Rechargeable lithium battery and method of manufacturing same

Abstract

A rechargeable lithium battery and a method of manufacturing the same are disclosed. A rechargeable lithium battery includes stacked unit cells and a separator between the unit cells. At least one of the unit cells includes a composite current collector having a top surface and a bottom surface opposed to each other, a first active material layer on the top surface of the composite current collector, and a second active material layer on the bottom surface of the composite current collector. And the composite current collectors of the adjacent unit cells are in contact with each other.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2024-0106570, filed on August 9, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a composite substrate for a rechargeable lithium battery and a rechargeable lithium battery including the composite substrate. Background Technology

[0003] With the increasing prevalence of battery-powered electronic devices (such as mobile phones, laptops, and electric vehicles), the demand for rechargeable batteries with high energy density and high capacity is growing. Therefore, improving the performance of rechargeable lithium-ion batteries may be advantageous.

[0004] A rechargeable lithium battery typically includes a positive electrode, a negative electrode, and an electrolyte. The positive and negative electrodes contain active materials in which lithium ions can be inserted and extracted, and the rechargeable lithium battery generates electrical energy from the oxidation and reduction reactions that occur during the insertion and extraction of lithium ions. Summary of the Invention

[0005] Example embodiments of this disclosure include rechargeable lithium batteries using composite current collectors.

[0006] According to an example embodiment of this disclosure, a rechargeable lithium battery may include a plurality of stacked cell units and a separator between the plurality of cell units. Each or at least one of the plurality of cell units may include a composite current collector having a top surface and a bottom surface opposite each other, a first active material layer on the top surface of the composite current collector, and a second active material layer on the bottom surface of the composite current collector. The composite current collectors of adjacent cell units may be in contact with each other.

[0007] According to an example embodiment of this disclosure, a rechargeable lithium battery may include a plurality of stacked cell units, a separator between the plurality of cell units, and an electrolyte in contact with the separator. Each or at least one of the plurality of cell units may include a composite current collector, a first active material layer on the top surface of the composite current collector, and a second active material layer on the bottom surface of the composite current collector. The electrolyte may also be in contact with the first and second active material layers. The composite current collectors of adjacent cell units may be in contact with each other.

[0008] According to an example embodiment of this disclosure, a method of manufacturing a rechargeable lithium battery may include the following steps: stacking a plurality of cell units, wherein each or at least one of the plurality of cell units includes a composite current collector having a top surface and a bottom surface opposite to each other; sealing one, two, and three of a first, second, third, and fourth surface of each of the plurality of cell units, wherein the first and second surfaces are opposite to each other, the third and fourth surfaces are opposite to each other, and the first and second surfaces intersect with the third and fourth surfaces; introducing an electrolyte through the fourth surface; and sealing the fourth surface. Each or at least one of the plurality of cell units may further include a first active material layer on the top surface of the composite current collector and a second active material layer on the bottom surface of the composite current collector. The composite current collectors of adjacent cell units may be in contact with each other. Attached Figure Description

[0009] Figure 1 A simplified conceptual diagram of a rechargeable lithium battery according to an example embodiment of the present disclosure is shown.

[0010] Figures 2 to 5 A simplified diagram of a rechargeable lithium battery according to an example embodiment of the present disclosure is shown.

[0011] Figure 6 A perspective view of a rechargeable lithium battery according to an example embodiment of the present disclosure is shown.

[0012] Figure 7 It shows along Figure 6 A sectional view taken by line A-A'.

[0013] Figure 8 It shows along Figure 6 The sectional view taken by line B-B'.

[0014] Figure 9 A perspective view of a composite current collector according to an example embodiment of the present disclosure is shown.

[0015] Figure 10 It shows along Figure 9 A sectional view taken by line A-A'.

[0016] Figure 11 A perspective view of a cell according to an example embodiment of the present disclosure is shown.

[0017] Figure 12 It shows along Figure 11 A sectional view taken by line A-A'.

[0018] Figure 13 A perspective view of multiple stacked cell cells according to an exemplary embodiment of the present disclosure is shown.

[0019] Figure 14 It shows along Figure 13 A sectional view taken by line A-A'.

[0020] Figure 15 A perspective view of multiple stacked cell cells according to an exemplary embodiment of the present disclosure is shown.

[0021] Figure 16 It shows along Figure 15 A sectional view taken by line A-A'.

[0022] Figure 17 It shows along Figure 15 The sectional view taken by line B-B'.

[0023] Figure 18 A perspective view of multiple stacked cell cells according to an exemplary embodiment of the present disclosure is shown.

[0024] Figure 19 It shows along Figure 18 A sectional view taken by line A-A'.

[0025] Figure 20 It shows along Figure 18 The sectional view taken by line B-B'.

[0026] Figure 21 A perspective view of multiple stacked cell cells according to an exemplary embodiment of the present disclosure is shown.

[0027] Figure 22 It shows along Figure 21 The sectional view taken by line B-B'.

[0028] Figure 23 This is a flowchart illustrating a method for manufacturing a rechargeable lithium battery according to an example embodiment. Detailed Implementation

[0029] To fully understand the structure and effects of this disclosure, some exemplary embodiments of the disclosure have been described with reference to the accompanying drawings. However, it should be noted that this disclosure is not limited to the following exemplary embodiments and can be implemented in various forms. Rather, the exemplary embodiments are provided merely to disclose the disclosure and to enable those skilled in the art to fully understand its scope.

[0030] In this specification, it is understood that when an element is referred to as being "on" another element, the element may be "directly on" the other element, or an intervening element may be present between them. In the accompanying drawings, the thickness of some components may be exaggerated for the purpose of effectively interpreting the technical content. Throughout the specification, the same reference numerals denote the same elements.

[0031] Unless otherwise specifically stated in this specification, singular expressions may include plural expressions. Furthermore, unless otherwise specifically stated, the phrase "A or B" may mean "A but not B," "B but not A," and "A and B." The term "including / comprises" and / or variations thereof as used in this disclosure do not exclude the presence or addition of one or more other components.

[0032] As used herein, the term "combination thereof" may refer to mixtures, stacks, complexes, copolymers, alloys, blends, or reaction products.

[0033] Unless otherwise specifically defined in this specification, particle size may be the average particle size. Additionally, particle size refers to the average particle size (D) that constitutes approximately 50% of the cumulative volume in the particle size distribution. 50 Average particle size (D) 50 The particle size can be measured using methods widely known to those skilled in the art (e.g., by a particle size analyzer, transmission electron microscopy (TEM) images, or scanning electron microscopy (SEM) images). Alternatively, data analysis can be performed using a dynamic light scattering measurement device to count the number of particles in each particle size range, from which the average particle size (D) can be calculated. 50 The average particle size (D) can be measured using laser scattering, unlike other methods. 50 In the laser scattering method, target particles are dispersed in a dispersion solvent and introduced into a laser scattering particle measuring device (e.g., the MT 3000, commercially available from Microtrac). They are then irradiated with 28 kHz ultrasound at a power of 60 W. The average particle size (D) is then calculated using a 50% standard of particle size distribution within the measuring device. 50 ).

[0034] When the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, it is intended that the relevant numerical value includes a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​within that range, such as increments of 0.1%.

[0035] Figure 1 This is a simplified conceptual diagram illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure. (Refer to...) Figure 1 A rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte ELL.

[0036] The positive electrode 10 and the negative electrode 20 can be spaced apart from each other by a diaphragm 30. The diaphragm 30 can be located between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20 and the diaphragm 30 can be in contact with the electrolyte ELL. The positive electrode 10, the negative electrode 20 and the diaphragm 30 can be immersed in the electrolyte ELL.

[0037] The electrolyte ELL can be or includes a medium through which lithium ions are transferred between the positive electrode 10 and the negative electrode 20. In the electrolyte ELL, lithium ions can move toward one of the positive electrode 10 and the negative electrode 20 through the membrane 30.

[0038] Positive electrode 10 The positive electrode 10 for a rechargeable lithium battery may include a current collector COL1 and a positive electrode active material layer AML1 on the current collector COL1. The positive electrode active material layer AML1 may include a positive electrode active material and may further include a binder and / or a conductive material.

[0039] For example, the positive electrode 10 may also include additives that can be configured as a sacrificial positive electrode.

[0040] The amount of positive electrode active material relative to 100 wt% of the positive electrode active material layer AML1 can range from about 90 wt% to about 99 wt%. The amount of each of the binder and conductive material relative to 100 wt% of the positive electrode active material layer AML1 can range from about 0.5 wt% to about 5 wt%.

[0041] The binder can be configured to improve the adhesion between the positive electrode active material particles and the adhesion between the positive electrode active material and the current collector COL1. The binder may include, for example, at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin and nylon, but this disclosure is not limited thereto.

[0042] Conductive materials can provide electrode conductivity and can include any suitable conductive material that does not cause chemical changes in the battery. Conductive materials can include, for example: carbon-based materials, such as or including at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metal powders or metal fibers, comprising one or more of copper, nickel, aluminum, and silver; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0043] Aluminum (Al) may be included as the current collector COL1, but this disclosure is not limited thereto.

[0044] Positive electrode active material The positive electrode active material in the positive electrode active material layer AML1 may include compounds that can reversibly insert and deintercalate lithium (e.g., lithiation intercalation compounds). For example, the positive electrode active material may include at least one of a composite oxide containing lithium and a metal (such as or including at least one of cobalt, manganese, nickel, and combinations thereof).

[0045] The composite oxide may include lithium transition metal composite oxides, such as lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free lithium nickel manganese oxides, and combinations thereof, at least one of these.

[0046] For example, the positive electrode active material may include a compound represented by one of the following chemical formulas: Li a A 1- b X b O 2-c D c (Where, 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (Where, 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni b Co c L 1 d G e O2 (where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, and 0≤e≤0.1); Li a NiG b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a CoG bO2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-b G b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn2G b O4 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (where 0.90 ≤ a ≤ 1.8 and 0 ≤ g ≤ 0.5); Li (3-f) Fe2(PO4)3 (where 0≤f≤2); Li a FePO4 (where 0.90≤a≤1.8).

[0047] In the above chemical formulas, A is or includes at least one of Ni, Co, Mn, and combinations thereof; X is or includes at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, and combinations thereof; D is or includes at least one of O, F, S, P, and combinations thereof; G is or includes at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, and combinations thereof; and L 1 It is or includes at least one of Mn, Al and combinations thereof.

[0048] For example, the positive electrode active material may be or include a high-nickel positive electrode active material, wherein the nickel content of the high-nickel positive electrode active material is equal to or greater than about 80 mol%, equal to or greater than about 85 mol%, equal to or greater than about 90 mol%, equal to or greater than about 91 mol%, or equal to or greater than about 94 mol% and equal to or less than about 99 mol%, relative to 100 mol% of lithium-free metal in the lithium transition metal complex oxide. High-nickel positive electrode active materials can achieve high capacity and are therefore suitable for high-capacity and high-density rechargeable lithium batteries.

[0049] negative electrode 20 The negative electrode 20 for a rechargeable lithium battery may include a current collector COL2 and a negative electrode active material layer AML2 located on the current collector COL2. The negative electrode active material layer AML2 may include a negative electrode active material and may further include a binder and / or a conductive material.

[0050] For example, the negative electrode active material layer AML2 may include a negative electrode active material ranging from about 90 wt% to about 99.5 wt%, a binder ranging from about 0.5 wt% to about 5 wt%, and a conductive material ranging from about 0 wt% to about 5 wt%.

[0051] The binder can be configured to improve the adhesion between the negative electrode active material particles and the adhesion between the negative electrode active material and the current collector COL2. The binder may include at least one of non-aqueous binders, aqueous binders, dry binders, and combinations thereof.

[0052] Non-aqueous adhesives may include at least one of polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, and combinations thereof.

[0053] Waterborne adhesives may include at least one of the following: styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomers, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0054] When an aqueous binder is included as the negative electrode binder, a cellulose compound capable of providing adhesion may be further included. The cellulose compound may include one or more of carboxymethyl cellulose, hydroxypropyl methylcellulose, methylcellulose, and their alkali metal salts. The alkali metal may include at least one of Na, K, and Li.

[0055] Dry adhesives may include at least one of the following: fibrous polymeric materials, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and combinations thereof.

[0056] Conductive materials may be included to provide electrode conductivity, and may include any suitable conductive material that does not cause chemical changes in the battery. For example, conductive materials may include carbon-based materials, such as at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metal powders or metal fibers, including one or more of copper, nickel, aluminum, and silver; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0057] The current collector COL2 may include at least one of copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof.

[0058] Negative electrode active material The negative electrode active material in the negative electrode active material layer AML2 may include at least one of a material capable of reversibly inserting and extracting lithium ions, lithium metal, a lithium metal alloy, a material capable of doping and undoping lithium, and a transition metal oxide.

[0059] The material capable of reversibly inserting and extracting lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. For example, crystalline carbon may include graphite, such as natural graphite or artificial graphite that is unshaped, flaky, lamellar, spherical, or fibrous, and amorphous carbon may include at least one of soft carbon, hard carbon, mesophase pitch carbon, and calcined coke.

[0060] The lithium metal alloy may include an alloy of lithium and a metal (being or including at least one of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn).

[0061] The material capable of doping and undoping lithium may include at least one of a Si-based negative electrode active material and a Sn-based negative electrode active material. The Si-based negative electrode active material may include silicon, a silicon-carbon composite, SiO x (where 0 < x ≤ 2), a Si-Q alloy (where Q is or includes at least one of an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (other than Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, and a combination thereof), and a combination thereof. The Sn-based negative electrode active material may include at least one of Sn, SnO2, a Sn-based alloy, and a combination thereof.

[0062] The silicon-carbon composite may be or include a composite of silicon and amorphous carbon. According to an exemplary embodiment, the silicon-carbon composite may have a structure in which amorphous carbon is coated on the surface of silicon particles. For example, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are assembled and an amorphous carbon coating (shell) located on the surface of the secondary particles. Amorphous carbon may also be located between the primary silicon particles, and for example, the primary silicon particles may be coated with amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0063] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles, and may also include an amorphous carbon coating located on the surface of the core.

[0064] The Si-based negative electrode active material or the Sn-based negative electrode active material may be included in combination with the carbon-based negative electrode active material.

[0065] Separator 30 Depending on the type of rechargeable lithium battery, the separator 30 may be located between the positive electrode 10 and the negative electrode 20. The separator 30 may include one or more of polyethylene, polypropylene, and polyvinylidene fluoride, and may have multiple layers, such as a polyethylene / polypropylene bilayer separator, a polyethylene / polypropylene / polypropylene trilayer separator, and a polypropylene / polypropylene / polypropylene trilayer separator.

[0066] The diaphragm 30 may include a porous substrate and a coating on one or opposite surface of the porous substrate, comprising at least one of organic materials, inorganic materials and combinations thereof.

[0067] The porous substrate may be or include a polymer layer, which includes at least one of polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, and Teflon (polytetrafluoroethylene), or may be a copolymer or mixture of two or more of the above materials.

[0068] Organic materials may include polyvinylidene fluoride copolymers or (meth)acrylic acid copolymers.

[0069] Inorganic materials may include inorganic particles such as or including at least one of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof, but this disclosure is not limited thereto.

[0070] Organic and inorganic materials can be mixed in a coating, or they can exist as a stack of a coating that includes organic materials and another coating that includes inorganic materials.

[0071] Electrolyte ELL Electrolytes (ELLs) used in rechargeable lithium batteries may include non-aqueous organic solvents and lithium salts.

[0072] Non-aqueous organic solvents can be constructed as media for transporting ions that participate in the electrochemical reactions of a battery.

[0073] Non-aqueous organic solvents may include at least one of carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents, and combinations thereof.

[0074] Carbonate solvents may include at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), and butyl carbonate (BC).

[0075] Ester solvents may include at least one of methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonate lactone, valproic acid lactone, and caprolactone.

[0076] Ether solvents may include at least one of dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, and tetrahydrofuran. Ketone solvents may include cyclohexanone. Alcohol solvents may include at least one of ethanol and isopropanol, and aprotic solvents may include at least one of: nitriles, such as R-CN (wherein R is a hydrocarbon group having a C2 to C20 straight-chain, branched, or cyclic structure, and may include double bonds, aromatic rings, or ether bonds); amides, such as dimethylformamide; dioxolane, such as 1,3-dioxolane or 1,4-dioxolane; and sulfolane.

[0077] Non-aqueous organic solvents may be included alone or as a mixture of two or more substances.

[0078] Additionally, when carbonate solvents are included, cyclic carbonates and chain carbonates can be mixed, and cyclic carbonates and chain carbonates can be mixed in a volume ratio ranging from about 1:1 to about 1:9.

[0079] Lithium salts can be or include materials dissolved in non-aqueous organic solvents to be configured as a supply source of lithium ions in a battery, enabling the basic operation of a rechargeable lithium battery and facilitating the movement of lithium ions between the positive and negative electrodes. Lithium salts can include, for example, LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N (lithium bis(fluorosulfonyl)imide, LiFSI), LiC4F9SO3, LiN(C F 2x+1 SO2)(C y F 2y+2 At least one of the following: (SO2) (where x and y are integers from 1 to 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalate)phosphate (LiDFBOP), and lithium bis(oxalate)borate (LiBOB).

[0080] Rechargeable lithium batteries Based on their shape, rechargeable lithium batteries can be classified into cylindrical, prismatic, pouch-shaped, and coin-shaped types. Figures 2 to 5 A simplified diagram illustrating a rechargeable lithium battery according to an embodiment is shown, and Figure 2 A cylindrical battery is shown. Figure 3 A prismatic battery is shown, and Figure 4 and Figure 5 A pouch-type battery is shown. (See reference) Figures 2 to 4 The rechargeable lithium battery 100 may include an electrode assembly 40 in which a separator 30 is disposed between a positive electrode 10 and a negative electrode 20, and may also include a housing 50 therein housing the electrode assembly 40. The positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in an electrolyte (not shown). Figure 2 As shown, the rechargeable lithium battery 100 may include a sealing member 60 of the sealed housing 50. Additionally, as... Figure 3 As shown, the rechargeable lithium battery 100 may include a positive electrode lead connector 11, a positive electrode terminal 12, a negative electrode lead connector 21, and a negative electrode terminal 22. Figure 4 and Figure 5 As shown, the rechargeable lithium battery 100 may include Figure 5 The electrode connector 70 shown, or Figure 4 The positive electrode terminal 71 and negative electrode terminal 72 shown form an electrical path for guiding the current generated in the electrode assembly 40 to the outside.

[0081] Figure 6 A perspective view of a rechargeable lithium battery according to an example embodiment of the present disclosure is shown. Figure 7 It shows along Figure 6 A sectional view taken by line A-A'. Figure 8 It shows along Figure 6 The cross-sectional view taken along line B-B'. For the sake of brevity, references are omitted. Figures 1 to 5 The discussion of rechargeable lithium batteries is redundant.

[0082] Reference Figures 6 to 8 A rechargeable lithium battery according to some example embodiments of this disclosure may include a plurality of stacked cell cells CEL (e.g., CEL1, CEL2, CEL3), and a separator 30 and an electrolyte ELL disposed between the plurality of cell cells CEL1, CEL2, CEL3. The separator 30 may correspond to the above-mentioned references. Figure 1 The diaphragm 30 is under discussion.

[0083] Multiple battery cells CEL1, CEL2, and CEL3 can be stacked along a third direction D3. These multiple battery cells CEL1, CEL2, and CEL3 may include, for example, a first battery cell CEL1, a second battery cell CEL2 mounted on the first battery cell CEL1, and a third battery cell CEL3 mounted on the second battery cell CEL2. The first battery cell CEL1, the second battery cell CEL2, and the third battery cell CEL3 can be electrically connected to each other.

[0084] Reference Figure 6 Only three cell units CEL1, CEL2, and CEL3 are shown, but this disclosure is not limited thereto, and for example, more than three cell units can be stacked together.

[0085] Each of the multiple cell units CEL1, CEL2, CEL3 may include a composite current collector CPS having a top surface and a bottom surface opposite each other, a first active material layer AL1 on the top surface of the composite current collector CPS, and a second active material layer AL2 on the bottom surface of the composite current collector CPS.

[0086] The first active substance layer AL1 may be or includes the above references. Figure 1 The discussion focuses on one of the positive electrode active material layer AML1 and the negative electrode active material layer AML2. The second active material layer AML2 may be or include the above-mentioned references. Figure 1 The other of the positive electrode active material layer AML1 and the negative electrode active material layer AML2 discussed. In the exemplary embodiments of this disclosure, the first active material layer AML1 may be the positive electrode active material layer AML1, and the second active material layer AML2 may be the negative electrode active material layer AML2.

[0087] The composite current collector (CPS) may include a support layer SPL, a first metal layer ME1 on the top surface of the support layer SPL, and a second metal layer ME2 on the bottom surface of the support layer SPL. Each or at least one of the first metal layer ME1 and the second metal layer ME2 may have a thickness, for example, in the range of about 200 nm to about 5 μm. A first active material layer AL1 may be located on the first metal layer ME1, and a second active material layer AL2 may be located on the second metal layer ME2. Each of the first metal layer ME1 and the second metal layer ME2 of the composite current collector CPS may correspond to the above references. Figure 1 One of the current collectors COL1 and COL2 discussed. Each or at least one of the first metal layer ME1 and the second metal layer ME2 may include at least one of aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, iron, iron alloy, silver, and silver alloy.

[0088] The support layer SPL can be or includes, for example, a porous membrane. The porosity of the support layer SPL can range, for example, from about 30% to about 70%, from about 35% to about 55%, from about 42% to about 64%, from about 31% to about 62%, or from about 48% to about 65%. The thickness of the support layer SPL can range, for example, from about 3 μm to about 10 μm. When the porosity and / or thickness of the support layer SPL falls within the above ranges, the rechargeable lithium battery can exhibit desired or improved mechanical stability and high integration. The support layer SPL can include, for example, one or more multilayer films such as polyethylene membranes, polypropylene membranes, polyvinylidene chloride membranes, and combinations thereof.

[0089] The composite current collectors (CPS) of adjacent cell units CEL1, CEL2, and CEL3 can be in contact with each other. For example, the support layers (SPL) of adjacent cell units CEL1, CEL2, and CEL3 can be in contact with each other and can be combined into a single integral unit. The combined support layer (SPL) can surround the first metal layer ME1, the first active material layer AL1, the separator 30, the second metal layer ME2, and the second active material layer AL2.

[0090] For example, the support layer SPL of the first cell CEL1 and the support layer SPL of the second cell CEL2 can be combined into a single integral component. The combined support layer SPL can surround the first metal layer ME1 and the first active material layer AL1 of the first cell CEL1, the second metal layer ME2 and the second active material layer AL2 of the second cell CEL2, and the separator 30.

[0091] For example, the support layer SPL of the second cell CEL2 and the support layer SPL of the third cell CEL3 can be combined into a single integral component. The combined support layer SPL can surround the first metal layer ME1 and the first active material layer AL1 of the second cell CEL2, the second metal layer ME2 and the second active material layer AL2 of the third cell CEL3, and the separator 30.

[0092] The support layer (SPL) according to some example embodiments of this disclosure can perform multiple functions of supporting and encapsulating the composite substrate. Therefore, rechargeable lithium batteries can exhibit desired or improved space utilization.

[0093] The electrolyte ELL can be located within the combined support layer SPL. For example, the support layer SPL of the first cell CEL1 and the support layer SPL of the second cell CEL2 can be combined into a single integral unit. The electrolyte ELL can fill the interior of the combined support layer SPL. For example, the support layer SPL of the second cell CEL2 and the support layer SPL of the third cell CEL3 can be combined into a single integral unit. The electrolyte ELL can fill the interior of the combined support layer SPL.

[0094] The electrolyte ELL can contact the first metal layer ME1, the first active material layer AL1, the second metal layer ME2, the second active material layer AL2, and the separator 30. The first metal layer ME1, the first active material layer AL1, the second metal layer ME2, the second active material layer AL2, and the separator 30 can be immersed in the electrolyte ELL. The electrolyte ELL can correspond to a reference. Figure 1 The electrolyte ELL is under discussion.

[0095] Figures 6 to 8 The first cell CEL1, the second cell CEL2, the third cell CEL3, the electrolyte ELL, and the separator 30 can constitute the above reference. Figures 3 to 5 Electrode assembly 40 is discussed.

[0096] Figures 9 to 22 This is a diagram illustrating a method for manufacturing a rechargeable lithium battery according to an exemplary embodiment of the present disclosure. Figure 9 This is a perspective view showing a composite current collector according to an exemplary embodiment of the present disclosure. Figure 10 It is along Figure 9 A sectional view taken by line A-A'. Figure 11 This is a perspective view showing a cell according to an example embodiment of the present disclosure. Figure 12 It shows along Figure 11 A sectional view taken by line A-A'. Figure 13 This is a perspective view showing a plurality of stacked cell cells according to an exemplary embodiment of the present disclosure. Figure 14 It shows along Figure 13 A sectional view taken by line A-A'. Figure 15 This is a perspective view showing a plurality of stacked cell cells according to an exemplary embodiment of the present disclosure. Figure 16 It shows along Figure 15 A sectional view taken by line A-A'. Figure 17 It shows along Figure 15 The sectional view taken by line B-B'. Figure 18 This is a perspective view showing a plurality of stacked cell cells according to an exemplary embodiment of the present disclosure. Figure 19 It shows along Figure 18 A sectional view taken by line A-A'. Figure 20 It shows along Figure 18 The sectional view taken by line B-B'. Figure 21 This is a perspective view showing a plurality of stacked cell cells according to an exemplary embodiment of the present disclosure. Figure 22 It shows along Figure 21 The cross-sectional view taken along line B-B'. For the sake of brevity, references are omitted. Figures 1 to 6 The discussion of rechargeable lithium batteries is redundant.

[0097] Reference Figure 9 and Figure 10 The composite current collector (CPS) may include a support layer SPL, a first metal layer ME1 on the top surface of the support layer SPL, and a second metal layer ME2 on the bottom surface of the support layer SPL. The support layer SPL may be, for example, a porous membrane. The porosity of the support layer SPL may be in the range of, for example, about 30% to about 70%, about 35% to about 55%, about 42% to about 64%, about 31% to about 62%, or about 48% to about 65%. The thickness of the support layer SPL may be in the range of, for example, about 3 μm to about 10 μm. Each or at least one of the first metal layer ME1 and the second metal layer ME2 may have a thickness in the range of, for example, about 200 nm to about 5 μm. Each or at least one of the first metal layer ME1 and the second metal layer ME2 may correspond to the above references. Figure 1 One of the current collectors COL1 and COL2 is being discussed.

[0098] Reference Figure 11 and Figure 12 A first active material layer AL1 can be coated onto the first metal layer ME1. A second active material layer AL2 can be coated onto the second metal layer ME2. This coating process can form the first cell CEL1.

[0099] The first active substance layer AL1 may be or includes the above references. Figure 1 The discussion focuses on one of the positive electrode active material layer AML1 and the negative electrode active material layer AML2. The second active material layer AML2 may be or include the above-mentioned references. Figure 1 The other of the positive electrode active material layer AML1 and the negative electrode active material layer AML2 discussed. In the exemplary embodiments of this disclosure, the first active material layer AML1 may be the positive electrode active material layer AML1, and the second active material layer AML2 may be the negative electrode active material layer AML2.

[0100] Reference Figure 13 and Figure 14 Multiple cell units CEL1, CEL2, and CEL3 can be stacked along a third direction D3. These multiple cell units CEL1, CEL2, and CEL3 may include, for example, a first cell CEL1, a second cell CEL2 mounted on the first cell CEL1, and a third cell CEL3 mounted on the second cell CEL2. The second cell CEL2 and the third cell CEL3 can be stacked along a third direction D3. Figures 9 to 12 The first cell CEL1 discussed is formed using the same method.

[0101] The separator 30 can be placed between multiple cell units CEL1, CEL2, and CEL3. The separator 30 can correspond to the above reference. Figure 1 The diaphragm 30 is under discussion.

[0102] Reference Figure 15 and Figure 16 This device can seal the first surface 1a, the second surface 2a, the third surface 3a, and the fourth surface 4a of each of multiple cell units CEL1, CEL2, and CEL3. The first surface 1a and the second surface 2a can be opposite each other, and the third surface 3a and the fourth surface 4a can also be opposite each other. The first surface 1a and the second surface 2a can intersect with the third surface 3a and the fourth surface 4a.

[0103] Sealing processes, such as hot pressing, can combine the support layers (SPLs) of multiple cell units CEL1, CEL2, and CEL3. Therefore, the support layers (SPLs) of multiple cell units CEL1, CEL2, and CEL3 can be connected and / or in contact with each other. For example, during the sealing process, the support layers (SPLs) of multiple cell units CEL1, CEL2, and CEL3 can be combined into a single integral component.

[0104] Reference Figure 17 and Figure 18 The first metal layer ME1, the first active material layer AL1, the second metal layer ME2, and the second active material layer AL2 of each of the multiple cell units CEL1, CEL2, and CEL3 can be exposed through the unsealed fourth surface 4a.

[0105] Reference Figure 19 and Figure 20 Electrolyte ELL can be introduced into multiple cell units CEL1, CEL2, and CEL3 through the unsealed fourth surface 4a. Electrolyte ELL can correspond to a reference... Figure 1 The electrolyte ELL is under discussion.

[0106] Reference Figure 21 and Figure 22 The fourth surface 4a of multiple cell units CEL1, CEL2, and CEL3 can be sealed. Sealing processes such as hot pressing can combine the support layer SPL with each other on the side of the fourth surface 4a of multiple cell units CEL1, CEL2, and CEL3.

[0107] The sealing process can complete all surfaces (e.g., first surface 1a, second surface 2a, third surface 3a, and fourth surface 4a) of multiple cell units CEL1, CEL2, and CEL3. During the sealing process, the electrolyte ELL can be sealed inside the closed support layer SPL. The sealing process allows the electrolyte ELL to fill the interior of the combined support layer SPL. The first metal layer ME1, the first active material layer AL1, the second metal layer ME2, the second active material layer AL2, and the separator 30 can be immersed in the electrolyte ELL.

[0108] Figure 23 This is a flowchart illustrating a method for manufacturing a rechargeable lithium-ion battery according to an example embodiment. In the example, method 2300 begins with operation 2310, which includes stacking a plurality of cell units. For example, each or at least one of the plurality of cell units includes a composite current collector. For example, the composite current collector includes a support layer, a first metal layer on a top surface of the support layer, and a second metal layer on a bottom surface of the support layer. In another example, the support layer includes one or more of a polyethylene film, a polypropylene film, a polyvinylidene chloride film, and multilayer films thereof. In yet another example, the support layers of adjacent cell units are combined into a single integral piece. For example, the porosity of the support layer is in the range of about 30% to about 70%. In the example, the thickness of at least one of the first and second metal layers is in the range of about 200 nm to about 5 μm, and the thickness of the support layer is in the range of about 3 μm to about 10 μm.

[0109] Operation 2320 includes sealing one of the first, second, third, and fourth surfaces of each or at least one of the plurality of cell units. For example, the first and second surfaces are opposite to each other. In another example, the third and fourth surfaces are opposite to each other. In yet another example, the first and second surfaces intersect with the third and fourth surfaces. Operation 2330 includes introducing electrolyte through the fourth surface. Operation 2340 includes sealing the fourth surface. For example, each or at least one of the plurality of cell units includes a composite current collector having a top surface and a bottom surface opposite to each other, a first active material layer on the top surface of the composite current collector, and a second active material layer on the bottom surface of the composite current collector. In another example, the composite current collectors of adjacent cell units are in contact with each other.

[0110] According to some example embodiments of this disclosure, each or at least one of a plurality of stacked cell units may include a composite current collector, the composite current collector including a support layer, a first active material layer on the top surface of the composite current collector, and a second active material layer on the bottom surface of the composite current collector. The support layers of adjacent cell units may contact each other and may be combined into a single integral unit. Therefore, electrolyte may fill the interior of the combined support layers. Thus, it is possible to provide a rechargeable lithium battery including this composite current collector. Additionally, this composite current collector may be included to provide a rechargeable lithium battery with desired or improved portability and space utilization.

[0111] Although some exemplary embodiments of the present disclosure have been discussed with reference to the accompanying drawings, it is understood that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure. It will be apparent to those skilled in the art that various substitutions, modifications, and alterations may be made therein without departing from the scope and spirit of the present disclosure.

Claims

1. A rechargeable lithium battery, said rechargeable lithium battery comprising: Multiple battery cells are stacked together; as well as A separator is placed between the multiple cell units. Each of the plurality of unit cells includes: The composite current collector has a top surface and a bottom surface that are opposite to each other; A first active material layer is located on the top surface of the composite current collector; and The second active material layer is located on the bottom surface of the composite current collector. In this configuration, the composite current collectors of adjacent unit cells in the plurality of unit cells are in contact with each other.

2. The rechargeable lithium battery according to claim 1, wherein, The composite current collector includes: The support layer has a top surface and a bottom surface that are opposite each other; A first metal layer is disposed on the top surface of the support layer; and The second metal layer is on the bottom surface of the support layer.

3. The rechargeable lithium battery according to claim 2, wherein, The support layers of the adjacent cell units are in contact with each other.

4. The rechargeable lithium battery according to claim 2, wherein, The support layer includes one or more of a multilayer film consisting of a polyethylene film, a polypropylene film, a polyvinylidene chloride film, and combinations thereof.

5. The rechargeable lithium battery according to claim 2, wherein, Each of the first metal layer and the second metal layer includes at least one of aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, iron, iron alloy, silver, and silver alloy.

6. The rechargeable lithium battery according to claim 2, wherein: The thickness of at least one of the first metal layer and the second metal layer is in the range of 200 nm to 5 μm, and The thickness of the support layer is in the range of 3 μm to 10 μm.

7. The rechargeable lithium battery according to claim 2, wherein, The porosity of the support layer is in the range of 30% to 70%.

8. The rechargeable lithium battery according to claim 1, wherein, At least one of the plurality of cell units further includes an electrolyte in contact with the first active material layer, the second active material layer and the diaphragm.

9. The rechargeable lithium battery according to claim 2, wherein, The support layers of the adjacent cell units are combined into a single integral component.

10. The rechargeable lithium battery according to claim 1, wherein, The multiple cell units are electrically connected to each other.

11. A rechargeable lithium battery, said rechargeable lithium battery comprising: Multiple stacked battery cells; A separator is placed between the plurality of cell units; as well as The electrolyte comes into contact with the diaphragm. At least one of the plurality of cell units includes: Composite current collector; A first active material layer is located on the top surface of the composite current collector; and The second active material layer is located on the bottom surface of the composite current collector. The electrolyte also comes into contact with the first active material layer and the second active material layer, and In this configuration, the composite current collectors of adjacent unit cells in the plurality of unit cells are in contact with each other.

12. The rechargeable lithium battery according to claim 11, wherein, The composite current collector includes: Support layer; A first metal layer is disposed on the top surface of the support layer; and The second metal layer is located on the bottom surface of the support layer. The support layers of adjacent cell units are combined into a single integral component, and The electrolyte fills the interior of the support layer of the assembly.

13. The rechargeable lithium battery according to claim 12, wherein, The support layer includes one or more of polyethylene film, polypropylene film, polyvinylidene chloride film, and their multilayer films.

14. The rechargeable lithium battery according to claim 12, wherein, The porosity of the support layer is in the range of 30% to 70%.

15. A method for manufacturing a rechargeable lithium battery, the method comprising the following steps: Multiple cell units are stacked, wherein each of the multiple cell units includes a composite current collector having a top surface and a bottom surface opposite each other; The first, second, third, and fourth surfaces of each of the plurality of cell units are sealed, wherein the first and second surfaces are opposite to each other, the third surface is opposite to the fourth surface, and the first and second surfaces intersect with the third and fourth surfaces. Electrolyte is introduced through the fourth surface; and Seal the fourth surface. Each of the plurality of unit cells further includes: A first active material layer is located on the top surface of the composite current collector; and The second active material layer is on the bottom surface of the composite current collector, and In this configuration, the composite current collectors of adjacent unit cells in the plurality of unit cells are in contact with each other.

16. The method according to claim 15, wherein, The composite current collector includes: Support layer; A first metal layer is disposed on the top surface of the support layer; and The second metal layer is on the bottom surface of the support layer.

17. The method according to claim 16, wherein, The support layer includes one or more of polyethylene film, polypropylene film, polyvinylidene chloride film, and their multilayer films.

18. The method according to claim 16, wherein, The support layers of the adjacent cell units are combined into a single integral component.

19. The method of claim 16, wherein, The porosity of the support layer is in the range of 30% to 70%.

20. The method of claim 16, wherein, The thickness of at least one of the first metal layer and the second metal layer is in the range of 200 nm to 5 μm, and The thickness of the support layer is in the range of 3 μm to 10 μm.

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