Secondary battery

Abstract

To provide a secondary battery in which the imbalance of a liquid electrode due to crossover is eliminated, and also to provide a secondary battery in which a short circuit does not occur and crossover is resolved.SOLUTION: A secondary battery according to an embodiment of the present invention includes: a first liquid electrode in which a first half reaction occurs; a second liquid electrode in which a second half reaction occurs; a hollow frame 110 forming a first electrode accommodating portion that is a space in which the first liquid electrode is stored and a second electrode accommodating portion that is a space in which the second liquid electrode is stored; and a separation membrane 120 coupled to the frame and disposed between the first electrode accommodating portion and the second electrode accommodating portion. The frame includes a transition portion 112 that communicates the first electrode accommodating portion and the second electrode accommodating portion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a secondary battery, and more particularly, to a secondary battery in which metal ions dissolved in an electrolyte are oxidized and reduced for charge and discharge.

Background Art

[0002] A redox flow battery (RFB) is a system in which an active material in electrolytes is oxidized and reduced for charge and discharge, different from existing secondary batteries, and is an electrochemical energy storage device that stores electrical energy as chemical energy of an electrolyte solution. In fact, in a redox flow battery, an electrochemical reaction occurs in a stack and it operates by continuously circulating an electrolyte inside the stack using a fluid pump. These redox flow batteries have the advantages of long life, high output, and high capacity, but on the other hand, there are problems due to spatial constraints and design complexity caused by a tank for storing the electrolyte and a fluid pump for flowing the electrolyte. For this reason, the inventors of the present invention developed a redox secondary battery that removes the electrolyte tank and the fluid pump, but there was a problem that the performance of the secondary battery deteriorated and the life was reduced due to electrolyte imbalance caused by a crossover phenomenon in which metal ions and water pass through a separation membrane during charge and discharge.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The problem to be solved by the present invention is to provide a secondary battery that eliminates the imbalance of a liquid electrode due to crossover.

[0004] Another problem of the present invention is to provide a secondary battery in which no short circuit occurs and crossover is solved.

[0005] The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

Means for Solving the Problems

[0006] In order to achieve the above problems, a secondary battery according to an embodiment of the present invention includes a first liquid electrode where a first half-reaction occurs, a second liquid electrode where a second half-reaction occurs, a first electrode accommodating portion which is a space where the first liquid electrode is stored, a second electrode accommodating portion which is a space where the second liquid electrode is stored, a hollow frame forming the first electrode accommodating portion and the second electrode accommodating portion, and a separator membrane coupled to the frame and disposed between the first electrode accommodating portion and the second electrode accommodating portion. The frame includes a transition portion communicating the first electrode accommodating portion and the second electrode accommodating portion.

[0007] The frame is formed in a hollow rectangle, and a part of the transition portion may be disposed along one side of the frame.

[0008] The frame includes a separator membrane support portion protruding inward and coupled to the separator membrane, and the transition portion may be disposed outside the separator membrane support portion.

[0009] The secondary battery further includes a first current collector contacting the first electrode accommodating portion side of the frame and electrically connected to the first liquid electrode, and a first gasket sealing between the first current collector and the frame. The frame includes a first gasket insertion portion into which the first gasket is inserted, and the transition portion may be disposed inside the first gasket insertion portion.

[0010] The secondary battery may further include a first insulator attached to the frame so that the first liquid electrode or the second liquid electrode flowing through the transition portion does not hit the first current collector, in contact with the first electrode accommodating portion side of the frame and electrically connected to the first liquid electrode.

[0011] The first insulator can seal between the first current collector and the frame.

[0012] The first insulator may be laminated between the first current collector and the frame.

[0013] The first insulator may be a film coated on the first current collector.

[0014] The transition portion may be bent at least twice or more.

[0015] Among the plurality of bends of the transition portion, at least one bend may be bent from the in-plane direction to the out-of-plane direction or from the out-of-plane direction to the in-plane direction.

[0016] The transition portion can penetrate the plane formed by the separation membrane.

[0017] The transition portion can be orthogonal to the plane formed by the separation membrane.

[0018] A part of the transition portion may be arranged in a direction parallel to the plane formed by the separation membrane.

[0019] The secondary battery further includes a first solid electrode disposed in the first electrode accommodating portion and impregnated with the first liquid electrode, and a second solid electrode disposed in the second electrode accommodating portion and impregnated with the second liquid electrode. The transition portion may be disposed at a part around the first solid electrode or the second solid electrode.

[0020] The secondary battery further includes a first solid electrode disposed in the first electrode accommodating portion and impregnated with the first liquid electrode, and a second solid electrode disposed in the second electrode accommodating portion and impregnated with the second liquid electrode. The transition portion may be disposed around the entire circumference of the first solid electrode or the second solid electrode.

[0021] The transition portions may be arranged in a direction in which at least two portions are aligned with each other.

[0022] The secondary battery further includes a liquid electrode injection part for injecting the first liquid electrode and the second liquid electrode into the first electrode accommodation part and the second electrode accommodation part, and the liquid electrode injection part can communicate with the transition part.

[0023] The first liquid electrode and the second liquid electrode may be injected into the first electrode accommodation part and the second electrode accommodation part through the liquid electrode injection part.

[0024] The width of the cross section of the transition part may be smaller than half of the thickness of the frame.

[0025] The frame is formed in a hollow rectangle, and the overall length of the transition part may be longer than the length of the long side of the frame.

[0026] To achieve the above problems, the secondary battery according to an embodiment of the present invention includes a first liquid electrode in which a first half reaction occurs, a second liquid electrode in which a second half reaction occurs, a separation membrane disposed between the first liquid electrode and the second liquid electrode, and a frame supporting the separation membrane, and the frame may include a transition part through which the first liquid electrode and / or the second liquid electrode flows.

[0027] To achieve the above problems, the secondary battery according to an embodiment of the present invention includes a first current collector, a second current collector disposed separately from the first current collector, a separation membrane disposed between the first current collector and the second current collector, a first liquid electrode disposed between the first current collector and the separation membrane, where a first half reaction occurs and is electrically connected to the first current collector, a second liquid electrode disposed between the second current collector and the separation membrane, where a second half reaction occurs and is electrically connected to the second current collector, and a hollow frame disposed between the first current collector and the second current collector so that the first liquid electrode and the second liquid electrode do not leak in the in-plane direction, and the frame may include a transition part through which the first liquid electrode and / or the second liquid electrode flows.

[0028] To achieve the above object, a secondary battery according to an embodiment of the present invention includes a first current collector, a second current collector disposed apart from the first current collector, a separator disposed between the first current collector and the second current collector, and a frame disposed between the first current collector and the second current collector to form a first electrode accommodating portion between the first current collector and the separator and a second electrode accommodating portion between the second current collector and the separator. The frame may include a transition portion that communicates the first electrode accommodating portion and the second electrode accommodating portion.

[0029] To achieve the above object, a secondary battery according to an embodiment of the present invention includes a first current collector, a second current collector disposed apart from the first current collector, a separator disposed between the first current collector and the second current collector, and a frame disposed between the first current collector and the second current collector to form a first electrode accommodating portion between the first current collector and the separator and a second electrode accommodating portion between the second current collector and the separator. The frame may include a separator support portion that protrudes inward in the in-plane direction to support the separator.

[0030] Specific matters of other embodiments are included in the detailed description and the drawings.

Advantages of the Invention

[0031] According to the secondary battery of the present invention, it has one or more of the following effects.

[0032] First, it eliminates the imbalance of the liquid electrodes due to crossover, has the advantages of a high-output and high-capacity redox secondary battery, and has the advantages of no performance degradation and no reduction in lifespan.

[0033] Second, it eliminates the imbalance of the liquid electrodes and has the advantage that no short circuit occurs between the first liquid electrode and the second liquid electrode.

[0034] Third, while minimizing the possibility of leakage of the liquid electrodes by the frame, it also has the advantage of being able to support the separator.

[0035] Fourth, there is also an advantage that an insulator is disposed between the transition portion and the current collector to prevent damage to the current collector by the liquid electrode.

[0036] Fifth, there is also an advantage that the separation membrane support portion suppresses the expansion and contraction of the liquid electrode, the generation of gas in the liquid electrode, or the deformation of the frame due to an external impact or the like.

[0037] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

Brief Description of the Drawings

[0038]

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Figure 21

Embodiments for Carrying Out the Invention

[0039] The advantages, features, and methods for achieving them of the present invention will become clear by referring to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various different forms. These embodiments are provided merely to complete the disclosure of the present invention and to fully inform those with ordinary knowledge in the technical field to which the present invention pertains of the scope of the invention. The present invention is defined only by the scope of the claims. The same reference numerals throughout the specification refer to the same components.

[0040] Even though terms such as first, second, etc. are used to describe various components, these components are of course not limited by these terms. These terms are merely used to distinguish one component from another, and unless otherwise stated to the contrary, the first component may of course be the second component.

[0041] Unless otherwise stated to the contrary throughout the specification, each component may be in the singular or in the plural.

[0042] In the following, when it is stated that any configuration is arranged "above (or below)" a component or "on (or under)" a component, this means that not only is any configuration arranged in contact with the upper surface (or lower surface) of the said component, but other configurations may also be interposed between the said component and any configuration arranged "on (or under)" the said component.

[0043] Also, when a component is described as being "connected", "coupled" or "joined" to another component, it should be understood that the components may be directly connected or joined to each other, but other components may be "interposed" between the components, or each component may be "connected", "coupled" or "joined" through other components.

[0044] The singular expressions used in this specification include plural expressions unless the context clearly dictates otherwise. Terms such as "configured" or "including" in this application should not necessarily be construed as including all of the multiple components or multiple steps described in the specification, and some of the components or some of the steps may not be included, or it should be construed that additional components or steps may be further included.

[0045] When it is stated as "A and / or B" throughout the specification, this means A, B or A and B unless otherwise stated to the contrary, and when it is stated as "C to D", this means C or more and D or less unless otherwise stated to the contrary.

[0046] Hereinafter, the present invention will be described with reference to the drawings for explaining a secondary battery according to an embodiment of the present invention.

[0047] FIG. 1 and FIG. 2 are exploded perspective views of a secondary battery according to an embodiment of the present invention, FIG. 3 is a perspective view of a secondary battery according to an embodiment of the present invention, FIG. 4 is a cross-sectional view taken along the line A-A of the secondary battery shown in FIG. 3, and FIG. 5 is a perspective view of a secondary battery module according to an embodiment of the present invention.

[0048] A secondary battery according to an embodiment of the present invention includes a first liquid electrode where a first half-reaction occurs, a second liquid electrode where a second half-reaction occurs, a first electrode accommodating portion 111a which is a space for storing the first liquid electrode, a second electrode accommodating portion 111b which is a space for storing the second liquid electrode, a hollow frame 110 forming the first and second electrode accommodating portions, a separator 120 coupled to the frame 110 and disposed between the first electrode accommodating portion 111a and the second electrode accommodating portion 111b, a first current collector 130a contacting the first electrode accommodating portion 111a side of the frame 110 and electrically connected to the first liquid electrode, a second current collector 130b contacting the second electrode accommodating portion 111b side of the frame 110 and electrically connected to the second liquid electrode, a first solid electrode 150a disposed in the first electrode accommodating portion 111a and impregnated with the first liquid electrode, a second solid electrode 150b disposed in the second electrode accommodating portion 111b and impregnated with the second liquid electrode, a first insulator 170a adhering between the frame 110 and the first current collector 130a, and a second insulator 170b adhering between the frame 110 and the second current collector 130b.

[0049] The first liquid electrode is an electrolyte in which an anode redox couple is dissolved. The anode redox couple can be embodied with a material containing at least one of vanadium (V), zinc (Zn), bromine (Br), chromium (Cr), manganese (Mn), titanium (Ti), iron (Fe), cerium (Ce), and cobalt (Co). In this embodiment, V 2+ / V 3+It is a redox couple. The first liquid electrode may be an acidic aqueous solution that is a solution that conducts current by ionization, and preferably contains sulfuric acid. The first liquid electrode in this embodiment is H 2 SO 4 aqueous solution with VOSO 4 (vanadyl sulfate) or V 2 O 5 (vanadium pentoxide) dissolved therein can be manufactured.

[0050] The first liquid electrode undergoes a first half-reaction. The first half-reaction is as follows, where → indicates the discharge reaction direction and ← indicates the charge reaction direction. V 2+ ←→V 3+ +e -

[0051] During discharge, divalent vanadium ions are oxidized to trivalent vanadium ions, and during charging, trivalent vanadium ions are reduced to divalent vanadium ions.

[0052] The first liquid electrode is surrounded by a frame 110, a first current collector 130a, and a separator 120. The first liquid electrode does not flow out in the in-plane direction or the like by the frame 110 between the first current collector 130a and the separator 120. The first liquid electrode is housed in a first electrode housing portion 111a. The first liquid electrode is preferably impregnated in the first solid electrode 150a.

[0053] The first liquid electrode is electrically connected to the first current collector 130a, and during discharge, electrons move to the first current collector 130a, and during charging, the electrons of the first current collector 130a move to the first liquid electrode. The first liquid electrode is in contact with the separator 120, and hydrogen cations (protons) are moved through the separator 120.

[0054] The second liquid electrode is an electrolyte in which a cathode redox couple is dissolved. The cathode redox couple can be embodied by a material containing at least one of vanadium (V), zinc (Zn), bromine (Br), chromium (Cr), manganese (Mn), titanium (Ti), iron (Fe), cerium (Ce), and cobalt (Co). In this embodiment, V 4+ / V 5+ is the redox couple. The second liquid electrode may be an acidic aqueous solution that is a solution that conducts current by ionization, and preferably contains sulfuric acid. The second liquid electrode in this embodiment is an aqueous solution of H 2 SO 4 in which VOSO 4 (vanadyl sulfate) or V 2 O 5 (vanadium pentoxide) is dissolved and can be manufactured.

[0055] The second liquid electrode undergoes a second half-reaction. The second half-reaction is as follows, where → indicates the discharge reaction direction and ← indicates the charge reaction direction. V 5+ +e - ←→V 4+

[0056] During discharge, vanadium pentavalent ions are reduced to vanadium tetravalent ions, and during charging, vanadium tetravalent ions are oxidized to vanadium pentavalent ions.

[0057] The second liquid electrode is provided surrounded by the frame 110, the second current collector 130b, and the separator 120. The second liquid electrode does not flow out in the in-plane direction or the like by the frame 110 between the second current collector 130b and the separator 120. The second liquid electrode is housed in the second electrode housing portion 111b. The second liquid electrode is preferably impregnated in the second solid electrode 150b.

[0058] The second liquid electrode is electrically connected to the second current collector 130b. During charging, electrons move to the second current collector 130b, and during discharging, the electrons of the second current collector 130b move to the second liquid electrode. The second liquid electrode is in contact with the separation membrane 120, and hydrogen cations (protons) are moved through the separation membrane 120.

[0059] As described above, the first liquid electrode and the second liquid electrode have the same components. The first liquid electrode and the second liquid electrode are those in which vanadium ions are contained in an electrolyte of the same component. Hereinafter, the first liquid electrode and the second liquid electrode are generically referred to as the liquid electrode.

[0060] The frame 110 is formed in a hollow rectangle. Depending on the embodiment, the frame 110 can be formed in a rhombus, a circle, a triangle, or a polygon with five or more sides. The frame 110 has a predetermined thickness in the out-of-plane direction and forms a first electrode accommodating portion 111a and a second electrode accommodating portion 111b.

[0061] The hollow space of the frame 110 is divided by the separation membrane 120 into a first electrode accommodating portion 111a and a second electrode accommodating portion 111b. The separation membrane 120 is coupled to the center of the frame 110 in the out-of-plane direction (thickness direction). The frame 110 supports the separation membrane 120.

[0062] The first current collector 130a is disposed on one side of the frame 110 in the out-of-plane direction, and the second current collector 130b is disposed on the other side. The hollow of the frame 110 is closed by the first current collector 130a and the second current collector 130b. The frame 110 is disposed between the first current collector 130a and the second current collector 130b to prevent the first liquid electrode and the second liquid electrode from leaking in the in-plane direction or the like. The frame 110 forms a first electrode accommodating portion 111a between the first current collector 130a and the separation membrane 120, and forms a second electrode accommodating portion 111b between the second current collector 130b and the separation membrane 120.

[0063] Frame 110 houses the first liquid electrode and the second liquid electrode. Inside the frame 110, the first solid electrode 150a and the second solid electrode 150b are disposed. The first gasket 160a is coupled to one side edge of the frame 110, and the second gasket 160b is coupled to the other side edge. The first insulator 170a adheres to one side of the frame 110, and the second insulator 170b adheres to the other side.

[0064] Frame 110 includes a transition portion 112 that communicates the first electrode accommodating portion 111a and the second electrode accommodating portion 111b. A part of the transition portion 112 is formed as an in-plane groove on the edge of the frame 110, and another part thereof is formed as an out-of-plane hole. In the transition portion 112 formed in the frame 110, the first liquid electrode and / or the second liquid electrode flows. A detailed description of the frame 110 and the transition portion 112 will be described later with reference to FIGS. 6 to 11.

[0065] The separation membrane 120 is disposed inside the frame 110 to separate the first liquid electrode and the second liquid electrode, and to allow hydrogen cations (protons) to move between the first liquid electrode and the second liquid electrode. The separation membrane 120 is disposed inside the frame 110 to divide the first electrode accommodating portion 111a and the second electrode accommodating portion 111b. The separation membrane 120 is disposed between the first current collector 130a and the second current collector 130b. The edge of the separation membrane 120 is coupled to the frame 110. Hydrogen cations move from the first liquid electrode to the second liquid electrode during discharge and move from the second liquid electrode to the first liquid electrode during charging.

[0066] The separation membrane 120 can include perfluorinated ionomer, partially fluorinated polymer, and non-fluorinated hydrocarbons. The separation membrane 120 can be formed of or include Nafion (registered trademark), Flemion (registered trademark), NEOSEPTA-F (registered trademark), or Gore Select (registered trademark).

[0067] The separation membrane 120 must prevent the first liquid electrode and the second liquid electrode from mixing with each other. However, during charging and discharging, a crossover phenomenon may occur where vanadium ions and water contained in the first liquid electrode and the second liquid electrode pass through the separation membrane 120. As a result, an imbalance occurs between the amounts of the first liquid electrode and the second liquid electrode, which affects the performance and lifespan of the secondary battery. In the case of a conventional redox secondary battery with a liquid electrode tank and a pump, although such an imbalance in these liquid electrodes can be eliminated, in the case where only a small amount of liquid electrodes exist inside the secondary battery as in the present invention, even a small difference in the imbalance will affect the performance and lifespan of the secondary battery. The transition portion 112 eliminates such an imbalance caused by crossover, and the first liquid electrode or the second liquid electrode with an increased volume moves to the first liquid electrode or the second liquid electrode with a decreased volume through the transition portion 112.

[0068] The first current collector 130a is disposed on one side of the frame 110 and forms a first electrode accommodating portion 111a together with the frame 110 and the separation membrane 120. The first current collector 130a is disposed in parallel and separated from the second current collector 130b. The first current collector 130a is in close contact with the first gasket 160a disposed on the frame 110. The first current collector 130a contacts the first insulator 170a and does not directly contact the first liquid electrode or the second liquid electrode flowing through the transition portion 112. The first current collector 130a is electrically connected to the first liquid electrode, and electrons move so that current flows during charging and discharging.

[0069] As shown in FIG. 5, when a plurality of secondary batteries composed of a plurality of frames 110, a plurality of first current collectors 130a, and a plurality of second current collectors 130b form a module, the plurality of first current collectors 130a are electrically connected by a bus bar (not shown) to connect the plurality of secondary batteries in parallel.

[0070] The first current collector 130a is formed of metal and includes a first metal current collector 131a that is electrically connected to the bus bar and a first carbon current collector 132a disposed between the first metal current collector 131a and the frame 110.

[0071] The first carbon current collector 132a is formed of a material such as graphite, carbon, or carbon plastic, and has high electrical conductivity and high acid resistance. The first carbon current collector 132a is disposed between the first liquid electrode and the first metal current collector 131a to allow electrons to move between them, while preventing the first metal current collector 131a from oxidizing. The first carbon current collector 132a may be formed in a rectangular plate shape or may be formed by coating the first metal current collector 131a.

[0072] The first metal current collector 131a is formed of a metal with high electrical conductivity, such as copper or aluminum. Although the first metal current collector 131a is formed in a rectangular plate shape, a part thereof may protrude and be connected to a bus bar.

[0073] The first metal current collector 131a may be formed of a ductile thin film or a rigid plate. As shown in FIG. 5, when a plurality of secondary batteries form a module, although the plurality of first metal current collectors 131a are formed of a ductile thin film, only a part thereof may be formed of a rigid plate.

[0074] The first carbon current collector 132a is disposed on one surface of the first metal current collector 131a. As shown in FIG. 5, when a plurality of secondary batteries form a module, the first carbon current collectors 132a are disposed on both surfaces of the first metal current collector 131a, respectively.

[0075] The second current collector 130b is disposed on the other side of the frame 110 and forms a second electrode accommodating portion 111b together with the frame 110 and the separator 120. The second current collector 130b is disposed parallel to and separated from the first current collector 130a. The second current collector 130b is in close contact with the second gasket 160b disposed on the frame 110. The second current collector 130b is in contact with the second insulator 170b and is not directly in contact with the first liquid electrode or the second liquid electrode flowing through the transition portion 112. The second current collector 130b is electrically connected to the second liquid electrode so that electrons move to allow current to flow during charging and discharging.

[0076] As shown in FIG. 5, when a plurality of secondary batteries composed of a plurality of frames 110, a plurality of first current collectors 130a, and a plurality of second current collectors 130b form a module, the plurality of second current collectors 130b are electrically connected by a bus bar (not shown) to connect the plurality of secondary batteries in parallel.

[0077] The second current collector 130b includes a second metal current collector 131b formed of metal and electrically connected to the bus bar, and a second carbon current collector 132b disposed between the second metal current collector 131b and the frame 110.

[0078] The second carbon current collector 132b is formed of a material such as graphite, carbon, or carbon plastic, and has high electrical conductivity and high acid resistance. The second carbon current collector 132b is disposed between the second liquid electrode and the second metal current collector 131b to allow mutual electron transfer and prevent oxidation of the second metal current collector 131b. The second carbon current collector 132b may be formed in a rectangular plate shape or may be formed by coating the second metal current collector 131b.

[0079] The second metal current collector 131b is formed of a metal with high electrical conductivity, such as copper or aluminum. Although the second metal current collector 131b is formed in a rectangular plate shape, a part thereof may protrude and be connected to the bus bar.

[0080] The second metal current collector 131b may be formed of a ductile thin film or a rigid plate. As shown in FIG. 5, when a plurality of secondary batteries form a module, although the plurality of second metal current collectors 131b are formed of a ductile thin film, a part of them may be formed of a rigid plate.

[0081] The second carbon current collector 132b is disposed on one surface of the second metal current collector 131b. As shown in FIG. 5, when a plurality of secondary batteries form a module, the second carbon current collectors 132b are respectively disposed on both surfaces of the second metal current collector 131b.

[0082] A secondary battery according to an embodiment of the present invention may further include a first gasket 160a that seals between the first current collector 130a and the frame 110, and a second gasket 160b that seals between the second current collector 130b and the frame 110.

[0083] The first gasket 160a and the second gasket 160b may be formed of an elastic rubber or synthetic resin. The first gasket 160a and the second gasket 160b may be formed in a rectangular strip shape.

[0084] The first solid electrode 150a is impregnated with the first liquid electrode and disposed in the first electrode accommodating portion 111a. The first solid electrode 150a is disposed surrounded by the frame 110, the first current collector 130a, and the separator 120. The first solid electrode 150a includes a carbon-based material such as carbon or graphite felt, carbon cloth, carbon black, graphite powder, or graphene. The first solid electrode 150a may be formed in a porous rectangular parallelepiped shape. The first solid electrode 150a may have a thickness that is even thicker than the out-of-plane thickness of the first electrode accommodating portion 111a, and in this case, it may be press-fitted and accommodated in the first electrode accommodating portion 111a. The first solid electrode 150a is in close contact with the first current collector 130a and the separator 120.

[0085] The second solid electrode 150b is impregnated with the second liquid electrode and disposed in the second electrode accommodating portion 111b. The second solid electrode 150b is disposed surrounded by the frame 110, the second current collector 130b, and the separator 120. The second solid electrode 150b includes a carbon-based material such as carbon or graphite felt, carbon cloth, carbon black, graphite powder, or graphene. The second solid electrode 150b may be formed in a porous rectangular parallelepiped shape. The second solid electrode 150b may have a thickness that is even thicker than the out-of-plane thickness of the second electrode accommodating portion 111b, and in this case, it may be press-fitted and accommodated in the second electrode accommodating portion 111b. The second solid electrode 150b is in close contact with the second current collector 130b and the separator 120.

[0086] The first insulator 170a adheres to the frame 110 such that the first liquid electrode or the second liquid electrode flowing through the transition portion 112, particularly the first liquid electrode or the second liquid electrode flowing through the groove portion of the transition portion 112, does not directly contact the first current collector 130a, that is, it covers the portion formed by the groove of the transition portion 112. The first insulator 170a prevents the first liquid electrode or the second liquid electrode flowing through the transition portion 112 from being electrically connected to the first current collector 130a.

[0087] The first insulator 170a is formed according to the shape of the transition portion 112 and is formed in a rectangular shape that is long in one direction in this embodiment. The first insulator 170a is composed of a synthetic resin having low electrical conductivity and high acid resistance. The first insulator 170a may be formed as a film coated on the first current collector 130a, particularly the first carbon current collector 132a. The first insulator 170a adheres to the portion formed by the groove and exposed among the transition portions 112 formed on the frame 110 so that the transition portion 112 is not exposed. The first insulator 170a is laminated between the first current collector 130a and the frame 110.

[0088] The second insulator 170b adheres to the frame 110 such that the first liquid electrode or the second liquid electrode flowing through the transition portion 112, particularly the first liquid electrode or the second liquid electrode flowing through the groove portion of the transition portion 112, does not directly contact the second current collector 130b, that is, it covers the portion formed by the groove of the transition portion 112. The second insulator 170b prevents the first liquid electrode or the second liquid electrode flowing through the transition portion 112 from being electrically connected to the second current collector 130b.

[0089] The second insulator 170b is formed according to the shape of the transition portion 112, and in this embodiment, it is formed in a rectangular shape that is long in one direction. The second insulator 170b is composed of a synthetic resin having low electrical conductivity and high acid resistance. The second insulator 170b may be formed of a film coated on the second current collector 130b, particularly the second carbon current collector 132b. The second insulator 170b adheres to the portion exposed by the groove among the transition portions 112 formed in the frame 110 so that the transition portion 112 is not exposed. The second insulator 170b is laminated between the second current collector 130b and the frame 110.

[0090] Describing the overall configuration of the secondary battery according to the present invention configured as described above, it is as follows.

[0091] The separator 120 is disposed at the center in the out-of-plane direction of the rectangular frame 110 having a predetermined thickness. The first current collector 130a is disposed on one side in the out-of-plane direction of the frame 110, and the second current collector 130b is disposed on the other side in the out-of-plane direction, thereby forming the first electrode accommodating portion 111a and the second electrode accommodating portion 111b. That is, the frame 110 is disposed between the first current collector 130a and the second current collector 130b, and the separator 120 is disposed within the frame 110.

[0092] Referring to FIG. 5, the above-described configurations intersect to form a repeating module. That is, the first current collector 130a may be disposed between a plurality of frames 110 to which the separator 120 is coupled, and the second current collector 130b may be disposed between a plurality of frames 110 to which the separator 120 is coupled.

[0093] The first solid electrode 150a impregnated with the first liquid electrode is disposed in the first electrode accommodating portion 111a, and the second solid electrode 150b impregnated with the second liquid electrode is disposed in the second electrode accommodating portion 111b. The first gasket 160a and the first insulator 170a are disposed between the first current collector 130a and the frame, and the second gasket 160b and the second insulator 170b are disposed between the second current collector 130b and the frame.

[0094] The first current collector 130a includes a first carbon current collector 132a and a first metal current collector 131a, and the second current collector 130b includes a second carbon current collector 132b and a second metal current collector 131b. A first insulator 170a, a first carbon current collector 132a, and a first metal current collector 131a are sequentially laminated on the transition portion 112 on the side of the first electrode accommodating portion 111a. A second insulator 170b, a second carbon current collector 132b, and a second metal current collector 131b are sequentially laminated on the transition portion 112 on the side of the second electrode accommodating portion 111b.

[0095] FIG. 6 is a drawing showing in detail a part of the cross-sectional view shown in FIG. 4, FIG. 7 is a front view of a frame of a secondary battery according to an embodiment of the present invention, FIG. 8 is a cross-sectional view of the frame shown in FIG. 7 in the B-B direction, FIG. 9 is a cross-sectional view of the frame shown in FIG. 7 in the C-C direction, FIG. 10 is a bottom view and a cross-sectional view in the D-D direction of a frame of a secondary battery according to an embodiment of the present invention, and FIG. 11 is a drawing showing the flow of a liquid electrode through a transition portion of a secondary battery according to an embodiment of the present invention.

[0096] A frame 110 according to an embodiment of the present invention includes a hollow rectangular frame body 119, a separator support portion 115 that protrudes inward from the hollow of the frame body 119 and is coupled to a separator 120, a first gasket insertion portion 113a formed by a groove on one side edge of the frame body 119 into which a first gasket 160a is inserted, a second gasket insertion portion 113b formed by a groove on the other side edge of the frame body 119 into which a second gasket 160b is inserted, a transition portion 112 formed on the frame body 119, and a liquid electrode injection portion 114 that protrudes outward from the frame body 119 and into which a first liquid electrode and a second liquid electrode are injected.

[0097] The separation membrane support portion 115 protrudes inward in the in-plane direction (central direction) in the frame body 119 and is formed in a rectangular shape. The separation membrane 120 has its edge coupled to the separation membrane support portion 115 so as to be stretched taut. The separation membrane support portion 115 preferably has the minimum width capable of supporting the separation membrane 120. The separation membrane support portion 115 serves as a rib for reinforcing the in-plane direction etc. of the frame body 119, and prevents the frame body 119 from deforming in the in-plane direction etc. even when expansion or contraction of the first liquid electrode or the second liquid electrode occurs, gas is generated in the liquid electrode, or an external impact etc. occurs.

[0098] To prevent the first liquid electrode or the second liquid electrode from leaking between the separation membrane support portion 115 and the separation membrane 120, one side surface of the separation membrane support portion 115 is completely adhered and coupled to the separation membrane 120. An adhesive and / or a sealer may be interposed between the separation membrane support portion 115 and the separation membrane 120. The separation membrane 120 may be fused to the separation membrane support portion 115.

[0099] The first gasket insertion portion 113a and the second gasket insertion portion 113b are formed at the edges of different side surfaces of the frame body 119. The first gasket insertion portion 113a and the second gasket insertion portion 113b may be formed as rectangular grooves along the edge of the frame body 119 and form a rectangular band shape as a whole. The first gasket insertion portion 113a and the second gasket insertion portion 113b are formed outside the in-plane direction from the transition portion 112 in the frame body 119.

[0100] The liquid electrode injection portion 114 is formed on one side of the periphery of the frame body 119 and serves as an injection port through which the liquid electrode is injected into the first electrode housing portion 111a and the second electrode housing portion 111b. The liquid electrode injection portion 114 is closed after the injection of the liquid electrode. Depending on the embodiment, the liquid electrode injection portion 114 may be removed after the injection and closing of the liquid electrode.

[0101] Referring to FIG. 10, the liquid electrode injection part 114 communicates with the transition part 112. Since the transition part 112 communicates with the first electrode accommodating part 111a and the second electrode accommodating part 111b, the liquid electrode injection part 114 communicates with the first electrode accommodating part 111a and the second electrode accommodating part 111b via the transition part 112.

[0102] The transition part 112 communicates the first electrode accommodating part 111a and the second electrode accommodating part 111b so that the imbalance between the amount of the first liquid electrode and the amount of the second liquid electrode due to crossover generated during charging and discharging is eliminated. During charging and discharging, the first liquid electrode or the second liquid electrode flows inside.

[0103] The transition part 112 preferably has a volume in which only half of the difference between the amount of the first liquid electrode and the amount of the second liquid electrode due to crossover can flow and is formed in an elongated shape so as to have a resistance value equal to or higher than a certain level.

[0104] The transition part 112 may be formed and arranged in various shapes. A part of the transition part 112 is formed by a groove in the in-plane direction along the edge of the frame body 119, and another part is formed by a hole in the out-of-plane direction. Referring to FIG. 11, the transition part 112 may be bent at least two or more times. At least one of the plurality of bends of the transition part 112 is bent from the in-plane direction to the out-of-plane direction or from the out-of-plane direction to the in-plane direction. The direction in which the transition part 112 is bent from the in-plane direction to the in-plane direction and the direction in which the transition part 112 is bent from the in-plane direction to the out-of-plane direction can be orthogonal to each other. At least a part of the transition part 112 is arranged in a direction penetrating the plane formed by the separation membrane 120. The transition part 112 can be orthogonal to the plane formed by the separation membrane 120. At least a part of the transition part 112 is arranged in a direction parallel to the plane formed by the separation membrane 120 (in-plane direction). The transition part 112 is formed in a part of the frame body 119 surrounding the first solid electrode 150a or the second solid electrode 150b and is arranged in a part around the first solid electrode 150a or the second solid electrode 150b. At least two parts of the transition part 112 may be arranged in a direction aligned with each other.

[0105] The transition part 112 preferably has a width of the cross-section of the groove or hole, particularly the depth of the part formed by the groove, smaller than half of the thickness (width in the out-of-plane direction) of the frame body 119. The transition part 112 preferably has a width of the cross-section of the groove or hole, particularly the depth of the part formed by the groove, smaller than the thickness (width in the out-of-plane direction) of the first electrode accommodating part 111a or the second electrode accommodating part 111b. The overall length of the transition part 112 is preferably similar to or longer than the length of the long side of the frame body 119. The smaller the cross-sectional area of the transition part 112 is, the longer it is preferably formed.

[0106] Referring to FIGS. 9 and 11, the transition part 112 in this embodiment is formed along one side in the in-plane direction of the frame body 119 and then bent, formed in the out-of-plane direction of the frame body 119 and then further bent, and formed and arranged along one side in the in-plane direction of the frame body 119.

[0107] The transition part 112 is arranged on the outer side in the in-plane direction than the separation membrane support part 115. The transition part 112 is arranged on the inner side in the in-plane direction than the first gasket insertion part 113a or the second gasket insertion part 113b. The part formed by the groove of the transition part 112 is covered by the first insulator 170a and the second insulator 170b and is not exposed to the outside.

[0108] The operation of the transition part 112 of the secondary battery according to the present invention configured as described above is as follows.

[0109] During charging and discharging, vanadium ions and water contained in the first liquid electrode and the second liquid electrode pass through the separation membrane 120, and an imbalance occurs in which the amount of either the first liquid electrode or the second liquid electrode increases. Among the first liquid electrode and the second liquid electrode, the liquid electrode with an increased amount moves to the liquid electrode with a decreased amount through the transition part 112. As the transition part 112 is formed in an elongated shape, even if the liquid electrode flows through the transition part 112, the first liquid electrode and the second liquid electrode do not electrically short-circuit.

[0110] FIG. 12 is an exploded perspective view of a secondary battery according to another embodiment of the present invention, FIG. 13 is a front view of a frame of a secondary battery according to another embodiment of the present invention, FIG. 14 is a front view of a secondary battery and an insulator according to another embodiment of the present invention, FIG. 15 is a partial cross-sectional view of a secondary battery according to another embodiment of the present invention, and FIG. 16 is a drawing showing the flow of a liquid electrode through a transition portion of a secondary battery according to another embodiment of the present invention.

[0111] The transition portion 212 of the secondary battery according to another embodiment of the present invention may be formed in a shape close to a rectangular shape along the edge of the frame body 119. The transition portion 212 may be disposed along the entire circumference of the first solid electrode 150a or the second solid electrode 150b. The transition portion 212 is bent three times along the edge in the in-plane direction of the frame body 119 to form a pattern close to a rectangle, and then bent to form a shape formed in the out-of-plane direction of the frame body 119.

[0112] The first insulator 260a and the second insulator 260b of the secondary battery according to another embodiment of the present invention are formed in a rectangular strip shape to cover the transition portion 212. In this embodiment, the first gasket 160a, the second gasket 160b, the first gasket insertion portion 113a, and the second gasket insertion portion 113b are omitted, and the first insulator 270a and the second insulator 270b are formed in a rectangular strip shape to cover the groove portion of the transition portion 112. Each of the first insulator 260a and the second insulator 260b seals between the first current collector 130a and the frame 110 and between the second current collector 130b and the frame 110. Each of the first insulator 260a and the second insulator 260b is in complete contact with the first current collector 130a and the frame 110, and the second current collector 130b and the frame 110 to prevent the first liquid electrode and the second liquid electrode from flowing out to the outside.

[0113] FIGS. 17 to 21 are drawings showing various embodiments of the frame of the secondary battery of the present invention.

[0114] The frame 110 can further include a frame reinforcement part 116 that is disposed in the hollow part of the frame body 119 to prevent the frame body 119 from deforming.

[0115] The frame reinforcement part 116 is formed to connect either a side of the frame body 119 to another side or a vertex of the frame body 119 to another vertex. The frame reinforcement part 116 connects at least two sides or two vertices across the hollow part so as to prevent the rectangular frame body 119 from deforming into a rhombus or a circle.

[0116] Since the frame reinforcement part 116 is formed to connect at least two sides or two vertices of the frame body 119, it may be disposed or formed on the separation membrane support part 115.

[0117] The frame reinforcement part 116 in FIG. 17 is formed on the separation membrane support part 115 so as to connect two opposite sides of the frame body 119. The frame reinforcement part 116 in the present embodiment is formed in a cross shape so as to connect the center of one side of the frame body 119 to the center of the opposite side.

[0118] The frame reinforcement part 216 in FIG. 18 is formed on the separation membrane support part 115 so as to connect two opposite vertices of the frame body 119. The frame reinforcement part 216 in the present embodiment is formed in an X shape to connect two opposite vertices.

[0119] The frame reinforcement part 316 in FIG. 19 is formed in a mesh shape and is disposed on the separation membrane support part 115.

[0120] The frame reinforcement part 416 in FIG. 20 is a wire that connects two opposite sides and is connected to a hole formed in the separation membrane support part 115.

[0121] The frame reinforcement part 516 in FIG. 21 is disposed at each vertex of the separation membrane support part 115 and connects two adjacent sides.

[0122] In the above, the preferred embodiments of the present invention have been shown and described. However, the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made by those having ordinary knowledge in the technical field to which the invention pertains without departing from the gist of the invention claimed in the claims. These modifications should not be individually understood from the technical idea and perspective of the present invention.

Industrial Applicability

[0123] The present invention is applied to secondary batteries used in energy storage devices (Energy Storage System, ESS), uninterruptible power supply systems (Uninterruptible Power Supply system, UPS), electric locomotive charging stations, etc., which store electrical energy and supply it when needed.

Claims

1. a first liquid electrode at which a first half-reaction takes place; a second liquid electrode at which the second half-reaction takes place; a hollow frame forming a first electrode receiving portion, which is a space in which the first liquid electrode is stored, and a second electrode receiving portion, which is a space in which the second liquid electrode is stored; and a separator coupled to the frame and disposed between the first electrode receiving portion and the second electrode receiving portion; The frame includes a transition portion communicating the first electrode housing portion and the second electrode housing portion. Secondary battery.

2. The frame is formed into a hollow rectangle, The transition portion is disposed partially along one side of the frame. The secondary battery according to claim 1 .

3. the frame includes a separation membrane support part protruding inwardly and coupled to the separation membrane, The transition portion is disposed outside the separation membrane support portion. The secondary battery according to claim 1 .

4. a first current collector that contacts the first electrode housing portion side of the frame and is electrically connected to the first liquid electrode; and a first gasket for sealing between the first current collector and the frame; the frame includes a first gasket insert portion into which the first gasket is inserted; the transition portion is disposed inwardly of the first gasket insert; The secondary battery according to claim 1 .

5. a first current collector that contacts the first electrode housing portion side of the frame and is electrically connected to the first liquid electrode; and a first insulator attached to the frame so that the first liquid electrode or the second liquid electrode flowing through the transition portion does not come into contact with the first current collector; The secondary battery according to claim 1 .

6. The first insulator provides a seal between the first current collector and the frame. The secondary battery according to claim 5 .

7. The first insulator is laminated between the first current collector and the frame. The secondary battery according to claim 5 .

8. The first insulator is a film applied to the first current collector. The secondary battery according to claim 5 .

9. The transition portion is folded at least two times. The secondary battery according to claim 1 .

10. At least one of the plurality of folds in the transition portion is folded from an in-plane direction to an out-of-plane direction or from an out-of-plane direction to an in-plane direction. The secondary battery according to claim 9.

11. The transition portion penetrates the plane of the separation membrane. The secondary battery according to claim 1 .

12. The transition portion is perpendicular to the plane of the separation membrane. The secondary battery according to claim 11.

13. The transition portion is disposed in a direction parallel to a plane of the separation membrane. The secondary battery according to claim 1 .

14. a first solid electrode disposed in the first electrode housing and impregnated with the first liquid electrode; and a second solid electrode disposed in the second electrode receiving portion and impregnated with the second liquid electrode; the transition portion is disposed on a portion of a circumference of the first solid electrode or the second solid electrode; The secondary battery according to claim 1 .

15. a first solid electrode disposed in the first electrode housing and impregnated with the first liquid electrode; and a second solid electrode disposed in the second electrode receiving portion and impregnated with the second liquid electrode; the transition portion is disposed around an entire circumference of the first solid electrode or the second solid electrode; The secondary battery according to claim 1 .

16. The transition portion is oriented such that at least two portions are aligned with each other. The secondary battery according to claim 1 .

17. a liquid electrode injection section for injecting the first liquid electrode and the second liquid electrode into the first electrode receiving section and the second electrode receiving section, the liquid electrode inlet portion communicates with the transition portion; The secondary battery according to claim 1 .

18. The first liquid electrode and the second liquid electrode are injected into the first electrode housing portion and the second electrode housing portion via the liquid electrode injection portion. The secondary battery according to claim 17.

19. The transition portion has a cross-sectional width that is less than half the thickness of the frame. The secondary battery according to claim 1 .

20. The frame is formed into a hollow rectangle, The transition portion has an overall length greater than the length of the long side of the frame. The secondary battery according to claim 1 .

21. a first liquid electrode at which a first half-reaction takes place; a second liquid electrode at which the second half-reaction takes place; a separation membrane disposed between the first liquid electrode and the second liquid electrode; and A frame supporting the separation membrane is included, the frame includes a transition portion through which the first liquid electrode and / or the second liquid electrode flows; Secondary battery.

22. A first current collector; a second current collector disposed spaced apart from the first current collector; a separator disposed between the first current collector and the second current collector; a first liquid electrode disposed between the first current collector and the separator, where a first half-reaction occurs, the first liquid electrode being electrically connected to the first current collector; a second liquid electrode disposed between the second current collector and the separator, where a second half-reaction occurs, the second liquid electrode being electrically connected to the second current collector; and the first liquid electrode and the second liquid electrode include a hollow frame disposed between the first current collector and the second current collector so as not to leak in an in-plane direction; the frame includes a transition portion through which the first liquid electrode and / or the second liquid electrode flows; Secondary battery.

23. A first current collector; a second current collector disposed spaced apart from the first current collector; a separator disposed between the first current collector and the second current collector; and a frame disposed between the first current collector and the second current collector, the frame forming a first electrode receiving portion between the first current collector and the separator, and the frame forming a second electrode receiving portion between the second current collector and the separator, The frame includes a transition portion communicating the first electrode housing portion and the second electrode housing portion. Secondary battery.

24. A first current collector; a second current collector disposed spaced apart from the first current collector; a separator disposed between the first current collector and the second current collector; a frame disposed between the first current collector and the second current collector, the frame forming a first electrode receiving portion between the first current collector and the separation membrane, and the frame forming a second electrode receiving portion between the second current collector and the separation membrane; Including, The frame includes a separation membrane support portion that protrudes inward in an in-plane direction and supports the separation membrane. Secondary battery.

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