CN115133111B - Composite electrolyte, preparation method thereof and lithium ion battery - Google Patents

Composite electrolyte, preparation method thereof and lithium ion battery Download PDF

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CN115133111B
CN115133111B CN202211050810.9A CN202211050810A CN115133111B CN 115133111 B CN115133111 B CN 115133111B CN 202211050810 A CN202211050810 A CN 202211050810A CN 115133111 B CN115133111 B CN 115133111B
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solid electrolyte
ionic liquid
electrolyte layer
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冯玉川
李峥
何泓材
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Qingtao Kunshan Energy Development Co ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0088—Composites
    • H01M2300/0094—Composites in the form of layered products, e.g. coatings
    • H01M2300/0097—Composites in the form of layered products, e.g. coatings with adhesive layers
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    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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Abstract

The composite electrolyte at least comprises an inorganic solid electrolyte layer and organic solid electrolyte layers arranged on two sides of the inorganic solid electrolyte layer, wherein the organic solid electrolyte layer comprises a pore structure with the pore diameter smaller than 100nm and comprises polymer solid electrolyte, lithium salt, first ionic liquid, second ionic liquid and succinonitrile, and the inorganic solid electrolyte layer at least comprises sulfide solid electrolyte. This application is through adding first and the second ionic liquid that dissolve the performance difference mutually with polymer solid electrolyte for first ionic liquid can be with the better complex of nanopore structure, and the complex of first ionic liquid and battery can not ooze, makes the second ionic liquid be located more on inorganic solid electrolyte layer and organic solid electrolyte layer's interface, promotes the lithium ion transmission.

Description

Composite electrolyte, preparation method thereof and lithium ion battery
Technical Field
The application relates to the technical field of batteries, in particular to a composite electrolyte, a preparation method thereof and a lithium ion battery.
Background
Liquid lithium ion batteries are currently widely used energy storage devices, but liquid electrolytes are combustible and explosive, and the safety cannot be guaranteed. Solid electrolytes are well known for their high safety, and have the advantages of excellent thermal and electrochemical stability, wide electrochemical window, excellent mechanical properties, etc.
The solid electrolyte is divided into a ceramic solid electrolyte and an organic polymer solid electrolyte, wherein the organic polymer solid electrolyte mainly takes PEO (polyethylene oxide) as a main component, and the lithium ion transmission is realized through complexation and decomplexing of lithium ions by ether oxygen in the PEO. However, both organic polymer solid electrolytes and ceramic solid electrolytes have their own defects, so that in the prior art, composite solid electrolytes are produced, and organic and inorganic solid electrolytes are composited to realize the combination of the two electrolytes so as to improve the overall performance, but the interface impedance between the organic and inorganic solid electrolyte layers of the composite solid electrolyte is not favorable for the transmission of lithium ions.
The existing research shows that the application of the ionic liquid in the battery is beneficial, but the current common method is to directly mix the ionic liquid with the battery component, on one hand, the ionic liquid in the battery cannot form effective interaction with the battery component due to the mixing mode, and the ionic liquid is in a liquid state, so that the ionic liquid can be separated from a pole piece and a solid electrolyte in the use process, and the bonding strength is not high. On the other hand, the pore structure formed in the existing polymer solid electrolyte is difficult to reach the nanometer scale, and the dispersion is not uniform, which is not beneficial to maintaining the overall performance of the solid electrolyte layer.
In previous studies, the applicant found that the crystalline compound and succinonitrile, ionic liquid can generate beneficial interaction, and a desired pore channel structure is formed in the polymer solid electrolyte membrane to fix the ionic liquid.
Therefore, it is desirable to provide a new electrolyte to solve the above problems.
Disclosure of Invention
In order to solve one or more technical problems in the prior art, embodiments of the present application provide a composite electrolyte, a preparation method thereof, and a lithium ion battery, so as to solve the problems in the prior art.
In order to achieve the above purpose, the technical solution adopted by the present application to solve the technical problem is:
in a first aspect, the present application provides a composite electrolyte comprising at least an inorganic solid electrolyte layer and organic solid electrolyte layers disposed on both sides of the inorganic solid electrolyte layer;
the organic solid electrolyte layer comprises a pore structure with a pore diameter of less than 100 nm;
the components of the organic solid electrolyte layer comprise a polymer solid electrolyte, a lithium salt, a first ionic liquid, a second ionic liquid and succinonitrile;
the inorganic solid electrolyte layer has a composition including at least a sulfide solid electrolyte.
Preferably, the pore structure has a pore diameter of less than 80nm.
In a specific embodiment, the first ionic liquid is dispersed in the pore structure, preferably the ionic liquid is uniformly dispersed in the pore structure, and the second ionic liquid is at least partially located at the interface of the inorganic solid state electrolyte layer and the organic solid state electrolyte layer.
In a specific embodiment, the mutual solubility of the first ionic liquid and the polymer solid electrolyte is better than the mutual solubility of the second ionic liquid and the polymer solid electrolyte.
In a specific embodiment, the first ionic liquid comprises an imidazole ionic liquid, and the second ionic liquid comprises a piperidine ionic liquid.
Preferably, the first ionic liquid comprises 1-butyl-3-methylimidazolium chloride and the second ionic liquid comprises methylpropylpiperidinbis (trifluoromethylsulfonyl) imide.
In a specific embodiment, the polymer solid electrolyte comprises a crystalline polymer.
The crystalline polymer means that the polymer has a property of being able to crystallize, and in an actual polymer solid electrolyte, it has a two-phase composition of crystalline and amorphous states.
In a particular embodiment, the polymer solid electrolyte comprises at least a partially crystalline polymer and consists of at least two phases, a crystalline and an amorphous phase.
In a specific embodiment, the polymer solid electrolyte comprises one or more of polyethylene oxide, polyvinylidene fluoride, polymethyl methacrylate, polyvinylidene fluoride-co-hexafluoropropylene, polyurethane acrylate, polyethylene glycol, and polyvinyl alcohol.
In a particular embodiment, the polymer solid electrolyte is capable of forming a porous structure under the action of succinonitrile.
In a specific embodiment, the organic solid electrolyte layer further includes a ceramic powder.
Preferably, the ceramic powder is a fast ion conductor;
preferably, the fast ion conductor is one or more of oxide solid electrolyte, sulfide solid electrolyte, halide solid electrolyte, boride solid electrolyte, nitride solid electrolyte and hydride solid electrolyte;
further preferably, the oxide solid electrolyte includes LLZTO powder and/or LATP powder.
In a specific embodiment, the particle size of the ceramic powder is less than 1 μm; preferably, the particle size of the ceramic powder is less than 500nm; further preferably, the particle diameter of the ceramic powder is smaller than the pore diameter of the pore structure.
In a specific embodiment, the lithium salt includes one or a mixture of lithium bistrifluoromethylsulfonate imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate and lithium difluorosulfonamide.
In a specific embodiment, the composition of the organic solid electrolyte layer comprises, in mass percent:
30-60wt% of polymer solid electrolyte, 1-10wt% of first and second ionic liquids, 15-30wt% of lithium salt, 10-30wt% of succinonitrile and 10-30wt% of ceramic powder.
Preferably, the proportion of succinonitrile is 15 to 25wt%.
In a second aspect, the present application also provides a method for producing a composite electrolyte, corresponding to the composite electrolyte described above, the method comprising:
dispersing a polymer solid electrolyte, a first ionic liquid and a lithium salt into a first solvent according to a preset proportion, and mixing to obtain a first mixture;
adding succinonitrile with preset mass into the first mixture, and mixing to obtain a second mixture;
drying the second mixture and preparing a film to obtain a polymer solid electrolyte film;
soaking the polymer solid electrolyte membrane in a second ionic liquid to obtain an organic solid electrolyte layer, wherein the organic solid electrolyte layer comprises a pore structure with the pore diameter of less than 100 nm;
dissolving a sulfide solid electrolyte and a binder in a second solvent to form solid electrolyte slurry, coating the solid electrolyte slurry on a release film, and drying to obtain an inorganic solid electrolyte layer;
and laminating the organic solid electrolyte layer on two sides of the inorganic solid electrolyte layer to form a composite electrolyte, wherein the first ionic liquid is dispersed in the pore structure, at least part of the second ionic liquid is positioned on the interface of the inorganic solid electrolyte layer and the organic solid electrolyte layer, and the mutual dissolving performance of the first ionic liquid and the polymer solid electrolyte is better than that of the second ionic liquid and the polymer solid electrolyte.
In a third aspect, the present application further provides a lithium ion battery corresponding to the above composite electrolyte, where the lithium ion battery includes a positive electrode plate, a negative electrode plate, and the above composite electrolyte.
The technical scheme provided by the embodiment of the application has the following beneficial effects:
the composite electrolyte comprises at least an inorganic solid electrolyte layer and organic solid electrolyte layers arranged on two sides of the inorganic solid electrolyte layer, wherein the organic solid electrolyte layer comprises a pore structure with the pore diameter smaller than 100nm, the components of the organic solid electrolyte layer comprise polymer solid electrolyte, lithium salt, first ionic liquid, second ionic liquid and succinonitrile, the components of the inorganic solid electrolyte layer at least comprise sulfide solid electrolyte, on one hand, the succinonitrile is mixed with the polymer solid electrolyte layer by utilizing the pore-forming effect of the succinonitrile on crystalline polymers, and the polymer solid electrolyte layer (namely the organic solid electrolyte layer) containing uniform nanopores is prepared through proper technological parameters.
Furthermore, the composite electrolyte provided by the application has high ionic conductivity and mechanical property and excellent electrode/electrolyte interface wettability, and an electric double layer is prevented from being generated on an interface.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.
As described in the background, the electrolytes of the prior art each have their own drawbacks, thus producing a composite solid electrolyte, which is compounded with organic and inorganic solid electrolytes in the hope of achieving a combination of both to improve the overall performance. On the basis, in order to solve one or more of the problems, the application creatively provides a novel composite electrolyte prepared by a solution casting method, the composite electrolyte has high ionic conductivity, high ion migration number and a wide electrochemical stability window, can be matched with a high-voltage positive electrode material (including but not limited to modified lithium cobaltate, ternary nickel cobalt aluminum, nickel cobalt manganese, lithium-rich manganese and the like), and under the condition of high temperature, the micropores of the electrolyte are deformed and amplified, ionic liquid is released and soaked in the gaps of the positive electrode material, so that the surface of active substance particles is passivated, and the high-temperature safety of the electrode is improved.
The following optional technical solutions are used as optional technical solutions of the present application, but not as limitations on the technical solutions provided by the present application, and the technical purposes and beneficial effects of the present application can be better achieved and achieved through the following optional technical solutions.
The composite electrolyte provided by the embodiment of the application at least comprises an inorganic solid electrolyte layer and organic solid electrolyte layers arranged on two sides of the inorganic solid electrolyte layer, wherein the organic solid electrolyte layer is in a jelly shape and comprises polymer solid electrolyte, lithium salt, first ionic liquid, second ionic liquid and succinonitrile, and the organic solid electrolyte layer comprises a pore structure with the pore diameter smaller than 100 nm; preferably, the pore size is less than 80nm. The inorganic solid electrolyte layer contains at least a sulfide solid electrolyte as a component.
In the examples of the present application, without being particularly limited, the sulfide solid state electrolyte contained in the inorganic solid state electrolyte layer in the present application may include one or more sulfide-based materials selected from the following without departing from the inventive concept of the present application:
Figure 494686DEST_PATH_IMAGE001
、
Figure 942985DEST_PATH_IMAGE002
(wherein M is Si, ge or Sn and 0. Ltoreq. X.ltoreq.2),
Figure 785039DEST_PATH_IMAGE003
、
Figure 196560DEST_PATH_IMAGE004
、
Figure 338829DEST_PATH_IMAGE005
、
Figure 692449DEST_PATH_IMAGE006
、
Figure 693904DEST_PATH_IMAGE007
、
Figure 968503DEST_PATH_IMAGE008
、
Figure 699698DEST_PATH_IMAGE009
、
Figure 506111DEST_PATH_IMAGE010
、
Figure 322758DEST_PATH_IMAGE011
、
Figure 872819DEST_PATH_IMAGE012
、
Figure 927362DEST_PATH_IMAGE013
(wherein X is Cl, br or I),
Figure 622786DEST_PATH_IMAGE014
、
Figure 677461DEST_PATH_IMAGE015
、
Figure 749322DEST_PATH_IMAGE016
、
Figure 658372DEST_PATH_IMAGE017
、
Figure 803658DEST_PATH_IMAGE018
、
Figure 860476DEST_PATH_IMAGE019
、
Figure 221181DEST_PATH_IMAGE020
(wherein 0.5. Ltoreq. X. Ltoreq.0.7) and combinations thereof. In one variation, the one or more sulfide-based materials can have a composition of greater than or equal to about
Figure 250317DEST_PATH_IMAGE021
To an ionic conductivity of less than or equal to about 1S/cm.
As a preferred embodiment, in the present embodiment, the first ionic liquid is dispersed in the pore structure, preferably, the first ionic liquid is uniformly dispersed in the pore structure, and the second ionic liquid is at least partially located at the interface between the inorganic solid electrolyte layer and the organic solid electrolyte layer.
Specifically, the ionic liquid is in a liquid state at room temperature or close to room temperature, and has some excellent characteristics, such as incombustibility, negligible vapor pressure, thermal stability, high ionic conductivity, wide electrochemical stability window and the like, by adding the first ionic liquid and the second ionic liquid and utilizing the characteristics of the ionic liquid, the prepared composite electrolyte has high ionic conductivity, high ionic migration number and wide electrochemical stability window, can be matched with a high-voltage positive electrode material, and under the high-temperature condition, the micropores of the composite electrolyte are deformed and amplified, the first ionic liquid and the second ionic liquid are released and immersed into the gaps of the positive electrode material, so that the surfaces of active substance particles are passivated, the high-temperature lattice oxygen evolution phenomenon of the positive electrode material is inhibited, and the high-temperature safety of the electrode is improved.
When the method is specifically implemented, the first ionic liquid is dispersed in the pore structure, so that the first ionic liquid can be better compounded with the nanopore structure, seepage is prevented, and the second ionic liquid is at least partially positioned on the interface between the inorganic solid electrolyte layer and the organic solid electrolyte layer, so that lithium ion transmission can be promoted.
As a preferred embodiment, in the present embodiment, the mutual solubility of the first ionic liquid and the polymer solid electrolyte is better than that of the second ionic liquid and the polymer solid electrolyte.
Preferably, the first ionic liquid comprises an imidazole ionic liquid, the cation of the imidazole ionic liquid can be ethylmethylimidazole (EMIm), methylpropylimidazole (PMIm), butylmethylimidazole (BMIm), and further preferably, the first ionic liquid comprises 1-butyl-3-methylimidazolium chloride.
Preferably, the second ionic liquid comprises a piperidine ionic liquid, the cation of which may be ethyl methyl piperidine (EMPip), methyl propyl piperidine (PMPip) and butyl methyl piperidine (BMPip), and further preferably, the second ionic liquid comprises methyl propyl piperidine bis (trifluoromethylsulfonyl) imide.
Preferably, the mass ratio of the first ionic liquid to the second ionic liquid is 2-4; preferably, the mass ratio of the first ionic liquid to the second ionic liquid is 3-4.
Because the piperidine ionic liquid and the polymer solid electrolyte (such as PEO and the like) are not mutually dissolved, the piperidine ionic liquid is more positioned on the interface of the organic solid electrolyte layer and the inorganic solid electrolyte, and is positioned on the phase boundary due to the low mutual solubility of the piperidine ionic liquid in the polymer solid electrolyte, and the lithium ion transmission is promoted.
In the present example, the polymer solid electrolyte comprises a crystalline polymer. Preferably, the crystalline polymer comprises polyethylene oxide (PEO).
Preferably, the polymer solid electrolyte comprises at least a partially crystalline polymer and consists of at least two phases, a crystalline phase and an amorphous phase.
Preferably, the polymer solid electrolyte comprises one or a mixture of several of polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), polyurethane acrylate (PUA), polyethylene glycol (PEG) and polyvinyl alcohol (PVA).
Preferably, the polymer solid electrolyte is a mixture of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) and polyethylene glycol (PEG).
Further preferably, the mass ratio of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) to polyethylene glycol (PEG) is 5.
In the examples of the present application, the polymer solid electrolyte can form a porous structure by the action of succinonitrile.
Specifically, succinonitrile is an organic compound, is a colorless and odorless waxy solid, is slightly soluble in water, ethanol, benzene, diethyl ether, and carbon disulfide, is soluble in acetone, chloroform, dioxane, and the like, and is a commonly used organic synthetic raw material. In the embodiment of the application, the crystalline phase of the crystalline polymer can be inhibited by adding the succinonitrile, and a porous structure can be formed when the added succinonitrile reaches a certain proportion. Generally, the mass ratio of succinonitrile is required to be more than 10%, that is, a porous structure can be formed, and if the content of succinonitrile is too high, the porosity is too high.
As a matter of guesswork only, not as any limitation of the scope of protection, the introduction of succinonitrile may result in a reduced proportion of crystalline phases in the crystalline polymer, which in turn results in a porous structure.
As a preferred embodiment, in the present application example, the organic solid electrolyte layer further includes ceramic powder;
preferably, the ceramic powder is a fast ion conductor;
preferably, the fast ion conductor is one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a boride solid electrolyte, and a nitride solid electrolyte. Further preferably, the oxide solid electrolyte includes LLZTO powder and/or LATP powder.
As an embodiment, the oxide solid state electrolyte may comprise one or more of garnet ceramics, LISICON-type oxides, NASICON-type oxides, and perovskite-type ceramics. For example, the one or more garnet ceramics may be selected from the group comprising:
Figure 553122DEST_PATH_IMAGE022
、
Figure 34919DEST_PATH_IMAGE023
、
Figure 651845DEST_PATH_IMAGE024
、
Figure 82958DEST_PATH_IMAGE025
、
Figure 556665DEST_PATH_IMAGE026
、
Figure 525758DEST_PATH_IMAGE027
and combinations thereof. The one or more LISICON-type oxides may be selected from the group comprising:
Figure 228266DEST_PATH_IMAGE028
、
Figure 231994DEST_PATH_IMAGE029
(wherein 0)<x<1）、
Figure 407760DEST_PATH_IMAGE030
(wherein 0)<x<1) And combinations thereof. One or more NASICON type oxides may be prepared from
Figure 900969DEST_PATH_IMAGE031
Definitions, wherein M and
Figure 453173DEST_PATH_IMAGE032
independently selected from Al, ge, ti, sn, hf, zr and La. For example, in certain variations, the one or more NASICON-type oxides may be selected from the group consisting of:
Figure 390036DEST_PATH_IMAGE033
(wherein x is not less than 0 and not more than 2),
Figure 956277DEST_PATH_IMAGE034
(wherein x is not less than 0 and not more than 2),
Figure 634383DEST_PATH_IMAGE035
(wherein x is not less than 0 and not more than 2),
Figure 272169DEST_PATH_IMAGE036
、
Figure 516069DEST_PATH_IMAGE037
、
Figure 236900DEST_PATH_IMAGE038
、
Figure 415684DEST_PATH_IMAGE039
、
Figure 247374DEST_PATH_IMAGE040
And combinations thereof. The one or more perovskite-type ceramics may be selected from the group comprising:
Figure 611359DEST_PATH_IMAGE041
、
Figure 581720DEST_PATH_IMAGE042
、
Figure 234419DEST_PATH_IMAGE043
(where x =0.75y and 0.60)<y<0.75）、
Figure 682849DEST_PATH_IMAGE044
、
Figure 839024DEST_PATH_IMAGE045
(wherein 0)<x<0.25 ) and combinations thereof. In one variation, the one or more oxide-based materials can have a thickness of greater than or equal to about
Figure 432816DEST_PATH_IMAGE046
To less than or equal to about
Figure 323543DEST_PATH_IMAGE047
The ionic conductivity of (a).
As an embodiment, the sulfide solid state electrolyte may include one or more sulfide-based materials selected from the group consisting of:
Figure 231456DEST_PATH_IMAGE048
、
Figure 773296DEST_PATH_IMAGE049
(wherein M is Si, ge or Sn and 0. Ltoreq. X.ltoreq.2),
Figure 272410DEST_PATH_IMAGE050
、
Figure 899700DEST_PATH_IMAGE051
、
Figure 890266DEST_PATH_IMAGE052
、
Figure 286612DEST_PATH_IMAGE053
、
Figure 487786DEST_PATH_IMAGE054
、
Figure 681001DEST_PATH_IMAGE055
、
Figure 196296DEST_PATH_IMAGE056
、
Figure 994619DEST_PATH_IMAGE057
、
Figure 101115DEST_PATH_IMAGE058
、
Figure 702998DEST_PATH_IMAGE059
、
Figure 38296DEST_PATH_IMAGE060
、
Figure 409234DEST_PATH_IMAGE061
(wherein X is Cl, br or I),
Figure 624315DEST_PATH_IMAGE062
、
Figure 447914DEST_PATH_IMAGE063
、
Figure 836170DEST_PATH_IMAGE064
、
Figure 809418DEST_PATH_IMAGE065
、
Figure 992138DEST_PATH_IMAGE066
、
Figure 834192DEST_PATH_IMAGE067
、
Figure 760559DEST_PATH_IMAGE068
(wherein 0.5. Ltoreq. X. Ltoreq.0.7) and combinations thereof. In one variation, the one or more sulfide-based materials can have a composition of greater than or equal to about
Figure 325664DEST_PATH_IMAGE069
To an ionic conductivity of less than or equal to about 1S/cm.
As an embodiment, the halide solid state electrolyte may include one or more halide based materials selected from the group consisting of:
Figure 741602DEST_PATH_IMAGE070
、
Figure 274214DEST_PATH_IMAGE071
、
Figure 551743DEST_PATH_IMAGE072
、
Figure 486201DEST_PATH_IMAGE073
、
Figure 276302DEST_PATH_IMAGE074
、
Figure 312523DEST_PATH_IMAGE075
、
Figure 315114DEST_PATH_IMAGE076
、
Figure 900816DEST_PATH_IMAGE077
(wherein 0)<x<1) And combinations thereof. In one variation, the one or more halide-based materials can have a composition of greater than or equal to about
Figure 406359DEST_PATH_IMAGE078
To less than or equal to about
Figure 116826DEST_PATH_IMAGE079
The ionic conductivity of (a).
As an embodiment, the boride solid electrolyte may include one or more borate-based materials selected from the group consisting of:
Figure 188687DEST_PATH_IMAGE080
、
Figure 363317DEST_PATH_IMAGE081
and combinations thereof. In one variation, the one or more borate-based materials may have a value of greater than or equal to about
Figure 245953DEST_PATH_IMAGE082
To less than or equal to about
Figure 506033DEST_PATH_IMAGE083
The ionic conductivity of (2).
As an implementation sideThe nitride solid state electrolyte may include one or more nitride-based materials selected from the group consisting of:
Figure 116006DEST_PATH_IMAGE084
、
Figure 427033DEST_PATH_IMAGE085
、
Figure 464259DEST_PATH_IMAGE086
and combinations thereof. In one variation, the one or more nitride-based materials can have a thickness of greater than or equal to about
Figure 211635DEST_PATH_IMAGE087
To an ionic conductivity of less than or equal to about 1S/cm.
As an embodiment, the hydride solid-state electrolyte may include one or more hydride-based materials selected from the group consisting of:
Figure 828561DEST_PATH_IMAGE088
、
Figure 712204DEST_PATH_IMAGE089
、
Figure 467801DEST_PATH_IMAGE090
(wherein X is one of Cl, br and I),
Figure 968053DEST_PATH_IMAGE091
、
Figure 464369DEST_PATH_IMAGE092
、
Figure 468097DEST_PATH_IMAGE093
And combinations thereof. In one variation, the one or more hydride-based materials can have a thickness of greater than or equal to about
Figure 738803DEST_PATH_IMAGE094
To less than or equal to about
Figure 70559DEST_PATH_IMAGE095
The ionic conductivity of (a).
As an embodiment, the solid electrolyte particles may be a quasi-solid electrolyte comprising a mixture of the non-aqueous liquid electrolyte solution and the solid electrolyte system detailed above, for example, comprising one or more ionic liquids and one or more metal oxide particles (such as, for example, alumina: (a)
Figure 826025DEST_PATH_IMAGE096
) And/or silica (a)
Figure 684260DEST_PATH_IMAGE097
））。
In the present embodiment, the particle size of the ceramic powder is less than 1 μm; preferably, the particle size of the ceramic powder is less than 500nm, such as 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm and the like; further preferably, the particle diameter of the ceramic powder is smaller than the pore diameter of the pore structure.
In the examples of the present application, suitable lithium salts generally have an inert anion, as a preferred embodiment. A non-limiting list of lithium salts that can be dissolved in an organic solvent or mixture of organic solvents to form a non-aqueous liquid electrolyte solution includes: lithium hexafluorophosphate (
Figure 778730DEST_PATH_IMAGE098
) Lithium perchlorate (II)
Figure 253574DEST_PATH_IMAGE099
) Lithium aluminum tetrachloride (
Figure 360201DEST_PATH_IMAGE100
) Lithium iodide (LiI), lithium bromide (LiBr) lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiSCN)
Figure 354833DEST_PATH_IMAGE101
) Lithium difluorooxalato borate (a)
Figure 872402DEST_PATH_IMAGE102
) (LiODFB), lithium tetraphenylborate (B)
Figure 303383DEST_PATH_IMAGE103
) Bis (oxalic acid) lithium borate (b)
Figure 151385DEST_PATH_IMAGE104
) (LiBOB), lithium tetrafluoro-oxalato-phosphate: (
Figure 718632DEST_PATH_IMAGE105
) (LiFOP), lithium nitrate (C)
Figure 875944DEST_PATH_IMAGE106
) Lithium hexafluoroarsenate (
Figure 59801DEST_PATH_IMAGE107
) Lithium trifluoromethanesulfonate (A), (B), (C)
Figure 442984DEST_PATH_IMAGE108
) Bis (trifluoromethanesulfonylimide) Lithium (LITFSI) (II)
Figure 130318DEST_PATH_IMAGE109
) Lithium bis (fluorosulfonyl) imide(s) (iii)
Figure 458531DEST_PATH_IMAGE110
) (LIFSI) and combinations thereof. In certain variations, the lithium salt is selected from lithium hexafluorophosphate: (ii)
Figure 801787DEST_PATH_IMAGE111
) Bis (trifluoromethanesulfonylimide) Lithium (LiTFSI) ((LiTFSI))
Figure 506438DEST_PATH_IMAGE112
) Lithium bis (fluorosulfonylimide) ((ii))
Figure 799010DEST_PATH_IMAGE113
) (LiFSI), lithium fluoroalkylphosphonate (LiFAP), lithium phosphate (LiFAP)
Figure 298125DEST_PATH_IMAGE114
) And combinations thereof.
As a preferred embodiment, in the examples of the present application, the composition of the organic solid electrolyte layer includes, in terms of mass percent:
30-60wt% of polymer solid electrolyte, 1-10wt% of first and second ionic liquids, 15-30wt% of lithium salt, 10-30wt% of succinonitrile and 10-30wt% of ceramic electrolyte powder.
Specifically, the content of each component in the organic solid electrolyte layer may be adjusted according to factors such as the use condition of the battery, design, and actual formulation system. In specific implementation, the polymer solid electrolyte, the lithium salt, the first and second ionic liquids, the succinonitrile and the ceramic powder are prepared according to the proportion so as to be used in the subsequent preparation process.
Optionally, the mass ratio of the lithium salt is not particularly limited, and the lithium salt mainly functions to improve the ionic conductivity of the composite electrolyte, and may be 20%, 25%, 30%, 35%, 40%, 45%, 50%, or the like, and preferably 20% without departing from the inventive concept of the present application.
Alternatively, the mass ratio of succinonitrile may be 10%, 15%, 20%, 25%, 30%, etc., and preferably, the mass ratio of succinonitrile is 15 to 25wt%.
Alternatively, the mass ratio of the ceramic powder may be 10%, 12.5%, 15%, 17.5%, 20%, 22.5%, 25%, 30%, or the like.
In the application, the pore structure prepared by the succinonitrile pore-forming effect is in a nanometer scale, so that the first ionic liquid can be uniformly dispersed in the pore structure of the organic solid electrolyte layer; if the pore structure is too large in size, the ionic liquid is agglomerated and formed in the pore structure, the dispersion is not uniform, and the retention effect of the pore structure on the ionic liquid is small, so that the ionic liquid is not favorably retained in the composite electrolyte.
In response to the above-mentioned composite electrolyte, the present application provides a method for preparing a composite electrolyte, the method comprising:
s1, dispersing a polymer solid electrolyte, a first ionic liquid and a lithium salt into a first solvent according to a preset proportion, and mixing to obtain a first mixture;
s2, adding succinonitrile with preset mass into the first mixture, and mixing to obtain a second mixture;
s3, drying the second mixture and preparing a film to obtain a polymer solid electrolyte film;
s4, soaking the polymer solid electrolyte membrane in a second ionic liquid to obtain an organic solid electrolyte layer, wherein the organic solid electrolyte layer comprises a pore structure with the pore diameter smaller than 100 nm;
s5, dissolving sulfide solid electrolyte and a binder in a second solvent to form solid electrolyte slurry, coating the solid electrolyte slurry on a release film, and drying to obtain an inorganic solid electrolyte layer;
and S6, laminating the organic solid electrolyte layer on two sides of the inorganic solid electrolyte layer to form a composite electrolyte, wherein the first ionic liquid is dispersed in the pore structure, at least part of the second ionic liquid is positioned on the interface of the inorganic solid electrolyte layer and the organic solid electrolyte layer, and the mutual dissolving performance of the first ionic liquid and the polymer solid electrolyte is superior to that of the second ionic liquid and the polymer solid electrolyte.
Preferably, 30-60wt% of polymer solid electrolyte, first ionic liquid and 15-30wt% of lithium salt are dissolved in a first solvent, and are magnetically stirred at room temperature for 12 hours to obtain a first mixture; adding succinonitrile with preset mass into the first mixture, and magnetically stirring for 8-12h at 50 ℃ to obtain a second mixture; placing the second mixture into a preset mold, drying at room temperature for 12 hours, and drying again at 60 ℃ for 12 hours to obtain a porous polymer solid electrolyte membrane; and (3) soaking the polymer solid electrolyte membrane in a second ionic liquid for 12-20h to obtain the organic solid electrolyte layer.
It can be understood that the content of the ionic liquid in the finally prepared composite electrolyte should be the sum of the contents of the first ionic liquid and the second ionic liquid, and the sum of the contents of the first ionic liquid and the second ionic liquid should satisfy 1-10wt%.
In the examples of the present application, the first solvent and the second solvent are not particularly limited, and any known organic solvent may be used as the first solvent and the second solvent in the present application without departing from the inventive concept of the present application. Preferably, the first solvent and the second solvent are both N, N-Dimethylformamide (DMF), and the mass ratio of the first solvent to the polymer solid electrolyte is preferably 3-5.
It should be noted that, in the embodiment of the present application, specific adding quality of the ceramic powder is not limited, and a user may set the adding quality according to actual requirements on the premise of not violating the inventive concept of the present application.
Specifically, the preset mold comprises but is not limited to a polytetrafluoroethylene mold, the second mixture is placed in the polytetrafluoroethylene mold to be dried at room temperature, the mixture is dried again at 60-80 ℃ for 10-24h to obtain a porous electrolyte membrane, and then the porous electrolyte membrane is immersed in the ionic liquid for 12-20h to obtain the jelly-like composite electrolyte.
The application has no particular requirements for the drying process. Any known drying process can be used in the present application without departing from the inventive concept of the present application. By way of illustrative example only, and not by way of any limitation as to scope of protection, the drying process may be performed by baking or the like. It is understood that the relevant process parameters such as the drying temperature, the drying time and the like are not particularly limited, and any technical scheme obtained by adjusting the parameters without creative work is within the protection scope of the present application on the basis of not departing from the inventive concept of the present application.
In the embodiment of the application, in the crystallization process, the hole forming process of the succinonitrile on the polymer solid electrolyte is uniform, and a pinhole-shaped porous structure is formed. Meanwhile, the second ionic liquid can be better compounded with the nanopore structure in a mode of soaking the second ionic liquid in the polymer solid electrolyte membrane, and cannot seep out when being matched with the compounding of the second ionic liquid and the battery.
It should be noted that, in the examples of the present application, the binder used in the process of preparing the inorganic solid electrolyte layer and the content thereof are not particularly limited, and any known binder may be used as the binder in the examples of the present application without departing from the inventive concept of the present application, for example, the binder may be one or more of polytetrafluoroethylene, styrene-butadiene rubber, hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose, hydroxyethyl cellulose, and polyvinyl alcohol. Meanwhile, the specific dosage of the binder can be matched according to the implementation requirement.
Corresponding to above-mentioned compound electrolyte, this application still provides a lithium ion battery, lithium ion battery includes positive pole piece, negative pole piece and above-mentioned compound electrolyte, the negative pole piece is the lithium metal negative pole.
The negative electrode sheet according to the present invention may be a lithium foil, or may be composed of a current collector and a negative electrode active material containing metallic lithium.
Alternatively, the lithium foil may be lithium metal or a lithium alloy; preferably, the lithium alloy may be one of an aluminum lithium alloy, a lithium tin alloy, a lithium lead alloy, and a lithium silicon alloy.
As an alternative to the negative electrode sheet, the current collector and the negative active material containing metallic lithium may be a conventional negative electrode in the prior art; the current collector may be a copper foil, and the negative active material may be lithium metal or a lithium alloy, preferably, the lithium alloy may be one of an aluminum lithium alloy, a lithium tin alloy, a lithium lead alloy, and a lithium silicon alloy.
Preferably, the anode active material may form an active material layer by combining with an anode binder, and the anode binder may be one or more of polytetrafluoroethylene, styrene butadiene rubber, hydroxypropylmethylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, and polyvinyl alcohol. The amount of the anode binder may be used in a conventional amount thereof. The negative electrode binder may be used in an amount of 2 to 50 parts by weight with respect to 100 parts by weight of the negative electrode active material.
As a preferred embodiment, in the present application example, the positive electrode sheet includes a positive electrode current collector, a positive electrode active material layer, and the positive electrode current collector may be a metal foil, a metal mesh or gauze, or a mesh-shaped metal containing aluminum or any other suitable conductive material known to those skilled in the art.
As a preferred embodiment, in the examples of the present application, the positive electrode sheet is formed of a plurality of positive electrode active particles containing one or more transition metal cations, such as manganese (Mn), nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), vanadium (V), and combinations thereof. In some embodiments, the positive electrode active material layer further includes an electrolyte, such as a plurality of electrolyte particles.
The positive active material includes one of a layered oxide cathode, a spinel cathode, and a polyanion cathode. For example, a layered oxide cathode (e.g., a rock salt layered oxide) comprises one or more lithium-based positive electrode active materials selected from the group consisting of:
Figure 925415DEST_PATH_IMAGE115
，
Figure 450069DEST_PATH_IMAGE116
(wherein x is more than or equal to 0 and less than or equal to 1 and y is more than or equal to 0 and less than or equal to 1),
Figure 315257DEST_PATH_IMAGE117
(wherein x is more than or equal to 0 and less than or equal to 1 and y is more than or equal to 0 and less than or equal to 1),
Figure 985272DEST_PATH_IMAGE118
(wherein 0. Ltoreq. X. Ltoreq.1), and
Figure 178487DEST_PATH_IMAGE119
(where M is one of Mn, ni, co and Al, and x is 0. Ltoreq. X.ltoreq.1).
In a particular embodiment, one or more lithium-based positive electrode active materials may optionally be coated and/or may be doped. Further, in certain embodiments, one or more lithium-based positive electrode active materials may optionally be mixed with one or more conductive materials that provide an electron conduction path and/or at least one polymeric binder material that improves the structural integrity of the positive electrode. For example, the positive electrode active material layer may include greater than or equal to about 30wt% to less than or equal to about 98wt% of one or more lithium-based positive electrode active materials; greater than or equal to about 0wt% to less than or equal to about 30wt% of a conductive material; and greater than or equal to about 0wt% to less than or equal to about 20wt% binder, and in certain aspects, optionally greater than or equal to about 1wt% to less than or equal to about 20wt% binder.
As a preferred embodiment, in the examples of the present application, the positive electrode active material layer may be optionally mixed with a positive electrode binder as follows: such as Polytetrafluoroethylene (PTFE), sodium carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile Butadiene Rubber (NBR), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, lithium alginate, and combinations thereof.
In one preferred embodiment, the conductive material may include a carbon-based material, powdered nickel or other metal particles, or a conductive polymer. The carbon-based material may include particles such as carbon black, graphite, acetylene black (e.g., KETCHEN black or DENKATM black), carbon fibers and nanotubes, graphene, and the like. Examples of the conductive polymer include polyaniline, polythiophene, polyacetylene, polypyrrole, and the like.
Example 1
The embodiment of the application provides a composite electrolyte, which comprises the following preparation processes:
preparation of organic solid electrolyte layer:
dispersing 50wt% of polyethylene oxide (PEO), 8wt% of a first ionic liquid and 20wt% of a lithium salt into an organic solvent, and magnetically stirring at room temperature for 12 hours to obtain a first mixture, wherein the first ionic liquid is 1-butyl-3-methylimidazolium chloride, the lithium salt is LiTFSI, the organic solvent is N, N-dimethylformamide (NMP), and the mass ratio of the organic solvent to the polyethylene oxide is 5;
adding 20wt% of succinonitrile to the first mixture, and magnetically stirring at 50 ℃ for 8-12h to obtain a second mixture;
placing the second mixture into a polytetrafluoroethylene mold, drying at room temperature for 12 hours, and drying again at 60 ℃ for 12 hours to obtain a polymer solid electrolyte membrane which is a porous electrolyte membrane;
and soaking the polymer solid electrolyte membrane in 2wt% of second ionic liquid for 12 hours to obtain the organic solid electrolyte layer, wherein the second ionic liquid is methyl propyl piperidine bis (trifluoromethyl sulfonyl) imine.
Preparation of inorganic solid electrolyte layer:
mixing sulfide solid electrolyte powder Li 6 PS 5 Cl, binder PTFE and a second solvent N, N-dimethylformamide to form a solid electrolyte slurry, wherein Li 6 PS 5 The mass ratio of Cl to PTFE is 90;
uniformly coating the solid electrolyte slurry on a PET film, and drying the solid electrolyte slurry coated on the PET film at a set drying temperature to evaporate a second solvent to obtain an electrolyte film;
and taking the electrolyte film from the PET film, cutting and drying to obtain a compact sulfide lithium ion conductor electrolyte sheet (namely an inorganic solid electrolyte layer).
Laminating:
and respectively laminating the organic solid electrolyte layers on two sides of the inorganic solid electrolyte layer through lamination sheets to obtain the composite electrolyte.
Example 2
The difference from example 1 is that in the organic solid electrolyte layer, the polymer solid electrolyte was polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP).
Example 3
The difference compared to example 1 is that in the organic solid electrolyte layer, the polymer solid electrolyte is polymethyl methacrylate (PMMA).
Example 4
Compared with the example 1, the difference is that the mass ratio of the first ionic liquid to the second ionic liquid is 3.
Example 5
Compared with example 1, the difference is that the mass ratio of the first ionic liquid to the second ionic liquid is 1.
Comparative example 1
Compared with the embodiment 1, the difference is that in the preparation process of the organic solid electrolyte layer, the types of the first ionic liquid and the second ionic liquid are the same, and are both methyl propyl piperidine bi (trifluoromethyl sulfonyl) imine.
Comparative example 2
Compared with the embodiment 1, the difference is that in the preparation process of the organic solid electrolyte layer, the types of the first ionic liquid and the second ionic liquid are the same, and the ionic liquids are all chlorinated 1-butyl-3-methylimidazolium salt.
Preparation of the Battery
Laminating the positive electrode, negative electrode and the composite electrolyte prepared in the above examples and comparative examples to prepare a lithium ion battery, wherein the composition of the positive electrode is 95wt% NCM523, 2wt% super-P, 3wt% PVDF, the composition of the negative electrode is 94 wt% graphite, 2wt% super-P, 2wt% SBR, 2wt% CMC.
1. 500 cycles of the cycle performance test method.
The lithium ion batteries obtained in the above examples and comparative examples were subjected to cycle performance tests, the procedure was as follows: the testing temperature is 25 +/-2 ℃; (1) charging to the final voltage at 1C or specified current, cutting off current at 0.05C, and standing for 30min; (2) discharging at 1C to discharge final voltage (2.75V), recording discharge capacity, and standing for 30min; and (5) circularly executing the steps (1) to (2) until the circulation is 500 circles, and recording the final capacity retention rate.
Capacity retention rate of cell circulating 500 circles
Example 1 95.1%
Example 2 95.4%
Example 3 93.8%
Example 4 94.9%
Example 5 94.2%
Comparative example 1 94.2%
Comparative example 2 92.9%
According to the experimental data, the lithium ion battery prepared by the scheme of the application has the advantage that the cycle performance of the battery is effectively improved.
From the cycle data of the battery, the succinonitrile forms a positive pore-forming effect on the polymer solid electrolyte, uniformly dispersed nanopores are formed in the polymer solid electrolyte membrane, the first ionic liquid with better mutual solubility with the polymer solid electrolyte is used for mutually dissolving with the polymer solid electrolyte, so that the ionic liquid is dispersed in the nanopores and uniformly dispersed in the solid electrolyte, the polymer solid electrolyte membrane prepared by soaking the polymer solid electrolyte membrane with the second ionic liquid with poorer mutual solubility with the polymer solid electrolyte is used, so that the second ionic liquid is positioned on the interface of the inorganic solid electrolyte layer and the organic solid electrolyte layer, lithium ion transmission is promoted, and the overall cycle performance of the battery is effectively improved.
By comparing example 1 with examples 4 to 5, it is suspected that the possible reason is that the second ionic liquid with poor solubility cannot form a stable relationship at the interface of the organic and inorganic solid electrolyte layers due to the failure to form an effective pore structure when the amount of the first ionic liquid is insufficient, thereby affecting the cycle performance.
In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, the meaning of "a plurality" is two or more unless otherwise specified.
The above description is only a preferred embodiment of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like that are made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (8)

1. A composite electrolyte is characterized by at least comprising an inorganic solid electrolyte layer and organic solid electrolyte layers arranged on two sides of the inorganic solid electrolyte layer;
the organic solid electrolyte layer comprises a pore structure with a pore diameter of less than 100 nm;
the components of the organic solid electrolyte layer comprise a polymer solid electrolyte, a lithium salt, a first ionic liquid, a second ionic liquid and succinonitrile;
the inorganic solid electrolyte layer has a composition including at least a sulfide solid electrolyte;
the first ionic liquid is dispersed in the pore structure, and the second ionic liquid is at least partially positioned on the interface of the inorganic solid electrolyte layer and the organic solid electrolyte layer;
the mutual dissolving performance of the first ionic liquid and the polymer solid electrolyte is better than that of the second ionic liquid and the polymer solid electrolyte.
2. The composite electrolyte according to claim 1, wherein the first ionic liquid comprises an imidazole-based ionic liquid and the second ionic liquid comprises a piperidine-based ionic liquid.
3. A composite electrolyte according to claim 1, wherein the polymer solid-state electrolyte comprises a crystalline polymer.
4. A composite electrolyte according to claim 1, wherein the polymer solid electrolyte is capable of forming a porous structure under the action of succinonitrile.
5. The composite electrolyte of claim 1, wherein the organic solid electrolyte layer further comprises a ceramic powder.
6. The composite electrolyte of claim 1, wherein the lithium salt comprises one or more of lithium bis (trifluoromethylsulfonate) imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, and lithium bis (fluorosulfonamide).
7. A production method for producing the composite electrolyte according to any one of claims 1 to 6, characterized by comprising:
dispersing a polymer solid electrolyte, a first ionic liquid and a lithium salt into a first solvent according to a preset proportion, and mixing to obtain a first mixture;
adding succinonitrile with preset mass into the first mixture, and mixing to obtain a second mixture;
drying the second mixture and preparing a film to obtain a polymer solid electrolyte film;
soaking the polymer solid electrolyte membrane in a second ionic liquid to obtain an organic solid electrolyte layer, wherein the organic solid electrolyte layer comprises a pore structure with the pore diameter of less than 100 nm;
dissolving a sulfide solid electrolyte and a binder in a second solvent to form solid electrolyte slurry, coating the solid electrolyte slurry on a release film, and drying to obtain an inorganic solid electrolyte layer;
and laminating the organic solid electrolyte layer on two sides of the inorganic solid electrolyte layer to form a composite electrolyte, wherein the first ionic liquid is dispersed in the pore structure, at least part of the second ionic liquid is positioned on the interface of the inorganic solid electrolyte layer and the organic solid electrolyte layer, and the mutual dissolving performance of the first ionic liquid and the polymer solid electrolyte is better than that of the second ionic liquid and the polymer solid electrolyte.
8. A lithium ion battery, characterized in that the lithium ion battery comprises a positive pole piece, a negative pole piece and the composite electrolyte of any one of claims 1 to 6.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020091448A1 (en) * 2018-10-31 2020-05-07 주식회사 엘지화학 Lithium secondary battery
CN111269509A (en) * 2020-02-14 2020-06-12 中国科学院长春应用化学研究所 Porous plastic crystal electrolyte for all-solid-state metal-air battery, preparation method of porous plastic crystal electrolyte and all-solid-state metal-air battery
CN113381065A (en) * 2021-05-21 2021-09-10 万向一二三股份公司 Polymer composite solid electrolyte and preparation method and application thereof
CN114204118A (en) * 2021-12-15 2022-03-18 武汉理工大学 PVDF (polyvinylidene fluoride) -based composite solid electrolyte and preparation method thereof
CN114784372A (en) * 2022-05-24 2022-07-22 苏州清陶新能源科技有限公司 Preparation method of composite solid electrolyte

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2686890C (en) * 2007-05-11 2015-10-20 National Research Council Of Canada Plastic crystal electrolyte with a broad potential window

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020091448A1 (en) * 2018-10-31 2020-05-07 주식회사 엘지화학 Lithium secondary battery
CN111269509A (en) * 2020-02-14 2020-06-12 中国科学院长春应用化学研究所 Porous plastic crystal electrolyte for all-solid-state metal-air battery, preparation method of porous plastic crystal electrolyte and all-solid-state metal-air battery
CN113381065A (en) * 2021-05-21 2021-09-10 万向一二三股份公司 Polymer composite solid electrolyte and preparation method and application thereof
CN114204118A (en) * 2021-12-15 2022-03-18 武汉理工大学 PVDF (polyvinylidene fluoride) -based composite solid electrolyte and preparation method thereof
CN114784372A (en) * 2022-05-24 2022-07-22 苏州清陶新能源科技有限公司 Preparation method of composite solid electrolyte

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Sanwich-like poly(propylene carbonate)-Based Electrolyte for Ambient-Temperature Solid-State Lithium Ion Batteries;Hongyun Yue 等;《ACS Sustainable Chem. Eng.》;20171122;268-274 *

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