Device and method for detecting ionic conductivity of solid-state battery monomer electrode

Abstract

The invention provides a device and a method for detecting the ionic conductivity of a solid-state battery monomer electrode, the device comprises a mold assembly, an electrochemical workstation and a press assembly, the mold assembly comprises a mold structure and a solid-state battery monomer electrode assembly to be detected; the mold structure comprises a mold sleeve, a first electrode column, an insulating spacer, an insulating sleeve and a second electrode column, the mold sleeve is provided with a first opening and a second opening which are oppositely arranged, the first electrode column is used for being inserted into the first opening, a protruding part is arranged at the end, facing the second opening, of the first electrode column, and the insulating spacer is arranged on the first electrode column and surrounds the protruding part; the insulating sleeve is inserted into the mold sleeve through the second opening, and the second electrode column is inserted into the insulating sleeve. According to the invention, the consistency and the accuracy of the test result of the solid-state battery monomer electrode ion conductivity can be improved.

Description

Technical Field

[0001] This disclosure relates to an apparatus and method for detecting the ionic conductivity of a solid-state battery cell electrode. Background Technology

[0002] Ion conductivity is one of the key indicators of solid-state battery cell electrodes. Taking the positive electrode as an example, the positive electrode of a solid-state battery cell is usually a composite positive electrode composed of positive electrode active material, solid electrolyte material, and positive electrode conductive agent. Electrochemical reactions only occur at the three-phase contact interface of the positive electrode active material, solid electrolyte material, and positive electrode conductive agent. Contact loss in any phase will affect the performance of the solid-state battery cell. In addition, the positive electrode of a solid-state battery cell may also include a positive electrode binder, which can hinder ion transport in the positive electrode. Therefore, it is necessary to accurately test the ionic conductivity of solid-state battery cell electrodes to better guide electrode design and improve the performance of solid-state battery cells. Summary of the Invention

[0003] This disclosure provides an apparatus and method for detecting the ionic conductivity of a solid-state battery cell electrode, which can improve the consistency and accuracy of the test results of the ionic conductivity of a solid-state battery cell electrode.

[0004] In a first aspect, this disclosure provides an apparatus for detecting the ionic conductivity of a solid-state battery cell electrode. The apparatus includes a mold assembly, an electrochemical workstation, and a press assembly. The press assembly is used to apply pressure to the mold assembly. The electrochemical workstation is electrically connected to the mold assembly and forms a detection circuit. The mold assembly includes a mold structure and a solid-state battery cell electrode assembly to be tested. The mold structure is used to accommodate the solid-state battery cell electrode assembly to be tested.

[0005] The mold structure includes: a mold sleeve, a first electrode post, an insulating gasket, an insulating sleeve, and a second electrode post. The mold sleeve has a first opening and a second opening that are disposed opposite to each other. The first electrode post is used to insert into the first opening, and a protrusion is provided at one end of the first electrode post facing the second opening. The insulating gasket is disposed on the first electrode post and surrounds the protrusion. The insulating sleeve is used to insert into the mold sleeve through the second opening. The second electrode post is used to insert into the insulating sleeve.

[0006] The electrode assembly of the solid-state battery cell under test includes an electrode under test, a first solid electrolyte sheet, a second solid electrolyte sheet, a first lithium alloy electrode, and a second lithium alloy electrode. The electrode under test is located between the first solid electrolyte sheet and the second solid electrolyte sheet. The first lithium alloy electrode is located between the first solid electrolyte sheet and the first electrode post. The second lithium alloy electrode is located between the second solid electrolyte sheet and the second electrode post. The first solid electrolyte sheet and the electrode under test are pressed into sheet shape in a mold sleeve and housed in the mold sleeve. The second solid electrolyte sheet is pressed into sheet shape in an insulating sleeve and housed in the insulating sleeve. The first lithium alloy electrode is housed in the cavity formed by the insulating pad surrounding the protrusion, and the second lithium alloy electrode is housed in the insulating sleeve.

[0007] This disclosure, by introducing an insulating sleeve into the mold sleeve, can avoid short circuits in the system under test, thereby improving the consistency and accuracy of the solid-state battery cell electrode ion conductivity test results.

[0008] In some embodiments, the projections of the first lithium alloy electrode, the second solid electrolyte sheet, and the second lithium alloy electrode overlap.

[0009] In some embodiments, the ionic conductivity of the first solid electrolyte sheet at 25°C is greater than or equal to 1×10⁻⁶. - 3 S / cm, electronic conductivity at 25℃ less than or equal to 1×10⁻⁶ -9 S / cm.

[0010] In some embodiments, the ionic conductivity of the second solid electrolyte sheet at 25°C is greater than or equal to 1×10⁻⁶. - 3 S / cm, electronic conductivity at 25℃ less than or equal to 1×10⁻⁶ -9 S / cm.

[0011] In some embodiments, the first lithium alloy electrode is a lithium indium alloy electrode.

[0012] In some embodiments, the second lithium alloy electrode is a lithium indium alloy electrode.

[0013] In some embodiments, the first solid electrolyte sheet and the second solid electrolyte sheet each independently include one or more of sulfide solid electrolyte materials, halide solid electrolyte materials, and oxide solid electrolyte materials.

[0014] In some embodiments, the electrode under test is a positive electrode, which includes a positive electrode active material, a solid electrolyte material, and a positive electrode conductive agent.

[0015] In some embodiments, the electrode under test is a negative electrode, which includes a negative electrode active material, a solid electrolyte material, and a negative electrode conductive agent.

[0016] In some embodiments, the press assembly includes a first hydraulic plate and a second hydraulic plate disposed opposite to each other, the first hydraulic plate and the second hydraulic plate being used to apply pressure to both ends of the mold assembly.

[0017] In a second aspect, this disclosure provides a method for detecting the ionic conductivity of a solid-state battery cell electrode using the apparatus of the first aspect, comprising the following steps: surrounding and assembling an insulating pad around the protrusion of a first electrode post to obtain a first electrode post with the insulating pad; subsequently inserting the first electrode post with the insulating pad into a first opening of a mold sleeve; placing first solid electrolyte material powder into the mold sleeve through a second opening; inserting a movable electrode post into the mold sleeve through the second opening; and pressing the first solid electrolyte material powder into a first solid electrolyte sheet in the mold sleeve; removing the movable electrode post; placing the electrode powder to be tested into the mold sleeve through the second opening; inserting the movable electrode post into the mold sleeve through the second opening; and pressing the electrode powder to be tested into a test electrode in the mold sleeve; removing the movable electrode post; and so on. The process involves inserting an insulating sleeve into the mold sleeve through a second opening; placing a second solid electrolyte material powder into the insulating sleeve through an opening; inserting a second electrode post into the insulating sleeve through an opening and pressing the second solid electrolyte material powder into a second solid electrolyte sheet within the insulating sleeve; removing the first and second electrode posts equipped with insulating pads; placing a first lithium alloy electrode and a second lithium alloy electrode outside the first and second solid electrolyte sheets, respectively; then inserting the first and second electrode posts equipped with insulating pads to assemble a mold assembly; applying pressure to the mold assembly using a press assembly and maintaining the pressure; electrically connecting the mold assembly to an electrochemical workstation to form a detection circuit; and using the electrochemical workstation to test the ionic conductivity of the electrode under test by electrochemical impedance spectroscopy (EIS). Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are merely some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the drawings without any creative effort.

[0019] Figure 1A schematic diagram of a detection apparatus provided in some embodiments of this disclosure is shown.

[0020] Figure 2 An exploded schematic diagram of a mold structure provided in some embodiments of this disclosure is shown.

[0021] Figure 3 An exploded view of the electrode assembly of a solid-state battery cell under test provided in some embodiments of this disclosure is shown.

[0022] Figure 4 This diagram illustrates the structure of a mold assembly after pressing, according to some embodiments of this disclosure.

[0023] Figure 5 An exploded view of the existing mold structure is shown.

[0024] The accompanying drawings are not necessarily drawn to scale.

[0025] The reference numerals in the attached figures are explained as follows: 1. Mold assembly; 2. Electrochemical workstation; 3. Press assembly; 10. Mold structure; 11. Mold sleeve; 12. First electrode post; 13. Insulating gasket; 14. Insulating sleeve; 15. Second electrode post; 20. Electrode assembly of the solid-state battery cell under test; 21. Electrode under test; 22. First solid electrolyte sheet; 23. Second solid electrolyte sheet; 24. First lithium alloy electrode; 25. Second lithium alloy electrode; 111. Lower electrode post; 112. Upper electrode post. Detailed Implementation

[0026] The following detailed description, with appropriate reference to the accompanying drawings, provides a specific embodiment of the apparatus and method for detecting the ionic conductivity of a solid-state battery cell electrode according to this disclosure. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter of the claims.

[0027] The "range" disclosed in this disclosure is defined by a lower limit and an upper limit, whereby a given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this disclosure, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0028] Unless otherwise specified, all embodiments and optional embodiments of this disclosure may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of this disclosure.

[0029] Unless otherwise specified, all technical features and optional technical features of this disclosure can be combined to form new technical solutions, and such technical solutions should be considered as included in the disclosure of this disclosure.

[0030] Unless otherwise specified, all steps in this disclosure may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0031] Unless otherwise specified, in this disclosure, the terms "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0032] In this disclosure, the terms "multiple" or "a variety" refer to two or more kinds.

[0033] In the description of the embodiments of this disclosure, unless otherwise specified, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0034] Unless otherwise stated, the test temperature for all parameters mentioned in this disclosure is 25°C.

[0035] In solid-state battery cell electrodes, studying the structure-property relationships of active materials, conductive agents, binders, and solid electrolyte materials—including their types, morphologies, and amounts—on electrode capacity and kinetic performance, and establishing a multi-component matching paradigm, is crucial for the practical application of solid-state battery cells. Testing the ionic and electronic conductivity of the electrode can reflect the compatibility between its multiple components, thus guiding electrode design and optimizing the performance of solid-state battery cells.

[0036] Typically, the electronic conductivity of an electrode can be easily and accurately measured using electrochemical impedance spectroscopy. However, accurate measurement of the ionic conductivity requires additional control. This is because the electronic conductivity of an electrode is usually much higher than its ionic conductivity. To accurately measure the ionic conductivity of an electrode, it is generally necessary to block electron transport in the test system. To achieve this blocking, an electron-blocking electrode needs to be constructed. The key to the electron-blocking electrode method lies in constructing a "solid electrolyte sheet | analyte | solid electrolyte sheet" sandwich structure. In this sandwich structure, the solid electrolyte sheet can provide high ionic conductivity and low electronic conductivity. Thus, this sandwich structure can block electron transport in the analyte while ensuring efficient ion transport.

[0037] Currently, the method for measuring electrode ionic conductivity using the electronic blocking electrode method typically includes the following steps: First, a certain mass of the electrode powder to be tested is added to a mold sleeve, and the electrode is pressed into a test electrode sheet using an electrode column; a certain mass of solid electrolyte material powder is added to both sides of the test electrode sheet, and then the electrode is pressed into a solid electrolyte sheet using an electrode column; then, electrodes such as lithium indium alloy sheets are placed on the outside of the solid electrolyte sheets on both sides of the mold sleeve, and the electrode columns are installed on both sides of the mold sleeve; then, a certain pressure is applied to the electrode columns on both sides of the mold sleeve using a press, and the electrode columns are electrically connected to an electrochemical workstation to form a detection circuit, which allows for electrochemical impedance spectroscopy (EIS) testing to obtain the ionic conductivity of the electrode powder to be tested.

[0038] However, when the electrode powder to be tested is loaded into the mold sleeve, due to the presence of electrostatic effect, the conductive agent powder is very easy to adhere to the inner wall of the mold sleeve. This will cause a short circuit in the "solid electrolyte sheet | test material | solid electrolyte sheet" sandwich structure, which will lead to a decrease in the consistency and accuracy of the ionic conductivity test results of the electrode powder to be tested.

[0039] Based on this, the present disclosure provides an apparatus for detecting the ionic conductivity of a solid-state battery cell electrode.

[0040] like Figures 1 to 4 As shown, the device for detecting the ionic conductivity of a solid-state battery cell electrode includes a mold assembly 1, an electrochemical workstation 2, and a pressure assembly 3. The pressure assembly 3 applies pressure to the mold assembly 1. The electrochemical workstation 2 is electrically connected to the mold assembly 1 and forms a detection circuit. The mold assembly 1 includes a mold structure 10 and a solid-state battery cell electrode assembly 20 to be tested. The mold structure 10 is used to accommodate the solid-state battery cell electrode assembly 20 to be tested.

[0041] The mold structure 10 includes a mold sleeve 11, a first electrode post 12, an insulating gasket 13, an insulating sleeve 14, and a second electrode post 15. The mold sleeve 11 has a first opening and a second opening that are disposed opposite to each other; the first electrode post 12 is inserted into the first opening, and a protrusion is provided at one end of the first electrode post 12 facing the second opening; the insulating gasket 13 is disposed on the first electrode post 12 and surrounds the protrusion; the insulating sleeve 14 is inserted into the mold sleeve 11 through the second opening; and the second electrode post 15 is inserted into the insulating sleeve 14.

[0042] The solid-state battery cell electrode assembly 20 under test includes an electrode under test 21, a first solid electrolyte sheet 22, a second solid electrolyte sheet 23, a first lithium alloy electrode 24, and a second lithium alloy electrode 25. The electrode under test 21 is located between the first solid electrolyte sheet 22 and the second solid electrolyte sheet 23, the first lithium alloy electrode 24 is located between the first solid electrolyte sheet 22 and the first electrode post 12, and the second lithium alloy electrode 25 is located between the second solid electrolyte sheet 23 and the second electrode post 15.

[0043] The first solid electrolyte sheet 22 and the electrode under test 21 are pressed into sheet shape in the mold sleeve 11 and housed in the mold sleeve 11. The second solid electrolyte sheet 23 is pressed into sheet shape in the insulating sleeve 14 and housed in the insulating sleeve 14. The first lithium alloy electrode 24 is housed in the cavity formed by the insulating pad 13 surrounding the protrusion. The second lithium alloy electrode 25 is housed in the insulating sleeve 14.

[0044] This disclosure, by introducing an insulating sleeve into the mold sleeve, can avoid short circuits in the system under test, thereby improving the consistency and accuracy of the solid-state battery cell electrode ion conductivity test results.

[0045] In some embodiments, the press assembly 3 may include a first hydraulic plate and a second hydraulic plate disposed opposite to each other, the first hydraulic plate and the second hydraulic plate being used to apply pressure to both ends of the mold assembly 1. The press assembly 3 may also include components such as a pressure gauge (not shown).

[0046] In some embodiments, the projections of the first lithium alloy electrode 24, the second solid electrolyte sheet 23, and the second lithium alloy electrode 25 overlap.

[0047] In some embodiments, the protrusion on the first electrode post 12 is cylindrical, and the insulating pad 13 is annular.

[0048] In some embodiments, the mold sleeve 11 is cylindrical, and the opening extends along the axial direction of the mold sleeve 11.

[0049] In some embodiments, the insulating sleeve 14 is cylindrical, and the opening extends along the axial direction of the insulating sleeve 14.

[0050] In some embodiments, the outer diameter of the insulating sleeve 14 is equal to the inner diameter of the mold sleeve 11.

[0051] In some embodiments, the insulating sleeve 14 may be made of insulating plastic, such as polyetheretherketone, polyurethane, polymethyl methacrylate, etc.

[0052] In some embodiments, the mold sleeve 11 can be made of insulating plastic, such as polyetheretherketone, polyurethane, polymethyl methacrylate, etc.

[0053] In some embodiments, the first lithium alloy electrode 24 may be a lithium indium alloy electrode.

[0054] In some embodiments, the second lithium alloy electrode 25 may be a lithium indium alloy electrode.

[0055] In some embodiments, the ionic conductivity of the first solid electrolyte sheet 22 at 25°C can be greater than or equal to 1×10⁻⁶. -3 S / cm, and the electronic conductivity at 25℃ can be less than or equal to 1×10⁻⁶. -9 S / cm.

[0056] In some embodiments, the ionic conductivity of the second solid electrolyte sheet 23 at 25°C can be greater than or equal to 1×10⁻⁶. -3 S / cm, and the electronic conductivity at 25℃ can be less than or equal to 1×10⁻⁶. -9 S / cm.

[0057] In some embodiments, the first solid electrolyte sheet 22 and the second solid electrolyte sheet 23 may each independently include one or more of the following: sulfide solid electrolyte material, halide solid electrolyte material, and oxide solid electrolyte material.

[0058] In some embodiments, the sulfide solid electrolyte material may include one or more of the following: silver sulfide-germanium sulfide solid electrolyte material, Li2S-GeS2 type sulfide solid electrolyte material, Li2S-P2S5 type sulfide solid electrolyte material, Li2S-SiS2 type sulfide solid electrolyte material, and Li2S-MS2-P2S5 type sulfide solid electrolyte material, and M may include one or more elements selected from Si, Ge, Sn, and Al.

[0059] Optionally, the sulfide solid electrolyte material of the silver-germanium sulfide type may include Li 6±s P 1-j A j S 5±s- t B t X 1±s The material has the following properties: 0≤j<1, 0≤t<1, 0≤s<1, A includes one or more elements from Ge, Si, Sn and Sb, B includes one or more elements from O, Se and Te, and X includes one or more elements from Cl, Br, I and F.

[0060] As an example, sulfide solid electrolyte materials may include Li6PS5Cl, Li6PS5Br, Li 10 GeP2S 12 Li3PS4, Li7P3S 11 One or more of them.

[0061] In some embodiments, the halide solid electrolyte material may include one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, and Li3InBr6.

[0062] In some embodiments, the oxide solid electrolyte material may include one or more of the following: perovskite structure oxide solid electrolyte material, garnet structure oxide solid electrolyte material, NASICON structure oxide solid electrolyte material, and LISICON structure oxide solid electrolyte material.

[0063] In some embodiments, the electrode to be tested 21 can be a positive electrode or a negative electrode.

[0064] In some embodiments, the electrode under test 21 is a positive electrode, which may include a positive electrode active material, a solid electrolyte material, and a positive electrode conductive agent.

[0065] In some embodiments, the solid electrolyte material in the positive electrode may be one or more of sulfide solid electrolyte materials, halide solid electrolyte materials, and oxide solid electrolyte materials, including but not limited to. The types of sulfide solid electrolyte materials, halide solid electrolyte materials, and oxide solid electrolyte materials can be found above and will not be repeated here.

[0066] In some embodiments, the positive electrode conductive agent may be one or more of the following, including but not limited to superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0067] In some embodiments, the positive electrode active material may include one or more of lithium transition metal oxides and their modified forms, lithium-containing phosphates and their modified forms, lithium manganese oxide, lithium titanate, lithium niobate, sulfur, selenium, and tellurium. Optionally, examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium-rich manganese-based materials. Optionally, examples of lithium-containing phosphates may include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0068] In some embodiments, the positive electrode active material may include materials with the general formula Li a Ni b Co c M d O e A f One or more of lithium transition metal oxides and their modified materials. 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M includes one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A includes one or more of N, F, S and Cl.

[0069] In some embodiments, as an example, the positive electrode active material may include, but is not limited to, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (abbreviated as NCM523), LiNi 0.5 Co 0.25 Mn0.25 O2 (abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (abbreviated as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (abbreviated as NCM811), LiNi 0.83 Mn 0.08 Co 0.07 O2 (abbreviated as Ni83), LiNi 0.90 Mn 0.05 Co 0.05 O2 (abbreviated as Ni90), LiNi 0.94 Mn 0.03 Co 0.03 O2 (abbreviated as Ni94), LiNi 0.96 Co 0.02 Mn 0.02 O2 (abbreviated as Ni96), LiNi 0.80 Co 0.15 Al 0.05 One or more of O2, LiFePO4, LiMnPO4 and their respective modified materials.

[0070] The modified materials for the above-mentioned positive electrode active materials can be doped and / or surface coated.

[0071] During the charging and discharging process, solid-state battery cells undergo Li insertion / extraction and consumption, resulting in varying Li molar content at different discharge states. In this disclosure, the Li molar content listed for positive electrode active materials represents the initial state of the material, i.e., the state before material addition. As the positive electrode active material is applied to a solid-state battery cell, the Li molar content changes after charge-discharge cycles. Similarly, the O molar content listed for positive electrode active materials in this disclosure is only a theoretical value; lattice oxygen release causes changes in the O molar content, leading to fluctuations in the actual O molar content.

[0072] In some embodiments, the positive electrode may also include a positive electrode binder.

[0073] Optionally, the positive electrode binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene-propylene terpolymer, ethylene-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), styrene-butadiene rubber (SBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0074] In some embodiments, the electrode under test 21 is a negative electrode, which may include a negative electrode active material, a solid electrolyte material, and a negative electrode conductive agent.

[0075] In some embodiments, the solid electrolyte material in the negative electrode may be one or more of sulfide solid electrolyte materials, halide solid electrolyte materials, and oxide solid electrolyte materials, including but not limited to. The types of sulfide solid electrolyte materials, halide solid electrolyte materials, and oxide solid electrolyte materials can be found above and will not be repeated here.

[0076] In some embodiments, the negative electrode conductive agent may be one or more of the following, including but not limited to superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0077] In some embodiments, the negative electrode active material may include, but is not limited to, one or more of natural graphite, artificial graphite, mesophase microcarbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides. Optionally, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Optionally, the tin-based material may include, but is not limited to, one or more of elemental tin, tin oxides, and tin alloys. Optionally, the metal oxide includes one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5, and Bi2O5.

[0078] In some embodiments, the negative electrode may further include a negative electrode binder.

[0079] Optionally, the negative electrode binder may be one or more of the following: styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), carboxymethyl chitosan (CMCS), methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, acrylate rubber, and sodium carboxymethyl cellulose (CMC).

[0080] This disclosure also provides a method for detecting the ionic conductivity of a solid-state battery cell electrode using the apparatus disclosed herein.

[0081] The detection method includes the following steps: An insulating pad 13 is arranged around the protrusion of the first electrode post 12 and assembled together to obtain a first electrode post 12 equipped with the insulating pad 13; then, the first electrode post 12 equipped with the insulating pad 13 is inserted into the first opening of the mold sleeve 11; first solid electrolyte material powder is placed in the mold sleeve 11 through the second opening of the mold sleeve 11; a movable electrode post is inserted into the mold sleeve 11 through the second opening of the mold sleeve 11, and the first solid electrolyte material powder is pressed into a first solid electrolyte sheet 22 in the mold sleeve 11; the movable electrode post is removed; the electrode powder to be tested is placed in the mold sleeve 11 through the second opening of the mold sleeve 11; the movable electrode post is inserted into the mold sleeve 11 through the second opening of the mold sleeve 11, and the electrode powder to be tested is pressed into a test electrode 21 in the mold sleeve 11; the movable electrode post is removed; and an insulating sleeve 14 is inserted into the mold sleeve 11 through the second opening of the mold sleeve 11. The second opening of 11 is inserted into the mold sleeve 11; the second solid electrolyte material powder is placed in the insulating sleeve 14 through the opening of the insulating sleeve 14, the second electrode post 15 is inserted into the insulating sleeve 14 through the opening of the insulating sleeve 14, and the second solid electrolyte material powder is pressed into the second solid electrolyte sheet 23 in the insulating sleeve 14; the first electrode post 12 and the second electrode post 15 equipped with the insulating pad 13 are taken out, and the first electrode and the second electrode are placed outside the first solid electrolyte sheet 22 and the second solid electrolyte sheet 23 respectively, and then the first electrode post 12 and the second electrode post 15 equipped with the insulating pad 13 are installed to assemble the mold assembly 1; the mold assembly 1 is pressed by the press assembly 3 and the pressure is maintained continuously, and the mold assembly 1 is electrically connected to the electrochemical workstation to form a detection circuit, and the ionic conductivity of the electrode 21 to be tested is tested by the electrochemical impedance spectroscopy (EIS) method using the electrochemical workstation.

[0082] The movable electrode post is used to insert into the second opening of the mold sleeve 11 and can be easily removed after the powder, such as the first solid electrolyte material powder or the electrode powder to be tested, which is loaded into the mold sleeve 11 is pressed into a sheet.

[0083] The test electrode powder refers to all substances used to form the test electrode 21.

[0084] Example

[0085] The following embodiments describe the disclosure of this disclosure in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0086] Example 1

[0087] Ion conductivity test

[0088] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) are mixed at a mass ratio of 85:14:1 for 10 min to obtain positive electrode powder 1#.

[0089] The insulating pad 13 is arranged around the protrusion of the first electrode post 12 and assembled together to obtain the first electrode post 12 equipped with the insulating pad 13. Then, the first electrode post 12 equipped with the insulating pad 13 is inserted into the first opening of the mold sleeve 11.

[0090] A certain mass of the first solid electrolyte material Li6PS5Cl powder is weighed and placed in the mold sleeve 11 through the second opening of the mold sleeve 11. The movable electrode post is inserted into the mold sleeve 11 through the second opening of the mold sleeve 11. The first solid electrolyte material Li6PS5Cl powder is gently rotated and flattened by the movable electrode post and then pressed into the first solid electrolyte sheet 22 by a pressure of 300 MPa.

[0091] Carefully remove the movable electrode post, weigh a certain mass of positive electrode powder 1# and place it in the mold sleeve 11 through the second opening of the mold sleeve 11. Insert the movable electrode post into the mold sleeve 11 through the second opening of the mold sleeve 11. Use the movable electrode post to gently flatten the positive electrode powder 1# and press it into the electrode to be tested 21 under a pressure of 300 MPa.

[0092] Remove the movable electrode post and insert the insulating sleeve 14 into the mold sleeve 11 through the second opening of the mold sleeve 11.

[0093] A certain mass of the second solid electrolyte material Li6PS5Cl powder is weighed and placed in the insulating sleeve 14 through the opening of the insulating sleeve 14. The second electrode post 15 is inserted into the insulating sleeve 14 through the opening of the insulating sleeve 14. The second solid electrolyte material Li6PS5Cl powder is gently leveled by the second electrode post 15 and then pressed into a second solid electrolyte sheet 23 by a pressure of 300 MPa.

[0094] Remove the first electrode post 12 and the second electrode post 15 equipped with insulating pads 13, place 10μm thick lithium indium alloy sheets outside the first solid electrolyte sheet 22 and the second solid electrolyte sheet 23 respectively, and then insert the first electrode post 12 and the second electrode post 15 equipped with insulating pads 13 to assemble the mold assembly 1.

[0095] The mold assembly 1 is placed between the first hydraulic plate and the second hydraulic plate of the press assembly, and then a pressure of 350 MPa is applied to the mold assembly 1 for pressing and the pressure is maintained.

[0096] The mold assembly 1 is electrically connected to the electrochemical workstation to form a detection circuit. The ionic conductivity of the positive electrode powder 1# is tested by electrochemical impedance spectroscopy (EIS) using the electrochemical workstation.

[0097] The total impedance R1 of the electrode under test 21, the first solid electrolyte sheet 22, and the second solid electrolyte sheet 23 was measured using electrochemical impedance spectroscopy (EIS) on an electrochemical workstation. The total impedance R2 of the first solid electrolyte sheet 22 and the second solid electrolyte sheet 23 was also measured using EIS. R1 - R2 represents the impedance of the electrode under test 21. The total thickness of the electrode under test 21, the first solid electrolyte sheet 22, and the second solid electrolyte sheet 23 is D1, and the total thickness of the first solid electrolyte sheet 22 and the second solid electrolyte sheet 23 is D2. D1 - D2 represents the thickness of the electrode under test 21. The EIS test was conducted at 25°C, with a bias voltage of 10mV and a frequency ranging from 10MHz to 0.1×10⁻⁶. -3 Hz.

[0098] The ionic conductivity σ of cathode powder #1 is calculated using the formula σ=(D1-D2) / [(R1-R2)×S]. S is the cross-sectional area.

[0099] Electron conductivity test

[0100] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) are mixed at a mass ratio of 85:14:1 for 10 min to obtain positive electrode powder 1#.

[0101] like Figure 5 As shown, the lower electrode post 111 is inserted into the first opening of the mold sleeve 11. A certain mass of positive electrode powder 1# is weighed and placed in the mold sleeve 11 through the second opening. The upper electrode post 112 is inserted into the mold sleeve 11 through the second opening. The positive electrode powder 1# is gently leveled with the upper electrode post 112 and then pressed with a pressure of 300 MPa.

[0102] The mold is placed between the first and second hydraulic plates of the press assembly, and then a pressure of 350 MPa is applied to the mold for pressing and the pressure is maintained.

[0103] The mold is electrically connected to the electrochemical workstation to form a detection circuit. The electronic conductivity of the positive electrode powder 1# is tested by electrochemical impedance spectroscopy (EIS) using the electrochemical workstation.

[0104] The total impedance R' of the electrode under test was measured using electrochemical impedance spectroscopy (EIS) on an electrochemical workstation. The total thickness of the electrode under test was D'. The EIS test temperature was 25℃, the bias voltage was set to 10mV, and the frequency was from 10MHz to 0.1×10⁻⁶. -3 Hz.

[0105] The electronic conductivity σ' of cathode powder #1 is calculated using the formula σ'=D' / (R'×S). S is the cross-sectional area.

[0106] Example 2

[0107] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were mixed at a mass ratio of 85:13.5:1.5 for 10 min to obtain positive electrode powder #2.

[0108] The testing methods for the ionic conductivity and electronic conductivity of cathode powder #2 are the same as those for cathode powder #1.

[0109] Example 3

[0110] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were mixed at a mass ratio of 85:13:2 for 10 min to obtain positive electrode powder #3.

[0111] The testing methods for the ionic conductivity and electronic conductivity of cathode powder #3 are the same as those for cathode powder #1.

[0112] Comparative Example 1

[0113] Ion conductivity test

[0114] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) are mixed at a mass ratio of 85:14:1 for 10 min to obtain positive electrode powder 1#.

[0115] like Figure 5 As shown, the lower electrode post 111 is inserted into the first opening of the mold sleeve 11. A certain mass of the first solid electrolyte material Li6PS5Cl powder is weighed and placed in the mold sleeve 11 through the second opening. The upper electrode post 112 is inserted into the mold sleeve 11 through the second opening. The first solid electrolyte material Li6PS5Cl powder is gently leveled by the upper electrode post 112 and then pressed into a first solid electrolyte sheet by a pressure of 300 MPa.

[0116] Carefully remove the upper electrode post 112, weigh a certain mass of positive electrode powder 1# and place it in the mold sleeve 11 through the second opening of the mold sleeve 11. Insert the upper electrode post 112 into the mold sleeve 11 through the second opening of the mold sleeve 11. Use the upper electrode post 112 to gently flatten the positive electrode powder 1# and press it into the electrode to be tested under a pressure of 300 MPa.

[0117] Take out the upper electrode post 112, weigh a certain mass of the second solid electrolyte material Li6PS5Cl powder and place it in the mold sleeve 11 through the second opening of the mold sleeve 11. Insert the upper electrode post 112 into the mold sleeve 11 through the second opening of the mold sleeve 11. Use the upper electrode post 112 to gently flatten the second solid electrolyte material Li6PS5Cl powder and then press it into a second solid electrolyte sheet with a pressure of 300 MPa.

[0118] Remove the lower electrode post 111 and the upper electrode post 112, place 10μm thick lithium indium alloy sheets outside the first solid electrolyte sheet and the second solid electrolyte sheet respectively, and then insert the lower electrode post 111 and the upper electrode post 112 to assemble the mold assembly.

[0119] The mold assembly is placed between the first and second hydraulic plates of the press assembly, and then a pressure of 350 MPa is applied to the mold assembly for pressing and the pressure is maintained.

[0120] The mold assembly is electrically connected to the electrochemical workstation to form a detection circuit. The ionic conductivity of the positive electrode powder 1# is tested by electrochemical impedance spectroscopy (EIS) using the electrochemical workstation.

[0121] The total impedance R1 of the electrode under test, the first solid electrolyte sheet, and the second solid electrolyte sheet was measured using electrochemical impedance spectroscopy (EIS) on an electrochemical workstation. The total impedance R2 of the first and second solid electrolyte sheets was also measured using EIS. R1 - R2 represents the impedance of the electrode under test. The total thickness of the electrode under test, the first solid electrolyte sheet, and the second solid electrolyte sheet is D1, and the total thickness of the first and second solid electrolyte sheets is D2. D1 - D2 represents the thickness of the electrode under test. The EIS measurement was performed at 25°C, with a bias voltage of 10mV and a frequency ranging from 10MHz to 0.1×10⁻⁶. -3 Hz.

[0122] The ionic conductivity σ of cathode powder #1 is calculated using the formula σ=(D1-D2) / [(R1-R2)×S]. S is the cross-sectional area.

[0123] Electron conductivity test

[0124] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) are mixed at a mass ratio of 85:14:1 for 10 min to obtain positive electrode powder 1#.

[0125] like Figure 5 As shown, the lower electrode post 111 is inserted into the first opening of the mold sleeve 11. A certain mass of positive electrode powder 1# is weighed and placed in the mold sleeve 11 through the second opening. The upper electrode post 112 is inserted into the mold sleeve 11 through the second opening. The positive electrode powder 1# is gently leveled with the upper electrode post 112 and then pressed with a pressure of 300 MPa.

[0126] The mold is placed between the first and second hydraulic plates of the press assembly, and then a pressure of 350 MPa is applied to the mold for pressing and the pressure is maintained.

[0127] The mold is electrically connected to the electrochemical workstation to form a detection circuit. The electronic conductivity of the positive electrode powder 1# is tested by electrochemical impedance spectroscopy (EIS) using the electrochemical workstation.

[0128] The total impedance R' of the electrode under test was measured using electrochemical impedance spectroscopy (EIS) on an electrochemical workstation. The total thickness of the electrode under test was D'. The EIS test temperature was 25℃, the bias voltage was set to 10mV, and the frequency was from 10MHz to 0.1×10⁻⁶. -3 Hz.

[0129] The electronic conductivity σ' of cathode powder #1 is calculated using the formula σ'=D' / (R'×S). S is the cross-sectional area.

[0130] Table 1

[0131]

[0132] As can be seen from the above test results, the detection device provided in this disclosure can improve the consistency and accuracy of ionic conductivity test results.

[0133] It should be noted that this disclosure is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same essential structure and achieving the same effect as the technical concept within the scope of this disclosure are included in the technical scope of this disclosure. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, are also included in the scope of this disclosure without departing from the spirit of this disclosure.

Claims

1. A device for detecting ion conductivity of a solid-state battery electrode, characterized in that, the device comprises a mold assembly, an electrochemical workstation and a press assembly, the press assembly is used to apply pressure to the mold assembly, the electrochemical workstation is electrically connected with the mold assembly and constitutes a detection loop; the mold assembly comprises a mold structure and a solid-state battery electrode assembly to be detected, the mold structure is used to accommodate the solid-state battery electrode assembly to be detected; the mold structure comprises: a mold sleeve with a first opening and a second opening arranged oppositely; a first electrode column for insertion into the first opening, one end of the first electrode column towards the second opening is provided with a protrusion; an insulating gasket arranged on the first electrode column and surrounding the protrusion; an insulating sleeve for insertion into the mold sleeve through the second opening; a second electrode column for insertion into the insulating sleeve, the solid-state battery electrode assembly to be detected comprises a test electrode, a first solid-state electrolyte sheet, a second solid-state electrolyte sheet, a first lithium alloy electrode and a second lithium alloy electrode, the test electrode is located between the first solid-state electrolyte sheet and the second solid-state electrolyte sheet, the first lithium alloy electrode is located between the first solid-state electrolyte sheet and the first electrode column, and the second lithium alloy electrode is located between the second solid-state electrolyte sheet and the second electrode column; the first solid-state electrolyte sheet and the test electrode are pressed into a sheet shape in the mold sleeve and accommodated in the mold sleeve, the second solid-state electrolyte sheet is pressed into a sheet shape in the insulating sleeve and accommodated in the insulating sleeve, the first lithium alloy electrode is accommodated in the cavity formed by the insulating gasket surrounding the protrusion, and the second lithium alloy electrode is accommodated in the insulating sleeve.

2. The apparatus of claim 1, wherein, The projections of the first lithium alloy electrode, the second solid-state electrolyte sheet and the second lithium alloy electrode coincide. 3.The device according to any one of claims 1-2, characterized in that, the first solid-state electrolyte sheet has an ionic conductivity of 1 x 10 -3 S / cm at 25 °C, an electronic conductivity of less than or equal to 1 x 10 -9 S / cm at 25 °C; and / or, the second solid-state electrolyte sheet has an ionic conductivity of 1 x 10 -3 S / cm at 25 °C and an electronic conductivity of 1 x 10 -9 S / cm at 25 °C.

4. The device according to any of claims 1-3, characterized in that the first lithium alloy electrode is a lithium-indium alloy electrode.

5. The device according to any of claims 1-4, characterized in that the second lithium alloy electrode is a lithium-indium alloy electrode.

6. The device of any one of claims 1-5, wherein, the first solid-state electrolyte sheet and the second solid-state electrolyte sheet each independently comprise one or more of sulfide solid-state electrolyte material, halide solid-state electrolyte material and oxide solid-state electrolyte material.

7. The device of any one of claims 1-6, wherein, the test electrode is a positive electrode, and the positive electrode comprises positive electrode active material, solid-state electrolyte material and positive electrode conductive agent.

8. The device of any one of claims 1-7, wherein, the test electrode is a negative electrode, and the negative electrode comprises negative electrode active material, solid-state electrolyte material and negative electrode conductive agent.

9. The device of any one of claims 1-8, wherein, the press assembly comprises a first hydraulic plate and a second hydraulic plate arranged oppositely, and the first hydraulic plate and the second hydraulic plate are used to apply pressure to both ends of the mold assembly. 10.A method for detecting ion conductivity of a solid-state battery electrode by using the device according to any one of claims 1-9, comprising the following steps: surrounding the insulating gasket around the protrusion arranged on the first electrode column and assembling them together to obtain the first electrode column assembled with the insulating gasket, and then inserting the first electrode column assembled with the insulating gasket into the first opening of the mold sleeve; placing a first solid-state electrolyte material powder into the mold sleeve through the second opening of the mold sleeve, inserting a movable electrode column into the mold sleeve through the second opening of the mold sleeve and pressing the first solid-state electrolyte material powder into a first solid-state electrolyte sheet in the mold sleeve; removing the movable electrode column, placing a to-be-tested electrode powder into the mold sleeve through the second opening of the mold sleeve, inserting the movable electrode column into the mold sleeve through the second opening of the mold sleeve and pressing the to-be-tested electrode powder into a to-be-tested electrode in the mold sleeve; removing the movable electrode column, inserting an insulating sleeve into the mold sleeve through the second opening of the mold sleeve; placing a second solid-state electrolyte material powder into the insulating sleeve through the opening of the insulating sleeve, inserting a second electrode column into the insulating sleeve through the opening of the insulating sleeve and pressing the second solid-state electrolyte material powder into a second solid-state electrolyte sheet in the insulating sleeve; removing the first electrode column and the second electrode column equipped with insulating spacers, placing a first lithium alloy electrode and a second lithium alloy electrode outside the first solid-state electrolyte sheet and the second solid-state electrolyte sheet respectively, and then assembling the first electrode column and the second electrode column equipped with insulating spacers to obtain a mold assembly; applying pressure to the mold assembly by using a press assembly and maintaining the pressure, electrically connecting the mold assembly with an electrochemical workstation to form a detection loop, and testing the ionic conductivity of the to-be-tested electrode by using the electrochemical workstation through electrochemical impedance spectroscopy (EIS).

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