Secondary battery

Abstract

In order to improve the energy density of a secondary battery, minimize the likelihood of fires and explosions, and minimize dendritic crystal formation problems, a secondary battery is provided that includes a cathode material and an anode material, in which the anode material includes an anode structure, the anode structure is a sheet in which a plurality of yarns formed of carbon nanotube (CNT) fibers are woven.

Description

Technical Field

[0001] Exemplary embodiments relate to a secondary battery. Background Art

[0002] As the supply of electric vehicles using secondary batteries as a raw material for mileage expands and the demand for electric vehicles increases, interest in secondary batteries mounted on electric vehicles is also increasing.

[0003] The capacity of a secondary battery is directly related to the operating time of a target device (eg, the mileage of an electric vehicle). At the same time, the problem of increasing the volume and weight of the target device must also be considered, and thus the demand for secondary batteries with high energy density is quite high.

[0004] Furthermore, there is a significant demand for secondary batteries having high stability by minimizing the possibility of fire and explosion.

[0005] As a way to realize secondary batteries with high capacity and high stability, research on solid-state batteries is active. Summary of the invention Technical issues

[0006] In a solid-state battery, the battery's electrolyte, which is composed of a liquid electrolyte, is replaced by a solid electrolyte. When a solid electrolyte is used instead of a liquid electrolyte, the battery can be miniaturized because there is no risk of electrolyte leakage and a separator is not required to prevent contact between the positive and negative electrodes.

[0007] However, during repeated charging processes, dendrites (lithium metal crystals) are generated due to charge imbalance and uneven interface contraction occurring at the interface between the electrode and the electrolyte, and thus solid-state batteries have problems causing electrode short circuits and rapid performance degradation. Solutions to the problem

[0008] One or more embodiments of the present disclosure solve various technical problems in the related art, including the problems identified above.

[0009] One aspect provides a secondary battery having high energy density.

[0010] Another aspect also provides a secondary battery that minimizes the possibility of fire and explosion.

[0011] Furthermore, another aspect provides a secondary battery that minimizes a dendrite formation problem that occurs in the case of implementing a solid-state battery.

[0012] According to one aspect, there is provided a secondary battery including a cathode material and an anode material, wherein the anode material includes an anode structure which is a sheet in which a plurality of yarns formed of carbon nanotube (CNT) fibers are woven.

[0013] According to another aspect, the anode structure may be an anode current collector of a lithium ion battery.

[0014] According to one aspect, there is provided an anode-less secondary battery including a cathode material, an electrolyte, and an anode structure which is a sheet in which a plurality of yarns formed of CNT fibers contained in the electrolyte are woven.

[0015] According to another aspect, the electrolyte can be a solid.

[0016] Additional aspects of exemplary embodiments will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. Advantageous Effects of the Invention

[0017] According to the exemplary embodiment, the energy density of the secondary battery may be improved.

[0018] Furthermore, according to the exemplary embodiments, the possibility of fire and explosion of the secondary battery may be minimized.

[0019] Furthermore, according to the exemplary embodiments, the dendrite formation problem occurring in the case of realizing a solid-state battery may be minimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] These and / or other aspects, features and advantages of the present disclosure will become apparent and more readily understood from the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0021] Figure 1 This is a conceptual diagram of an existing lithium-ion battery;

[0022] Figure 2 and Figure 3 Schematically illustrating a CNT-based sheet relevant to the present disclosure;

[0023] Figure 4 is a partial front view of an anode structure according to an exemplary embodiment of the present disclosure;

[0024] Figure 5 is a partial perspective view of an anode structure according to another exemplary embodiment of the present disclosure;

[0025] Figure 6 A conceptual diagram of a secondary battery using an anode structure;

[0026] Fig. 7A and Figure 7B shows photographs of twisted yarns and braided yarns according to exemplary embodiments of the present disclosure;

[0027] FIG. 8A to FIG. 8D shows a process of forming an anode structure according to an exemplary embodiment of the present disclosure;

[0028] 9A to 9D A graph showing mechanical properties according to the type of yarn constituting the anode structure;

[0029] Fig.10 shows graphs showing electrical characteristics when the anode structure is formed of twisted yarn and when the anode structure is formed of braided yarn;

[0030] Fig.11 shows a graph showing the linear density when the anode structure is formed of twisted yarns and when it is formed of braided yarns; and

[0031] Fig.12 and Fig.13 Conceptual diagrams before and after lithium precipitation of an anode-less secondary battery and a solid-state battery related to the present disclosure are shown. DETAILED DESCRIPTION

[0032] The terms used in the exemplary embodiments are selected from currently widely used general terms as much as possible while considering the functions in the present disclosure. However, the terms can be changed according to the intentions of those skilled in the art or precedents, the emergence of new technologies, etc. In addition, in some cases, there are also terms selected by the applicant, and in these cases, the meaning will be described in detail in the corresponding description. Therefore, the terms used in the present disclosure should be defined based on the meaning of the terms and the content of the present disclosure, rather than the simple names of the terms.

[0033] The suffixes "module" and "section" of the components used in the following description are given or mixed in consideration of the ease of writing the specification, and they themselves do not have a special meaning or role. In addition, in the case of describing the exemplary embodiments disclosed in the specification, if it is determined that the detailed description of the related known technology may make the gist of the exemplary embodiments disclosed in the specification obscure, its detailed description will be omitted. In addition, the drawings are only used to easily understand the exemplary embodiments disclosed in the specification, and the technical concepts disclosed herein are not limited by the drawings, and all modifications included within the scope of the present disclosure should be understood to cover equivalents or alternatives.

[0034] Terms such as "first" and "second" as used herein may apply corresponding components regardless of importance or order, and are used to distinguish a component from another component without limiting the components. These terms may be used for the purpose of distinguishing one element from another.

[0035] It will be understood that when an element (e.g., a first element) is "(operably or communicably) coupled / coupled to another element (e.g., a second element)" or "connected to another element", the element may be directly coupled / coupled to the other element, and there may be an intermediate element (e.g., a third element) between the element and the other element.

[0036] Unless the context clearly dictates otherwise, a singular expression includes a plural expression.

[0037] Throughout the present disclosure, the terms "having", "may have", "including", and "may include" as used herein indicate the existence of corresponding features (e.g., elements such as values, functions, operations, or parts), and do not exclude the existence of additional features.

[0038] The expression “at least one of a, b, and c” described throughout the specification may include “a alone,” “b alone,” “c alone,” “a and b,” “a and c,” “b and c,” or “all of a, b, and c.”

[0039] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present disclosure belongs can easily implement them. However, the present disclosure can be implemented in many different forms and is not limited to the exemplary embodiments described herein.

[0040] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0041] A secondary battery is a device that converts electrical energy into chemical energy and stores (or charges), and converts the stored chemical energy back into electrical energy and releases (or discharges). Secondary batteries can be represented in various ways, and based on materials, secondary batteries can be divided into lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and lithium-ion batteries.

[0042] In particular, lithium-ion batteries have high energy density when mass and volume are considered compared to other batteries, and lithium-ion batteries are advantageous for high-speed and high-rate charging and discharging, and thus are widely used in portable devices.

[0043] Figure 1 FIG. 1 is a conceptual diagram of a conventional lithium-ion battery 10 .

[0044] The lithium-ion battery 10 is mainly composed of a cathode material 1, an anode material 2, an electrolyte solution 3 and a separator 4. The cathode material 1, as a lithium ion source, determines the capacity and average voltage of the lithium-ion battery 10. The anode material 2 stores and releases lithium ions from the cathode material 1, allowing current to flow through an external circuit. The electrolyte solution 3 helps ions to move smoothly between the cathode material 1 and the anode material 2. The separator 4 blocks the contact between the cathode material 1 and the anode material 2.

[0045] More specifically, the active material, the conductive material, the binder, and the current collector may constitute the cathode material 1 or the anode material 2 .

[0046] Active materials refer to materials that directly participate in the electrode reaction of the battery. Conductive materials are used to improve the conductivity of active materials, and binders are used to bind the conductive materials and active materials to current collectors (or substrates). Current collectors correspond to elements that serve as channels through which electrons flow smoothly.

[0047] A typical active material of the cathode material 1 is lithium. Since lithium has unstable reactivity, lithium oxide combined with oxygen can be used as the active material. Aluminum can be used for the current collector of the cathode material 1.

[0048] Meanwhile, the active material of the anode material 2 may include graphite, and the current collector may include a copper (Cu) material. Graphite satisfies structural stability and low electrochemical reactivity, which are conditions that the active material of the anode material 2 should have. In addition, graphite can store a large amount of lithium ions and is widely used due to its low price. The active material of the anode material 2 allows current to flow through an external circuit while reversibly absorbing or releasing lithium ions from the cathode material 1.

[0049] Figure 2 and Figure 3 A CNT (carbon nanotube) based sheet 20 relevant to the present disclosure is schematically shown.

[0050] The current collector of the anode material 2 may be a CNT (carbon nanotube) based sheet 20 instead of copper.

[0051] If the CNT-based sheet 20 is used as a current collector of a lithium-ion battery, unlike the anode material of an existing secondary battery, there is an advantage that a binder can be omitted and most of the excellent electrical properties of CNT can be utilized. Specifically, the CNT-based sheet 20 has high conductivity, low density, and excellent electrochemical stability. Specifically, a CNT current collector with a low density can contribute to weight reduction of a lithium-ion battery.

[0052] The CNT-based sheet 20 may be an anisotropic sheet 20a in which CNT fibers constituting the sheet have directionality, or the CNT-based sheet 20 may be an anisotropic sheet 20a in which the CNT fibers constituting the sheet have directionality. Figure 3 However, despite the above advantages, these CNT-based sheets 20 have some disadvantages when used as current collectors. Figure 2 In the case of the directional anisotropic sheet 20a shown in FIG. 1 , there is a problem that the mechanical properties deteriorate in the direction perpendicular to the orientation direction. Figure 3 In the case of the illustrated nonwoven sheet 20b, the overall mechanical properties may be insufficient, or non-uniformity may occur due to local differences in physical properties.

[0053] Figure 4 is a partial front view of an anode structure 100 according to an exemplary embodiment of the present disclosure. Figure 5 is a partial perspective view of an anode structure 100 according to another exemplary embodiment of the present disclosure. Figure 6 1 is a conceptual diagram of one form of a secondary battery 200 to which the anode structure 100 is applied.

[0054] The following embodiment proposes an anode structure 100 that complements the above CNT-based sheet. The anode structure 100 is included in an anode, and refers to a structure that may be used as a current collector or a precipitation-type anode to be described later.

[0055] The anode structure 100 may be a sheet in which a plurality of yarns 110 formed of CNT fibers are woven, that is, a CNT-based woven structure.

[0056] CNT-based woven structures can have improved electrical properties, mechanical properties, and more uniform properties.

[0057] The specific manufacturing method and structure of the CNT-based woven structure will be described below.

[0058] The anode structure 100 may be a sheet in which a plurality of yarns 110 formed of CNT fibers are woven. The anode structure 100 may have a uniform pattern.

[0059] Anode structure 100 can be woven in a variety of ways. For example, anode structure can be woven in various ways (e.g., plain weave, twill weave, and satin weave). In other words, anode structure 100 can be formed without being limited to any particular weaving method, as long as a regular texture can be formed. Anode structure 100 formed by weaving can take the form of a thin and wide sheet, and stiffness can depend on the weaving method. Figure 4 and Figure 5Some of the anode structures 100 that may be woven in the various ways described are conceptually shown. The anode structure 100 of the present disclosure may be any woven structure to the extent not inconsistent with the features described or to be illustrated.

[0060] The woven material can take the form of a sheet having only a structure of a plurality of yarns 110, without additional materials or physical / chemical treatments. However, if necessary, additional materials or physical / chemical treatments can be added. In this case, the sheet structure can be made more rigid.

[0061] The sheet-like anode structure 100 formed of CNT fibers has high conductivity, low density and excellent electrochemical stability. Specifically, since the anode structure 100 formed by weaving does not have only one direction, the possibility of a problem of a sudden decrease in mechanical properties in one direction is low. In addition, since the anode structure 100 formed by weaving has appropriate directionality, the uniformity of mechanical properties can be ensured.

[0062] Since the woven sheet-like anode structure 100 has uniform physical properties, manufacturing deviations can also be minimized. In other words, since the anode structure 100 is woven by the same method and has the same pattern, the weight, volume and thickness of the manufactured anode structure 100 are constant, which enables uniform physical properties of the secondary battery 200.

[0063] Furthermore, since the woven sheet-shaped anode structure 100 has a reinforcement structure in which the plurality of yarns 110 are fastened to each other, the anode structure 100 may have improved durability.

[0064] The anode structure 100 having the above characteristics may be included in the anode material 220 of the secondary battery 200. The anode structure 100 may be used as a skeleton in the anode material 220, for example, a support.

[0065] In the anode material 220 , an empty space formed by the anode structure 100 may be empty as it is, or may be filled with a solid electrolyte, or may be filled with a liquid electrolyte.

[0066] In addition, an empty space formed by the anode structure 100 may be filled with at least one of an active material, a polymer material (eg, a binder), and a conductive material (metal nanoparticles or carbon nanoparticles).

[0067] The secondary battery 200 of the present disclosure may include a cathode material 210, an anode material 220, an electrolyte 230, and a separator 240. Figure 1The characteristics of the elements of the described lithium ion battery 10 are the same within the scope of no contradiction. Alternatively, the secondary battery 200 of the present disclosure may not include the separator 240 .

[0068] Fig. 7A and Figure 7B Photographs of twisted yarns and braided yarns according to exemplary embodiments of the present disclosure are shown. FIG. 8A to FIG. 8D A process of forming an anode structure according to an exemplary embodiment of the present disclosure is shown.

[0069] Yarn can be defined as a plurality of CNT fiber strands that are combined (e.g., braided or twisted) together. Yarn can be defined as a yarn in which fiber strands are combined together, and a yarn in which combined fiber strands are combined together again.

[0070] The anode structure can be made of Fig. 7A Twisted yarn or Figure 7B Specifically, the anode structure can be formed by weaving a plurality of twisted yarns, or can be formed by weaving a plurality of braided yarns. Twisted yarns have the advantage of being easy to manufacture, and braided yarns have the advantage of excellent mechanical and electrical properties.

[0071] Referring to Figures 9 to Fig.11 The physical properties of twisted and braided yarns are described in detail.

[0072] The anode structure may be formed by weaving a plurality of twisted yarns or by weaving a plurality of braided yarns. The yarn of a unit to be described hereinafter is defined to mean the yarn just before being woven into the anode structure.

[0073] pass Fig. 8A and Figure 8B The unit yarns of the anode structure woven in the process are twisted yarns.

[0074] Reference Fig. 8A The unit yarn constituting the anode structure may be a primary twisted yarn. The primary twisted yarn is formed by twisting a plurality of CNT yarns into a wire.

[0075] Reference Figure 8B The unit yarn constituting the anode structure may be a secondary twisted yarn. The secondary twisted yarn is formed by twisting a plurality of primary twisted yarns.

[0076] In particular, "twisting" to form a twice twisted yarn is called "doubling".

[0077] At the same time, refer to Figure 8C and Fig.8DIn the process shown in FIG. 1 , the unit yarns constituting the anode structure may be braided yarns. The braided yarns may be Figure 8C As shown, it can be formed by weaving a plurality of primary twisted yarns, or it can be formed as shown in Fig.8D The structure shown is formed by weaving a plurality of secondary twisted yarns. Figure 8C and Fig.8D The properties of the primary twisted yarn and the secondary twisted yarn described in Fig. 8A and Figure 8B The properties of the primary twisted yarn and the secondary twisted yarn described in are the same.

[0078] However, the anode structure is not limited to the above shape or the structure shown in FIG. 8. As long as the unit yarns forming the anode structure in the form of a sheet can be formed by weaving, there is no limitation on how to form the anode structure. FIG. 8A to FIG. 8D The anode structure may be formed by various combinations of the methods shown in FIG. 8A to FIG. 8D The method is not shown in the figure.

[0079] 9A to 9D Graphs showing mechanical properties according to the type of yarn constituting the anode structure.

[0080] 9A to 9D Strain-stress curves of the anode structure are shown depending on the type of yarn constituting the anode structure. The data are shown after multiple experiments for each case. Fig.9A The case where strain is applied to a yarn in which 64 CNT threads are simply gathered (untwisted yarn) is shown. Fig. 9B A case where strain is applied to a twisted yarn formed by twisting 64 CNT threads 75 times is shown. Fig. 9C A case where strain is applied to a twisted yarn formed by twisting 64 CNT threads 150 times is shown. Fig.9D A case where strain is applied to a braided yarn formed by braiding 64 CNT wires is shown.

[0081] 9A to 9C It is shown that when strain is applied to a simple collection of CNT wires (untwisted yarn) and a twisted yarn formed by twisting the CNT wires, each test exhibits different stress characteristics. Fig.9D It is shown that when strain is applied to the braided yarn formed by braiding the CNT wires, there is almost no difference in the stress characteristics of each test.

[0082] Table 1 below shows numerical representations of the mechanical properties discussed above according to the types of unit yarns constituting the anode structure.

[0083] [Table 1] strain(%) Stress(MPa) Modulus(GPa) Untwisted yarn 7.62±1.47 901.5±227.0 9.16±2.05 75 twist yarn 11.94±1.06 1177.0±130.1 6.15±1.35 150 twist yarn 13.51±3.07 1163.9±116.2 5.34±2.43 Weaving Yarn 9.67±0.36 935.8±26.5 9.55±1.06

[0084] Table 1 shows that when the unit yarn constituting the anode structure is formed by braided yarn, the deviation values ​​of strain and stress are significantly lower than in other cases. In addition, regarding the modulus value, which is the ratio value of stress change with strain change, when the yarn constituting the anode structure is formed by braided yarn, the deviation value is the smallest when compared with other cases.

[0085] 9 and Table 1, when the unit yarn constituting the anode structure is formed of braided yarns, the uniformity of mechanical properties can be improved compared to simply aggregating CNT wires (untwisted yarns) or forming the yarns into twisted yarns.

[0086] Fig.10 Graphs showing electrical characteristics when the anode structure is formed from twisted yarns and when the anode structure is formed from braided yarns are shown.

[0087] Specifically, Fig.10 The electrical conductivity according to the type of unit yarn constituting the anode structure is shown.

[0088] Table 2 below shows the values ​​of electrical characteristics when the anode structure is formed of twisted yarns and when it is formed of braided yarns.

[0089] [Table 2]

[0090] Fig.10 Table 2 shows that when the anode structure is formed of braided yarn, the conductivity is higher and its standard deviation is smaller than that of the twisted yarn. In other words, when the anode structure is formed based on the braided yarn, the uniformity of the conductivity can be further improved.

[0091] Fig.11 Graphs showing the linear density when the anode structure is formed of twisted yarns and when formed of braided yarns are shown.

[0092] Table 3 below shows the values ​​of linear density when the anode structure is formed of twisted yarns and when it is formed of braided yarns.

[0093] [Table 3]

[0094] Fig.11As shown in Table 3, when the anode structure is formed of braided yarn, the standard deviation of the linear density is less than that of the anode structure of twisted yarn. If the linear density changes, the amount of current flowing through the anode structure or the resistance may change, and therefore it can be understood that the more uniform the linear density, the more uniform the electrical characteristics. In other words, if the anode structure is formed of braided yarn, the electrical characteristics can also be uniform due to the excellent uniformity of the linear density.

[0095] Fig.12 and Fig.13 A conceptual diagram showing before and after lithium deposition of an anode-free secondary battery or solid-state battery related to the present disclosure.

[0096] The anode structure 100 may also be applied to an anode-free secondary battery 300 or a solid-state battery 300 .

[0097] Solid-state batteries have advantages. Since solid-state batteries have solid electrolytes, the risk of electrolyte leakage is eliminated, and in solid-state batteries, separators that prevent contact between the positive electrode and the negative electrode can be omitted, and the weight and volume of the battery can be reduced. In other words, solid-state batteries have the advantages of easy implementation of large-capacity batteries and high stability. One way to implement solid-state batteries is to use lithium metal as an anode material. When compared, the oxidation / reduction reactivity and density of lithium metal are lower than other anode materials, but the ion capacity of lithium metal is higher than other anode materials. Therefore, high energy density per volume or per weight can be achieved with lithium metal. However, despite the advantages, when lithium metal is used, the so-called dendrite phenomenon may occur during charging of the solid-state battery, in which lithium crystals are formed on the surface of the anode material. When dendrite formation occurs, irreversible lithium metal is generated, and there is a change in volume. Due to dendrite formation, solid-state batteries have the characteristics of low Coulomb efficiency (in other words, low cycle characteristics) and low interface contact, and in addition, problems such as formation of strain, heating, short circuit and fire may occur.

[0098] Therefore, the present disclosure provides a secondary battery manufactured by applying the anode structure 100 to the anode-less secondary battery 300. The anode structure 100 applied to the anode-less secondary battery 300 simultaneously functions as the above-mentioned current collector and as a precipitation-type anode.

[0099] When the anode structure 100 is applied to the solid-state battery 300 , since lithium generated by reduction of lithium ions is deposited in the voids of the electrode, the volume change of the secondary battery may be minimized.

[0100] In addition, lithium can be uniformly precipitated on the contact surface with the electrolyte to prevent dendrite formation. Specifically, when the anode structure 100 in which multiple yarns are woven is applied to the solid-state battery 300, it has uniform conductivity compared to the anode structure 100 in the form of a common sheet rather than in a woven form, thereby maintaining higher charge uniformity. This shows that the precipitated lithium is uniform according to the region.

[0101] In addition, the shape change of the electrode can be minimized by the anode structure 100 being a fixed type structure. In other words, in the existing battery, as the battery is charged and discharged repeatedly, the anode composite material agglomerates, and this becomes a factor that deforms the shape of the electrode; however, when the anode structure 100 of the present disclosure is applied, even when charging and discharging are repeated, the shape change of the electrode can be minimized due to the fixed shape.

[0102] Specifically, the anode structure 100 may be disposed in a solid electrolyte 330 (more specifically, a sulfide-based electrolyte 330 ), and may be used as a current collector of an anode-less battery.

[0103] In other words, the solid-state battery 300 of the present disclosure may include: Fig.12 The structure shown in FIG. 1 is a structure in which cathode material 310 and solid electrolyte 330 are stacked in sequence. Alternatively, Fig.13 As shown, the solid-state battery 300 may include a structure in which a cathode material 310, a solid electrolyte 330, and a current collector 350 are sequentially stacked.

[0104] The anode structure 100 may be disposed in a layer of the solid electrolyte 330. Specifically, the anode structure 100 may be disposed away from the cathode material 310 or adjacent to a layer of the current collector 350.

[0105] exist Fig.12 In the solid-state battery 300 of the form shown in FIG. 1 , the solid electrolyte 330 including the anode structure 100 is used as a current collector. Fig.13 In the solid-state battery 300 of the form shown in FIG. 1 , not only the solid electrolyte 330 layer including the anode structure 100 but also a separate current collector 350 layer can be used as a current collector.

[0106] As charging and discharging are repeated, lithium ions may be reduced to form a lithium structure 340 precipitated on the anode structure 100 .

[0107] As described above, by applying the solid-state battery 300 to the anode structure 100 , low volume change can be achieved, and immobility and charge uniformity can be ensured. Embodiments of the invention

[0108] The exemplary embodiments described in the present disclosure or other exemplary embodiments are not mutually exclusive or distinct. In the above exemplary embodiments of the present disclosure or in other exemplary embodiments, each of the components or functions can be used together or in combination.

[0109] For example, component A described in a specific exemplary embodiment and / or drawings may be combined with component B in another exemplary embodiment and / or drawings. In other words, even if a combination between components is not directly described, the combination may be possible except for the case where the combination is described as impossible.

[0110] The above detailed description should not be interpreted as limiting in all aspects but should be regarded as illustrative. The scope of the present disclosure should be determined by reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0111] These and other changes can be made to the embodiments in light of the above detailed description. Generally, in the appended claims, the terms used should not be interpreted as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted as including all possible embodiments and the full range of equivalents to which such claims are entitled. Therefore, the claims are not limited by the present disclosure. Industrial Applicability

[0112] The features of the present disclosure described above may be partially or entirely applied to the field of secondary batteries.

Claims

1. A secondary battery comprising: Cathode material; and Anode material, The anode material includes an anode structure including a sheet in which a plurality of yarns formed of carbon nanotube (CNT) fibers are woven.

2. A secondary battery without an anode, comprising: Cathode material; Electrolytes; and An anode structure includes a sheet in which a plurality of yarns formed of carbon nanotube (CNT) fibers contained in the electrolyte are woven. The secondary battery according to claim 1 , wherein each of the plurality of yarns is a braided yarn.

4. The secondary battery according to claim 3, wherein the braided yarn is formed by braiding a plurality of primary twisted yarns with each other, and Each of the plurality of primary twisted yarns is formed by twisting a plurality of CNT threads.

5. The secondary battery according to claim 3, wherein the braided yarns are formed by braiding the secondary twisted yarns with each other, wherein each of the secondary twisted yarns is formed by twisting a plurality of primary twisted yarns with each other, and Each of the plurality of primary twisted yarns is formed by twisting a plurality of CNT threads. The secondary battery according to claim 1 , wherein each of the plurality of yarns is a twisted yarn. 7 . The secondary battery according to claim 6 , wherein the twisted yarn is a primary twisted yarn formed by twisting a plurality of CNT threads.

8. The secondary battery according to claim 6, wherein the twisted yarn is a secondary twisted yarn formed by twisting primary twisted yarns with each other, and Each of the primary twisted yarns is formed by twisting a plurality of CNT threads. 9 . The secondary battery according to claim 1 , wherein the anode structure is an anode current collector of a lithium ion battery.

10. The secondary battery according to claim 2, wherein the electrolyte is solid. The secondary battery according to claim 10 , wherein the electrolyte comprises a sulfide-based material. 12 . The secondary battery according to claim 1 , further comprising no separator. 13 . The secondary battery according to claim 2 , wherein each of the plurality of yarns is a braided yarn.

14. The secondary battery according to claim 13, wherein the braided yarn is formed by braiding a plurality of primary twisted yarns with each other, and Each of the plurality of primary twisted yarns is formed by twisting a plurality of CNT threads.

15. The secondary battery according to claim 13, wherein the braided yarns are formed by braiding the secondary twisted yarns with each other, wherein each of the secondary twisted yarns is formed by twisting a plurality of primary twisted yarns with each other, and Each of the plurality of primary twisted yarns is formed by twisting a plurality of CNT threads. 16 . The secondary battery according to claim 2 , wherein each of the plurality of yarns is a twisted yarn. 17 . The secondary battery according to claim 16 , wherein the twisted yarn is a primary twisted yarn formed by twisting a plurality of CNT threads.

18. The secondary battery according to claim 16, wherein the twisted yarn is a secondary twisted yarn formed by twisting primary twisted yarns with each other, and Each of the primary twisted yarns is formed by twisting a plurality of CNT threads.

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