Electrode for rechargeable battery, electrode assembly, and active material coating device

Abstract

The embodiment of the invention provides an electrode, an electrode assembly and an active material coating device for a rechargeable battery. The electrode includes a substrate, a lower layer formed on the substrate and including a plurality of portions, a pattern layer formed on the lower layer, a filling layer formed on the lower layer and located between the plurality of portions of the pattern layer, and an upper layer formed on the pattern layer and the filling layer.

Description

Technical Field

[0001] Examples of the present disclosure relate to an electrode for a rechargeable battery, an electrode assembly including the electrode, and an active material coating apparatus for manufacturing the electrode. Background Art

[0002] Unlike primary batteries, which are usually charged only once and then discarded once discharged, rechargeable batteries are batteries that are repeatedly charged and discharged. Small capacity rechargeable batteries can be used in portable small electronic devices such as mobile phones, laptop computers, camcorders, etc. Large capacity and high density rechargeable batteries can be used as a power source or energy storage for, for example, driving a motor of a hybrid vehicle or electric vehicle.

[0003] Therefore, as the demand for rechargeable batteries used in various fields increases, the demand for high-performance, high-capacity, and long-life batteries increases.

[0004] Current negative electrodes or anodes of rechargeable batteries use graphite, but although such electrodes have a capacity close to the theoretical capacity (~372 mAh / g), in order to achieve high capacity at a lower loading, it may be advantageous to use a negative electrode active material such as metallic lithium (~3860 mAh / g) or silicon (~4200 mAh / g), for example.

[0005] However, when using active materials to achieve high capacity, many challenges may have to be addressed. Such challenges may include, for example, short circuits due to dendritic growth during charge and discharge of the battery in the case of metallic lithium anodes, or lifetime degradation due to large volume changes (~400%) during charge and discharge of the battery in the case of silicon anodes. Summary of the invention

[0006] Example embodiments of the present disclosure include an electrode for a rechargeable battery, an electrode assembly including the electrode, and an active material coating device for manufacturing the electrode, which can increase battery life while achieving high capacity using an active material containing silicon without deteriorating electrical performance due to volume changes.

[0007] Example embodiments of the present disclosure provide an electrode for a rechargeable battery, the electrode comprising: a substrate; a lower layer formed on the substrate; a pattern layer formed on the lower layer and comprising a plurality of portions (such as a plurality of columns as an example); a filling layer formed on the lower layer and disposed or located between the plurality of portions or columns of the pattern layer; and an upper layer formed on the pattern layer and the filling layer.

[0008] In various examples, the pattern layer may have a larger expansion property than the filling layer, the lower layer, and the upper layer, and the filling layer, the lower layer, and the upper layer may have a relatively smaller expansion property than the pattern layer.

[0009] In other examples, the lower layer, the filling layer, and the upper layer may include a carbon-based active material, and the pattern layer may include a silicon-based active material.

[0010] For example, the filling layer and the upper layer may be made of or include the same active substance.

[0011] In another example, the pattern layer may have a greater viscosity than the filling layer and the upper layer.

[0012] The viscosity of the upper layer and the filling layer may be equal to about 3000±1500 mPas, and the viscosity of the pattern layer may be equal to about 9500±4500 mPas.

[0013] In various examples, portions or columns of the pattern layer may have a long length in one direction.

[0014] In other examples, multiple portions or columns of the pattern layer may be configured or arranged in a matrix.

[0015] Another exemplary embodiment of the present disclosure provides an active material coating device, the active material coating device comprising: a slot die having a first opening, a second opening, and a third opening; a first spacer installed at both sides of the first opening to form a first discharge port; a second spacer installed in the second opening at regular intervals to form a plurality of second discharge ports; and a third spacer installed in the third opening to form a third discharge port. The third spacer comprises a first portion and a second portion, the first portion being located at a position corresponding to one of the plurality of second discharge ports of the second opening, and the second portion being located at a position corresponding to the first spacer.

[0016] For example, the third discharge port may include a first small discharge port located at a position corresponding to the second spacer and a second small discharge port located at a position corresponding to the first discharge port. The first small discharge port and the second small discharge port may be connected to form a single discharge port.

[0017] According to example embodiments of the present disclosure, it is possible to provide an electrode for a rechargeable battery, an electrode assembly including the electrode, and an active material coating device for manufacturing the electrode, the electrode being able to limit or minimize volume expansion while achieving high capacity using a silicon-based active material. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A top plan view of a negative electrode is shown according to an example embodiment of the present disclosure.

[0019] Figure 2 Shown along Figure 1A cross-sectional view taken along line II-II'.

[0020] Figure 3 A top plan view of a negative electrode according to another example embodiment of the present disclosure is shown.

[0021] Figure 4 A method of forming an active material layer according to an example embodiment of the present disclosure is illustrated.

[0022] Figure 5 and Figure 6 Shows Figure 4 A top plan view of a slot die of an active substance coating device shown in FIG.

[0023] Figure 7 A schematic perspective view of a rechargeable battery according to an example embodiment of the present disclosure is shown.

[0024] Figure 8 It is along Figure 7 A cross-sectional view taken along line VIII-VIII'. DETAILED DESCRIPTION

[0025] Examples of the present disclosure are described more fully below with reference to the accompanying drawings in which example embodiments of the invention are shown. As will be appreciated by those skilled in the art, the described example embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. The accompanying drawings and description are to be considered illustrative and not restrictive in nature. Throughout the specification, the same reference numerals represent the same elements.

[0026] When the term "about" or "substantially" is used in conjunction with a numerical value in this specification, it means that the associated numerical value includes a tolerance of ±10% around the stated numerical value. When a range is specified, the range includes all values ​​therebetween in increments such as 0.1%.

[0027] Figure 1 shows a top plan view of a negative electrode according to an example embodiment of the present disclosure, Figure 2 Shown along Figure 1 A cross-sectional view taken along line II-II', Figure 3 A top plan view of a negative electrode according to another example embodiment of the present disclosure is shown.

[0028] like Figure 1 and Figure 2 As shown in FIG. 1 , a negative electrode 700 according to an exemplary embodiment of the present disclosure includes a substrate 710 and a negative active material layer 720 formed on the substrate 710. The negative active material layer 720 may be composed of or include a lower layer 71, an intermediate layer 72, and an upper layer 73.

[0029] The substrate 710 may be any material that does not react with lithium (i.e., any material that does not form an alloy or compound with lithium and is conductive). For example, the substrate 710 may be a metal or an alloy or include a metal or an alloy. The metal may include, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. The substrate 710 may have a shape selected from, for example, a sheet, a foil, a film, a plate, a porous body, a mesoporous body, a body containing through holes, a polygonal ring body, a mesh body, a foam body, and a non-woven fabric, but is not limited thereto, and any form used in the art may be used.

[0030] The negative electrode active material layer 720 may include, for example, a negative electrode active material, a binder, and a selective conductive material. In other examples, the negative electrode active material may include a carbon-based active material or a silicon-based active material.

[0031] The negative active material layer 720 according to an example embodiment of the present disclosure may include a lower layer 71, an intermediate layer 72, and an upper layer 73. The lower layer 71, the upper layer 73, and the intermediate layer 72 may include different negative active materials.

[0032] The lower layer 71 may have a uniform thickness on the entire surface of the substrate 710 , or may be formed to have a uniform thickness on the entire surface of the substrate 710 .

[0033] The lower layer 71 may include a carbon-based active material. The carbon-based active material is a carbon-containing active material basically used for the negative electrode active material layer, and may include crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon may include graphite such as amorphous, flaky, spherical, or fibrous natural graphite or artificial graphite, and examples of amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbon, fired coke, and the like.

[0034] The intermediate layer 72 includes a filling layer 8 filling spaces between portions or columns of the pattern layer 7 .

[0035] Parts or columns of the pattern layer 7 may be in a matrix form and arranged at regular intervals. The plane shape is shown as a quadrilateral shape in the drawings, but is not limited thereto, and may be formed into various shapes such as a circular shape, an elliptical shape, or a polygonal shape such as a pentagonal shape. In addition, the pattern layer 7 may be as Figure 3 As shown in FIG. , it is formed long in one direction.

[0036] The pattern layer 7 may include a silicon-based active material capable of achieving relatively higher capacity than the filling layer 8 , the lower layer 71 , and the upper layer 73 , and may have a relatively high expansion rate compared to other layers of the negative electrode 700 .

[0037] Specifically, the silicon-based active material may include silicon, a silicon-carbon composite, SiO x (0 < x < 2), an Si-Q alloy (Q is an element selected from alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof, but not Si), or a combination thereof, and at least one of the silicon-carbon composite and the Si-Q alloy may be mixed and used with SiO2. The element Q may be selected from Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof.

[0038] For example, the silicon-based active material may include a silicon-carbon composite including silicon particles and a first carbonaceous material. For example, the first carbonaceous material may be crystalline carbon, amorphous carbon, or a combination thereof or include crystalline carbon, amorphous carbon, or a combination thereof. When the silicon-carbon composite is used as the silicon-based active material, stable cycle characteristics can be achieved while achieving a high capacity.

[0039] In the silicon-carbon composite including silicon particles and a first carbonaceous material, the content of the silicon particles may be in the range of, for example, 30 wt% to 70 wt%, or in the range of, for example, 40 wt% to 50 wt%. The content of the first carbonaceous material may be in the range of, for example, 70 wt% to 30 wt%, or in the range of, for example, 50 wt% to 60 wt%. When the contents of the silicon particles and the first carbonaceous material are within the above ranges, the silicon-carbon composite can provide high-capacity characteristics and improved life characteristics.

[0040] Optionally, the silicon-based active material may include a silicon-carbon composite including a core mixed with silicon particles and a second carbonaceous material and a third carbonaceous material surrounding the core. The silicon-carbon composite can achieve a high capacity while improving the capacity retention rate and high-temperature life characteristics of the battery simultaneously or contemporaneously.

[0041] The filling layer 8 may be made of a material having a filling capacity and expansibility relatively smaller than those of the pattern layer 7 or include a material having a filling capacity and expansibility relatively smaller than those of the pattern layer 7, and may be made of, for example, a carbonaceous active material or include, for example, a carbonaceous active material. The filling layer 8 may be made of the same negative electrode active material as the lower layer 71 or include the same negative electrode active material as the lower layer 71.

[0042] The filling layer 8 has a relatively smaller expansion property than the pattern layer 7 and is configured to fill the gaps between the parts or columns of the pattern layer 7, so that at least one part or column of the pattern layer 7 or each part or column is surrounded by the filling layer 8, or the filling layer 8 is located on both sides of each or at least one part or column of the pattern layer 7. Therefore, even if the pattern layer 7 is to expand during charging and discharging, the pattern layer 7 may not expand easily due to the filling layer 8 and thus may maintain its shape. In addition, the filling layer 8 has a smaller expansion property than the pattern layer 7, so there is little change in shape during charging and discharging.

[0043] The upper layer 73 may be formed to have a uniform thickness on substantially the entire surface of the intermediate layer 72 , and may be made of or include the same active material as the lower layer 71 or the filling layer 8 .

[0044] As described above, in example embodiments of the present disclosure, a silicon-based active material having a high expansion property is used to achieve high capacity while reducing or substantially preventing expansion of the silicon-based active material during charge and discharge.

[0045] Meanwhile, the lower layer 71 , the middle layer 72 , and the upper layer 73 further include a binder and a conductive material as well as a negative electrode active material.

[0046] The binder may be used to adhere the negative active material particles to each other and also reliably adhere the negative active material to a substrate which may be, for example, a current collector. As the binder, a non-aqueous binder, an aqueous binder, or a combination thereof may be used.

[0047] The non-aqueous binder may include, for example, ethylene propylene copolymer, polyacrylonitrile, polystyrene, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or any combination thereof.

[0048] The aqueous adhesive may include styrene-butadiene rubber, acrylated styrene-butadiene rubber (ABR), acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluororubber, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyepichlorohydrin, polyphosphazene, ethylene propylene diene copolymer, polyvinyl pyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, or any combination thereof.

[0049] When an aqueous binder is used as a binder, a thickener (i.e., a cellulose compound capable of imparting viscosity) may be further included. As the cellulose compound, at least one of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose or an alkali metal salt thereof may be mixed and used. Na, K or Li may be used as the alkali metal. The amount of the cellulose compound may be, for example, in the range of 0.1 to 3 parts by weight based on 100 parts by weight of the negative electrode active material.

[0050] The conductive material is used to impart conductivity to the electrode, and may be any material or include any material as long as the conductive material does not cause chemical changes in the battery. Examples of the conductive material may include carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, and carbon fiber), metal powders (such as copper, nickel, aluminum, and silver), metal-based materials (such as metal fibers), conductive polymers (such as polyphenylene derivatives), or any mixture thereof.

[0051] The lower layer, the middle layer, and the upper layer forming the negative electrode active material layer according to the exemplary embodiment of the present disclosure may be formed simultaneously or concurrently, which will be referred to as Figures 4 to 6 Detailed description.

[0052] Figure 4 A method of forming an active material layer according to an exemplary embodiment of the present disclosure is shown. Figure 5 and Figure 6 Shows Figure 4 A top plan view of a slot die of an active substance coating device shown in FIG.

[0053] like Figure 4 As shown in , the active material coating apparatus according to an exemplary embodiment of the present disclosure includes a slot die 500 that forms a negative active material layer 720 by coating an active material onto a substrate 710 supplied in a continuous manner via a roller 51 .

[0054] The slot die 500 according to an example embodiment of the present disclosure is connected to an external slurry supply source (not shown) to receive active material slurry from the slurry supply source and discharges the active material slurry through a discharge port of the slot die 500 to form a negative active material layer 720 .

[0055] Reference Figure 2 and Figure 5 , discharge ports 510 , 520 , and 530 are formed in the slot mold 500 , and the discharge ports 510 , 520 , and 530 may include a first discharge port 510 for forming the lower layer 71 , a second discharge port 520 for forming the middle layer 72 , and a third discharge port 530 for forming the upper layer 73 .

[0056] Therefore, in the exemplary embodiment of the present disclosure, the active material is discharged simultaneously or concurrently through the discharge ports 510, 520 and 530 of the slot die 500, so that the lower layer 71, the middle layer 72 and the upper layer 73 can be formed simultaneously or concurrently. Since the three layers 71, 72 and 73 are formed together substantially at the same time, the portions at the boundaries of the respective layers can be mixed with each other due to gravity, density or pressure. That is, the two layers 71 and 72 can be mixed with each other at the boundary therebetween, or the two layers 72 and 73 can be mixed with each other at the boundary therebetween.

[0057] Reference Figure 2 , Figure 5 and Figure 6 , the slot die 500 has three openings S1, S2, and S3, and the first spacer P1, the second spacer P2, and the third spacer P3 can be installed in the openings S1, S2, and S3, respectively. Therefore, the shapes of the first discharge port 510, the second discharge port 520, and the third discharge port 530 can be determined by the form in which the first spacer P1, the second spacer P2, and the third spacer P3 are installed.

[0058] The corresponding spacers P1, P2 and P3 can be installed in the openings S1, S2 and S3 according to the shape of the active material layer to be formed, and a portion of the openings S1, S2 and S3 can be blocked according to the shape of each layer or at least one layer of the active material layer to be formed to determine the shape of the discharge ports 510, 520 and 530.

[0059] For example, the first spacers P1 are respectively disposed on both sides of the first opening S1, and the opening portion between the first spacers P1 becomes the first discharge port 510. In order to form the lower layer 71 with a uniform thickness on the substrate, the first discharge port 510 may have a long shape in one direction. That is, the width of the first spacer P1 may be adjusted so that the length L of the first discharge port 510 is the same or substantially the same as the width D of the lower layer 71.

[0060] The second discharge port 520 is used to form the pattern layer 7 of the middle layer 72, and in order to form a portion or column of the pattern layer 7 configured or arranged at regular intervals, a plurality of second spacers P2 may be provided at regular intervals in the second opening S2. Therefore, the pattern layer 7 may be continuously formed on the lower layer 71, and due to the presence of the plurality of second discharge ports 520 at regular intervals, a plurality of portions or columns of the pattern layer 7 may be formed, wherein each portion or column of the pattern layer 7 corresponds to the second discharge port 520.

[0061] In this case, when the supply time of the active material slurry supplied to the second discharge port 520 is controlled, a plurality of portions or columns of the pattern layer 7 may be formed at regular lengths and intervals rather than in a continuous manner. Figure 1 The matrix configuration is shown in .

[0062] The third discharge port 530 is used to form the filling layer 8 of the middle layer 72 together with the upper layer 73, and the third discharge port 530 includes a first small discharge port SS1 for discharging the filling layer 8 to fill the gaps between the parts or columns of the pattern layer 7 and a second small discharge port SS2 for discharging the upper layer 73 to cover the entire middle layer 72, similar to the lower layer 71. The first small discharge port SS1 may be staggered with the second discharge port 520, and the second small discharge port SS2 may have a long shape in one direction like the first discharge port 510. The first small discharge port SS1 and the second small discharge port SS2 may be connected to each other to form a single discharge port.

[0063] In order to form the first and second small discharge ports SS1 and SS2 in different shapes, the third partition member P3 includes at least a first portion PS1 and a second portion PS2.

[0064] The first portion PS1 of the third spacer P3 is located at a position vertically corresponding to the second discharge port 520 and between the first small discharge ports SS1, and the second portion PS2 of the third spacer P3 is located on both sides of the second small discharge port SS2. Therefore, the length L of the second small discharge port SS2 and the length L of the first discharge port 510 may be the same or substantially the same.

[0065] In this case, the thickness DS1 of the first discharge port 510 and the thickness DS2 of the second portion PS2 of the third discharge port 530 may be different according to the thicknesses of the lower layer 71 and the upper layer 73 to be formed.

[0066] Meanwhile, since the viscosity of the active material slurry used to form the pattern layer 7 can maintain a constant pattern shape after coating, the pattern layer 7 can have a higher viscosity than the viscosity used to form the upper layer 73 and the filling layer 8. The filling layer 8 can have a higher fluidity than the pattern layer 7 because the filling layer 8 is configured to easily fill the space between the parts or columns of the pattern layer 7 that have been formed, and can have a relatively lower viscosity than the pattern layer 7. When the solid fractions of the upper layer 73, the lower layer 71, the filling layer 8, and the pattern layer 7 are identically 50%, the viscosity of the upper layer 73 and the filling layer 8 can be equal to about 3000±1500mPas, the viscosity of the pattern layer 7 can be equal to about 9500±4500mPas, and the viscosity of the lower layer 71 can be equal to about 4000±1000mPas.

[0067] The viscosity of each layer or at least one layer can be adjusted by the adhesive content, so the adhesive content of the lower layer 71 can be relatively high, so its viscosity can also be high. In addition, the adhesive content of the upper layer 73 and the filling layer 8 can be relatively low, so their viscosity can also be low.

[0068] Figure 7 1 shows a schematic perspective view of a rechargeable battery 1000 according to an example embodiment of the present disclosure, Figure 8 It is along Figure 7 A cross-sectional view taken along line VIII-VIII'.

[0069] Here, the rechargeable battery 1000 according to the embodiment is described as an example in which a wound (jelly roll) electrode assembly is placed in a prismatic shell, but the examples of the present disclosure are not limited to this, and electrode assemblies such as stacked type, stacked and folded type, and Z-folded type can be applied as a battery in a shell that is one of a cylindrical type, a pouch type, and a coin type.

[0070] like Figure 7 and Figure 8 As shown in , a rechargeable battery 1000 according to example embodiments includes an electrode assembly 10 , a case 27 accommodating the electrode assembly 10 , and a cap assembly 30 mounted in an opening of the case 27 .

[0071] The electrode assembly 10 includes stacked (eg, sequentially stacked) positive electrodes 11 and negative electrodes 12 and a separator 13 between the positive and negative electrodes 11 and 12. The separator 13 is located between the positive and negative electrodes 11 and 12 and insulates the positive and negative electrodes 11 and 12 from each other.

[0072] The electrode assembly 10 may be a jelly roll type in which it is wound around a winding axis X and then flattened, with the separator 13 interposed between the positive electrode (cathode or first electrode) 11 and the negative electrode (anode or second electrode) 12 .

[0073] The separator 13 may be a polymer film through which lithium ions can pass or include a polymer film through which lithium ions can pass, and polyethylene, polypropylene, or polyvinylidene fluoride may be used. A multilayer film of two or more layers thereof may be used as the separator 13. A mixed multilayer film such as a polyethylene / polypropylene double-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, or a polypropylene / polyethylene / polypropylene three-layer separator may be used as the separator 13.

[0074] The positive electrode 11 includes an electrode active region and an electrode uncoated region, and the electrode active region includes a substrate formed of or including a thin metal foil and a positive electrode active material layer, and the positive electrode active material may be on the substrate. The electrode uncoated region is a region where the positive electrode active material layer is not formed and the substrate is exposed, and may be a portion extending from the substrate of the electrode active region.

[0075] The electrode uncoated area DA2 of the positive electrode 11 may be located at one side end of the positive electrode 11 along the length direction of the positive electrode 11 .

[0076] The substrate of the positive electrode 11 may be aluminum or include aluminum, and a compound capable of reversibly inserting and extracting lithium (lithiated inserting compound) may be used as a positive electrode active material. For example, one or more of a composite oxide of lithium and a metal selected from, for example, cobalt, manganese, nickel, and a combination thereof may be used. In the positive electrode, the content of the positive electrode active material may be about 90 wt% to 98 wt% based on the total weight of the positive electrode active material layer.

[0077] In an exemplary embodiment of the present disclosure, the positive active material may further include a binder and a conductive material. In this case, the contents of the binder and the conductive material may be about 1 wt % to 5 wt % respectively based on the total weight of the positive active material layer.

[0078] The binder may be configured to adhere the positive electrode active material particles to each other or to adhere the positive electrode active material particles to each other, and also to adhere the positive electrode active material to the positive electrode substrate or to adhere the positive electrode active material to the positive electrode substrate. Representative examples of binders include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene butadiene rubber, acrylated styrene butadiene rubber, epoxy resin, nylon, etc., but are not limited thereto.

[0079] The conductive material is used to impart conductivity to the electrode, and may be any material as long as the conductive material does not cause chemical changes in the constructed battery.

[0080] The negative electrode 12 may be Figure 1 The negative electrode 12 may include a substrate and an active material layer formed on the substrate and including a lower layer, an intermediate layer and an upper layer. The active material layer may include a pattern layer made of or including a silicon-based active material and a lower layer, a filling layer and an upper layer made of or including a carbon-based active material.

[0081] The negative electrode 12 includes an electrode active region DB1 and an electrode uncoated region DB2, and the electrode active region DB1 includes a substrate formed of or including a thin plate metal foil and a negative electrode active material layer (or intermediate layer) made of or including a negative electrode active material on the substrate. The electrode uncoated region DB2 is a region in which the negative electrode active material layer is not formed and the substrate is exposed, and may be a portion extending from the substrate of the electrode active region DB1.

[0082] The electrode uncoated area DB2 of the negative electrode 12 may be located at one side end of the negative electrode 12 along the length direction of the negative electrode 12. In this case, the electrode uncoated area DA2 of the positive electrode 11 and the electrode uncoated area DB2 of the negative electrode 12 may be located at opposite sides of the electrode active areas DA1 and DB1.

[0083] The electrode uncoated regions of the positive electrode 11 and the negative electrode 12 may have a shape protruding from the substrate at regular intervals along the winding direction, or may be located at the front end or the rear end of the wound electrode assembly 10 .

[0084] Meanwhile, the electrode assembly 10 may be accommodated in the case 27 together with an electrolyte, and the electrolyte may include a nonaqueous organic solvent and a lithium salt.

[0085] The nonaqueous organic solvent may serve as a medium through which ions participating in an electrochemical reaction of a battery may move.

[0086] The lithium salt is a substance dissolved in an organic solvent and used as a supply source of lithium ions in the battery, enabling the basic operation of the rechargeable battery 1000 and promoting the movement of lithium ions between the positive electrode and the negative electrode. Representative examples of the lithium salt include selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiN(SO2C2F5)2, Li(CF3SO2)2N, LiN(SO3C2F5)2, LiC4F9SO3, LiClO4, LiAlO2, LiAlCl4, LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2) (wherein x and y are natural numbers, for example, integers from 1 to 20), one or two or more of LiCl, LiI, and LiB(C2O4)2 (lithium bis(oxalato)borate (LiBOB)) as supporting electrolyte salts. In various examples, the concentration of the lithium salt may be in the range of about 0.1 M to 2.0 M. When the concentration of the lithium salt is included in the above range, improved electrolyte performance may be achieved because the electrolyte has appropriate conductivity and viscosity, and lithium ions may move more efficiently.

[0087] The housing 27 may be made of or include a metal such as aluminum and may have a substantially rectangular parallelepiped shape. One side of the housing 27 may be open, and the cover plate 31 may be mounted on the open side of the housing 27.

[0088] The cap assembly 30 includes a cap plate 31 coupled to the shell 27 to block an opening of the shell 27 , a positive terminal 21 electrically connected to the positive electrode 11 , and a negative terminal 22 electrically connected to the negative electrode 12 , wherein the positive terminal 21 and the negative terminal 22 protrude outside the cap plate 31 .

[0089] The cover plate 31 is formed in the form of a long plate extending in one direction, and is coupled to the opening of the housing 27 .

[0090] The cap plate 31 may have an injection hole 32 penetrating the inside. The injection hole 32 is used to inject electrolyte and is installed with a sealing plug 38. In addition, a vent plate 39 having a notch 39a is installed in the vent hole 34 so that the cap plate 31 can be opened at a set pressure.

[0091] The positive terminal 21 and the negative terminal 22 are installed to protrude upward from the cap plate 31 . The positive terminal 21 is electrically connected to the positive electrode 11 through the current collecting tab 41 , and the negative terminal 22 is electrically connected to the negative electrode 12 through the current collecting tab 42 .

[0092] The terminal connection member 25 is installed between the positive terminal 21 and the current collecting tab 41 to electrically connect the positive terminal 21 and the current collecting tab 41. The terminal connection member 25 is inserted into a hole formed in the positive terminal 21 so that its upper end is fixed to the positive terminal 21 by, for example, welding or other bonding methods, and its lower end is fixed to the current collecting tab 41 by, for example, welding or other bonding methods.

[0093] Between the terminal connection member 25 and the cap plate 31, a sealing gasket 59 may be inserted into a hole through which the terminal connection member 25 extends, and a lower insulating member 43 into which a lower portion of the terminal connection member 25 is inserted is installed under the cap plate 31. A connecting plate 58 is installed between the positive terminal 21 and the cap plate 31 to electrically connect the positive terminal 21 to the cap plate 31. The terminal connection member 25 is inserted into the connecting plate 58. Thus, the cap plate 31 and the case 27 are charged by the positive electrode 11.

[0094] The terminal connection member 26 is installed between the negative terminal 22 and the current collecting tab 42 to electrically connect the negative terminal 22 to the current collecting tab 42. The terminal connection member 26 is inserted into a hole formed in the negative terminal 22 so that its upper end is fixed to the negative terminal 22 by, for example, welding or other bonding methods, and its lower end is fixed to the current collecting tab 42 by, for example, welding or other methods.

[0095] Between the negative terminal 22 and the cap plate 31, a sealing gasket 59 is inserted and installed into a hole through which the terminal connection member 26 passes, and an upper insulating member 54 is installed to insulate the negative terminal 22 from the cap plate 31. The terminal connection member 26 may be installed by being inserted into the hole of the upper insulating member 54, and the upper insulating member 54 may be formed to surround one end of the negative terminal 22.

[0096] In addition, under the cap plate 31 , a lower insulating member 45 may be installed to insulate the negative terminal 22 and the current collecting tab 42 from the cap plate 31 .

[0097] A short-circuit hole 37 is formed in the cap plate 31, and a short-circuit member 56 is installed in the short-circuit hole 37. The short-circuit member 56 includes a bent portion convexly bent downward in an arc shape and an edge portion formed at an outer side of the bent portion and fixed to the cap plate 31. The upper insulating member 54 may have a cutout overlapping the short-circuit hole 37, and the short-circuit member 56 overlaps the negative terminal 22 exposed through the cutout.

[0098] The short-circuit member 56 is electrically connected to the cap plate 31 and deforms when the internal pressure of the rechargeable battery 1000 increases, causing a short circuit between the positive electrode 11 and the negative electrode 12. In other words, when gas is generated due to an abnormal reaction inside the rechargeable battery 1000, the internal pressure of the rechargeable battery 1000 increases. When the internal pressure of the rechargeable battery 1000 becomes higher than a preset pressure, the bent portion may be deformed to bulge upward, at which time the negative terminal 22 and the short-circuit member 56 may contact each other, causing a short circuit.

[0099] To facilitate short circuit between the negative terminal 22 and the short circuit member 56 , the negative terminal 22 may further include at least one protrusion (not shown) protruding toward the short circuit member 56 , and the protrusion may be spaced apart from the short circuit member 56 .

[0100] While the disclosure has been described in conjunction with what are presently considered to be example embodiments, it is to be understood that the disclosure is not limited to the disclosed example embodiments, but on the contrary, is intended to cover various modifications and equivalent constructions or arrangements included within the spirit and scope of the appended claims.

[0101] <Description of symbols> 7: Pattern layer 8: Filling layer 10: Electrode assembly 11: Positive electrode 12, 700: Negative electrode 13: Separator 21: Positive terminal 22: Negative terminal 27: Shell 30: Cover assembly 41, 42: current collecting lug 71: lower layer 72: middle layer 73: upper layer 500: slot die 510, 520, 530: discharge port 710: substrate 720: negative electrode active material layer 1000: Rechargeable battery P1, P2, P3: Spacers S1, S2, S3: Open

Claims

1. An electrode for a rechargeable battery, the electrode for a rechargeable battery comprising: substrate; a lower layer formed on the substrate; a pattern layer formed on the lower layer, the pattern layer having a plurality of parts; a filling layer formed on the lower layer and located between the plurality of portions of the pattern layer; as well as An upper layer is formed on the pattern layer and the filling layer.

2. The electrode for a rechargeable battery according to claim 1, wherein The expansion characteristics of the pattern layer are greater than the expansion characteristics of the filling layer, the lower layer, and the upper layer.

3. The electrode for a rechargeable battery according to claim 2, wherein At least one of the lower layer, the filling layer and the upper layer includes a carbon-based active material, and The pattern layer includes silicon-based active materials.

4. The electrode for a rechargeable battery according to claim 2, wherein The filling layer and the upper layer include the same active material.

5. The electrode for a rechargeable battery according to claim 1, wherein The viscosity of the pattern layer is greater than that of the filling layer and the upper layer.

6. The electrode for a rechargeable battery according to claim 5, wherein The viscosity of the upper layer and the filling layer is 3000±1500 mPas, and The viscosity of the pattern layer is 9500±4500 mPas.

7. The electrode for a rechargeable battery according to claim 1, wherein The portions of the pattern layer include a plurality of columns having a length in one direction.

8. The electrode for a rechargeable battery according to claim 1, wherein The plurality of portions of the pattern layer are arranged in a matrix.

9. An electrode assembly, comprising: a negative electrode comprising the electrode for a rechargeable battery according to claim 1; a positive electrode, stacked with the negative electrode; as well as A separator is between the negative electrode and the positive electrode.

10. An active material coating device, comprising: a slot die having a first opening, a second opening, and a third opening; first spacers, respectively located on both sides of the first opening to form a first discharge port; second spacers positioned at regular intervals in the second opening to form a plurality of second discharge ports; as well as a third spacer positioned in the third opening to form a third discharge port, The third spacer includes a first portion and a second portion, wherein the first portion is located at a position corresponding to one of the plurality of second discharge ports of the second opening, and the second portion is located at a portion corresponding to one of the first spacers of the first spacers of the first opening.

11. The active material coating device according to claim 10, wherein: The third discharge port includes a first small discharge port and a second small discharge port, the first small discharge port being located at a position corresponding to the second spacer of the second opening, the second small discharge port being located at a position corresponding to the first discharge port, and The first small exhaust port and the second small exhaust port are connected to form the third exhaust port.

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