Secondary battery

Abstract

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

Description

secondary batteries

[0001] The present invention relates to a secondary battery, and more specifically, to a secondary battery with an extended lifespan.

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

[0003] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. They are widely used in electronic devices such as mobile phones, laptops, and camcorders, as well as electric vehicles. In particular, lithium secondary batteries have a higher capacity than nickel-cadmium or nickel-hydrogen batteries and a higher energy density per unit weight, leading to a rapid increase in their use.

[0004] Various structures and / or manufacturing methods are being proposed and applied to manufacture secondary batteries, and various efforts are being made to extend the life of secondary batteries.

[0005] The technical problem to be achieved by the present invention is to provide a secondary battery with an extended lifespan.

[0006] The present invention provides a secondary battery comprising an electrode assembly manufactured by a stack-and-fold method to achieve the above technical problem; and a case accommodating the electrode assembly, wherein the electrode assembly comprises six or more unit cells bonded to a folded separator, each of the six or more unit cells having one surface bonded to the folding separator, and the unit cells are arranged so that, when the electrode assembly is unfolded, the number of negative electrodes among the electrodes on the other surfaces of the unit cells that are not bonded to the folding separator is minimized.

[0007] In some embodiments, the outermost unit cells on both sides of the electrode assembly may each have a stacked structure of single anode / separator / cathode / separator / anode.

[0008] In some embodiments, the electrode assembly may be configured such that the polarities of the electrodes of a pair of unit cells facing each other with the folding separator interposed therebetween are different from each other.

[0009] In some embodiments, the electrode assembly may include at least one monocell.

[0010] In some embodiments, the electrode assembly comprises eight or more unit cells, and the number of monocells may be less than half the total number of unit cells.

[0011] In some embodiments, the electrode assembly may be an electrode assembly manufactured by arranging six or more unit cells on a folding separator, then adhering one surface of the unit cells to the folding separator, and folding the same.

[0012] In some embodiments, a unit cell in which a cathode is provided on each side of a cathode and a separator is disposed between the electrodes may be defined as an A-type, a unit cell in which a cathode is provided on each side of a cathode and a separator is disposed between the electrodes may be defined as a C-type, a unit cell in which a single cathode and an anode are provided on each side of a cathode and a separator is disposed between the electrodes, and a tab of the single anode is disposed on the right may be defined as an R-type, a unit cell in which a single anode and an anode are provided on each side of a cathode and a separator is disposed between the electrodes, and a tab of the single anode is disposed on the left may be defined as an L-type, a unit cell in which a cathode and an anode are provided on each side of a separator and a tab of the anode is disposed on the right may be defined as an MR-type, and a unit cell in which a cathode and an anode are provided on each side of a separator and a tab of the anode is disposed on the left may be defined as an ML-type.

[0013] In some embodiments, the electrode assembly is composed of 12 unit cells, and when the electrode assembly is deployed, the arrangement of the unit cells may be one of the following arrangements:

[0014] RLC-MR-A-MR-C-MR-ACCA;

[0015] RL-ML-C-ML-A-ML-CCAAC.

[0016] In some embodiments, the electrode assembly is composed of 11 unit cells, and when the electrode assembly is deployed, the arrangement of the unit cells may be one of the following arrangements:

[0017] RLC-MR-A-MR-CCAAC;

[0018] RL-ML-C-ML-ACCAAC;

[0019] RL-ML-C-ML-ML-ML-ACCA;

[0020] RLC-MR-MR-MR-A-MR-CCA.

[0021] In some embodiments, the electrode assembly may be composed of 10 unit cells, and when the electrode assembly is unfolded, the unit cells may be arranged in the order of RL-ML-C-ML-A-ML-CCA.

[0022] In some embodiments, the electrode assembly is composed of nine unit cells, and when the electrode assembly is deployed, the arrangement of the unit cells may be one of the following arrangements:

[0023] RLC-MR-A-MR-CCA;

[0024] RL-ML-C-ML-ACCA;

[0025] RL-ML-C-ML-ML-ML-AC.

[0026] In some embodiments, the electrode assembly may be composed of seven unit cells, and when the electrode assembly is unfolded, the unit cells may be arranged in the order of RL-ML-MR-ML-MR-C.

[0027] The secondary battery of the present invention has the effect of extending the life of the secondary battery by maximally suppressing lithium from being precipitated in a fingerprint shape in a secondary battery manufactured by a stack-and-folding method.

[0028] 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.

[0029] Figure 1 is an exploded perspective view showing a secondary battery according to one embodiment of the present invention.

[0030] Figure 2 is a conceptual diagram illustrating a method for manufacturing an electrode assembly using a stack-and-fold method.

[0031] Figures 3 to 8 are side views showing the sides of various unit cells that can be included in the unit cell.

[0032] Figure 9 is an image showing the number of cases in which unit cells can be arranged when the electrode assembly is unfolded when the number of stacked unit cells is 6.

[0033] Figure 10 is an image showing the number of cases in which unit cells can be arranged when the electrode assembly is unfolded when the number of stacked unit cells is 7.

[0034] Figure 11 is an image showing the number of cases in which unit cells can be arranged when the electrode assembly is unfolded when the number of stacked unit cells is 8.

[0035] Figure 12 is an image showing the number of cases in which unit cells can be arranged when the electrode assembly is unfolded when the number of stacked unit cells is 9.

[0036] Figure 13 is an image showing the number of cases in which unit cells can be arranged when the electrode assembly is unfolded when the number of stacked unit cells is 10.

[0037] Figure 14 is an image showing the number of cases in which unit cells can be arranged when the electrode assembly is unfolded when the number of stacked unit cells is 11.

[0038] Figure 15 is an image showing the number of cases in which unit cells can be arranged when the electrode assembly is unfolded when the number of stacked unit cells is 12.

[0039] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments of the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. It is preferable to interpret that the embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art. Like numbers refer to like elements throughout. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the present invention is not limited by the relative sizes or intervals depicted in the accompanying drawings.

[0040] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, a first component could be referred to as a "second component," and vice versa, without departing from the scope of the present invention.

[0041] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the inventive concept. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the expressions "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, operations, components, parts, or combinations thereof.

[0042] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, it is to be understood that commonly used terms, such as those defined in dictionaries, should be interpreted to have a meaning consistent with their meaning within the relevant technical context, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0043] In some embodiments, where implementations are otherwise feasible, specific process sequences may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0044] In the accompanying drawings, variations in the shapes depicted may be expected, for example, depending on manufacturing techniques and / or tolerances. Therefore, embodiments of the present invention should not be construed as being limited to the specific shapes of the regions depicted herein, but should include, for example, changes in shapes resulting from the manufacturing process. All terms "and / or" used herein include each and every combination of one or more of the mentioned components. In addition, the term "substrate" used herein may mean the substrate itself, or a laminated structure including the substrate and a predetermined layer or film formed on the surface thereof. In addition, the "surface of the substrate" in this specification may mean the exposed surface of the substrate itself, or the outer surface of a predetermined layer or film formed on the substrate.

[0045]

[0046] Figure 1 is an exploded perspective view showing a secondary battery (10) according to one embodiment of the present invention.

[0047] Referring to Fig. 1, the secondary battery (10) includes an electrode assembly (12) to which an electrode lead (11) is attached and a case (13).

[0048] The case (13) above has a storage portion (13a) for storing an electrode assembly (12), and a sealing portion (13b) formed to seal the electrode assembly (12). The sealing portion (13b) includes a sealant resin, and the sealant resin can be fused along the outer circumferential surface of the storage portion (13a) to seal the electrode assembly (12).

[0049] The case (13) may be provided in the form of a multi-layer film structure including an outer layer for external impact protection, a metal barrier layer for blocking moisture, and a sealant layer for sealing the case. The outer layer may include poly(ethylene terephthalate) (PET), polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, polycarbonate, nylon, or other polyester-based films, and may be configured as a single layer or multiple layers. The metal barrier layer may include aluminum, copper, or the like. The sealant layer may include a sealant resin, and may be configured as a single layer or multiple layers. The sealant resin may include polypropylene (PP), acid modified polypropylene (PPa), random polypropylene, an ethylene propylene copolymer, or two or more thereof. The above ethylene propylene copolymer may include, but is not limited to, ethylene-propylene rubber, ethylene-propylene block copolymer, etc.

[0050] In some embodiments, the case (13) may be a pouch case. When the case (13) is a pouch case, the case (13) may include an upper pouch and a lower pouch. When the case (13) includes an upper pouch and a lower pouch, the upper pouch and the lower pouch may be arranged so that the sealant resins face each other, and then the opposing sealant resins may be fused together by heat and pressure to have a structure that seals the battery.

[0051] The fusion of the above sealing portion (13b) may be thermal fusion, ultrasonic fusion, etc., but is not particularly limited as long as the sealing portion (13b) can be fused. The sealing portion (13b) may be four-sided or three-sided sealed at the edge of the case (13). The three-sided sealing structure means a structure in which the upper pouch and the lower pouch are formed into one pouch sheet, and then the boundary surfaces of the upper and lower pouches are folded so that the electrode assembly receiving portions (13a) formed in the upper and lower pouches are overlapped, and the edges of the remaining three sides, excluding the folded portion, are sealed.

[0052] The electrode lead (11) may be housed within the case (13) so that a portion thereof is exposed to the outside of the case (13). The secondary battery (10) may further include a lead film (14) on the electrode lead (11).

[0053] The above lead film (14) wraps a portion of the outer surface of the electrode lead (11) and is interposed between the electrode lead (11) and the sealing portion (13b). The above lead film (14) is interposed between the electrode lead (11) and the sealing portion (13b) to help fasten the electrode lead (11) and the sealing portion (13b).

[0054] However, the case (13) of the present invention is not limited to a pouch case, and any case suitable for manufacturing a square battery or a cylindrical battery may be employed.

[0055] The above electrode assembly (12) includes an anode, a cathode, and a separator. The above electrode assembly (12) is a stack and folding type electrode assembly.

[0056] Figure 2 is a conceptual diagram showing a method for manufacturing an electrode assembly (12) using a stack and folding method.

[0057] Referring to Fig. 2, the unit cells (121) are aligned and adhered on a folding separator (122), and then the folding separator (122) is continuously folded (folded) to obtain an electrode assembly (122). This stack-and-fold electrode assembly (12) has high stability because the movement of the unit cells (121) can be restricted by the folding separator (122).

[0058] The above unit cell (121) may be a monocell and / or a bicell, and a pair of unit cells (121) may be adjacent to each other with the folding separator (122) interposed therebetween. At this time, in the adjacent pair of unit cells (121), the polarities of the electrodes facing each other with the folding separator (122) interposed therebetween may be different from each other.

[0059]

[0060] The above unit cell (121) can employ various types of unit cells.

[0061] Figures 3 to 8 are side views showing the sides of various unit cells that can be included in the unit cell (121).

[0062] Referring to Fig. 3, a positive electrode (AC) is provided on each side of a negative electrode (AA), and a separator (AS) is provided between the negative electrode (AA) and the positive electrode (AC). The negative electrode (AA) includes a negative electrode active material layer on both sides of the current collector, and the positive electrode (AC) includes a positive electrode active material layer on both sides of the current collector. A unit cell of this type may be referred to as an A-type.

[0063] Referring to Fig. 4, a negative electrode (CA) is provided on each side of a positive electrode (CC), and a separator (CS) is provided between the positive electrode (CC) and the negative electrode (CA). The negative electrode (CA) includes a negative electrode active material layer on both sides of the current collector, and the positive electrode (CC) includes a positive electrode active material layer on both sides of the current collector. A unit cell of this type may be referred to as a C-type.

[0064] Referring to Fig. 5, a positive electrode (RC) is provided on one side of a negative electrode (RA), and a single positive electrode (RSC) is provided on the other side. A separator (RS) is provided between the negative electrode (RA) and the positive electrode (RC) and between the negative electrode (RA) and the single positive electrode (RSC). The negative electrode (RA) includes a negative electrode active material layer on both sides of a current collector, and the positive electrode (RC) includes a positive electrode active material layer on both sides of a current collector. In addition, the single positive electrode (RSC) includes a positive electrode active material layer only on one side of the current collector facing the separator (RS), and the tab of the single positive electrode (RSC) is arranged on the right side. A unit cell of this type may be referred to as an R-type.

[0065] Referring to Fig. 6, a positive electrode (LC) is provided on one side of a negative electrode (LA), and a single positive electrode (LSC) is provided on the other side. A separator (LS) is provided between the negative electrode (LA) and the positive electrode (LC) and between the negative electrode (LA) and the single positive electrode (LSC). The negative electrode (LA) includes a negative electrode active material layer on both sides of a current collector, and the positive electrode (LC) includes a positive electrode active material layer on both sides of a current collector. In addition, the single positive electrode (LSC) includes a positive electrode active material layer only on one side of the current collector facing the separator (LS), and the tab of the single positive electrode (LSC) is arranged on the left side. A unit cell of this form may be referred to as an L-type.

[0066] The A-type, C-type, R-type, and L-type unit cells described above are all bicelles.

[0067] Referring to Fig. 7, a negative electrode (MRA) and a positive electrode (MRC) are provided on both sides of a separator (MRS), and the tab of the positive electrode (MRC) may be positioned on the right side. The negative electrode (MRA) includes a negative electrode active material layer on both sides of the current collector, and the positive electrode (MRC) includes a positive electrode active material layer on both sides of the current collector. A unit cell of this type may be referred to as an MR-type.

[0068] Referring to Fig. 8, a negative electrode (MLA) and a positive electrode (MLC) are provided on both sides of a separator (MLS), and the tab of the positive electrode (MLC) may be positioned on the right side. The negative electrode (MLA) includes a negative electrode active material layer on both sides of the current collector, and the positive electrode (MLC) includes a positive electrode active material layer on both sides of the current collector. A unit cell of this type may be referred to as an ML-type.

[0069] The MR-type and ML-type unit cells described above are all monocells.

[0070]

[0071] The above folding separator (122) can be used with any porous polymer substrate commonly used in the field, and for example, a polyolefin porous membrane or non-woven fabric can be used, but is not particularly limited thereto.

[0072] Examples of the above polyolefin porous membrane include a membrane formed from a single or mixed polymer of polyolefin polymers such as polyethylene, polypropylene, polybutylene, polypentene, etc., such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, and ultra-high molecular weight polyethylene.

[0073] The above nonwoven fabric may include, in addition to polyolefin-based nonwoven fabrics, nonwoven fabrics formed from polymers such as polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, and polyethylenenaphthalate, either singly or in combination. The structure of the nonwoven fabric may be a spunbond nonwoven fabric composed of long fibers or a meltblown nonwoven fabric.

[0074] The thickness of the porous polymer substrate is not particularly limited, but may be about 5 ㎛ to about 50 ㎛, and the pore size and pore content present in the porous polymer substrate are also not particularly limited, but may be about 0.01 ㎛ to about 50 ㎛ and about 10% to about 95%, respectively. In this case, the porous polymer substrate may be formed as a single layer or formed by stacking two or more layers.

[0075]

[0076] The unit cells illustrated in FIGS. 3 to 8 can be aligned and adhered to the folding separator (122) as illustrated in FIG. 2. At this time, the electrode forming one surface of the unit cell (121) is adhered to the folding separator (122), and the electrode forming the other surface of the unit cell (121) is not adhered to the folding separator (122). The electrode not adhered to the folding separator (122) faces the folding separator (122) after folding, but is not adhered to the folding separator (122).

[0077] If the electrode on the other surface that is not bonded to the folding separator (122) is a negative electrode, lithium tends to precipitate in the shape of a fingerprint as the charge / discharge cycle is repeated, which may be one cause of limiting the life of the secondary battery. This is understood to be because, when the electrode that is not bonded to the folding separator (122) is a negative electrode, the non-bonded surface tends to act as an interfacial diffusion resistance, promoting chemical side reactions and accelerating electrolyte consumption.

[0078] Accordingly, the inventor of the present invention found that it is important to reduce the number of unit cells (121) in which the electrode on the exposed other surface that is not bonded to the folding separator (122) is a cathode.

[0079] However, when the number of stacked unit cells (121) is 5 or less, it was found that the number of unit cells (121) whose exposed electrode that is not bonded to the folding separator (122) is the cathode is constant even when all possible arrangements of the unit cells (121) are considered. Therefore, when the number of stacked unit cells (121) is 5 or less, it was found that it is difficult to minimize the number of unit cells (121) whose exposed electrode that is not bonded to the folding separator (122) is the cathode.

[0080] However, when the number of stacked unit cells (121) is 6 or more, it was found that when considering all possible arrangements of the unit cells (121), there exists a case where the number of unit cells (121) in which the exposed electrode that is not bonded to the folding separator (122) is the cathode is minimized.

[0081]

[0082] When the number of stacked unit cells (121) is 6, the number of cases in which the unit cells (121) can be arranged when the electrode assembly is unfolded is as shown in Fig. 9. Among these, the case having the arrangement of RL-ML-MR-ML-C (i.e., Case 2) is the case in which the number of unit cells (121) in which the exposed electrode that is not bonded to the folding separator (122) is the negative electrode is minimized.

[0083] As shown in Fig. 2, the unit cell (121) where folding begins is the unit cell (121) arranged on the far right, and a blank area corresponding to the width of one unit cell (121) can be arranged between the two unit cells (121) arranged on the far right. This rule can also be applied when the number of stacked unit cells (121) is greater than six.

[0084] Furthermore, the last two unit cells (121) where folding is completed are R-type and L-type. The R-type and L-type unit cells (121) have an electrode that is not bonded to the folding separator (122) as the positive electrode.

[0085]

[0086] When the number of stacked unit cells (121) is 7, the cases in which the unit cells (121) can be arranged when the electrode assembly is unfolded are as shown in Fig. 10. Among these, the case having the arrangement of RL-ML-MR-ML-MR-C (i.e., Case 6) is the case in which the number of unit cells (121) in which the exposed electrode that is not bonded to the folding separator (122) is the negative electrode is minimized.

[0087]

[0088] When the number of stacked unit cells (121) is 8, the cases in which the unit cells (121) can be arranged when the electrode assembly is unfolded are as shown in FIG. 11. Among these, Case 1 has 4 unit cells (121) whose exposed electrode is the cathode, and in the other cases, the number of unit cells (121) whose exposed electrode is the cathode is 3. Therefore, when the number of stacked unit cells (121) is 8, any one arrangement from Case 2 to Case 5 can be adopted.

[0089]

[0090] When the number of stacked unit cells (121) is 9, the cases in which the unit cells (121) can be arranged when the electrode assembly is unfolded are as shown in Fig. 12. Among these, the case in which the number of unit cells (121) in which the exposed electrode is the cathode is minimized is one of the following three cases:

[0091] RLC-MR-A-MR-CCA (Case 3);

[0092] RL-ML-C-ML-ACCA (Case 5);

[0093] RL-ML-C-ML-ML-ML-AC (Case 6).

[0094]

[0095] When the number of stacked unit cells (121) is 10, the cases in which the unit cells (121) can be arranged when the electrode assembly is unfolded are as shown in FIG. 13. Among these, the case having the arrangement of RL-ML-C-ML-A-ML-CCA (i.e., Case 8) is the case in which the number of unit cells (121) in which the exposed electrode that is not bonded to the folding separator (122) is the negative electrode is minimized.

[0096]

[0097] When the number of stacked unit cells (121) is 11, the cases in which the unit cells (121) can be arranged when the electrode assembly is unfolded are as shown in Fig. 14. Among these, the case in which the number of unit cells (121) in which the exposed electrode is the cathode is minimized is one of the following four cases:

[0098] RLC-MR-A-MR-CCAAC (Case 5);

[0099] RL-ML-C-ML-ACCAAC (Case 6);

[0100] RL-ML-C-ML-ML-ML-ACCA (Case 10);

[0101] RLC-MR-MR-MR-A-MR-CCA (Case 11).

[0102]

[0103] When the number of stacked unit cells (121) is 12, the cases in which the unit cells (121) can be arranged when the electrode assembly is unfolded are as shown in Fig. 15. Among these, the case in which the number of unit cells (121) in which the exposed electrode is the cathode is minimized is one of the following two cases:

[0104] RLC-MR-A-MR-C-MR-ACCA (Case 10);

[0105] RL-ML-C-ML-A-ML-CCAAC (Case 11).

[0106]

[0107] A person skilled in the art will be able to consider all possible cases in which the number of stacked unit cells (121) is 13 or more according to the method described above, and will be able to find the case(s) that minimizes the number of unit cells (121) in which the exposed electrode is the cathode.

[0108]

[0109] The above unit cells (121) may include at least one monocell. In some embodiments, the number of monocells may be less than half (1 / 2) of the total number of unit cells (121).

[0110]

[0111] The secondary battery (10) according to embodiments of the present invention can minimize the number of unit cells (121) in which the electrode on the exposed other surface that is not bonded to the folding separator (122) is a cathode, thereby maximally suppressing the tendency for lithium to precipitate in the form of a fingerprint as the charge / discharge cycle is repeated. This can contribute to extending the life of the secondary battery.

[0112]

[0113] While the embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims. Therefore, modifications to future embodiments of the present invention will not depart from the scope of the invention.

[0114] <Explanation of symbols>

[0115] 10: Secondary batteries

[0116] 11: Electrode leads

[0117] 12: Electrode assembly

[0118] 13: Case

[0119] 13a: Electrode assembly storage compartment

[0120] 13b: Sealing part

[0121] 14: Lead Film

[0122] 121: Unit cell

[0123] 122: Folding separator

Claims

1. An electrode assembly manufactured by stacking and folding; and A case accommodating the electrode assembly; As a secondary battery including: The electrode assembly comprises six or more unit cells bonded to a folded separator, each of the six or more unit cells having one surface bonded to the folded separator, A secondary battery characterized in that the unit cells are arranged so that the number of negative electrodes among the electrodes on the other surfaces of the unit cells that are not bonded to the folding separator when the electrode assembly is unfolded is minimized.

2. In paragraph 1, A secondary battery characterized in that the outermost unit cells on both sides of the electrode assembly each have a stacked structure of single anode / separator / cathode / separator / anode.

3. In paragraph 1, A secondary battery characterized in that the electrode assembly is configured such that the polarities of the electrodes of a pair of unit cells facing each other with the folding separator interposed therebetween are different from each other.

4. In paragraph 1, A secondary battery, characterized in that the electrode assembly comprises at least one monocell.

5. In paragraph 1, A secondary battery characterized in that the electrode assembly includes eight or more unit cells, and the number of monocells is less than half of the total number of unit cells.

6. In paragraph 1, A secondary battery characterized in that the electrode assembly is an electrode assembly manufactured by arranging six or more unit cells on a folding separator, adhering one surface of the unit cells to the folding separator, and folding the same.

7. In paragraph 1, A unit cell that is provided with an anode on each side of the cathode and includes a separator between the electrodes is defined as A-type, A unit cell provided with a cathode on each side of the anode and including a separator between the electrodes is defined as a C-type. A unit cell in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the right side is defined as an R-type. A unit cell is defined as an L-type in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the left side. A unit cell in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the right side is defined as an MR-type. When a unit cell is defined as ML-type, in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the left side, A secondary battery characterized in that the electrode assembly is composed of 12 unit cells, and when the electrode assembly is unfolded, the arrangement of the unit cells is one of the following arrangements: RLC-MR-A-MR-C-MR-ACCA; RL-ML-C-ML-A-ML-CCAAC.

8. In paragraph 1, A unit cell that is provided with an anode on each side of the cathode and includes a separator between the electrodes is defined as A-type, A unit cell provided with a cathode on each side of the anode and including a separator between the electrodes is defined as a C-type. A unit cell in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the right side is defined as an R-type. A unit cell is defined as an L-type in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the left side. A unit cell in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the right side is defined as an MR-type. When a unit cell is defined as ML-type, in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the left side, A secondary battery characterized in that the electrode assembly is composed of 11 unit cells, and when the electrode assembly is unfolded, the arrangement of the unit cells is 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. In paragraph 1, A unit cell that is provided with an anode on each side of the cathode and includes a separator between the electrodes is defined as A-type, A unit cell provided with a cathode on each side of the anode and including a separator between the electrodes is defined as a C-type. A unit cell in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the right side is defined as an R-type. A unit cell is defined as an L-type in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the left side. A unit cell in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the right side is defined as an MR-type. When a unit cell is defined as ML-type, in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the left side, A secondary battery characterized in that the electrode assembly is composed of eight unit cells, and when the electrode assembly is unfolded, the arrangement of the unit cells is one of the following arrangements: RL-ML-CCAAC; RLC-MR-ACCA; RLC-MR-MR-MR-AC; RL-ML-C-ML-ML-CA.

10. In paragraph 1, A unit cell that is provided with an anode on each side of the cathode and includes a separator between the electrodes is defined as A-type, A unit cell provided with a cathode on each side of the anode and including a separator between the electrodes is defined as a C-type. A unit cell in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the right side is defined as an R-type. A unit cell is defined as an L-type in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the left side. A unit cell in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the right side is defined as an MR-type. When a unit cell is defined as ML-type, in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the left side, A secondary battery characterized in that the electrode assembly is composed of 10 unit cells, and when the electrode assembly is unfolded, the unit cells are arranged in the order of RL-ML-C-ML-A-ML-CCA.

11. In paragraph 1, A unit cell that is provided with an anode on each side of the cathode and includes a separator between the electrodes is defined as A-type, A unit cell provided with a cathode on each side of the anode and including a separator between the electrodes is defined as a C-type. A unit cell in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the right side is defined as an R-type. A unit cell is defined as an L-type in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the left side. A unit cell in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the right side is defined as an MR-type. When a unit cell is defined as ML-type, in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the left side, A secondary battery characterized in that the electrode assembly is composed of nine unit cells, and when the electrode assembly is unfolded, the arrangement of the unit cells is one of the following arrangements: RLC-MR-A-MR-CCA; RL-ML-C-ML-ACCA; RL-ML-C-ML-ML-ML-AC.

12. In paragraph 1, A unit cell that is provided with an anode on each side of the cathode and includes a separator between the electrodes is defined as A-type, A unit cell provided with a cathode on each side of the anode and including a separator between the electrodes is defined as a C-type. A unit cell in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the right side is defined as an R-type. A unit cell is defined as an L-type in which a single anode and a cathode are provided on each side of the cathode and a separator is included between the electrodes, and the tab of the single anode is placed on the left side. A unit cell in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the right side is defined as an MR-type. When a unit cell is defined as ML-type, in which a cathode and an anode are provided on both sides of the separator, and the tab of the anode is placed on the left side, A secondary battery characterized in that the electrode assembly is composed of seven unit cells, and when the electrode assembly is unfolded, the unit cells are arranged in the order of RL-ML-MR-ML-MR-C.

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