Apparatus for activating battery cell and method for activating battery cell using same

Abstract

According to exemplary embodiments of the present invention, a battery cell activation device is provided. The device includes: a driving part including a driving plate and driving rods configured to move the driving plate in a first direction; and a support part including a support plate and elastic elements connected to the support plate, wherein the support plate is spaced apart from the driving plate in the first direction and includes protrusion parts protruding in the first direction.

Description

Battery cell activator and method for activating a battery cell using the same

[0001] The present invention relates to a battery cell activator and a method for activating a battery cell using the same. This application claims the benefit of Korean Application No. 10-2023-0176240, filed December 7, 2023, which is incorporated herein by reference in its entirety.

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0003] The manufacturing of secondary batteries includes electrode processes, including mixing, coating, roll pressing, slitting, and notching; an assembly process, which embeds the electrode assembly in a case; and an activation process, which electrically activates and stabilizes the battery cells. After the activation process, the battery cells can be stacked to form a cell stack. The cell stack can be mounted in a housing with a module frame, or directly in the housing without a module frame.

[0004] The technical idea of ​​the present invention aims to solve a problem by providing a battery cell activation device with improved reliability and a method for activating a battery cell using the same.

[0005] According to exemplary embodiments of the present invention for solving the above-described problem, a battery cell activation device is provided. The device comprises: a driving unit including a driving plate and driving rods configured to move the driving plate in a first direction; a supporting unit including a supporting plate and elastic elements connected to the supporting plate, the supporting plate being spaced apart from the driving plate in the first direction; and a plurality of pressing plates interposed between the driving unit and the supporting plate and configured to pressurize a plurality of battery cells, and the supporting plate including protrusions protruding in the first direction.

[0006] The height of each of the above protrusions in the first direction is in the range of 0.1 mm to 1.0 mm.

[0007] The height of each of the above protrusions in the first direction is 0.6 mm or less.

[0008] Each of the above protrusions comprises the same material as the support plate.

[0009] Each of the above protrusions comprises a different material than the support plate.

[0010] The above protrusions are spaced apart from the center of the support plate.

[0011] The protrusions are spaced apart from each other in a second direction parallel to the support plate, and the protrusions are spaced apart from the center of the support plate in the second direction.

[0012] The distance between the ends of the support plate in the second direction and the protrusions is different from the distance between the protrusions and the center of the support plate in the second direction.

[0013] The distance between the ends of the support plate in the second direction and the protrusions is smaller than the distance between the protrusions and the center of the support plate in the second direction.

[0014] Each of the above pressure plates has a flat plate shape.

[0015] Each of the above pressure plates does not include a protrusion.

[0016] Each of the above pressure plates has a different surface shape from the support plate.

[0017] According to exemplary embodiments, a method for activating a secondary battery is provided. The method comprises the steps of: loading a plurality of pressure sensitive papers and a plurality of battery cells into a battery cell activating device; performing an activation process on the plurality of battery cells; and evaluating the activation process of the plurality of battery cells based on the pressure sensitive paper, wherein the battery cell activating device comprises: a driving unit including a driving plate and driving rods configured to move the driving plate in a first direction; and a supporting unit including a support plate and elastic elements connected to the support plate, wherein the support plate is spaced apart from the driving plate in the first direction; and the support plate includes protrusions protruding in the first direction.

[0018] The above activation process is evaluated based on the standard deviation of the pressure detected by the pressure sensor.

[0019] A battery cell activation device according to exemplary embodiments of the present invention includes a support plate including a protrusion. Accordingly, the battery cells can be evenly pressed during the activation process, thereby improving the reliability of secondary battery manufacturing.

[0020] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0021] FIG. 1 is a plan view of a battery cell activation device according to exemplary embodiments.

[0022] FIG. 2 is a partial plan view of a battery cell activation device according to exemplary embodiments.

[0023] FIG. 3 is a flowchart illustrating a method for manufacturing a secondary battery according to exemplary embodiments.

[0024] Figure 4 illustrates a pressure relief according to exemplary embodiments.

[0025] Figure 5 illustrates a pressure relief according to exemplary embodiments.

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0027] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0028] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0029] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0030]

[0031] (Example 1)

[0032] FIG. 1 is a perspective view of a battery cell activation device (100) according to exemplary embodiments.

[0033] Referring to FIG. 1, a battery cell activation device (100) may include a driving unit (110), a support unit (120), and a plurality of pressure plates (130).

[0034] According to exemplary embodiments, a battery cell activation device (100) may be configured to perform an activation (Formation) process of battery cells (BC). Here, the activation process of battery cells (BC) may include repetition of aging, charging, and discharging of the battery cells (BC).

[0035] As the electrolyte decomposes due to repeated charging and discharging, a Solid Electrolyte Interphase (SEI) film may form on the surface of the negative electrode. SEI is a thin film that forms on the surface of the negative electrode material when the battery cells (BC) are first charged after manufacturing. When the battery cells (BC) are charged, lithium ions inside the battery cells (BC) move to the negative electrode, and during this process, the substances in the electrolyte are electrolyzed for the first time, resulting in a chemical reaction that can form an SEI film on the surface of the negative electrode material. SEI can be a type of separator. SEI can prevent further decomposition reactions of the electrolyte during the process of lithium ions moving from the positive electrode to the negative electrode for battery charging.

[0036] During the aging process, the charged or discharged battery cells (BC) can be stored at room temperature for a predetermined period of time (for example, 30 minutes to 3 hours) to stabilize them. The key to the aging process is to evenly distribute the electrolyte within the pouch cell so that it permeates both the positive and negative electrodes. The aging process can improve lithium ion mobility and enhance the uniformity (e.g., thickness uniformity) of the SEI film.

[0037] The activation process for battery cells (BC) may include degassing, which removes gases generated within the battery during aging and charging. Gases may be generated within the battery cells (BC) during the charging / discharging and aging processes. The degassing process removes these gases from within the battery cells (BC).

[0038] While the battery cells (BC) are being charged and discharged, the battery cells (BC) can be pressurized by the pressurized plates. Uniform pressurization of the battery cells (BC) can prevent gas traps and lithium plating, and improve the uniformity of the SEI film. Battery cells (BC) including a uniform SEI film can have a relatively short charge or discharge time.

[0039] Battery cells (BC) are the basic units of a lithium-ion battery, i.e., a secondary battery. The battery cells (BC) may be pouch-shaped. The battery cells (BC) may include a pouch case (PC) and an electrode assembly built into the pouch case (PC). The electrode assembly built into the pouch case (PC) includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The positive electrode may include a positive electrode tab connected to one of the electrode leads (EL), and the negative electrode may include a negative electrode tab connected to one of the electrode leads (EL).

[0040] A pouch case (PC) can be provided by performing a forming process and a sealing process on a pouch film. The pouch film can include an inner resin layer, a metal layer, and an outer resin layer. The inner resin layer can have heat-adhesive properties, thereby enabling the pouch film to be sealed. The inner resin layer can include, for example, a polyolefin-based material. The metal layer can include any one of an alloy of iron, carbon, chromium, and manganese, an alloy of iron, chromium, and nickel, and aluminum.

[0041] The electrode assembly may be, but is not limited to, either a jelly-roll type or a stack type. The jelly-roll type electrode assembly includes a rolled positive electrode, a negative electrode, and a separator interposed therebetween. The stack type electrode assembly includes a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed therebetween. The battery cells (BC) of FIG. 1 may be workpieces prior to an activation process after undergoing a pouch forming process and an electrolyte injection process.

[0042] The positive electrode may include a positive current collector and a positive active material. The negative electrode may include a negative current collector and a negative active material.

[0043] The thickness of the positive electrode current collector may range from about 3 μm to about 500 μm. The positive electrode current collector may not cause chemical changes in the secondary battery to be ultimately manufactured and may have high conductivity. The positive electrode current collector may include, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, and aluminum. The positive electrode current collector may also include stainless steel surface-treated with carbon, nickel, titanium, silver, or the like. The surface of the positive electrode current collector may include a micro-roughened structure to increase the adhesion of the active material. The positive electrode current collector may have a shape such as a film, a sheet, a foil, a net, a porous material, a foam, or a non-woven fabric.

[0044] The thickness of the negative electrode current collector may be in the range of about 3 μm to about 500 μm. The negative electrode current collector may not cause chemical changes in the secondary battery ultimately manufactured and may have high conductivity. The negative electrode current collector may include copper, stainless steel, aluminum, nickel, titanium, sintered carbon, and an aluminum-cadmium alloy. The negative electrode current collector may also include stainless steel surface-treated with carbon, nickel, titanium, silver, etc. The surface of the negative electrode current collector may include a micro-roughened structure to increase the adhesion of the active material. The negative electrode current collector may have a shape such as a film, a sheet, a foil, a net, a porous material, a foam, or a non-woven fabric.

[0045] A cathode active material is a material capable of causing an electrochemical reaction. The cathode active material may be a lithium transition metal oxide. Examples of the cathode active material include layered compounds such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2) substituted with one or more transition metals; lithium manganese oxide substituted with one or more transition metals; chemical formula LiNi 1-y M y Lithium nickel oxide expressed as O2 (wherein, M is any one of Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn, and Ga, and 0.01≤y≤0.7); Li 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, Li 1+zN i 0.4 Mn 0.4 Co 0.2 Li like O2 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A e(wherein, -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2, 0≤e≤0.2, b+c+d<1, M is any one of Al, Mg, Cr, Ti, Si, and Y, and A is any one of F, P, and Cl) Lithium nickel cobalt manganese composite oxide; chemical formula Li 1+x M 1-y M' y PO 4-z X z (wherein, M is a transition metal, more specifically, one of Fe, Mn, Co, and Ni, M' is one of Al, Mg, and Ti, X is one of F, S, and N, -0.5≤x≤+0.5, 0≤y≤0.5, and 0≤z≤0.1) and may include an olivine-based lithium metal phosphate.

[0046] The negative active material may include carbon, such as non-graphitizable carbon, graphitic carbon, etc. The negative active material may include, for example, Li x Fe2O3(0≤x≤1), LixWO2(0≤x≤1), Sn x Me 1-x Me' y O z (wherein Me is any one of Mn, Fe, Pb and Ge, and Me' is any one of Al, B, P, Si, elements of group 1, 2 and 3 of the periodic table and halogens; 0 <x≤1 이고; 1≤y≤3 이며; 1≤z≤8) 등의 금속 복합 산화물을 포함할 수 있다. 음극 활물질은, 예컨대, 리튬 금속; 리튬 합금; 규소계 합금; 주석계 합금을 포함할 수 있다. 음극 활물질은, 예컨대, SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5등의 금속 산화물을 포함할 수 있다. 음극 활물질은, 예컨대, 폴리아세틸렌 등의 도전성 고분자; Li-Co-Ni 계 재료 등을 포함할 수 있다.

[0047] According to exemplary embodiments, the drive unit (110) may include a drive plate (111) and drive rods (116). The drive rods (116) may be configured to transmit an external driving force to the drive plate (111). The drive rods (116) may be connected to, for example, a hydraulic cylinder or a linear servo motor. The drive plate (111) may have a generally flat plate shape. The drive plate (111) may be substantially perpendicular to the X direction. The drive plate (111) may be substantially parallel to the Y direction. The drive rods (116) may be configured to move the drive plate (111) in the X direction.

[0048] The support member (120) may include a support plate (121) and elastic elements (126). The support plate (121) may be spaced apart from the drive plate (111) in the X direction. The support plate (121) may be substantially parallel to the drive plate (111). The support plate (121) may be substantially parallel to the Y direction. The support plate (121) may be substantially perpendicular to the X direction.

[0049] The elastic elements (126) may be coupled to the second surface (121S2) of the support plate (121). The axis of the elastic force of the elastic elements (126) may be substantially parallel to the X direction. That is, each of the elastic elements (126) may apply an elastic force in the X direction proportional to the displacement in the X direction to the support plate (121). By each of the elastic elements (126), a pressure of an appropriate strength may be applied to the plurality of battery cells (BC). The elastic elements (126) may be directly or indirectly connected to a sensor such as a load cell, and the pressure applied to the battery cells (BC) may be controlled based on the elastic force of the elastic elements (126).

[0050] The support plate (121) may include steps (121P). Each of the steps (121P) may be spaced apart from the center of the support plate (121) (more specifically, the center in the Y direction). Each of the steps (121P) may be at an edge portion of the support plate (121). Each of the steps (121P) may be closer to the end portion of the support plate (121) in the Y direction than to the center of the support plate (121) in the Y direction.

[0051] The distance between the Y-direction ends of the support plate (121) and the steps (121P) may be different from the distance between the Y-direction center of the support plate (121) and the steps (121P). The distance between the Y-direction ends of the support plate (121) and the steps (121P) may be smaller than the distance between the Y-direction center of the support plate (121) and the steps (121P).

[0052] The distance between the steps (121P) and the end portions of the support plate (121) in the Y direction may be different from the distance between the center of the support plate (121) in the Y direction and the steps (121P). The distance between the steps (121P) and the end portions of the support plate (121) in the Y direction may be smaller than the distance between the center of the support plate (121) in the Y direction and the steps (121P).

[0053] The steps (121P) may protrude in the X direction from the first surface (121S1) of the support plate (121). The first surface (121S1) of the support plate (121) may face the driving plate (111). The first surface (121S1) of the support plate (121) may face the pressure plates (130). Accordingly, the steps (121P) may be configured to pressurize an edge portion of a battery cell (BC) interposed between the support plate (121) and the pressure plates (130) (i.e., a battery cell (BC) in contact with the pressure plate (130).

[0054] According to exemplary embodiments, each of the steps (121P) may comprise the same material as the support plate (121). For example, each of the steps (121P) may be a continuous element integrally formed with the support plate (121). For example, each of the steps (121P) may comprise aluminum. In another example, the steps (121P) may comprise a material having a lower hardness than the support plate (121). This may be a silicone pad. For example, each of the steps (121P) may comprise silicone.

[0055] During the activation process, uniform pressurization of the battery cells (BC) suppresses lithium plating, and thus uniform pressurization of the battery cells (BC) is one of the key factors in managing the performance of the battery cells (BC). The pressure applied to the battery cells (BC) adjacent to the support plate (121) may be relatively uneven compared to the pressure applied to the battery cells (BC) adjacent to the drive plate (111). Accordingly, the pressure applied to the edge portions of the battery cells (BC) by the support plate (121) may be less than the pressure applied to the center portions of the battery cells (BC) by the support plate (121). According to exemplary embodiments, the battery cells (BC) in contact with the support plate (121) may be uniformly pressurized by the steps (121P) protruding from the edge of the support plate (121), and thus, the reliability of secondary battery manufacturing may be improved.

[0056] According to exemplary embodiments, the height (122H) of each of the steps (121P) may be in a range of about 0.1 mm to about 1 cm. According to exemplary embodiments, the height (122H) of each of the steps (121P) may be about 0.2 mm or more. According to exemplary embodiments, the height (122H) of each of the steps (121P) may be about 0.3 mm or more. According to exemplary embodiments, the height (122H) of each of the steps (121P) may be about 0.4 mm or more. According to exemplary embodiments, the height (122H) of each of the steps (121P) may be about 0.9 mm or less. According to exemplary embodiments, the height (122H) of each of the steps (121P) may be about 0.8 mm or less. According to exemplary embodiments, the height (122H) of each of the steps (121P) may be about 0.7 mm or less. According to exemplary embodiments, the height (122H) of each of the steps (121P) may be about 0.6 mm or less.

[0057] Here, the Y direction may be an extension direction of the pouch case (PC) of the battery cells (BC). The main surface of the pouch case (PC) of the battery cells (BC) may be substantially parallel to the Y direction and substantially perpendicular to the X direction. The electrode leads (EL) of each of the battery cells (BC) may be spaced apart in the Y direction, but are not limited thereto.

[0058] According to exemplary embodiments, the pressure plates (130) may be interposed between the drive plate (111) and the support plate (121). Each of the pressure plates (130) may be substantially parallel to the drive plate (111). Each of the pressure plates (130) may be substantially perpendicular to the X-direction. Each of the pressure plates (130) may be substantially perpendicular to the X-direction.

[0059] Each of the pressure plates (130) can be coupled to a shaft extending in the X direction. Accordingly, the pressure plates (130) can be moved along the shaft by driving the driving plate (111). A plurality of battery cells (BC) can be inserted between the pressure plates (130), and the plurality of battery cells (BC) can be pressed by the pressure plates (130), the driving plate (111), and the support plate (121).

[0060] Each of the pressure plates (130) may have a flat shape. Accordingly, each of the pressure plates (130) may not include a step. Each of the two main surfaces of each of the pressure plates (130) may be different from the first surface (121S1) of the support plate (121).

[0061] The battery cell activator (100) may further include charging terminals configured to be electrically connected to electrode leads (EL) of a plurality of battery cells (BC). The charging terminals may be in contact with the electrode leads (EL) of the plurality of battery cells (BC). The charging terminals may be configured to transmit external power to the plurality of battery cells (BC).

[0062]

[0063] (Example 2)

[0064] FIG. 3 is a flowchart illustrating a method for manufacturing a secondary battery according to exemplary embodiments.

[0065] Figure 4 illustrates a pressure relief according to exemplary embodiments.

[0066] Figure 5 illustrates a pressure relief according to exemplary embodiments.

[0067] Referring to FIGS. 3 to 5, at P110, a plurality of pressure sensitive substrates (PSS) and battery cells (BC) can be loaded into a battery cell activation device (100). The loading of the battery cells (BC) can be performed by a pick and place machine.

[0068] Pressure-sensitive paper (PSS) may include microcapsules containing dye. When pressure is applied to the PSS, the dye embedded in the capsules of the PSS may be released by the pressure, and the PSS may display characters or colors due to the reaction of the dye with a developer on the surface of the PSS. As illustrated in FIGS. 4 and 5, the PSS may simultaneously display a color and characters indicating the applied pressure, or may display only one of the colors and characters indicating the applied pressure.

[0069] Next, at P120, an activation process can be performed on a plurality of battery cells (BC). The activation process of the plurality of battery cells (BC) can include a plurality of charge / discharge and aging processes, as described above.

[0070] Next, at P130, the activation process of the plurality of battery cells (BC) can be evaluated. The activation process of the plurality of battery cells (BC) can be evaluated based on the pressure sensitive sheets (PSS). While the plurality of battery cells (BC) are being processed, the pressure sensitive sheets (PSS) can be pressurized together with the plurality of battery cells (BC). Accordingly, after the activation process is completed, each of the pressure sensitive sheets (PSS) can indicate the pressure applied to the surface of the corresponding one of the plurality of battery cells (BC). For example, the pressure sensitive sheet (PSS) of FIG. 4 shows a more even pressure distribution than the pressure sensitive sheet (PSS) of FIG. 5, and therefore, the processing of the battery cell (BC) corresponding to the pressure sensitive sheet (PSS) of FIG. 5 is more preferable than the processing of the battery cell (BC) corresponding to the pressure sensitive sheet (PSS) of FIG. 4.

[0071] In exemplary embodiments, evaluating the activation process may include evaluating the uniform pressurization of the plurality of battery cells (BC). In exemplary embodiments, evaluating the activation process may be based on the standard deviation of the readings of the pressure sensitive paper (PSS). In exemplary embodiments, evaluating the activation process may include comparing the standard deviation of the readings of the pressure sensitive paper (PSS) to a threshold standard deviation. For example, if the standard deviation of the readings of the pressure sensitive paper (PSS) is less than or equal to the threshold standard deviation, the resulting battery cell (BC) of the activation process may be determined to be good, and, for example, if the standard deviation of the readings of the pressure sensitive paper (PSS) is greater than the threshold standard deviation, the resulting battery cell (BC) of the activation process may be determined to be bad.

[0072] A person skilled in the art will readily be able to arrive at an embodiment in which a pressure sensitive sheet (PSS) is provided only to the battery cell (BC) between the support plate (121) and the pressure plate (130) based on what is described herein.

[0073]

[0074] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. A driving unit including a driving plate and driving rods configured to move the driving plate in a first direction; A support member comprising a support plate and elastic elements connected to the support plate, wherein the support plate is spaced apart from the driving plate in the first direction; and It comprises a plurality of pressurizing plates interposed between the driving unit and the support plate and configured to pressurize a plurality of battery cells, A battery cell activating device, characterized in that the support plate includes protrusions protruding in the first direction.

2. In paragraph 1, A battery cell activator, characterized in that the height of each of the above protrusions in the first direction is in a range of 0.1 mm to 1.0 mm.

3. In paragraph 1, A battery cell activating device, characterized in that each of the above protrusions has a height of 0.6 mm or less in the first direction.

4. In paragraph 1, A battery cell activating device, wherein each of the protrusions comprises the same material as the support plate.

5. In paragraph 1, A battery cell activating device, wherein each of the above protrusions comprises a different material from the support plate.

6. In paragraph 1, A battery cell activator device, characterized in that the protrusions are spaced apart from the center of the support plate.

7. In paragraph 1, The above protrusions are spaced apart from each other in a second direction parallel to the support plate, and A battery cell activator, characterized in that the protrusions are spaced apart from the center of the second direction of the support plate.

8. In paragraph 7, A battery cell activator, characterized in that the distance between the ends of the second direction of the support plate and the protrusions is different from the distance between the protrusions and the center of the second direction of the support plate.

9. In paragraph 7, A battery cell activator, characterized in that the distance between the ends of the second direction of the support plate and the protrusions is smaller than the distance between the protrusions and the center of the second direction of the support plate.

10. In paragraph 1, A battery cell activating device, wherein each of the above pressure plates has a flat plate shape.

11. In paragraph 1, A battery cell activating device, wherein each of the above pressure plates does not include a protrusion.

12. In paragraph 1, A battery cell activating device, wherein each of the above pressurizing plates has a different surface shape from the support plate.

13. A step of loading a plurality of pressure sensitive devices and a plurality of battery cells into a battery cell activator; A step of performing an activation process on a plurality of battery cells; and A step of evaluating the activation process of the plurality of battery cells based on the above pressure sensitive region, The battery cell activating device comprises a driving member including a driving plate and driving rods configured to move the driving plate in a first direction, and a supporting member including a supporting plate and elastic elements connected to the supporting plate, wherein the supporting plate is spaced apart from the driving plate in the first direction; and A method for activating a secondary battery, wherein the support plate includes protrusions protruding in the first direction.

14. In paragraph 13, A method for activating a secondary battery, characterized in that the above activation process is evaluated based on the standard deviation of the pressure detected by the pressure reducing device.

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