KR20240101099A - Secondary battary, battary pack and vehicle - Google Patents

Abstract

One embodiment of the present invention includes an electrode assembly having a structure in which an anode, a separator, and a cathode are stacked and wound; a battery can accommodating the electrode assembly; and a rotating member provided between at least one end in the direction of the winding axis of the electrode assembly and the bottom surface of the battery can, wherein the negative electrode is positioned at the core of both ends in a direction perpendicular to the winding axis of the electrode assembly. A secondary battery, a battery pack, and an automobile are provided, including an in-tab provided at an end, wherein the in-tab is coupled to the rotating member.

Description

Secondary batteries, battery packs, and automobiles{SECONDARY BATTARY, BATTARY PACK AND VEHICLE}

The present invention relates to secondary batteries, battery packs, and automobiles.

Secondary batteries, which are easy to apply depending on the product group and have electrical characteristics such as high energy density, are used not only in portable devices but also in electric vehicles (EV, Electric Vehicle) and hybrid vehicles (HEV, Hybrid Electric Vehicle) that are driven by an electrical drive source. It is universally applied.

These secondary batteries not only have the primary advantage of being able to dramatically reduce the use of fossil fuels, but also have the advantage of not generating any by-products due to energy use, so they are attracting attention as a new energy source for eco-friendliness and improving energy efficiency.

Types of secondary batteries currently widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, and nickel zinc batteries. The operating voltage of these unit secondary battery cells is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack may be formed by connecting a plurality of secondary batteries in series. Additionally, a battery pack may be constructed by connecting multiple secondary batteries in parallel depending on the charge/discharge capacity required for the battery pack. Accordingly, the number of secondary batteries included in the battery pack and the type of electrical connection can be set in various ways depending on the required output voltage and/or charge/discharge capacity. Meanwhile, as types of secondary batteries, cylindrical, prismatic, and pouch-shaped secondary batteries are known, and the secondary batteries may be cylindrical secondary batteries.

The present invention seeks to provide a secondary battery that prevents battery stability problems by preventing deformation of the core portion of the cathode of the electrode assembly and preventing short circuits due to damage to the separator.

Another object of the present invention is to provide a battery pack including a secondary battery having the above improved structure and a vehicle including the same.

However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

One embodiment of the present invention includes an electrode assembly having a structure in which an anode, a separator, and a cathode are stacked and wound; a battery can accommodating the electrode assembly; and a rotating member provided between at least one end in the direction of the winding axis of the electrode assembly and the bottom surface of the battery can, wherein the negative electrode is positioned at the core of both ends in a direction perpendicular to the winding axis of the electrode assembly. A secondary battery is provided, including an in-tab provided at an end, wherein the in-tab is coupled to the rotating member.

Another embodiment of the present invention provides a battery pack including a secondary battery according to an embodiment of the present invention.

Another embodiment of the present invention provides a vehicle including a battery pack according to the above-described embodiment.

A secondary battery is formed by interposing an insulating separator between the positive and negative electrodes and winding it to form a jelly roll-shaped electrode assembly, which is then inserted into a battery can along with an electrolyte to form a secondary battery.

If the jelly roll-shaped electrode assembly has a structure in which the electrode assembly is wound by using a winding core, when the secondary battery containing it is repeatedly charged and discharged, the electrode may expand and contract, causing the positive electrode to slide toward the core. there is. The core portion of the electrode assembly is an empty space, and the negative electrode is bent together due to the sliding anode, causing deformation of the core portion. Specifically, if the in-tab provided at the end located at the core of the negative electrode is fixed by welding to the bottom of the battery can, it may not slide along the positive electrode, causing the negative electrode to bend and causing deformation of the core.

If the deformation of the core part becomes severe, stress such as a bent area of the electrode may occur, and as a result, a short circuit may occur inside the electrode assembly due to damage to the separator.

According to embodiments of the present invention, it includes a rotating member provided between an end in the winding axis direction of the electrode assembly and the bottom surface of the battery can, and an in tab ( By combining the in-tab with the rotating member, the cathode can slide along the anode when the anode slides, thereby preventing the cathode from bending and preventing deformation of the core of the electrode assembly. Therefore, it is advantageous to ensure battery stability by preventing short circuits due to damage to the separator.

However, the advantageous effects that can be obtained through the present invention are not limited to the above-described effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention includes the matters described in such drawings. It should not be interpreted as limited to only .
Figure 1 is a photograph showing that an existing negative electrode tab according to a comparative example of the present invention is fixed to the bottom of a battery can.
Figure 2 is a CT photograph showing a cross section perpendicular to the winding axis at the core of the electrode assembly according to a comparative example of the present invention.
Figure 3 is a schematic diagram of the portion indicated by a circle in Figure 2. When the positive electrode slides due to charging and discharging in a secondary battery including an electrode assembly according to a comparative example of the present invention, the fixed negative electrode is bent together and the core portion is deformed. This is a diagram showing this process.
Figure 4 is a cross section perpendicular to the winding axis at the core of the electrode assembly when the cathode according to the comparative example of the present invention includes middle tabs provided in parts other than both ends in a direction perpendicular to the winding axis of the electrode assembly. This is a CT picture showing.
Figure 5 shows that a secondary battery including an electrode assembly according to an embodiment of the present invention includes a rotating member, and an in tab provided at an end located in the core of the negative electrode engages with the rotating member and slides together along the positive electrode. This is a schematic diagram.
FIG. 6 is a diagram illustrating a process in which, when the positive electrode slides due to charging and discharging in a secondary battery including an electrode assembly according to an embodiment of the present invention, the negative electrode rotates along the positive electrode to prevent deformation of the core portion.
Figure 7 is a view showing a rotating member according to an embodiment of the present invention, where (a) shows a tripod shape and (b) shows a rotating ring shape.
Figure 8 is a diagram schematically showing the cathode and anode of the electrode assembly according to an embodiment of the present invention.
Figure 9 is a photograph showing that the negative electrode in-tab according to an embodiment of the present invention is provided on the uncoated portion of the end located in the winding core in a direction perpendicular to the winding axis of the electrode assembly.
Figure 10 is a diagram showing a schematic configuration of a battery pack including secondary batteries according to an embodiment of the present invention.

Terms or words used in this specification and claims are not to be construed limited to their ordinary or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted based on the meaning and concept consistent with the technical idea of the present invention.

The terminology used herein is only used to describe exemplary embodiments and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this specification, terms such as “include,” “equipped,” or “have” are used to describe the presence of a specific component, and do not preclude the presence or addition of other components.

Additionally, terms such as “…unit” and “device” used in the specification refer to a unit that processes at least one function or operation.

In this specification, the expression “on” a specific component is intended to express presence on one side of a specific component, and is not intended to limit the hierarchical relationship, and also refers to physical contact with the component. It is not limited, and means that other members may be additionally provided between the above components.

In this specification, the term “winding core” refers to an empty space provided at the innermost part of the electrode assembly, where a jelly roll-shaped electrode assembly is wound using the core.

In this specification, “In-tab” refers to a tab provided at the end located in the core of the electrode assembly in a direction perpendicular to the winding axis.

The embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, so various equivalents can be substituted for them at the time of filing the present application. It should be understood that there may be variations.

To facilitate understanding of the invention, the attached drawings are not drawn to scale and the dimensions of some components may be exaggerated. Additionally, the same reference numbers may be assigned to the same components in different embodiments.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

One embodiment of the present invention includes an electrode assembly having a structure in which an anode, a separator, and a cathode are stacked and wound; a battery can accommodating the electrode assembly; and a rotating member provided between at least one end in the direction of the winding axis of the electrode assembly and the bottom surface of the battery can, wherein the negative electrode is positioned at the core of both ends in a direction perpendicular to the winding axis of the electrode assembly. A secondary battery is provided, including an in-tab provided at an end, wherein the in-tab is coupled to the rotating member.

The core part is provided at the innermost part of the electrode assembly and refers to an empty space provided by winding a jelly roll-shaped electrode assembly using the core part. The empty space may be provided in a cylindrical shape.

The in-tab is a tab provided at an end located in the core of the cathode in a direction perpendicular to the winding axis of the electrode assembly. Due to the increase in the internal rigidity of the core, the inside of the electrode assembly It is possible to prevent the expansion stress from operating on the winding core.

Furthermore, the in-tab facilitates securing the roundness of the electrode assembly, compared to the case where the cathode includes middle tabs provided on parts other than both ends in a direction perpendicular to the winding axis of the electrode assembly, thereby structurally It can be stable.

The roundness refers to the degree of roundness, that is, the degree to which the circular shape of the end perpendicular to the winding axis of the electrode assembly is close to a geometrically accurate circle, specifically, the degree to which all points equidistant from the center of the circle are close to the exact circle. , the higher the roundness value, the closer it is to the shape of a circle and the more structurally stable it can be.

Figure 4 is a cross section perpendicular to the winding axis at the core of the electrode assembly when the cathode according to the comparative example of the present invention includes middle tabs provided in parts other than both ends in a direction perpendicular to the winding axis of the electrode assembly. This is a CT picture showing.

Referring to FIG. 4, when the electrode assembly of the cathode according to the comparative example of the present invention includes a middle tab 55, a flat area may be generated in the electrode assembly including the middle tab 55. , the electrode may be bent from this point and the winding core may begin to deform, making it vulnerable to deformation of the winding core. The arrow-marked portion in FIG. 4 indicates the portion where the electrode is bent by the middle tab 55 and the deformation of the core portion begins when the cathode includes the middle tab 55. Accordingly, if the deformation of the core part becomes severe, stress may occur at the area where the electrode is bent, and accordingly, a short circuit may occur due to damage to the separator inside the electrode assembly.

However, even if the negative electrode includes the in-tab, if the jelly roll-shaped electrode assembly has a structure in which the electrode assembly is wound using a winding core, when the secondary battery containing it is repeatedly charged and discharged. As expansion and contraction of the electrode occurs, the positive electrode may slide toward the core portion. At this time, the negative electrode is bent together due to the sliding positive electrode, causing deformation of the core portion. In particular, if the in-tab is fixed by welding to the bottom of the battery can and cannot slide along the positive electrode, the negative electrode may be bent and deformation of the core portion may occur.

Figure 1 is a photograph showing that the existing negative electrode tab according to the comparative example of the present invention is fixed to the bottom surface of the battery can, and Figure 2 is a photograph showing the winding core of the electrode assembly according to the comparative example of the present invention, perpendicular to the winding axis. It is a CT photograph showing a cross-section, and FIG. 3 is a schematic diagram of the portion indicated by a circle in FIG. 2. When the positive electrode slides due to charging and discharging in a secondary battery including the electrode assembly according to the comparative example of the present invention, the fixed negative electrode It represents the process in which deformation of the core part occurs as it is bent together.

Referring to Figures 1 to 3, the in tab provided at the end located in the core of the cathode 50 in the direction perpendicular to the winding axis of the electrode assembly is welded and fixed to the bottom surface of the battery can. Therefore, when charging and discharging the secondary battery is repeated, the positive electrode 30 may slide toward the core portion, but the negative electrode 50 including the in tab cannot slide together along the positive electrode 30 and is bent and wound. Deformation of the core may occur. The area marked with an

If the deformation of the core part becomes severe, stress such as a bent area of the electrode may occur, and as a result, a short circuit may occur inside the electrode assembly due to damage to the separator.

Figure 5 shows that a secondary battery including an electrode assembly according to an embodiment of the present invention includes a rotating member, and an in tab provided at an end located in the core of the negative electrode engages with the rotating member and slides together along the positive electrode. It is a schematic diagram showing, and FIG. 6 shows the process of preventing deformation of the core portion while the negative electrode rotates along the positive electrode when the positive electrode slides due to charging and discharging in a secondary battery including an electrode assembly according to an embodiment of the present invention. This is a drawing that represents.

Referring to FIGS. 5 and 6, the electrode assembly includes a rotating member 60 provided between an end in the winding axis direction A and the bottom surface 21 of the battery can, and the negative electrode of the electrode assembly 10. When the positive electrode 30 slides while repeating charging and discharging of the secondary battery by engaging the rotating member 60 with the in tab 53 provided at the end located at the core of the positive electrode 30 (50), the positive electrode 30 ), the cathode 50 can slide together, thereby preventing the cathode 50 from bending, thereby preventing deformation of the core portion of the electrode assembly 10. Therefore, it is advantageous to ensure battery stability by preventing short circuits due to damage to the separator 40.

According to one embodiment of the present invention, the rotating member includes a tab coupling portion coupled to the in tab; and a support portion connecting the tab coupling portion and the bottom surface of the battery can.

Referring to FIG. 5, the thinner the thickness of the tab coupling portion 61 and the support portion 62 may be, the more advantageous it is for stability. Specifically, as the thickness of the tab coupling portion 61 and the support portion 62 increases, the probability that the electrode may contact the beading portion (not shown) of the battery can 20 increases, which may result in a risk of short circuit.

The beading part refers to a part pressed into the inside of the battery can 20 in an area adjacent to the open end of the battery can, and the electrode assembly 10 is formed by the beading part to prevent up and down movement of the battery can ( 20) can be fixed within.

Additionally, the material of the tab coupling portion 61 and the support portion 62 is not limited as long as it does not react with the electrolyte solution, and may be, for example, Ni or Al.

The rotating member includes the tab coupling portion 61 and the support portion 62, thereby connecting the in tab 53 and the bottom surface 21 of the battery can, respectively, so that the positive electrode 30 is connected during charging and discharging. When sliding, the cathode 50 including the in tab 53 may slide along the anode 30, thereby preventing the cathode 50 from being bent.

According to one embodiment of the present invention, the support part fixes the lower surface of the tab coupling part.

The bottom surface does not mean a surface located below with respect to the direction of gravity, but refers to a side closer to the bottom surface of the battery can.

According to one embodiment of the present invention, the support portion has at least one roller.

Accordingly, compared to a secondary battery including a support structure without a roller, when the positive electrode slides during charging and discharging, the negative electrode including the phosphorus tab slides along the positive electrode to prevent the negative electrode from being deformed.

Referring to FIG. 7, which will be described later, the support portion 62 fixes the lower surface of the tab coupling portion 61 and includes a roller 70, thereby supporting the tab coupling portions 61 connected to the in-tab, respectively. By connecting this to a rotatable support portion 62, when the positive electrode slides during charging and discharging, the negative electrode including the in tab can slide along the positive electrode, thereby preventing the negative electrode from being bent. there is.

According to one embodiment of the present invention, the support portion has a tripod shape or a rotating ring shape.

Figure 7 is a view showing a rotating member according to an embodiment of the present invention, (a) showing a tripod shape and (b) showing a rotating ring shape.

Referring to Figure 7, according to an exemplary embodiment of the present invention, the tripod shape 80 includes a body portion 81 for fixing the tab coupling portion 61; and a leg portion 82 connected to the body portion 81, and a roller 70 is provided at an end of the leg portion 82.

According to another embodiment of the present invention, the rotating ring shape 90 includes a fixing part 91 that fixes the center of the tab coupling part 61; and a rotating part 92 that supports and rotates the lower surface of the tab coupling part 61, and a roller 70 is provided on the outer peripheral surface of the rotating part 92.

The length from the body portion 81 to the distal end of the leg portion 82 may be 1 mm to 3 mm in diameter from the center of the body portion 81 to the distal end of the leg portion 82.

The length from the fixing part 91 to the rotating part 92 may be 1 mm to 3 mm in diameter from the center of the fixing part 91 to the outer peripheral surface of the rotating part 92.

It is advantageous to weld the cathode in-tab to the opposite side of the body portion 81 or the fixing portion 91 by inserting a cathode welding rod with a diameter of about 1 mm between the winder cores of the electrode assembly in the above range. may vary depending on the size of the welding rod and the secondary battery production design.

The material of the body portion 81, leg portion 82, fixing portion 91, and/or rotating portion 92 is not limited as long as it does not react with the electrolyte solution, and may be, for example, Ni or Al.

When the support part 62 has a tripod shape 80 or a rotating ring shape 90, the support part 62 may be rotatable, so that the in tab and the bottom surface of the battery can are connected to charge and discharge. When the anode is slid, the cathode including the phosphorus tab may slide along the anode, thereby preventing the cathode from being bent. Accordingly, it is advantageous to ensure battery stability by preventing short circuits due to damage to the separator.

In one embodiment of the present invention, the negative electrode includes a current collector and an electrode active material layer provided on the contact material, the current collector includes an uncoated portion not provided with the electrode active material layer, and the in tab is the negative electrode. It provides a secondary battery that is provided in an uncoated area provided at an end located in the core of the.

Figure 9 is a photograph showing that the negative electrode in-tab according to an embodiment of the present invention is provided on the uncoated portion of the end located in the winding core in a direction perpendicular to the winding axis of the electrode assembly.

Referring to FIG. 9, the in tab may be provided by welding to an uncoated portion provided at an end located in the winding core portion of the cathode. The uncoated portion may have a more uniform surface compared to the holding portion provided with an active material layer, which may be advantageous for welding.

One embodiment of the present invention provides a secondary battery in which the negative electrode further includes an outer tab provided at an outer end of both ends in a direction perpendicular to the winding axis of the electrode assembly.

Figure 8 is a diagram schematically showing the cathode and anode of the electrode assembly according to an embodiment of the present invention.

Referring to FIG. 8, the cathode 50 according to an exemplary embodiment of the present invention is located on the outer side of both ends in the direction (P) perpendicular to the winding axis of the electrode assembly 10 in addition to the in tab 53. It may further include an outer tab 54 provided at one end. Since the cathode 50 includes one more outer tab 54, the resistance of the electrode assembly 10 can be reduced as the number of tabs increases, and thus the energy density can be increased.

According to another embodiment of the present invention, the cathode 50 may include only the inner tab 53 without the outer tab 54, and the number of the cathode tabs is not limited.

In an exemplary embodiment of the present invention, the positive electrode includes a current collector and an electrode active material layer provided on the contact body, and the positive electrode is disposed at at least one of both ends in a direction perpendicular to the winding axis of the electrode assembly. A secondary battery is provided in which an end of a current collector and an end of the positive electrode active material layer coincide with each other.

The fact that the end of the positive electrode current collector and the end of the positive electrode active material layer coincide at the end of the positive electrode means that the positive electrode in the electrode assembly has a free edge, and the positive electrode has a direction perpendicular to the winding axis of the electrode assembly. This may mean that uncoated areas are not formed at both ends of .

Referring to FIG. 8, the end of the positive electrode current collector and the end of the positive electrode active material layer 31 at the end of the positive electrode 30 coincide with each other, meaning that the positive electrode current collector and the positive electrode active material layer ( This means that the length of 31) is the same, and in this case, the length of the positive electrode current collector and the length of the positive electrode active material layer 31 may be within a general error range in the art. For example, the length of the positive electrode current collector relative to the length of the positive electrode active material layer 31 at the end of the positive electrode may be +0.5% or less.

One embodiment of the present invention provides a secondary battery in which the positive electrode includes middle tabs provided in portions other than both ends in a direction perpendicular to the winding axis of the electrode assembly.

Referring to FIG. 8, the positive electrode has a free edge structure as described above, and therefore, the uncoated portion 32 may not be formed at both ends of the positive electrode in the direction P perpendicular to the winding axis of the electrode assembly. there is. Accordingly, tabs cannot be welded to both ends in the direction P perpendicular to the winding axis of the electrode assembly, so the middle tab 33 may be provided in other parts. The positive electrode 30 includes tabs provided in portions other than both ends in a direction perpendicular to the winding axis of the electrode assembly, and may have, for example, a middle tab 33 structure.

The structure of the anode middle tab 33 means that it includes tabs 33 provided in parts other than both ends in the direction (P) perpendicular to the winding axis of the electrode assembly. Accordingly, both ends of the electrode assembly in the direction P perpendicular to the winding axis may have free edges on which the uncoated region 32 is not formed. The positive electrode middle tab 33 may be provided in the positive electrode uncoated area 32.

Accordingly, the positive electrode 30 has a free edge shape and a positive middle tab 33 in which the end of the positive electrode current collector and the end of the positive electrode active material layer 31 coincide at the end in the direction P perpendicular to the winding axis of the electrode assembly. It can have a structure.

According to one embodiment of the present invention, the secondary battery is a cylindrical secondary battery.

In the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate can be used without limitation as long as they are active materials known in the art.

Non-limiting examples of the positive electrode active material include common positive electrode active materials that can be used in the positive electrode of conventional electrochemical devices, especially lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or lithium composites combining these. Oxides can be used.

In one example, the positive electrode active material has _the general formula A _{[ A} Contains at least one element selected from Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; 0.1 ≤ z ≤ 2; the stoichiometric coefficients of the components included in x, y, z and M are selected so that the compound remains electrically neutral.

In another example, the positive electrode active material is an alkali metal compound xLiM ¹ O ₂ -(1-x)Li ₂ M ² O ₃ disclosed in US6,677,082, US6,680,143, etc. (M ¹ is at least one element having an average oxidation state of 3) M ² may include at least one element with an average oxidation state of 0≤x≤1).

In another example, the positive electrode active material has the general formula Li _a M ¹ _x Fe ₁ - _x M ² _y P ₁ - _y M ³ _z O _4-z (M ¹ is Ti, Si, Mn, Co, Fe, V, M ² includes at least one element selected from Cr, Mo, Ni, Nd, Al, Mg, and Al; , M ³ includes at least one element selected from As, Sb, Si, Ge, V and S; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y; < 1, 0 ≤ z <1; the stoichiometric coefficients of the components included in a, x, y, z, M ¹ , M ² , and M ³ are selected such that the compound remains electrically neutral), or Li ₃ M ₂ It may be lithium metal phosphate represented by (PO ₄ ) ₃ [M includes at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al].

Preferably, the positive electrode active material may include primary particles and/or secondary particles in which primary particles are aggregated.

Non-limiting examples of the negative electrode active material include common negative electrode active materials that can be used in the negative electrode of conventional electrochemical devices, especially lithium metal or lithium alloy, carbon, petroleum coke, activated carbon, Lithium adsorption materials such as graphite or other carbons can be used.

In one example, the negative electrode active material may be carbon material, lithium metal or lithium metal compound, silicon or silicon compound, tin or tin compound, etc. Metal oxides such as TiO ₂ and SnO ₂ with a potential of less than 2V can also be used as negative electrode active materials. As carbon materials, both low-crystalline carbon and high-crystalline carbon can be used.

Non-limiting examples of positive electrode current collectors include foils made of aluminum, nickel, or combinations thereof, and non-limiting examples of negative electrode current collectors include foils made of copper, gold, nickel, or copper alloys, or combinations thereof. There are foils, etc.

The separator is a porous polymer film, for example, a porous polymer film made of polyolefin polymers such as ethylene homopolymer, propylene homopolymer, ethylene/butene copolymer, ethylene/hexene copolymer, ethylene/methacrylate copolymer, etc. Alternatively, they can be used by stacking them. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high melting point glass fiber, polyethylene terephthalate fiber, etc.

At least one surface of the separator may include a coating layer of inorganic particles.

It is also possible that the separator itself is made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure combined with a binder such that an interstitial volume exists between adjacent particles.

The inorganic particles may be made of an inorganic material with a dielectric constant of 5 or more. As a non-limiting example, the inorganic particles include Pb(Zr,Ti)O ₃ (PZT), Pb _1-x La _x Zr _1-y Ti _y O ₃ (PLZT), PB(Mg ₃ Nb _2/3 )O ₃ -PbTiO ₃ (PMN-PT), BaTiO ₃ , hafnia(HfO ₂ ), SrTiO ₃ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , SnO ₂ , CeO ₂ , MgO, CaO, ZnO and Y ₂ O ₃ It may contain at least one substance selected from the group consisting of

The electrolyte may be a salt with a structure such as A ⁺ B ^- . Here, A ⁺ includes alkali metal cations such as Li ⁺ , Na ⁺ , K ⁺ or ions consisting of a combination thereof. And B ^- is F ^- , Cl ^- , Br ^- , I ^- , NO ₃ ^- , N(CN) ₂ ^- , BF ₄ ^- , ClO ₄ ^- , AlO ₄ ^- , AlCl ₄ ^- , PF ₆ ^- , SbF ₆ ^- , AsF ₆ ^- , BF ₂ C ₂ O ₄ ^- , BC ₄ O ₈ ^- , (CF ₃ ) ₂ PF ₄ ^- , (CF ₃ ) ₃ PF ₃ ^- , (CF ₃ ) ₄ PF ₂ ^- , (CF ₃ ) ₅ PF ^- , (CF ₃ ) ₆ P ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- , CF ₃ CF ₂ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (FSO ₂ ) ₂ N ^- , CF ₃ CF ₂ (CF ₃ ) ₂ CO ^- , (CF ₃ SO ₂ ) ₂ CH ^- , (SF ₅ ) ₃ C ^- , (CF ₃ SO ₂ ) ₃ C ^- , CF ₃ (CF ₂ ) ₇ SO ₃ ^- , CF ₃ CO ₂ ^- , CH ₃ CO ₂ ^- , SCN ^- and (CF ₃ CF ₂ SO ₂ ) ₂ N ^- and one or more anions selected from the group consisting of.

The electrolyte can also be used by dissolving it in an organic solvent. Organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and dipropyl carbonate (DPC). , dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (N-methyl- 2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), gamma butyrolactone, or mixtures thereof may be used.

Another embodiment of the present invention provides a battery pack including at least one of the above-described secondary batteries.

The cylindrical secondary battery according to the above-described embodiment can be used to manufacture a battery pack.

FIG. 10 is a diagram showing a schematic configuration of a battery pack 3 including secondary batteries 2 according to an embodiment of the present invention.

Referring to FIG. 10, the battery pack 3 according to an embodiment of the present invention includes an assembly of electrically connected cylindrical secondary batteries and a pack housing 4 that accommodates the same. The cylindrical secondary battery is the secondary battery 2 according to the above-described embodiment. In the drawing, for convenience of illustration, parts such as bus bars, cooling units, and external terminals for electrical connection of cylindrical secondary batteries are omitted.

Another embodiment of the present invention provides a vehicle including at least one of the above-described battery packs.

The battery pack can be mounted in a car. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. Motor vehicles include four-wheeled vehicles or two-wheeled vehicles.

A vehicle according to an embodiment of the present invention includes a battery pack according to an embodiment of the present invention. The vehicle operates by receiving power from a battery pack according to an embodiment of the present invention.

Although the present invention has been described above with limited examples and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the description below will be understood by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalence of the patent claims.

2: Secondary battery
3: Battery pack
4: Pack housing
10: Electrode assembly
20: Battery can
21: Bottom surface of battery can
30: anode
31: Anode electrode active material layer
32: Anode uncoated area
33: positive middle tab
40: Separator
50: cathode
51: Negative electrode active material layer
52: cathode uncoated region
53: cathode in tab
54: cathode outer shell tab
55: cathode middle tab
60: Rotating member
61: tab joint
62: support part
70: roller
80: Tripod shape
81: body part
82: Legs
90: Rotating ring shape
91: fixing part
92: Rotating part
C: core part
A: Winding axis direction
P: Direction perpendicular to the winding axis

Claims (14)

An electrode assembly having a structure in which an anode, a separator, and a cathode are stacked and wound;
a battery can accommodating the electrode assembly; and
Comprising a rotating member provided between at least one end in the winding axis direction of the electrode assembly and the bottom surface of the battery can,
The cathode includes an in-tab provided at an end located in the core of both ends in a direction perpendicular to the winding axis of the electrode assembly,
A secondary battery wherein the in tab is coupled to the rotating member. In claim 1,
The rotating member includes a tab coupling portion coupled to the in tab; and
A secondary battery comprising a support part connecting the tab coupling part and the bottom surface of the battery can. In claim 1,
The support part is a secondary battery that secures the lower surface of the tab coupling part. In claim 2,
A secondary battery wherein the support portion includes at least one roller. In claim 2,
A secondary battery wherein the support portion has a tripod shape or a rotating ring shape. In claim 5,
The tripod shape includes a body portion that secures the tab coupling portion; and
Includes a leg portion connected to the body portion,
A secondary battery in which a roller is provided at an end of the leg portion. In claim 5,
The rotating ring shape includes a fixing part that fixes the center of the tab coupling part; and
It includes a rotating part that supports and rotates the lower surface of the tab coupling part,
A secondary battery in which a roller is provided on the outer peripheral surface of the rotating part. In claim 1,
The negative electrode includes a current collector and an electrode active material layer provided on the contact body,
The current collector includes an uncoated portion not provided with the electrode active material layer,
The secondary battery wherein the in tab is provided in an uncoated portion provided at an end located in the core of the negative electrode. The secondary battery according to claim 1, wherein the negative electrode further includes an outer tab provided at an outer end of both ends in a direction perpendicular to the winding axis of the electrode assembly. In claim 1,
The positive electrode includes a current collector and an electrode active material layer provided on the current collector,
The positive electrode is a secondary battery in which an end of the positive electrode current collector and an end of the positive electrode active material layer coincide at least one of both ends in a direction perpendicular to the winding axis of the electrode assembly. In claim 1,
The positive electrode is a secondary battery including middle tabs provided in portions other than both ends in a direction perpendicular to the winding axis of the electrode assembly. In claim 1,
The secondary battery is a cylindrical secondary battery. A battery pack including a secondary battery according to any one of claims 1 to 12. A motor vehicle comprising at least one battery pack according to claim 13.