in a secondary battery according to an embodiment of the present invention.

[0037] FIG. 8 is a drawing showing that a second taping portion is formed after the electrode tab and electrode lead of a secondary battery are joined according to another embodiment of the present invention.

[0038] FIG. 9 is a drawing showing that a fixing taping part fixes a second taping part while the electrode tab of a secondary battery is bent according to another embodiment of the present invention.

[0039] FIGS. 10a and FIGS. 10b are drawings showing that a first taping portion, a second taping portion, and a fixing taping portion are attached to an electrode tab and an electrode lead in a secondary battery according to another embodiment of the present invention.

[0040] FIG. 11 is a cross-sectional view showing a fixed taping portion attached to an electrode assembly according to one embodiment of the present invention.

[0041] FIGS. 12a and FIGS. 12b are drawings showing the electrode tab formation location and the lead-out location of the electrode lead when the electrode tab is bent, according to one embodiment of the present invention.

[0042] FIG. 13 is a drawing showing a secondary battery in which a positive electrode tab and a negative electrode tab are formed on one surface of an electrode assembly according to another embodiment of the present invention.

[0043] FIG. 14 is a drawing showing a method for manufacturing a secondary battery according to an embodiment of the present invention.

[0044] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0045] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this invention, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that in the accompanying drawings, identical components are indicated by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that may obscure the essence of the present invention will be omitted. For the same reason, some components in the accompanying drawings may be exaggerated, omitted, or schematically depicted.

[0047]

[0048] FIG. 2 is a drawing showing a secondary battery in which electrode tabs are formed in both directions according to an embodiment of the present invention, FIG. 3a and FIG. 3b are drawings showing a positive plate and a negative plate according to an embodiment of the present invention, FIG. 4 is a drawing showing an electrode lead according to an embodiment of the present invention, FIG. 5 is a drawing showing that the electrode tab and the electrode lead of a secondary battery according to an embodiment of the present invention are joined, and FIG. 6 is a drawing showing that the electrode tab of a secondary battery according to an embodiment of the present invention is fixed by a fixing taping part in a bent state.

[0049] As illustrated in FIGS. 2 to 6, a secondary battery (1000) according to an embodiment of the present invention may include an electrode assembly (1100), an electrode tab (1200), an electrode lead (1300), a first taping portion (1400), a fixed taping portion (1500), a battery case (1600), and an insulating portion (1700). The electrode assembly (1100) may have a plurality of unit electrode plates (1110) and a separator (1120). An active material may be applied to the unit electrode plates (1110). The plurality of unit electrode plates (1110) may include a positive electrode plate (1110a) on which an active material such as a transition metal oxide is applied to a metal plate such as aluminum, and a negative electrode plate (1110b) on which an active material such as graphite or carbon is applied to a metal plate such as copper or nickel. The separator (1120) is positioned between a plurality of unit electrode plates (1110) to prevent short circuits between the unit electrode plates (1110). The material of the separator (1120) may be polyethylene, polypropylene, or a composite thereof.

[0050] The electrode assembly (1100) can be formed by placing a separator (1120) between an anode plate (1110a) and a cathode plate (1110b) that are alternately arranged. That is, in one embodiment, the electrode assembly (1100) is formed by alternately stacking the anode plate (1110a), the separator (1120), the cathode plate (1110b), and the separator (1120). Accordingly, the electrode assembly (1100) can have a rectangular shape with a height (H) and a width (W). In another embodiment, the electrode assembly (1100) can be formed by arranging the anode plate (1110a), the separator (1120), and the cathode plate (1110b) in that order and then winding it.

[0051] As illustrated in FIGS. 3a and 3b, a plurality of unit electrode plates (1110) may have uncoated tabs (1111a, 1111b) formed thereon without an active material. In this embodiment, the positive plate (1110a) may have an uncoated tab (1111a) formed at one end, and the negative plate (1110b) may have an uncoated tab (1111b) formed at the other end opposite to the one end, but is not limited thereto. In one embodiment, the unit electrode plate (1110) and the uncoated tabs (1111a, 1111b) may be formed integrally by cutting a predetermined portion of a metal plate using a laser or the like to leave the unit electrode plate (1110) and the uncoated tabs (1111a, 1111b).

[0052] The non-removable tabs (1111a) of the positive plate (1110a) may overlap each other at a first position, and the non-removable tabs (1111b) of the negative plate (1110b) may overlap each other at a second position. In another embodiment, there may be two or more positions where the non-removable tabs (1111a, 1111b) overlap on each of the positive plate (1110a) and the negative plate (1110b). Multiple non-removable tabs (1111a, 1111b) overlapped at the same position may be connected to each other by ultrasonic welding, laser welding, etc., to facilitate the movement of current and form an electrode tab (1200).

[0053] The electrode tab (1200) formed by connecting the non-existent tab (1111a) of the positive plate (1110a) can be the positive tab, and the electrode tab (1200) formed by connecting the non-existent tab (1111b) of the negative plate (1110b) can be the negative tab. In this embodiment, the positive tab is formed in a direction perpendicular to one surface of the electrode assembly (1100), and the negative tab is formed in a direction perpendicular to the other surface of the electrode assembly (1100).

[0054] As illustrated in FIG. 4, the electrode lead (1300) may have a connecting portion (1310) and an extraction portion (1320). The connecting portion (1310) and the extraction portion (1320) may have the same width (Wc). Preferably, the length in the width (Wc) direction of the connecting portion (1310) and the length in the width (Wt) direction of the electrode tab (1200) may also be the same. The extraction portion (1320) is bent at a predetermined angle relative to the connecting portion (1310). In this embodiment, the angle at which the connecting portion (1310) and the extraction portion (1320) are bent is approximately 90 degrees. In this embodiment, the electrode lead (1300) may be an anode lead (1300a) and a cathode lead (1300b).

[0055] As illustrated in FIG. 5, the electrode lead (1300) can be joined to the electrode tab (1200). More specifically, the connecting portion (1310) of the electrode lead (1300) can be joined to the electrode tab (1200) by a method such as spot welding. In this embodiment, the electrode lead (1300) may be an anode lead joined to the anode tab (1200a) and a cathode lead joined to the cathode tab (1200b).

[0056] In this embodiment, the connecting portion (1310) of the electrode lead (1300) is joined to the lower side of the electrode tab (1200), but is not limited thereto and in other embodiments, the connecting portion (1310) may be joined to the upper side of the electrode tab (1200).

[0057] When joining the connecting part (1310) and the electrode tab (1200), it is preferable to align the end of the connecting part (1310) and the end of the electrode tab (1200). If the end of the connecting part (1310) and the end of the electrode tab (1200) do not align, a step difference may occur due to the connecting part (1310) and the electrode tab (1200), and the battery case (1600) may be damaged due to this step difference.

[0058] The first taping portion (1400) may be attached to one side of the electrode tab (1200) among the parts where the connection portion (1310) of the electrode tab (1200) and the electrode lead (1300) is joined. In this embodiment, the first taping portion (1400) may be a first positive taping portion attached to the joining portion of the positive tab (1200a) and the positive lead (1300a), and a first negative taping portion attached to the joining portion of the negative tab (1200b) and the negative lead (1300b).

[0059] The first taping portion (1400) is intended to protect the bonding portion and may be formed of an insulating tape. The material of the insulating tape forming the first taping portion (1400) may be an organic material having insulating and adhesive properties, and preferably may be cast polypropylene (CPP). An insulating tape made of cast polypropylene has excellent electrical insulation properties and good rigidity, so it is not damaged by protrusions that may occur at the bonding portion. In addition, an insulating tape made of cast polypropylene has the advantage of low reactivity with internal materials of the secondary battery (1000), such as electrolyte.

[0060] The fixed taping portion (1500) can fix the electrode tab (1200) when the electrode tab (1200) is bent in the tap bending direction (B). Here, the tap bending direction (B) is the direction in which the electrode tab (1200) is folded so that the end of the electrode tab (1200) is closer to the electrode assembly (1100) and the end of the lead portion (1320) of the electrode lead (1300) is further away from one side or the other side of the electrode assembly (1100). In this embodiment, the fixed taping portion (1500) may be an anode fixing taping portion that fixes the anode tab and a cathode fixing taping portion that fixes the cathode tab.

[0061] As the fixed taping portion (1500) fixes the electrode tab (1200), the electrode tab (1200), which is bent in the tap bending direction (B) as shown in FIG. 6, can maintain the bent state without returning to its original position. When the electrode tab (1200) is fixed in the bent state, the lead portion (1320) of the electrode lead (1300) protrudes in a direction perpendicular to one side or the other side of the electrode assembly (1100). Preferably, the lead portion (1320) is positioned in the center in the height (H) direction of one side or the other side of the electrode assembly (1100).

[0062] In one embodiment, the fixed taping portion (1500) may be formed of an insulating tape. The material of the insulating tape forming the fixed taping portion (1500) may be an organic material having insulating and adhesive properties, and preferably may be cast polypropylene (CPP) or polyethylene terephthalate (PET). Polyethylene terephthalate (PET) insulating tape has high heat resistance and electrical insulation properties, and is characterized by being cheaper than cast polypropylene (CPP) insulating tape.

[0063] In order to stably fix the electrode tab (1200), the fixing taping portion (1500) can cover the entire connecting portion (1310) facing outward when the electrode tab (1200) is bent, among the parts where the electrode tab (1200) and the connecting portion (1310) are joined. Additionally, the fixing taping portion (1500) is formed with a length equal to the width (W) of one side or the other side of the electrode assembly (1100), so that it can cover from one end to the other end in the direction of the width (W) of one side or the other side of the electrode assembly (1100). In another embodiment, the fixing taping portion (1500) may be formed to be longer than the width (W) of one side or the other side of the electrode assembly (1100).

[0064] When the fixed taping portion (1500) covers the connecting portion (1310), one end of the fixed taping portion (1500) comes into contact with the lead portion (1320) of the electrode lead (1300) that is bent relative to the connecting portion (1310) in the height (H) direction of one side or the other side of the electrode assembly (1100), and thus cannot be extended further. Therefore, the fixed taping portion (1500) covers one side or the other side of the electrode assembly (1100) in the height (H) direction up to the position of the lead portion (1320). In this embodiment, since the lead portion (1320) is located in the center in the height (H) direction of one side or the other side of the electrode assembly (1100), as shown in FIG. 6, the fixed taping portion (1500) also covers half of one side or the other side of the electrode assembly (1100) in the height (H) direction. In another embodiment, the height at which the fixed taping part (1500) covers one side or the other side of the electrode assembly (1100) may vary depending on the height of the extraction part (1320).

[0065] In this embodiment, the fixed taping portion (1500) may be formed up to a part of one side of the electrode assembly (1100) in the height (H) direction. For example, as shown in FIG. 6, when the fixed taping portion (1500) covers the upper half of the electrode assembly (1100) in the height (H) direction, the fixed taping portion (1500) is formed up to a part of the upper surface of the electrode assembly (1100), which is the side of the electrode assembly (1100) in the height (H) direction. In another embodiment, the fixed taping portion (1500) may cover the lower half of the electrode assembly (1100) in the height (H) direction, and the fixed taping portion (1500) may be formed up to a part of the lower surface of the electrode assembly (1100), which is the side of the electrode assembly (1100) in the height (H) direction. In this way, when the fixed taping portion (1500) is formed up to a part of one side of the electrode assembly (1100) in the height (H) direction, the fixed taping portion (1500) can stably fix the bent electrode tab (1200) and compensate for the thickness difference that occurs at the end of the electrode assembly (1100).

[0066] With the fixed taping portion (1500) fixed to the electrode tab (1200) bent in the tab bending direction (B), the electrode assembly (1100) can be accommodated in the battery case (1600). The battery case (1600) can be manufactured by molding a pouch film laminate. The pouch film laminate may include a substrate layer, a gas barrier layer, and a sealant layer. In the pouch film laminate, the substrate layer, the gas barrier layer, and the sealant layer may be laminated sequentially. The substrate layer is formed on the outermost layer of the pouch film laminate to protect the secondary battery (1000) from friction and collision with the outside. The substrate layer is made of a polymer and can electrically insulate the electrode assembly (1100) from the outside. The gas barrier layer is laminated between the substrate layer and the sealant layer to secure the mechanical strength of the pouch, block the entry and exit of gas or moisture from the outside of the secondary battery (1000), and prevent electrolyte leakage from inside the battery case (1600). The sealant layer is intended to completely seal the interior of the battery case (1600) by mutually thermally bonding at the sealing portion when the battery case (1600) is sealed. To this end, the sealant layer may be formed of a material having excellent thermal bonding strength.

[0067] As illustrated in FIG. 2, the battery case (1600) may include a first case (1610) and a second case (1620). A first receiving portion (1611) capable of accommodating an electrode assembly (1100) may be formed in the first case (1610). A second receiving portion (1621) capable of accommodating an electrode assembly (1100) may be formed in the second case (1620) while covering the first receiving portion (1611) from above so that the electrode assembly (1100) does not escape to the outside. The first case (1610) and the second case (1620) may be connected at one end to each other, but are not limited thereto and may be in various forms, such as being separated from each other and manufactured separately. In another embodiment, the second case (1620) may not have a second receiving portion (1621) formed therein, and the electrode assembly (1100) may be received in the first receiving portion (1611), and the second case (1620) may only serve to cover the first receiving portion (1611).

[0068] When the electrode assembly (1100), in which the electrode lead (1300) is joined to the electrode tab (1200), is housed in the battery case (1600), the lead portion (1320) of the electrode lead (1300) may be exposed to the outside of the battery case (1600). A portion of the lead portion (1320) protruding to the outside of the battery case (1600) may become a terminal portion and be electrically connected to an external terminal to supply electricity to the outside of the secondary battery (1000).

[0069] The insulating portion (1700) may be located at the portion where the lead portion (1320) of the electrode lead (1300) contacts the battery case (1600). The insulating portion (1700) prevents electricity generated from the electrode assembly (1100) from flowing to the battery case (1600) through the electrode lead (1300).

[0070] The insulating portion (1700) may be positioned to surround the outer surface of the lead portion (1320). Specifically, at least a portion of the lead portion (1320) may be surrounded by the insulating portion (1700). The insulating portion (1700) may be located in the sealing portion where the first case (1610) and the second case (1620) of the battery case (1600) are heat-fused.

[0071] When a bent electrode lead (1300) is joined to an electrode tab (1200) as in the secondary battery (1000) according to the present embodiment, and the electrode assembly (1000) is received in a battery case (1600) while the electrode tab (1200) is bent in the tab bending direction (B), the size of the secondary battery (1000) can be reduced or the energy density can be increased at the same size.

[0072]

[0073] FIGS. 7a to 7c are drawings showing that a first taping part and a fixed taping part are attached to an electrode tab and an electrode lead in a secondary battery according to an embodiment of the present invention.

[0074] As illustrated in FIGS. 7a to 7c, a first taping portion (1400) of a secondary battery (1000) according to one embodiment of the present invention is attached to one side of the electrode tab (1200) among the parts where the connection portion (1310) of the electrode tab (1200) and the electrode lead (1300) are joined, thereby protecting the joined portion. In order for the first taping portion (1400) to protect the entire joined portion, it is preferable that the length (L1) of the first taping portion (1400) be formed to be equal to or longer than the length in the width (Wt) direction of the electrode tab (1200).

[0075] When the length (L1) of the first taping portion (1400) is the same as the length in the width (Wt) direction of the electrode tab (1200), as shown in FIG. 7a, the first taping portion (1400) and the fixed taping portion (1500) are not joined to each other. In this case, there is an advantage that the bending of the fixed taping portion (1500) is neatly processed, but there is a disadvantage that the first taping portion (1400) cannot be held if the adhesive force of the first taping portion (1400) weakens.

[0076] When the length (L1) of the first taping portion (1400) is longer than the length in the width (Wt) direction of the electrode tab (1200), as shown in FIG. 7b, the first taping portion (1400) may be formed to be longer than the electrode tab (1200) in both directions in the width (Wt) direction of the electrode tab (1200). Accordingly, the portion of the first taping portion (1400) that extends beyond the electrode tab (1200) is bonded to a part of the fixed taping portion (1500). As a result, the fixed taping portion (1500) also fixes the first taping portion (1400), thereby enabling stable protection of the portion where the electrode tab (1200) and the electrode lead (1300) are joined.

[0077] In another embodiment, as illustrated in FIG. 7c, if the length (L1) of the first taping portion (1400) is longer than the length in the width (Wt) direction of the electrode tab (1200), the portion of the first taping portion (1400) that extends beyond the width (Wt) of the electrode tab (1200) can be folded to cover the outer side of the connecting portion (1310). That is, the first taping portion (1400) has both ends folded to cover the connecting portion (1310) of the portion where the electrode tab (1200) and the connecting portion (1310) are joined. As a result, the portion where the electrode tab (1200) and the electrode lead (1300) are joined can be safely protected.

[0078] In this case, the fixed taping portion (1500) may be attached to the outer surface of the first taping portion (1400) where no adhesive is applied. When attached to the outer surface of the first taping portion (1400) where no adhesive is applied, the adhesive strength between the fixed taping portion (1500) and the first taping portion (1400) may decrease depending on the insulating tape material of the first taping portion (1400). To prevent the decrease in adhesive strength, the outer surface of the first taping portion (1400) covering the connecting portion (1310) may be scratched.

[0079] In another embodiment, the two ends of the first taping portion (1400) covering the outer side of the connecting portion (1310) may be spaced apart without touching each other. As a result, the connecting portion (1310) is exposed by a predetermined distance (d) between the two ends of the first taping portion (1400). Since the fixing taping portion (1500) is attached to the connecting portion (1310) at the exposed predetermined distance (d), the decrease in adhesive strength caused by the insulating tapes being attached to each other can be prevented.

[0080]

[0081] FIG. 8 is a drawing showing that a second taping portion is formed after the electrode tab and electrode lead of a secondary battery according to another embodiment of the present invention are joined, FIG. 9 is a drawing showing that a fixing taping portion fixes the second taping portion while the electrode tab of a secondary battery according to another embodiment of the present invention is bent, and FIG. 10a and FIG. 10b are drawings showing that a first taping portion, a second taping portion, and a fixing taping portion are attached to the electrode tab and the electrode lead in a secondary battery according to another embodiment of the present invention.

[0082] As illustrated in FIGS. 8 to 10b, a secondary battery (1000) according to another embodiment of the present invention may include an electrode assembly (1100), an electrode tab (1200), an electrode lead (1300), a first taping portion (1400), a fixing taping portion (1500), a battery case (1600), an insulating portion (1700), and a second taping portion (1800). Detailed descriptions of the same content as described in FIGS. 2 to 7 in this embodiment are omitted.

[0083] The second taping portion (1800) may be attached to the connecting portion (1310) among the portions where the connecting portion (1310) of the electrode tab (1200) and the electrode lead (1300) are joined. In this embodiment, the second taping portion (1800) may be a second positive taping portion attached to the joining portion of the positive tab and the positive lead, and a second negative taping portion attached to the joining portion of the negative tab and the negative lead.

[0084] The second taping portion (1800) may be formed of an insulating tape. The material of the insulating tape forming the second taping portion (1800) may be an organic material having insulating and adhesive properties, and preferably may be cast polypropylene (CPP).

[0085] The fixed taping portion (1500) may cover a portion of one or the other side of the connecting portion (1310), the second fixed taping portion (1800), and the electrode assembly (1100) in order to fix the electrode tab (1200). In this case, the fixed taping portion (1500) may be attached to the outer surface of the second taping portion (1800) where the adhesive is not applied. Accordingly, the adhesive strength between the fixed taping portion (1500) and the second taping portion (1800) may be reduced depending on the insulating tape material of the second taping portion (1800). To prevent the reduction in adhesive strength, the surface of the outer surface of the second taping portion (1800) where the adhesive is not applied may be scratched.

[0086] The length (L2) of the second taping portion (1800) is formed to be longer than the length in the width (Wt) direction of the electrode tab (1200), and preferably longer than the length (L1) of the first taping portion (1400). Accordingly, the second taping portion (1800) can be attached to one side or the other side of the electrode assembly (1100) while the electrode tab (1200) is bent in the tap bending direction (B). In addition, since the fixing taping portion (1500) fixes the electrode tab (1200) and the second taping portion (1800) together, it has the effect of fixing the electrode tab (1200) that is bent at a length longer than the width (Wt) of the electrode tab (1200). As a result, the bent electrode tab (1200) can be stably fixed.

[0087] In this embodiment, the length (L2) of the second taping portion (1800) may be shorter than the length in the width (W) direction of one side or the other side of the electrode assembly (1100). Therefore, the second taping portion (1800) may be attached only to one side or the other side of the electrode assembly (1100). In this case, the fixing taping portion (1500) can prevent the end of the insulating tape forming the second taping portion (1800) from easily falling off. In another embodiment, the second taping portion (1800) may be formed to be longer than the length in the width (W) direction of one side or the other side of the electrode assembly (1100), and may be attached to both sides in the width (W) direction of one side or the other side.

[0088] In this embodiment, as shown in FIG. 10a, the length (L1) of the first taping portion (1400) may be formed to be longer than the length in the width (Wt) direction of the electrode tab (1200). In this case, the first taping portion (1400) and the second taping portion (1800) may be joined together. Thus, since the second taping portion (1800) fixes the first taping portion (1400), the part where the electrode tab (1200) and the electrode lead (1300) are joined can be stably protected.

[0089] In another embodiment, as shown in FIG. 10b, the length (L1) of the first taping portion (1400) may be formed to be equal to the length in the width (Wt) direction of the electrode tab (1200). When the length (L1) of the first taping portion (1400) is equal to the length in the width (Wt) direction of the electrode tab (1200), the first taping portion (1400) and the second taping portion (1800) are not joined to each other. In this case, the bending of the fixed taping portion (1500) and the second taping portion (1800) is neatly processed.

[0090]

[0091] FIG. 11 is a cross-sectional view showing a fixed taping portion attached to an electrode assembly according to one embodiment of the present invention.

[0092] As illustrated in FIG. 11, a fixing taping portion (1500) according to one embodiment of the present invention may be formed on one side or the other side on which the electrode tab (1200) of the electrode assembly (1000) is formed, and may be formed up to either side in the height (H) direction of the one side or the other side. When the fixing taping portion (1500) is attached up to the upper or lower side, which is the side in the height (H) direction, the electrode tab (1200) can be fixed more stably than when it is attached only to one side or the other side.

[0093] In this embodiment, the electrode assembly (1100) is formed by alternately stacking a separator (1120), an anode plate (1110a), a separator (1120), a cathode plate (1110b), and a separator (1120). At this time, the cathode plate (1110b) has a longer length than the anode plate (1110a), and the separator (1120) has a longer length than the cathode plate (1110b). As a result, at the end of the electrode assembly (1100), a length difference (AC) between the cathode plate (1110b) and the anode plate (1110a) and a length difference (AS) between the cathode plate (1110b) and the separator (1120) occur.

[0094] Due to the difference in length between the unit electrode plate (1110) and the separator (1120), the electrode assembly (1100) has a void at its end. When the fixing taping part (1500) is attached to the upper or lower surface of the electrode assembly (1100), the unit electrode plate (1110) and the separator of the electrode assembly (1100) are closely bonded by pressing down on this void. To achieve this, the length of the portion where the fixing taping part (1500) is attached to the upper or lower surface of the electrode assembly (1100) may be greater than the difference in length (AC+AS) between the separator (1120) and the positive plate (1110a).

[0095] In this embodiment, the positive plate (1110a) and the negative plate (1110b) may have an inclined sliding portion formed at their ends for a certain length (S). Due to this sliding portion, there is a risk of lithium precipitation at the ends of the electrode assembly (1100). To prevent this, a fixed taping portion (1500) may be attached up to the sliding portion of the positive plate (1110a). That is, the length of the portion where the fixed taping portion (1500) is attached to the upper or lower surface of the electrode assembly (1100) may be greater than or equal to the sum of the length difference (AC+AS) between the separator (1120) and the positive plate (1110a) and the length (S) of the sliding portion of the positive plate (1110a) (AC+AS+S). When the fixed taping part (1500) is attached to a position corresponding to the sliding part of the positive plate (1110a), the fixed taping part (1500) presses the space between the positive plate (1110a) and the separator (1120) by pressing it against the sliding part.

[0096]

[0097] FIGS. 12a and FIGS. 12b are drawings showing the electrode tab formation location and the lead-out location of the electrode lead when the electrode tab is bent, according to one embodiment of the present invention.

[0098] As shown in FIG. 12a, the connection portion (1320) of the electrode tab (1200) and the electrode lead (1300) can be joined. In order to prevent damage to the electrode assembly (1100) due to heat generated during joining, the portion where the electrode tab (1200) and the connection portion (1320) are joined is formed at a safe distance (t) from the portion where the electrode tab (1200) is bent.

[0099] When the electrode tab (1200) is bent due to this safety distance (t), the position in the height (H) direction of the first or second surface where the electrode tab (1200) is formed and the position in the height (H) direction of the lead portion (1310) of the electrode lead (1300) may differ. Therefore, if the electrode tab (1200) is formed in the center in the height (H) direction, the lead portion (1310) cannot be located in the center in the height (H) direction after the electrode tab (1200) is bent.

[0100] In order to position the extraction portion (1310) in the center in the height (H) direction after the electrode tab (1200) is bent, as shown in FIG. 12a, the electrode tab (1200) can be formed further offset in the opposite direction to the direction in which the electrode tab (1200) is bent from the center in the height (H) direction. In this embodiment, the electrode tab (1200) is formed close to the lower surface of the electrode assembly (1100) in the height (H) direction (h1 > h2). Here, the height distance difference (h1-h2) of the electrode tab (1200) varies according to the safety distance (t). That is, the height distance difference (h1-h2) of the electrode tab (1200) is determined according to the safety distance (t).

[0101] In this way, when the electrode tab (1200) is formed close to the lower surface of the electrode assembly (1100) in the height (H) direction and then the electrode tab (1200) is bent toward the upper surface of the electrode assembly (1100), the extraction portion (1310) is positioned in the center in the height (H) direction, as shown in FIG. 12b. In another embodiment, if the extraction portion (1310) is to be positioned off-center in the height (H) direction, the height distance difference (h1-h2) of the electrode tab (1200) can be adjusted accordingly. In yet another embodiment, the positioning of the extraction portion (1310) in the height (H) direction can take into account both the height distance difference (h1-h2) of the electrode tab (1200) and the angle at which the electrode tab (1200) is bent.

[0102]

[0103] FIG. 13 is a drawing showing a secondary battery in which a positive electrode tab and a negative electrode tab are formed on one surface of an electrode assembly according to another embodiment of the present invention.

[0104] As illustrated in FIG. 13, a secondary battery (2000) according to an embodiment of the present invention may include an electrode assembly (2100), an electrode tab (2200), an electrode lead (2300), a first taping portion (2400), a fixing taping portion (2500), a battery case (2600), and an insulating portion (2700). Details identical to those described in FIG. 2 to FIG. 11 in this embodiment are omitted from detailed description.

[0105] In this embodiment, the electrode assembly (2100) can be laminated such that the non-existent tabs of the positive plate (2110a) and the negative plate (2110b) are located on one side of the electrode assembly (2100). The electrode tab (2200) formed by connecting the non-existent tabs of the positive plate (2110a) becomes the positive tab, and the electrode tab (2200) formed by connecting the non-existent tabs of the negative plate (2110b) becomes the negative tab.

[0106] The positive tab and the negative tab can each be joined to an electrode lead (2300) having a bent shape. More specifically, the electrode tab (2200) is joined to the connecting portion (2310) of the electrode lead (2300) by a method such as spot welding.

[0107] The first taping portion (2400) may be attached to one side of the electrode tab (2200) among the parts where the connection portion (2310) of the electrode tab (2200) and the electrode lead (2300) are joined. The fixing taping portion (2500) fixes the electrode tab (2200) when the electrode tab (2200) is bent in the tap bending direction. The fixing taping portion (2500) covers the entire connection portion (2310) facing outward when the electrode tab (2200) is bent, and covers from one end to the other end in the width (W) direction of one side or the other side of the electrode assembly (2100). Accordingly, the fixing taping portion (2500) fixes the positive electrode tab and the negative electrode tab simultaneously.

[0108] Additionally, one end in the width direction of the fixed taping portion (2500) may cover one side or the other side of the electrode assembly (2100) up to the position of the extraction portion (1320) in the height (H) direction. The other end in the width direction of the fixed taping portion (2500) may be formed up to a part of the upper or lower surface, which is the side in the height (H) direction of one side of the electrode assembly (1100). The length of the portion to which the fixed taping portion (2600) is attached to the upper or lower surface of the electrode assembly (2100) may be greater than the length difference between the separator (2120) and the positive plate (2110a). In another embodiment, the length of the portion to which the fixed taping portion (2600) is attached to the upper or lower surface of the electrode assembly (2100) may be greater than the sum of the length difference between the separator (2120) and the positive plate (2110a) and the length of the sliding portion of the positive plate (2110a).

[0109] The battery case (2600) may include a first case (2610) and a second case (2620). A receiving portion (2611) capable of accommodating an electrode assembly (2100) is formed in the first case (2610). The second case (2620) covers the receiving portion (2611) from above so that the electrode assembly (2100) does not escape to the outside. In this embodiment, the first case (2610) and the second case (2620) are connected to each other on one side, but are not limited thereto and may be separated from each other.

[0110] A secondary battery (2000) according to an embodiment of the present invention may further include a second taping portion. The second taping portion is attached to the connecting portion (2310) among the portions where the connecting portion (2310) of the electrode tab (2200) and the electrode lead (2300) are joined.

[0111]

[0112] FIG. 14 is a drawing showing a method for manufacturing a secondary battery according to an embodiment of the present invention.

[0113] As illustrated in FIG. 14, a method for manufacturing an interest battery according to an embodiment of the present invention may include a preparation step (S3100), a tab forming step (S3200), a bonding step (S3300), a first taping part forming step (S3400), a bending step (S3500), a fixed taping part forming step (S3600), and a casing step (S3700).

[0114] In the preparation step (S3100), an electrode assembly is prepared having a plurality of unit electrode plates, each having a non-border tab formed on one end, and a separator located between each of the plurality of unit electrode plates. The unit electrode plates may be positive plates and negative plates. In one embodiment, the non-border tabs of the positive plates and the non-border tabs of the negative plates may be stacked so that they are located on one side and the other side of the electrode assembly facing each other. In another embodiment, the non-border tabs of the positive plates and the non-border tabs of the negative plates may be stacked so that they are located on the same side of the electrode assembly.

[0115] In the tab formation step (S3200), at least a portion of the non-bonded tabs of the unit electrode plates is joined to form an electrode tab. When the non-bonded tab of the positive plate and the non-bonded tab of the negative plate are located on one side and the other side of the electrode assembly, respectively, the non-bonded tab of the positive plate is connected on one side to form a positive tab, and the non-bonded tab of the negative plate is connected on the other side to form a negative tab. When the non-bonded tab of the positive plate and the non-bonded tab of the negative plate are located on the same side of the electrode assembly, the positive tab and the negative tab are formed in the same direction on the same side.

[0116] In the joining step (S3300), the electrode tab and the electrode lead are joined. The electrode lead has a connecting portion and a lead portion bent relative to the connecting portion. The connecting portion of the electrode lead is joined to the electrode tab by a method such as spot welding.

[0117] In the first taping portion formation step (S3400), a tape is attached to one side of the electrode tab among the parts joined to the connection portion of the electrode lead and one side of the electrode tab to form a first taping portion. The first taping portion may be formed with an insulating tape made of cast polypropylene (CPP). The length of the first taping portion may be formed to be equal to or longer than the width direction length of the electrode tab.

[0118] In the bending step (S3500), the electrode tab is bent in the tap bending direction so that the lead portion of the electrode lead protrudes away from the electrode assembly. As a result, the lead portion of the electrode lead protrudes in a direction perpendicular to the surface of the electrode assembly where the positive tab and the negative tab are located.

[0119] In the step of forming the fixed taping part (S3600), a fixed taping part is formed so that the electrode tab is fixed while the electrode tab is bent in the tap bending direction. The fixed taping part may be formed with an insulating tape made of cast polypropylene (CPP) or polyethylene terephthalate (PET). By fixing the electrode tab with the fixed taping part, the electrode tab bent in the tap bending direction can maintain the bent state without returning to its original position, and the lead portion is positioned at the center in the height direction of one side or the other side of the electrode assembly.

[0120] The fixed taping portion covers the entire connecting portion facing outward when the electrode tab is bent, and can be formed to cover from one end to the other end in the width direction of one side or the other side of the electrode assembly. Additionally, one end in the width direction of the fixed taping portion covers one side or the other side of the electrode assembly up to the position of the pull-out portion (1320) in the height direction, and the other end can be formed up to a part of the upper or lower surface, which is the side in the height direction of one side of the electrode assembly.

[0121] The fixed taping portion may be formed such that the length of the portion attached to the upper or lower surface of the electrode assembly is greater than or equal to the length difference between the separator and the anode plate. In another embodiment, the fixed taping portion may be formed such that the length of the portion attached to the upper or lower surface of the electrode assembly is greater than or equal to the sum of the length difference between the separator and the anode plate and the length of the sliding portion of the anode plate, so that the fixed taping portion is attached up to a position corresponding to the sliding portion of the anode plate.

[0122] In the casing step (S3700), the electrode assembly formed up to the fixed taping portion is received in the battery case. In this case, a portion of the lead portion of the electrode lead is exposed to the outside of the battery case to become a terminal portion. To insulate the battery case from the lead portion, the lead portion may be provided with an insulating portion at the part where it contacts the battery case. In one embodiment, the insulating portion may be provided on the electrode lead before the electrode tab and the electrode lead are joined, and in another embodiment, the insulating portion may be formed on the electrode lead before the casing step (S3800). Once the electrode assembly is received in the battery case, the battery case is sealed.

[0123] A method for manufacturing an interest battery according to another embodiment of the present invention may further include a second taping portion forming step. It is preferable that the second taping portion forming step be performed after the first taping portion forming step.

[0124] In the step of forming the second taping portion, a tape is attached to the connection portion among the parts joined between one side of the electrode tab and the connection portion of the electrode lead portion to form the second taping portion. The second taping portion may be formed to be longer than the width direction length of the electrode tab, and preferably longer than the first taping portion.

[0125]

[0126] Although an embodiment of the present invention has been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention.

Claims

1. An electrode assembly comprising a plurality of unit electrode plates having a non-tab formed on one end, and a separator located between each of the plurality of unit electrode plates; An electrode tab formed by joining at least a portion of the plurality of unoccupied tabs on one surface of the electrode assembly; An electrode lead having a connecting portion joined to the electrode tab and a leading portion bent with respect to the connecting portion; A first taping portion attached to the electrode tab among the portions joined to the electrode tab and the connecting portion; and A secondary battery comprising: a fixing taping portion for fixing the electrode tab in a state where the electrode tab is bent in a tab bending direction such that the end of the electrode tab approaches the electrode assembly and the end of the lead portion moves away from one surface of the electrode assembly.

2. In Paragraph 1, A secondary battery characterized in that the above-mentioned fixed taping portion covers the entire connecting portion among the portions where the electrode tab and the connecting portion are joined, and is formed with a length equal to the width of one side of the electrode assembly.

3. In Paragraph 2, A secondary battery characterized in that the above-mentioned fixed taping portion covers one side of the electrode assembly in the height direction of one side of the electrode assembly up to the position of the lead portion.

4. In Paragraph 2, A secondary battery characterized in that the above-mentioned fixed taping portion is formed up to a part of one of the height-direction sides of one side of the electrode assembly.

5. In Paragraph 1, A secondary battery characterized in that the first taping portion is formed to be longer than the width direction length of the electrode tab.

6. In Paragraph 5, A secondary battery characterized in that the first taping portion has both ends folded to cover at least a portion of the connecting portion among the parts where the electrode tab and the connecting portion are joined.

7. In Paragraph 6, A secondary battery characterized in that the outer surface of the portion covering at least a part of the connection portion of the first taping portion is scratched.

8. In Paragraph 1, A secondary battery characterized by further including a second taping portion attached to the connection portion among the portions joined to the electrode tab and the connection portion.

9. In Paragraph 8, A secondary battery characterized in that the first taping portion and the second taping portion are formed to be longer than the width direction length of the electrode tab and are bonded to each other.

10. In Paragraph 8, A secondary battery characterized in that the first taping portion and the second taping portion have different lengths.

11. In Paragraph 8, A secondary battery characterized in that the second taping portion has an outer surface that is not coated with adhesive and is scratched.

12. In Paragraph 1, A secondary battery characterized in that the electrode tab is formed further offset from the center in the height direction of one side of the electrode assembly in the direction opposite to the direction in which the electrode tab is bent.

13. In Paragraph 1, A secondary battery characterized in that, when the electrode tab is bent, the lead portion of the electrode lead is perpendicular to the surface of the electrode assembly at the center in the height direction of the surface of the electrode assembly.

14. In Paragraph 1, The unit electrode plate of the above electrode assembly comprises an anode plate and a cathode plate having a length longer than that of the anode plate and shorter than that of the separator, and A secondary battery characterized in that the electrode assembly is formed by alternately stacking the electrodes such that the separator is positioned between the positive electrode plate and the negative electrode plate.

15. In Paragraph 14, The above-mentioned fixed taping portion is formed up to a part of either the upper or lower surface, which is the height-direction side of one surface of the electrode assembly, and A secondary battery characterized in that the length of the portion formed on either the upper or lower surface of the electrode assembly is greater than the difference in length between the separator and the positive plate.

16. In Paragraph 15, The above positive plate has an inclined sliding portion formed at its end, and A secondary battery characterized in that the length of the portion formed on either the upper or lower surface of the fixed taping portion of the electrode assembly is greater than or equal to the sum of the length difference between the separator and the positive plate and the length of the sliding portion.

17. An electrode assembly formed by stacking a plurality of positive plates having a non-blocking tab formed at one end, a plurality of negative plates having a non-blocking tab formed at the other end and being longer than the positive plates, and a separator longer than the negative plates and located between each of the positive plates and the negative plates; An electrode tab comprising an anode tab formed by joining the non-bonding tabs of the plurality of anode plates on one surface of the electrode assembly, and a cathode tab formed by joining the non-bonding tabs of the plurality of cathode plates on the other surface facing the one surface of the electrode assembly; An electrode lead having an anode lead having an anode connection portion joined to the anode tab and an anode lead portion bent with respect to the anode connection portion, and a cathode lead having a cathode connection portion joined to the cathode tab and a cathode lead portion bent with respect to the cathode connection portion; A first taping portion comprising a first positive taping portion attached to the positive tab among the portions joined to the positive tab and the positive connection portion, and a first negative taping portion attached to the negative tab among the portions joined to the negative tab and the negative connection portion; and A secondary battery comprising: a fixed positive taping part for fixing the positive tab in a bent state such that the end of the positive tab is close to the electrode assembly and the end of the positive lead is far from one surface of the electrode assembly; and a fixed negative taping part for fixing the negative tab in a bent state such that the end of the negative tab is close to the electrode assembly and the end of the negative lead is far from the other surface of the electrode assembly.

18. In Paragraph 17, A secondary battery further comprising a second taping portion having a second positive taping portion attached to the positive connection portion among the portions joined to the positive tab and the positive connection portion, and a second negative taping portion attached to the negative connection portion among the portions joined to the negative tab and the negative connection portion.

19. A preparation step for preparing an electrode assembly having a plurality of unit electrode plates having a non-tab formed on one end, and a separator located between each of the plurality of unit electrode plates; A tab forming step of forming an electrode tab by joining at least a portion of the plurality of unsecured tabs on one surface of the electrode assembly; A joining step of joining the connecting portion and the electrode tab of an electrode lead having a connecting portion and a pull portion bent with respect to the connecting portion; A first taping portion forming step of attaching an insulating tape to the electrode tab among the portions joined to the electrode tab and the connection portion; A bending step of bending the electrode tab in a tap bending direction such that the end of the electrode tab approaches the electrode assembly and the end of the lead portion moves away from one surface of the electrode assembly; and A method for manufacturing a secondary battery comprising: a step of forming a fixing taping portion by attaching insulating tape to fix the above-mentioned bent electrode tab.

20. In Paragraph 19, A method for manufacturing a secondary battery, characterized by further including a second taping portion forming step of attaching a tape to the connection portion among the portions joined to one side of the electrode tab and the connection portion of the electrode lead portion.

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