Battery cell, battery module, and method for manufacturing battery cell

Abstract

The present invention relates to a battery cell, a battery module, and a method for manufacturing a battery cell. Specifically, the battery cell may include a cell case having an accommodating space; an electrode assembly in which a plurality of electrode plates and separators are alternately stacked and accommodated in the accommodating space; electrode tabs extending outward from the electrode plates and electrically connecting the electrode plates to external terminals; a gel electrolyte accommodated in the accommodating space to cover the electrode tabs and prevent the electrode tabs from moving; and a liquid electrolyte accommodated in the accommodating space to surround the other side of the electrode assembly on which the electrode tabs are not formed.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0127743 filed on September 28, 2021 and Korean Patent Application No. 10-2022-0122860 filed on September 27, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery cell, a battery module, and a method for manufacturing a battery cell, and more particularly to a battery cell, a battery module, and a method for manufacturing a battery cell with improved durability without degrading battery performance. [Background technology]

[0003] Currently, commercialized secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Lithium secondary batteries have almost no memory effect compared to nickel-based secondary batteries and can be charged and discharged freely. In addition, lithium secondary batteries have attracted attention due to their advantages of a very low self-discharge rate and high energy density.

[0004] Lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative active materials, respectively, and are made up of a positive electrode plate in which a positive electrode active material and a negative electrode active material are applied to current collectors, a negative electrode plate, an electrode assembly in which a separator is interposed between the positive electrode plate and the negative electrode plate, an electrolyte, and an exterior material in which the electrode assembly and the electrolyte are hermetically sealed.

[0005] In addition, the lithium secondary battery can be classified into a can type secondary battery and a pouch type secondary battery according to the type of the exterior material. In a can type secondary battery, an electrode assembly is built into a metal can. In a pouch type secondary battery, an electrode assembly is built into a pouch made of a non-uniform soft polymer material, for example, an aluminum laminate sheet pouch.

[0006] Meanwhile, as lithium secondary batteries are now widely used not only in small devices such as portable electronic devices but also in medium- and large-sized devices such as automobiles and power storage devices, research is being conducted to increase the capacity and output of lithium secondary batteries. For such medium- and large-sized devices, pouch-type secondary battery cells, which allow easy stacking of multiple battery cells, are used.

[0007] Meanwhile, the metal foils used for the positive and negative current collectors have an electrode tab formed on at least one side thereof, the electrode tab having a bent shape during a welding process between electrode leads.

[0008] Since the electrode tab is very thin, its mechanical rigidity is relatively weak. When the folded shape of the electrode tab is repeatedly folded and unfolded minutely, the electrode tab may easily break due to an external impact. The electrode tab breakage causes the electric capacity of the connected electrode to be inactive, resulting in a phenomenon in which the charge and discharge performance of the secondary battery cell is reduced during use. In particular, in the case of a pouch-type secondary battery cell provided in an automobile pack, the battery cell is exposed to frequent vibrations and impacts, and thus the life of the battery cell is rapidly shortened. Furthermore, the current collector has recently been made thinner to increase the energy density of the battery cell, which also reduces the mechanical rigidity of the electrode tab, and breakage frequently occurs at the folded part of the electrode tab or at the connection part between the electrode tab and the electrode. Furthermore, as the battery cell becomes smaller in size, the width of the electrode tab becomes narrower and the length of the tab becomes shorter, which causes a problem that the electrode tab breaks more easily when the battery cell is subjected to an external impact.

[0009] Therefore, there is a need to develop a new pouch-type secondary battery cell structure that can prevent the electrode tabs from being broken when subjected to an external impact. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention provides a battery cell, a battery module, and a method for manufacturing a battery cell that have improved durability without compromising battery performance. [Means for solving the problem]

[0011] According to one embodiment of the present invention, a battery cell may include: a cell case having an accommodating space; an electrode assembly in which a plurality of electrode plates and separators are alternately stacked and accommodated in the accommodating space; electrode tabs extending outward from the electrode plates and electrically connecting the electrode plates to external terminals; a gel electrolyte accommodated in the accommodating space to cover the electrode tabs and prevent the electrode tabs from moving; and a liquid electrolyte accommodated in the accommodating space to surround the other side of the electrode assembly on which the electrode tabs are not formed.

[0012] In one embodiment, the gel electrolyte may be located only in the peripheral region of the electrode tab, and the liquid electrolyte may be contained in the remaining space of the containing space that is not filled with the gel electrolyte.

[0013] According to another embodiment of the present invention, a battery module may include at least one battery cell.

[0014] According to another embodiment of the present invention, a method for manufacturing a battery cell includes the steps of: preparing an electrode assembly including a plurality of electrode plates with electrode tabs formed on at least one side thereof and a separator interposed between the electrode plates; disposing the electrode assembly in an accommodating space of a pouch; injecting the hardenable electrolyte composition into the accommodating space of the pouch through an injection space of the pouch so as to cover the electrode tabs; changing the hardenable electrolyte composition into a gel electrolyte having a gel phase to prevent the electrode tabs from moving; and injecting a liquid electrolyte into the accommodating space so as to surround the other side of the electrode assembly on which the electrode tabs are not formed.

[0015] In yet another embodiment, the curable electrolyte composition may include a curable compound in an amount of 3 wt % to 30 wt %.

[0016] In still another embodiment, the method may further include, before the step of injecting the curable electrolyte composition, forming a blocking portion configured to block the curable electrolyte composition from moving from the storage space to the injection space.

[0017] In still another embodiment, the step of forming the blocking portion may include a step of forming the blocking portion to extend from an outer periphery of the pouch along a boundary between the receiving space and the injection space and to protrude further inward of the electrode assembly than one side end of the electrode assembly at which the electrode tab is located.

[0018] In still another embodiment, the step of forming the blocking portion may include a step of melt-joining a portion of the pouch between the injection space and the storage space, or forming the blocking portion by pressurizing a portion of the pouch between the storage space and the injection space.

[0019] In still another embodiment, the method may further include, before the step of changing the curable electrolyte composition into a gel electrolyte in a gel phase to prevent the electrode tabs from moving, pressing and fixing the pouch and the electrode assembly using a jig plate outside the pouch to fix the shape of the curable electrolyte composition.

[0020] The step of preventing the electrode tab from moving by changing the curable electrolyte composition into a gel electrolyte in a gel phase may be performed in a state where the pouch and the electrode assembly are pressurized and fixed.

[0021] In still other embodiments, injecting the hardenable electrolyte composition may include positioning the pouch and the electrode assembly such that the electrode tabs are located at the bottom of the electrode assembly, and using gravity to cause the hardenable electrolyte composition to cover the electrode tabs.

[0022] In yet another embodiment, the method may further include rotating the pouch so that the electrode tabs are located at the side of the electrode assembly prior to the step of injecting the liquid electrolyte. Effect of the Invention

[0023] The battery cell of the present invention accommodates a gel electrolyte in the area where the electrode tabs are formed and a liquid electrolyte in the area of ​​the electrode assembly where the electrode tabs are not formed, thereby preventing the electrode tabs from moving and reducing deformation of the electrode tabs when an external impact is applied to the battery cell. Therefore, when the battery cell of the present invention is installed in an automobile and applied, even if frequent impacts and vibrations that occur during travel are transmitted to the battery cell, the gel electrolyte in a semi-solid state can minimize the movement and deformation of the electrode tabs.

[0024] Furthermore, the battery cell of the present invention can prevent the electrode tabs from being broken due to frequent movement of the electrode tabs, which can cause the electrical charge and discharge of the electrodes to be inactivated.The battery cell of the present invention can minimize damage to the electrode tabs even when an external impact is applied by accommodating a gel polymer electrolyte, and can effectively improve cycle characteristics by lowering the internal resistance of the battery by using a liquid electrolyte in combination.

[0025] According to another embodiment of the present invention, the manufacturing method of the present invention further includes a step of forming a blocking portion inside the pouch before the step of injecting the curable electrolyte composition, thereby preventing the curable electrolyte composition injected into the accommodation space from moving from the accommodation space to the injection space before the curing step. In this way, the manufacturing method of the present invention can easily maintain the state in which the curable electrolyte composition is arranged to cover the electrode tabs until the curing step by the blocking portion, thereby greatly improving the manufacturing process. [Brief description of the drawings]

[0026] [Figure 1] FIG. 2 is a plan view showing a battery cell according to an embodiment of the present invention. [Diagram 2]1 is an exploded perspective view showing a pouch and an electrode assembly of a battery cell according to an embodiment of the present invention; [Diagram 3] 2 is an exploded perspective view showing a plurality of electrode plates and a separator according to an embodiment of the present invention; FIG. [Figure 4] 2 is a vertical cross-sectional view showing the interior of a battery cell according to an embodiment of the present invention; [Diagram 5] 1 is a plan view showing the interior of a battery cell according to an embodiment of the present invention; [Figure 6] FIG. 13 is a plan view showing the interior of a battery cell according to another embodiment of the present invention. [Figure 7] 13 is a front view illustrating a state after an electrode assembly is inserted into an accommodating space of a pouch, in a method for manufacturing a battery cell according to another embodiment of the present invention. FIG. [Figure 8] FIG. 11 is a front view illustrating the inside of a pouch in which a curable electrolyte composition is being injected into a storage space, in a method for manufacturing a battery cell according to another embodiment of the present invention. [Figure 9] FIG. 11 is a front view showing the inside of a pouch in which a curable electrolyte composition arranged around an electrode tab in an accommodating space is thermally cured, in a method for manufacturing a battery cell according to another embodiment of the present invention. [Figure 10] FIG. 11 is a front view showing the inside of a pouch in which a curable electrolyte composition arranged around an electrode tab in an accommodating space is cured with ultraviolet light in a method for manufacturing a battery cell according to another embodiment of the present invention. [Figure 11] 13 is a front view illustrating the inside of a pouch in which a gel electrolyte is contained around an electrode tab in an accommodation space, in a method for manufacturing a battery cell according to still another embodiment of the present invention. FIG. [Figure 12] 5A to 5C are side views illustrating states before and after a battery cell is fixed using a fixing jig during hardening of a curable electrolyte composition, in a method for manufacturing a battery cell according to another embodiment of the present invention. [Figure 13] 5A to 5C are side views illustrating states before and after a battery cell is fixed using a fixing jig during hardening of a curable electrolyte composition, in a method for manufacturing a battery cell according to another embodiment of the present invention. [Figure 14]11 is a perspective view illustrating a state in which a blocking member presses a portion between an accommodation space and an injection space of a pouch, in a method for manufacturing a battery cell according to still another embodiment of the present invention. FIG. [Figure 15] 11 is a perspective view illustrating a state in which a portion between an accommodation space and an injection space of a pouch is pressurized using a blocking member, in a method for manufacturing a battery cell according to still another embodiment of the present invention. FIG. [Figure 16] FIG. 11 is a perspective view illustrating the inside of a pouch in which liquid electrolyte is being injected into the accommodation space, in a method for manufacturing a battery cell according to another embodiment of the present invention. [Figure 17] FIG. 11 is a front view illustrating a state in which one side of the containing space of the pouch is further sealed, in a method for manufacturing a battery cell according to another embodiment of the present invention. [Figure 18] 13 is a front view illustrating a state in which an injection space of a pouch is removed, in a method for manufacturing a battery cell according to another embodiment of the present invention. FIG. [Figure 19] FIG. 4 is a front view illustrating a step of primarily injecting a curable electrolyte composition in a method for manufacturing a battery cell according to still another embodiment of the present invention. [Figure 20] FIG. 4 is a front view illustrating a step of primarily curing a curable electrolyte composition in a method for manufacturing a battery cell according to still another embodiment of the present invention. [Figure 21] FIG. 4 is a front view illustrating a step of secondly injecting a curable electrolyte composition in a method for manufacturing a battery cell according to still another embodiment of the present invention. [Figure 22] FIG. 4 is a front view illustrating a step of second curing a curable electrolyte composition in a method for manufacturing a battery cell according to still another embodiment of the present invention. [Diagram 23] 1 is a perspective view showing a battery module according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the present invention, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Furthermore, the following embodiments may be modified into several different forms, and the scope of the technical idea of ​​the present invention is not limited to the following embodiments. Rather, these embodiments are provided to make the present invention more complete and complete, and to fully convey the technical idea of ​​the present invention to those skilled in the art.

[0028] The technology described in the present invention is not intended to be limited to a particular embodiment, but should be understood to include various modifications, equivalents, and / or alternatives of the embodiments of the present invention.

[0029] In connection with the description of the drawings, like reference numbers may be used for like components.

[0030] In the present invention, expressions such as "have," "can have," "include," or "can include" refer to the presence of a given feature (e.g., a value, a function, an operation, or a component such as a part) and do not exclude the presence of additional features.

[0031] In the present invention, expressions such as "A or B," "at least one of A or / and B," or "one or more of A or / and B" may include all possible combinations of the items listed together. For example, "A or B," "at least one of A and B," or "at least one of A or B" may refer to any of the following: (1) at least one A, (2) at least one B, or (3) both at least one A and at least one B.

[0032] FIG. 1 is a plan view showing a battery cell 100 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing a pouch 114 and an electrode assembly 120 of the battery cell 100 according to an embodiment of the present invention. FIG. 3 is an exploded perspective view showing a separator 170 and an electrode 122 according to an embodiment of the present invention. FIG. 4 is a vertical cross-sectional view showing an internal state of the battery cell 100 according to an embodiment of the present invention. And FIG. 5 is a plan view showing an internal state of the battery cell 100 according to an embodiment of the present invention. For reference, the gel electrolyte 150 and the liquid electrolyte 160 are omitted in FIG. 2 for convenience of explanation. Also, FIG. 5 shows a state where the first cell sheet 114T is removed from the battery cell 100 of FIG. 1 for convenience of explanation.

[0033] 1, a battery cell 100 according to an embodiment of the present invention may include a cell case 110 that accommodates an electrode assembly (not shown) and an electrolyte, and electrode leads 130 including a positive electrode lead 130a connected to a positive electrode tab (not shown) and a negative electrode lead 130b connected to a negative electrode tab (not shown). In addition, the cell case 110 may have a sealing part 111 formed by heat sealing on an outer periphery.

[0034] 1 to 5, the cell case 110 may include an accommodating space 110p1 that accommodates the electrode assembly 120, the electrode tabs 121, the gel electrolyte 150, and the liquid electrolyte 160. The accommodating space 110p1 may be a portion that is deformed into a cup shape by pressing a portion of at least one of the two cell sheets 114T and 114P using a hot press at high temperature. The accommodating space 110p1 may be a portion P that is protruded outwardly from each of the cell sheets 114T and 114P.

[0035] The accommodating space 110p1 of the cell casing 110 may be large enough to accommodate all of the electrode plates 122, the separator 170, the gel electrolyte 150, and the liquid electrolyte 160. For example, as shown in FIG 2, the accommodating space 110p1 of the cell casing 110 may be formed by combining a portion P of the first cell sheet 114T that is protruded upward and a portion R of the second cell sheet 114P that is recessed downward.

[0036] Meanwhile, the cell case 110 may be a pouch-type case made of a flexible material. The cell case 110 may include a first cell sheet 114T covering an upper portion of the electrode assembly 120, and a second cell sheet 114P coupled to a portion of a lower surface of the first cell sheet 114T and covering a lower portion of the electrode assembly 120. Each of the first cell sheet 114T and the second cell sheet 114P may be a laminate sheet. Specifically, the laminate sheet may have a structure in which a thin metal film (e.g., an Al film) is laminated between a water-resistant polymer film (nylon) and a thermal adhesive polymer film (e.g., cast polypropylene). The structure of the laminate sheet and materials constituting each layer are widely known in the technical field to which the present invention belongs, and therefore a detailed description thereof will be omitted.

[0037] In order to seal the cell casing 110, a portion of each of the first cell sheet 114T and the second cell sheet 114P may be heat-sealed to each other. The heat-sealing method may include a step of pressing at least a portion of the outer periphery of each of the first cell sheet 114T and the second cell sheet 114P, which are facing each other in a stacked state, with a high-temperature tool (e.g., a hot press). At this time, the heat-sealing temperature may be 110° C. to 150° C. For example, as shown in FIG. 1, the cell casing 110 may have a sealing portion 111 heat-sealed to the outer periphery.

[0038] Also, as shown in FIG. 3, the electrode plates 122 may be at least one positive electrode 122p and at least one negative electrode 122n according to electrical polarity. The electrode plate 122 may include a current collector (not shown) and a mixture M1 of an electrode active material, a conductive material, and a binder coated on the current collector. The current collector may be an aluminum alloy foil or a copper alloy foil. For example, the positive electrode 122p may be formed by applying a mixture of a positive electrode active material, a conductive material, and a binder to a current collector made of an aluminum alloy material. The negative electrode 122n may be formed by applying a mixture M2 of a negative electrode active material, a conductive material, and a binder to a current collector made of a copper alloy material. A separator 170 may be interposed between the positive electrode 122p and the negative electrode 122n. The separator 170 may serve to block an internal short circuit between the positive electrode 122p and the negative electrode 122n and to impregnate the electrolyte. The separator 170 of the present invention may be made of any material commonly used in secondary batteries without any particular limitations. For example, the separator 170 may include at least one material selected from the group consisting of polyethylene and polypropylene. The positive electrode 122p, the separator 170, and the negative electrode 122n may be sequentially stacked to form the electrode assembly 120.

[0039] The electrode tab 121 shown in FIG. 2 may not be coated with a mixture of the electrode active material, conductive material, and binder. The electrode tab 121 may be a path through which electrons can move. The electrode tab 121 may be formed by cutting an uncoated portion that is not coated with the positive electrode active material, or may be formed separately by connecting another conductive member to the uncoated portion of the electrode plate 122 by ultrasonic welding or the like. For example, as shown in FIG. 3, the positive electrode 122p and the negative electrode 122n may each have an electrode tab 121 protruding from a first side 122n1. However, the present invention is not limited to this form. For example, the electrode tab 121 may be formed on at least one of a first side, a second side, a third side, and a fourth side in each of the front, back, left, and right directions of the electrode 122. 3, when the positive electrode 122p has a rectangular shape on a plane, the positive electrode tab 121a may be formed on any one or more of a first side 122p1, a second side 122p2, a third side 122p3, and a fourth side 122p4. And, when the negative electrode 122n has a rectangular shape on a plane, the negative electrode tab 121b may be formed on any one or more of a first side 122n1, a second side 122n2, a third side 122n3, and a fourth side 122n4.

[0040] As shown in FIG. 2, the battery cell 100 according to an embodiment of the present invention may further include an electrode lead 130 coupled to a portion of the electrode tab 121. The electrode lead 130 may be an electrically conductive metal. As shown in FIG. 2, the electrode lead 130 may include a positive electrode lead 130a coupled to a positive electrode tab 121a and a negative electrode lead 130b coupled to a negative electrode tab 121b. The electrode lead 130 may be coupled to one or more of the electrode tabs 121 in various ways, such as by welding. A portion of the electrode lead 130 may be disposed to be exposed to the outside of the cell case 110. That is, the electrode lead 130 serves as an electrode terminal of the battery cell 100. For example, the positive electrode lead 130a may serve as a positive electrode terminal of the battery cell 100, and the negative electrode lead 130b may serve as a negative electrode terminal of the battery cell 100. 4, the battery cell 100 may include an insulating film 140 configured to cover a portion of an outer surface of the electrode lead 130. The insulating film 140 may be configured to electrically insulate the cell casing 110 and the electrode lead 130 and to be heat-sealed to the cell casing 110.

[0041] Meanwhile, the gel electrolyte 150 shown in Figures 4 and 5 means an electrolyte having a gel phase. The gel electrolyte 150 may include a polymer that is hardened to such an extent that the electrolyte exhibits a gel phase. That is, the gel phase means that the electrolyte is semi-solid and has high viscosity, so that it maintains a constant shape without flowing in a steady state.

[0042] Also, the gel phase can be phenomenologically defined as a soft solid-like material containing one or more liquids. For example, the gel electrolyte 150 may be mostly liquid in weight ratio and partially solid. Specifically, the gel electrolyte 150 may be manufactured by curing a curable compound mixed in the liquid electrolyte 160 and changing the phase to a gel-state electrolyte. The curable compound may include a thermosetting compound (A) or an ultraviolet curing compound (B).

[0043] Specifically, as shown in FIG. 4 and FIG. 5, the gel electrolyte 150 is accommodated in the accommodation space 110p1 of the cell case 110 to cover the electrode tab 121. That is, the gel electrolyte 150 may be located on one side of the electrode assembly 120 where the electrode tab 121 is located in the accommodation space 110p1. The gel electrolyte 150 may be included in a form that covers the outer surface of the electrode tab so as to prevent the electrode tab 121 from moving when an external impact is applied. For example, as shown in FIG. 4, the gel electrolyte 150 may be located between the inner surface of the accommodation space 110p1 and the first side 120a of the electrode assembly 120 where the electrode tab 121 is located. In this case, the gel electrolyte 150 may cover the outer surfaces of the positive electrode tab 121a and the negative electrode tab 121b so as to prevent the positive electrode tab 121a and the negative electrode tab 121b from moving. However, the present invention is not necessarily limited to this form. For example, when the electrode tab 121 is located on any one or more of the first side 120a, the second side 120b, the third side 120c, and the fourth side 120d of the electrode assembly 120, the gel electrolyte 150 may be located on any one or more of the first side 120a, the second side 120b, the third side 120c, and the fourth side 120d of the electrode assembly 120 on which the electrode tab 121 is located. Also, the gel electrolyte 150 may be configured to cover an outer surface of the electrode tab 121. In particular, the gel electrolyte 150 may be configured to cover a joint portion between the electrode tab 121 and the electrode lead 130.

[0044] In addition, the gel electrolyte 150 may be partially disposed on the other side of the electrode assembly 120 where the electrode tabs 121 are not located. For example, the gel electrolyte 150 may be partially disposed on each of the second side 120b and the fourth side 120d of the electrode assembly 120 where the electrode tabs 121 are not located.

[0045] Therefore, according to this configuration of the present invention, when an external impact is applied to the battery cell 100, the gel electrolyte 150 covers the electrode tabs 121, and thus the gel electrolyte 150 can prevent the electrode tabs 121 from moving and reduce deformation, compared to the conventional battery cell in which the liquid electrolyte 160 covers the electrode tabs. As a result, in the case of the battery cell 100 mounted in an automobile, even if frequent impacts and vibrations occurring during travel are transmitted to the battery cell 100, the gel electrolyte 150 in a semi-solid state can minimize the movement and deformation of the electrode tabs 121.

[0046] Furthermore, the present invention can prevent disconnection of the connection portion between the electrode tab 121 and the electrode 122 or the bent portion of the electrode tab 121 due to frequent movement of the electrode tab 121, thereby preventing deactivation of electrical charge and discharge of the electrode 122 due to disconnection. Furthermore, the battery cell 100 of the present invention can effectively extend the life of the battery cell 100 by minimizing damage to the electrode tab 121 even when an external impact is applied.

[0047] Also, the liquid electrolyte 160 shown in Figs. 4 and 5 means an electrolyte in a liquid state. The battery cell 100 according to an embodiment of the present invention may perform charge and discharge by exchanging ions between the positive electrode 122p and the negative electrode 122n via the liquid electrolyte 160. The liquid electrolyte 160 may be located between the positive electrode 122p and the negative electrode 122n so that ions may move between the positive electrode 122p and the negative electrode 122n. Also, the liquid electrolyte 160 may be located on the surface and in the pores of the separator 170. When the battery cell 100 is a lithium secondary battery, the liquid electrolyte may be a non-aqueous electrolyte.

[0048] In addition, the liquid electrolyte 160 may be accommodated in the accommodation space 110p1 to surround at least one other side of the electrode assembly 120 where the electrode tab 121 is not positioned. When the electrode tab 121 is positioned on the first side 120a of the electrode assembly 120, the liquid electrolyte 160 may be positioned on one or more of the remaining second side 120b, third side 120c, and fourth side 120d of the electrode assembly 120. For example, as shown in FIG. 5, when the electrode tab 121 is positioned on the first side 120a of the electrode assembly 120, the liquid electrolyte 160 may be positioned to surround the remaining second side 120b, third side 120c, and fourth side 120d of the electrode assembly 120.

[0049] According to this configuration of the present invention, when the liquid electrolyte 160 located between the electrodes 122 is consumed during charging and discharging of the battery cell 100, the liquid electrolyte 160 located on the other side of at least one of the electrodes 122 on which the electrode tabs 121 are not formed moves between the electrodes 122, making it possible to replenish the liquid electrolyte 160. Therefore, even if the liquid electrolyte 160 between the electrodes 122 is consumed after multiple charging and discharging cycles of the battery cell 100, the reduction in the lifespan of the battery cell 100 can be minimized.

[0050] Meanwhile, in the battery cell 100 of the present invention, the gel electrolyte 150 is filled only in the first side 120a of the electrode assembly 120 where the electrode tab 121 is located, and the liquid electrolyte 160 is disposed on as many different sides as possible among the remaining second side 120b, third side 120c, and fourth side 120d of the electrode assembly 120 where the electrode tab 121 is not formed, thereby ensuring an amount of liquid electrolyte 160 that can be replenished in preparation for consumption of the liquid electrolyte 160. Therefore, compared to surrounding the entire periphery of the electrode assembly 120 with the gel electrolyte 150, it is possible to effectively prevent deterioration of the cycle characteristics of the battery cell 100.

[0051] Meanwhile, FIG. 6 is a plan view showing the interior of a battery cell 100 according to another embodiment of the present invention.

[0052] 6, in a battery cell 100 according to another embodiment of the present invention, compared to the battery cell 100 of FIG. 5, the gel electrolyte 150 is accommodated only in the peripheral region C of the electrode tab 121 so as to cover the electrode tab 121, and the remaining space of the accommodation space 110p1 filled with the gel electrolyte 150 may be filled with the liquid electrolyte 160.

[0053] In FIG. 6, the remaining configuration of the battery cell 100, except for the gel electrolyte 150, may be configured similarly to the configuration in FIG.

[0054] 5, in the battery cell 100 of FIG 6, the remaining space of the receiving space 110p1 located on one side of the electrode assembly 120 where the electrode tab 121 is located, excluding a peripheral region C adjacent to the electrode tab 121, may be filled with a liquid electrolyte 160. For example, the gel electrolyte 150 is hollow inside, and may be formed by injecting a curable electrolyte composition into a small frame surrounding the peripheral region C of the electrode tab 121, curing the curable electrolyte composition, and removing the small frame.

[0055] Therefore, in the battery cell 100 according to another embodiment of the present invention, the gel electrolyte 150 is formed only in the peripheral region C of the electrode tab 121, and the remaining accommodating space 110p1 is filled with the liquid electrolyte 160, thereby increasing the amount of liquid electrolyte 160 accommodated in the accommodating space 110p1 of the cell case 110. As a result, the battery cell 100 of the present invention has an advantage that even if the liquid electrolyte 160 is consumed in the electrode assembly 120 during charging and discharging, there is sufficient liquid electrolyte 160 in the accommodating space 110p1, thereby minimizing the reduction in the lifespan of the battery cell 100.

[0056] Fig. 7 is a front view showing a state after an electrode assembly is inserted into the storage space of a pouch 114 in a method for manufacturing a battery cell 100 according to another embodiment of the present invention. And Fig. 8 is a front view showing the inside of a pouch 114 in which a curable electrolyte composition 155 is injected into the storage space 110p1 in a method for manufacturing a battery cell 100 according to another embodiment of the present invention. For reference, in Fig. 8, the pouch 114 is shown transparently so that the inside of the pouch 114 can be seen from the outside for the purpose of illustrating the drawings.

[0057] 7 and 8 together with Fig. 4 and Fig. 5, the present invention may provide a method for manufacturing the battery cell 100. The method for manufacturing the battery cell 100 according to an embodiment of the present invention includes inserting an electrode assembly 120, injecting a curable electrolyte composition 155, curing the curable electrolyte composition 155, and injecting a liquid electrolyte 160. In one embodiment, the curable electrolyte composition 155 may be injected in a liquid state and then cured to cause a phase change to a gel electrolyte 150.

[0058] In one embodiment, the step of inserting the electrode assembly 120 includes a step of inserting the electrode assembly 120 including the electrodes 122, etc., with the electrode tabs 121 formed on at least one side, and the separator 170 interposed between the electrodes 122, etc., into the receiving space 110p1 of the pouch 114. Here, the pouch 114 can be said to be a configuration of a step before manufacturing the cell case 110 in which the receiving space 110p1 is completely sealed. The pouch 114 may be formed by bonding the outer peripheries of the first cell sheet 114T and the second cell sheet 114P to each other. The pouch 114 may have a receiving space 110p1 in which the electrode tabs 121, the electrode assembly 120, the curable electrolyte composition 155, and the liquid electrolyte 160 can be received.

[0059] For example, the electrode tab 121 may be located on the first side 120a of the electrode assembly 120. However, the present invention is not limited to this embodiment, and according to another embodiment of the manufacturing method in FIG. 19 to FIG. 21 described later, in the battery cell of the present invention, the electrode tab 121 may be located on each of the first side 120a and the third side 120c of the electrode assembly 120. In this case, the gel electrolyte 150 may be disposed on each of the first side 120a and the third side 120c of the electrode assembly 120 in the receiving space 110p1 of the pouch 114. In this case, the liquid electrolyte 160 may be disposed between the electrode 122 and the separator 170, between the electrodes 122, etc., and on the second side 120b and the fourth side 120d of the electrode assembly 120 in the receiving space 110p1.

[0060] 2, 5 and 7 again, after the insertion step of the electrode assembly 120, the outer peripheries of the first cell sheet 114T and the second cell sheet 114P may be heat sealed in a stacked state to form the pouch 114. For example, as shown in Fig. 7, the pouch 114 may have a sealing portion 111 formed on the outer periphery. The sealing portion 111 may be formed by heat sealing the first outer periphery 114a, the third outer periphery 114c, and the fourth outer periphery 114d of the first cell sheet 114T and the second cell sheet 114P, respectively, to each other.

[0061] 7, at least one outer periphery (corner), for example, the second outer periphery 114b of each of the first cell sheet 114T and the second cell sheet 114P may not be fused to each other. As a result, the second outer periphery 114b of each of the first cell sheet 114T and the second cell sheet 114P of the pouch 114 may be spaced apart from each other. In this manner, the pouch 114 may be configured such that the curable electrolyte composition 155 or the liquid electrolyte 160 can flow into the storage space 110p1 through the gap between the first outer periphery 114a of each of the first cell sheet 114T and the second cell sheet 114P that are not heat-fused.

[0062] 8 together with FIG. 3, the step of injecting the curable electrolyte composition 155 may include a step of injecting the curable electrolyte composition 155 including a curable compound into the space in the receiving space 110p1 where the electrode tab 121 is located. Here, the curable electrolyte composition may be a mixture of a curable compound in a liquid electrolyte. The curable compound may include a thermosetting compound (A) or an ultraviolet curable compound (B). The curable electrolyte composition 155 may be configured to be a liquid phase electrolyte before curing, and to change the liquid phase electrolyte into a gel phase electrolyte by curing the curable compound in a subsequent step.

[0063] In addition, the curable electrolyte composition 155 may be disposed in the receiving space 110p1 so as to cover the outer surfaces of the electrode tabs 121 or to fill the spaces between the electrode tabs 121 after injection.

[0064] Meanwhile, the liquid electrolyte, which is a main component constituting the curable electrolyte composition, is a non-aqueous organic solvent in which at least one lithium salt is dissolved, and a typical non-aqueous electrolyte used in the manufacture of a lithium secondary battery can be used.

[0065] Specifically, the lithium salt is LiPF6, LiCl, LiBr, LiI, LiBF4, LiClO4, LiB 10 Cl 10, LiAlCl4, LiAlO4, LiCF3SO3, LiCH3CO2, LiCF3CO2, LiAsF6, LiSbF6, LiCH3SO3, LiN(SO2CF3)2 (lithium bis(trifluoromethanesulfonyl)imide, LiTFSI), LiN(SO2F)2 (lithium bis(fluorosulfonyl)imide, LiFSI) and LiN(SO2CF2CF3)2 (lithium bisperfluoroethanesulfonimide, LiBETI), or a mixture of two or more selected from the group consisting of LiPF6, LiBF4, LiN(SO2CF3)2 and LiN(SO2F)2. The lithium salt may be appropriately changed within a range that is normally usable, but in order to obtain the optimum effect of forming a corrosion prevention coating on the electrode surface, the lithium salt may be contained in the liquid electrolyte at a concentration of 0.8 M to 3.0 M, specifically, at a concentration of 1.0 M to 3.0 M.

[0066] Representative examples of the non-aqueous organic solvent include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), vinylene carbonate (VC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethylsulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), and gamma butyrolactone (γ-butyrolactone). However, the salt and organic solvent of the liquid electrolyte 160 are not necessarily limited to the above-listed structures, and similar effects can be achieved by using known structures and their equivalents.

[0067] In addition, the liquid electrolyte may further contain other additives to further improve high-temperature output characteristics, high-temperature stability, overcharge prevention, and battery expansion suppression effect at high temperatures. Examples of such other additives include cyclic carbonate compounds such as vinylene carbonate (VC) or vinyl ethylene carbonate (VEC); halogen-substituted carbonate compounds such as fluoroethylene carbonate (FEC); sultone compounds such as 1,3-propane sultone (PS), 1,4-butane sultone, ethene sultone, 1,3-propene sultone (PRS), 1,4-butene sultone, or 1-methyl-1,3-propene sultone; sulfate compounds such as ethylene sulfate (Esa), trimethylene sulfate (TMS), or methyl trimethylene sulfate (MTMS); lithium sultone (LiS), ... The other additives may include at least one of phosphate-based or phosphite-based compounds such as lithium difluoro(bisoxalato)phosphate, lithium difluorophosphate, lithium tetrafluorooxalatophosphate, or tris(trimethylsilyl)phosphate; borate-based compounds such as tetraphenylborate, lithium oxalyldifluoroborate (LiODFB), or lithium bisoxalatoborate (LiB(C2O4)2, LiBOB); benzene-based compounds such as fluorobenzene; silane-based compounds such as tetravinylsilane, and lithium salt-based compounds such as LiPO2F2, LiSO3F, or LiBF4. The other additives may be included in an amount of about 0.01 to 30% by weight, specifically 0.01 to 15% by weight, based on the total weight of the liquid electrolyte.

[0068] In addition, the thermosetting compound (A), which is one of the curable compounds, is a compound capable of forming a crosslinking bond by a thermal polymerization reaction to gel the curable electrolyte composition 155. There are no particular limitations on the thermosetting compound as long as it is a thermosetting compound that is commonly used in the manufacture of gel electrolytes. Specifically, the thermosetting compound (A) may be at least one of a polymerizable monomer, an oligomer, and a copolymer that has a polymerizable functional group selected from the group consisting of a vinyl group, an epoxy group, an allyl group, and a (meth)acrylic group in which a polymerization reaction can occur within the structure and that can be changed into a gel phase by polymerization or crosslinking.

[0069] More specifically, representative examples of the polymerizable monomer include tetraethylene glycol diacrylate, polyethylene glycol diacrylate (molecular weight: 50 to 20,000), 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxylate tetraacrylate, and the like. tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, poly(ethylene glycol) diglycidylether, 1,5-hexadiene diepoxide, glycerol propoxylate triglycidyl ether, vinylcyclohexene dioxide, 1,2,7,8-diepoxyoctane (1,2,7,The glycidyl ether may include at least one of 8-diepoxyoctane, 4-vinylcyclohexene dioxide, butylglycidyl ether, diglycidyl 1,2-cyclohexanedicarboxylate, ethylene glycol diglycidyl ether, glycerol triglycidyl ether, and glycidyl methacrylate.

[0070] Representative examples of the copolymer include at least one of PVDF-HFP (polyvinylidene-co-hexafluoropropylene), allyl 1,1,2,2-tetrafluoroethyl ether (TFE)-(2,2,2-trifluoroethyl acrylate) copolymer, TFE-vinyl acetate copolymer, TFE-(2-vinyl-1,3-dioxolane) copolymer, TFE-vinyl methacrylate copolymer, TFE-acrylonitrile copolymer, TFE-vinyl acrylate copolymer, TFE-methyl acrylate copolymer, TFE-methyl methacrylate (MMA) copolymer, and TFE-2,2,2-trifluoroethyl acrylate (FA) copolymer.

[0071] Meanwhile, when a thermosetting compound (A) is used as the curable compound, a polymerization initiator may be further included to induce thermal curing.

[0072] The polymerization initiator may be decomposed by heat, for example at 30° C. to 100° C. in the battery, or at room temperature (5° C. to 30° C.) to form radicals, and the polymerizable monomer may react by free radical polymerization to form a gel electrolyte.

[0073] Representative examples of such polymerization initiators include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, t-butyl peroxy-2-ethyl-hexanoate, cumyl hydroperoxide, and hydrogen peroxide. Organic peroxides or hydroperoxides such as 2,2'-azobis(2-cyanobutane), 2,2'-azobis(methylbutyronitrile), 2,2'-azobis(iso-butyronitrile) (AIBN), or 2,2'-azobisdimethylvaleronitrile (AMVN) may also be used.

[0074] The polymerization initiator may be included in an amount of 0.01 to 20 parts by weight, specifically 0.1 to 10 parts by weight, based on 100 parts by weight of the thermosetting compound (A). When the polymerization initiator is included in the range of 0.01 to 20 parts by weight, the conversion rate of the curable compound can be increased to ensure the characteristics of a gel electrolyte, and free reaction can be prevented to improve the wetting property of the electrolyte to the electrode.

[0075] Also, the UV-curable compound (B), which is one of the curable compounds, may include a UV-curable acrylate monomer, which may be at least one selected from the group consisting of ODA (octyl / decyl acrylate), IDA (isodecyl acrylate), LA (lauryl acrylate), SA (stearyl acrylate), PEA (phenoxyethyl acrylate), MNPEOA (nonylphenol ethoxylate monoacrylate), tetrahydrofurfuryl acrylate, cyclohexyl acrylate, 4-butylcyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 4-HBA (4-hydroxybutyl acrylate), and phenoxyethyl acrylate.

[0076] When an ultraviolet-curable compound (B) is used as the curable compound, a photopolymerization initiator may be further included so as to induce photocuring of the curable compound.

[0077] The photopolymerization initiator may include at least one of ethyl benzoin ether, isopropyl benzoin ether, α-methyl benzoin ethyl ether, benzoin phenyl ether, α-acyl oxime ester, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, anthraquinone, 2-anthraquinone, 2-chloroanthraquinone, thioxanthone, isopropyl thioxanthone, chlorothioxanthone, benzophenone, benzyl benzoate, or benzoyl benzoate.

[0078] Meanwhile, the curable electrolyte composition 155 may include a curable compound in a content of 3 wt% to 30 wt% based on the total weight of the composition. When the content of the curable compound is less than 3 wt% based on the total weight of the curable electrolyte composition 155, the electrolyte composition is unlikely to form a gel phase even if the curable compound is cured. Also, when the content of the curable compound is more than 30 wt% based on the total weight of the gel electrolyte 150, the viscosity of the curable electrolyte composition 155 increases, and the flowability of the curable electrolyte composition 155 is poor in the step of injecting the curable electrolyte composition 155 into the battery cell 100. Therefore, it is not easy to move the curable electrolyte composition 155 to the receiving space 110p1 in which the electrode tab 121 is formed, and a part of the curable electrolyte composition 155 is likely to remain between the electrodes 122, etc. during the movement. The curable electrolyte composition 155 remaining between the electrodes 122, etc. has a higher ion conduction resistance than the liquid electrolyte 160, and may cause a negative effect on the performance of the battery cell 100 (for example, an increase in the internal resistance of the battery). In one embodiment, the content of the curable compound in the curable electrolyte composition 155 may be 5 wt% to 30 wt% based on the total weight of the curable electrolyte composition. In one embodiment, the content of the curable compound in the curable electrolyte composition 155 may be 5 wt% to 25 wt% based on the total weight of the curable electrolyte composition. Specifically, the content of the curable compound may be 8 wt% to 20 wt% based on the total weight of the curable electrolyte composition. More specifically, the content of the curable compound may be 13 wt% to 30 wt% based on the total weight of the curable electrolyte composition.

[0079] Meanwhile, referring to FIG. 8 again, according to the manufacturing method according to an embodiment of the present invention, the pouch 114 may have an injection space 110p2 formed therein. Here, the injection space 110p2 may be a space located on one side (upper side) of the receiving space 110p1 in which the electrodes 122, etc. are received, among the internal spaces formed between the first cell sheet 114T and the second cell sheet 114P. For example, a region from the open second outer peripheral portion 114b of the pouch 114 to the front of the receiving space 110p1 may be set as the injection space 110p2. The injection space 110p2 may be configured to be communicated with the receiving space 110p1. The injection space 110p2 may act as a passageway so that the curable electrolyte composition 155 or the liquid electrolyte 160 can move to the receiving space 110p1.

[0080] 9 is a front view showing the inside of pouch 114 in which curable electrolyte composition 155 is thermally cured in accommodation space 110p1 in a method for manufacturing a battery cell according to another embodiment of the present invention. For reference, in FIG. 9, for the purpose of illustrating the drawing, the pouch is shown transparently so that the inside of pouch 114 can be seen from the outside.

[0081] 9, after injecting the hardenable electrolyte composition 155 as in FIG. 8, the pouch 114 is rotated so that the electrode tabs 121 face downward. That is, the hardenable electrolyte composition 155 can be moved by gravity so that the hardenable electrolyte composition 155 covers the electrode tabs 121.

[0082] In one embodiment, the curing step may include a step of curing the curable electrolyte composition 155 disposed in the receiving space 110p1 to cover the electrode tab 121 into a gel phase. For example, as shown in FIG. 9, when the curable electrolyte composition 155 includes a thermosetting compound, the curable electrolyte composition 155 may be thermally cured by storing the curable electrolyte composition 155 in a thermostatic chamber set at a predetermined temperature for a predetermined time or more. When the thermosetting compound is heated to form crosslinks through a thermal polymerization reaction, the curable electrolyte composition 155 in a liquid state may be converted into a gel state. For example, when the pouch 114 is stored in a thermostatic chamber, the pouch 114 may be stored in a thermostatic chamber at 60 degrees Celsius for 5 to 24 hours to convert the curable electrolyte composition 155 into a gel state.

[0083] 10 is a front view showing the inside of a pouch 114 in which a curable electrolyte composition 155 contained in the containing space is cured by ultraviolet light in a method for manufacturing a battery cell 100 according to still another embodiment of the present invention. For reference, in FIG. 10, the pouch is shown transparent so that the inside of the pouch 114 can be seen from the outside for ease of explanation of the drawings.

[0084] 10, in a method for manufacturing a battery cell 100 according to another embodiment of the present invention, the curable electrolyte composition 155 may include an ultraviolet curable compound (not shown). In this case, the curable electrolyte composition 155 injected into the receiving space 110p1 may be cured with ultraviolet light. At this time, a curing ultraviolet light irradiation device (not shown) may be used to irradiate ultraviolet light U to photo-cure the ultraviolet curable compound.

[0085] When using an ultraviolet-curable compound, a separate storage space such as a thermostatic chamber for thermal curing is not required, compared to when using a thermosetting compound, so the electrode manufacturing process can be simplified, and the degree to which the electrode assembly 120 is heated during the curing process is small, so negative effects on the performance of the battery cell 100 can be reduced.

[0086] In another embodiment of the manufacturing method, the curable electrolyte composition may include a curable compound that can be crosslinked when exposed to radiation. For example, the curable compound may include polyacrylic acid. The curable electrolyte composition may be gelled by exposure to radiation. For example, the curable electrolyte composition may be crosslinked to a predetermined degree by irradiating gamma rays generated by an electron beam (E-BEAM) to crosslink polyacrylic acid, and then may be changed into the gel electrolyte.

[0087] Therefore, according to the above-mentioned configuration of the present invention, the curable electrolyte composition is crosslinked (cured) by radiation, which is an environmentally friendly method since no harmful catalyst is required unlike other general polymerization initiators, and the chemical reaction can be caused even in a solid state or at a low temperature. Moreover, the curing process can be performed in a short time, so energy consumption is low.

[0088] 7 to 9 again, in the manufacturing method according to an embodiment of the present invention, a step of forming a blocking portion 113 may be performed before or after, preferably before, the step of injecting the curable electrolyte composition 155. The blocking portion 113 may be configured to block the curable electrolyte composition 155 from moving from the receiving space 110p1 to the injection space 110p2. As shown in FIG. 9, when the pouch 114 is rotated and disposed at an angle of 90 degrees counterclockwise, that is, when the pouch 114 is rotated and disposed so that the electrode tab 121 faces downward, the curable electrolyte composition 155 moves to and is positioned in the receiving space 110p1 at the first side 120a of the electrode assembly 120. The blocking portion 113 may prevent the curable electrolyte composition 155 from moving from the receiving space 110p1 to the injection space 110p2. More specifically, the blocking portion 113 may be formed between the injection space 110p2 and the receiving space 110p1. The blocking portion 113 may be formed to block a space between the injection space 110p2 and the receiving space 110p1 of the pouch 114. For example, as shown in Fig. 8, the blocking portion 113 may have a shape that extends long from a first outer periphery 114a of the pouch 114 facing the electrode tab 121 toward a third outer periphery 114c.

[0089] Therefore, according to such a configuration of the present invention, the manufacturing method of the present invention can prevent the curable electrolyte composition 155 injected into the accommodation space 110p1 from moving from the accommodation space 110p1 to the injection space 110p2 before being cured by further including a step of forming the blocking portion 113 before or after the injection step of the curable electrolyte composition 155. As a result, the manufacturing method of the present invention can prevent the curable electrolyte composition 155 from being separated into the injection space 110p2 in the curing step, so that the blocking portion 113 can easily maintain the state in which the curable electrolyte composition 155 is arranged to cover the electrode tab 121 until the curing step of the curable electrolyte composition 155, and the manufacturing process can be greatly improved.

[0090] In addition, in the step of forming the blocking portion 113, the blocking portion 113 may be formed to extend from the outer periphery of the pouch 114 along the boundary between the receiving space 110p1 and the injection space 110p2. For example, as shown in Fig. 8, the blocking portion 113 may be formed in the pouch 114 extending from the first outer periphery 114a along the boundary between the receiving space 110p1 and the injection space 110p2. The blocking portion 113 may be formed to protrude further toward the third outer periphery 114c of the electrode assembly 120 than an end of the first side 120a of the electrode assembly 120, etc.

[0091] 11 is a front view showing the inside of a pouch 114 containing a hardened gel electrolyte 150 in a containing space 110p1 in a method for manufacturing a battery cell 100 according to still another embodiment of the present invention. For reference, in FIG. 11, the pouch 114 is shown transparently so that the inside of the pouch 114 can be seen from the outside for ease of explanation.

[0092] 11 together with FIG. 2, in a method for manufacturing a battery cell 100 according to an embodiment, a portion of the electrode assembly 120 may be impregnated with a gel electrolyte 150 formed by curing the curable electrolyte composition 155. For example, as shown in FIG. 11, a depth D of one side of the electrode assembly 120 on which the electrode tab 121 impregnated with the gel electrolyte is formed may be 10 mm or less. If the impregnation depth D of the electrode assembly 120 impregnated with the gel electrolyte 150 exceeds 10 mm, the gel electrolyte 150 has a higher ion conduction resistance than the liquid electrolyte 160, which may hinder the performance of the electrode 122 or the electrode assembly 120.

[0093] Therefore, according to the above-described configuration of the present invention, in the manufacturing method of the present invention, the step of forming the blocking portion 113 includes a step of forming the blocking portion 113 to protrude further toward the inside of the electrode assembly 120 than one side end of the electrode assembly 120 where the electrode tab 121 is located. The curable electrolyte composition 155 may contact the first side 120a of the electrode assembly 120 or may be sufficiently filled into the receiving space 110p1 to the extent of impregnating a part of the first side 120a as shown in FIG. 11. Thus, in the present invention, the curable electrolyte composition 155 received in the pouch 114 in which the blocking portion 113 is formed may be cured to form the gel electrolyte 150, and the one side end of the electrode assembly 120 where the electrode tab 121 is located may be supported and fixed by the gel electrolyte 150 so as not to move toward the first outer periphery 114a of the pouch 114. The battery cell 100 manufactured by the manufacturing method of the present invention can ultimately effectively reduce damage to the electrode assembly 120 accommodated in the accommodation space 110p1 due to external impact.

[0094] 2, 7 and 8, the step of forming the blocking part 113 may include a step of melt-joining a portion between the injection space 110p2 and the receiving space 110p1 of the pouch 114. That is, the blocking part 113 may be formed to block a portion of the space by joining a portion of the region between the injection space 110p2 and the receiving space 110p1 of the pouch 114. For example, in the step of forming the blocking part 113, the inner surfaces of the first cell sheet 114T and the second cell sheet 114P of the pouch 114 may be heat-sealed in a state of being in close contact with each other by hot pressing.

[0095] According to this configuration of the present invention, the manufacturing method of the present invention includes a step of melt-joining a portion between the injection space 110p2 and the storage space 110p1 of the pouch 114, so that the blocking portion 113 can be formed using the sealing device that was used to form the sealing portion 111 of the existing pouch 114 without a separate blocking member for blocking the injection space 110p2, thereby having the advantage of minimizing the cost of forming the blocking portion 113.

[0096] Fig. 12 is a side view showing a state before the battery cell is fixed using a fixing jig 210 during the curing of the curable electrolyte composition 155 in the method for manufacturing a battery cell according to another embodiment of the present invention. And Fig. 13 is a side view showing a state after the battery cell 100 is fixed using a fixing jig 210 during the curing of the curable electrolyte composition 155 in the method for manufacturing a battery cell according to another embodiment of the present invention. For convenience of explanation, electrode tabs and the like are not shown in Figs. 12 and 13.

[0097] 12 and 13 together with FIG. 4 and FIG. 9, when the curable electrolyte composition 155 is injected into the pouch 114, a portion of the receiving space 110p1 of the pouch 114 in which the curable electrolyte composition 155 is received may be deformed in a convex shape toward the outside due to the fluidity of the curable electrolyte composition 155. When the curable electrolyte composition 155 is cured in a form in which a portion of the receiving space 110p1 of the pouch 114 is deformed in a convex shape, it is difficult to ensure consistent quality of the product because the deformation shape is different for each product, and there is a risk of defects occurring because the appearance of the pouch 114 is not smooth. Therefore, the curing step of the manufacturing method of the present invention may include a step of pressurizing and fixing the pouch 114 during the curing of the curable electrolyte composition 155. At this time, both outer sides of the pouch 114 can be pressed and fixed using a fixing jig 210. Specifically, the fixing jig 210 may include a first jig plate 212 and a second jig plate 213. Each of the first jig plate 212 and the second jig plate 213 may have a size corresponding to or larger than one side of the pouch 114. That is, each of the first jig plate 212 and the second jig plate 213 may have a size capable of covering the pouch 114. The pouch 114 and the electrode assembly 120 accommodated inside the pouch 114 may be interposed between the first jig plate 212 and the second jig plate 213. A portion of the accommodation space 110p1 of the pouch 114, which is deformed into a convex shape, may be pressurized by the first jig plate 212 and the second jig plate 213.

[0098] Also, the fixing jig 210 may further include a base 211, a first support base 214, and a second support base 215. The first support base 214 and the second support base 215 may be located on both sides (Y-axis direction) of the pouch 114. The base 211 may be configured to be mounted on the ground so that the fixing jig 210 can be stably positioned on the ground. The base 211 may have a plate shape extending parallel to the ground. For example, as shown in FIG. 12, the first support base 214 may include a pillar portion 214a extending from the upper surface of the base 211 in the upward direction (Z-axis direction), and a connecting portion 214b extending horizontally from the pillar portion 214a and connected to a side portion of the first jig plate 212 in the positive direction of the Y-axis. In addition, the second support stand 215 may have a pillar portion 215a extending upward from the upper surface of the stand 211, and a connecting portion 215b extending horizontally from the pillar portion 215a and connected to the side of the second jig plate 213 in the negative direction of the Y axis.

[0099] Further, the first support 214 and the second support 215 may be configured to be movable in a direction toward each other on the support 211 or in a direction away from each other. For example, when the first support 214 and the second support 215 move toward each other, the first jig plate 212 and the second jig plate 213 connected to the first support 214 and the second support 215, respectively, may be moved toward each other. At this time, the pouch 114 and the electrode assembly 120 housed in the pouch 114 may be fixed by applying pressure to both outer sides of the pouch 114 located between the first jig plate 212 and the second jig plate 213. For example, when the curing of the curable electrolyte composition 155 is completed, the first support 214 and the second support 215 may be moved away from each other to release the fixed state of the pouch 114. 12, the pouch 114 may have a shape in which a portion of the receiving space 110p1 of the pouch 114 is protruded in a convex shape by the curable electrolyte composition 155. However, as shown in FIG 13, when the first support stand 214 and the second support stand 215 are moved toward the pouch 114, the pouch 114 is pressurized by the first jig plate 212 and the second jig plate 213, and the pressurization may guide the receiving space 110p1, which is protruded by the curable electrolyte composition 155, to be deformed into an inward shape.

[0100] Therefore, according to this configuration of the present invention, the curing step includes a step of pressurizing and fixing the pouch 114 while the curable electrolyte composition 155 is curing, so that the electrode assembly 120 accommodated inside the pouch 114 can be stably fixed, and the curable electrolyte composition 155 can be prevented from gelling in a state where a portion of the accommodation space 110p1 of the pouch 114 is deformed into an outwardly convex shape by the curable electrolyte composition 155. As a result, the present invention can effectively reduce the defective rate of the battery cell 100.

[0101] Fig. 14 is a perspective view showing a state where a blocking member 180 is applied with pressure to a portion between the receiving space 110p1 and the injection space 110p2 of the pouch 114 in a method for manufacturing a battery cell 100 according to still another embodiment of the present invention. And Fig. 15 is a perspective view showing a state where a portion between the receiving space 110p1 and the injection space 110p2 of the pouch 114 is applied with pressure using the blocking member 180 in a method for manufacturing a battery cell 100 according to still another embodiment of the present invention. For reference, in Figs. 14 and 15, the pouch 114 is shown transparently so that the inside of the pouch 114 can be seen from the outside for ease of explanation.

[0102] 14 and 15 together with FIG. 4, the step of forming the blocking portion 113 in the method of manufacturing a battery cell 100 according to another embodiment of the present invention may include a step of pressing a portion between the receiving space 110p1 and the injection space 110p2 of the pouch 114 to block the portion. In this case, the manufacturing method of the present invention may pressurize a portion between the receiving space 110p1 and the injection space 110p2 using a separate blocking member. Such a blocking member may temporarily form the blocking portion 113 in the pouch 114 so that the curable electrolyte composition 155 is not moved from the receiving space 110p1 to the injection space 110p2. For example, as shown in FIG. 15, the blocking portion 113 may be temporarily formed by pressing a portion between the receiving space 110p1 and the injection space 110p2 of the pouch 114 using a tongue member as a blocking member 180.

[0103] Meanwhile, a pin-shaped tongue member as shown in Fig. 14 may be used as the blocking member 180 for forming the blocking portion 113. For example, as shown in Fig. 15, a part between the containing space 110p1 and the injection space 110p2 of the pouch 114 is interposed between two fingers 181 of the tongue, and then the space between the two fingers 181 is narrowed to apply pressure to the part between the containing space 110p1 and the injection space 110p2, thereby forming the blocking portion 113.

[0104] Therefore, according to this configuration of the present invention, the manufacturing method of the present invention includes a step of pressurizing and blocking a portion between the storage space 110p1 and the injection space 110p2 of the pouch 114 in the step of forming the blocking portion 113, so that the blocking portion 113 can be easily formed without heat-sealing a portion of the pouch 114, thereby effectively improving manufacturing efficiency.

[0105] Meanwhile, referring to FIG. 8 and FIG. 9 together with FIG. 2, the manufacturing method according to another embodiment of the present invention may further include a step of rotating and arranging the pouch 114 so that the electrode tab 121 is located below the electrodes 122, etc., performed after the step of injecting the curable electrolyte composition 155. At this time, the pouch 114 may be arranged so that the relatively wide surfaces of the cell sheets 114T and 114P are placed in the front-back direction (Y-axis direction). That is, the pouch 114 may be arranged so that it stands upright in the up-down direction based on the ground. For example, as shown in FIG. 9, the pouch 114 may be rotated 90 degrees clockwise or counterclockwise based on the front view of the pouch 114 (viewed from the Y-axis direction) after the step of injecting the curable electrolyte composition 155, and the electrode tab 121 may be located below based on the electrode assembly 120. That is, the pouch 114 may be rotated so that the electrode tab 121 faces the direction of gravity after the step of injecting the curable electrolyte composition 155. At this time, the injected curable electrolyte composition 155 may be positioned at a lower part of the receiving space 110p1 where the electrode tab 121 was positioned due to gravity.

[0106] As shown in FIG. 8, in the step of injecting the curable electrolyte composition 155, the injected curable electrolyte composition 155 is dispersed in the receiving space 110p1 of the pouch 114. In the step of rotating the pouch 114, the pouch 114 is rotated so that the electrode tab 121 is located at the bottom, so that the curable electrolyte composition 155 can gather at the bottom of the receiving space 110p1 to cover the electrode tab 121.

[0107] Therefore, according to this configuration of the present invention, the manufacturing method of the present invention further includes a step of arranging the pouch 114 so that the electrode tab 121 is located at the lower part of the electrode assembly 120, which is performed after the step of injecting the curable electrolyte composition 155. This prevents the gel electrolyte 150 from being disposed at a position other than the intended position while the curable electrolyte composition 155 is well collected at the lower part of the receiving space 110p1 of the pouch 114 so as to cover the electrode tab 121, and effectively reduces the manufacturing defect rate of the battery cell 100. In other words, the amount of the curable electrolyte composition 155 collected at the first side 120a of the electrode assembly 120 is reduced, and the durability improvement effect of the electrode tab 121 may be reduced.

[0108] Furthermore, if the gel electrolyte 150 remains partially between the electrodes 122, the gel electrolyte 150 has a higher ion conduction resistance than the liquid electrolyte 160, and therefore the performance of the battery cell may be somewhat degraded compared to a battery cell using only the liquid electrolyte 160. However, the manufacturing method of the present invention can minimize the gel electrolyte 150 remaining in the electrode assembly 120, thereby preventing the occurrence of defects such as a decrease in durability or performance of the manufactured battery cell.

[0109] FIG. 16 is a perspective view showing the state inside pouch 114 in which liquid electrolyte 160 is being injected into accommodation space 110p1, in a method for manufacturing a battery cell according to another embodiment of the present invention.

[0110] Meanwhile, the liquid electrolyte may have the same or different composition as the liquid electrolyte used in producing the curable electrolyte composition.

[0111] 2, 4, 9, and 16 again, the method of manufacturing a battery cell according to an embodiment of the present invention may further include a step of positioning the electrode tab 121 in the X-axis direction of the electrode assembly 120 before the step of injecting the liquid electrolyte 160. At this time, the pouch 114 may be in a form that is upright in the vertical direction (Z-axis direction) based on the ground so that the receiving space 110p1 can be seen from the front. At this time, since the curable electrolyte composition 155 has already undergone a phase change to a gel phase to form the gel electrolyte 150, even when the pouch 114 is rotated and disposed so that the electrode tab 121 is positioned at the side (X-axis direction) of the electrode assembly 120, the gel electrolyte 150 may not move to another position in the receiving space 110p1. And, the liquid electrolyte 160 may be filled in the remaining space of the receiving space 110p1 where the gel electrolyte 150 is not positioned.

[0112] Specifically, the step of injecting the liquid electrolyte 160 may include injecting the liquid electrolyte 160 into the receiving space 110p1 through the injection space 110p2 via the open second outer periphery 114b of the first cell sheet 114T and the second cell sheet 114P. At this time, the liquid electrolyte 160 may be positioned between the electrodes 122, etc., and surrounding the other side of the electrodes 122, etc., where the electrode tabs 121 are not positioned. For example, the liquid electrolyte 160 may be positioned between the electrodes 122, etc., and at the outermost side of the electrodes 122, etc. Also, as shown in FIG. 16, the liquid electrolyte 160 may be positioned to surround the second side 120b, the third side 120c, and the fourth side 120d of the electrode assembly 120.

[0113] Therefore, according to this configuration of the present invention, when the liquid electrolyte 160 located between the electrodes 122, etc. is consumed during charging and discharging of the manufactured battery cell 100, the liquid electrolyte 160 located on the other side moves between the electrodes 122, etc. by the amount of consumed liquid electrolyte 160, thereby making it possible to replenish the liquid electrolyte 160. Therefore, it is possible to manufacture a battery cell 100 in which the lifespan reduction is minimized even if the liquid electrolyte 160 is reduced after multiple charging and discharging cycles of the battery cell 100.

[0114] Fig. 17 is a front view showing a state in which one side of the containing space 110p1 of the pouch 114 has been further sealed in the method for manufacturing a battery cell 100 according to another embodiment of the present invention, and Fig. 18 is a front view showing a state in which the injection space 110p2 of the pouch 114 has been removed in the method for manufacturing a battery cell 100 according to another embodiment of the present invention.

[0115] 17 and 18 together with FIG. 4, the method for manufacturing a battery cell 100 according to another embodiment of the present invention may further include a step of sealing the receiving space 110p1 of the pouch 114 and a step of cutting the region of the injection space 110p2. Specifically, in the step of sealing the receiving space 110p1 of the pouch 114, the entire boundary between the receiving space 110p1 and the injection space 110p2 of the pouch 114 may be heat-sealed. For example, as shown in FIG. 17, the first outer periphery 114a to the third outer periphery 114c of the pouch 114 may be heat-sealed along the boundary between the receiving space 110p1 and the injection space 110p2 of the pouch 114 to form the sealing portion 111. For example, in the manufacturing method of the battery cell 100 of Figure 8 described above, when a portion between the injection space 110p2 and the storage space 110p1 of the pouch 114 is heat-sealed to form the blocking portion 113, the blocking portion 113 can be heat-sealed to the third outer peripheral portion 114c of the pouch 114 to further form the sealing portion 111.

[0116] Also, a cutting line L may be set on the outside of the sealing portion 111. Then, as shown in FIG 18, the region of the injection space 110p2 of the pouch 114 may be removed by cutting along the cutting line L.

[0117] Furthermore, in the manufacturing method according to another embodiment of the present invention, a battery activation process may be performed before the step of sealing the receiving space 110p1 of the pouch 114 performed in FIG. 17. Here, the battery activation process is a process of performing a charge / discharge operation for the first time in the battery cell 100. A large amount of gas is generated during the charge / discharge operation of the battery cell 100. The generated gas moves from the receiving space 110p1 to the injection space 110p2 and can be discharged to the outside through the opened second outer periphery 114b of the pouch 114. In the battery activation process, the magnitude of the charging current and the charging / discharging time can be changed depending on the materials of the positive electrode 122p and the negative electrode 122n.

[0118] In addition, in the manufacturing method according to another embodiment of the present invention, a battery aging process may be performed after the step of sealing the receiving space 110p1 of the pouch 114. At this time, the temperature may be, for example, 45 to 70 degrees Celsius, and the aging time may be 1 to 3 days.

[0119] Therefore, according to the above-described configuration of the present invention, the method for manufacturing the battery cell 100 of the present invention includes injecting a hardenable electrolyte composition 155 so as to be disposed in a form covering the electrode tab 121, and hardening the hardenable electrolyte composition 155 to form a gel electrolyte 150. As a result, when an external impact is applied to the manufactured battery cell 100, the gel electrolyte 150 covering the electrode tab 121 can prevent the electrode tab 121 from being deformed, as compared with the case where the liquid electrolyte 160 of the battery cell 100 of the prior art covers the electrode tab 121. Therefore, even if frequent impacts and vibrations occurring during movement, such as in an automobile, are transmitted to the battery cell 100, the gel electrolyte 150 can minimize the movement of the electrode tab 121. Therefore, the present invention can prevent the electrode tab 121 from being disconnected due to frequent movement of the electrode tab 121, which can cause the electrical charge and discharge of the electrode 122 to be inactivated.

[0120] That is, the battery cell 100 manufactured by the manufacturing method of the present invention can be manufactured with a gel electrolyte 150 formed in the receiving space 110p1 to cover the electrode tab 121, thereby reducing damage to the electrode tab 121 even when subjected to frequent external impacts, thereby increasing the lifespan of the battery cell 100. In addition, the manufacturing method of the present invention can manufacture a battery cell 100 that can prevent breakage of the electrode tab 121 of the battery cell 100 and prevent reduction in battery capacity during use.

[0121] In addition, it is possible to manufacture a battery cell 100 that can maximize the amount of fluid liquid electrolyte 160 in the space between the accommodation space 110p1 and the electrode assembly 120, thereby minimizing the reduction in lifespan even if the liquid electrolyte 160 between the electrodes 122, etc. decreases after multiple charge / discharge cycles.

[0122] Meanwhile, Fig. 19 to Fig. 22 show a method for manufacturing a battery cell according to another embodiment of the present invention. Specifically, Fig. 19 is a front view showing a step of first injecting a curable electrolyte composition 155 in a method for manufacturing a battery cell in which electrode tabs are led out in a direction facing each other. Fig. 20 is a front view showing a step of first curing the curable electrolyte composition in a method for manufacturing a battery cell according to another embodiment of the present invention. Fig. 21 is a front view showing a step of second injecting the curable electrolyte composition 155 in a method for manufacturing a battery cell according to another embodiment of the present invention. Fig. 22 is a front view showing a step of second curing the curable electrolyte composition 155 in a method for manufacturing a battery cell according to another embodiment of the present invention. For reference, Figs. 19 to 22 are shown transparently so that the inside of the pouch 114 can be seen from the outside for convenience of illustration.

[0123] 19 to 22, in the manufacturing method according to another embodiment of the present invention, unlike the battery cell 100 of FIG. 3 in which the electrode tab 121 is formed only on one side of each of the electrode plates (not shown), the electrode tab 121 of the manufactured battery cell may be formed to face at least two sides of each of the electrode plates (not shown). For example, as shown in FIG. 19, in the manufacturing method of the battery cell according to another embodiment of the present invention, a positive electrode tab 121a and a negative electrode tab 121b are formed on both sides where the electrodes 122 face each other. Thus, as shown in FIG. 19, the positive electrode tab 121a and the negative electrode tab 121b may be located on both sides 120a, 121c of the electrode assembly 120. Also, compared to the pouch 114 of FIG. 9, the pouch 114 of FIG. 19 may further be formed with an additional blocking portion 113a.

[0124] In addition, in the manufacturing method according to another embodiment of the present invention, the injection step of the curable electrolyte composition 155 and the curing step may be repeated for each space on the side of the electrode assembly 120 where the electrode tab 121 is located, among the receiving space 110p1. For example, when the electrode tab 121 is formed on both sides of the electrode 122, etc., as shown in FIG. 19, the injection step of the curable electrolyte composition 155 may be a step of primarily injecting the curable electrolyte composition 155 into the space on one side 120a of the electrode assembly 120 where the electrode tab 121 is located, among the receiving space 110p1. Then, in the curing step, the curable electrolyte composition 155 filled in the receiving space 110p1 on one side 120a of the electrode assembly 120 of the pouch 114 may be primarily cured. After the primary curing step, a secondary curable electrolyte composition 155 injection step of secondarily injecting the curable electrolyte composition 155 into the accommodating space 110p1 of the other side 120c of the electrode assembly 120 where the electrode tab 121 is located, and a secondary curing step of curing the curable electrolyte composition 155 filled in the accommodating space 110p1 of the other side 120c of the electrode assembly 120 may be sequentially performed.

[0125] For example, as shown in FIG. 19, in a battery cell manufactured by a manufacturing method according to another embodiment of the present invention, electrode tabs 121a and 121b may be located on both sides 120a and 120c of an electrode assembly 120. In this case, in the step of injecting the curable electrolyte composition 155, the manufacturing method of the present invention may first inject the curable electrolyte composition 155 into the space facing the first side 120a of the electrode assembly 120 where the electrode tab 121a is located, among the receiving space 110p1 of the pouch 114. After the first injection of the curable electrolyte composition 155, as shown in FIG. 20, the pouch 114 may be rotated so that the electrode tab 121a located on the first side 120a of the electrode assembly 120 is located at a lower position based on the electrode assembly 120. At this time, the blocking part 113 may block the curable electrolyte composition 155 from moving from the receiving space 110p1 to the injection space 110p2. Then, the curable electrolyte composition 155 filled in the space facing the first side 120a of the electrode assembly 120 can be cured until it becomes a gel state (first curing step). After the first curing step, as shown in FIG. 20, the pouch 114 can be rotated and disposed so that the electrode tab 121 located on the first side 120a is located on one side in the X-axis direction based on the electrode assembly 120. Then, the curable electrolyte composition 155 can be secondarily injected into the space facing the third side 120c of the electrode assembly 120 where the positive electrode tab 121b is located, among the receiving space 110p1 of the pouch 114. Furthermore, as shown in FIG. 22, the pouch 114 can be rotated and disposed so that the electrode tab 121 located on the third side 120c is located on the lower side based on the electrode assembly 120. At this time, the curable electrolyte composition 155 can be prevented from moving from the receiving space 110p1 to the injection space 110p2 by the additional blocking part 113a. In addition, the curable electrolyte composition 155 filled in the space located on the third side 120c of the electrodes 122, etc. can be heated to secondarily cure the secondarily injected curable electrolyte composition 155 until it becomes a gel state. The secondarily injected curable electrolyte composition 155 can be transformed into a gel electrolyte 150.

[0126] In another embodiment of the manufacturing method of the present invention, the injected curable electrolyte composition 155 may be secondarily cured until it becomes a gel state to form a gel electrolyte 150, and then the steps of injecting a liquid electrolyte 160, removing the injection space 110p2 of the pouch 114, and sealing the pouch 114 may be further performed.

[0127] Except for the steps described in Figures 19 to 22, the remaining manufacturing steps may be performed similarly to the steps of the manufacturing method according to the other embodiment of the present invention described in Figures 7 to 18. Therefore, the remaining steps for manufacturing a battery cell of the manufacturing method according to the other embodiment of the present invention will be omitted.

[0128] FIG. 23 is a perspective view showing a battery module 1000 according to one embodiment of the present invention.

[0129] 23 together with FIG. 1, the present invention may provide a battery module 1000 including at least one battery cell 100. The battery module 1000 may include a module housing 1100 that accommodates the battery cell (not shown in FIG. 23) therein, an external output terminal 1200 provided at a front end of the module housing 1100, and a control unit 1300 that controls charging and discharging of the battery cell 100. In addition, when the battery module 1000 includes two or more battery cells 100, the battery module 1000 may further include a bus bar (not shown) that electrically connects the two or more battery cells 100. The bus bar may be electrically connected to the electrode lead 130 of each of the battery cells 100. The battery module 1000 of the present invention may include a known configuration other than the battery cell 100, and therefore a description of such a configuration will be omitted.

[0130] Working Example Example 1. (Production of Liquid Electrolyte Composition) A liquid electrolyte was prepared by dissolving LiPF6 at 1.0 M in a non-aqueous organic solvent consisting of ethylene carbonate (EC):ethyl methyl carbonate (EMC) mixed at a volume ratio of 30:70, and then adding vinylene carbonate (VC) at 1 wt% of the total weight of the solvent.

[0131] (Production of Curable Electrolyte Composition) Ethylene carbonate (EC): Ethyl methyl carbonate ( EMC ) in a volume ratio of 30:70, LiPF6 was dissolved in a non-aqueous organic solvent to a concentration of 1.0 M, and then 13 wt% of trimethylolpropane triacrylate was added as a curable compound, 0.06 wt% of AIBN (2,2'-azobis(iso-butyronitrile)) was added as a polymerization initiator, and 1 wt% of vinylene carbonate (VC) was added as another additive to produce a curable electrolyte composition (E1).

[0132] (Manufacturing of electrode assemblies) Cathode active material (Li(Ni) 0.8 Co 0.1 Mn 0.1 )O2), conductive material (carbon black), and binder (polyvinylidene fluoride: PVDF) were added to a solvent N-methyl-2-pyrrolidone (NMP) in a weight ratio of 94:3:3 to prepare a positive electrode active material slurry (solid content 48 wt%). The positive electrode active material slurry was applied to a positive electrode current collector (Al thin film) with a thickness of 15 μm, dried, and then roll pressed to prepare a positive electrode. A negative electrode active material (carbon powder), binder (PVDF), and conductive material (carbon black) were added to a solvent NMP in a weight ratio of 96:3:1 to prepare a negative electrode active material slurry (solid content: 70 wt%). The negative electrode active material slurry was applied to a negative electrode current collector (Cu thin film) with a thickness of 10 μm, dried, and then roll pressed to prepare a negative electrode. The positive electrode, a separator having three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP), and a negative electrode were sequentially stacked to prepare an electrode assembly.

[0133] (Secondary battery manufacturing) The prepared electrode assembly was placed in a pouch, and the prepared curable electrolyte composition (E1) was first injected into a part of the storage space to cover the electrode tab, and then the pouch was stored at a high temperature of 60° C. for 5 hours in a thermostatic chamber to gel the curable electrolyte composition. Then, the prepared liquid electrolyte was secondarily injected into the remaining storage space of the pouch so that the electrode assembly was impregnated, and the pouch was sealed to manufacture a battery cell.

[0134] Example 2. (Production of Curable Electrolyte Composition) Ethylene carbonate (EC): Ethyl methyl carbonate ( EMC ) in a volume ratio of 30:70, LiPF6 was dissolved in a non-aqueous organic solvent to a concentration of 1.0M, and then 33 wt% of trimethylolpropane triacrylate was added as a curable compound, 0.06 wt% of AIBN (2,2'-azobis(iso-butyronitrile)) as a polymerization initiator, and 1 wt% of vinylene carbonate (VC) as another additive were added to produce a curable electrolyte composition (E2).

[0135] (Secondary battery manufacturing) A battery cell was manufactured in the same manner as in Example 1, except that the curable electrolyte composition (E2) prepared above was injected during the injection of the first curable electrolyte composition.

[0136] Example 3. A curable electrolyte composition (E3) was produced in the same manner as in Example 1, except that PVDF-HFP (polyvinylidene-co-hexafluoropropylene) was used as the curable compound instead of trimethylolpropane triacrylate.

[0137] Thereafter, a battery cell was manufactured in the same manner as in Example 1, except that the curable electrolyte composition (E3) prepared above was injected during the injection of the first curable electrolyte composition.

[0138] Comparative Example 1 (No addition of curable compound) (Production of Liquid Electrolyte Composition) A liquid electrolyte was prepared by dissolving LiPF6 at 1.0 M in a non-aqueous organic solvent consisting of ethylene carbonate (EC):ethyl methyl carbonate (EMC) mixed at a volume ratio of 30:70, and then adding vinylene carbonate (VC) at 1 wt% of the total weight of the solvent.

[0139] (Secondary battery manufacturing) A battery cell was manufactured in the same manner as in Example 1, except that the electrode assembly manufactured in Example 1 was housed in a pouch, and then only the prepared liquid electrolyte was poured into the entire inner storage space of the pouch. Specifically, a battery cell was manufactured in which the curable electrolyte composition was not poured, and the step of storing the pouch at a high temperature to harden the curable electrolyte composition was not performed, but the liquid electrolyte was accommodated in the storage space where the electrode tabs were formed in an amount equal to the amount of the curable electrolyte composition.

[0140] Comparative Example 2 (containing gel electrolyte throughout the storage space) Except for the fact that the curable electrolyte composition was injected into the entire storage space including the electrode tabs and the electrode assembly during the production of the secondary battery, a battery cell was produced in the same manner as in Example 1. Specifically, the curable electrolyte composition (E1) was injected into the entire internal space of the pouch including the electrode tabs and the electrode assembly during the first injection, and no liquid electrolyte was injected, except for the fact that the battery cell was produced in the same manner as in Example 1.

[0141] Experimental Example Experimental Example 1. Evaluation of physical stability and capacity retention rate The battery cells prepared in Examples 1 to 3 and the battery cells prepared in Comparative Examples 1 and 2 were each charged at 25° C. under CC-CV (constant voltage-constant current) conditions at 0.33 C C-rate until the V reached 4.2 V, cut off 1 / 20 C, and then discharged at 0.33 C C-rate until the V reached 2.5 V under CC conditions for three cycles, and then the initial discharge capacity was measured.

[0142] Next, the battery cells manufactured in Examples 1 to 3 and the battery cells manufactured in Comparative Examples 1 and 2 were each subjected to a free drop onto a concrete floor from a height of 1 m three times in total. After the three free drops, the battery cells were disassembled, and the number of broken electrode tabs among the electrode tabs was counted and shown in Table 1 below.

[0143] In addition, the battery cells manufactured in Examples 1 to 3 and the battery cells manufactured in Comparative Examples 1 and 2 that were subjected to the free fall were charged under CC-CV (constant voltage-constant current) conditions at 0.33C C-rate at 25° C. until they reached 4.2V, and after 1 / 20C cut-off, they were discharged under CC conditions at 0.33C C-rate until they reached 2.5V, and the discharge capacity after the free fall was measured. The capacity retention rate (%) was calculated using the following formula 1, and the results are shown in Table 1 below. [Formula 1] Capacity retention rate (%) = (discharge capacity after free fall / initial discharge capacity) x 100

[0144] [Table 1]

[0145] From Table 1, it can be seen that in the battery cells manufactured in Examples 1 to 3 in which a gel electrolyte is formed around the electrode tab and the battery cell manufactured in Comparative Example 2, the physical stability of the tab area is improved and the electrode tab does not break even after the battery cell is dropped freely, compared to the battery cell of Comparative Example 1 in which no gel electrolyte is included.

[0146] Meanwhile, as a result of evaluating the cell capacity after the free fall, it was confirmed that the existing capacity was almost fully realized in the battery cells manufactured in Examples 1 to 3 in which no breakage of the electrode tabs occurred and the battery cell manufactured in Comparative Example 2, whereas a significant capacity reduction occurred in the battery cell manufactured in Comparative Example 1 in which breakage of the electrode tabs occurred.

[0147] Experimental example 2. Evaluation of internal resistance For electrochemical evaluation (internal resistance), the battery cells manufactured in Examples 1 to 3 and the battery cells manufactured in Comparative Examples 1 and 2 were charged to SOC 50% at 0.33 C-rate CC, and then a current of about 2.5 C was applied for 10 seconds to measure the voltage drop, and the internal resistance was calculated using the following Equation 2. The internal resistance increase rate (%) of the battery cells manufactured in Examples 1 to 3 and the battery cell manufactured in Comparative Example 2 was calculated based on the internal resistance value of the battery cell in Comparative Example 1 (100%), and the results are shown in Table 2. [Formula 2] R = V / I, Here, R is resistance, V is voltage (potential difference), and I is current.

[0148] Experimental example 3: Evaluation of high-temperature cycle characteristics The battery cells prepared in Examples 1 to 3 and the battery cell prepared in Comparative Example 2 were charged at 25° C. under CC-CV (constant current-constant voltage) conditions at a rate of 0.33 C to 4.2 V, and discharged under CC conditions at a rate of 0.33 C to 2.5 V after a 1 / 20 C cut-off. The above charge and discharge constitute one cycle, and an initial charge and discharge (activation) process was performed for three cycles.

[0149] Then, each of the lithium secondary batteries that had been initially charged and discharged at high temperature (45° C.) was charged under CC-CV conditions at a rate of 0.33 C up to 4.2 V, cut off at 1 / 20 C, and then discharged under CC conditions at a rate of 0.33 C up to 2.5 V, which constituted one cycle. 100 cycles were performed.

[0150] The capacity after the initial charge / discharge and the capacity after the 100th cycle were substituted into the following formula 3 to calculate the capacity retention rate, and the results are shown in Table 2 below. [Formula 3] Capacity retention rate (%) = (discharge capacity after 100th cycle / discharge capacity after initial charge / discharge) × 100

[0151] [Table 2]

[0152] From Table 2, it can be seen that in the battery cells manufactured in Examples 1 to 3, since the gel electrolyte is present only in the electrode tab portion, the resistance is somewhat increased compared to the battery cell of Comparative Example 1 having only a liquid electrolyte. However, the internal resistance is significantly reduced compared to the battery cell of Comparative Example 2 in which the gel electrolyte is formed in the portion other than the electrode tab receiving area, i.e., in the entire receiving space including the electrode tab and the electrode assembly.

[0153] In addition, from examining Table 2, it can be seen that in the case of the battery cells manufactured in Examples 1 to 3, the capacity retention rate (%) after the high temperature cycle characteristics was significantly improved compared to the battery cell of Comparative Example 2 due to the reduction in internal resistance.

[0154] Based on these results, it can be seen that when a battery cell is manufactured including a curable electrolyte composition to which an appropriate amount of the curable compound of the present invention is added and which is arranged in a form covering an electrode tab, the durability of the battery cell can be improved and deterioration of the battery performance of the battery cell can be reduced.

[0155] As described above, even if the embodiments are described by limited drawings, a person having ordinary skill in the art may apply various technical modifications and variations from the above description. For example, the described techniques may be performed in an order different from that described, and / or the components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different manner from that described, or may be replaced or substituted by other components or equivalents, and still achieve suitable results.

[0156] Accordingly, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims. [Explanation of symbols]

[0157] 100: Battery cell 1000: Battery module 110: Cell case 110p1, 110p2: storage space, injection space 113, 113a: interrupting section, additional interrupting section 114, 114T, 114P: Pouch, 1st cell sheet, 2nd cell sheet 114a, 114b, 114c, 114d: first outer circumference, second outer circumference, third outer circumference, fourth outer circumference 120, 122, 122p, 122n, 170: Electrode assembly, electrode, positive electrode, negative electrode, separation membrane 120a, 120b, 120c, 120d: first side, second side, third side, fourth side 121, 121a, 121b: electrode tab, positive electrode tab, negative electrode tab 130, 130a, 130b: electrode lead, positive electrode lead, negative electrode lead 140: Insulating film 111: Sealing part 150: Gel electrolyte 155: Curable electrolyte composition 160:Liquid electrolyte 210: Fixed jig 211, 212, 213: Base, first jig plate, second jig plate 214, 214a, 214b: 1st support stand, pillar part, connection part 215, 215a, 215b: 2nd support stand, pillar part, connection part 180: Blocking member (tongue member) 181: Finger of tong component

Claims

1. A cell case having a storage space; an electrode assembly in which a plurality of electrode plates and separators are alternately stacked and housed in the housing space; an electrode tab extending outward from the electrode plate and electrically connecting the electrode plate to an external terminal; a gel electrolyte that is accommodated in the accommodation space to cover the electrode tab and prevent the electrode tab from moving; and a liquid electrolyte contained in the containing space so as to surround the other side of the electrode assembly on which the electrode tab is not formed.

2. the gel electrolyte is contained only in the peripheral region of the electrode tab; The battery cell according to claim 1 , wherein the liquid electrolyte is contained in a remaining space of the containing space that is not filled with the gel electrolyte.

3. 2. The battery cell of claim 1, wherein the gel electrolyte contains a hardened polymer in a content of 3 wt% to 30 wt%.

4. 2. The battery cell of claim 1, wherein the gel electrolyte is received in the receiving space to impregnate the side of the electrode assembly on which the electrode tab is formed, and a depth of the side of the electrode assembly impregnated with the gel electrolyte is 10 mm or less.

5. A battery module comprising at least one battery cell according to claim 1 .

6. A method for manufacturing a battery cell according to any one of claims 1 to 4, comprising the steps of: providing an electrode assembly including a plurality of electrode plates having electrode tabs formed on at least one side thereof and a separator interposed between the electrode plates; placing the electrode assembly in a receiving space of a pouch; injecting a curable electrolyte composition into the receiving space of the pouch through the injection space of the pouch so as to cover the electrode tabs; converting the hardenable electrolyte composition into a gel electrolyte in a gel phase to prevent flow of the electrode tabs; and A method of manufacturing a battery cell, comprising: injecting a liquid electrolyte into the receiving space so as to surround the other side of the electrode assembly on which the electrode tab is not formed.

7. The method of claim 6 , wherein the curable electrolyte composition comprises a curable compound in a content of 3 wt % to 30 wt %.

8. 7. The method of claim 6, wherein the step of converting the curable electrolyte composition into a gel electrolyte in a gel phase comprises a step of thermally curing, ultraviolet light curing, or radiation curing the curable electrolyte composition.

9. Prior to the step of injecting the curable electrolyte composition, The method for manufacturing a battery cell according to claim 6 , further comprising forming a blocking portion configured to block migration of the curable electrolyte composition from the receiving space to the injection space.

10. The step of forming the blocking portion includes:

10. The method of claim 9, further comprising forming the blocking portion to extend from an outer periphery of the pouch along a boundary between the receiving space and the injection space and to protrude further inward of the electrode assembly than one side end of the electrode assembly where the electrode tab is located.

11. The step of forming the blocking portion includes:

10. The method for manufacturing a battery cell according to claim 9, further comprising the step of melt-joining a portion between the injection space and the storage space of the pouch, or pressurizing and forming a portion between the storage space and the injection space of the pouch.

12. prior to the step of converting the curable electrolyte composition into a gel electrolyte in a gel phase to prevent flow of the electrode tabs, The method of claim 6 , further comprising the step of pressurizing and fixing the pouch and the electrode assembly using a jig plate outside the pouch to fix a shape of the curable electrolyte composition.

13. 7. The method of claim 6, wherein the step of preventing the electrode tab from moving by changing the hardenable electrolyte composition into a gel electrolyte in a gel phase is performed in a state where the pouch and the electrode assembly are pressurized and fixed.

14. The step of injecting the curable electrolyte composition includes:

7. The method of claim 6, further comprising: arranging the pouch and the electrode assembly such that the electrode tab is located at a lower portion of the electrode assembly, and using gravity to accommodate the hardenable electrolyte composition so as to cover the electrode tab.

15. The method of manufacturing a battery cell according to claim 6 , further comprising the step of rotating the pouch so that the electrode tab is located at a side of the electrode assembly before the step of injecting the liquid electrolyte.

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