Electrode Assembly Provided With a Venting Gas Adsorption Unit and Battery Cell Including It

Abstract

The present invention relates to an electrode assembly equipped with a venting gas adsorption member and a battery cell including the same, comprising: a first electrode current collector having a first coating layer coated with a first electrode active material on one side and a first uncoated portion not coated with the first electrode active material formed thereon; a second electrode current collector having a second coating layer coated with a second electrode active material on one side; and a first separator positioned between the first electrode current collector and the second electrode current collector such that one side faces the first coating layer and the first uncoated portion of the first electrode current collector, and the other side faces the second coating layer of the second electrode current collector, wherein a first gas adsorption member is provided on one side of the first separator at a position corresponding to the first uncoated portion.

Description

Technology Field

[0001] The present invention relates to an electrode assembly equipped with a venting gas adsorption member and a battery cell including the same. Specifically, the invention relates to an electrode assembly equipped with a venting gas adsorption member capable of adsorbing venting gas when gas is generated within the battery cell, and a battery cell including the same. Background Technology

[0002] Recently, the demand for rechargeable batteries capable of storing generated electrical energy is increasing due to air pollution caused by the use of fossil fuels and the development of alternative energy sources resulting from energy depletion. Rechargeable rechargeable batteries are being closely utilized in daily life, such as in mobile devices, electric vehicles, and hybrid electric vehicles.

[0003] Rechargeable batteries, which serve as an indispensable energy source for various electronic devices in modern society, are seeing increased capacity requirements due to the growing usage and complexity of mobile devices and the development of electric vehicles. While multiple battery cells are arranged in small devices to meet user demand, vehicles utilize battery modules that electrically connect multiple battery cells, or battery packs equipped with multiple such modules.

[0004] Meanwhile, due to aging and charging / discharging, gas can be generated as the battery cell reacts with the electrolyte internally, and this gas can accumulate inside the cell, causing problems such as capacity degradation and lithium precipitation.

[0005] FIG. 1 is a cross-sectional view showing an electrode assembly according to the prior art. As shown in FIG. 1, the electrode assembly (10) according to the prior art comprises an anode (20) composed of an anode current collector (21) and an anode active material layer (22), a cathode (30) composed of a cathode current collector (31) and a cathode active material layer (33), and a coating layer (40) located between the anode (20) and the cathode (30).

[0006] As illustrated in FIG. 1, in an electrode assembly according to the prior art, the coating layer (40) contains gas-adsorbing inorganic particles and can adsorb venting gas generated inside the battery cell.

[0007] However, the coating layer (40) is interposed between the positive electrode (20) and the negative electrode (30), which increases the volume and causes a decrease in energy density, resulting in a problem where the performance of the battery is degraded. Prior art literature

[0008] Korean Patent Publication No. 2019-0142965 The problem to be solved

[0009] The present invention aims to solve the above-mentioned problems by providing an electrode assembly capable of absorbing venting gas generated inside a battery cell without increasing the volume of the electrode assembly, and a battery cell including the same. means of solving the problem

[0010] To achieve the above objectives, an electrode assembly equipped with a venting gas adsorption member according to the present invention comprises: a first electrode current collector (100) having a first coating layer (110) coated with a first electrode active material on one side and a first uncoated portion (120) not coated with the first electrode active material; and a second electrode current collector (200) having a second coating layer (210) coated with a second electrode active material on one side. The apparatus comprises a first separator (300) positioned between the first electrode current collector (100) and the second electrode current collector (200), wherein one side faces the first coating layer (110) and the first uncoated portion (120) of the first electrode current collector (100), and the other side faces the second coating layer (210) of the second electrode current collector (200); wherein a first gas adsorption member (310) is provided on one side of the first separator (300) at a position corresponding to the first uncoated portion (120).

[0011] In addition, in the electrode assembly of the present invention, a second uncoated portion (220) in which the second electrode active material is not coated is further formed on one side of the second electrode current collector (200), and a first gas adsorption member (310) is further provided on the other side of the first separator (300) at a position corresponding to the second uncoated portion (120).

[0012] In addition, in the electrode assembly of the present invention, the height of the first gas adsorption member (310) is less than or equal to the height of the first coating layer (110).

[0013] In addition, in the electrode assembly of the present invention, the width of the first gas adsorption member (310) is less than or equal to the width of the first uncoated portion (120).

[0014] In addition, in the electrode assembly of the present invention, the first gas adsorption member (310) is characterized by being one or more selected from carbon fiber, porous carbon material, porous metal oxide, porous gel and zeolite.

[0015] In addition, the electrode assembly of the present invention is characterized in that a third coating layer (130) coated with a first electrode active material and a third uncoated portion (240) not coated with a first electrode active material are further formed on the other side of the first electrode current collector (100).

[0016] In addition, the electrode assembly of the present invention is characterized in that a fourth coating layer (230) coated with a second electrode active material and a fourth uncoated portion (240) not coated with a second electrode active material are further formed on the other side of the second electrode current collector (200).

[0017] In addition, in the electrode assembly of the present invention, a second separator (400) is positioned on the upper side of the other side of the first electrode current collector (100) and on the lower side of the other side of the second electrode current collector (200), respectively, and the second separator (400) is further provided with a second gas adsorption member (410) at a position corresponding to the third uncoated portion (140) and the fourth uncoated portion (240).

[0018] In addition, in the electrode assembly of the present invention, the height of the second gas adsorption member (410) is characterized as being less than or equal to the height of the third coating layer (130) and the fourth coating layer.

[0019] In addition, in the electrode assembly of the present invention, the width of the second gas adsorption member (410) is less than or equal to the width of the third uncoated portion (140) and the fourth uncoated portion.

[0020] In addition, in the electrode assembly of the present invention, the first electrode current collector (100) is one of stainless steel, aluminum, nickel, titanium, and calcined carbon, and the second electrode current collector (200) is one of copper, stainless steel, aluminum, aluminum-cadmium alloy, nickel, titanium, and calcined carbon.

[0021] In addition, the present invention may be a battery cell comprising an electrode assembly having the aforementioned features.

[0022] In addition, the present invention may be a battery module comprising the aforementioned battery cell. Effects of the invention

[0023] As described above, according to the electrode assembly equipped with a venting gas adsorption member and the battery cell including the same according to the present invention, an uncoated portion is provided near the coating layer of the electrode current collector, and a gas adsorption member capable of adsorbing generated gas is located in this uncoated portion, thereby preventing degradation of battery performance and improving battery stability.

[0024] In addition, according to the electrode assembly equipped with a venting gas adsorption member and the battery cell including the same, since the gas adsorption member is provided at a height below the coating layer, there is an advantage that damage caused by gas can be prevented without increasing the volume of the electrode assembly.

[0025] Furthermore, according to the electrode assembly equipped with a venting gas adsorption member and the battery cell including the same, the gas adsorption member formed on the separator is located in the uncoated portion, thereby preventing the position of the electrode and the separator from shifting due to vibration and shock, etc., which is an advantage. Brief explanation of the drawing

[0026] FIG. 1 is a cross-sectional view showing an electrode according to the prior art. FIG. 2 is a perspective view showing an electrode assembly according to a preferred first embodiment of the present invention. Figure 3 is an exploded cross-sectional view taken by cutting vertically along the line A-A' of Figure 2. Figure 4 is a cross-sectional view showing a vertical cut along the line A-A' of Figure 2. FIG. 5 is a perspective view showing an electrode assembly according to a preferred second embodiment of the present invention. Figure 6 is an exploded cross-sectional view taken by cutting vertically along the line A-A' of Figure 5. Figure 7 is a cross-sectional view showing a vertical cut along the line A-A' of Figure 5. Specific details for implementing the invention

[0027] Embodiments that enable a person skilled in the art to easily implement the present invention are described in detail below with reference to the attached drawings. However, in describing the operating principles of preferred embodiments of the present invention in detail, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the present invention, such detailed description is omitted.

[0028] In addition, the same reference numerals are used for parts having similar functions and operations throughout the drawings. Throughout the specification, when a part is described as being connected to another part, this includes not only cases where they are directly connected, but also cases where they are indirectly connected with other elements in between. Furthermore, unless specifically stated otherwise, the inclusion of a certain component does not exclude other components but implies that additional components may be included.

[0029] Hereinafter, an electrode assembly equipped with a venting gas adsorption member according to the present invention will be described with reference to the attached drawings.

[0030] FIG. 2 is a perspective view showing an electrode assembly according to a preferred first embodiment of the present invention, FIG. 3 is an exploded cross-sectional view taken vertically along line A-A' of FIG. 2, and FIG. 4 is a cross-sectional view taken vertically along line A-A' of FIG. 2.

[0031] Referring to FIGS. 2 to 4, an electrode assembly according to a preferred embodiment of the present invention comprises a first electrode current collector (100), a second electrode current collector (200), and a separator (300).

[0032] The first electrode current collector (100) is in the shape of a film and is configured to include a first coating layer (110) and a first uncoated portion (120), and acts as an intermediate medium for supplying electrons provided from an external wire to the electrode active material, or conversely, acts as a carrier for collecting electrons generated as a result of an electrode reaction and flowing them to the external wire.

[0033] In addition, the first electrode current collector (100) is an important constituent material for realizing the shape of the actual electrode plate, and may be an anode current collector.

[0034] The positive current collector can generally have a thickness of 3 to 500 μm. It is not particularly limited as long as it has high conductivity without causing chemical changes in the battery; for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., may be used. In addition, various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics are possible, or fine irregularities may be formed on the surface to increase the adhesion of the positive active material.

[0035] The first coating layer (110) may be formed on one side of the electrode current collector in a mixed form of an electrode active material, a conductive material, and a binder, and the electrode active material may be a positive active material.

[0036] The positive electrode active material is a layered compound such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or a compound substituted with a transition metal or higher; chemical formula Li 1+x Mn 2-x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2, etc.; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, Cu2V2O7, etc.; chemical formula LiNi 1-xNi-site type lithium nickel oxide represented by MxO2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); chemical formula LiMn 2-x Lithium manganese complex oxides represented by MxO2 (where M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01–0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which part of the Li in the chemical formula is substituted with alkaline earth metal ions; disulfide compounds; Fe2(MoO4)3, LiNi x Mn 2-x You can use O4(0.01 ≤ x ≤ 0.6), etc.

[0037] The first uncoated portion (120) is a portion on one side of the first electrode current collector (100) where the electrode active material is not coated.

[0038] Next, the second electrode current collector (200) is configured in the form of a film, including a second coating layer (210) and a second uncoated portion (220), and acts as an intermediate medium for supplying electrons provided from an external wire to the electrode active material, or conversely, acts as a carrier for collecting electrons generated as a result of an electrode reaction and flowing them to the external wire.

[0039] In addition, the second electrode current collector (200) is an important constituent material for realizing the shape of the actual electrode plate and may be a negative electrode current collector.

[0040] The negative electrode current collector is generally made with a thickness of 3 to 500 μm. Such a negative electrode current collector is not particularly limited as long as it is conductive without causing chemical changes in the battery, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface treated with carbon, nickel, carbon, silver, etc., and aluminum-cadmium alloy may be used. In addition, similar to the positive electrode current collector described above, the negative electrode current collector may form fine irregularities on its surface to strengthen the bonding force of the negative electrode active material, and may be used in various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics.

[0041] The second coating layer (210) may be formed on one side of the electrode current collector in a mixed form of an electrode active material, a conductive material, and a binder, and the electrode active material may be a negative electrode active material.

[0042] The negative electrode active material is, for example, Li x Fe2O3(0≤x≤1), Li x WO2(0≤x≤1), Sn x Me 1-x Me y O z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, Group 1, 2, and 3 elements of the periodic table, halogens; 0 <x≤1; 1≤y≤3; 1≤z≤8) 등의 금속 복합 산화물; 리튬 금속; 리튬 합금; 규소계 합금; 주석계 합금; SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5등의 금속 산화물; 폴리아세틸렌 등의 도전성 고분자; Li-Co-Ni 계 재료 등이 사용될 수 있다.

[0043] The second uncoated portion (220) is a portion on one side of the second electrode current collector (200) where the electrode active material is not coated.

[0044] Meanwhile, conductive materials and binders may be mixed into the positive or negative active materials, and fillers may be added as needed.

[0045] The conductive material is typically added in an amount of 1 to 50 weight percent based on the total weight of the mixture containing the electrode active material. Such conductive material is not particularly limited as long as it is conductive without causing chemical changes in the battery, and examples may be used, such as graphite, such as natural graphite or artificial graphite; carbon black, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black; conductive fibers, such as carbon fibers or metal fibers; metal powders, such as carbon fluoride, aluminum, or nickel powder; conductive whiskey, such as zinc oxide or potassium titanate; conductive metal oxides, such as titanium oxide; or conductive materials, such as polyphenylene derivatives.

[0046] A binder is a component that assists in the bonding of the electrode active material and the conductive material, as well as the bonding to the current collector, and is typically added in an amount of 1 to 50 weight percent based on the total weight of the mixture containing the electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butylene rubber, fluororubber, and various copolymers.

[0047] In addition, an electrode tab protruding a predetermined length in one direction may be formed on the first electrode current collector (100) and the second electrode current collector (200).

[0048] Here, when the positive tab and the negative tab are formed in the same direction, it is called a unidirectional electrode assembly, and when the positive tab is formed in one direction and the negative tab is formed in the other direction, it is called a bidirectional electrode assembly.

[0049] Next, the first separator (300) is in the form of a film and is positioned between the first electrode current collector (100) and the second electrode current collector (200) such that one side faces the first coating layer (110) and the first uncoated portion (120) of the first electrode current collector (100), and the other side faces the second coating layer (120) and the second uncoated portion (220) of the second electrode current collector (200).

[0050] This first separator (300) is positioned between the first electrode current collector (100) and the second electrode current collector (200), thereby preventing a short circuit caused by contact between the first electrode current collector (100) and the second electrode current collector (200) and allowing only the movement of lithium ions.

[0051] Here, the first separator (300) is preferably selected from, for example, polyethylene, polypropylene, a polyethylene / polypropylene double layer, a polyethylene / polypropylene / polyethylene triple layer, a polypropylene / polyethylene / polypropylene triple layer, and an organic fiber filter paper, but is not limited thereto.

[0052] On one side of the first separator (300), a first gas adsorption member (310) is provided at a position corresponding to the first uncoated portion (120), and on the other side, a first gas adsorption member (310) is further provided at a position corresponding to the second uncoated portion (222).

[0053] The first gas adsorption member (310) is made of a material capable of adsorbing gas, and has the advantage of preventing performance degradation and improving stability of the battery by absorbing venting gas generated within the battery cell.

[0054] For example, the first gas adsorption member (310) may be one or more of carbon fibers, porous carbon materials, porous metal oxides, porous gels, and zeolites.

[0055] In addition, the height of the first gas adsorption member (310) is less than or equal to the height of the first coating layer (110), and the width of the first gas adsorption member (310) is less than or equal to the width of the first uncoated portion (120), so there is an advantage that damage caused by venting gas can be prevented without affecting the volume change of the electrode assembly.

[0056] In addition, the first gas adsorption member (310) may be integrated with the separator (300) and positioned in close contact with the first uncoated portion (120) and the second uncoated portion (220), thereby having the advantage of preventing the position between the electrode and the separator from shifting due to vibration and shock.

[0057] FIG. 5 is a perspective view showing an electrode assembly according to a preferred second embodiment of the present invention, FIG. 6 is an exploded cross-sectional view taken vertically along line A-A' of FIG. 5, and FIG. 7 is a cross-sectional view taken vertically along line A-A' of FIG. 5.

[0058] Referring to FIGS. 5 to 7, the electrode assembly according to the second embodiment of the present invention is further provided with a second separator (400), and since it is identical to the electrode assembly according to the first embodiment described in FIGS. 2 to 4 except for some configurations of the first electrode current collector (100) and the second electrode current collector (200), the description of the identical configurations will be omitted.

[0059] An electrode assembly according to a second embodiment of the present invention further comprises a third coating layer (130) and a third uncoated portion (140) formed on the other side of a first electrode current collector (100), a fourth coating layer (230) and a fourth uncoated portion (240) formed on the other side of a second electrode current collector (200), and further comprises a pair of second separators (400).

[0060] A third coating layer (130) is formed on the other side of the first electrode current collector (100) and has the same composition as the first coating layer (200) described above, and a third uncoated portion (140) is formed on the other side of the first electrode current collector (100).

[0061] The fourth coating layer (230) is formed on the other side of the second electrode current collector (200) and has the same composition as the second coating layer (210) described above, and the fourth uncoated portion (240) is formed on the other side of the second electrode current collector (200).

[0062] The second separator (400), which is located on the upper side of the other side of the first electrode current collector (100) and the lower side of the other side of the second electrode current collector (200), is provided with a second gas adsorption member (410) at a position corresponding to the third uncoated part (140) and the fourth uncoated part (240).

[0063] The second gas adsorption member (410) is made of a material capable of adsorbing gas and is identical to the first gas adsorption member (310) described above, so a redundant description will be omitted.

[0064] The height of the second gas adsorption member (410) is less than or equal to the height of the third coating layer (130) and the fourth coating layer, and the width of the second gas adsorption member (410) is formed to be less than or equal to the width of the third uncoated portion (140) and the fourth uncoated portion. Therefore, it is possible to absorb venting gas without increasing volume, thereby maintaining battery performance and preventing the precipitation of lithium, which has the advantage of improving stability.

[0065] In addition, the electrode assembly according to the second embodiment is additionally equipped with a second gas adsorption member (410) together with the first gas adsorption member (310), so there is an advantage that the amount of gas that can be adsorbed increases compared to the first embodiment in which only the first gas adsorption member (310) is formed.

[0066] The present invention may be a battery cell comprising the aforementioned electrode assembly. Additionally, the battery cell may be a battery module housing the battery cell, and the battery module may be a device mounted thereon. For example, the device may be an electronic device comprising a large-capacity battery, such as an electric vehicle, a hybrid vehicle, or a plug-in hybrid electric vehicle.

[0067] In addition, the electrode assembly described above in the present invention can be applied to stack-type battery cells, such as pouch-type battery cells and prismatic battery cells, and can also be applied to winding-type battery cells in which the electrode assembly is rolled up, for example, cylindrical battery cells.

[0068] As specific parts of the present invention have been described in detail above, it is obvious to those skilled in the art that such specific descriptions are merely preferred embodiments and do not limit the scope of the invention, and that various changes and modifications are possible within the scope and spirit of the invention, and that such variations and modifications fall within the scope of the appended claims. Explanation of the symbols

[0069] 100 : First electrode current collector 110: First coating layer 120 : 1st Uncoated Section 130 : Third coating layer 140 : 3rd Uncoated Section 200 : Second electrode current collector 210: Second coating layer 220 : 2nd Uncoated Section 230 : 4th coating layer 240 : 4th Uncoated Section 300: First separator 310 : First gas adsorption member 400 : Second separator 410 : Second gas adsorption member

Claims

Claim 1 An electrode assembly comprising: a first electrode current collector having a first coating layer coated with a first electrode active material and a first uncoated portion not coated with the first electrode active material formed on one side; a second electrode current collector having a second coating layer coated with a second electrode active material formed on one side; and a first separator positioned between the first electrode current collector and the second electrode current collector such that one side faces the first coating layer and the first uncoated portion of the first electrode current collector, and the other side faces the second coating layer of the second electrode current collector; wherein a first gas adsorption member is provided on one side of the first separator at a position corresponding to the first uncoated portion. Claim 2 An electrode assembly according to claim 1, wherein a second uncoated portion in which the second electrode active material is not coated is further formed on one side of the second electrode current collector, and a first gas adsorption member is further provided on the other side of the first separator at a position corresponding to the second uncoated portion. Claim 3 An electrode assembly according to claim 1, characterized in that the height of the first gas adsorption member is less than or equal to the height of the first coating layer. Claim 4 An electrode assembly characterized in that, in paragraph 3, the width of the first gas adsorption member is less than or equal to the width of the first uncoated portion. Claim 5 An electrode assembly according to claim 1, wherein the first gas adsorption member is one or more selected from carbon fiber, porous carbon material, porous metal oxide, porous gel, and zeolite. Claim 6 An electrode assembly according to claim 1, characterized in that a third coating layer coated with a first electrode active material and a third uncoated portion not coated with a first electrode active material are further formed on the other side of the first electrode current collector. Claim 7 An electrode assembly according to claim 6, characterized in that a fourth coating layer coated with a second electrode active material and a fourth uncoated portion not coated with a second electrode active material are further formed on the other side of the second electrode current collector. Claim 8 An electrode assembly according to claim 7, wherein a second separator is positioned on the upper side of the other side of the first electrode current collector and on the lower side of the other side of the second electrode current collector, respectively, and a second gas adsorption member is further provided on the second separator at a position corresponding to the third uncoated portion and the fourth uncoated portion. Claim 9 An electrode assembly according to claim 8, characterized in that the height of the second gas adsorption member is less than or equal to the height of the third coating layer and the fourth coating layer. Claim 10 An electrode assembly according to claim 8, characterized in that the width of the second gas adsorption member is less than or equal to the width of the third uncoated portion and the fourth uncoated portion. Claim 11 An electrode assembly according to claim 1, wherein the first electrode current collector is any one of stainless steel, aluminum, nickel, titanium, and calcined carbon, and the second electrode current collector is any one of copper, stainless steel, aluminum, aluminum-cadmium alloy, nickel, titanium, and calcined carbon. Claim 12 A battery cell comprising an electrode assembly described in any one of claims 1 to 11. Claim 13 A battery module comprising the battery cell described in paragraph 12.

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