Solid state electrolytes and applications thereof

Abstract

The application discloses a kind of solid electrolyte and its application, the solid electrolyte is respectively arranged first polymer electrolyte layer and second polymer electrolyte layer on the two sides of sulfide electrolyte layer, the first polymer electrolyte layer includes sulfonic acid lactone base polymer, the monomer of the sulfonic acid lactone base polymer includes the sulfonic acid lactone of unsaturation ≥1, it is a kind of oxidation-resistant polymer electrolyte layer;The second polymer electrolyte layer includes carbonic acid vinylidene ester base polymer, it is a kind of anti-reduction polymer electrolyte layer.The solid electrolyte has excellent ionic conductivity, electronic conductivity, electrochemical window and mechanical strength.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and relates to an electrolyte, in particular to a solid-state electrolyte and application thereof. BACKGROUND

[0002] As a kind of secondary battery, lithium ion battery mainly relies on the movement of lithium ion between positive electrode and negative electrode to realize charge and discharge work. Lithium ion battery has been widely used due to its characteristics such as high energy density, no memory effect, high working voltage and environmental friendliness.

[0003] At present, the electrolyte of most lithium ion batteries is liquid, and the liquid battery formed by the liquid electrolyte has defects such as continuous growth of SEI film, transition metal dissolution, positive electrode material oxygen evolution, electrolyte oxidation, negative electrode lithium precipitation, high temperature failure and volume expansion.

[0004] The above-mentioned shortcomings are related to the low chemical stability, electrochemical stability and thermal stability of the electrolyte. If the shortcomings of the liquid electrolyte lithium ion battery can be overcome, the electrochemical performance and safety of the battery will be significantly improved. In order to improve safety, flame retardant additives, ionic liquids and the like have been widely researched and developed in the aspect of liquid electrolyte, but they cannot solve the above-mentioned shortcomings at the same time. Therefore, non-flammable solid-state electrolyte battery has become the research endpoint of people, and how to provide a full solid-state electrolyte has become a technical problem to be solved at present. SUMMARY

[0005] In view of the problems in the prior art, the application provides a solid-state electrolyte and application thereof. The solid-state electrolyte has a heterogeneous structure, and has excellent mechanical properties, high ionic conductivity, electronic conductivity and a wide electrochemical window.

[0006] To achieve the above purpose, the application adopts the following technical solutions:

[0007] In a first aspect, the application provides a solid-state electrolyte, which comprises a first polymer electrolyte layer, a sulfide electrolyte layer and a second polymer electrolyte layer arranged in layers.

[0008] The first polymer electrolyte layer comprises a sulfonic lactone-based polymer; the monomer of the sulfonic lactone-based polymer comprises a sulfonic lactone with unsaturation degree ≥1.

[0009] The second polymer electrolyte layer comprises a vinylene carbonate-based polymer.

[0010] The solid-state electrolyte provided by the application comprises a first polymer electrolyte layer, a sulfide electrolyte layer and a second polymer electrolyte layer arranged in a stack. The electrochemical window of the sulfide electrolyte material is narrow. By arranging the first polymer electrolyte layer comprising a sulfolactone-based polymer on the positive electrode side of the sulfide electrolyte layer, the solid-state electrolyte can resist oxidation. By arranging the second polymer electrolyte layer comprising a vinylene carbonate-based polymer on the negative electrode side of the sulfide electrolyte layer, the solid-state electrolyte can resist reduction.

[0011] The solid-state electrolyte provided by the application not only has excellent tensile strength, but also has excellent ionic conductivity and electronic conductivity, and has a wider electrochemical window.

[0012] Preferably, the raw materials for preparing the sulfolactone-based polymer comprise a first sulfur-containing polymer monomer, a second sulfur-containing polymer monomer, a polymerization additive monomer and an initiator.

[0013] The first sulfur-containing polymer monomer comprises any one or a combination of at least two of:

[0014] 、 、 、 、 or .

[0015] The second sulfur-containing polymer monomer comprises any one or a combination of at least two of:

[0016] 、 or .

[0017] Preferably, the polymeric additive monomer comprises any one or a combination of at least two of polyethylene glycol monomethyl ether methacrylate (PEGMEMA), poly(ethylene glycol) diacrylate, methoxypolyethylene glycol acrylate, trimethylpropane ethoxylate triacrylate, propoxylated trimethylolpropane triacrylate, or 2,3-epoxypropyl acrylate; exemplary, but non-limiting combinations include a combination of PEGMEMA and poly(ethylene glycol) diacrylate, a combination of methoxypolyethylene glycol acrylate and trimethylpropane ethoxylate triacrylate, a combination of propoxylated trimethylolpropane triacrylate and 2,3-epoxypropyl acrylate, a combination of PEGMEMA, poly(ethylene glycol) diacrylate, and methoxypolyethylene glycol acrylate, a combination of trimethylpropane ethoxylate triacrylate, propoxylated trimethylolpropane triacrylate, and 2,3-epoxypropyl acrylate, or a combination of PEGMEMA, poly(ethylene glycol) diacrylate, methoxypolyethylene glycol acrylate, trimethylpropane ethoxylate triacrylate, propoxylated trimethylolpropane triacrylate, and 2,3-epoxypropyl acrylate.

[0018] Preferably, the initiator comprises any one or a combination of at least two of azobisisobutyronitrile, dibenzoyl peroxide, sodium persulfate, or potassium persulfate, preferably azobisisobutyronitrile.

[0019] Preferably, the raw materials for preparing the sulfolane-based polymer comprise, in mole percentage:

[0020] the first sulfur-containing polymer monomer 93 mol% to 95 mol%;

[0021] the second sulfur-containing polymer monomer 2.5 mol% to 3.5 mol%;

[0022] the polymeric additive monomer 2.2 mol% to 2.7 mol%;

[0023] the initiator 0.3 mol% to 0.8 mol%.

[0024] The raw materials for preparing the sulfolane-based polymer of the present application comprise, in mole percentage, the first sulfur-containing polymer monomer 93 mol% to 95 mol%, for example, it can be 93 mol%, 93.5 mol%, 94 mol%, 94.5 mol%, or 95 mol%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0025] The mole percentage of the second sulfur-containing polymer monomer in the raw material for preparing the lactone-based polymer is 2.5 mol% to 3.5 mol%, for example, can be 2.5 mol%, 2.7 mol%, 2.8 mol%, 3 mol%, 3.2 mol%, or 3.5 mol%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0026] The mole percentage of the polymer additive monomer in the raw material for preparing the lactone-based polymer is 2.2 mol% to 2.7 mol%, for example, can be 2.2 mol%, 2.3 mol%, 2.4 mol%, 2.5 mol%, 2.6 mol%, or 2.7 mol%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0027] The mole percentage of the initiator in the raw material for preparing the lactone-based polymer is 0.3 mol% to 0.8 mol%, for example, can be 0.3 mol%, 0.4 mol%, 0.5 mol%, 0.6 mol%, 0.7 mol%, or 0.8 mol%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0028] For example, the method for preparing the lactone-based polymer comprises the following steps:

[0029] The first sulfur-containing polymer monomer, the second sulfur-containing polymer monomer, the polymer additive monomer, the initiator, and the solvent are mixed according to the formula to obtain a mixed solution with a solid content of 20% to 50%; the reaction is carried out at 55°C to 65°C for 24 h to 36 h to obtain a polymer material; and the obtained polymer material is crushed and vacuum dried to obtain the lactone-based polymer.

[0030] Preferably, the solid content of the mixed solution is 20% to 50%, for example, can be 20%, 25%, 30%, 35%, 40%, 45%, or 50%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0031] Preferably, the temperature of the reaction is 55°C to 65°C, for example, can be 55°C, 56°C, 58°C, 60°C, 62°C, 64°C, or 65°C, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0032] Preferably, the reaction time is 24 h to 36 h, for example, can be 24 h, 25 h, 27 h, 28 h, 30 h, 32 h, 35 h, or 36 h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0033] Preferably, the reaction is accompanied by condensation reflux and stirring.

[0034] Preferably, the temperature of the vacuum drying is 70-80°C, for example, it can be 70°C, 72°C, 75°C, 76°C, 78°C or 80°C, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0035] Preferably, the time of the vacuum drying is 24h or more, for example, it can be 24h, 25h, 27h, 28h or 30h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0036] The present application removes the unreacted reaction raw materials by vacuum drying, preventing the residual reaction raw materials from affecting the performance of the obtained solid-state electrolyte.

[0037] Preferably, after the vacuum drying, it further includes deionized water washing and dimethyl carbonate cleaning, and the washing endpoint is that there is no any one of the reaction raw materials in the washing liquid.

[0038] For example, the preparation method of the first polymer electrolyte layer of the present application includes the following steps:

[0039] Mix the sulfolane-based polymer, butanedinitrile and organic solvent according to the mass ratio (45-50):(1-3):(49-52) to obtain a first electrolyte mixture; mix the lithium salt with the first electrolyte mixture to obtain a first electrolyte slurry with a lithium salt concentration of 1.2-1.8 mol / L; after the first electrolyte slurry is coated according to the required thickness, remove the organic solvent by vacuum drying to obtain the first polymer electrolyte layer.

[0040] Preferably, the lithium salt includes any one or a combination of at least two of lithium bis(trifluoromethylsulfonyl)imide, lithium hexafluorophosphate (LIPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethylsulfonate (LiCF3SO3), lithium tetrafluoro oxalate phosphate (LiTFOP), lithium trioxalate phosphate (LiTOP), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium bis(perfluoroethylsulfonyl)imide (LiFSI), lithium (trifluoromethylsulfonyl)(n-perfluorobutylsulfonyl)imide (LiFNTFSI), lithium (fluorosulfonyl)(n-perfluorobutylsulfonyl)imide (LiFNFSI) or lithium bis(oxalate)borate (LiBOB).

[0041] Preferably, the organic solvent includes but is not limited to dimethyl sulfoxide.

[0042] Preferably, the temperature of the vacuum drying is 80 °C to 100 °C, such as can be 80 °C, 85 °C, 90 °C, 95 °C, or 100 °C, but is not limited to the recited values, other unrecited values within the range of values are equally applicable.

[0043] Preferably, the time of the vacuum drying is > 24 h, such as can be 24 h, 25 h, 27 h, 28 h, or 30 h, but is not limited to the recited values, other unrecited values within the range of values are equally applicable.

[0044] Preferably, the raw materials for the preparation of the vinylene carbonate-based polymer include vinylene carbonate, ethylene glycol diacrylate, a polymerization additive monomer, and an initiator.

[0045] Preferably, the polymerization additive monomer includes any one or a combination of at least two of polyethylene glycol monomethyl ether methacrylate (PEGMEMA), poly(ethylene glycol) diacrylate, methoxypolyethylene glycol acrylate, trimethylpropane ethoxylate triacrylate, propoxylated trimethylolpropane triacrylate, or 2,3-epoxypropyl acrylate; typical but non-limiting combinations include a combination of PEGMEMA and poly(ethylene glycol) diacrylate, a combination of methoxypolyethylene glycol acrylate and trimethylpropane ethoxylate triacrylate, a combination of propoxylated trimethylolpropane triacrylate and 2,3-epoxypropyl acrylate, a combination of PEGMEMA, poly(ethylene glycol) diacrylate, and methoxypolyethylene glycol acrylate, a combination of trimethylpropane ethoxylate triacrylate, propoxylated trimethylolpropane triacrylate, and 2,3-epoxypropyl acrylate, or a combination of PEGMEMA, poly(ethylene glycol) diacrylate, methoxypolyethylene glycol acrylate, trimethylpropane ethoxylate triacrylate, propoxylated trimethylolpropane triacrylate, and 2,3-epoxypropyl acrylate.

[0046] Preferably, the initiator includes any one or a combination of at least two of azobisisobutyronitrile, dibenzoyl peroxide, sodium persulfate, or potassium persulfate, preferably azobisisobutyronitrile.

[0047] Preferably, the raw materials for the preparation of the vinylene carbonate-based polymer include, in mole percent:

[0048] vinylene carbonate 93.5 mol% to 94.6 mol%;

[0049] ethylene glycol diacrylate 2.8 mol% to 3.2 mol%;

[0050] polymerization additive monomer 2.4 mol% to 2.7 mol%;

[0051] initiator 0.2 mol% to 0.6 mol%.

[0052] The mole percentage of vinylene carbonate in the raw material for preparing the vinylene carbonate-based polymer is 93.5 mol% to 94.6 mol%, for example, can be 93.5 mol%, 93.6 mol%, 93.8 mol%, 94 mol%, 94.2 mol%, 94.5 mol% or 94.6 mol%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0053] The mole percentage of ethylene glycol diacrylate in the raw material for preparing the vinylene carbonate-based polymer is 2.8 mol% to 3.2 mol%, for example, can be 2.8 mol%, 2.9 mol%, 3 mol%, 3.1 mol% or 3.2 mol%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0054] The mole percentage of the polymer additive monomer in the raw material for preparing the vinylene carbonate-based polymer is 2.4 mol% to 2.7 mol%, for example, can be 2.4 mol%, 2.5 mol%, 2.6 mol% or 2.7 mol%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0055] The mole percentage of the initiator in the raw material for preparing the vinylene carbonate-based polymer is 0.2 mol% to 0.6 mol%, for example, can be 0.2 mol%, 0.3 mol%, 0.4 mol%, 0.5 mol% or 0.6 mol%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0056] For example, the preparation method of the vinylene carbonate-based polymer of the present application comprises the following steps:

[0057] The vinylene carbonate, ethylene glycol diacrylate, polymer additive monomer, initiator and cyclohexane solvent are mixed according to the formula amount to obtain a mixed solution with a solid content of 20% to 50%; the mixed solution is reacted at 55°C to 65°C for 24h to 36h to obtain a polymer material; and the obtained polymer material is crushed and vacuum dried to obtain the vinylene carbonate-based polymer.

[0058] Preferably, the solid content of the mixed solution is 20% to 50%, for example, can be 20%, 25%, 30%, 35%, 40%, 45% or 50%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0059] Preferably, the temperature of the reaction is 55-65℃, for example, it can be 55℃, 56℃, 58℃, 60℃, 62℃, 64℃ or 65℃, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0060] Preferably, the time of the reaction is 24-36h, for example, it can be 24h, 25h, 27h, 28h, 30h, 32h, 35h or 36h, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0061] Preferably, the reaction is accompanied by condensation reflux and stirring.

[0062] Preferably, the temperature of the vacuum drying is 70-80℃, for example, it can be 70℃, 72℃, 75℃, 76℃, 78℃ or 80℃, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0063] Preferably, the time of the vacuum drying is 24h or more, for example, it can be 24h, 25h, 27h, 28h or 30h, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0064] The present application removes the unreacted reaction raw materials by vacuum drying, preventing the residual reaction raw materials from affecting the performance of the obtained solid-state electrolyte.

[0065] Preferably, after the vacuum drying, it further includes cyclohexane washing and dimethyl carbonate cleaning, and the washing endpoint is that there is no any one of the reaction raw materials in the washing liquid.

[0066] As an alternative technical solution, in the preparation raw materials of the vinylene carbonate-based polymer, the vinylene carbonate can be replaced by an equimolar amount of any one or a combination of at least two of vinyl ethylene carbonate, methyl methacrylate or maleic anhydride.

[0067] For example, the preparation method of the second polymer electrolyte layer of the present application includes the following steps:

[0068] Mix the vinylene carbonate-based polymer, succindinitrile and organic solvent according to the mass ratio (45-50):(1-3):(49-52) to obtain a second electrolyte mixture; mix the lithium salt with the first electrolyte mixture to obtain a second electrolyte slurry with a lithium salt concentration of 1.2-1.8mol / L; after coating the second electrolyte slurry to the desired thickness, remove the organic solvent by vacuum drying to obtain the second polymer electrolyte layer.

[0069] Preferably, the lithium salt comprises any one of or a combination of at least two of lithium bis-trifluoromethanesulfonylimide, lithium hexafluorophosphate (LIPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium tetrafluoro oxalato phosphate (LiTFOP), lithium trioxalato phosphate (LiTOP), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium bis(perfluoroethanesulfonyl)imide (LiFSI), lithium (trifluoromethylsulfonyl)(n-perfluorobutylsulfonyl)imide (LiFNTFSI), lithium (fluorosulfonyl)(n-perfluorobutylsulfonyl)imide (LiFNFSI), or lithium bis(oxalato)borate (LiBOB).

[0070] Preferably, the organic solvent comprises, but is not limited to, dimethyl sulfoxide.

[0071] Preferably, the temperature of the vacuum drying is 80-100 °C, for example, can be 80 °C, 85 °C, 90 °C, 95 °C, or 100 °C, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0072] Preferably, the time of the vacuum drying is > 24 h, for example, can be 24 h, 25 h, 27 h, 28 h, or 30 h, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0073] Preferably, the raw materials for preparing the sulfide electrolyte layer comprise a sulfide electrolyte, a lithium salt, and a binder.

[0074] Preferably, the raw materials for preparing the sulfide electrolyte layer comprise, in parts by weight:

[0075] a sulfide electrolyte 94-96 parts;

[0076] a lithium salt 2-3 parts;

[0077] a binder 2-3 parts.

[0078] The parts by weight of the sulfide electrolyte in the raw materials for preparing the sulfide electrolyte layer is 94-96 parts, for example, can be 94 parts, 94.5 parts, 95 parts, 95.5 parts, or 96 parts, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0079] The parts by weight of the lithium salt in the raw materials for preparing the sulfide electrolyte layer is 2-3 parts, for example, can be 2 parts, 2.1 parts, 2.4 parts, 2.5 parts, 2.7 parts, 2.8 parts, or 3 parts, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0080] The weight fraction of the binder in the raw material for preparing the sulfide electrolyte layer is 2 to 3 parts, and for example, can be 2 parts, 2.1 parts, 2.4 parts, 2.5 parts, 2.7 parts, 2.8 parts, or 3 parts, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0081] Preferably, the sulfide electrolyte layer satisfies at least one of the following conditions (a) to (c):

[0082] (a) The sulfide electrolyte includes Li6PS5Cl, Li2S-GeS2-P2S5, Li2S-SnS2-P2S5, 70Li2S-29P2S5-P2O5, Li 5.4 PS 4.4 Cl 1.6 , Li6PS5Cl 0.9 I 0.1 , Li 10 GeP2S 12 , Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , Li 10 SnP2S 12 , Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , Li 10 Si 0.5 Ge 0.5 P2S 12 , Li 10 Ge 0.5 Sn 0.5 P2S 12 , Li 10 Si 0.5 Sn 0.5 P2S 12 , Li 10 GeP2S 11.7 O 0.3 , Li 10.35 Ge 1.35 P 1.65 S 12 , Li 10.35 Si 1.35 P 1.65 S 12 , Li 9.81 Sn 0.81 P 2.19 S 12 , or Li 9.42 Si 1.02 P 2.1S 9.96 O 2.04 Any one or at least two of them;

[0083] (b) The lithium salt comprises any one or a combination of at least two of the following: lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate (LIPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium tetrafluorooxalate phosphate (LiTFOP), lithium trioxalate phosphate (LiTOP), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(perfluoroethylsulfonyl)imide (LiFSI), lithium (trifluoromethanesulfonyl)(perfluorobutylsulfonyl)imide (LiFNTFSI), lithium (fluorosulfonyl)(perfluorobutylsulfonyl)imide (LiFNFSI), or lithium bis(oxalobutylsulfonyl)borate (LiBOB);

[0084] (c) The adhesive comprises any one or at least two of the following: PEC, PPC, PVC, PMMA, PAA, Li-PAA, PAN, PDMS-POEM, PDMS-PEOCopolymer, PVDF, PEO, PET, PI, PIB, polystyrene (PS), styrene-butadiene-styrene (SBR), styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-butene-styrene copolymer (SEBS), acrylonitrile-butadiene-styrene block copolymer (ASB), nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), polyetheretherketone or polyether / polyester adhesives.

[0085] For example, the method for preparing the sulfide electrolyte layer of the present invention includes the following steps:

[0086] Lithium salt and binder are uniformly mixed to obtain a premix; sulfide electrolyte and premix are mixed, and the resulting mixture is subjected to first rolling, second rolling, sealing and leveling and warm isostatic pressing in sequence to obtain the sulfide electrolyte layer.

[0087] The sealing and leveling process includes placing the product from the second roller press between two stainless steel plates for sealing, and then removing the stainless steel plates. The thickness of the stainless steel plates is 80μm to 120μm, for example, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm or 120μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0088] Preferably, the temperature of the first rolling is 65-75 °C, for example it can be 65 °C, 66 °C, 68 °C, 70 °C, 72 °C or 75 °C, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0089] Preferably, the speed of the first rolling is 8-12 mm / s, for example it can be 8 mm / s, 9 mm / s, 10 mm / s, 11 mm / s or 12 mm / s, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0090] Preferably, the nip distance of the first rolling is 28-32 pm, for example it can be 28 pm, 29 pm, 30 pm, 31 pm or 32 pm, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0091] Preferably, the second rolling is a rolling of the product of the first rolling between 2 aluminum foils to obtain a composite.

[0092] Preferably, the thickness of the aluminum foil is 8-12 pm, for example it can be 8 pm, 9 pm, 10 pm, 11 pm or 12 pm, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0093] Preferably, the temperature of the second rolling is 65-75 °C, for example it can be 65 °C, 66 °C, 68 °C, 70 °C, 72 °C or 75 °C, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0094] Preferably, the speed of the second rolling is 8-12 mm / s, for example it can be 8 mm / s, 9 mm / s, 10 mm / s, 11 mm / s or 12 mm / s, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0095] Preferably, the nip distance of the second rolling is 38-42 pm, for example it can be 38 pm, 39 pm, 40 pm, 41 pm or 42 pm, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0096] Preferably, the pressure of the warm isostatic pressing is 450-540 MPa, for example it can be 450 MPa, 460 MPa, 470 MPa, 480 MPa, 490 MPa, 500 MPa, 510 MPa, 520 MPa, 530 MPa or 540 MPa, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0097] Preferably, the temperature of the warm isostatic pressing is 75-85℃, for example, it can be 75℃, 76℃, 77℃, 78℃, 80℃, 81℃, 82℃, 84℃ or 85℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0098] Preferably, the time of the warm isostatic pressing is 8-12min, for example, it can be 8min, 9min, 10min, 11min or 12min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0099] After the warm isostatic pressing, the aluminum foil is removed to obtain the sulfide electrolyte layer.

[0100] Preferably, the thickness of the first polymer electrolyte layer is 1-50μm, for example, it can be 1μm, 5μm, 10μm, 15μm, 20μm, 30μm, 40μm or 50μm, but is not limited to the listed values, and other values not listed in the value range are also applicable, preferably 5-20μm.

[0101] Preferably, the thickness of the second polymer electrolyte layer is 1-50μm, for example, it can be 1μm, 5μm, 10μm, 15μm, 20μm, 30μm, 40μm or 50μm, but is not limited to the listed values, and other values not listed in the value range are also applicable, preferably 5-20μm.

[0102] Preferably, the thickness of the sulfide electrolyte layer is 1-200μm, for example, it can be 1μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 40μm, 50μm, 60μm, 80μm, 100μm, 120μm, 150μm, 160μm, 180μm or 200μm, but is not limited to the listed values, and other values not listed in the value range are also applicable, preferably 15-30μm.

[0103] The preparation method of the solid-state electrolyte comprises the following steps:

[0104] Rolling the first polymer electrolyte layer, the sulfide electrolyte layer and the second polymer electrolyte layer to obtain the solid-state electrolyte.

[0105] In the second aspect, the present application provides an electrochemical device, which comprises the solid-state electrolyte of the first aspect.

[0106] Preferably, the electrochemical device comprises a lithium ion solid-state battery.

[0107] The lithium ion solid-state battery comprising the solid-state electrolyte has a wide electrochemical window.

[0108] In a third aspect, the present application provides an electronic device comprising the electrochemical device of the second aspect.

[0109] The numerical ranges recited herein are inclusive of the endpoints and not inclusive of any other points not recited, as limiting the scope of the application to specific embodiments, the present application is not intended to be limited to the specific numerical ranges recited.

[0110] Compared with the prior art, the present application has the following beneficial effects:

[0111] The present application sets the first polymer electrolyte layer comprising sulfolane-based polymer and the second polymer electrolyte layer comprising vinylene carbonate-based polymer on both sides of the sulfide electrolyte layer, so that the final obtained solid-state electrolyte has excellent ionic conductivity, electronic conductivity, electrochemical window and mechanical strength. DETAILED DESCRIPTION

[0112] In order to facilitate the description of the technical scheme provided by the present application, in the specific embodiment, the preparation method of the first polymer electrolyte layer comprises the following steps:

[0113] The sulfolane-based polymer, butanedinitrile and dimethyl sulfoxide are mixed in a mass ratio of 48:2:50 to obtain a first electrolyte mixture; LiTFSI is mixed with the first electrolyte mixture to obtain a first electrolyte slurry with a lithium salt concentration of 1.5 mol / L; after the first electrolyte slurry is coated to the required thickness, it is vacuum dried at 80℃ for 24h to remove dimethyl sulfoxide, and the first polymer electrolyte layer is obtained.

[0114] The preparation method of the second polymer electrolyte layer comprises the following steps:

[0115] The vinylene carbonate-based polymer, butanedinitrile and dimethyl sulfoxide are mixed in a mass ratio of 48:2:50 to obtain a second electrolyte mixture; LiTFSI is mixed with the second electrolyte mixture to obtain a second electrolyte slurry with a lithium salt concentration of 1.5 mol / L; after the second electrolyte slurry is coated to the required thickness, it is vacuum dried at 80℃ for 24h to remove dimethyl sulfoxide, and the second polymer electrolyte layer is obtained.

[0116] The above description is only used to illustrate the technical scheme of the present application, and should not be regarded as a specific limitation of the technical scheme of the present application.

[0117] The technical scheme of the present application is further illustrated by the specific embodiment.

[0118] Example 1

[0119] The embodiment provides a solid-state electrolyte, which comprises a first polymer electrolyte layer, a sulfide electrolyte layer and a second polymer electrolyte layer arranged in a stack;

[0120] The first polymer electrolyte layer comprises a sulfonol base polymer;

[0121] The second polymer electrolyte layer comprises a vinylene carbonate base polymer.

[0122] The preparation method of the sulfonol base polymer comprises the following steps:

[0123] The propenyl-1,3-sulfonol, ethylene sulfone, PEGMEMA and azobisisobutyronitrile are mixed in a proportion of 94 mol%, 3 mol%, 2.5 mol% and 0.5 mol% by mole percentage, to obtain a mixed solution (the solvent is cyclohexane) with a solid content of 35%; the reaction is carried out at 60 DEG C for 30 h, and the reaction is accompanied by condensation reflux and stirring, to obtain a polymer material; the obtained polymer material is crushed and vacuum dried at 80 DEG C for 24 h, and then washed, to obtain the sulfonol base polymer.

[0124] The preparation method of the vinylene carbonate base polymer comprises the following steps:

[0125] The vinylene carbonate, ethylene glycol diacrylate, PEGMEMA and azobisisobutyronitrile are mixed in a proportion of 94 mol%, 3 mol%, 2.5 mol% and 0.5 mol% by mole percentage, to obtain a mixed solution (the solvent is cyclohexane) with a solid content of 35%; the reaction is carried out at 60 DEG C for 30 h, and the reaction is accompanied by condensation reflux and stirring, to obtain a polymer material; the obtained polymer material is crushed and vacuum dried at 80 DEG C for 24 h, and then washed, to obtain the vinylene carbonate base polymer.

[0126] The preparation method of the sulfide electrolyte layer comprises the following steps:

[0127] The 2.5 parts of lithium bis-trifluoromethylsulfonylimide and 2.5 parts of PVDF are uniformly mixed to obtain a premix; the premix and 95 parts of Li6PS5Cl are mixed, and the obtained mixture is sequentially subjected to first rolling, second rolling, sealing leveling and warm isostatic pressing; after the warm isostatic pressing, the aluminum foil is removed, to obtain the sulfide electrolyte layer;

[0128] The first rolling is performed at a temperature of 70℃, a speed of 10mm / s and a roller distance of 30μm; the second rolling is performed by placing the product of the first rolling between two aluminum foils with a thickness of 10μm to obtain a composite, and the second rolling is performed at a temperature of 70℃, a speed of 10mm / s and a roller distance of 40μm; the sealing and flattening includes placing the composite between two stainless steel plates with a thickness of 100μm, and then removing the stainless steel plates; the warm isostatic pressing is performed at a pressure of 500MPa and a temperature of 80℃ for 10min.

[0129] The preparation method of the solid-state electrolyte comprises the following steps:

[0130] The first polymer electrolyte layer, the sulfide electrolyte layer and the second polymer electrolyte layer are rolled to obtain the solid-state electrolyte; in the obtained solid-state electrolyte, the thickness of the first polymer electrolyte layer is 10μm, the thickness of the sulfide electrolyte layer is 25μm, and the thickness of the second polymer electrolyte layer is 10μm.

[0131] Example 2

[0132] The present embodiment provides a solid-state electrolyte, which comprises a first polymer electrolyte layer, a sulfide electrolyte layer and a second polymer electrolyte layer arranged in a stack;

[0133] The first polymer electrolyte layer comprises a sulfonolactone-based polymer;

[0134] The second polymer electrolyte layer comprises a vinylene carbonate-based polymer.

[0135] The preparation method of the sulfonolactone-based polymer comprises the following steps:

[0136] The propenyl-1,3-sulfonolactone, ethylene sulfone, PEGMEMA and azobisisobutyronitrile are mixed in a molar percentage ratio of 93mol%, 3.5mol%, 2.7mol% and 0.8mol% to obtain a mixed solution with a solid content of 20% (the solvent is cyclohexane); the reaction is performed at 55℃ for 36h, accompanied by condensation reflux and stirring, to obtain a polymer material; the obtained polymer material is crushed and vacuum dried at 70℃ for 24h, and then washed to obtain the sulfonolactone-based polymer.

[0137] The preparation method of the vinylene carbonate-based polymer comprises the following steps:

[0138] Mixing 93.4 mol%, 3.2 mol%, 2.7 mol% and 0.6 mol% of vinylene carbonate, ethylene glycol diacrylate, PEGMEMA and azobisisobutyronitrile by mole percentage, to obtain a mixture with solid content of 20% (solvent is cyclohexane); reacting at 55℃ for 36h, with condensation reflux and stirring, to obtain a polymer material; crushing the obtained polymer material and drying at 70℃ under vacuum for 24h, to obtain the vinylene carbonate-based polymer.

[0139] The preparation method of the sulfide electrolyte layer comprises the following steps:

[0140] Mixing 3 parts by weight of lithium bistrifluoromethylsulfonylimide and 3 parts by weight of PVDF to obtain a premix; mixing the premix with 94 parts by weight of Li6PS5Cl, and sequentially performing first rolling, second rolling, sealing and flattening, and warm isostatic pressing on the obtained mixture, removing the aluminum foil after warm isostatic pressing, to obtain the sulfide electrolyte layer;

[0141] The temperature of the first rolling is 65℃, the speed is 8mm / s, and the distance between the rollers is 32μm; the second rolling is to place the product of the first rolling between two aluminum foils with a thickness of 8μm for rolling, to obtain a composite, the temperature of the second rolling is 65℃, the speed is 8mm / s, and the distance between the rollers is 42μm; the sealing and flattening comprises placing the composite between two stainless steel plates with a thickness of 120μm for sealing, and then removing the stainless steel plates; the pressure of the warm isostatic pressing is 450MPa, the temperature is 75℃, and the time is 12min.

[0142] The preparation method of the solid-state electrolyte comprises the following steps:

[0143] Rolling the first polymer electrolyte layer, the sulfide electrolyte layer and the second polymer electrolyte layer to obtain the solid-state electrolyte; in the obtained solid-state electrolyte, the thickness of the first polymer electrolyte layer is 20μm, the thickness of the sulfide electrolyte layer is 30μm, and the thickness of the second polymer electrolyte layer is 20μm.

[0144] Example 3

[0145] The present embodiment provides a solid-state electrolyte, which comprises a first polymer electrolyte layer, a sulfide electrolyte layer and a second polymer electrolyte layer arranged in layers;

[0146] The first polymer electrolyte layer comprises a sulfonolactone-based polymer;

[0147] The second polymer electrolyte layer comprises a vinylene carbonate-based polymer.

[0148] The preparation method of the sulfonolactone-based polymer comprises the following steps:

[0149] Mixing propenyl-1,3-sultone, vinyl sulfone, PEGMEMA and azobisisobutyronitrile in a ratio of 95 mol%, 2.5 mol%, 2.2 mol% and 0.3 mol% by mole percentage, to obtain a mixed solution (solvent is cyclohexane) with a solid content of 50%; reacting at 65℃ for 24h, with condensation reflux and stirring, to obtain a polymer material; crushing the obtained polymer material and drying at 80℃ under vacuum for 24h, to obtain the sultone-based polymer.

[0150] The preparation method of the vinylene carbonate-based polymer comprises the following steps:

[0151] Mixing vinylene carbonate, ethylene glycol diacrylate, PEGMEMA and azobisisobutyronitrile in a ratio of 94.6 mol%, 2.8 mol%, 2.4 mol% and 0.2 mol% by mole percentage, to obtain a mixed solution (solvent is cyclohexane) with a solid content of 50%; reacting at 65℃ for 24h, with condensation reflux and stirring, to obtain a polymer material; crushing the obtained polymer material and drying at 80℃ under vacuum for 24h, to obtain the vinylene carbonate-based polymer.

[0152] The preparation method of the sulfide electrolyte layer comprises the following steps:

[0153] Uniformly mixing 2 parts by weight of lithium bistrifluoromethylsulfonylimide and 2 parts by weight of PVDF to obtain a premix; mixing the premix and 96 parts by weight of Li6PS5Cl, and sequentially performing first rolling, second rolling, sealing and leveling, and warm isostatic pressing on the obtained mixture, removing the aluminum foil after warm isostatic pressing, to obtain the sulfide electrolyte layer;

[0154] The temperature of the first rolling is 75℃, the speed is 12mm / s, and the distance between the rollers is 28μm; the second rolling is to place the product of the first rolling between two aluminum foils with a thickness of 12μm for rolling, to obtain a composite, the temperature of the second rolling is 75℃, the speed is 12mm / s, and the distance between the rollers is 38μm; the sealing and leveling comprises placing the composite between two stainless steel plates with a thickness of 80μm for sealing, and then removing the stainless steel plates; the pressure of the warm isostatic pressing is 540MPa, the temperature is 85℃, and the time is 8min.

[0155] The preparation method of the solid-state electrolyte comprises the following steps:

[0156] Rolling the first polymer electrolyte layer, the sulfide electrolyte layer and the second polymer electrolyte layer to obtain the solid-state electrolyte; in the obtained solid-state electrolyte, the thickness of the first polymer electrolyte layer is 5μm, the thickness of the sulfide electrolyte layer is 15μm, and the thickness of the second polymer electrolyte layer is 5μm.

[0157] Examples 4 to 5 are the same as Example 1 except for the change of the second sulfur-containing polymer monomer in Table 2.

[0158] Examples 6 to 10 are the same as Example 1 except for the change of the first sulfur-containing polymer monomer in Table 3.

[0159] Comparative Example 1 is the same as Example 1 except for the replacement of the first polymer electrolyte layer with the second polymer electrolyte layer.

[0160] Comparative Example 2 is the same as Example 1 except for the replacement of the second polymer electrolyte layer with the first polymer electrolyte layer.

[0161] Comparative Example 3 provides a solid-state electrolyte including only the first polymer electrolyte layer and the sulfide electrolyte layer in Example 1, and the preparation method and composition are the same as Example 1.

[0162] Comparative Example 4 provides a solid-state electrolyte including only the sulfide electrolyte layer and the second polymer electrolyte layer in Example 1, and the preparation method and composition are the same as Example 1.

[0163] Comparative Example 5 provides a solid-state electrolyte including only the sulfide electrolyte layer in Example 1.

[0164] Performance Test

[0165] Ionic conductivity: The solid-state electrolyte was punched in an argon glove box, and a mold cell was used for ion single conductivity test, and the test conditions were: diameter 10 mm, test pressure 200 MPa, and an impedance analyzer (model Bio-logic MTZ-35) was used for test, and the frequency was 35 MHz to 0.1 Hz.

[0166] Electronic conductivity: In an argon glove box, at 25℃, a stainless steel blocking electrode, a solid-state electrolyte and a stainless steel blocking electrode were sequentially stacked and assembled into a cell by applying a pressure of 200 MPa, and then a constant voltage of 0.5V was applied to the cell for direct polarization for 3000s, and the current I after 3000s was recorded, then,

[0167] Electronic resistance = constant voltage ÷ current = 0.5 ÷ I,

[0168] Electronic conductivity = thickness of solid-state electrolyte ÷ (electronic resistance × area of solid-state electrolyte).

[0169] Electrochemical window: Assemble Li|solid-state electrolyte|SUS button cell, i.e. the solid-state electrolyte side is a lithium ion blocking electrode stainless steel sheet, and the other side is a lithium ion reversible electrode lithium copper composite strip, in a glove phase at 25°C. The cyclic voltammetry scan voltage is first scanned from the open circuit voltage to-0.5V, and then from-0.5V to 10V, and so on. The scanning speed is 0.5mV / s, and the starting oxidation current position of the battery is confirmed.

[0170] Tensile strength: The tensile strength of the solid-state electrolyte is tested using a battery separator tensile strength tester (Labthink Lan light, model XLW tensile tester).

[0171] The test results are shown in Tables 1 to 4.

[0172] Table 1

[0173]

[0174] Table 2

[0175]

[0176] Table 3

[0177]

[0178] Table 4

[0179]

[0180] It can be seen from Table 1 that the solid-state electrolyte provided by the application has an ionic conductivity of 4.2mS / cm or more, an electronic conductivity of 1.1mS / cm or more, a tensile strength of 100kgf / cm 2 , and a wide electrochemical window.

[0181] It can be seen from Table 2 that changing the type of the second sulfur-containing polymer monomer, the obtained solid-state electrolyte still has high ionic conductivity, electronic conductivity and tensile strength, but the electrochemical window is slightly reduced. The effect is best when the second sulfur-containing polymer monomer is ethylene sulfone.

[0182] It can be seen from Table 3 that changing the type of the first sulfur-containing polymer monomer, the obtained solid-state electrolyte has high ionic conductivity and electronic conductivity, but the electrochemical window is slightly reduced. The effect is best when the first sulfur-containing polymer monomer is propenyl-1,3-sulfonyl lactone.

[0183] It can be seen from Table 4 that the structure of the solid-state electrolyte described in the application is beneficial to realize high ionic conductivity, high electronic conductivity, wide electrochemical window and high tensile strength.

[0184] In summary, the present application provides a final solid-state electrolyte with excellent ionic conductivity, electronic conductivity, electrochemical window, and mechanical strength by disposing a first polymer electrolyte layer including a sulfonolactone-based polymer and a second polymer electrolyte layer including a vinylene carbonate-based polymer on both sides of a sulfide electrolyte layer.

[0185] Applicant declares that the present application is illustrated by the above-mentioned embodiments, but the present application is not limited to the above-mentioned detailed methods, i.e. it does not mean that the present application must rely on the above-mentioned detailed methods to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific methods, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A solid state electrolyte, characterized by, The solid-state electrolyte comprises a first polymer electrolyte layer, a sulfide electrolyte layer, and a second polymer electrolyte layer arranged in a stack; The first polymer electrolyte layer is arranged on the positive electrode side of the sulfide electrolyte layer; and the second polymer electrolyte layer is arranged on the negative electrode side of the sulfide electrolyte layer; The first polymer electrolyte layer comprises a sulfonol base polymer; and a monomer of the sulfonol base polymer comprises a sulfonol with an unsaturation degree of ≥1; The second polymer electrolyte layer comprises a vinylene carbonate base polymer; Preparation raw materials of the sulfonol base polymer comprise a first sulfur-containing polymer monomer, a second sulfur-containing polymer monomer, a polymer additive monomer, and an initiator; The first sulfur-containing polymer monomer comprises: , , , , or any one of or a combination of at least two of The second sulfur-containing polymer monomer comprises: , or any one of or a combination of at least two of Preparation raw materials of the vinylene carbonate base polymer comprise vinylene carbonate, ethylene glycol diacrylate, a polymer additive monomer, and an initiator.

2. The solid-state electrolyte of claim 1, wherein, Preparation raw materials of the sulfide electrolyte layer comprise a sulfide electrolyte, a lithium salt, and a binder.

3. The solid-state electrolyte of claim 2, wherein, The sulfide electrolyte layer satisfies at least one of the following conditions (a) to (c): (a) the sulfide electrolyte comprises any one of Li6PS5Cl, Li2S-GeS2-P2S5, Li2S-SnS2-P2S5, 70Li2S-29P2S5-P2O5, Li 5.4 PS 4.4 Cl 1.6 , Li6PS5Cl 0.9 I 0.1 , Li 10 GeP2S 12 , Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , Li 10 SnP2S 12 , Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , Li 10 Si 0.5 Ge 0.5 P2S 12 , Li 10 Ge 0.5 Sn 0.5 P2S 12 , Li 10 Si 0.5 Sn 0.5 P2S 12 , Li 10 GeP2S 11.7 O 0.3 , Li 10.35 Ge 1.35 P 1.65 S 12 , Li 10.35 Si 1.35 P 1.65 S 12 , Li 9.81 Sn 0.81 P 2.19 S 12 , or Li 9.42 Si 1.02 P 2.1 S 9.96 O 2.04 , or a combination of at least two thereof; (b) The lithium salt comprises any one or a combination of at least two of lithium bis(trifluoromethylsulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium trifluoromethylsulfonate, lithium tetrafluoro-oxalate-phosphate, lithium tri-oxalate-phosphate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(perfluoroethylsulfonyl)imide, lithium (trifluoromethylsulfonyl)(n-perfluorobutylsulfonyl)imide, lithium (fluorosulfonyl)(n-perfluorobutylsulfonyl)imide, or lithium bis-oxalate-borate; (c) The binder comprises any one or a combination of at least two of PEC, PPC, PVC, PMMA, PAA, Li-PAA, PAN, PDMS-POE, PDMS-PEO copolymer, PVDF, PEO, PET, PI, PIB, polystyrene, butadiene-styrene rubber, styrene-butadiene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, acrylonitrile-butadiene-styrene block copolymer, nitrile rubber, hydrogenated nitrile rubber, or polyether ether ketone.

4. The solid-state electrolyte of claim 1, wherein, The thickness of the first polymer electrolyte layer is 1 μm to 50 μm.

5. The solid-state electrolyte of claim 4, wherein, The thickness of the first polymer electrolyte layer is 5 μm to 20 μm.

6. The solid-state electrolyte of claim 4, wherein, The thickness of the second polymer electrolyte layer is 1 μm to 50 μm.

7. The solid-state electrolyte of claim 6, wherein, The thickness of the second polymer electrolyte layer is 5 μm to 20 μm.

8. The solid-state electrolyte of claim 4 or 6, wherein, The thickness of the sulfide electrolyte layer is 1 μm to 200 μm.

9. The solid-state electrolyte of claim 8, wherein, The thickness of the sulfide electrolyte layer is 15-30 μm.

10. An electrochemical device, characterized by, The electrochemical device comprises the solid-state electrolyte according to any one of claims 1 to 9.

11. An electronic device, comprising: The electronic device comprises the electrochemical device according to claim 10.

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