CN115312892A - Electrochemical device and electronic apparatus - Google Patents
Electrochemical device and electronic apparatus Download PDFInfo
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- CN115312892A CN115312892A CN202211234912.6A CN202211234912A CN115312892A CN 115312892 A CN115312892 A CN 115312892A CN 202211234912 A CN202211234912 A CN 202211234912A CN 115312892 A CN115312892 A CN 115312892A
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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
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- H—ELECTRICITY
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- H01M10/05—Accumulators with non-aqueous electrolyte
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- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
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Abstract
The application discloses an electrochemical device and an electronic apparatus. The electrochemical device comprises a positive plate, a negative plate, electrolyte and an isolating membrane, wherein the isolating membrane is arranged between the positive plate and the negative plate; wherein, along the width direction of the positive plate, the length of the isolating film exceeding the positive plate is a mm, the thickness of the isolating film is b mu m, and b/a is more than or equal to 0.4 and less than or equal to 30; the positive plate comprises a positive active material layer, the negative plate comprises a negative active material layer, at least one of the positive active material layer, the negative active material layer and the electrolyte comprises a fluorine additive, the fluorine additive is selected from at least one of substances with a molecular formula shown as formula AxDF6, wherein A is selected from one of lithium, sodium, potassium, magnesium and calcium, D is selected from one of germanium, tin, selenium, silicon, antimony, arsenic and aluminum, and the value range of x is more than or equal to 1 and less than or equal to 3. The electrochemical device of the present application has good thermal safety performance.
Description
Technical Field
The present disclosure relates to the field of electrochemistry, and more particularly, to an electrochemical device and an electronic apparatus.
Background
With the development of electronic devices and electric vehicles, people put higher demands on electrochemical devices, which are key elements for energy storage, such as the improvement of energy density of electrochemical devices, the enhancement of safety performance, the enhancement of quick charging capability and the like. The safety performance of the electrochemical device comprises a thermal shock performance test, the thermal shock performance generally needs to be stored in a box body at 130 ℃ for a long time under the full-power condition, and one of the reasons that the electrochemical device is difficult to meet the thermal shock performance is short-circuit failure of the electrochemical device caused by thermal shrinkage of an isolating membrane.
Disclosure of Invention
The embodiment of the application provides an electrochemical device and electronic equipment, and the problem that the electrochemical device is short-circuited due to thermal shrinkage failure can be solved.
In a first aspect, the present application provides an electrochemical device comprising a positive plate, a negative plate, an electrolyte and an isolation film, wherein the isolation film is arranged between the positive plate and the negative plate;
wherein, along the width direction of the positive plate, the length of the isolating film exceeding the positive plate is a mm, the thickness of the isolating film is b μm, and b/a is more than or equal to 0.4 and less than or equal to 30; the positive plate comprises a positive active material layer, the negative plate comprises a negative active material layer, at least one of the positive active material layer, the negative active material layer and the electrolyte comprises a fluorine additive, and the fluorine additive is selected from at least one of substances with a molecular formula shown in a formula I;
the AxDF6 has the formula I,
wherein A is selected from one of lithium, sodium, potassium, magnesium and calcium, D is selected from one of germanium, tin, selenium, silicon, antimony, arsenic and aluminum, and the value range of x is more than or equal to 1 and less than or equal to 3.
In some exemplary embodiments, the fluorine-based additive is selected from at least one of the following:
(1) Lithium hexafluorogermanate and potassium hexafluorogermanate;
(2) Lithium hexafluorostannate;
(3) Lithium hexafluoroselenate;
(4) Lithium hexafluorosilicate, sodium hexafluorosilicate, calcium hexafluorosilicate, magnesium hexafluorosilicate, potassium hexafluorosilicate;
(5) Lithium hexafluoroantimonate, sodium hexafluoroantimonate, potassium hexafluoroantimonate;
(6) Potassium hexafluoroarsenate, sodium hexafluoroarsenate;
(7) Lithium hexafluoroaluminate, sodium hexafluoroaluminate and potassium hexafluoroaluminate.
In some exemplary embodiments, the electrochemical device satisfies at least one of the following conditions:
condition i: the range of the length a of the isolating film beyond the positive plate is more than or equal to 0.5 and less than or equal to 9;
condition ii: the thickness b mm of the isolating membrane ranges from 3 to 16;
condition iii: a and b satisfy the relation: b/a is more than or equal to 0.8 and less than or equal to 10.
In some exemplary embodiments, the separator is one of a polypropylene film and a polyethylene film.
In some exemplary embodiments, the positive electrode active material layer includes a fluorine-based additive in an amount of X by mass in the positive electrode active material layer 1 And X is more than or equal to 0.0001 percent 1 Less than or equal to 3.0 percent; and/or the presence of a gas in the atmosphere,
the negative electrode active material layer comprises a fluorine additive, and the mass percentage of the fluorine additive in the negative electrode active material layer is X 2 And X is more than or equal to 0.0001% 2 ≤3.0%。
In some exemplary embodiments, the electrolyte comprises a fluorine additive, and the mass percentage of the fluorine additive in the electrolyte is Y, and Y is more than or equal to 0.01% and less than or equal to 8.0%.
In some exemplary embodiments, the electrolyte further includes a first additive selected from at least one of 1,3-propane sultone and a polynitrile compound.
In some exemplary embodiments, the polynitrile compound comprises at least one of a dinitrile or a dinitrile;
the dinitrile comprises one of succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, 1,5-dicyanopentane, 1,6-dicyanohexane, tetramethyl succinonitrile, ethylene glycol bis (propionitrile) ether;
the trinitrile comprises one of 1,3,5-pentanetrimethylnitrile, 1,2,3-propanetrimethylnitrile, 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbonitrile, 1,2,3-tris (2-cyanoethoxy) propane.
In some exemplary embodiments, the mass percentage of the first additive in the electrolyte is Z, and Z is more than or equal to 0.5% and less than or equal to 10%.
In some exemplary embodiments, Y, Z satisfies the relationship: Y/Z is more than or equal to 0.002 and less than or equal to 4.
In a second aspect, the present application provides an electronic device comprising an electrochemical device as described above.
Based on electrochemical device and electronic equipment of this application embodiment, through setting up that at least one in positive pole active material layer, negative pole active material layer and the electrolyte includes fluorine type additive, fluorine type additive can decompose at the surface of positive plate and negative pole piece to participate in forming the protective layer that contains metallic element, this protective layer can suppress metallic element's dissolving out and deposit to a certain extent, promotes the content of inorganic matter in positive plate and negative pole piece surface protective layer simultaneously, reduces the rise of electrochemical device internal temperature under the high temperature abuse, reduces the barrier film and contracts. This application still sets up the edge the width direction of positive plate, the barrier film surpasss the length of positive plate to two parameters of the length that surpass the positive plate to the barrier film and the thickness of barrier film are injectd, and collocation fluorine class additive makes the barrier film be in the difficult transition shrink of high temperature thermal environment, prevents positive plate and negative pole piece short circuit, improves electrochemical device's thermal safety performance jointly.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic view of the structure of the position of a positive plate relative to a negative plate along the width direction of the positive plate in the related art.
Fig. 2 is a schematic structural view of the separator exceeding the positive electrode sheet in the width direction of the positive electrode sheet in one embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
The inventor finds that the isolating membrane arranged between the positive plate and the negative plate is easy to shrink when being heated, and the contact short circuit between the positive plate and the negative plate is easy to cause the failure of the electrochemical device. The inventors have also found that, as shown in fig. 1, the negative electrode tab 200' has a negative electrode edge portion 201' for connecting the negative electrode tab, and the positive electrode tab 100' has a positive electrode edge portion 101' for connecting the positive electrode tab, and in the related art, the negative electrode edge portion 201' of the negative electrode tab 200' protrudes beyond the positive electrode edge portion 101' of the positive electrode tab 100', and when the separator 300' provided between the positive electrode tab 100' and the negative electrode tab 200' shrinks, it is particularly easy to cause short-circuiting of the positive electrode edge portion 101' and portions in the vicinity of the positive electrode edge portion 101' of the positive electrode tab 100' with the negative electrode tab 200 '. Based on this, the embodiment of the application provides an electrochemical device and electronic equipment.
The isolating membrane is easy to shrink when being heated, and the anode plate and the cathode plate are in contact short circuit, so that the electrochemical device fails, particularly the position below the pole lug is easy to short circuit due to thermal shrinkage. The fluorine additive used in the application can be decomposed on the interface of the positive plate and the negative plate, and a protective layer containing metal elements is formed, the protective layer can inhibit the dissolution and deposition of the metal elements to a certain degree, meanwhile, the content of inorganic matters in the interface film of the positive plate and the negative plate is improved, and the rise of the internal temperature of the electrochemical device under high-temperature abuse is reduced, so that the shrinkage of the isolation film is reduced. The shrinkage of the diaphragm is not only influenced by the temperature, but also the thickness of the diaphragm per se has certain influence on the shrinkage degree, the length of the isolation film below the lug exceeding the positive plate is limited by the relationship with the thickness of the isolation film, and meanwhile, the fluorine additive is matched to ensure the thermal safety performance of the electrochemical device together.
As shown in fig. 2, the electrochemical device provided in the embodiment of the present application includes a positive electrode sheet 100, a negative electrode sheet 200, a positive electrode tab, a negative electrode tab, and a separator 300, the positive electrode sheet 100 having a positive electrode edge portion 101 along a width direction of the positive electrode sheet, and the negative electrode sheet 200 having a negative electrode edge portion 201 along a width direction of the negative electrode sheet. The separator 300 is disposed between the positive electrode sheet 100 and the negative electrode sheet 200, and the three are sequentially stacked or wound, and the positive electrode edge 101 and the negative electrode edge 201 are connected to the positive electrode tab and the negative electrode tab, respectively, to form an electrode assembly. The electrochemical device further comprises electrolyte and an outer package, the electrode assembly is arranged in the inner space of the outer package, the positive electrode tab and the negative electrode tab are led out to the outer space of the outer package, the positive electrode tab and the negative electrode tab are electrically connected with an external circuit, the electrolyte is injected into the inner space of the outer package, and the battery chemical device is manufactured after the outer package is sealed.
As shown in fig. 2, the separator 300 and the negative electrode edge portion 201 both extend beyond the positive electrode edge portion 101 in the width direction of the positive electrode sheet. Of course, besides the positive electrode edge 101, the separator 300 may also extend out of other edge portions of the positive electrode sheet 100, for example, when the positive electrode sheet 100 is unfolded to be rectangular, the rectangular positive electrode sheet 100 has four edge portions, one of which forms the positive electrode edge 101, and at this time, the separator 300 may also extend out of at least one of the other three edge portions of the positive electrode sheet 100 along the width or length direction of the positive electrode sheet, so as to reduce the occurrence of short circuit between the positive electrode sheet 100 and the negative electrode sheet 200 when the separator 300 is thermally shrunk.
As shown in fig. 2, the length of the separator 300 beyond the positive electrode edge portion 101 in the width direction of the positive electrode sheet is a mm, the thickness of the separator 300 is b μm, and a and b satisfy the conditional expression: b/a is more than or equal to 0.4 and less than or equal to 30, and the occurrence of short circuit caused by contact of the positive plate 100 and the negative plate 200 due to thermal shrinkage of the isolating membrane 300 can be effectively reduced within the range of the conditional expression. Preferably, a and b satisfy the relation: b/a is more than or equal to 0.8 and less than or equal to 10.
The positive electrode sheet 100 comprises a positive current collector 120 and a positive active material layer 110 arranged on the surface of the positive current collector 120, and the negative electrode sheet 200 comprises a negative current collector 220 and a negative active material layer 210 arranged on the surface of the negative current collector 220, wherein at least one of the positive active material layer 110, the negative active material layer 210 and the electrolyte comprises a fluorine-based additive, and the fluorine-based additive is at least one selected from substances with a molecular formula shown in formula I;
the AxDF6 has the formula I,
wherein A is selected from one of lithium, sodium, potassium, magnesium and calcium, D is selected from one of germanium, tin, selenium, silicon, antimony, arsenic and aluminum, and the value range of x is more than or equal to 1 and less than or equal to 3, for example, x is 1,2 or 3, and the like.
According to the electrochemical device, at least one of the positive electrode active material layer 110, the negative electrode active material layer 210 and the electrolyte comprises the fluorine additive, the fluorine additive can be decomposed on the surfaces of the positive electrode sheet 100 and the negative electrode sheet 200 and participate in forming a protective layer containing a metal element, the protective layer can inhibit the dissolution and deposition of Co element to a certain extent, meanwhile, the content of inorganic substances in the protective layer on the surfaces of the positive electrode sheet 100 and the negative electrode sheet 200 is increased, the rise of the internal temperature of the electrochemical device under high-temperature abuse is reduced, and the shrinkage of the isolating membrane 300 is reduced. And the shrink of diaphragm not only receives the influence of temperature, and the thickness of diaphragm self also has certain influence to the degree of shrink, and, this application still sets up barrier film 300 and surpasss anodal edge portion 101 of positive plate 100, and prescribe a limit to two parameters of the length that barrier film 300 surpassed anodal edge portion 101 and the thickness of barrier film 300, and collocation fluorine class additive makes barrier film 300 be located the difficult transition shrink of high temperature thermal environment, prevents that positive plate 100 and negative pole piece 200 from contacting the short circuit, improves electrochemical device's thermal safety ability jointly.
In some exemplary embodiments, the fluorine-based additive is selected from at least one of the following: (1) lithium hexafluorogermanate and potassium hexafluorogermanate; (2) lithium hexafluorostannate; (3) lithium hexafluoroselenate; (4) Lithium hexafluorosilicate, sodium hexafluorosilicate, calcium hexafluorosilicate, magnesium hexafluorosilicate, potassium hexafluorosilicate; (5) Lithium hexafluoroantimonate, sodium hexafluoroantimonate, potassium hexafluoroantimonate; (6) potassium hexafluoroarsenate and sodium hexafluoroarsenate; (7) Lithium hexafluoroaluminate, sodium hexafluoroaluminate and potassium hexafluoroaluminate.
In some exemplary embodiments, the length a mm of the separator 300 beyond the positive edge portion 101 in the width direction of the positive electrode sheet is in a range of 0.5 ≦ a ≦ 9, for example, a mm may be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, or 9 mm, etc., although in other embodiments, the length a of the separator 300 beyond the positive edge portion 101 may be other lengths. When the length a of the separator 300 exceeding the positive electrode edge 101 is less than 0.5 mm, the length of the separator 300 exceeding the positive electrode edge 101 is too small, or the separator 300 is easily thermally shrunk to the region corresponding to the positive electrode edge 101, so that the positive electrode edge 101 is easily contacted with the negative electrode sheet 200. When the length a of the separator 300 exceeding the positive electrode edge portion 101 is greater than 9 mm, the formation of thermal shock of the separator 300 is not further improved, and the length of the separator 300 extending out of the positive electrode edge portion 101 along the width direction of the positive electrode sheet is too large, so that the separator occupies too large space, and the electrochemical device has too large volume and low energy density.
In some exemplary embodiments, the thickness b μm of the separation film 300 ranges from 3. Ltoreq. B.ltoreq.16, for example, the thickness b μm of the separation film 300 may be 3 μm, 5 μm, 6 μm, 8 μm, 10 μm, 11.5 μm, 12 μm, 14 μm, or 16 μm, or the like. Of course, in other embodiments, the thickness b of the isolation film 300 may have other thicknesses. When the thickness b of the separator 300 is less than 3 μm, the separator 300 has poor resistance to thermal shrinkage, and it is difficult to satisfy the barrier requirements of the positive electrode sheet 100 and the negative electrode sheet 200. When the thickness b of the separation film 300 is greater than 16 μm, the separation film 300 is excessively thick, occupying space, resulting in an excessively large volume of the electrochemical device and a low energy density.
In some exemplary embodiments, the separator 300 is one of a polypropylene film and a polyethylene film, and the separator 300 has good heat resistance, good thermal shrinkage stability with the aid of a fluorine-based additive, and good barrier effect on the positive electrode sheet 100 and the negative electrode sheet 200.
In some exemplary embodiments, the positive electrode active material layer 110 includes a fluorine-based additive, and the fluorine-based additive is included in the positive electrode active material layer 110 in an amount of X by mass 1 And X is more than or equal to 0.0001% 1 3.0% or less, for example, X 1 May be 0.0001%, 0.01%, 0.5%, 1.0%, 1.2%, 1.5%, 2.0%, 3.0%, etc. When X is present 1 Greater than 3.0%Thermal safety performance of the electrochemical device was not further improved when X 1 When the content is less than 0.0001%, the thermal safety of the electrochemical device cannot be improved.
In some exemplary embodiments, the anode active material layer 210 includes a fluorine-based additive, and the fluorine-based additive is included in the anode active material layer 210 by a mass percentage of X 2 And X is more than or equal to 0.0001% 2 ≦ 3.0% e.g., X 2 May be 0.0001%, 0.02%, 0.4%, 1.0%, 1.2%, 1.8%, 2.0%, 3.0%, etc. When X is present 2 More than 3.0%, the thermal safety performance of the electrochemical device is not further improved, and when X is 2 When the content is less than 0.0001%, the thermal safety of the electrochemical device cannot be improved.
In some exemplary embodiments, the electrolyte includes a fluorine-based additive, the fluorine-based additive is present in the electrolyte in a mass percent of Y of 0.01% to 8.0%, e.g., Y can be 0.01%, 0.5%, 1.0%, 2.0%, 4.0%, 6.0%, or 8.0%, etc. When Y is greater than 8.0%, the thermal safety performance of the electrochemical device is not further improved, and when Y is less than 0.01%, the thermal safety of the electrochemical device is not improved.
Here, the positive electrode active material layer 110 and the electrolyte, the negative electrode active material layer 210 and the electrolyte, and the positive electrode active material layer 110 and the negative electrode active material layer 210 may include a fluorine-based additive, or the positive electrode active material layer 110, the negative electrode active material layer 210, and the electrolyte may include a fluorine-based additive. At this time, the contents of the positive electrode active material layer 110, the negative electrode active material layer 210, and the fluorine-based additive in the electrolytic solution each independently satisfy the above conditional expression, that is, satisfy the conditional expression 0.0001% or more and X 1 ≤3.0%、0.0001%≤X 2 Less than or equal to 3.0 percent and less than or equal to 0.01 percent and less than or equal to 8.0 percent of Y.
In some exemplary embodiments, the electrolyte further includes a first additive selected from at least one of 1,3-propane sultone and a polynitrile compound.
In some exemplary embodiments, the polynitrile compound comprises at least one of a dinitrile or a trinitrile.
The dinitrile comprises one of succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, 1,5-dicyanopentane, 1,6-dicyanohexane, tetramethyl succinonitrile, ethylene glycol bis (propionitrile) ether.
The trinitrile includes 1,3,5-pentanetrimethylnitrile, 1,2,3-propanetrinitrile, 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbonitrile, 1,2,3-tris (2-cyanoethoxy) propane.
In some exemplary embodiments, the first additive is present in the electrolyte in an amount of Z in a mass percent of 0.5% to Z10%, e.g., Z can be 0.5%, 1.0%, 1.5%, 3.2%, 4.0%, 5.5%, 7.0%, 8.0%, or 10%, etc. When the first additive is included in the electrolyte, the thermal safety performance of the electrochemical device can be further improved. The first additive is an effective positive electrode sheet 100 protective additive, and when the first additive and the fluorine additive act together, the synergistic effect of the first additive and the fluorine additive can inhibit the side reaction of the surface materials of the positive electrode sheet 100 and the negative electrode sheet 200.
In some exemplary embodiments, Y, Z satisfies the relationship: Y/Z is more than or equal to 0.002 and less than or equal to 4, when the electrolyte simultaneously comprises the first additive and the fluorine additive, the two parameters of Y and Z are controlled to meet the conditional expression, the first additive and the fluorine additive are prevented from being in transitional competition, the first additive and the fluorine additive are enabled to be fully arranged on the surfaces of the positive plate 100 and the negative plate 200, and the reaction can play a good protection effect.
The electrolyte solution further includes a lithium salt and a nonaqueous solvent, and the electrolyte solution is obtained by adding the lithium salt and at least one of the fluorine-based additive and the first additive to the nonaqueous solvent. The lithium salt is not particularly limited in the embodiments of the present application, and any lithium salt known in the art may be used as the lithium salt as long as the purpose of the present application can be achieved, and for example, the lithium salt may include LiTFSI, liPF 6 、LiBF 4 、LiAsF 6 、LiClO 4 、LiB(C 6 H 5 ) 4 、LiCH 3 SO 3 、LiCF 3 SO 3 、LiN(SO 2 CF 3 ) 2 、LiC(SO 2 CF 3 ) 3 Or LiPO 2 F 2 And the like. The non-aqueous solvent for the lithium salt in the examples of the present application is not particularly limited as long as the object of the present application can be achieved, and for example, the non-aqueous solvent may include a carbonate compound,The carbonate compound may include at least one of diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), ethylene Carbonate (EC), propylene Carbonate (PC), butylene Carbonate (BC), vinyl Ethylene Carbonate (VEC), fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, or trifluoromethylethylene carbonate.
The positive electrode active material layer 110 further includes a positive electrode active material, and the embodiment of the present application is not particularly limited as long as the object of the present application can be achieved, and for example, the positive electrode active material includes at least one of NCM811, NCM622, NCM523, NCM111, NCA, lithium iron phosphate, lithium cobaltate, lithium manganate, lithium iron manganese phosphate, or lithium titanate.
The positive electrode active material layer 110 further includes a positive electrode conductive agent and/or a positive electrode binder, and the positive electrode conductive agent in the embodiments of the present application is not particularly limited as long as the object of the present application can be achieved, and for example, the positive electrode conductive agent may include at least one of conductive carbon black, acetylene black, ketjen black, flake graphite, graphene, carbon nanotubes, or carbon fibers. The positive electrode binder in the examples of the present application is not particularly limited as long as the object of the present application can be achieved, and for example, the positive electrode binder includes at least one of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, styrene-acrylate copolymer, styrene-butadiene copolymer, polyamide, sodium carboxymethyl cellulose, polyvinyl acetate, polyvinylpyrrolidone, polyvinyl ether, polytetrafluoroethylene, polyhexafluoropropylene, or polymethyl methacrylate.
The positive electrode current collector 120 of the present application is not particularly limited, and the positive electrode current collector 120 may be any positive electrode current collector 120 known in the art, such as an aluminum foil, an aluminum alloy foil, or a composite current collector.
The anode active material layer 210 further includes an anode active material, and the anode active material of the present application is not particularly limited, and may be any anode active material of the related art, and the anode active material includes at least one of graphite, hard carbon, soft carbon, silicon carbon, silicon oxide, or the like.
The negative electrode active material layer 210 may further include a negative electrode conductive agent and/or a negative electrode binder. The negative electrode conductive agent in the embodiment of the present application is not particularly limited as long as the object of the present application can be achieved, and for example, the negative electrode conductive agent may include at least one of carbon black, acetylene black, ketjen black, flake graphite, graphene, carbon nanotubes, carbon fibers, or carbon nanowires. The negative electrode binder in the embodiments of the present application is not particularly limited as long as the object of the present application can be achieved, and for example, the negative electrode binder may include at least one of carboxymethyl cellulose (CMC), polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyaniline, polyimide, polyamideimide, polysiloxane, styrene-butadiene rubber, epoxy resin, polyester resin, polyurethane resin, or polyfluorene.
The negative electrode current collector 220 of the present application is not particularly limited, and the negative electrode current collector 220 may be any negative electrode current collector 220 known in the art, such as a copper foil, an aluminum alloy foil, or a composite current collector.
The embodiment of the present application is not particularly limited to the outer package as long as the object of the present application can be achieved, and for example, the outer package may include an aluminum plastic film outer package.
The embodiment of the application also provides electronic equipment comprising the electrochemical device.
The electronic device of the embodiment of the present application is not particularly limited, and may be any electronic device known in the art. In some embodiments, the electronic devices include, but are not limited to: notebook computers, pen-input computers, mobile computers, electronic book players, cellular phones, portable facsimile machines, portable copiers, portable printers, headphones, video recorders, liquid crystal televisions, portable cleaners, portable CD players, mini-discs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, automobiles, motorcycles, mopeds, bicycles, lighting fixtures, toys, game machines, clocks, electric tools, flashlights, cameras, large household batteries, lithium ion capacitors, and the like.
The present application will be described in further detail with reference to specific examples, which are given below by way of example of an electrochemical device as a lithium ion battery.
1. Lithium ion battery performance test method
And (3) thermal shock test: charging the lithium ion battery to be tested to 4.45V at a constant current of 0.5C under the condition of 25 ℃, charging the lithium ion battery to be tested to a constant-voltage (CV) to a current of 0.025C, vertically placing the lithium ion battery to be tested in a box body, heating the lithium ion battery to be tested to a specific temperature at a heating speed of 5 +/-2 ℃, and keeping the temperature for 100 minutes. The passing standard is that the lithium ion batteries to be tested do not catch fire or explode in the process of keeping the temperature for 100 minutes, 3 batteries are tested in each group, and all 3 batteries pass through the group, so that the group of lithium ion batteries is considered to meet the thermal shock test at a specific temperature.
2. Preparation method of lithium ion battery
1. Preparation of Positive electrode sheet 100
The positive electrode active material lithium cobaltate (the molecular formula is LiCoO) 2 ) The positive electrode adhesive polyvinylidene fluoride (PVDF), the positive electrode conductive agent conductive carbon black (Super-P) are mixed according to the mass ratio of 96:2:2, dissolving in N-methyl pyrrolidone (NMP), and uniformly mixing to prepare the anode slurry. And uniformly coating the positive electrode slurry on a positive electrode current collector 120 aluminum foil with the thickness of 12 mu m, baking for 1h at 120 ℃, and then compacting and slitting to obtain the positive electrode sheet 100.
The positive electrode slurry is not added with the fluorine additive, the fluorine additive is added into the positive electrode slurry and is uniformly stirred, and the positive electrode sheet 100 added with the fluorine additive is obtained by normal coating according to the steps.
2. Preparation of negative electrode sheet 200
Graphite serving as a negative electrode active material, sodium carboxymethyl cellulose (CMC) and styrene butadiene rubber are mixed according to a mass ratio of 85:2: dissolving the mixture 13 in water, fully mixing and stirring to obtain negative electrode slurry, uniformly coating the negative electrode slurry on a negative electrode current collector 220 copper foil with the thickness of 12 mu m, baking at 120 ℃ for 1h to obtain a negative electrode sheet 200, and then compacting and cutting to obtain the negative electrode sheet 200.
And (3) adding the fluorine additive into the negative electrode slurry without adding the fluorine additive, uniformly stirring, and normally coating according to the steps to obtain the negative electrode sheet 200 added with the fluorine additive.
3. Preparation of the electrolyte
Mixing ethylene carbonate and diethyl carbonate in a ratio of 3:7 by mass ratio while adding 1M LiPF 6 And obtaining the electrolyte base material.
And adding at least one of a fluorine additive and a first additive into the electrolyte base material to obtain an electrolyte.
4. Preparation of lithium ion battery
A polypropylene film was used as the separator 300. And sequentially laminating the positive plate 100, the isolating film 300 and the negative plate 200 in sequence to enable the isolating film 300 to be positioned between the positive plate 100 and the negative plate 200, isolating the positive plate 100 from the negative plate 200, then winding, connecting the positive tab with the positive plate 100, and connecting the negative tab with the negative plate 200 to obtain the electrode assembly. And (3) putting the electrode assembly into the inner space of an outer package, wherein the outer package is an aluminum foil packaging bag, leading the positive electrode tab and the negative electrode tab out of the inner space of the outer package to the outer space of the outer package, baking at 80 ℃ to remove water, injecting electrolyte into the inner space of the outer package, and carrying out vacuum packaging, standing, formation, shaping and other processes to obtain the lithium ion battery.
The lithium ion batteries of examples and comparative examples were prepared and tested as described above.
In table 1, examples 1-1 to 1-10 included a fluorine-based additive, the fluorine-based additive included lithium hexafluoroantimonate, and the fluorine-based additive was added to the electrolyte solution, and the content of the fluorine-based additive in the electrolyte solution was 0.5% by mass.
TABLE 1
| Item | Fluorine-based additive | Content (%) | a(mm) | b(μm) | b/a | Thermal shock temperature (. Degree.C.) |
| Comparative examples 1 to 1 | / | / | 4 | 4 | 1 | 88 |
| Comparative examples 1 to 2 | Lithium hexafluoroantimonate | 0.5 | 8 | 3 | 0.38 | 90 |
| Comparative examples 1 to 3 | Lithium hexafluoroantimonate | 0.5 | 0.5 | 16 | 32 | 92 |
| Example 1-1 | Lithium hexafluoroantimonate | 0.5 | 8 | 3.2 | 0.4 | 101 |
| Examples 1 to 2 | Lithium hexafluoroantimonate | 0.5 | 4 | 4 | 1 | 117 |
| Examples 1 to 3 | Lithium hexafluoroantimonate | 0.5 | 4 | 8 | 2 | 118 |
| Examples 1 to 4 | Lithium hexafluorostannate | 0.5 | 4 | 6 | 1.5 | 120 |
| Examples 1 to 5 | Lithium hexafluoroaluminate | 0.5 | 4 | 6 | 1.5 | 118 |
| Examples 1 to 6 | Hexafluorogermanic acid potassium salt | 0.5 | 4 | 6 | 1.5 | 118 |
| Examples 1 to 7 | Lithium hexafluoroantimonate | 0.5 | 2 | 10 | 5 | 121 |
| Examples 1 to 8 | Lithium hexafluoroantimonate | 0.5 | 1 | 10 | 10 | 118 |
| Examples 1 to 9 | Lithium hexafluoroantimonate | 0.5 | 1 | 15 | 15 | 109 |
| Examples 1 to 10 | Lithium hexafluoroantimonate | 0.5 | 0.5 | 15 | 30 | 105 |
In table 1, it can be seen from comparative examples 1-1 and examples 1-2 that the thermal shock temperature of the lithium ion battery can be significantly increased by adding the fluorine-based additive. Meanwhile, a series of ratios of b to a are obtained by adjusting the sizes of a and b, wherein when b/a is greater than 30 or b/a is less than 0.4, the isolating film 300 is too thin, and the size of the isolating film 300 is small, so that the isolating film 300 is easy to excessively shrink under a high-temperature condition, the thermal shock performance of the isolating film 300 is poor, and further the positive plate 100 and the negative plate 200 are in contact short circuit, so that the lithium ion battery fails. When the a and b parameters are within the range that b/a is not less than 0.4 and not more than 30, the isolating membrane 300 has better thermal shock performance, so that the lithium ion battery has better high-temperature resistance. Preferably, both parameters a and b satisfy the conditional expression 0.8. Ltoreq. B/a. Ltoreq.10.
In table 2, examples 2-1 to 2-14 included a fluorine-based additive, the fluorine-based additive included lithium hexafluoroantimonate, and the fluorine-based additive was added to the electrolyte solution, and the content of the fluorine-based additive in the electrolyte solution was 0.5% by mass.
TABLE 2
| Item | a(mm) | b(μm) | b/a | Thermal shock temperature (. Degree. C.) |
| Example 2-1 | 0.5 | 8 | 16 | 110 |
| Examples 2 to 2 | 1 | 8 | 8 | 115 |
| Examples 2 to 3 | 1.5 | 8 | 5.3 | 116 |
| Examples 2 to 4 | 3 | 8 | 2.7 | 118 |
| Examples 1 to 3 | 4 | 8 | 2 | 118 |
| Examples 2 to 5 | 7 | 8 | 1.1 | 117 |
| Examples 2 to 6 | 9 | 8 | 0.9 | 116 |
| Examples 2 to 7 | 10 | 8 | 0.8 | 116 |
| Examples 2 to 8 | 2 | 3 | 1.5 | 113 |
| Examples 2 to 9 | 2 | 5 | 2.5 | 114 |
| Examples 2 to 10 | 2 | 8 | 4 | 114 |
| Examples 2 to 11 | 2 | 10 | 5 | 118 |
| Examples 2 to 12 | 2 | 14 | 7 | 121 |
| Examples 2 to 13 | 2 | 16 | 8 | 122 |
| Examples 2 to 14 | 2 | 17 | 8.5 | 118 |
In Table 2, when a satisfies the conditional expression 0.5. Ltoreq. A.ltoreq.9, and b satisfies the conditional expression 3. Ltoreq. B.ltoreq.16, the thermal shock property of the separator 300 is better. When the length of the separator 300 below the tab beyond the positive electrode tab 100 along the width direction of the positive electrode tab is too short, or the separator 300 is too thin, the risk of short-circuiting the positive electrode tab 100 and the negative electrode tab 200 increases; when the length of the separator 300 exceeding the positive electrode tab 100 along the width direction of the positive electrode tab is too long or the separator 300 is too thick, the thermal shock performance is not further improved, and the volumetric energy density of the battery is affected.
In table 3, in examples 3-1 to 3-35 and comparative examples 3-1 to 3-5, a is 4,b is 4, at least one of the positive electrode active material layer 110 of the positive electrode sheet 100, the negative electrode active material layer 210 of the negative electrode sheet 200, and the electrolyte includes a fluorine-based additive, and the addition position and the addition amount of the fluorine-based additive are specifically shown in table 3
TABLE 3
| Item | Fluorine-based additive | Adding position | Fluorine-containing additive content (%) | Thermal shock temperature (. Degree.C.) |
| Comparative examples 1 to 1 | / | / | / | 88 |
| Example 3-1 | Lithium hexafluorogermanate | Positive plate | 0.1 | 113 |
| Examples 3 to 2 | Lithium hexafluorostannate | Positive plate | 0.1 | 115 |
| Examples 3 to 3 | Lithium hexafluoroselenate | Positive plate | 0.1 | 114 |
| Examples 3 to 4 | Lithium hexafluorosilicate | Positive plate | 0.1 | 116 |
| Examples 3 to 5 | Magnesium hexafluorosilicate | Positive plate | 0.1 | 116 |
| Examples 3 to 6 | Lithium hexafluoroantimonate | Positive plate | 0.1 | 115 |
| Examples 3 to 7 | Potassium hexafluoroantimonate | Positive plate | 0.1 | 116 |
| Examples 3 to 8 | Hexafluoroarsenate potassium salt | Positive plate | 0.1 | 112 |
| Examples 3 to 9 | Lithium hexafluoroaluminate | Positive plate | 0.1 | 116 |
| Examples 3 to 10 | Sodium hexafluoroaluminate | Positive plate | 0.1 | 114 |
| Examples 3 to 11 | Lithium hexafluorostannate + lithium hexafluoroantimonate | Positive plate | 0.1+0.1 | 118 |
| Examples 3 to 12 | Potassium hexafluoroantimonate + sodium hexafluoroaluminate | Positive plate | 0.1+0.1 | 118 |
| Examples 3 to 13 | Lithium hexafluoroselenate + lithium hexafluoroaluminate + lithium hexafluoroantimonate | Positive plate | 0.05+0.1+0.1 | 120 |
| Comparative example 3-1 | Lithium hexafluorosilicate | Positive plate | 0.00005 | 90 |
| Examples 3 to 14 | Lithium hexafluorosilicate | Positive plate | 0.0001 | 110 |
| Examples 3 to 15 | Lithium hexafluorosilicate | Positive plate | 0.01 | 118 |
| Examples 3 to 16 | Lithium hexafluorosilicate | Positive plate | 0.5 | 118 |
| Examples 3 to 17 | Lithium hexafluorosilicate | Positive plate | 1 | 119 |
| Examples 3 to 18 | Lithium hexafluorosilicate | Positive plate | 2 | 124 |
| Examples 3 to 19 | Lithium hexafluorosilicate | Positive plate | 3 | 125 |
| Comparative examples 3 to 2 | Lithium hexafluorosilicate | Positive plate | 3.5 | 125 |
| Comparative examples 3 to 3 | Lithium hexafluoroantimonate | Negative plate | 0.00005 | 87 |
| Examples 3 to 20 | Lithium hexafluoroantimonate | Negative plate | 0.0001 | 108 |
| Examples 3 to 21 | Lithium hexafluoroantimonate | Negative plate | 0.01 | 109 |
| Examples 3 to 22 | Lithium hexafluoroantimonate | Negative plate | 0.5 | 109 |
| Examples 3 to 23 | Lithium hexafluoroantimonate | Negative plate | 1 | 112 |
| Examples 3 to 24 | Lithium hexafluoroantimonate | Negative plate | 2 | 118 |
| Examples 3 to 25 | Lithium hexafluoroantimonate | Negative plate | 3 | 120 |
| Comparative examples 3 to 4 | Lithium hexafluoroantimonate | Negative plate | 3.5 | 120 |
| Examples 3 to 26 | Sodium hexafluoroaluminate | Electrolyte solution | 0.005 | 89 |
| Examples 3 to 27 | Sodium hexafluoroaluminate | Electrolyte solution | 0.01 | 108 |
| Examples 3 to 28 | Sodium hexafluoroaluminate | Electrolyte solution | 1 | 112 |
| Examples 3 to 29 | Sodium hexafluoroaluminate | Electrolyte solution | 3 | 116 |
| Examples 3 to 30 | Sodium hexafluoroaluminate | Electrolyte solution | 5 | 120 |
| Examples 3 to 31 | Sodium hexafluoroaluminate | Electrolyte solution | 8 | 121 |
| Comparative examples 3 to 5 comparative examples 3 to 4 | Sodium hexafluoroaluminate | Electrolyte solution | 9 | 121 |
| Examples 3 to 32 | Hexafluoroantimonate/hexafluoroarsenate | Positive electrode/negative electrodePole | 0.1/0.1 | 118 |
| Examples 3 to 33 | Potassium hexafluoroantimonate/potassium hexafluoroarsenate | Positive electrode/electrolyte | 0.1/0.1 | 115 |
| Examples 3 to 34 | Hexafluoroantimonate/hexafluoroarsenate | Negative electrode/electrolyte | 0.1/0.1 | 119 |
| Examples 3 to 35 | Hexafluoroantimonate/hexafluoroarsenate | Positive electrode/negative electrode/electrolyte | 0.1/0.1/0.1 | 116 |
As can be seen from table 3, the thermal shock performance of the lithium ion battery is significantly improved by adding different types of fluorine additives to the positive electrode sheet 100, the negative electrode sheet 200, and the electrolyte. The content of the fluorine additives in the positive plate 100 and the negative plate 200 is adjusted to obtain different performance improvements, and when the content of the fluorine additives in the positive plate 100 and the negative plate 200 is more than 3%, the thermal safety performance is not further improved; when the content of the fluorine-based additive in the positive and negative electrode tabs 100 and 200 is too low, thermal safety cannot be improved. In the same way, the same rule is obtained by adding fluorine additives into the electrolyte. In examples 3-32 to 3-35, the improvement object was also achieved by adding the fluorine-based additive to the positive electrode sheet 100 and the electrolyte, the negative electrode sheet 200 and the electrolyte, and the positive electrode sheet 100 and the negative electrode sheet 200 at the same time, and by adding the fluorine-based additive to the positive electrode sheet 100, the negative electrode sheet 200, and the electrolyte, and therefore the fluorine-based additive was not limited to being added to a certain portion in the battery.
In table 4, example 4-1 to example 4-10, a was 4,b was 4, the electrolyte included a fluorine-based additive, the fluorine-based additive included sodium hexafluoroaluminate, and the fluorine-based additive was 0.01% by mass in the electrolyte. The electrolyte also includes a first additive.
TABLE 4
| Item | Fluorine-based additive | First additive | Z(%) | Thermal shock temperature (. Degree.C.) |
| Examples 3 to 31 | Sodium hexafluoroaluminate | / | / | 108 |
| Comparative example 4-1 | Sodium hexafluoroaluminate | Octanedinitrile | 0.3 | 108 |
| Example 4-1 | Sodium hexafluoroaluminate | Octanedionitrile | 0.5 | 110 |
| Example 4-2 | Sodium hexafluoroaluminate | Octanedinitrile | 1 | 115 |
| Examples 4 to 3 | Sodium hexafluoroaluminate | Octanedionitrile | 5 | 118 |
| Examples 4 to 4 | Sodium hexafluoroaluminate | Octanedinitrile | 8 | 120 |
| Examples 4 to 5 | Sodium hexafluoroaluminate | Octanedionitrile | 10 | 121 |
| Comparative examples 4 and 2 | Sodium hexafluoroaluminate | Octanedionitrile | 11 | 121 |
| Examples 4 to 7 | Sodium hexafluoroaluminate | 1,3,5-Pentamitril | 5 | 117 |
| Examples 4 to 8 | Sodium hexafluoroaluminate | 1,3 propane sultone | 2 | 117 |
| Examples 4 to 9 | Sodium hexafluoroaluminate | Succinonitrile + adiponitrile | 1+1 | 116 |
As can be seen from table 4, in examples 4-1 to 4-8, the thermal safety performance can be further improved when the first additive is added to the electrolyte, relative to examples 3-31. The first additive is an effective positive electrode protection additive, and when the first additive and the fluorine additive act together, the synergistic effect of the first additive and the fluorine additive can inhibit side reactions on the surface layers of the positive electrode sheet 100 and the negative electrode sheet 200. The optimal adding amount of the first additive is between 0.5 and 10 percent by adjusting the using amount of the first additive; in comparative example 4-1, when the addition amount was too small, stable protection could not be formed on the surface layers of the positive electrode sheet 100 and the negative electrode sheet 200, and no improvement was made on the cycle; in comparative example 4-2, when the first additive was added in an amount exceeding 10%, not only the thermal safety performance of the lithium ion battery could not be improved further, but also other aspects such as increase in resistance and deterioration in cycle performance were brought about.
In table 5, in examples 5-1 to 5-8, a was 4,b was 4, the electrolyte included a fluorine-based additive, the fluorine-based additive included sodium hexafluoroaluminate, and the fluorine-based additive was 0.01% by mass in the electrolyte. The electrolyte also comprises a first additive, wherein the first additive is octanedionitrile, and the mass content of the octanedionitrile in the electrolyte is 5 percent.
TABLE 5
| Item | Fluorine-containing additive | Adding position | Y(%) | First additive | Z | Y/Z | Thermal shock temperature (. Degree.C.) |
| Comparative example 5-1 | Sodium hexafluoroaluminate | Electrolyte solution | 0.01 | Octanedionitrile | 6 | 0.0016 | 110 |
| Examples 4 to 4 | Hexafluoro benzeneSodium aluminate | Electrolyte solution | 0.01 | Octanedionitrile | 5 | 0.002 | 118 |
| Example 5-1 | Sodium hexafluoroaluminate | Electrolyte solution | 0.1 | Octanedionitrile | 5 | 0.02 | 119 |
| Examples 5 and 2 | Sodium hexafluoroaluminate | Electrolyte solution | 1 | Octanedionitrile | 5 | 0.2 | 120 |
| Examples 5 to 3 | Sodium hexafluoroaluminate | Electrolyte solution | 3 | Octanedionitrile | 5 | 0.6 | 125 |
| Examples 5 to 4 | Sodium hexafluoroaluminate | Electrolyte solution | 5 | Octanedinitrile | 2 | 2.5 | 117 |
| Examples 5 to 5 | Sodium hexafluoroaluminate | Electrolyte solution | 6 | Octanedionitrile | 1.5 | 4 | 115 |
| Comparative examples 5 to 2 | Sodium hexafluoroaluminate | Electrolyte solution | 6 | Octanedionitrile | 1.4 | 4.2 | 109 |
When the electrolyte simultaneously comprises the fluorine additive and the first additive, the ratio of the fluorine additive to the first additive needs to be controlled within a certain range. Wherein, when the fluorine additive and the first additive are both added into the electrolyte, the fluorine additive and the first additive have obvious competitive reaction on the surface layers of the positive plate 100 and the negative plate 200, and it can be seen from the examples 5-5 that when the addition amounts of the fluorine additive and the first additive satisfy the conditional expression that Y/Z is more than or equal to 0.002 and less than or equal to 4, the fluorine additive and the first additive can be ensured to fully react on the surface layers of the positive plate 100 and the negative plate 200, so as to exert better protection effect, and the thermal shock performance of the lithium ion battery is better.
The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present application, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of the description, but it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation and operate, and therefore the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the above terms can be understood according to the specific situation by those skilled in the art.
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, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. An electrochemical device is characterized by comprising a positive plate, a negative plate, electrolyte and an isolating membrane, wherein the isolating membrane is arranged between the positive plate and the negative plate;
wherein, along the width direction of the positive plate, the length of the isolating film exceeding the positive plate is a mm, the thickness of the isolating film is b μm, and b/a is more than or equal to 0.4 and less than or equal to 30;
the positive plate comprises a positive active material layer, the negative plate comprises a negative active material layer, at least one of the positive active material layer, the negative active material layer and the electrolyte comprises a fluorine additive, and the fluorine additive is selected from at least one of substances with a molecular formula shown in a formula I;
A x DF 6 the compound has a structure shown in a formula I,
wherein A is selected from one of lithium, sodium, potassium, magnesium and calcium, D is selected from one of germanium, tin, selenium, silicon, antimony, arsenic and aluminum,
the value range of x is more than or equal to 1 and less than or equal to 3.
2. The electrochemical device according to claim 1, wherein the fluorine-based additive is selected from at least one of the following:
(1) Lithium hexafluorogermanate and potassium hexafluorogermanate;
(2) Lithium hexafluorostannate;
(3) Lithium hexafluoroselenate;
(4) Lithium hexafluorosilicate, sodium hexafluorosilicate, calcium hexafluorosilicate, magnesium hexafluorosilicate, potassium hexafluorosilicate;
(5) Lithium hexafluoroantimonate, sodium hexafluoroantimonate, potassium hexafluoroantimonate;
(6) Potassium hexafluoroarsenate, sodium hexafluoroarsenate;
(7) Lithium hexafluoroaluminate, sodium hexafluoroaluminate and potassium hexafluoroaluminate.
3. The electrochemical device of claim 1, wherein the electrochemical device satisfies at least one of the following conditions:
condition i: the length a mm of the isolating film exceeding the positive plate meets the following requirements: a is more than or equal to 0.5 and less than or equal to 9;
condition ii: the thickness b mu m of the isolating film is within the range of 3-16;
condition iii: a and b satisfy the relation: b/a is more than or equal to 0.8 and less than or equal to 10.
4. The electrochemical device according to claim 1,
the positive electrode active material layer comprises a fluorine additive, and the mass percentage of the fluorine additive in the positive electrode active material layer is X 1 And X is more than or equal to 0.0001 percent 1 Less than or equal to 3.0 percent; and/or the presence of a gas in the gas,
the negative electrode active material layer comprises a fluorine additive, and the mass percentage of the fluorine additive in the negative electrode active material layer is X 2 And X is more than or equal to 0.0001% 2 ≤3.0%。
5. The electrochemical device according to claim 1, wherein the electrolyte comprises a fluorine additive, and the fluorine additive is contained in the electrolyte in a mass percentage of Y, and Y is between 0.01% and 8.0%.
6. The electrochemical device of claim 5, wherein said electrolyte further comprises a first additive selected from at least one of 1,3-propane sultone and a polynitrile compound.
7. The electrochemical device of claim 6, wherein the polynitrile compound comprises at least one of a dinitrile or a dinitrile;
the dinitrile comprises one of succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, 1,5-dicyanopentane, 1,6-dicyanohexane, tetramethyl succinonitrile, ethylene glycol bis (propionitrile) ether;
the trinitrile includes one of 1,3,5-pentanetrimethylnitrile, 1,2,3-propanetrinitrile, 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbonitrile, 1,2,3-tris (2-cyanoethoxy) propane.
8. The electrochemical device according to claim 6, wherein the mass percentage of the first additive in the electrolyte solution is Z, and Z is 0.5% to 10%.
9. The electrochemical device of claim 8, wherein Y, Z satisfies the relationship: Y/Z is more than or equal to 0.002 and less than or equal to 4.
10. An electronic device comprising an electrochemical device according to any one of claims 1 to 9.
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