Secondary battery

Abstract

Provided is a secondary battery including: an electrode assembly manufactured in a layering and folding method; and a case accommodating the electrode assembly, wherein the electrode assembly includes six or more unit cells attached to a folded separator, each of the six or more unit cells has one surface attached to the folded separator, and the unit cells are arranged such that, when the electrode assembly is unfolded, the number of negative electrodes among electrodes of each unit cell, the other surface of which is not attached to the folded separator, is minimized.

Description

Technical Field

[0001] This disclosure relates to secondary batteries, and more specifically to secondary batteries with extended lifespan.

[0002] This application claims the benefit of Korean Patent Application No. 10-2024-0045248, filed on April 3, 2024, the disclosure of which is incorporated herein by reference. Background Technology

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries are rechargeable and dischargeable, and are widely used in electronic devices such as cell phones, laptops, portable cameras, and electric vehicles. In particular, lithium secondary batteries have a larger capacity than nickel-cadmium or nickel-metal hydride batteries, and they also have a higher energy density per unit weight, thus their use is rapidly increasing.

[0004] Various structural and / or manufacturing methods have been proposed and applied to produce secondary batteries, and various efforts have been made to increase the lifespan of secondary batteries. Summary of the Invention

[0005] Technical issues

[0006] The technical challenge of this disclosure is to provide a rechargeable battery with an extended lifespan.

[0007] Technical solution

[0008] This disclosure addresses the aforementioned technical problems by providing a secondary battery comprising: an electrode assembly manufactured in a stacked and folded manner; and a housing accommodating the electrode assembly, wherein the electrode assembly includes six or more cell units attached to a folded separator, each of the six or more cell units having one surface attached to the folded separator, wherein the cell units are arranged such that when the electrode assembly is unfolded, the number of negative electrodes forming other surfaces of the cell units is minimized, wherein the other surfaces are not attached to the folded separator.

[0009] In some embodiments, the outermost cell on both sides of the electrode assembly each has a stacked structure of single-sided positive electrode / separator / negative electrode / separator / positive electrode.

[0010] In some embodiments, the electrode assembly is configured such that the electrodes of a pair of cell cells facing each other across the folded diaphragm have different polarities.

[0011] In some embodiments, the electrode assembly includes at least one single cell.

[0012] In some embodiments, the electrode assembly includes eight or more individual cells, and the number of individual cells is less than half the total number of all individual cells.

[0013] In some embodiments, the electrode assembly is manufactured by arranging six or more cell units on the folded diaphragm and then folding the folded diaphragm by attaching one surface of the cell units to the folded diaphragm.

[0014] In some embodiments, a cell with a positive electrode on both sides of a negative electrode and a separator between the electrodes is defined as type A; a cell with a negative electrode on both sides of a positive electrode and a separator between the electrodes is defined as type C; a cell with a single positive electrode and a positive electrode on both sides of a negative electrode, a separator between the electrodes, and the tab of the single positive electrode on the right side is defined as type R; a cell with a single positive electrode and a positive electrode on both sides of a negative electrode, a separator between the electrodes, and the tab of the single positive electrode on the left side is defined as type L; a cell with a negative electrode and a positive electrode on both sides of a separator, and the tab of the positive electrode on the right side is defined as type MR; and a cell with a negative electrode and a positive electrode on both sides of a separator, and the tab of the positive electrode on the left side is defined as type ML.

[0015] In some embodiments, the electrode assembly includes twelve unit cells, and wherein when the electrode assembly is deployed, the unit cells are arranged in one of the following arrangements: RLC-MR-A-MR-C-MR-ACCA; RL-ML-C-ML-A-ML-CCAAC.

[0016] In some embodiments, the electrode assembly includes eleven cell units, and wherein, when the electrode assembly is deployed, the cell units are arranged in one of the following arrangements: RLC-MR-A-MR-CCAAC; RL-ML-C-ML-ACCAAC; RL-ML-C-ML-ML-ML-ACCA; RLC-MR-MR-MR-A-MR-CCA.

[0017] In some embodiments, the electrode assembly includes ten unit cells, and wherein when the electrode assembly is deployed, the unit cells are arranged in the following order: RL-ML-C-ML-A-ML-CCA.

[0018] In some embodiments, the electrode assembly includes nine unit cells, and wherein, when the electrode assembly is deployed, the unit cells are arranged in one of the following arrangements: RLC-MR-A-MR-CCA; RL-ML-C-ML-ACCA; RL-ML-C-ML-ML-ML-AC.

[0019] In some embodiments, the electrode assembly includes seven cell units, wherein when the electrode assembly is deployed, the cell units are arranged in the following order: RL-ML-MR-ML-MR-C.

[0020] Beneficial effects

[0021] The secondary battery disclosed herein has the effect of extending the life of the secondary battery by maximally suppressing the deposition of dendritic lithium in secondary batteries manufactured by stacking and folding methods.

[0022] The effects obtainable from the exemplary embodiments of this disclosure are not limited to those described above, and those skilled in the art to which the exemplary embodiments of this disclosure pertain will clearly derive and understand other effects not mentioned in the following description. In other words, those skilled in the art can also derive undesirable effects from practicing the exemplary embodiments of this disclosure. Attached Figure Description

[0023] Figure 1 This is an exploded perspective view of a secondary battery according to one embodiment of the present disclosure.

[0024] Figure 2 This is a conceptual diagram illustrating a method for manufacturing electrode assemblies using layering and folding techniques.

[0025] Figures 3 to 8 This is a side view showing the surface of various cell cells that can be included in a cell cell.

[0026] Figure 9 This diagram illustrates how the cell units can be arranged when the electrode assembly is unfolded, provided that there are six stacked cell units.

[0027] Figure 10 This diagram shows the possible arrangement of the cell units when the electrode assembly is deployed, with a total of seven stacked cell units.

[0028] Figure 11 This diagram shows the possible arrangement of the cell units when the electrode assembly is unfolded, with eight cells stacked together.

[0029] Figure 12 This diagram shows the possible arrangement of the cell units when the electrode assembly is unfolded, with nine cells stacked together.

[0030] Figure 13 This diagram shows the possible arrangement of the cell units when the electrode assembly is unfolded, assuming there are ten stacked cell units.

[0031] Figure 14 This diagram shows the possible arrangement of the cell units when the electrode assembly is unfolded, with eleven cells stacked together.

[0032] Figure 15 This diagram shows the possible arrangement of the cell units when the electrode assembly is unfolded, with a stack of twelve cell units. Detailed Implementation

[0033] In the following, preferred embodiments of the concepts of this disclosure will be described in detail with reference to the accompanying drawings. However, embodiments of the concepts of this disclosure may be modified in various other forms and should not be construed as limiting the scope of the concepts of this disclosure to the embodiments described below. Preferably, the concepts of embodiments of this disclosure are provided to provide a more comprehensive explanation of the concepts of this disclosure to those skilled in the art. The same reference numerals generally denote the same elements. Furthermore, various elements and areas in the drawings are depicted schematically. Therefore, the concepts of this disclosure are not limited to the relative dimensions or spacing depicted in the drawings.

[0034] Various components may be described using terms such as first, second, etc., but these components are not limited by these terms. These terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and vice versa, without departing from the scope of the concepts of this disclosure.

[0035] The terminology used in this application is intended only to describe particular embodiments and is not intended to limit the concepts of this disclosure. Singular expressions include plural forms unless the context clearly indicates otherwise. In this application, expressions such as “comprising” or “having” are intended to indicate the presence of features, counts, steps, operations, components, portions, or combinations thereof described herein, and should not be construed as excluding the possibility of the presence or addition of one or more other features, counts, operations, components, portions, or combinations thereof.

[0036] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which the concepts of this disclosure pertain. It should also be understood that terms such as those defined in commonly used dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the field to which they pertain, and shall not be interpreted as having an inappropriate formal meaning unless expressly defined herein.

[0037] When certain implementations are feasible in other ways, certain sequences of processes may be performed in a different order than they are described. For example, two processes described consecutively may be performed substantially simultaneously, or they may be performed in the reverse order of their description.

[0038] In the accompanying drawings, variations in the shapes shown can be anticipated, for example, depending on manufacturing techniques and / or tolerances. Therefore, embodiments of this disclosure should not be construed as limited to specific geometries of the areas shown herein, and should include variations in geometry, for example, due to manufacturing processes. All terms “and / or” as used herein include each and every combination of one or more components mentioned. Furthermore, the term “substrate” as used herein may refer to the substrate itself, or to a laminated structure comprising the substrate and any predetermined layers or films formed on its surface. Additionally, the term “surface of substrate” as used herein may refer to the exposed surface of the substrate itself, or the outer surface of a predetermined layer or film formed on the substrate.

[0039] Figure 1 This is an exploded perspective view of a secondary battery 10 according to one embodiment of the present disclosure.

[0040] Reference Figure 1 The secondary battery 10 includes an electrode assembly 12 to which electrode leads 11 are attached and a housing 13.

[0041] The housing 13 includes a storage portion 13a for storing the electrode assembly 12 and a sealing portion 13b formed to seal the electrode assembly 12. The sealing portion 13b may include a sealant resin, and the sealant resin may be fused along the outer peripheral surface of the storage portion 13a to seal the electrode assembly 12.

[0042] The housing 13 may be in the form of a multilayer film, comprising an outer layer for external impact protection, a moisture-repelling metal barrier layer, and a sealing layer for sealing the housing. The outer layer may include a polyethylene terephthalate (PET) film; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolyester, polycarbonate, nylon, or other polyester-based films, and may be single-layered or multi-layered. The metal barrier layer may include aluminum, copper, etc. The sealant layer may include a sealant resin, and may be single-layered or multi-layered. The sealant resin may include polypropylene (PP), acid-modified polypropylene (PPa), atactic polypropylene, ethylene-propylene copolymer, or two or more of the foregoing. The ethylene-propylene copolymer may include, but is not limited to, ethylene-propylene rubber, ethylene-propylene block copolymer, etc.

[0043] In some embodiments, housing 13 may be a pouch-type housing. If housing 13 is a pouch-type housing, housing 13 may include an upper pouch and a lower pouch. If housing 13 includes an upper pouch and a lower pouch, housing 13 may have a structure in which the upper pouch and the lower pouch are positioned such that the sealant resin is opposite to each other, and then the opposite sealant resin is fused together under heat and pressure to seal the battery.

[0044] The sealing portion 13b can be fused by thermal fusion, ultrasonic fusion, etc., but is not limited to these methods, as long as the sealing portion 13b can be fused. The sealing portion 13b can be a four-sided seal or a three-sided seal at the edge of the housing 13. The three-sided seal structure refers to the process of forming the upper bag and the lower bag into a single bag sheet, then bending the boundary between the upper bag and the lower bag to close the electrode assembly storage portion 13a formed in the upper bag and the lower bag, and sealing the edges of the other three sides except for the bent portion.

[0045] Electrode leads 11 may be stored within the housing 13, such that a portion of the electrode leads 11 is exposed to the outside of the housing 13. The secondary battery 10 may also include a lead film 14 on the electrode leads 11.

[0046] The lead film 14 is wound around a portion of the outer surface of the electrode lead 11 and inserted between the electrode lead 11 and the sealing portion 13b. The lead film 14 is inserted between the electrode lead 11 and the sealing portion 13b to facilitate the engagement of the electrode lead 11 and the sealing portion 13b.

[0047] However, the housing 13 disclosed herein is not limited to a pouch-type housing, and can be any housing suitable for manufacturing prismatic or cylindrical batteries.

[0048] The electrode assembly 12 includes a positive electrode, a negative electrode, and a separator. The electrode assembly 12 is a stacked and folded electrode assembly.

[0049] Figure 2 This is a conceptual diagram illustrating a method for manufacturing electrode assembly 12 in a stacked and folded manner.

[0050] Reference Figure 2 The electrode assembly 12 can be obtained by aligning and adhering the unit cell 121 to the folded diaphragm 122, and then folding the folded diaphragm 122 sequentially. This stacked and folded electrode assembly 12 has high stability because the movement of the unit cell 121 can be restricted by the folded diaphragm 122.

[0051] The cell 121 can be a single cell and / or a dual cell, and a pair of cell 121 can be adjacent to each other with a folded separator 122 between them. In adjacent cell pairs 121, the polarities of the electrodes facing each other and the folded separator 122 between them can be different.

[0052] Various types of cell cells can be used in cell cell 121.

[0053] Figures 3 to 8 This is a side view showing the surface of various cell cells that may be included in cell cell 121.

[0054] Reference Figure 3 The positive electrode AC is disposed on both sides of the negative electrode AA, and the separator AS is disposed between the negative electrode AA and the positive electrode AC. The negative electrode AA includes negative electrode active material layers located on both sides of the current collector, and the positive electrode AC includes positive electrode active material layers located on both sides of the current collector. This type of cell can be called Type A.

[0055] Reference Figure 4 The negative electrode CA is disposed on both sides of the positive electrode CC, and the separator CS is disposed between the positive electrode CC and the negative electrode CA. The negative electrode CA includes negative electrode active material layers located on both sides of the current collector, and the positive electrode CC includes positive electrode active material layers located on both sides of the current collector. This type of cell can be called a C-type cell.

[0056] Reference Figure 5 The positive electrode RC is located on one side of the negative electrode RA, and the single-sided positive electrode RSC is located on the other side of the negative electrode RA. The separator RS is located between the negative electrode RA and the positive electrode RC, and between the negative electrode RA and the single-sided positive electrode RSC. The negative electrode RA includes negative electrode active material layers located on both sides of the current collector, and the positive electrode RC includes positive electrode active material layers located on both sides of the current collector. The single-sided positive electrode RSC only includes a positive electrode active material layer on the side of the current collector facing the separator RS, and the tab of the single-sided positive electrode RSC is located on the right side. This type of cell can be called an R-type cell.

[0057] Reference Figure 6The positive electrode LC is located on one side of the negative electrode LA, and the single-sided positive electrode LSC is located on the other side of the negative electrode LA. The separator LS is located between the negative electrode LA and the positive electrode LC, and between the negative electrode LA and the single-sided positive electrode LSC. The negative electrode LA includes negative electrode active material layers on both sides of the current collector, and the positive electrode LC includes positive electrode active material layers on both sides of the current collector. The single-sided positive electrode LSC only includes a positive electrode active material layer on the side of the current collector facing the separator LS, and the tab of the single-sided positive electrode LSC is located on the left side. This type of cell can be called an L-type.

[0058] The aforementioned Type A, Type C, Type R, and Type L cell units are all dual-cell units.

[0059] Reference Figure 7 The negative electrode MRA can be disposed on one side of the separator MRS, and the positive electrode MRC can be disposed on the other side of the separator MRS, with the tab of the positive electrode MRC disposed on the right side. The negative electrode MRA includes negative electrode active material layers located on both sides of the current collector, and the positive electrode MRC includes positive electrode active material layers located on both sides of the current collector. This type of unit cell can be called MR type.

[0060] Reference Figure 8 The negative electrode MLA can be disposed on one side of the separator MLS, and the positive electrode MLC can be disposed on the other side of the separator MLS, with the tab of the positive electrode MLC located on the left side. The negative electrode MLA includes negative electrode active material layers located on both sides of the current collector, and the positive electrode MLC includes positive electrode active material layers located on both sides of the current collector. This type of cell can be referred to as ML type.

[0061] The MR and ML type cell cells mentioned above are both single cells.

[0062] The folded diaphragm 122 can be made of any porous polymer substrate conventionally used in the art, such as, but not limited to, polyolefin porous membranes or nonwoven fabrics.

[0063] Examples of polyolefin porous membranes include membranes formed from polyethylene (such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, and ultra-high molecular weight polyethylene) and polyolefin-based polymers (such as polypropylene, polybutene, and polypentene) (alone or mixtures thereof).

[0064] Besides polyolefin-based nonwovens, nonwovens can also include, for example, polyethylene terephthalate, polybutylene terephthalate, polyester, polyoxymethylene, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene ether, polyphenylene sulfide, and polyethylene naphthalate, which can be used alone or as mixtures of these polymers. The structure of nonwovens can be spunbond nonwovens or meltblown nonwovens composed of long fibers.

[0065] The thickness of the porous polymer substrate is not particularly limited, but can be from about 5 μm to about 50 μm. The pore size and porosity present in the porous polymer substrate are also not particularly limited, but can be from about 0.01 μm to about 50 μm and from about 10% to about 95%, respectively. Furthermore, in this case, the porous polymer substrate can be formed as a single layer, or it can be formed by laminating two or more layers.

[0066] Figures 3 to 8 The cell shown can be aligned and adhered to, for example, Figure 2 The folded separator 122 is shown in the diagram. In this case, the electrodes forming one surface of the cell 121 are adhered to the folded separator 122, while the electrodes forming the other surface of the cell 121 are not adhered to the folded separator 122. The electrodes not adhered to the folded separator 122 face the folded separator 122 after folding, but are not adhered to the folded separator 122.

[0067] When the electrode not adhered to the other surface of the folded separator 122 is a negative electrode, lithium tends to precipitate in a dendritic pattern during repeated charge and discharge cycles, which may be a factor limiting the life of the secondary battery. This is understandable because when the electrode not adhered to the folded separator 122 is a negative electrode, the unadhered surface has a stronger tendency to act as an interfacial diffusion barrier, which promotes chemical side reactions and accelerates electrolyte consumption.

[0068] Therefore, the inventors of this disclosure have found that it is important to reduce the number of cell 121, wherein the electrode not adhered to the exposed surface of the folded diaphragm 122 is the negative electrode.

[0069] However, it was found that when the number of stacked cell cells 121 is five or fewer, the number of cell cells 121 with exposed electrodes not adhered to the folded separator 122 remains constant, even when all possible arrangements of cell cells 121 are considered. Therefore, it was found that when the number of stacked cell cells 121 is five or fewer, it is difficult to minimize the number of cell cells 121 with exposed electrodes not adhered to the folded separator 122.

[0070] However, it has been found that when all possible arrangements of the cell 121 are considered, the number of cell 121 whose exposed electrodes not adhered to the folded diaphragm 122 are negative electrodes can be minimized when the number of stacked cell 121 is six or more.

[0071] When the number of stacked cell 121 is six, in Figure 9The diagram illustrates possible arrangements of cell 121 when the electrode assembly is deployed. Among these cases, the arrangement with RL-ML-MR-ML-C (i.e., case 2) minimizes the number of cell 121, where the exposed electrode not adhered to the folded diaphragm 122 is the negative electrode.

[0072] like Figure 2 As shown, the cell 121 at the beginning of the fold is the rightmost cell 121, and a blank area corresponding to the width of one cell 121 can be provided between two rightmost cell 121s. These rules can be applied even when the number of stacked cell 121s is greater than six.

[0073] Furthermore, the last two cell units 121 at the end of the fold are R-type and L-type. The R-type and L-type cell units 121 have positive electrodes as electrodes that are not adhered to the folded separator 122.

[0074] exist Figure 10 The diagram illustrates possible arrangements of the cell cells 121 when the electrode assembly is unfolded, with a total of seven stacked cell cells 121. Among these cases, the arrangement with RL-ML-MR-ML-MR-C (i.e., case 6) minimizes the number of cell cells 121, where the exposed electrode not adhered to the folded diaphragm 122 is the negative electrode.

[0075] exist Figure 11 The diagram illustrates the possible arrangements of the cell cells 121 when the electrode assembly is unfolded, assuming a stacked number of eight cell cells 121. In case 1, four cell cells 121 have negative electrodes exposed, while in other cases, three cell cells 121 have negative electrodes exposed. Therefore, when the stacked number of cell cells 121 is eight, any arrangement from case 2 to 5 can be used.

[0076] exist Figure 12 The diagram illustrates the possible arrangement of the cell 121 when the electrode assembly is unfolded, with nine stacked cell 121 units. The arrangement that minimizes the number of cell 121 units with the exposed negative electrode is one of the following three cases: RLC-MR-A-MR-CCA (Case 3); RL-ML-C-ML-ACCA (Case 5); RL-ML-C-ML-ML-ML-AC (Case 6).

[0077] exist Figure 13The diagram illustrates the arrangement of the cell cells 121 when the electrode assembly is unfolded, with ten cells stacked. Among these arrangements, the one with the RL-ML-C-ML-A-ML-CCA arrangement (i.e., case 8) minimizes the number of cell cells 121, where the exposed electrode not adhered to the folded diaphragm 122 is the negative electrode.

[0078] exist Figure 14 The diagram illustrates the possible arrangement of the cell 121 when the electrode assembly is unfolded, assuming an eleven-cell stack. The arrangement that minimizes the number of cell 121 with the exposed negative electrode is one of the following four cases: RLC-MR-A-MR-CCAAC (Case 5); RL-ML-C-ML-ACCCAAC (Case 6); RL-ML-C-ML-ML-ML-ACCA (Case 10); RLC-MR-MR-MR-A-MR-CCA (Case 11).

[0079] exist Figure 15 The diagram illustrates the possible arrangement of the cell 121 when the electrode assembly is deployed, assuming there are twelve cell 121 of a certain length. The arrangement that minimizes the number of cell 121 with the exposed negative electrode is one of the following two cases: RLC-MR-A-MR-C-MR-ACCA (Case 10); RL-ML-C-ML-A-ML-CCAAC (Case 11).

[0080] Those skilled in the art will be able to consider all possible cases, even when the number of stacked cell 121 is greater than thirteen, and find that the number of cell 121 with exposed negative electrodes is minimized according to the method described above.

[0081] The cell 121 may include at least one single cell. In some embodiments, the number of single cells may be less than half (1 / 2) of the total number of single cells 121.

[0082] By minimizing the number of cell cells 121 whose electrodes are negative on the exposed other surface of the folded separator 122, the secondary battery 10 according to embodiments of the present disclosure can suppress to a maximum extent the tendency for lithium to deposit in dendritic form during repeated charge and discharge cycles. This can help extend the life of the secondary battery.

[0083] While embodiments of this disclosure have been described in detail above, those skilled in the art to which this disclosure pertains will be able to make many modifications to this disclosure without departing from the spirit and scope of this disclosure as defined by the appended claims. Therefore, future modifications to this disclosure will not deviate from the technical scope of this disclosure.

[0084] <Explanation of Figure Markers>

[0085] 10: Secondary batteries

[0086] 11: Electrode leads

[0087] 12: Electrode assembly

[0088] 13: Shell

[0089] 13a: Electrode assembly storage section

[0090] 13b: Sealing part

[0091] 14: Lead wire film

[0092] 121: Cell Unit

[0093] 122: Folded diaphragm

Claims

1. A secondary battery, the secondary battery comprising: Electrode assemblies manufactured using a stacking and folding method; as well as A housing that accommodates the electrode assembly, wherein, The electrode assembly includes six or more cell units attached to a folded separator, wherein one surface of each of the six or more cell units is attached to the folded separator. The cell is arranged such that when the electrode assembly is unfolded, the number of negative electrodes forming other surfaces of the cell is minimized, and these other surfaces are not attached to the folded diaphragm.

2. The secondary battery according to claim 1, wherein, The outermost cell units on both sides of the electrode assembly each have a stacked structure of single-sided positive electrode / diaphragm / negative electrode / diaphragm / positive electrode.

3. The secondary battery according to claim 1, wherein, The electrode assembly is configured such that the electrodes of a pair of cell cells facing each other across the folded diaphragm have different polarities.

4. The secondary battery according to claim 1, wherein, The electrode assembly includes at least one single cell.

5. The secondary battery according to claim 1, wherein, The electrode assembly comprises eight or more individual cells, and the number of individual cells is less than half the total number of all individual cells.

6. The secondary battery according to claim 1, wherein, The electrode assembly is manufactured by arranging six or more cell units on the folded diaphragm and then folding the folded diaphragm by attaching one surface of the cell unit to the folded diaphragm.

7. The secondary battery according to claim 1, wherein, A cell with the positive electrode positioned on either side of the negative electrode and a separator positioned between the electrodes is defined as type A. A cell with the negative electrode positioned on both sides of the positive electrode and a separator positioned between the electrodes is defined as a C-type cell. A cell with a single-sided positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single-sided positive electrode located on the right side is defined as an R-type cell. A cell with a single positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single positive electrode located on the left side is defined as L-shaped. A cell with a negative and positive electrode respectively disposed on both sides of the diaphragm, and the positive electrode tab disposed on the right side, is defined as an MR type. A cell in which the negative and positive electrodes are respectively located on both sides of the diaphragm, and the tab of the positive electrode is located on the left side, is defined as type ML. The electrode assembly comprises twelve unit cells, and wherein, When the electrode assembly is deployed, the cell units are arranged in one of the following arrangements: RLC-MR-A-MR-C-MR-ACCA; RL-ML-C-ML-A-ML-CCAAC.

8. The secondary battery according to claim 1, wherein, A cell with the positive electrode positioned on either side of the negative electrode and a separator positioned between the electrodes is defined as type A. A cell with the negative electrode positioned on both sides of the positive electrode and a separator positioned between the electrodes is defined as a C-type cell. A cell with a single-sided positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single-sided positive electrode located on the right side is defined as an R-type cell. A cell with a single positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single positive electrode located on the left side is defined as L-shaped. A cell with a negative and positive electrode respectively disposed on both sides of the diaphragm, and the positive electrode tab disposed on the right side, is defined as an MR type. A cell in which the negative and positive electrodes are respectively located on both sides of the diaphragm, and the tab of the positive electrode is located on the left side, is defined as type ML. The electrode assembly comprises eleven unit cells, and wherein, When the electrode assembly is deployed, the cell units are arranged in one of the following arrangements: RLC-MR-A-MR-CCAAC; RL-ML-C-ML-ACCAAC; RL-ML-C-ML-ML-ML-ACCA; RLC-MR-MR-MR-A-MR-CCA.

9. The secondary battery according to claim 1, wherein, A cell with the positive electrode positioned on either side of the negative electrode and a separator positioned between the electrodes is defined as type A. A cell with the negative electrode positioned on both sides of the positive electrode and a separator positioned between the electrodes is defined as a C-type cell. A cell with a single-sided positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single-sided positive electrode located on the right side is defined as an R-type cell. A cell with a single positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single positive electrode located on the left side is defined as L-shaped. A cell with a negative and positive electrode respectively disposed on both sides of the diaphragm, and the positive electrode tab disposed on the right side, is defined as an MR type. The negative and positive electrodes are respectively disposed on both sides of the diaphragm, and the tab of the positive electrode is disposed on the left side. The unit cell is defined as type ML, wherein... The electrode assembly comprises eight unit cells, and wherein, When the electrode assembly is deployed, the cell units are arranged in one of the following arrangements: RL-ML-CCAAC; RLC-MR-ACCA; RLC-MR-MR-MR-AC; RL-ML-C-ML-ML-CA.

10. The secondary battery according to claim 1, wherein, A cell with the positive electrode positioned on either side of the negative electrode and a separator positioned between the electrodes is defined as type A. A cell with the negative electrode positioned on both sides of the positive electrode and a separator positioned between the electrodes is defined as a C-type cell. A single-sided positive electrode and a positive electrode are respectively disposed on both sides of the negative electrode, a diaphragm is disposed between the electrodes, and the tab of the single-sided positive electrode is disposed on the right side of the unit cell, which is defined as R-type. A single-sided positive electrode and a positive electrode are respectively disposed on both sides of the negative electrode, a diaphragm is disposed between the electrodes, and the tab of the single-sided positive electrode is disposed on the left side of the unit cell, which is defined as L-shaped. A cell with a negative and positive electrode respectively disposed on both sides of the diaphragm, and the positive electrode tab disposed on the right side, is defined as an MR type. A cell in which the negative and positive electrodes are respectively located on both sides of the diaphragm, and the tab of the positive electrode is located on the left side, is defined as type ML. The electrode assembly comprises ten unit cells, and wherein, When the electrode assembly is deployed, the cell units are arranged in the following order: RL-ML-C-ML-A-ML-CCA.

11. The secondary battery according to claim 1, wherein, A cell with the positive electrode positioned on either side of the negative electrode and a separator positioned between the electrodes is defined as type A. A cell with the negative electrode positioned on both sides of the positive electrode and a separator positioned between the electrodes is defined as a C-type cell. A cell with a single-sided positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single-sided positive electrode located on the right side is defined as an R-type cell. A cell with a single positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single positive electrode located on the left side is defined as L-shaped. A cell with a negative and positive electrode respectively disposed on both sides of the diaphragm, and the positive electrode tab disposed on the right side, is defined as an MR type. A cell in which the negative and positive electrodes are respectively located on both sides of the diaphragm, and the tab of the positive electrode is located on the left side, is defined as type ML. The electrode assembly comprises nine unit cells, and among them, When the electrode assembly is deployed, the cell units are arranged in one of the following arrangements: RLC-MR-A-MR-CCA; RL-ML-C-ML-ACCA; RL-ML-C-ML-ML-ML-AC.

12. The secondary battery according to claim 1, wherein, A cell with the positive electrode positioned on either side of the negative electrode and a separator positioned between the electrodes is defined as type A. A cell with the negative electrode positioned on both sides of the positive electrode and a separator positioned between the electrodes is defined as a C-type cell. A cell with a single-sided positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single-sided positive electrode located on the right side is defined as an R-type cell. A cell with a single positive electrode and a positive electrode respectively located on opposite sides of the negative electrode, a diaphragm located between the electrodes, and the tab of the single positive electrode located on the left side is defined as L-shaped. A cell with a negative and positive electrode respectively disposed on both sides of the diaphragm, and the positive electrode tab disposed on the right side, is defined as an MR type. A cell in which the negative and positive electrodes are respectively located on both sides of the diaphragm, and the tab of the positive electrode is located on the left side, is defined as type ML. The electrode assembly comprises seven unit cells, and wherein, When the electrode assembly is deployed, the cell units are arranged in the following order: RL-ML-MR-ML-MR-C.

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