Jig for evaluating a battery cell

Abstract

The present invention relates to a jig for evaluating a battery cell, wherein the jig for evaluating a battery cell comprises: a first plate on which a battery cell to be evaluated is placed; and a second plate located on the opposite side of the surface where the battery cell and the first plate come into contact, and which moves in the thickness direction to press the battery cell, wherein at least one of the first plate and the second plate has a thermally conductive elastic layer formed on the surface facing the battery cell.

Description

Technology Field

[0001] The present invention relates to a jig for evaluating battery cells. Background Technology

[0003] Recently, rechargeable secondary batteries are being widely used as an energy source for wireless mobile devices. Furthermore, secondary batteries are attracting attention as an energy source for electric vehicles and hybrid electric vehicles, which are being proposed as solutions to address air pollution caused by conventional gasoline and diesel vehicles that use fossil fuels. Consequently, the types of applications utilizing secondary batteries are becoming highly diversified due to their advantages, and it is expected that secondary batteries will be applied to a wider range of fields and products in the future than they are today.

[0004] These secondary batteries are classified into lithium-ion batteries, lithium-ion polymer batteries, and lithium-polymer batteries depending on the composition of the electrodes and electrolytes; among these, the use of lithium-ion polymer batteries is increasing due to their low risk of electrolyte leakage and ease of manufacturing. Generally, secondary batteries are classified according to the shape of the battery case into cylindrical and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet. The electrode assembly housed in the battery case is a power generation element capable of charging and discharging, consisting of a positive electrode, a negative electrode, and a separator structure interposed between the positive and negative electrodes. It is further classified into a jelly-roll type, which is wound with a separator interposed between long sheet-type positive and negative electrodes coated with active material, and a stack type, in which multiple positive and negative electrodes of a predetermined size are sequentially stacked with a separator interposed between them.

[0005] These electrodes can be manufactured by forming an electrode active material layer by applying an electrode slurry containing an electrode active material and a solvent onto a current collector, followed by drying and rolling. Recently, as interest in environmental issues has grown, the demand base for high-capacity batteries has expanded due to the growth of the market for devices employing high-capacity batteries, such as electric vehicles and hybrid electric vehicles, which can replace fossil fuel-using vehicles like gasoline and diesel vehicles that are one of the main causes of air pollution. Consequently, there is a need for high-capacity electrode designs for the manufacture of lithium secondary batteries that have high energy density, high output, and high discharge voltage as power sources for these devices.

[0006] Meanwhile, in order to prevent defects from occurring, the battery cell manufactured in this way undergoes a process of evaluating charge / discharge performance, safety performance, and dimensions, and during this process, the battery cell is fastened to a specific type of jig for fixing the battery cell.

[0007] Figure 1 is a schematic diagram showing the structure of a conventional battery cell evaluation jig.

[0008] Referring to FIG. 1, a conventional battery cell evaluation jig (1) is composed of a lower plate (10) that is located at the bottom of the battery cell (40) and supports the battery cell (40), and an upper plate (20) that presses the battery cell (40) from the top of the battery cell (40). These plates may be made of a metal material, for example, aluminum. Meanwhile, the battery cell (40) has a structure in which an electrode lead (42) is drawn out to the outside of the battery case (41).

[0009] Meanwhile, during the evaluation process of a battery cell, the process of measuring the temperature of the battery cell can generally be performed. At this time, a temperature sensor is installed on a jig to measure the temperature of the battery cell. For example, if the temperature sensor is installed on the outer surface of the upper plate, an air gap is formed between the plate and the battery cell due to the numerous irregularities formed on the surface of the upper plate and the battery cell, so the temperature of the battery cell is not fully transmitted to the temperature sensor.

[0010] Therefore, in the conventional case, as shown in Fig. 1, a temperature sensor (30) was installed between the upper plate (20) and the battery cell (40). However, in this case, it was difficult to pressurize the battery cell, the temperature sensor could be damaged due to the pressurization, and there was a problem that the temperature sensor had to be connected to the battery cell every time the battery cell was replaced.

[0011] Therefore, there is a need to develop a battery cell evaluation jig capable of solving the aforementioned problems. Prior art literature

[0013] Korean Patent Publication No. 10-2018-0106673 The problem to be solved

[0014] The present invention was devised to solve the above-mentioned problem and aims to provide a battery cell evaluation jig that can measure the temperature of a battery cell more efficiently and easily by measuring the temperature on the opposite side of the surface where the plate and the battery cell come into contact. means of solving the problem

[0016] A jig for evaluating a battery cell according to one embodiment of the present invention comprises: a first plate on which a battery cell to be evaluated is placed; and a second plate located on a surface opposite to the surface where the battery cell and the first plate are in contact, and which moves in the thickness direction to press the battery cell, wherein at least one of the first plate and the second plate has a thermally conductive elastic layer formed on a surface facing the battery cell.

[0017] In a specific example, the thermally conductive elastic layer may be formed on the surface where the second plate contacts the battery cell.

[0018] In another example, the battery cell evaluation jig according to the present invention may further include a temperature sensor located on the opposite side of the surface on which the thermally conductive elastic layer is formed.

[0019] In a specific example, the thermally conductive elastic layer may include a polymer matrix and a thermally conductive filler dispersed within the polymer matrix.

[0020] In another example, the thermally conductive elastic layer may be a pad or film comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix.

[0021] At this time, the battery cell evaluation jig according to the present invention further includes a thermally conductive adhesive layer formed between the first plate or the second plate and the thermally conductive elastic layer.

[0022] In another example, the thermally conductive elastic layer may be a composition comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix, which is coated on a first plate or a second plate.

[0023] In a specific example, the polymer matrix may be one or more selected from the group comprising silicone resin, urethane resin, epoxy resin, polyester resin, and acrylic resin.

[0024] In a specific example, the thermally conductive filler may be a metal particle or one or more ceramic particles selected from the group comprising SiO2, ZrO2, Al2O3, MgO, ZnO, Fe2O3, Fe3O4, Y2O3, TiO2, SiC, Si3N4, TiB, BN, and AlN.

[0025] In a specific example, the thermally conductive filler may be one or more carbon particles selected from the group including carbon black, artificial graphite, natural graphite, carbon nanotubes, and graphene.

[0026] In another example, the thermally conductive elastic layer may have a structure in which multiple layers of different hardnesses are stacked.

[0027] The above thermally conductive elastic layer may have a structure in which a high-hardness layer with relatively high hardness is interposed between low-hardness layers with relatively low hardness.

[0028] The thickness of the above thermally conductive elastic layer may be 1 to 30% of the thickness of the battery cell to be evaluated.

[0029] In addition, the battery cell evaluation jig according to the present invention may further include a charging / discharging unit for charging and discharging the battery cell to be evaluated. Effects of the invention

[0031] The present invention enables uniform pressure on a battery cell by forming a thermally conductive elastic layer with excellent thermal conductivity and elasticity between a plate constituting a jig and a battery cell. In addition, since the formation of an air gap between the plate and the battery cell can be prevented, accurate temperature measurement is possible even when measuring the temperature of the battery cell on the opposite side of the contact surface between the plate and the battery cell. Furthermore, since the temperature of the battery cell can be measured on the opposite side of the contact surface between the plate and the battery cell, the temperature of the battery cell can be measured more efficiently and easily. Brief explanation of the drawing

[0033] Figure 1 is a schematic diagram showing the structure of a conventional battery cell evaluation jig. FIG. 2 is a schematic diagram showing the structure of a battery cell evaluation jig according to a first embodiment of the present invention. FIG. 3 is a schematic diagram showing the structure of a battery cell evaluation jig according to a second embodiment of the present invention. FIG. 4 is a schematic diagram showing the structure of a battery cell evaluation jig according to a third embodiment of the present invention. FIG. 5 is a schematic diagram showing the structure of a battery cell evaluation jig according to the fourth embodiment of the present invention. Specific details for implementing the invention

[0034] The present invention will be described in detail below. Prior to this, terms or words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor may appropriately define the concepts of terms to best describe their invention, they must be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0035] In this application, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only cases where it is "immediately above" the other part, but also cases where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only cases where it is "immediately below" the other part, but also cases where there is another part in between. Additionally, in this application, being placed "on" may include cases where it is placed on the lower part as well as on the upper part.

[0037] The present invention will be described in detail below.

[0038] A jig for evaluating a battery cell according to one embodiment of the present invention comprises: a first plate on which a battery cell to be evaluated is placed; and a second plate located on a surface opposite to the surface where the battery cell and the first plate are in contact, and which moves in the thickness direction to press the battery cell, wherein at least one of the first plate and the second plate has a thermally conductive elastic layer formed on a surface facing the battery cell.

[0039] As mentioned above, in the conventional method, a temperature sensor was installed between the upper plate and the battery cell to measure the temperature of the battery cell; however, this method had the problems of making it difficult to pressurize the battery cell, potentially damaging the temperature sensor due to the pressurization, and requiring the temperature sensor to be connected between the plate and the battery cell every time the battery cell was replaced.

[0040] The present invention enables uniform pressure on a battery cell by forming a thermally conductive elastic layer with excellent thermal conductivity and elasticity between a plate constituting a jig and a battery cell. In addition, since the formation of an air gap between the plate and the battery cell can be prevented, accurate temperature measurement is possible even when measuring the temperature of the battery cell on the opposite side of the contact surface between the plate and the battery cell. Furthermore, since the temperature of the battery cell can be measured on the opposite side of the contact surface between the plate and the battery cell, the temperature of the battery cell can be measured more efficiently and easily.

[0042] The battery cell evaluation jig according to the present invention will be described in detail below.

[0043] In the present invention, the first plate provides a space for mounting a battery cell, and the second plate performs the role of pressing the battery cell. In a general case, the first plate is positioned on the ground to support the battery cell from below, and the second plate is positioned on the top of the battery cell to press the battery cell toward the ground. Additionally, the first plate and the second plate may be composed of a metal material with excellent thermal conductivity for the accuracy and ease of temperature measurement, as described below, and may be composed of, for example, aluminum.

[0044] The above thermally conductive elastic layer is formed on at least one of the first plate and the second plate, and is formed on the surface of the first plate and the second plate facing the battery cell.

[0045] In a specific example, the thermally conductive elastic layer may be formed on the surface where the second plate contacts the battery cell. As described above, in a general case, the first plate is located on the ground and serves to support the battery cell from below; therefore, if the thermally conductive plate is formed on the upper surface of the first plate, there is an inconvenience in having to place a temperature sensor between the first plate and the ground to measure the temperature of the battery cell. Accordingly, the thermally conductive elastic layer is formed on the second plate that performs the pressurization of the battery cell, and is formed on the surface where the second plate contacts the battery cell.

[0046] In another example, the battery cell evaluation jig according to the present invention further includes a temperature sensor located on the opposite side of the surface on which the thermally conductive elastic layer is formed. Since the plate and the thermally conductive elastic layer are composed of a material with excellent thermal conductivity, heat generated from the battery cell can be transferred to the temperature sensor via the thermally conductive elastic layer and the plate, thereby allowing the temperature sensor to indirectly measure the temperature of the battery cell. By placing the temperature sensor on the opposite side of the surface where the plate and the battery cell come into contact, the possibility of damage to the temperature sensor during the measurement process is reduced, and the configuration of the device can be simplified, allowing the temperature of the battery cell to be measured efficiently and easily.

[0047] Meanwhile, since the above-mentioned thermally conductive elastic layer exhibits high thermal conductivity and heat dissipation characteristics, it is possible to allow heat generated from the battery cell to reach the temperature sensor via the plate. In addition, since the thermally conductive elastic layer exhibits high elasticity, it can prevent an air gap that may form between the plate and the battery cell when the battery cell is pressurized. Through this, the heat generated from the battery cell can be fully transferred to the temperature sensor.

[0048] Specifically, the thermally conductive elastic layer comprises a polymer matrix and a thermally conductive filler dispersed within the polymer matrix.

[0049] Specifically, the polymer matrix may be one or more selected from the group including silicone resins, urethane resins, epoxy resins, polyester resins, and acrylic resins, provided that it has excellent thermal conductivity and elasticity, although there are no specific restrictions on the type thereof. In this case, to improve the elasticity of the thermally conductive elastic layer, a rubber or elastomer component capable of exhibiting elasticity may be added. Specific details regarding other polymer matrices are known to those skilled in the art, so a detailed explanation is omitted.

[0050] In addition, the thermally conductive filler may have a thermal conductivity of 10 to 400 W / mK, more specifically 50 to 350 W / mK, more specifically 100 to 300 W / mK. As such a thermally conductive filler, it may be one or more selected from the group comprising metal particles, Al2O3, MgO, ZnO, Fe2O3, Fe3O4, Y2O3, TiO2, SiC, Si3N4, TiB, BN, and AlN. As the metal particles, metal materials with excellent thermal conductivity such as gold, silver, iron, aluminum, and nickel may be used.

[0051] In addition, the thermally conductive filler may be one or more carbon particles selected from the group including black, artificial graphite, natural graphite, carbon nanotubes, and graphene. The thermally conductive filler may use any one of metal particles, ceramic particles, and carbon particles, or may use a mixture of two or more.

[0052] The above thermally conductive filler may have a particle diameter of 5 to 40 μm, and more specifically, 10 to 30 μm. When the particle diameter of the above thermally conductive filler is within the above range, excellent dispersibility and thermal conductivity may be exhibited. If the particle diameter of the thermally conductive filler exceeds the above range, particle dispersibility may be reduced, and if the particle diameter of the thermally conductive filler is below the above range, the thermal resistance of the thermally conductive filler increases, which may result in inaccurate temperature measurement of the battery cell.

[0053] Meanwhile, the thermal conductivity of the above-mentioned thermally conductive elastic layer is not particularly limited as long as it can transfer heat generated in the battery cell with minimal loss, but it may be 10 to 50 W / mK, specifically 20 to 50 W / mK, and specifically 30 to 50 W / mK. The above-mentioned thermal conductivity may be a value measured according to ASTM D5470 or ISO 22007-2 standards. In the present invention, the method of setting the thermal conductivity of the thermally conductive elastic layer to the above range is not particularly limited and can be controlled through the type of polymer matrix and thermally conductive filler and the content of the thermally conductive filler.

[0054] In addition, the thermally conductive elastic layer may have a Shore 00 hardness of 5 to 40, specifically 15 to 30. The Shore 00 hardness may be measured according to ASTM D2240 standards. When the Shore 00 hardness is within the above range, it can be stably supported on the plate while preventing gaps formed by fine irregularities between the plate and the battery cell surface. The Shore 00 hardness can be controlled through the type of polymer matrix and the content of the thermally conductive filler included in the polymer matrix; generally, the harder the higher the content of the thermally conductive filler, the lower the hardness of silicone-based resins among the polymer matrices compared to resins such as epoxy or urethane.

[0055] To this end, the content of the thermally conductive filler in the polymer matrix can be appropriately adjusted for the elasticity and thermal conductivity of the thermally conductive elastic layer as described above, but, for example, the weight ratio of the polymer matrix to the thermally conductive filler may be in the range of 4:1 to 1:4 or 3:1 to 1:3.

[0056] In addition, the above thermally conductive elastic layer may further include additives such as flame retardants and curing agents.

[0057] In one example, the thermally conductive elastic layer may be a pad or film comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix. When the thermally conductive elastic layer is in the form of a pad or film, it is easy to attach and detach from the plate, which has the advantage of being easy to replace if the thermally conductive elastic layer is damaged. In addition, since the thermally conductive elastic layer can be manufactured in a separate process and then attached to the plate, the manufacturing of the jig becomes simpler.

[0058] When the above thermally conductive elastic layer is in the form of a pad or film, a composition for constituting the thermally conductive elastic layer can be manufactured by molding and curing. Molding methods may include extrusion molding, press molding, and comma coating molding, but the molding method is not limited thereto.

[0059] At this time, in order to attach the thermally conductive elastic layer in the shape of the pad or film to the plate, the battery cell evaluation jig according to the present invention may further include a thermally conductive adhesive layer formed between the first plate or the second plate and the thermally conductive elastic layer. As described above, when the second plate is located between the temperature sensor and the thermally conductive elastic layer, the thermally conductive adhesive layer may be formed between the second plate and the thermally conductive elastic layer.

[0060] The above-mentioned thermally conductive adhesive layer may be in the form in which a thermally conductive filler is dispersed in a polymer component used as a conventional adhesive. The polymer component used as the adhesive is not subject to any particular restrictions on its type as long as it exhibits excellent thermal conductivity and excellent adhesive strength, but, for example, it may be one or more selected from the group including acrylic resins, silicone resins, urethane resins, and epoxy resins. In addition, the thermally conductive filler may be the same as that used in the thermally conductive elastic layer. The composition of the above-mentioned thermally conductive adhesive layer may be appropriately designed according to the pad or film.

[0061] The thickness of the thermally conductive adhesive layer may be 1 to 50 µm, specifically 5 to 45 µm, more specifically 10 to 40 µm. When the thickness of the thermally conductive adhesive layer is within the above range

[0062] The above-mentioned thermally conductive adhesive layer can be easily manufactured using methods known in the art. For example, the above-mentioned thermally conductive adhesive layer can be manufactured by UV curing a photosensitive composition containing a thermally conductive material. Alternatively, commercially available products may be used as is.

[0063] In another example, the thermally conductive elastic layer may be a composition comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix, which is coated on a first plate or a second plate.

[0064] In this case, the thermally conductive elastic layer can be prepared by dispersing and stirring a mixture containing a polymer matrix and a thermally conductive filler in a solvent to form a slurry, and then coating the slurry onto a plate.

[0065] Likewise, the thermally conductive elastic layer can be cured after being coated on a plate.

[0066] Meanwhile, the thickness of the thermally conductive elastic layer is not subject to any particular limitation as long as it can transfer heat generated in the battery cell while preventing gaps caused by fine irregularities, but, for example, it may be 1 to 30% of the thickness of the battery cell being evaluated, more specifically 5 to 25%, and even more specifically 10 to 20%. However, if the thickness is excessively small, it is difficult to prevent gaps caused by fine irregularities on the plate and the surface of the battery cell, and if the thickness is excessively thick, the length of the heat transfer path becomes long, so the measured temperature may be inaccurate due to heat loss in the middle.

[0067] In another example, the thermally conductive elastic layer may have a structure in which multiple layers with different hardnesses are stacked. In this case, heat transfer from the battery cell and the elimination of the gap between the battery cell and the plate can be performed more effectively by adjusting the hardness differently depending on the position of the layers.

[0068] In a specific example, the thermally conductive elastic layer may have a structure in which a high-hardness layer with relatively high hardness is interposed between low-hardness layers with relatively low hardness. In this case, since the portion where the plate or battery cell contacts the thermally conductive elastic layer exhibits relatively low hardness, gaps caused by fine irregularities can be effectively prevented. Meanwhile, the high-hardness layer formed in the middle may be configured to maintain its thickness and shape while having high thermal conductivity. At this time, the low-hardness layer may have a Shore hardness of 00 in the range described above. Additionally, the high-hardness layer may have a Shore hardness of 50 to 100, specifically 60 to 80.

[0069] To exhibit the aforementioned differences in hardness and thermal conductivity, the content of the thermally conductive filler included in the high-hardness layer may be configured to be greater than the content of the thermally conductive layer included in the low-hardness layer. Through this, the thermal conductivity within the high-hardness layer can be further increased.

[0070] In addition, even if the thermally conductive elastic layer is composed of multiple layers, the sum of the total thicknesses of each layer can be configured as described above. In this case, the high-hardness layer and the low-hardness layer may be fixed using a separate adhesive or may be fixed through lamination. Alternatively, the thermally conductive elastic layer may be formed by sequentially coating the compositions constituting each layer onto a plate.

[0072] Meanwhile, the battery cell evaluation jig according to the present invention may further include a charging / discharging unit for charging and discharging the battery cell to be evaluated. In this case, the battery cell can be heated while adjusting the charging / discharging conditions, and the resulting temperature can be measured through the temperature sensor.

[0073] The present invention enables uniform pressure on a battery cell by forming a thermally conductive elastic layer with excellent thermal conductivity and elasticity between a plate constituting a jig and a battery cell. In addition, since the formation of an air gap between the plate and the battery cell can be prevented, accurate temperature measurement is possible even when measuring the temperature of the battery cell on the opposite side of the contact surface between the plate and the battery cell. Furthermore, since the temperature of the battery cell can be measured on the opposite side of the contact surface between the plate and the battery cell, the temperature of the battery cell can be measured more efficiently and easily.

[0075] Meanwhile, the battery cell to be measured above may have a structure in which an electrode assembly in which a positive electrode, a separator, and a negative electrode are sequentially stacked, and an electrolyte are housed within a battery case.

[0076] At this time, the anode and cathode can be manufactured by applying an electrode slurry containing an anode active material and a cathode active material to an anode current collector, respectively, and then drying and rolling. The electrode slurry may further include a conductive material and a binder, etc., in addition to the active material.

[0077] In the present invention, the positive current collector is generally made with a thickness of 3 to 500 μm. Such a positive current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and 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. The current collector may also form fine irregularities on its surface to increase the adhesion of the positive active material, and various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics are possible.

[0078] In the case of the negative electrode current collector, it 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, titanium, silver, etc., and aluminum-cadmium alloy may be used. In addition, similar to the positive electrode current collector, fine irregularities may be formed on the surface to strengthen the bonding strength of the negative electrode active material, and it may be used in various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics.

[0079] In the present invention, the positive electrode active material is a material capable of causing an electrochemical reaction, and is a lithium transition metal oxide comprising two or more transition metals, for example, a layered compound such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2) substituted with one or more transition metals; lithium manganese oxide substituted with one or more transition metals; and the chemical formula LiNi 1-y M yLithium nickel-based oxide represented by O2 (wherein M = Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn, or Ga and contains one or more of the above elements, 0.01≤y≤0.7); Li 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, Li 1+z Ni 0.4 Mn 0.4 Co 0.2 Li, like O2, etc. 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A e A lithium nickel cobalt manganese composite oxide represented by (where -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2, 0≤e≤0.2, b+c+d<1, M = Al, Mg, Cr, Ti, Si or Y, and A = F, P or Cl); chemical formula Li 1+x M 1-y M' y PO 4-z X z Examples include olivine-based lithium metal phosphates expressed as (where M = transition metal, preferably Fe, Mn, Co, or Ni, M' = Al, Mg, or Ti, X = F, S, or N, and -0.5≤x≤+0.5, 0≤y≤0.5, 0≤z≤0.1), but are not limited to these.

[0080] In addition, the negative electrode active material is carbon, for example, non-graphitizable carbon, graphite-based carbon, etc.; 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, Bi2O5등의 금속 산화물; 폴리아세틸렌 등의 도전성 고분자; Li-Co-Ni 계 재료 등을 사용할 수 있다.

[0081] The above conductive material may typically be added in an amount of 1 to 30 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 fiber or metal fiber; 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.

[0082] The above binder is a component that assists in the bonding of the active material and the conductive material, and in the bonding to the current collector, and is typically added in an amount of 1 to 30 weight percent based on the total weight of the mixture containing the positive 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 butadiene rubber, fluororubber, and various copolymers.

[0083] Meanwhile, the above-mentioned separator is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 μm, and the thickness is generally 5 to 300 μm. For example, olefin-based polymers such as chemically resistant and hydrophobic polypropylene; sheets or nonwoven fabrics made of glass fibers or polyethylene are used as such separators.

[0084] Meanwhile, the electrolyte may consist of an organic solvent and a lithium salt, and the organic solvent may be a non-aqueous organic solvent.

[0085] As the above-mentioned non-aqueous organic solvent, for example, aprotic organic solvents such as N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butylolactone, 1,2-dimethoxyethane, tetrahydroxyfranc, 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolone, formamide, dimethylformamide, dioxolone, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphate triester, trimethoxymethane, dioxolone derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ether, methyl propionate, ethyl propionate, etc. may be used.

[0086] The above lithium salt is a substance that dissolves well in the above-mentioned non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO4, LiBF4, LiB 10 Cl 10 LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, (CF3SO2)2NLi, lithium chloroborane, lithium lower aliphatic carboxylate, lithium tetraphenylborate, imide, etc. may be used.

[0087] In addition, for the purpose of improving charge / discharge characteristics and flame retardancy, the electrolyte may be further enriched with, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphate triamide, nitrobenzene derivative, sulfur, quinone imine dye, N-substituted oxazolidinone, N,N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride, etc. In some cases, to impart non-flammability, halogen-containing solvents such as carbon tetrachloride and trifluoroethylene may be further enriched, carbon dioxide may be further enriched to improve high-temperature storage characteristics, and FEC (Fluoro-Ethylene Carbonate), PRS (Propene Sultone), etc.

[0088] Meanwhile, the above-mentioned battery case is not particularly limited as long as it is used as an exterior material for packaging the battery, and cylindrical, prismatic, or pouch-type cases may be used, but specifically, a pouch-type battery case may be used. A pouch-type battery case is typically made of an aluminum laminate sheet and may consist of an inner sealant layer for sealing, a metal layer to prevent the penetration of substances, and an outer resin layer forming the outermost part of the case.

[0090] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0092] (First embodiment)

[0093] FIG. 2 is a schematic diagram showing the structure of a battery cell evaluation jig according to a first embodiment of the present invention.

[0094] Referring to FIG. 2, a battery cell evaluation jig (100) according to the present invention comprises: a first plate (110) on which a battery cell (140) to be evaluated is placed; and a second plate (120) located on the opposite side of the surface where the battery cell (140) and the first plate (110) come into contact, and which moves in the thickness direction to press the battery cell. Specifically, in FIG. 2, the first plate (110) supports the battery cell (140) on the lower surface of the battery cell (140), and the second plate (120) presses the battery cell (140) toward the first plate (110) from the upper surface of the battery cell (140). Meanwhile, the battery cell (140) is a pouch-type battery cell, having a structure in which electrode leads (142) are drawn out on both sides of a battery case (141).

[0095] Additionally, the battery cell evaluation jig (100) is provided with a thermally conductive elastic layer (130) to transfer heat generated from the battery cell (140) and to prevent a gap between the surface of the battery cell (140) and the plates (110, 120). The thermally conductive elastic layer (130) is formed on at least one of the first plate (110) and the second plate (120), and is formed on the surface of the first plate (110) and the second plate (120) facing the battery cell (140). In FIG. 2, the thermally conductive elastic layer (130) is shown formed on the second plate (120), and is formed on the surface facing the second plate (120) and the battery cell (140).

[0096] The above thermally conductive elastic layer (130) may be a pad or film comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix, or may be coated with a composition comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix.

[0098] (Second embodiment)

[0099] FIG. 3 is a schematic diagram showing the structure of a battery cell evaluation jig according to a second embodiment of the present invention.

[0100] Referring to FIG. 3, a battery cell evaluation jig (200) according to the present invention comprises: a first plate (210) on which a battery cell (240) to be evaluated is placed; and a second plate (220) located on the opposite side of the surface where the battery cell (240) and the first plate (210) come into contact, and which moves in the thickness direction to press the battery cell. Specifically, in FIG. 3, the first plate (210) supports the battery cell (240) on the lower surface of the battery cell (240), and the second plate (220) presses the battery cell (240) toward the first plate (210) from the upper surface of the battery cell (240). Meanwhile, the battery cell (240) is a pouch-type battery cell, having a structure in which electrode leads (242) are drawn out on both sides of a battery case (241).

[0101] Additionally, the battery cell evaluation jig (200) is provided with a thermally conductive elastic layer (230) to transfer heat generated from the battery cell (240) and to prevent a gap between the surface of the battery cell (240) and the plates (210, 220). The thermally conductive elastic layer (230) is formed on at least one of the first plate (210) and the second plate (220), and is formed on the surface of the first plate (210) and the second plate (220) facing the battery cell (140). In FIG. 2, the thermally conductive elastic layer (230) is shown formed on the second plate (120), and is formed on the surface facing the second plate (220) and the battery cell (240). The thermally conductive elastic layer (230) can be configured in the same way as the first embodiment described above.

[0102] Additionally, the battery cell evaluation jig (200) includes a temperature sensor (250). The temperature sensor (250) is located on the opposite side of the surface where the thermally conductive elastic layer (230) is formed. Fig. 3 illustrates that the temperature sensor (250) is located on one side of the second plate (220), but on the opposite side of the surface where the thermally conductive elastic layer (230) is formed. Through this, heat generated from the battery cell (240) can be transferred to the temperature sensor (250) via the thermally conductive elastic layer (230) and the second plate (220), and the temperature sensor (250) can measure the temperature of the battery cell (240) from this.

[0104] (Third embodiment)

[0105] FIG. 4 is a schematic diagram showing the structure of a battery cell evaluation jig according to a third embodiment of the present invention.

[0106] Referring to FIG. 4, the battery cell evaluation jig (300) according to the present invention comprises: a first plate (310) on which a battery cell (340) to be evaluated is placed; and a second plate (320) located on the opposite side of the surface where the battery cell (340) and the first plate (310) come into contact, and which moves in the thickness direction to press the battery cell. Specifically, in FIG. 4, the first plate (310) supports the battery cell (340) on the lower surface of the battery cell (340), and the second plate (320) presses the battery cell (340) toward the first plate (310) from the upper surface of the battery cell (340). Meanwhile, the battery cell (340) is a pouch-type battery cell, having a structure in which electrode leads (342) are drawn out on both sides of a battery case (341).

[0107] Additionally, the battery cell evaluation jig (300) is provided with a thermally conductive elastic layer (330) to transfer heat generated from the battery cell (340) and to prevent a gap between the surface of the battery cell (340) and the plates (310, 320). The thermally conductive elastic layer (330) is formed on at least one of the first plate (310) and the second plate (320), and is formed on the surface of the first plate (310) and the second plate (320) facing the battery cell (340). In FIG. 4, the thermally conductive elastic layer (330) is shown formed on the second plate (320), and is formed on the surface facing the second plate (320) and the battery cell (340).

[0108] At this time, the thermally conductive elastic layer (330) is a pad or film comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix. In this way, a thermally conductive adhesive layer (360) may be formed between the second plate (320) and the thermally conductive elastic layer (330) to attach the thermally conductive elastic layer (330) in the form of a pad or film to the second plate (320).

[0109] In addition, in this case, a temperature sensor may also be located on the second plate.

[0111] (Fourth embodiment)

[0112] FIG. 5 is a schematic diagram showing the structure of a battery cell evaluation jig according to the fourth embodiment of the present invention.

[0113] Referring to FIG. 5, a battery cell evaluation jig (400) according to the present invention comprises: a first plate (410) on which a battery cell (440) to be evaluated is placed; and a second plate (420) located on the opposite side of the surface where the battery cell (440) and the first plate (410) come into contact, and which moves in the thickness direction to press the battery cell. Specifically, in FIG. 5, the first plate (410) supports the battery cell (440) on the lower surface of the battery cell (440), and the second plate (420) presses the battery cell (440) toward the first plate (410) from the upper surface of the battery cell (440). Meanwhile, the battery cell (440) is a pouch-type battery cell, having a structure in which electrode leads (442) are drawn out on both sides of a battery case (441).

[0114] Additionally, the battery cell evaluation jig (400) is provided with a thermally conductive elastic layer (430) to transfer heat generated from the battery cell (440) and to prevent a gap between the surface of the battery cell (440) and the plates (410, 420). The thermally conductive elastic layer (430) is formed on at least one of the first plate (410) and the second plate (420), and is formed on the surface of the first plate (410) and the second plate (420) facing the battery cell (440). In FIG. 5, the thermally conductive elastic layer (430) is shown formed on the second plate (420), and is formed on the surface facing the second plate (420) and the battery cell (440).

[0115] At this time, the thermally conductive elastic layer (430) may be composed of multiple layers with different hardness. Specifically, referring to FIG. 5, the thermally conductive elastic layer (430) has a structure in which a high-hardness layer (431) with relatively high hardness is interposed between a low-hardness layer (432) with relatively low hardness.

[0116] In this case, the portion where the second plate (420) or battery cell (440) and the thermally conductive elastic layer (430) come into contact exhibits relatively low hardness, so gaps caused by fine irregularities can be effectively prevented. Meanwhile, the high-hardness layer (431) formed in the middle can be configured to maintain its thickness and shape and exhibit high thermal conductivity.

[0117] In addition, in this case, a temperature sensor may also be located on the second plate.

[0119] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the drawings disclosed in this invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these drawings. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0121] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back have been used in this specification, these terms are used merely for convenience of explanation, and it is obvious that they may vary depending on the location of the object or the position of the observer. Explanation of the symbols

[0123] 1, 100, 200, 300, 400: Battery cell evaluation jig 10: Lower plate 20: Upper plate 30, 250: Temperature sensor 40, 140, 240, 340, 440: Battery cell 41, 141, 241, 341, 441: Battery case 42, 142, 242, 342, 442: Electrode leads 110, 210, 310, 410: First plate 120, 220, 320, 420: Second plate 130, 230, 330, 430: Thermally conductive elastic layer 360: Adhesive layer 431: High hardness layer 432: Low hardness layer

Claims

Claim 1 A battery cell evaluation jig comprising: a first plate on which a battery cell to be evaluated is placed; and a second plate located on a surface opposite to the surface where the battery cell and the first plate contact each other, and which moves in the thickness direction to press the battery cell, wherein at least one of the first plate and the second plate has a thermally conductive elastic layer formed on a surface facing the battery cell, and a temperature sensor located on a surface opposite to the surface where the thermally conductive elastic layer is formed. Claim 2 In claim 1, the thermally conductive elastic layer is formed on the surface where the second plate contacts the battery cell, forming a battery cell evaluation jig. Claim 3 delete Claim 4 In claim 1, the thermally conductive elastic layer comprises a polymer matrix and a thermally conductive filler dispersed within the polymer matrix, forming a battery cell evaluation jig. Claim 5 In claim 4, the thermally conductive elastic layer is a pad or film comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix, a jig for evaluating a battery cell. Claim 6 A battery cell evaluation jig according to claim 5, further comprising a thermally conductive adhesive layer formed between the first plate or the second plate and the thermally conductive elastic layer. Claim 7 A battery cell evaluation jig according to claim 4, wherein the thermally conductive elastic layer is a composition comprising a polymer matrix and a thermally conductive filler dispersed within the polymer matrix, which is coated on a first plate or a second plate. Claim 8 A battery cell evaluation jig according to claim 4, wherein the polymer matrix is ​​one or more selected from the group comprising silicone-based resin, urethane-based resin, epoxy-based resin, polyester-based resin, and acrylic-based resin. Claim 9 A battery cell evaluation jig according to claim 4, wherein the thermally conductive filler is a metal particle or one or more ceramic particles selected from the group comprising SiO2, ZrO2, Al2O3, MgO, ZnO, Fe2O3, Fe3O4, Y2O3, TiO2, SiC, Si3N4, TiB, BN, and AlN. Claim 10 In claim 4, the thermally conductive filler is a battery cell evaluation jig in which one or more carbon particles selected from the group comprising carbon black, artificial graphite, natural graphite, carbon nanotubes, and graphene. Claim 11 In claim 1, the thermally conductive elastic layer is a battery cell evaluation jig having a structure in which a plurality of layers with different hardnesses are stacked. Claim 12 In claim 11, the above-mentioned thermally conductive elastic layer is a jig for evaluating a battery cell having a structure in which a high-hardness layer with relatively high hardness is interposed between a low-hardness layer with relatively low hardness. Claim 13 A battery cell evaluation jig according to claim 1, wherein the thickness of the thermally conductive elastic layer is 1 to 30% of the thickness of the battery cell to be evaluated. Claim 14 A battery cell evaluation jig according to claim 1, further comprising a charging / discharging unit for charging and discharging the battery cell to be evaluated.

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