Pretreatment method of all-solid-state battery for recycling, pretreatment device thereof, and method for recovering positive electrode active material precursor and solid electrolyte using same

Abstract

The present invention relates to a pretreatment method of an all-solid-state battery. More specifically, the method comprises: immersing waste of an all-solid-state battery in oil; physically decomposing the waste in a state of being immersed in oil; and obtaining the decomposed product. The waste is at least one of a battery cell, a battery module, a battery pack, and a process scrap. The oil includes at least one selected from mineral oil, silicone oil, vegetable oil, and synthetic oil.

Description

Method for pretreatment of an all-solid-state battery for recycling, a pretreatment device thereof, and a method for recovering a cathode active material precursor and a solid electrolyte using the same

[0001] The present invention relates to a pretreatment method for recycling an all-solid-state battery, a pretreatment device thereof, and a method for recovering a positive electrode active material precursor and a solid electrolyte using the same.

[0002]

[0003] Recent industrial demands have led to the active development of batteries with high energy density and safety. For example, lithium-ion batteries are being used not only in information and communication devices, but also in the automotive sector. Safety is particularly important in the automotive sector, as it is directly related to life.

[0004] Recently, all-solid-state batteries have been proposed, replacing the electrolyte in lithium-ion batteries with a solid electrolyte. By eliminating the use of flammable organic dispersion media, all-solid-state batteries can significantly reduce the risk of fire or explosion in the event of a short circuit.

[0005] Because the key raw materials required for all-solid-state battery manufacturing must be obtained from natural resources, environmental destruction and pollution inevitably follow the raw material extraction process. Therefore, there is a pressing need to develop technologies to recover and recycle raw materials from spent batteries.

[0006] Typically, recycling raw materials such as precious metals involves crushing or pulverizing discarded batteries. All-solid-state batteries contain large amounts of metal, posing a risk of explosion or fire during crushing or pulverization. In particular, sulfide-based solid electrolytes, widely used as solid electrolytes in all-solid-state batteries, contain large amounts of sulfur, making them highly susceptible to moisture. Sulfur reacts with moisture to produce foul odors and toxic gases, making them difficult to handle in normal atmospheric conditions. Therefore, there is a growing demand for safer, more environmentally friendly recycling methods.

[0007]

[0008] The problem to be solved by the present invention is to provide a pretreatment method for an all-solid-state battery that is more environmentally friendly, economical, and secures stability.

[0009] Another problem to be solved by the present invention is to provide a method for preprocessing an all-solid-state battery that is easy to handle by omitting the disassembly process of a battery pack or module.

[0010]

[0011] A method for pretreatment of an all-solid-state battery according to the concept of the present invention may include immersing waste from an all-solid-state battery in oil; physically decomposing the waste while immersed in the oil; and obtaining a decomposed product. The waste may be at least one of a battery cell, a battery module, a battery pack, and process scrap. The oil may include at least one selected from mineral oil, silicone oil, vegetable oil, and synthetic oil.

[0012] A pretreatment device for an all-solid-state battery according to another concept of the present invention comprises a chamber filled with oil; and a decomposition means, and can pretreat all-solid-state battery waste according to the above-described pretreatment method for an all-solid-state battery.

[0013] A method for recovering a positive electrode active material precursor and a solid electrolyte according to another concept of the present invention may include providing a pretreated result according to the above-described pretreatment method for an all-solid-state battery; and recovering a positive electrode active material precursor and a solid electrolyte from the result.

[0014]

[0015] A pretreatment method according to one embodiment of the present invention can prevent explosion or fire by physically decomposing battery waste while immersed in oil. The present invention can provide a pretreatment method with improved moisture stability by suppressing side reactions between battery waste and moisture due to the use of oil. Furthermore, the present invention can reduce process costs because it uses relatively inexpensive oil. Consequently, one embodiment of the present invention can pretreat all-solid-state battery waste through a more environmentally friendly, economical, and safe method.

[0016] The present invention performs a pretreatment process on all-solid-state battery cells, modules, packs, or process scraps, thereby omitting a separate process for disassembling modules or packs, thereby enabling easier pretreatment of all-solid-state battery waste.

[0017]

[0018] FIG. 1A and FIG. 1B are cross-sectional views illustrating an all-solid-state battery according to embodiments of the present invention.

[0019] Figure 2 is a flowchart for explaining a pretreatment method for an all-solid-state battery according to one embodiment of the present invention.

[0020] Figure 3 is a schematic diagram illustrating a pretreatment device for an all-solid-state battery according to one embodiment of the present invention.

[0021]

[0022] To fully understand the structure and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and subject to various modifications. However, the description of these embodiments is provided solely to ensure a complete disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention.

[0023] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. Furthermore, in the drawings, the thicknesses of the components are exaggerated for the sake of clarity. Parts designated by the same reference numerals throughout the specification represent the same components.

[0024] Embodiments described herein will be described with reference to cross-sectional and / or plan views, which are ideal illustrations of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for the purpose of effectively explaining the technical contents. Accordingly, the regions illustrated in the drawings have a schematic nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, and third are used to describe various components in various embodiments of the present specification, these components should not be limited by such terms. These terms are used only to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments thereof.

[0025] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the words "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components.

[0026]

[0027] All-solid-state batteries

[0028] FIG. 1A and FIG. 1B are cross-sectional views illustrating an all-solid-state battery according to embodiments of the present invention.

[0029] Referring to FIG. 1A, the all-solid-state battery may include a cathode layer (100), a cathode layer (200) facing the cathode layer (100), and a solid electrolyte layer (300) for an all-solid-state battery disposed between the cathode layer (100) and the cathode layer (200). However, the present invention is not limited thereto, and the all-solid-state battery may further include an additional functional layer, such as an adhesion enhancing layer, disposed between the cathode layer (100) and the solid electrolyte layer (300) for an all-solid-state battery or between the cathode layer (200) and the solid electrolyte layer (300) for an all-solid-state battery.

[0030] The positive electrode layer (100) may include a positive electrode current collector (110) and a positive electrode active material layer (120) disposed on the positive electrode current collector (110). The positive electrode active material layer (120) may include a positive electrode active material, a solid electrolyte, a conductive material, and a binder.

[0031] The positive electrode current collector (110) can provide a reference surface on which the positive electrode active material layer (120) is arranged. The positive electrode current collector (110) can have a plate or foil shape. For example, the positive electrode current collector (110) can include 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.

[0032] Unlike that illustrated in FIG. 1A, in one embodiment of the present invention, the positive electrode current collector (110) may be omitted. Although not illustrated, a carbon layer having a thickness of 0.1 μm to 4 μm may be additionally disposed between the positive electrode current collector (110) and the positive electrode active material layer (120) to increase the bonding strength between the positive electrode current collector (110) and the positive electrode active material layer (120).

[0033] The cathode active material may be a material that can reversibly absorb and desorb lithium ions. For example, the cathode active material may include, but is not limited to, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide. The cathode active materials may be used alone or as a mixture of two or more thereof.

[0034] Lithium transition metal oxides include, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li a E 1-b Bb O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Co b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Mr b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Ni 1-b-c Mr b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni b HAVE BEEN c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Ni b Co c Mr d GeO2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG bO2(0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2GbO4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-f It may be a compound represented by any one of Fe2(PO4)3(0≤f≤2), LiFePO4. In these compounds, the capital letter “A” is Ni, Co, Mn, or a combination thereof, the capital letter “B” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof, the capital letter “D” is O, F, S, P, or a combination thereof, the capital letter “E” is Co, Mn, or a combination thereof, the capital letter “F” is F, S, P, or a combination thereof, the capital letter “G” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof, the capital letter “Q” is Ti, Mo, Mn, or a combination thereof, the capital letter “I” is Cr, V, Fe, Sc, Y, or a combination thereof, and the capital letter “J” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0035] The cathode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock salt type structure among the lithium transition metal oxides described above. The "layered rock salt type structure" is, for example, a cubic rock salt type structure. <111> It is a structure in which oxygen atomic layers and metal atomic layers are alternately and regularly arranged in a direction, and thereby each atomic layer forms a two-dimensional plane. The "cubic rock salt structure" refers to the sodium chloride type (NaCl type) structure, which is a type of crystal structure, and specifically refers to a structure in which the face-centered cubic lattice (fcc) formed by each cation and anion is arranged with a displacement of half of the ridge of the unit lattice. Lithium transition metal oxides having this layered rock salt structure include, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mn z O2(NCM) (0 <x<1,0<y<1, 0<z<1, x+y+z=1) 등의 삼원계 리튬전이금속산화물일 수 있다. 양극 활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 전고체 전지의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0036] The above-described compound included in the positive electrode active material may be covered by a coating layer (not shown). The positive electrode active material may also be a mixture of the above-described compound and a compound to which a coating layer is added. Meanwhile, the coating layer added to the surface of the positive electrode active material may include, for example, an oxide, a hydroxide, an oxyhydroxide, an oxycarbonate, or a hydroxycarbonate of the coating elements below. The compound forming the coating layer may be amorphous or crystalline. The coating elements included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO). The method for forming the coating layer may be selected within a range that does not adversely affect the physical properties of the positive electrode active material. The method for forming the coating layer may include, for example, a spray coating method or an immersion method.

[0037] When the positive electrode active material is a ternary lithium transition metal oxide such as NCA or NCM and contains nickel (Ni), the capacity density of the all-solid-state battery can be increased, which can reduce metal dissolution of the positive electrode active material in a charged state. As a result, the cycle characteristics of the all-solid-state battery in a charged state can be improved. Meanwhile, the “cycle characteristics” are characteristics indicating the degree to which the all-solid-state battery is deteriorated due to charge / discharge of the all-solid-state battery. An all-solid-state battery with high cycle characteristics can exhibit a small degree of deterioration due to charge / discharge, and an all-solid-state battery with low cycle characteristics can exhibit a large degree of deterioration due to charge / discharge.

[0038] The shape of the positive electrode active material may include particle shapes such as a sphere or an ellipsoid, for example. The particle size and content of the positive electrode active material are not particularly limited.

[0039] The solid electrolyte may have, for example, a particle shape. The solid electrolyte may be dispersed between positive electrode active materials. The solid electrolyte may include a sulfide-based solid electrolyte having excellent lithium ion conductivity characteristics. The sulfide-based solid electrolyte includes, for example, Li2S-P2S5, Li2S-P2S5-LiX (X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (m, n are positive numbers, capital letter “Z” represents Ge, Zn or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, capital letter “M” is one of P, Si, Ge, B, Al, Ga In), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may include at least one selected from (0≤x≤2).

[0040] Sulfide-based solid electrolytes include, for example, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I xIt may be an argyrodite-type compound including at least one selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0041] Alternatively, the sulfide-based solid electrolyte is Li 7-a M a PS 6-c X c It may be an argyrodite-type compound containing (0≤a≤2, (0≤c≤2)), where X may be F, Br, Cl, or a combination thereof. M is candium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or a combination thereof. Can be.

[0042] The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. Since the argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state battery is reduced, and the defect of the solid electrolyte membrane being penetrated and short-circuited due to the formation of lithium dendrites can be prevented. The elastic modulus of the solid electrolyte may be, for example, 15 GPa to 35 GPa.

[0043] The solid electrolyte included in the positive electrode active material layer (120) may have a smaller median particle size (D50) than the solid electrolyte included in the solid electrolyte layer (300) for an all-solid-state battery. For example, the median particle size (D50) of the solid electrolyte included in the positive electrode active material layer (120) may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the median particle size (D50) of the solid electrolyte included in the solid electrolyte layer (300) for an all-solid-state battery. Meanwhile, the median particle size (D50) may be a median diameter measured using a laser particle size distribution meter.

[0044] A metal having a strong ionization tendency may exist on the surface of the solid electrolyte included in the positive electrode active material layer (120). However, the content of the metal having a strong ionization tendency may be less than the content of the metal having a strong ionization tendency on the surface of the sulfide-based solid electrolyte of the solid electrolyte layer (300) for an all-solid-state battery. For example, the solid electrolyte in the positive electrode active material layer (120) may not include a metal having a strong ionization tendency, or even if it includes a metal having a strong ionization tendency, the content thereof may be less than that of the solid electrolyte layer (300) for an all-solid-state battery.

[0045] The positive electrode active material layer (120) may include a conductive material. The conductive material may have conductivity without causing chemical changes in the all-solid-state battery, thereby increasing the conductivity of the positive electrode active material and the solid electrolyte. The conductive material may include a carbon-based material. For example, the conductive material may include one or more selected from graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0046] The positive electrode active material layer (120) may further include a binder. The binder may include a material for binding the positive electrode active material, solid electrolyte, and conductive material included in the positive electrode active material layer (120) and improving bonding strength with the positive electrode current collector (110). For example, the binder may include polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, or polymethyl methacrylate.

[0047] When the total amount of the positive electrode active material, the solid electrolyte, the conductive material, and the binder is 100 parts by weight, the positive electrode active material layer (120) may include 85 parts by weight to 92 parts by weight of the positive electrode active material. The positive electrode active material layer (120) may include 0.5 parts by weight to 1.5 parts by weight of the binder.

[0048] Within the positive electrode active material layer (120), the conductive material may be present in an amount of 1 to 50 parts by weight relative to 100 parts by weight of the solid electrolyte. If the conductive material is present in an amount less than 1 part by weight relative to 100 parts by weight of the solid electrolyte, the electrical conductivity of the positive electrode active material layer (120) may be reduced. If the conductive material is present in an amount greater than 50 parts by weight relative to 100 parts by weight of the solid electrolyte, the conductive material ratio may be excessively high, and thus a covering layer covering the surface of the solid electrolyte may not be properly formed.

[0049] According to embodiments, the positive electrode active material layer (120) may further include at least one additive selected from the group consisting of a filler, a coating agent, a dispersant, and an ion conductive auxiliary agent in addition to the above-described positive electrode active material, solid electrolyte, conductive agent, and binder.

[0050] The solid electrolyte layer (300) for an all-solid-state battery is disposed between the positive electrode layer (100) and the negative electrode layer (200) and may include a sulfide-based solid electrolyte having excellent lithium ion conductivity characteristics. The solid electrolyte layer (300) may include a solid electrolyte, a binder, etc. The solid electrolyte may include an argyrodite-type compound. The solid electrolyte included in the solid electrolyte layer (300) may be the same as or different from any one of the materials that may be included in the solid electrolyte included in the positive electrode active material layer (120) described above.

[0051] The solid electrolyte may include, for example, the solid electrolyte described above. For convenience of explanation, the same details as those described above will be omitted below, and differences will be described in detail.

[0052] The binder in the solid electrolyte layer (300) may be, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited thereto. The binder of the solid electrolyte layer (300) may be the same as or different from the binder included in the positive electrode active material layer (120) or the binder included in the negative electrode coating layer (220).

[0053] The negative electrode layer (200) may include a negative electrode current collector (210) and a negative electrode coating layer (220) on the negative electrode current collector (210). The negative electrode current collector (210) may provide a reference surface on which the negative electrode coating layer (220) is disposed. The negative electrode current collector (210) may include, for example, a material that does not react with lithium, i.e., does not form an alloy or a compound with lithium. For example, the negative electrode current collector (210) may include at least one metal selected from the group consisting of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The thickness of the negative electrode current collector (210) may be 1 μm to 20 μm, more specifically 5 μm to 15 μm, and more specifically 7 μm to 10 μm.

[0054] The negative electrode current collector (210) may be composed of one of the above-described metals, or may include an alloy or coating material of two or more metals. The negative electrode current collector (210) may have, for example, a plate shape or a foil shape. Meanwhile, in one embodiment, the negative electrode current collector (210) may be omitted.

[0055] The negative electrode coating layer (220) can allow lithium metal to grow between it and the negative electrode current collector (210) when the all-solid-state battery is charged. The negative electrode coating layer (220) can act as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0056] The cathode coating layer (220) may include a metal and carbon. For example, the cathode coating layer (220) may include at least one metal selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The cathode coating layer (220) may include at least one carbon selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene. In one embodiment, the cathode coating layer (220) may include a mixture of carbon black and silver (Ag).

[0057] The cathode coating layer (220) may further include additives other than metal and carbon. The cathode coating layer (220) may further include, for example, at least one additive selected from the group consisting of a binder, a filler, a coating agent, a dispersant, and an ion conductive additive.

[0058] The negative electrode coating layer (220) may have a smaller thickness than the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 1 um to 20 um, 2 um to 10 um, or 3 um to 7 um. If the thickness of the negative electrode coating layer (220) is too thin, lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210) may cause the negative electrode coating layer (220) to collapse, thereby deteriorating the cycle characteristics of the all-solid-state battery. If the thickness of the cathode coating layer (220) increases excessively, the energy density of the all-solid-state battery may decrease and the internal resistance of the all-solid-state battery due to the cathode coating layer (220) may increase, thereby deteriorating the cycle characteristics of the all-solid-state battery.

[0059] Meanwhile, although not shown, a carbon layer may be further included to improve adhesion between the cathode coating layer (220) and the solid electrolyte layer (300).

[0060]

[0061] Referring to FIG. 1B, the negative electrode layer (200) may include a negative electrode current collector (210) and a negative electrode active material layer (230) disposed on the negative electrode current collector (210). The negative electrode active material layer (230) may include a negative electrode active material and a binder. The negative electrode active material included in the negative electrode active material layer (230) may have a particle form. The median particle size average particle diameter (D50) of the negative electrode active material having a particle form may be, for example, 4 μm or less, 2 μm or less, 1 μm or less, or 900 nm or less. The median particle size average particle diameter (D50) of the negative electrode active material may be, for example, 10 nm to 4 μm, 10 nm to 2 μm, or 10 nm to 900 nm. When the negative electrode active material has a median particle size (D50) within this range, reversible absorption and / or desorption of lithium may be facilitated during charge and discharge. Meanwhile, the median particle size (D50) may be a median diameter measured using a laser particle size distribution meter.

[0062] The negative electrode active material may include, for example, at least one selected from a carbon-based negative electrode active material and a metal or metalloid negative electrode active material.

[0063] The carbon-based negative electrode active material may be amorphous carbon, in particular. Examples of amorphous carbon include, but are not limited to, carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), and graphene. Amorphous carbon is carbon that has no crystallinity or very low crystallinity, and is distinguished from crystalline carbon or graphitic carbon.

[0064] The metal or metalloid negative electrode active material includes, but is not necessarily limited to, one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn), and may be a metal negative electrode active material or a metalloid negative electrode active material that forms an alloy or compound with lithium. On the other hand, nickel (Ni) does not form an alloy with lithium and therefore is not a metal negative electrode active material.

[0065] The negative electrode active material layer (230) includes one type of negative electrode active material among these negative electrode active materials, or includes a mixture of a plurality of different negative electrode active materials. For example, the negative electrode active material layer (230) may include only amorphous carbon, or may include one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).

[0066] In one embodiment, the negative electrode active material layer (230) may include a mixture of amorphous carbon and one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The mixing ratio of the mixture of amorphous carbon and gold (Au), etc., may be, for example, 10:1 to 1:2, 5:1 to 1:1, or 4:1 to 2:1 by weight, but is not necessarily limited to this range and may be selected according to the characteristics of the required all-solid-state battery. When the negative electrode active material has this composition, the cycle characteristics of the all-solid-state battery can be further improved.

[0067] The binder included in the negative electrode active material layer (230) may be, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited thereto. The binder may include a single binder or a plurality of different binders.

[0068] Since the negative electrode active material layer (230) includes a binder, the negative electrode active material layer (230) can be stably formed on the negative electrode current collector (210). That is, the bonding strength between the negative electrode active material layer (230) and the negative electrode current collector (210) can be increased. In addition, cracking of the negative electrode active material layer (230) is suppressed despite changes in the volume and / or relative positions of the negative electrode active material layer (230) during the charge and discharge process. If the negative electrode active material layer (230) does not include a binder, the negative electrode active material layer (230) can be easily separated from the negative electrode current collector (210). As the negative electrode active material layer (230) is detached from the negative electrode current collector (210), the negative electrode current collector (210) can come into contact with the solid electrolyte layer at the exposed portion, thereby increasing the possibility of a short circuit occurring.

[0069] The negative electrode active material layer (230) is manufactured, for example, by providing a mixture in which the materials constituting the negative electrode active material layer (230) are dispersed onto the negative electrode current collector (210). Since a binder is included in the materials constituting the negative electrode active material layer (230), stable dispersion of the negative electrode active material in the mixture is possible. For example, when applying the mixture onto the negative electrode current collector (210) by screen printing, it is possible to suppress clogging of the screen (e.g., clogging by aggregates of the negative electrode active material) by the binder.

[0070] The negative electrode active material layer (230) may further include other additives in addition to the negative electrode active material and binder. The negative electrode active material layer (230) may further include, for example, fillers, coating agents, dispersants, ion conductive additives, etc.

[0071] The negative electrode active material layer (230) may have a smaller thickness than the positive electrode active material layer (120). The thickness of the negative electrode active material layer (230) may be, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer (120). The thickness of the negative electrode active material layer (230) may be, for example, 1 um to 20 um, 2 um to 10 um, or 3 um to 7 um. If the thickness of the negative electrode active material layer (230) is too thin, lithium dendrites formed between the negative electrode active material layer (230) and the negative electrode current collector (210) may collapse the negative electrode active material layer (230), thereby deteriorating the cycle characteristics of the all-solid-state battery. If the thickness of the negative electrode active material layer (230) increases excessively, the energy density of the all-solid-state battery may decrease and the internal resistance of the all-solid-state battery due to the negative electrode active material layer (230) may increase, thereby deteriorating the cycle characteristics of the all-solid-state battery.

[0072] If the thickness of the negative electrode active material layer (230) decreases, the charge capacity of the negative electrode active material layer (230) may also decrease, for example. The charge capacity of the negative electrode active material layer (230) is, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, 5% or less, or 2% or less than the charge capacity of the positive electrode active material layer (120). The charge capacity of the negative electrode active material layer (230) is, for example, 0.1% to 50%, 0.1% to 40%, 0.1% to 30%, 0.1% to 20%, 0.1% to 10%, 0.1% to 5%, or 0.1% to 2% than the charge capacity of the positive electrode active material layer (120). If the charge capacity of the negative electrode active material layer (230) is excessively small, the thickness of the negative electrode active material layer (230) becomes very thin, and the same defects as the defects described above that occur when the thickness of the negative electrode active material layer (230) becomes excessively thin may occur. If the charge capacity of the negative electrode active material layer (230) increases excessively, the same defects as the defects described above that occur when the thickness of the negative electrode active material layer (230) increases excessively may occur.

[0073] The charge capacity of the positive electrode active material layer (120) can be obtained by multiplying the charge capacity density (mAh / g) of the positive electrode active material by the mass of the positive electrode active material of the positive electrode active material layer (120). When the positive electrode active material layer (120) includes several types of positive electrode active materials, the [charge capacity density Х mass] value is calculated for each positive electrode active material, and the sum of these values ​​of the positive electrode active materials is the charge capacity of the positive electrode active material layer (120). The charge capacity of the negative electrode active material layer (230) can also be calculated in the same way. That is, the charge capacity of the negative electrode active material layer (230) is obtained by multiplying the charge capacity density (mAh / g) of the negative electrode active material by the mass of the negative electrode active material in the negative electrode active material layer (230). When the negative electrode active material layer (230) includes several types of negative electrode active materials, the [charge capacity density Х mass] value is calculated for each negative electrode active material, and the sum of these values ​​of the negative electrode active materials is the capacity of the negative electrode active material layer (230). Here, the charge capacity density of the positive electrode active material and the negative electrode active material may be an estimated capacity using an all-solid-state half-cell using lithium metal as a counter electrode. The charge capacity of the positive electrode active material layer (120) and the negative electrode active material layer (230) can be directly measured by measuring the charge capacity using the all-solid-state half-cell. The charge capacity density can be obtained by dividing the measured charge capacity by the mass of each active material. Meanwhile, in the present specification, the “charge capacity” of the positive electrode active material layer (120) and the negative electrode active material layer (230) means the initial charge capacity measured at the time of the first cycle charge.

[0074] Meanwhile, although not shown, a carbon layer may be further included to improve adhesion between the negative electrode active material layer (230) and the solid electrolyte layer (300).

[0075] An all-solid-state battery according to one embodiment of the present invention can be applied to automobiles, mobile phones, and / or various types of electrical devices, but the present invention is not limited thereto.

[0076]

[0077] Pretreatment method for all-solid-state batteries

[0078] FIG. 2 is a flowchart illustrating a method for pretreating an all-solid-state battery according to one embodiment of the present invention, and FIG. 3 is a schematic diagram illustrating a pretreating device for an all-solid-state battery according to one embodiment of the present invention. Hereinafter, with reference to FIGS. 2 and 3, a method for pretreating an all-solid-state battery according to one embodiment of the present invention will be examined in more detail.

[0079] Referring to FIGS. 2 and 3, a method for pretreatment of an all-solid-state battery according to one embodiment of the present invention may include immersing waste (1) of an all-solid-state battery in oil (2) (S10), physically decomposing the waste (1) while immersed in the oil (2) (S20), and obtaining a decomposed product (3). As a result, the waste (1) of an all-solid-state battery can be safely pretreated and completely discharged at the same time.

[0080] Immersing waste (1) of an all-solid-state battery in oil (2) (S10) may include immersing an all-solid-state battery that has reached the end of its life and is discarded or waste generated during the manufacturing process of an all-solid-state battery in oil (2).

[0081] The waste (1) of the above-mentioned all-solid-state battery may be at least one of a battery cell, a battery module, a battery pack, and process scrap. The battery cell may have a cylindrical, square, pouch-shaped, or coin-shaped shape. The battery module may include a plurality of battery cells. The battery pack includes a plurality of battery modules and may include various control and protection systems such as a BMS (Battery Management System), a cooling system, and the like. The process scrap may be waste generated during the manufacturing process of the all-solid-state battery.

[0082] The above oil (2) can be filled inside the chamber (10), as shown in Fig. 3. The above oil (2) can serve to block the battery waste (1) from being exposed to moisture and oxygen in the air.

[0083] The above oil (2) may include at least one selected from mineral oil, silicone oil, vegetable oil, and synthetic oil. Preferably, mineral oil may be used as the oil (2).

[0084] The mineral oil mentioned above is called mineral oil and may be a type of by-product of the crude oil refining process. The mineral oil may be a liquid mixture of hydrocarbons having 10 to 50 carbon atoms. The mineral oil may include paraffinic oil, naphthenic oil, aromatic oil, or a mixture thereof.

[0085] The above silicone oil may be a silicone oil without a hydroxyl group at the molecular terminal.

[0086] The vegetable oil may be, for example, soybean oil, palm oil, palm oil, cottonseed oil, camellia oil, or hydrogenated oil.

[0087] The above synthetic oil may be, for example, PAO (Polyalphaolefins) synthetic oil, ester-based synthetic oil, etc.

[0088] The type of the above oil (2) is not limited as long as it contains substantially little or no moisture while blocking contact with oxygen.

[0089] The moisture content of the oil (2) containing substantially no moisture may be 100 ppm or less. Specifically, the moisture content in the oil (2) is preferably 10 ppm or less. For example, the moisture content in the oil (2) may be 1 ppm to 7 ppm, 3 ppm to 7 ppm, or 3 ppm to 9 ppm.

[0090] If the moisture content in the above oil (2) exceeds 100 ppm, there may be a problem in which hydrogen sulfide (H2S), a toxic gas, is generated due to a side reaction between sulfur contained in the battery waste (1) and moisture contained in the oil (2).

[0091] In the present invention, substantially containing little moisture may mean that there is substantially no generation of hydrogen sulfide (H2S) due to a reaction between sulfur in the battery waste (1) and moisture in the oil (2).

[0092] According to one embodiment of the present invention, the decomposition process described below is performed while the battery waste (1) is immersed in the oil (2), thereby fundamentally blocking the generation of hydrogen sulfide (H2S). This provides a pretreatment method with improved moisture stability.

[0093] The above oil (2) may be recovered and reused. Although not separately illustrated in FIG. 3, an extraction unit (not shown) for recovering the oil (2) may be provided. According to one embodiment of the present invention, a more economical and environmentally friendly pretreatment method can be provided by reusing the oil (2) without continuously consuming it.

[0094] Referring to FIG. 3, the decomposition (S20) may include physically decomposing the battery waste (1) through a decomposition means (20).

[0095] The above-mentioned decomposition means (20) is a means for decomposing the battery waste (1), and can be provided inside the chamber (10) while being immersed in the oil (2).

[0096] The above decomposition (S20) can perform at least one of crushing, pulverization, pressurization, and penetration.

[0097] According to one embodiment of the present invention, the physical decomposition is to decompose relatively large battery waste (1) into relatively small sizes by applying mechanical energy such as impact force, compression force, frictional force, shear force, or cutting force.

[0098] In this specification, the term “crushing” means crushing battery waste (1) into sizes of 1 mm to 100 mm.

[0099] In this specification, the term “crushing” means crushing battery waste (1) into a size of 100 μm to 1 mm or less.

[0100] In this specification, the term “pressurization” means applying a predetermined pressure to battery waste (1) to compress it to a certain size or less.

[0101] The term “penetrating” in this specification may refer to cutting by making a hole in the battery waste (1). For example, piercing may include making a hole in the battery waste (1) (puncturing), saw blade cutting, mechanically piercing, etc.

[0102] The above decomposing (S20) can be performed using at least one selected from the group consisting of a jaw crusher, a cone crusher, a roll crusher, a hammer mill, a cut mill, a pin mill, an impact mill, a ball mill, and a shredder. The type of the decomposing means (20) is not particularly limited as long as it can decompose the battery waste (1) by applying mechanical energy. In one embodiment, the decomposing means (20) can be a jaw crusher.

[0103] By decomposing the battery waste (1) through the above decomposition means (20), the decomposition result (3) can be obtained.

[0104] The above decomposition result (3) may be in the form of a powder having an average particle size of 1 mm to 10 mm. However, the average particle size of the decomposition result (3) is not particularly limited. The average particle size of the decomposition result (3) may be, for example, 1 mm to 500 mm, 1 mm to 300 mm, 1 mm to 100 mm, 1 mm to 50 mm, or 1 mm to 10 mm.

[0105] The "average particle diameter" used in the present invention may be the diameter (D50) of particles having a cumulative volume of 50% by volume in a particle size distribution. For example, the average particle diameter of the decomposition product (3) may be the median diameter (D50) measured using a laser particle size distribution meter.

[0106] The average particle size (D50) can be measured using methods widely known to those skilled in the art. For example, it can be measured using a particle size analyzer, using a transmission electron microscope (TEM) or scanning electron microscope (SEM) image, or using a length measuring device such as a tape measure.

[0107] The above decomposition result (3) may include precious metals such as Co, Ni, Mn and Li, negative electrode materials including graphite, impurities such as Al, Cu and Fe, and solid electrolytes. The above decomposition result (3) may include various substances depending on the type of battery waste (1).

[0108] In addition, the density of the decomposition product (3) may be higher than the density of the oil (2). Accordingly, the decomposition product (3) may be deposited within the chamber (10). The decomposition product (3) may be stored or transported in a state of being deposited in the oil (2) described above for later use as a recycled raw material.

[0109]

[0110] A pretreatment method according to one embodiment of the present invention can prevent explosion or fire by physically decomposing battery waste while immersed in oil. The present invention can provide a pretreatment method with improved moisture stability by suppressing side reactions between battery waste and moisture due to the use of oil. Furthermore, the present invention can reduce process costs because it uses relatively inexpensive oil. Consequently, one embodiment of the present invention can pretreat all-solid-state battery waste through a more environmentally friendly, economical, and safe method.

[0111] The present invention performs a pretreatment process on all-solid-state battery cells, modules, packs, or process scraps, thereby omitting a separate process for disassembling modules and packs, thereby enabling easier pretreatment of all-solid-state battery waste.

[0112]

[0113] Pretreatment device for all-solid-state batteries

[0114] Figure 3 is a schematic diagram illustrating a pretreatment device for an all-solid-state battery according to one embodiment of the present invention.

[0115] A pretreatment device according to one embodiment of the present invention can perform the pretreatment process of the above-described all-solid-state battery waste.

[0116] Referring to FIG. 3, a pretreatment device according to one embodiment of the present invention may include a chamber (10); and a decomposition means (20) provided inside the chamber (10) to decompose battery waste (1).

[0117] The chamber (10) above can be filled with oil (2) inside.

[0118] The above-described decomposition means (20) may be provided inside a chamber (10) filled with the oil (2). That is, as described above, the decomposition means (20) can physically decompose battery waste (1) while immersed in the oil (2). As a result, battery waste (1) can be safely pretreated while being prevented from contact with moisture and oxygen.

[0119]

[0120] Method for recovering cathode active material precursor and solid electrolyte

[0121] A method for recovering a cathode active material precursor and a solid electrolyte according to one embodiment of the present invention may include recovering the cathode active material precursor and the solid electrolyte from the pretreated resultant product by performing the aforementioned pretreatment process for all-solid-state battery waste. A detailed description of the cathode active material and the solid electrolyte will be omitted as they have been described with reference to FIG. 1.

[0122] The above-described method for recovering the positive electrode active material precursor and solid electrolyte can be applied to recovery processes widely used in the art, such as classification, acid leaching, and filtration. This allows the positive electrode active material precursor and solid electrolyte to be recycled. For example, the pretreated product can be recycled as a smelting raw material in a dry recycling process for lithium secondary batteries after undergoing the aforementioned recovery process.

[0123]

[0124] While embodiments of the present invention have been described with reference to the attached drawings, the present invention may be implemented in other specific forms without altering the technical spirit or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. Immersing the waste from the all-solid-state battery in oil; Physically decomposing the above waste while immersing it in the above oil; and Obtaining a decomposed product; including; The above waste is at least one of battery cells, battery modules, battery packs and process scrap, The oil comprises at least one selected from mineral oil, silicone oil, vegetable oil and synthetic oil. A pretreatment method for an all-solid-state battery.

2. In paragraph 1, The above disassembling is performed by performing at least one of crushing, pulverizing, pressurizing and penetrating. A pretreatment method for an all-solid-state battery.

3. In paragraph 1, The above decomposition is performed using at least one selected from the group consisting of a jaw crusher, a cone crusher, a roll crusher, a hammer mill, a cut mill, a pin mill, an impact mill, a ball mill and a shredder. A pretreatment method for an all-solid-state battery.

4. In paragraph 1, The density of the above decomposition product is higher than the density of the oil. A pretreatment method for an all-solid-state battery.

5. In paragraph 1, The above decomposition result has an average particle size of 1 mm to 10 mm, A pretreatment method for an all-solid-state battery.

6. In paragraph 1, The above oil is recovered and reused. A pretreatment method for an all-solid-state battery.

7. In paragraph 1, The above mineral oil includes paraffinic oil, naphthenic oil, aromatic oil or a mixture thereof. A pretreatment method for an all-solid-state battery.

8. In paragraph 1, The above oil contains less than 100 ppm of moisture, A pretreatment method for an all-solid-state battery.

9. In paragraph 1, The above decomposition result is stored and transported in a precipitated state in the oil. A pretreatment method for an all-solid-state battery.

10. A chamber filled with oil; and a decomposition means; Pretreating all-solid-state battery waste according to any one of the methods of Articles 1 to 9; Pretreatment device for all-solid-state batteries.

11. In paragraph 10, The oil comprises at least one selected from mineral oil, silicone oil, vegetable oil and synthetic oil. Pretreatment device for all-solid-state batteries.

12. In paragraph 11, The above mineral oil includes paraffinic oil, naphthenic oil, aromatic oil or a mixture thereof. Pretreatment device for all-solid-state batteries.

13. In paragraph 10, The above oil contains less than 100 ppm of moisture, Pretreatment device for all-solid-state batteries.

14. In paragraph 10, The above decomposition means is at least one selected from the group consisting of a jaw crusher, a cone crusher, a roll crusher, a hammer mill, a cut mill, a pin mill, an impact mill, a ball mill and a shredder. Pretreatment device for all-solid-state batteries.

15. Providing a preprocessed result according to any one of the methods of paragraphs 1 to 9; and Recovering a positive electrode active material precursor and a solid electrolyte from the above result; Method for recovering a cathode active material precursor and a solid electrolyte.

16. In paragraph 15, The positive electrode active material comprises at least one selected from the group consisting of lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, lithium iron phosphate, and combinations thereof. Method for recovering a cathode active material precursor and a solid electrolyte.

17. In paragraph 15, The above solid electrolyte is a sulfide-based solid electrolyte. Method for recovering a cathode active material precursor and a solid electrolyte.

18. In paragraph 17, The above sulfide-based solid electrolyte is Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x Comprising an argyrodite-type compound comprising at least one selected from (0≤x≤2), Method for recovering a cathode active material precursor and a solid electrolyte.

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