Electrode composite membrane and electrochemical device including the same

Abstract

The present invention relates to an electrode composite membrane and an electrochemical element including the same. The electrode composite membrane of the present invention includes an electrode plate including an electrode portion and a reinforcing material portion, an electrolyte membrane arranged on one side of the electrode plate, a support arranged on the other side of the electrode plate, and an adhesive portion arranged on at least a portion of the facing portions of the electrode plate and the support, and the electrode portion includes a current collector and an active material layer arranged on the current collector, the electrolyte membrane is in contact with at least a portion of the active material layer and is in close contact with the electrode portion and the reinforcing material portion without being spaced apart, and the reinforcing material portion has a thickness that is the same as or thinner than the thickness of the electrode portion, is arranged to surround the entire circumference or at least a portion of a side portion of the electrode portion, and is in surface contact with the side portion of the electrode portion without being spaced apart.

Description

[Technical Field]

[0001] The present invention relates to an electrode composite membrane and an electrochemical device including the same.

[0002] This application claims priority based on Korean Patent Application No. 2022-0071071, filed on June 10, 2022, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] The rapid increase in the use of fossil fuels has led to an increasing demand for alternative and clean energy sources, and one of the most actively researched areas of this is the field of electrochemical power generation and storage.

[0004] Secondary batteries are widely used as power sources for portable electronic devices. Lithium secondary batteries, a typical example of such secondary batteries, are not only used as an energy source for mobile devices, but are also increasingly being used as a power source for electric vehicles and hybrid electric vehicles, which can replace vehicles that use fossil fuels such as gasoline and diesel, which are one of the main causes of air pollution. Their use is also expanding to include auxiliary power sources for grid-connected vehicles.

[0005] The structure of a lithium secondary battery is relatively simple, with three major components—anode, cathode, and electrolyte—being the focus of research and development. Lithium secondary batteries are powered by the movement of lithium ions from the cathode to the anode and from the anode to the cathode, with the electrolyte acting as a conductor. Widely used lithium secondary batteries utilize an electrolyte solution in which lithium salts are dissolved in an aprotic organic solvent. However, these electrolyte solutions present problems in use, such as electrolyte leakage and gas generation. To address these issues, the development of all-solid-state batteries is needed.

[0006] Meanwhile, the manufacturing process of lithium secondary batteries can be broadly divided into three steps: the electrode process, the assembly process, and the chemical formation process. The electrode process for manufacturing all-solid-state batteries involves a detailed process of pressurizing the manufactured electrodes and electrolyte membrane, during which the edges of the electrodes and electrolyte membrane frequently become detached. This can lead to short circuits between the electrodes in the subsequent assembly process, reducing the manufacturing yield and potentially resulting in poor performance of batteries using the manufactured electrode composite membrane. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide an electrode composite membrane that is an electrolyte membrane-electrode composite for use in an all-solid-state battery, which has excellent adhesive strength between the electrode and the electrolyte membrane.

[0008] In particular, the present invention aims to provide an electrode composite membrane in which the edge detachment phenomenon when the electrode and the electrolyte membrane are pressurized is improved. [Means for solving the problem]

[0009] In order to solve the above problems, according to one aspect of the present invention, there is provided an electrode composite membrane of the following embodiment.

[0010] The electrode composite membrane according to the first embodiment includes an electrode plate including an electrode portion and a reinforcing material portion, an electrolyte membrane arranged on one side of the electrode plate, a support body arranged on the other side of the electrode plate, and an adhesive portion arranged on at least a portion of the facing portions of the electrode plate and the support body, wherein the electrode portion includes a current collector and an active material layer arranged on at least one side of the current collector, the electrolyte membrane is in contact with at least a portion of the active material layer and is in close contact with the electrode portion and the reinforcing material portion without being spaced apart, and the reinforcing material portion has a thickness that is the same as or thinner than the thickness of the electrode portion, is arranged so as to surround the entire periphery or at least a portion of the side portion of the electrode portion, and is in surface contact with the side portion of the electrode portion without being spaced apart.

[0011] According to a second embodiment, the electrolyte membrane in the first embodiment may be disposed so as to cover the entire surface of one surface of the electrode plate.

[0012] According to the third embodiment, in the first or second embodiment, the reinforcing material portion may have a thickness thinner than the thickness of the electrode portion and be arranged to surround the entire periphery of the side portion of the electrode portion.

[0013] According to the fourth embodiment, in any of the first to third embodiments, the reinforcing material portion is arranged around the side portion of the electrode portion at a predetermined interval so as to surround only a portion of the side portion of the electrode portion, and the area around which the reinforcing material portion is arranged may be 50% or more of the entire circumference of the side portion of the electrode portion.

[0014] According to a fifth embodiment, in any one of the first to fourth embodiments, the support may be disposed so as to cover the entire surface of one surface of the electrode plate.

[0015] According to a sixth embodiment, in any one of the first to fifth embodiments, the adhesive portion may be disposed over the entire area of ​​the facing portions of the electrode plate and the support body.

[0016] According to a seventh embodiment, in any one of the first to sixth embodiments, the reinforcing material portion may include a polyolefin-based polymer.

[0017] According to the eighth embodiment, in any of the first to seventh embodiments, the adhesive portion may contain a fluorine-based polymer, an acrylic-based polymer, a urethane-based polymer, an epoxy-based polymer, an imide-based polymer, or a mixture of two or more of these.

[0018] According to a ninth embodiment, in any one of the first to eighth embodiments, the electrolyte membrane may be a film-like electrolyte membrane containing a solid electrolyte.

[0019] According to another aspect of the present invention, there is provided an electrochemical device having the following embodiments.

[0020] According to the tenth embodiment, an electrode assembly including a positive electrode and a negative electrode and a case for housing the electrode assembly are included, and at least one of the positive electrode and the negative electrode may be an electrode composite membrane according to any one of the first to ninth embodiments.

[0021] According to an eleventh embodiment, in the tenth embodiment, the electrochemical device may be a lithium secondary battery.

[0022] According to a twelfth embodiment, in the tenth or eleventh embodiment, the electrochemical device may be an all-solid-state battery. [Effects of the Invention]

[0023] The electrode composite membrane according to one embodiment of the present invention has the effect of improving the adhesive strength between the electrode and the electrolyte membrane by improving the curling phenomenon of the electrode after the electrode and the electrolyte membrane are pressed.

[0024] This can improve the short circuit occurrence phenomenon during battery manufacturing, thereby demonstrating the effect of improving the battery manufacturing yield.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concepts of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a layout diagram of each component of an electrode composite membrane 1 according to one embodiment of the present invention. [Figure 2A] FIG. 1 is a top view of an electrode plate 10 according to an embodiment of the present invention. [Figure 2B] 1 is a perspective view of an electrode plate 10 according to an embodiment of the present invention. [Figure 2C] 1 is a perspective view of an electrode plate 10 according to an embodiment of the present invention. [Figure 3A] FIG. 1 is a top view of an electrode plate 10 according to an embodiment of the present invention. [Figure 3B] 1 is a perspective view of an electrode plate 10 according to an embodiment of the present invention. [Figure 3C] 1 is a perspective view of an electrode plate 10 according to an embodiment of the present invention. [Figure 4A] FIG. 1 is a top view of an electrode plate 10 according to an embodiment of the present invention. [Figure 4B] 1 is a perspective view of an electrode plate 10 according to an embodiment of the present invention. [Figure 4C] 1 is a perspective view of an electrode plate 10 according to an embodiment of the present invention. [Figure 5A] 1 is a diagram illustrating the layout of a support 30 and adhesive portion 40 according to one embodiment of the present invention. [Figure 5B] 1 is a diagram illustrating the layout of a support 30 and adhesive portion 40 according to one embodiment of the present invention. [Figure 6] 1 is a photograph showing the appearance of an electrode composite membrane according to Example 1 in the present specification. [Figure 7] 1 is a photograph showing the appearance of an electrode composite membrane according to Comparative Example 1 in the present specification. [Figure 8] 1 is a photograph showing the appearance of an electrode composite membrane according to Comparative Example 3 in the present specification. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be described in detail below. However, the present invention is not limited to the following content, and each component may be modified in various ways or mixed as needed. Therefore, it should be understood that the present invention includes all modifications, equivalents, and alternatives that fall within the spirit and technical scope of the present invention.

[0028] In this specification, when a part is said to "comprise" a certain component, this does not mean that it excludes other components, but that it may further include other components, unless otherwise specified.

[0029] In this specification, the term "A and / or B" means "A or B, or both."

[0030] Certain terminology used in the following detailed description of the invention is for convenience only and is not intended to be limiting. Additionally, directional words such as top, bottom, side, center, and outside designate directions in the drawings to which reference is made or directions toward or away from the geometric center of the designated item, respectively.

[0031] According to one aspect of the present invention, an electrode composite membrane is provided.

[0032] In this specification, the electrode composite membrane refers to a composite of an electrolyte membrane and an electrode, which includes an electrolyte membrane and an electrode formed on one side of the electrolyte membrane.

[0033] FIG. 1 shows a layout diagram of each component of an electrode composite membrane according to one embodiment of the present invention.

[0034] An electrode composite membrane 1 according to one embodiment of the present invention comprises an electrode plate 10 including an electrode portion 101 and a reinforcing material portion 102, an electrolyte membrane 20 arranged on one side of the electrode plate, a support 30 arranged on the other side of the electrode plate, and an adhesive portion 40 arranged on at least a portion of the facing portions of the electrode plate and the support, the electrode portion comprising a current collector and an active material layer arranged on the current collector, the electrolyte membrane being in contact with at least a portion of the active material layer and being in close contact with the electrode portion and the reinforcing material portion without being spaced apart, the reinforcing material portion having a thickness equal to or thinner than that of the electrode portion, being arranged so as to surround the entire periphery or at least a portion of the side portion of the electrode portion, and being in surface contact with the side portion of the electrode portion without being spaced apart.

[0035] In this specification, unless otherwise specified, the direction in which each component of the electrode composite membrane is stacked is referred to as the top and bottom, and the opposite direction is referred to as the left and right.

[0036] In this specification, for convenience, one surface of the electrode plate is referred to as the first surface, and the surface behind the first surface is referred to as the second surface, where the first surface of the electrode plate is referred to as the surface facing the electrolyte membrane, and the second surface of the electrode plate is referred to as the surface facing the support.

[0037] According to one embodiment of the present invention, the electrode composite membrane 1 includes a reinforcing member 102 disposed on the electrode plate 10 so as to surround at least a portion of a periphery of the side of the electrode member 101. Thus, in a conventional manufacturing process for an all-solid-state battery, when the electrode plate and the electrolyte membrane are stacked and pressed in contact with each other, the adhesive strength of the outer edge portions of the facing portions of the electrode plate and the electrolyte membrane is poor, which is greater than the center portion, and this can improve the curling phenomenon of the electrode plate.

[0038] Specifically, in the electrode composite membrane 1, a support 30 is provided on the back surface of the electrode plate 10 facing the electrolyte membrane 20 in order to minimize deformation of the electrode plate 10 due to pressure when pressurized, and an adhesive part 40 is provided between the electrode plate 10 and the support 30 in order to improve adhesion between them.

[0039] In the present invention, the electrode plate includes a current collector and an active material layer disposed on the current collector, and the electrolyte membrane is disposed on the surface of the active material layer. The electrolyte membrane is disposed in close contact with both the electrode portion and the reinforcing material portion without being spaced apart from them.

[0040] In one embodiment of the present invention, when assembling a battery using the electrode composite membrane, in order to prevent direct contact between active material layers of electrodes having opposite polarities, it may be preferable that the area of ​​one side of the electrode unit 101 is smaller than the area of ​​one side of the electrolyte membrane at the facing portion of the electrode plate 10 and the electrolyte membrane 20. Specifically, it is preferable that the electrolyte membrane 20 is disposed so as to cover the entire surface of the active material layers of the electrode unit.

[0041] In one embodiment of the present invention, as described above, when the area of ​​one side of the electrode unit 101 is smaller than the area of ​​one side of the electrolyte membrane, i.e., when the electrolyte membrane cannot cover the entire surface of the active material layer of the electrode unit, it is preferable that the area of ​​one side of the electrolyte membrane 20 is arranged to cover the entire area of ​​one side of the electrode plate 10 in order to prevent curling of the electrode plate 10 and / or the electrolyte membrane 20. In order for the area of ​​one side of the electrolyte membrane to cover the entire area of ​​one side of the electrode plate, the area of ​​one side of the electrolyte membrane and the area of ​​one side of the electrode plate may be the same, or the area of ​​one side of the electrolyte membrane may be arranged to be larger than the area of ​​one side of the electrode plate.

[0042] In another embodiment of the present invention, it is preferable that the area of ​​one side of the electrolyte membrane 20 is at least larger than the area of ​​one side of the electrode portion 101, so that the surface of the active material layer of the electrode portion is completely covered by the electrolyte membrane.

[0043] In one embodiment of the present invention, as described above, not only one surface of the electrode portion 101 but also one surface of the electrode plate 10 may be completely covered by the electrolyte membrane, and the reinforcing material portion 102 may be arranged to surround the entire periphery of the side surface of the electrode portion 101 and be in surface contact with the side surface of the electrode portion without any separation.

[0044] 2A shows a top view of an electrode plate 10 according to an embodiment of the present invention. Referring to FIG. 2A, the reinforcing member 102 may be disposed to surround the entire periphery of the side surface of the electrode member 101 and may be in surface contact with the side surface of the electrode member without any separation. In this case, the shape of the outer periphery of the reinforcing member 102 is not limited to the shape with four angular corners as shown in FIG. 2, but may be the same as the shape of the electrolyte membrane (not shown) that contacts the electrode plate 10.

[0045] In the present invention, the reinforcing member 102 has a thickness equal to or thinner than that of the electrode member 101. This prevents a problem that occurs when the reinforcing member is thicker than the electrode member, such as a decrease in adhesive strength between the electrode member and the electrolyte membrane when the electrode plate and the electrolyte membrane are pressed together.

[0046] 2B, when the reinforcing member is disposed to surround the entire periphery of the side of the electrode and is in surface contact with the side of the electrode without being spaced apart, the reinforcing member may be thinner than the electrode, which is a preferred shape when there is a large difference in thickness between the electrode before and after pressure application, but the present invention is not limited thereto.

[0047] 2C, when the reinforcing material portion is disposed so as to surround the entire periphery of the side portion of the electrode portion and is in surface contact with the side portion of the electrode portion without any separation, the thickness of the electrode portion and the thickness of the reinforcing material portion may be the same. This is a preferable shape for improving adhesive strength with the support disposed on the underside of the electrode plate 10, as the difference in thickness between before and after pressure application is small or almost negligible, but the present invention is not limited thereto.

[0048] According to one embodiment of the present invention, an embodiment in which the thickness of the reinforcing material part is arranged to be thinner than the thickness of the electrode part so that the reinforcing material part and the current collector do not come into contact with each other may be a more preferable embodiment in terms of improving the electrochemical performance of the battery.

[0049] In one embodiment of the present invention, the thickness of the reinforcing material portion is equal to or thinner than the thickness of the electrode portion, as described above, and the thickness of the reinforcing material may be, for example, 10% to 100%, specifically 50% to 100%, or 80% to 100% of the total thickness of the electrode portion. When the thickness of the reinforcing material is within the above range, excellent effects can be obtained in terms of adhesive strength after pressure is applied to the electrode plate and the electrolyte membrane, but the present invention is not limited thereto.

[0050] In one embodiment of the present invention, the reinforcing material portion 102 may be arranged to surround only a portion of the side surface of the electrode portion 101 and may be in surface contact with the side surface of the electrode plate without any separation therebetween.

[0051] 3A and 4A each show a top view of an electrode plate 10 according to an embodiment of the present invention, and FIGS. 3B, 3C, 4B, and 4C each show a perspective view of an electrode plate 10 according to an embodiment of the present invention.

[0052] Referring to Fig. 3A, the reinforcing material parts 102 may be arranged to surround only the side surfaces of the four corners of the electrode part 101. Also, referring to Fig. 4A, the reinforcing material parts 102 may be arranged to surround only a portion of the side surfaces of the electrode part, spaced apart at predetermined intervals around the side surfaces of the electrode part.

[0053] At this time, referring to Figures 3B and 4B, when the reinforcing material portion is arranged to surround only a portion of the side portion of the electrode portion and is in surface contact with the side portion of the electrode portion without any separation, the thickness of the reinforcing material portion can be arranged to be even thinner than the thickness of the electrode portion.

[0054] Also, referring to Figures 3C and 4C, when the reinforcing material portion is arranged to surround only a portion of the side portion of the electrode portion and is in surface contact with the side portion of the electrode portion without any separation, the thickness of the electrode portion and the thickness of the reinforcing material portion may be the same.

[0055] In one embodiment of the present invention, when the reinforcing material portion is arranged to surround only a portion of the side surface of the electrode portion, the area around which the reinforcing material portion is arranged is, for example, 50% or more of the entire circumference of the side surface of the electrode portion, specifically 60% or more, 70% or more, or 80% or more, but the present invention is not limited thereto.

[0056] As described above, the electrode composite membrane 1 includes a support 30 on the second surface of the electrode plate 10 to minimize deformation of the electrode plate due to pressure when pressure is applied to bond the electrode plate and the electrolyte membrane.

[0057] In one embodiment of the present invention, the support may preferably have a surface area larger than that of the electrode unit 101 in order to support the entire electrode unit. Specifically, the support may preferably be disposed to cover the entire surface of the current collector of the electrode unit.

[0058] In addition, in order for the support to support the entire second surface of the electrode plate, it may be preferable that the area of ​​the support be equal to or larger than the area of ​​the electrode plate. Specifically, it may be preferable that the support be disposed so as to cover the entire second surface of the electrode plate.

[0059] In addition, the electrode composite membrane includes an adhesive portion 40 between the electrode plate 10 and the support 30 to improve the adhesive strength between the support and the electrode plate.

[0060] 5A and 5B show layout diagrams of a support 30 and adhesive 40, respectively, according to one embodiment of the present invention.

[0061] Referring to FIG. 5A, the adhesive 40 may be disposed to cover the entire surface of the support 30 .

[0062] FIG. 5B shows another embodiment for the placement of adhesives, in which the adhesives 40 can be placed on a portion of the support 30 .

[0063] In this case, in order to ensure uniform strength between the electrode unit and the support, the adhesive may be disposed on at least a portion, preferably the entirety, of the opposing surface of the support and the electrode unit.

[0064] In one embodiment of the present invention, the material used for the reinforcing material portion as described above is not particularly limited as long as it has little or no electrochemical reaction with the electrode active material and / or electrolyte material in the electrode portion and does not degrade the performance of the battery.

[0065] In one embodiment of the present invention, the material of the reinforcing member may include, for example, a polyolefin polymer, as a non-limiting example.

[0066] Examples of the polyolefin polymer include, but are not limited to, polyethylene, polypropylene, polybutylene, polypentene, polyhexene, polyoctene, copolymers of two or more of ethylene, propylene, butene, pentene, 4-methylpentene, hexene, hepsene, and octene, and mixtures thereof.

[0067] In one embodiment of the present invention, the material of the reinforcing member may include polyethylene, polypropylene, or a mixture thereof.

[0068] In one embodiment of the present invention, the material of the support may include, but is not limited to, a polyolefin polymer, a cellulose-based nonwoven fabric, or a mixture thereof.

[0069] The polyolefin polymer may incorporate the above-mentioned materials for the reinforcing material portion. In one embodiment of the present invention, the material of the support body and the material of the reinforcing material portion may be the same or different, but are not limited thereto.

[0070] The cellulose-based nonwoven fabric refers to a porous sheet containing cellulose fibers, and any type known in the art can be used, and is not particularly limited thereto.

[0071] In one embodiment of the present invention, the adhesive portion can be made of any material without particular limitation as long as it exhibits adhesiveness to both the support and the electrode plate.

[0072] In one embodiment of the present invention, the material of the adhesive portion may be, by way of non-limiting example, a fluorine-based polymer, an acrylic-based polymer, a urethane-based polymer, an epoxy-based polymer, an imide-based polymer, or a mixture of two or more thereof, but is not limited to these.

[0073] The fluorine-based polymer may include, but is not limited to, a vinylidene fluoride homopolymer obtained by polymerizing only vinylidene fluoride monomer, a copolymer of vinylidene fluoride monomer and one or more selected from trifluoroethylene (TrFE), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), trichloroethylene (TrCE), trichlorofluoroethylene (TCFE), chlorotrifluoroethylene (CTFE), polymethylmethacrylate (PMMA), and polyvinylacetate (PVAc), or a combination of two or more thereof.

[0074] The acrylic polymer may include, for example, an acrylic homopolymer obtained by polymerizing only an acrylic monomer, or a copolymer of an acrylic monomer with another monomer. For example, the acrylic polymer may include, but is not limited to, poly(methylmethacrylate), poly(ethylhexyl acrylate), poly(butylacrylate), poly(acrylonitrile), a copolymer of ethylhexyl acrylate and methyl methacrylate, a copolymer of butyl acrylate and methyl methacrylate, an ethyl acrylate-acrylic acid-N,N-dimethylacrylamide copolymer, an ethyl acrylate-acrylic acid-2-(dimethylamino)ethyl acrylate copolymer, an ethyl acrylate-acrylic acid-N,N-diethylacrylamide copolymer, and an ethyl acrylate-acrylic acid-2-(diethylamino)ethyl acrylate copolymer, or two or more thereof.

[0075] The urethane-based polymer may include, for example, but is not limited to, polyurethane obtained by polymerizing only urethane monomers, a copolymer of a urethane monomer and an acrylic monomer, or two or more thereof.The copolymer of the urethane monomer and the acrylic monomer may have an intermediate structure such as polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, tetrahydrofurane-propylene oxide ring opening copolymer, polybutadiene diol, polydimethylsiloxane diol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexane dimethanol, bisphenol A, etc. Examples of suitable isopropyl alcohols include those synthesized from bisphenol A, hydrogenated bisphenol A, 2,4-toluene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, 1,5-naphthalene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, and bisphenol A propylene oxide-modified diacrylate.

[0076] The epoxy polymer may include, but is not limited to, a polyepoxy polymer obtained by polymerizing only epoxy monomers, a copolymer of an epoxy monomer and an acrylic monomer, or two or more thereof. The copolymer of an epoxy monomer and an acrylic monomer may be selected from the group consisting of copolymers having an intermediate structure composed of a skeleton of bisphenols such as 2-bromohydroquinone, resorcinol, catechol, bisphenol A, bisphenol F, bisphenol AD, and bisphenol S, 4,4'-dihydroxybiphenyl, and bis(4-hydroxyphenyl)ether, and (meth)acrylate oligomers composed of alkyl groups, aryl groups, methylol groups, allyl groups, alicyclic groups, halogens (e.g., tetrabromobisphenol A), and nitro groups.

[0077] The imide-based polymer may include, for example, polyimide.

[0078] In one embodiment of the present invention, the adhesive may be formed by coating one surface of the support with an adhesive forming slurry containing the polymer described above and drying the coating and drying of the slurry, for example, but not limited to, the coating and drying of the slurry may be performed by known methods, but is not limited to, the coating and drying of the slurry may be performed by known methods.

[0079] In one embodiment of the present invention, the electrolyte membrane is not particularly limited as long as it can be used in an all-solid-state battery.

[0080] In one embodiment of the present invention, the electrolyte membrane may be a film-type electrolyte membrane containing a solid electrolyte, and may further contain a binder material, which is an adhesive polymer, as needed.

[0081] The solid electrolyte is not limited to a specific component and may be a polymer-based solid electrolyte, an inorganic-based solid electrolyte, or a mixture thereof. The inorganic-based solid electrolyte may be, for example, a crystalline solid electrolyte, an amorphous solid electrolyte, a glass-ceramic solid electrolyte, or a mixture of two or more thereof. The inorganic-based solid electrolyte may also be, for example, a sulfide-based solid electrolyte, an oxide-based solid electrolyte, or a mixture thereof.

[0082] In one embodiment of the present invention, the polymer solid electrolyte may be, for example, a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, polyagitation lysine, polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, a polymer containing an ionically dissociable group, or a mixture of two or more of these.

[0083] In one embodiment of the present invention, the solid electrolyte may include, for example, a sulfide-based solid electrolyte containing a sulfur component. The sulfide-based solid electrolyte is not particularly limited, and any known sulfide-based material used in the battery field may be used. The sulfide-based material may be a commercially available product, or may be produced by crystallizing an amorphous sulfide-based material. For example, the sulfide-based solid electrolyte may be a crystalline sulfide-based solid electrolyte, an amorphous sulfide-based solid electrolyte, or a mixture of two or more of these. Examples of usable complex compounds include sulfur-halogen compounds, sulfur-germanium compounds, and sulfur-silicon compounds. Specific examples include sulfides such as SiS2, GeS2, and B2S3. The solid electrolyte may also include a compound to which Li3PO4, a halogen, a halogen compound, or a mixture of two or more of these compounds is added. The sulfide-based solid electrolyte is preferably a crystalline sulfide-based solid electrolyte, an amorphous sulfide-based solid electrolyte, or a mixture of two or more of these compounds. -4 Any material capable of realizing lithium ion conductivity of S / cm or more can be used.

[0084] Representative examples include Li6PS5Cl (LPSCl), Thio-LISICON (Li 3.25 Ge 0.25 P 0.75 S4), Li2S-P2S5-LiCl, Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li2S-P2S5, Li3PS4, Li7P3S 11 , LiI-Li2S-B2S3, Li3PO4-Li2S-SiS2, LiPO4-Li2S-SiS, Li 10 GeP2S 12 , Li 9.54 Si 1.74 P 1.44 S 11.7 C 10.3 , Li7P3S 11 , or two or more of these, but are not limited to these.

[0085] In another embodiment of the present invention, the solid electrolyte is, for example, LiN, LISICON (Li (3+x) Ge x V (1-x) O4, 0 <x<1)、LIPON(Li3PO 4-x N x ), Thio-LISICON(Li 3.25 Ge 0.25 P 0.75 S4), Li2O-Al2O3-TiO2-P2O5 (LATP), or two or more thereof.

[0086] The binder material is used to bind the solid electrolyte, and non-limiting examples thereof include vinylidene fluoride homopolymer (PVDF), poly(vinylidene fluoride-hexafluoropropylene) (poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(vinylidene fluoride-chlorotrifluoroethylene) (poly(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE), poly(vinylidene fluoride-tetrafluoroethylene) (poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-TFE), poly(vinylidene fluoride-trichloroethylene) (poly(vinylidene fluoride-co-trichloroethylene) PVDF-TCE), acrylic polymer, styrene-butadiene copolymer, poly(acrylic acid) acid), poly(methylmethacrylate), poly(butylacrylate), poly(acrylonitrile), poly(vinylpyrrolidone), poly(vinylalcohol), poly(vinylacetate), poly(ethylene-co-vinyl acetate), poly(ethylene oxide), poly(arylate), cellulose acetate, cellulose acetate butyrate, cellulose acetate propionatepropionate, cyanoethyl pullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, or two or more thereof.

[0087] In the present invention, the electrode part includes a current collector and an active material layer disposed on at least one surface of the current collector. The active material layer may include, for example, an electrode active material and a binder that binds the electrode active material, and may further include a conductive material as needed.

[0088] The current collector serves as a path for transferring electrons from the outside or receiving electrons from the active material to the outside so that an electrochemical reaction occurs in the active material in the electrode portion, and may be appropriately selected from among conventional current collectors known in the art depending on the type of electrochemical device in which the electrode composite membrane is used, but is not limited thereto.

[0089] The active material is a material involved in an electrode reaction of a battery and may be a positive electrode active material or a negative electrode active material depending on the type of electrode. The positive electrode active material or the negative electrode active material may be appropriately selected from among common materials known in the art depending on the type of electrochemical device in which the electrode composite membrane is used, but is not limited thereto.

[0090] The binder contained in the active material layer is for binding the active material, and may be appropriately selected from among conventional binders known in the art depending on the type of electrochemical device in which the electrode composite membrane is used, but is not limited thereto.

[0091] The conductive material may be appropriately selected from among ordinary materials known in the art, provided that the conductive material has conductivity without causing chemical changes to the electrode portion, but is not limited thereto.

[0092] According to another aspect of the present invention, an electrochemical device is provided.

[0093] According to another aspect of the present invention, an electrochemical device includes an electrode assembly including a positive electrode and a negative electrode, and a case for accommodating the electrode assembly, wherein at least one of the positive electrode and the negative electrode includes the above-described electrode composite membrane.

[0094] The case may be any commonly used battery case, and is not particularly limited in shape depending on the intended use of the battery. For example, the case may be a cylindrical can, a square can, a pouch, or a coin.

[0095] In one embodiment of the present invention, the electrochemical device may be a lithium secondary battery. Specifically, once the electrode composite film is completed, it can be housed in a case, injected with an electrolyte, and sealed in a conventional manner to manufacture a lithium secondary battery.

[0096] In one embodiment of the present invention, the electrochemical device may be an all-solid-state battery. In the all-solid-state battery, the components other than the electrode composite film may be appropriately selected from among those commonly known in the art, and are not particularly limited.

[0097] The present invention will be described in more detail below with reference to examples. However, the following examples are for illustrative purposes only and the scope of the present invention is not limited to these examples.

[0098] [Manufacturing electrode composite membrane] Example 1 First, a film (100 mm thick) made of cellulose nonwoven fabric cut to a size of 3 cm x 3 cm was prepared as a support. Then, a 5 μm thick adhesive was formed by applying and drying a slurry for forming adhesive joints, which was made by dissolving a PVDF binder in an N-methyl-2-pyrrolidone (NMP) solvent, to one surface of the support.

[0099] The electrode plate was prepared as follows: On a 2 cm x 2 cm piece of aluminum foil (12 μm), a nickel-cobalt-manganese oxide-based LiNi 0.8 Co 0.1 Mn 0.1 An electrode (total thickness 100 μm) was prepared containing O2, carbon black as a conductive material, PVDF as a binder, and ajirodite-based Li6PS5Cl as a solid electrolyte in a weight ratio of 78:1:1:20. A 50 μm-thick, 3 cm x 3 cm polypropylene film was then cut into a hole the size of the electrode (2 cm x 2 cm), and a reinforcing material was placed around the side of the electrode. Referring to Figure 2B, the reinforcing material was placed so that its top edge was aligned with the top of the electrode. The resulting electrode plate was the same size (3 cm x 3 cm) as the support.

[0100] The electrolyte membrane was prepared by dissolving a sulfide-based solid electrolyte and a binder in anisole solvent at a ratio of 95:5, coating the slurry on a release film, and then drying.

[0101] The electrode plate and the electrolyte membrane were sequentially stacked on the adhesive portion so that the current collector in the electrode plate was in surface contact with the adhesive portion, and the stacked result was isostatically pressed at a pressure of 500 MPa to prepare an electrode composite membrane having a structure of [support / adhesive portion / electrode plate (reinforcement-electrode portion) / electrolyte membrane].

[0102] Comparative Example 1 As the electrode plate, only the electrode part was used without using a reinforcing material part, and the electrode part and the electrolyte membrane were laminated without using a support or adhesive part, and then pressed under the same conditions as in Example 1 to prepare an electrode composite membrane having an [electrode part / electrolyte membrane] configuration.

[0103] Comparative Example 2 As the electrode plate, only the electrode part was used without using a reinforcing material part, and the support, electrode part, and electrolyte membrane were laminated without using any adhesive part, and then pressed under the same conditions as in Example 1 to prepare an electrode composite membrane having a [support / electrode part / electrolyte membrane] configuration.

[0104] Comparative Example 3 An electrode composite membrane having a structure of [electrode plate (reinforcement material-electrode part) / electrolyte membrane] was prepared in the same manner as in Example 1, except that the support and adhesive part were not provided.

[0105] Comparative Example 4 An electrode composite membrane having a structure of [support / electrode plate (reinforcement material-electrode part) / electrolyte membrane] was prepared in the same manner as in Example 1, except that no adhesive part was provided.

[0106] [Evaluation of adhesive strength with electrolyte membrane] The degree of detachment between the electrolyte membrane and the electrode plate of Example 1 and Comparative Examples 1 to 4 produced above was visually observed to evaluate the adhesive strength.

[0107] FIG. 6 shows a photograph of the appearance of the electrode composite membrane of Example 1, FIG. 7 shows a photograph of the appearance of the electrode composite membrane of Comparative Example 1, and FIG. 8 shows a photograph of the appearance of the electrode composite membrane of Comparative Example 3.

[0108] As can be seen in Figure 6, in Example 1, the electrolyte membrane and the electrode plate were bonded together over the entire area without detachment. On the other hand, as can be seen in Figure 7, in Comparative Example 1, the electrolyte membrane was completely detached from the electrode plate, which only had an electrode portion. Furthermore, as can be seen in Figure 8, in Comparative Example 3, even if the electrode plate was provided with a reinforcing material, the absence of a support structure meant that the electrolyte membrane still detached from the outer edge of the electrode plate.

[0109] Although photographs of the appearances of Comparative Examples 2 and 4 are not shown, it was confirmed that because the electrode plates were not attached to the support, curling still occurred at the outer edges of the electrode plates even after pressure application, which caused the electrolyte membrane to detach.

[0110] The present invention has been described above with reference to the embodiments and drawings. However, a person having ordinary knowledge in the field to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0111] 1: Electrode composite membrane 10: Electrode plate 101: Electrode part 102: Reinforcement part 20: Electrolyte membrane 30:Support 40: Adhesive part

Claims

1. an electrode plate including an electrode portion and a reinforcing material portion; an electrolyte membrane disposed on one surface of the electrode plate; a support disposed on the other surface of the electrode plate; an adhesive portion disposed on at least a portion of the facing portions of the electrode plate and the support, the electrode portion includes a current collector and an active material layer disposed on at least one surface of the current collector, the electrolyte membrane is in contact with at least a portion of the active material layer and is in close contact with the electrode portion and the reinforcing material portion without being separated therefrom; the reinforcing material portion has the same thickness as the electrode portion, is disposed on the side surface of the electrode portion at a predetermined interval so as to surround a part of the side surface of the electrode portion, and is in surface contact with the side surface of the electrode portion without being spaced apart from the side surface of the electrode portion; An electrode composite membrane, wherein the reinforcing material portion and the electrode portion are the same height on the electrolyte membrane side.

2. An electrode plate including an electrode portion and a reinforcing material portion; an electrolyte membrane disposed on one surface of the electrode plate; a support disposed on the other surface of the electrode plate; an adhesive portion disposed on at least a portion of the facing portions of the electrode plate and the support; the electrode portion includes a current collector and an active material layer disposed on at least one surface of the current collector, the electrolyte membrane is in contact with at least a portion of the active material layer and is in close contact with the electrode portion and the reinforcing material portion without being separated therefrom; the reinforcing material portion has a thickness thinner than a thickness of the electrode portion, is arranged so as to surround the entire periphery or at least a part of the periphery of the side surface portion of the electrode portion, and is in surface contact with the side surface portion of the electrode portion without being spaced apart from it; An electrode composite membrane, wherein the reinforcing material portion and the electrode portion are the same height on the electrolyte membrane side.

3. 3. The electrode composite membrane according to claim 1, wherein the electrolyte membrane is disposed so as to cover the entire surface of one surface of the electrode plate.

4. 3. The electrode composite membrane according to claim 1, wherein the reinforcing material portion is arranged around the side surface of the electrode portion at a predetermined interval so as to surround only a portion of the side surface of the electrode portion, and the area around which the reinforcing material portion is arranged is 50% or more of the entire circumference of the side surface of the electrode portion.

5. 3. The electrode composite membrane according to claim 1, wherein the support is disposed so as to cover the entire surface of one surface of the electrode plate.

6. 3. The electrode composite membrane according to claim 1, wherein the adhesive portion is disposed over the entire area of ​​the facing portions of the electrode plate and the support.

7. 3. The electrode composite membrane according to claim 1, wherein the reinforcing material portion contains a polyolefin polymer.

8. 3. The electrode composite membrane according to claim 1, wherein the adhesive portion contains a fluorine-based polymer, an acrylic-based polymer, a urethane-based polymer, an epoxy-based polymer, an imide-based polymer, or a mixture of two or more of these.

9. 3. The electrode composite membrane according to claim 1, wherein the electrolyte membrane is a film-like electrolyte membrane containing a solid electrolyte.

10. an electrode assembly including a positive electrode and a negative electrode; and a case for housing the electrode assembly; 3. An electrochemical element, wherein at least one of the positive electrode and the negative electrode is the electrode composite membrane according to claim 1.

11. The electrochemical device according to claim 10, wherein the electrochemical device is a lithium secondary battery.

12. The electrochemical device according to claim 10, wherein the electrochemical device is an all-solid-state battery.

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