Electrochemical device and electronic device

Abstract

The application provides an electrochemical device and an electronic device. The electrochemical device comprises a positive electrode, a negative electrode and an electrolyte. The positive electrode comprises a positive electrode active material, the positive electrode active material comprises an A element, the A element is selected from at least one of La, Y or Nb, the mass content of the A element is x% based on the mass of the positive electrode active material, and the electrolyte comprises a compound of formula (I), the mass content of the compound of formula (I) is a% based on the mass of the electrolyte. The technical scheme of the application can effectively improve the high-temperature cycle and room-temperature cycle performance of the electrochemical device.

Description

Technical Field

[0001] This application relates to the field of electrochemistry, and more particularly to an electrochemical device and an electronic device. Background Technology

[0002] Lithium-ion batteries possess advantages such as high energy density, light weight, and long cycle life, making them widely used in consumer batteries. With the trend towards thinner and more portable electronic products, the demands on lithium-ion batteries are constantly increasing. Developing lithium-ion batteries with higher volumetric energy density and longer cycle life is one of the main market needs. In addition to high-temperature cycle stability, more stringent requirements are being placed on product usage conditions, such as the interval cycle (rest period before and after a full charge at high temperatures). Currently, doping elements in cathode materials can increase the structural stability of the material and improve high-temperature cycle retention, but excessive doping can lead to a significant decrease in capacity. Most cathode protection additives can improve high-temperature cycle performance and ITC, but the improvement is limited and cannot be simultaneously applied to room-temperature cycling. Summary of the Invention

[0003] In view of the problems existing in the background art, the purpose of this application is to provide an electrochemical device and an electronic device.

[0004] To achieve the above objectives, this application provides an electrochemical device comprising a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode comprises a positive electrode active material, the positive electrode active material comprising element A, the element A being selected from at least one of La, Y, or Nb; the mass content of element A is x% based on the mass of the positive electrode active material; the electrolyte comprises a compound of formula (I).

[0005]

[0006] Where M is selected from at least one of formula (IA) or formula (IB):

[0007]

[0008] R1 is selected from substituted or unsubstituted C. 1-6 Alkyl group, substituted or unsubstituted C 2-6 Alkyl groups containing ether bonds, wherein, when substituted, the substituents are selected from fluorine atoms, C... 2-6 olefin group, C 2-6 At least one of alkynyl, cyano, sulfonyl or silyl groups;

[0009] R2, R3, R4, R5, and R6 are each independently selected from hydrogen, substituted, or unsubstituted C atoms. 1-6 Alkyl, substituted or unsubstituted C 2-6 olefinic, substituted or unsubstituted C 2-6Alkyne group, substituted or unsubstituted C 2-6 Contains an ether bond alkyl group, a fluorine atom, a cyano group or a sulfonyl group, wherein, when substituted, the substituent is selected from at least one of a fluorine atom, an aldehyde group or a cyano group;

[0010] In formula (IA), R3 and R4 can be bonded to form a ring structure, and in formula (IB), R5 and R6 can be bonded to form a ring structure.

[0011] Based on the mass of the electrolyte, the mass content of the compound of formula (I) is a%.

[0012] In some embodiments, the compound of formula (I) is selected from at least one of the compounds represented by formulas (I-1) to (I-20):

[0013]

[0014]

[0015] In some embodiments, x, a, x / a, and at least one of the following conditions (a) to (c) are satisfied:

[0016] (a) 0.05% ≤ x ≤ 2%;

[0017] (b) 0.01% ≤ a ≤ 2%;

[0018] (c) 0.1 < x / a ≤ 5, preferably 1.5 ≤ x / a ≤ 3.

[0019] In some embodiments, the electrolyte further comprises a trinitrile compound; the mass content of the trinitrile compound is b% based on the mass of the electrolyte, wherein 0.1 < b ≤ 5; the trinitrile compound is selected from at least one of 1,2,4-butanetrionitrile, 1,3,5-benzenetrionitrile, 2,4,6-trifluorobenzene-1,3,5-trinitrile, 2-bromobenzene-1,3,5-trinitrile, 1,3,6-hexanetrionitrile, 1,2,3-propanetrionitrile, 1,3,5-pentanetrionitrile, or J.,2,6-hexanetrionitrile.

[0020] In some embodiments, the electrolyte further comprises a compound represented by formula (II);

[0021]

[0022] Where m is 1, 2, or 3, and A is independently selected from formula (I-B1) or formula (I-B2).

[0023]

[0024] Among them, R 11 R12 R 13 Each is independently selected from covalent single bonds, substituted or unsubstituted C1-C6 alkylene groups, substituted or unsubstituted C2-C6 alkenyl groups, substituted or unsubstituted C2-C6 alkenyl groups. 10 The alkynyl group or substituted or unsubstituted C3-C 10 When the alicyclic hydrocarbon group is substituted, the substituent is selected from halogens.

[0025] Based on the mass of the electrolyte, the content of the compound represented by formula (II) is c%, wherein: 0.1 < c ≤ 5, preferably, 0.1 < c ≤ 4.

[0026] In some embodiments, the compound of formula (II) is selected from at least one of the compounds represented by formulas (II-1) to (II-7):

[0027]

[0028] In some embodiments, the electrolyte further comprises a dinitrile compound; the mass content of the dinitrile compound is 0.1% to 10% based on the mass of the electrolyte; the dinitrile compound is selected from at least one of malononitrile, butadionitrile, glutaronitrile, adiponitrile, octadionitrile, terephthalonitrile, tetradecanedionitrile, azomalononitrile, methyleneglutaronitrile, or pentenedionitrile.

[0029] In some embodiments, the relationship between b and a satisfies: 4 < b / a ≤ 8.

[0030] In some embodiments, b satisfies: 0.1 < b ≤ 5; c satisfies: 0.1 < c ≤ 4; and b and c satisfy: 0.5 ≤ b / c ≤ 10.

[0031] In some embodiments, the relationship between b and a satisfies: 5 ≤ b / a ≤ 6; and the relationship between b and c satisfies: 1 ≤ b / c ≤ 8.3.

[0032] In some embodiments, this application also provides an electronic device, which includes the electrochemical device described above.

[0033] This application includes at least the following beneficial effects: the technical solution of this application can effectively improve the high-temperature cycling and room-temperature cycling performance of electrochemical devices. Detailed Implementation

[0034] It will be understood that the disclosed embodiments are merely examples of this application, which can be implemented in various forms. Therefore, the specific details disclosed herein should not be construed as limiting, but are intended only as the basis for the claims and as an illustrative basis to teach those skilled in the art how to implement this application in various ways.

[0035] In the description of this application, unless otherwise expressly specified and limited, the terms "Form I", "Form II", etc. are used for illustrative purposes only and should not be construed as indicating or implying relative importance or interrelationship.

[0036] (Electrochemical device)

[0037] Electrochemical devices can be capacitors, lithium-ion batteries, sodium-ion batteries, or zinc-ion batteries. For example, they can be lithium-ion capacitors, primary lithium-ion batteries, or secondary lithium-ion batteries.

[0038] This application discloses an electrochemical device comprising a positive electrode, a negative electrode, and an electrolyte.

[0039] Electrolyte

[0040] In some embodiments, the electrolyte comprises a compound of formula (I),

[0041]

[0042] Where M is selected from at least one of formula (IA) or formula (IB):

[0043]

[0044] R1 is selected from substituted or unsubstituted C. 1-6 Alkyl group or substituted or unsubstituted C 2-6 Alkyl groups containing ether bonds, wherein, when substituted, the substituents are selected from fluorine atoms, C... 2-6 olefin group, C 2-6 At least one of alkynyl, cyano, sulfonyl or silyl groups;

[0045] R2, R3, R4, R5, and R6 are each independently selected from hydrogen, substituted, or unsubstituted C atoms. 1-6 Alkyl, substituted or unsubstituted C 2-6 olefinic, substituted or unsubstituted C 2-6 Alkyne group, substituted or unsubstituted C 2-6 Contains an ether bond alkyl group, a fluorine atom, a cyano group or a sulfonyl group, wherein, when substituted, the substituent is selected from at least one of a fluorine atom, an aldehyde group or a cyano group;

[0046] In formula (IA), R3 and R4 can be bonded to form a ring structure, and in formula (IB), R5 and R6 can be bonded to form a ring structure.

[0047] Based on the mass of the electrolyte, the mass content of the compound of formula (I) is a%, satisfying 0.01% ≤ a ≤ 2%.

[0048] In this application, transition metal elements such as La, Y, or Nb are used to dope the cathode material, which can expand the interlayer spacing and stabilize the crystal structure. However, due to the large radius of the dopant elements, they cannot completely enter the lattice, resulting in an uneven coating layer on the particle surface. The nitrogen atoms of the compound of formula (I) contain lone pairs of electrons, which easily complex and adsorb with the transition metals and dopant ions on the cathode surface to form a stable interface film. This interface film can prevent the coating layer from falling off, and the skeletal support of the inorganic coating layer gives the interface film both high mechanical strength and toughness, thus improving cycle performance.

[0049] In some embodiments, the compound of formula (I) is selected from at least one of the compounds represented by formulas (I-1) to (I-20):

[0050]

[0051] In some embodiments, the electrolyte further comprises a trinitrile compound; the mass content of the trinitrile compound is b% based on the mass of the electrolyte, wherein 0.1 < b ≤ 5. The trinitrile compound is selected from at least one of 1,2,4-butanetrionitrile, 1,3,5-benzenetrionitrile, 2,4,6-trifluorobenzene-1,3,5-trinitrile, 2-bromobenzene-1,3,5-trinitrile, 1,3,6-hexanetrionitrile, 1,2,3-propanetrioxynitrile, 1,3,5-pentanetrioxynitrile, or 1,2,6-hexanetrioxynitrile.

[0052] In some embodiments, the electrolyte further comprises a compound represented by formula (II);

[0053]

[0054] Where m is 1, 2, or 3, and A is independently selected from formula (I-B1) or formula (I-B2).

[0055]

[0056] Among them, R 11 R 12 R 13 Each is independently selected from covalent single bonds, substituted or unsubstituted C1-C6 alkylene groups, substituted or unsubstituted C2-C6 alkenyl groups, substituted or unsubstituted C2-C6 alkenyl groups. 10 The alkynyl group or substituted or unsubstituted C3-C 10 The alicyclic hydrocarbon group, when substituted, is selected from halogens; based on the mass of the electrolyte, the content of the compound represented by formula (II) is c%, wherein: 0.1 < c ≤ 5.

[0057] In some embodiments, the compound of formula (II) is selected from at least one of the compounds represented by formulas (II-1) to (II-7):

[0058]

[0059]

[0060] In some embodiments, the electrolyte further comprises a dinitrile compound; the mass content of the dinitrile compound is 0.1% to 10% based on the mass of the electrolyte. The dinitrile compound is selected from at least one of malononitrile, butadionitrile, glutaronitrile, adiponitrile, octadionitrile, terephthalonitrile, tetradecanedionitrile, azomalononitrile, methyleneglutaronitrile, or pentenedionitrile.

[0061] In this application, adding nitrile alone may affect the cycle performance of the electrochemical device. This may be due to the side reaction of nitrile at the negative electrode. However, when compound (I) is added in combination with nitrile, compound (I) can preferentially undergo reduction reaction at the negative electrode compared to conventional negative electrode film-forming additives. Compound (I) can generate a stable SEI, effectively blocking the side reaction of nitrile at the negative electrode. This allows the nitrile compound to continuously act on the positive electrode, thereby improving the room temperature and high temperature cycle performance of the electrochemical device.

[0062] In some embodiments, the relationship between b and a satisfies: 4 < b / a ≤ 8.

[0063] In some embodiments, b satisfies: 0.1 < b ≤ 4; c satisfies: 0.1 < c ≤ 4; and b and c satisfy: 0.5 ≤ b / c ≤ 10.

[0064] In some embodiments, the relationship between b and a satisfies: 5 ≤ b / a ≤ 6; and the relationship between b and c satisfies: 1 ≤ b / c ≤ 8.3.

[0065] <Positive Electrode Tablets>

[0066] In some embodiments, the positive electrode sheet includes a positive current collector and a positive electrode film disposed on at least one surface of the positive current collector. The positive electrode film typically includes a positive electrode active material and optionally a positive electrode binder and a conductive agent.

[0067] In some embodiments, the structure of the positive electrode is a structure known in the art for use in electrochemical devices.

[0068] In some embodiments, the positive current collector may be a metal foil or a porous metal plate, such as a foil or porous plate made of metals or alloys thereof, such as aluminum, copper, nickel, titanium, or silver. As an example, the positive current collector may be an aluminum foil.

[0069] In some embodiments, the positive electrode includes a positive electrode active material, the positive electrode active material containing element A, the element A being selected from at least one of La, Y, or Nb;

[0070] Based on the mass of the positive electrode active material, the mass content of element A is x%.

[0071] In some embodiments, at least one of the following conditions (a) to (c) is satisfied:

[0072] (a) 0.05% ≤ x ≤ 2%;

[0073] (b) 0.01% ≤ a ≤ 2%;

[0074] (c) 0.1 < x / a ≤ 5.

[0075] Negative electrode film

[0076] In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is disposed on the surface of the negative electrode current collector. The negative electrode active material layer includes a negative electrode active material.

[0077] In some embodiments, the structure of the negative electrode is a structure known in the art for use in electrochemical devices.

[0078] The negative electrode current collector has two surfaces opposite each other in its thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0079] The negative electrode current collector can be a metal foil or a porous metal plate, such as a foil or porous plate of metals or alloys thereof, such as copper, nickel, titanium, or iron. As an example, the negative electrode current collector is copper foil.

[0080] In some embodiments, the negative electrode active material layer further includes a negative electrode binder and a negative electrode conductive agent. In some embodiments, the negative electrode binder includes at least one of the following: ethylene difluoropropylene-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, and nylon.

[0081] In some embodiments, the specific type of negative electrode conductive agent is not limited and can be selected according to requirements. As an example, the conductive agent includes, but is not limited to, at least one of conductive graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0082] In some embodiments, the negative electrode active material layer further includes a thickener. The specific type of thickener is not limited and can be selected as needed. As an example, thickeners include, but are not limited to, sodium carboxymethyl cellulose (CMC).

[0083] In some embodiments, the method for preparing the negative electrode sheet is a method known in the art for preparing negative electrode sheets that can be used in electrochemical devices. In some embodiments, the negative electrode active material, along with optional conductive agents, binders, and thickeners, is typically dispersed in a solvent to form a uniform negative electrode slurry. The negative electrode slurry is then coated onto a negative electrode current collector, and the negative electrode sheet is obtained through processes such as drying and cold pressing. The solvent is a solvent known in the art that can be used as a negative electrode active material layer, such as, but not limited to, water. The solvent can be N-methylpyrrolidone (NMP) or deionized water, but this application is not limited to these.

[0084] <Isolation membrane>

[0085] The separator is a separator known in the art that can be used in electrochemical devices, such as, but not limited to, polyolefin microporous membranes. In some embodiments, the separator includes at least one selected from polyethylene (PE), ethylene-propylene copolymer, polypropylene (PP), ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-methyl methacrylate copolymer.

[0086] In some embodiments, the separator is a single-layer separator or a multi-layer separator.

[0087] In some embodiments, the separator membrane is coated with a coating. In some embodiments, the coating includes at least one of an organic coating and an inorganic coating, wherein the organic coating includes at least one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyimide, acrylonitrile-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polymethyl methacrylate, polymethyl acrylate, polyethyl acrylate, acrylic-styrene copolymer, polydimethylsiloxane, sodium polyacrylate, and sodium carboxymethyl cellulose, and the inorganic coating includes at least one of SiO2, Al2O3, CaO, TiO2, ZnO2, MgO, ZrO2, and SnO2.

[0088] This application does not impose any particular limitations on the morphology and thickness of the separator. The method for preparing the separator is a well-known method in the art and can be used in electrochemical devices.

[0089] <Shell>

[0090] The housing is used to encapsulate the electrode assembly. In some embodiments, the housing can be a rigid housing or a flexible housing. The rigid housing is made of materials such as metal. The flexible housing is made of materials such as metal-plastic film, for example, aluminum-plastic film, steel-plastic film, etc.

[0091] In some embodiments, the positive electrode, the separator, and the negative electrode can be fabricated into an electrode assembly by a winding process or a stacking process. The electrode assembly is placed in a housing, an electrolyte is injected, and after vacuum sealing, settling, formation, shaping, and capacity separation, an electrochemical device can be obtained.

[0092] In other embodiments, the battery cells are stacked.

[0093] In other embodiments, the electrochemical device is used in conjunction with a circuit protection board.

[0094] [Electronic Devices]

[0095] This application also provides electronic devices that include the aforementioned electrochemical apparatus. The electronic device in this application can be any electronic device, such as, but not limited to, laptops, pen-based computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, stereo headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini CDs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, automobiles, motorcycles, electric bicycles, bicycles, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries, and lithium-ion capacitors. It should be noted that the electrochemical apparatus of this application is applicable not only to the electronic devices exemplified above, but also to energy storage power stations, maritime transport vehicles, and air transport vehicles. Air transport vehicles include both air transport vehicles within the atmosphere and air transport vehicles outside the atmosphere.

[0096] The present application is further illustrated below with reference to embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present application.

[0097] The lithium-ion batteries in the following examples and comparative examples were all prepared according to the following method:

[0098] (1) Preparation of electrolyte

[0099] In an argon-atmospheric glove box with a water content of <10 ppm, ethylene carbonate (EC), propylene carbonate (PC), and diethyl carbonate (DEC) were uniformly mixed at a mass ratio of 1:1:1, and LiPF6 was added and stirred until homogeneous to form a basic electrolyte. Electrolytes were prepared according to the following examples and comparative examples, wherein the LiPF6 content was 14.4% based on the mass of the electrolyte in each example.

[0100] (2) Preparation of doped LiCoO2

[0101] The precursor compound Co(OH)2 of lithium cobalt oxide was mixed with LiOH and an oxide containing metal element M (a mixture of lanthanum oxide (La2O3), yttrium oxide (Y2O3) or niobium oxide (Nb2O5)) according to the element content ratios shown in the table below. The mixture was mixed in a high-speed mixer at 300 r / min for 20 min. The mixture was then placed in an air furnace and heated to 820℃ at 5℃ / min, maintained for 24 h, and then naturally cooled. After passing through a 300-mesh sieve, the modified positive electrode active material was obtained.

[0102] (3) Preparation of positive electrode

[0103] Lithium cobalt oxide (LiCoO2) or modified positive electrode active material (doped LiCoO2), carbon nanotubes (CNTs) as conductive agent, and polyvinylidene fluoride as a specific binder are mixed at a mass ratio of 95:2:3. N-methylpyrrolidone (NMP) is added, and the mixture is stirred under vacuum until a homogeneous positive electrode slurry is formed. The positive electrode slurry is then uniformly coated onto aluminum foil as a positive electrode current collector. After drying at 85°C, the mixture is cold-pressed, cut, and slit, and then dried under vacuum at 85°C for 4 hours to obtain the positive electrode sheet. The positive electrode active material is selected according to the following examples and comparative examples.

[0104] (4) Negative electrode preparation

[0105] The negative electrode active material graphite, the binder styrene-butadiene rubber (SBR), and the thickener sodium carboxymethyl cellulose (CMC) are thoroughly mixed in an appropriate amount of deionized water solvent at a mass ratio of 95:2:3 to form a uniform negative electrode slurry. This slurry is then coated onto the negative electrode current collector Cu foil, dried, and cold-pressed to obtain the negative electrode sheet.

[0106] (5) Preparation of the separating membrane

[0107] The separator is made of polyethylene (PE).

[0108] (6) Preparation of lithium-ion batteries

[0109] The positive electrode, separator, and negative electrode are stacked in sequence, with the separator acting as a separator between the positive and negative electrodes. Then, they are wound up and placed in an outer packaging foil. The prepared electrolyte is injected into the dried battery. After vacuum sealing, settling, formation, and shaping, the lithium-ion battery is completed.

[0110] The performance of the lithium-ion batteries in the following examples and comparative examples was then tested.

[0111] Next, the performance of the lithium-ion battery will be tested.

[0112] (1) Test method for capacity retention of lithium-ion batteries

[0113] At 25℃ / 45℃, the lithium-ion battery was charged at a constant current of 0.7C to 4.5V, then charged at a constant voltage to a current of 0.05C, and finally discharged at a constant current of 1C to 3.0V. This constituted the first cycle. The lithium-ion battery was subjected to multiple cycles under these conditions. Using the initial discharge capacity as 100%, the charge-discharge cycles were repeatedly performed until the discharge capacity decayed to 80%. The test was then stopped, and the number of cycles was recorded as an indicator of the lithium-ion battery's cycle performance.

[0114] (2) ITC performance test

[0115] At 45°C, the lithium-ion battery was charged at a constant current of 0.7C to 4.5V, and then charged at a constant voltage to a current of 0.05C. After resting for 8 hours, it was discharged at a constant current of 1C to 3.0V, and then rested for another 8 hours; this was the first cycle. The lithium-ion battery was subjected to multiple cycles under the above conditions. Using the initial discharge capacity as 100%, the charge-discharge cycles were repeatedly performed until the discharge capacity decayed to 80%. The test was then stopped, and the number of cycles was recorded as an indicator of the lithium-ion battery's cycle performance.

[0116] The specific test results are as follows:

[0117] Table 1 shows the parameters for Comparative Examples 1-1 to 1-3 and Examples 1-1 to 1-34.

[0118]

[0119]

[0120] The nitrogen atoms of the compound shown in Formula I contain lone pairs of electrons, which make it easy to complex and adsorb with transition metals and dopant ions on the positive electrode surface to form a stable interface film. This interface film can prevent the coating layer from falling off, while the skeleton support of the inorganic coating layer makes the interface film have both high mechanical strength and toughness, thus improving cycle performance.

[0121] Table 2 Parameters of Examples 1-19, Examples 2-1 to 2-18 and Comparative Example 2-1

[0122]

[0123]

[0124] As shown in Table 2, adding nitrile compounds alone deteriorates cycle performance due to side reactions at the negative electrode. However, when the compound shown in Formula I is used in combination with nitrile compounds, the compound preferentially undergoes reduction at the negative electrode to form a stable SEI, thus protecting the negative electrode interface, blocking side reactions of nitrile compounds at the negative electrode, and better protecting the positive electrode, thereby improving both room temperature and high temperature cycle performance.

[0125] Table 3 Parameters of Examples 1-19, 3-1 to 3-12

[0126]

[0127]

[0128] As shown in Table 3, the combined use of the compound shown in Formula I, nitrile compounds, and the compound shown in Formula II can improve the cycling performance at both room temperature and high temperature.

[0129] The above-described features are not intended to limit the scope of this disclosure. Therefore, any equivalent changes made to the content described in the claims of this disclosure should be included within the scope of the claims of this disclosure.

Claims

1. An electrochemical device comprising a positive electrode, a negative electrode, and an electrolyte, wherein, The positive electrode includes a positive electrode active material, which contains element A, and the element A is selected from at least one of La, Y or Nb; Based on the mass of the positive electrode active material, the mass content of element A is x%, satisfying 0.05%≤x≤2%; The electrolyte comprises a compound of formula (I) and a trinitrile compound. Equation (I) Where M is selected from at least one of formula (IA) or formula (IB): R1 is selected from substituted or unsubstituted C. 1-6 Alkyl group or substituted or unsubstituted C 2-6 Alkyl groups containing ether bonds, wherein, when substituted, the substituents are selected from fluorine atoms, C... 2-6 olefin group, C 2-6 At least one of alkynyl, cyano, sulfonyl or silyl groups; R2, R3, R4, R5, and R6 are each independently selected from hydrogen, substituted, or unsubstituted C atoms. 1-6 Alkyl, substituted or unsubstituted C 2-6 olefinic, substituted or unsubstituted C 2-6 Alkyne group, substituted or unsubstituted C 2-6 Contains an ether bond alkyl group, a fluorine atom, a cyano group or a sulfonyl group, wherein, when substituted, the substituent is selected from at least one of a fluorine atom, an aldehyde group or a cyano group; In formula (IA), R3 and R4 can be bonded to form a ring structure, and in formula (IB), R5 and R6 can be bonded to form a ring structure. Based on the mass of the electrolyte, the mass content of the compound of formula (I) is a%, and the mass content of the trinitrile compound is b%, satisfying 0.01%≤a≤2%, 0.1<x / a≤5, and 4<b / a≤8.

2. The electrochemical device according to claim 1, wherein, The compound of formula (I) is selected from at least one of the compounds represented by formulas (I-1) to (I-20): 。 3. The electrochemical device according to claim 1, wherein, It satisfies 1.5≤x / a≤3.

4. The electrochemical device according to claim 1, wherein, 0.1＜b≤5； The trinitrile compound is selected from at least one of 1,2,4-butanetrionitrile, 1,3,5-benzenetrionitrile, 2,4,6-trifluorobenzene-1,3,5-trinitrile, 2-bromobenzene-1,3,5-trinitrile, 1,3,6-hexanetrinitrile, 1,2,3-propanetrionitrile, 1,3,5-pentanetrionitrile, or 1,2,6-hexanetrionitrile.

5. The electrochemical device according to claim 1, wherein, The electrolyte further comprises a compound represented by formula (II); Formula (II) Where m is 1, 2 or 3, and A is independently selected from formula (Ⅰ-B1) or formula (Ⅰ-B2). (1-B1) (1-B2) Among them, R 11 R 12 R 13 Each is independently selected from covalent single bonds, substituted or unsubstituted C1-C6 alkylene groups, substituted or unsubstituted C2-C6 alkenyl groups, substituted or unsubstituted C2-C6 alkenyl groups. 10 The alkynyl group or substituted or unsubstituted C3-C 10 When the alicyclic hydrocarbon group is substituted, the substituent is selected from halogens; Based on the mass of the electrolyte, the content of the compound represented by formula (II) is c%, where 0.1 < c ≤ 5.

6. The electrochemical device according to claim 5, wherein, The compound of formula (II) is selected from at least one of the compounds represented by formulas (II-1) to (II-7): 。 7. The electrochemical device according to claim 1, wherein, The electrolyte further comprises a dinitrile compound; Based on the mass of the electrolyte, the mass content of the dinitrile compound is from 0.1% to 5%; The dinitrile compound is selected from at least one of malononitrile, butadionitrile, glutaronitrile, adiponitrile, octadionitrile, terephthalonitrile, tetradecanedionitrile, azomalononitrile, methyleneglutaronitrile, or pentenedionitrile.

8. The electrochemical device according to claim 5, wherein, 0.5≤b / c≤10.

9. The electrochemical device according to claim 5, wherein, 1≤b / c≤8.

3.

10. An electronic device comprising the electrochemical device according to any one of claims 1-9.

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