Electrolyte, method for preparing the same, and use thereof

Abstract

The application provides an electrolyte and a preparation method and application thereof, and relates to the technical field of secondary batteries. Specifically, the electrolyte of the application comprises an electron acceptor polymer and an electron donor polymer with specific molecular structures. The electrolyte of the application has a phase transition temperature in a wide temperature range, and charge transfer can occur between the electron donor and the electron acceptor to form a charge transfer complex. The charge transfer has high reversibility and can be regulated by temperature, so that the electrolyte exhibits temperature sensitivity. When a secondary battery is prepared by using the electrolyte of the application, the secondary battery will have good ionic conductivity of the electrolyte, low-temperature conductivity, high-temperature safety and cost-effectiveness, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of secondary batteries, in particular to an electrolyte and a preparation method and application thereof. BACKGROUND

[0002] As the core technology of modern energy storage, lithium ion batteries have dominated the market of electric vehicles, portable electronic devices and energy storage systems due to their high energy density and long cycle life. Liquid organic solvents are flammable and explosive, and can easily cause a chain exothermic reaction under high temperature, overcharge or mechanical damage, leading to battery fire or explosion; and under fast charging or low temperature environment, lithium dendrites may pierce the separator and cause short circuit, further exacerbating the risk of thermal runaway. To break through the safety bottleneck of the liquid system, solid-state batteries are considered as the next generation solution; they use non-flammable solid-state electrolytes (polymer / oxide / sulfide), which can theoretically suppress dendrites and improve energy density. However, solid-state batteries face the challenge of a significant decrease in ionic conductivity at low temperatures, which is one of the key bottlenecks restricting the application of solid-state batteries in low-temperature scenarios. For example, the ionic conductivity of sulfide solid-state electrolyte is only 0.1~0.2mS / cm at-20℃.

[0003] In view of this, the present application is proposed. SUMMARY

[0004] The first object of the present application is to provide an electrolyte, which is mainly used to solve the technical defects that high-temperature safety and low-temperature ionic conductivity performance cannot be considered; the electrolyte of the present application is in liquid state at room temperature, and is in solid state at a certain temperature, and has the advantages of both liquid electrolyte and solid electrolyte.

[0005] The second object of the present application is to provide a preparation method of the electrolyte, which is simple and easy to implement and mass production.

[0006] The third object of the present application is to provide a secondary battery.

[0007] The fourth object of the present application is to provide an electric device.

[0008] In order to achieve the above objects of the present application, the following technical solutions are adopted:

[0009] An electrolyte, comprising an electron acceptor polymer and an electron donor polymer;

[0010] The electron acceptor polymer comprises at least one of the following polymers (a)~(c):

[0011] (a); (b); (c);

[0012] The electron donor polymer includes a polymer (d) as follows:

[0013] (d);

[0014] n in the polymers (a)-(c) is independently selected from 100-1000, and m in the polymer (d) is selected from 1-10.

[0015] In an embodiment, the content of the electron acceptor polymer in the electrolyte is 3wt.%-12wt.%, and the content of the electron donor polymer in the electrolyte is 3wt.%-12wt.%.

[0016] In an embodiment, the electrolyte further includes an organic solvent.

[0017] The organic solvent includes at least one of carbonates or ethers, and / or the content of the organic solvent in the electrolyte is 65wt.%-80wt.%.

[0018] In an embodiment, the electrolyte further includes a lithium salt.

[0019] The lithium salt includes at least one of LiPF6, LiBF4, LiFSI, LiTFSI, LiClO4, LiAsF6, LiBOB, LiDFOB, and / or the content of the lithium salt in the electrolyte is 8wt.%-18wt.%.

[0020] In an embodiment, the electrolyte further includes an additive.

[0021] The additive includes at least one of 1,2-dimethoxybenzene, 2,5-oxazolidinedione, N,N-dimethyltrifluoroacetamide, 2,3,5,6-tetrafluorop-phenyldiazine, N,N-diethyltrimethylsilylamine, and / or the content of the additive in the electrolyte is 2wt.%-4wt.%.

[0022] In an embodiment, the phase transition temperature of the electrolyte is 20℃-70℃.

[0023] A preparation method of the electrolyte includes: mixing the components of the electrolyte sufficiently to obtain the electrolyte.

[0024] A secondary battery includes the electrolyte.

[0025] In an embodiment, the secondary battery is a lithium ion battery.

[0026] The positive electrode of the lithium ion battery comprises one of lithium iron phosphate, lithium cobaltate, lithium manganese oxide, lithium nickel oxide or a ternary material, and the negative electrode comprises one of graphite, silicon, silicon-carbon composite material or metallic lithium.

[0027] An electric device comprising the secondary battery.

[0028] The present application provides a wide temperature range temperature phase change electrolyte, charge transfer can occur between electron donor and electron acceptor, forming charge transfer complex, and the charge transfer has high reversibility, which can be regulated by temperature, so that the electrolyte exhibits temperature sensitive characteristics. Specifically, when in a lower ambient temperature, the electrolyte shows liquid state, as the temperature rises, the charge transfer disappears, the electron donor / acceptor polymer is insoluble in the electrolyte, precipitates from the solution and wraps other components of the electrolyte, and the whole electrolyte is in solid state, with high temperature safety and stability.

[0029] Compared with the prior art, the present application has the following advantages:

[0030] (1) High low-temperature conductivity: by adjusting the content of electron donor / acceptor polymer, the content of lithium salt, the type and content of additives, the electrolyte of the present application can achieve high ionic conductivity at low temperature, which is 5~10 times of conventional sulfide solid electrolyte.

[0031] (2) High temperature safety: when the lithium battery using the electrolyte of the present application is in normal working temperature range of 20℃ to 30℃, the electrolyte is in liquid state; when the battery temperature rises, the electrolyte undergoes phase change and becomes solid state, improving the high temperature safety.

[0032] (3) Low cost: the existing temperature phase change electrolyte usually uses ionic liquid as carrier, which has high cost, for example, the cost of imidazole ionic liquid is as high as 500~1500 yuan / kg; compared with ionic liquid, the present application uses low-cost organic solvent to realize the phase change of electrolyte in a wide temperature range of 20℃~70℃, which has much lower cost than ionic liquid under the condition of similar performance. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0034] Figure 1 The discharge capacity performance comparison chart in the test example of the present application is provided. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be described clearly and completely in combination with the drawings and specific embodiments below, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present application, not all the embodiments, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. The specific conditions are not specified in the embodiments, and are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, and are conventional products that can be obtained by market purchase. In addition, the terms "first", "second", "third" are only used for description purposes, and cannot be understood as indicating or implying relative importance.

[0036] The first aspect of the present application is to provide an electrolyte mainly comprising an electron acceptor polymer and an electron donor polymer.

[0037] The electron acceptor polymer of the present application comprises at least one of the following polymers (a)~(c):

[0038] (a); (b); (c);

[0039] The electron donor polymer of the present application comprises the following polymer (d):

[0040] (d);

[0041] and n in polymers (a)~(c) is independently selected from 100~1000, and m in polymer (d) is selected from 1~10.

[0042] A temperature-sensitive electrolyte with a wide temperature range phase transition temperature is provided in the present application; when the electrolyte of the present application is used, the battery can achieve high ionic conductivity at low temperature while having high temperature safety.

[0043] The present application adds two types of polymers to the electrolyte, one as an electron donor and the other as an electron acceptor. Charge transfer can occur between the two types of polymers to form a charge transfer complex (CTC); and the charge transfer has high reversibility and can be controlled by temperature, so that the electrolyte exhibits temperature-sensitive characteristics. When the temperature is low, the electrolyte is in a liquid state, and as the temperature rises, the charge transfer disappears, the polymer is insoluble in the electrolyte, and precipitates from the solution, encapsulating other components of the electrolyte, and the entire electrolyte is in a solid state, with high temperature safety and stability.

[0044] As an optional embodiment, the value of n in the polymers (a)-(c) is independently selected, including but not limited to any one of 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000 or a numerical interval formed by any two of them.

[0045] As an optional embodiment, the value of m in the polymer (d) includes but is not limited to any one of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or a numerical interval formed by any two of them.

[0046] As a preferred embodiment, the content of the electron acceptor polymer in the electrolyte is 3wt.%-12wt.%, including but not limited to any one of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 (wt.%) or a numerical interval formed by any two of them.

[0047] As a preferred embodiment, the content of the electron donor polymer in the electrolyte is 3wt.%-12wt.%, including but not limited to any one of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 (wt.%) or a numerical interval formed by any two of them.

[0048] As a preferred embodiment, the content of the electron acceptor polymer and the electron donor polymer is the same.

[0049] As a preferred embodiment, the electrolyte further includes an organic solvent, which includes at least one of a carbonate compound or an ether compound; in some optional embodiments, the carbonate compound includes but is not limited to at least one of ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), or propylene carbonate (PC), and the ether compound includes but is not limited to at least one of dimethoxy methane, 1,2-dimethoxy ethane, 1,2-dimethoxy propane, diethylene glycol dimethyl ether, etc.

[0050] As a more preferred embodiment, the content of the organic solvent in the electrolyte is 65wt.%-80wt.%, including but not limited to any one of 65, 68, 70, 72, 75, 78, 80, 82, 85 (wt.%) or a numerical interval formed by any two of them.

[0051] As a preferred embodiment, the electrolyte further comprises a lithium salt, the lithium salt comprising at least one of LiPF6, LiBF4, LiFSI, LiTFSI, LiClO4, LiAsF6, LiBOB, LiDFOB.

[0052] As a more preferred embodiment, the content of the lithium salt in the electrolyte is 8wt.%~18wt.%, including but not limited to any one of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 (wt.%), or a numerical interval composed of any two of them.

[0053] As a preferred embodiment, the electrolyte further comprises an additive; the additive comprising at least one of 1,2-dimethoxybenzene, 2,5-oxazolidinedione, N,N-dimethyl trifluoroacetamide, 2,3,5,6-tetrafluoro-p-diazine, N,N-diethyl trimethyl silyl amine.

[0054] As a more preferred embodiment, the content of the additive in the electrolyte is 2wt.%~4wt.%, including but not limited to any one of 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4 (wt.%), or a numerical interval composed of any two of them.

[0055] As a preferred embodiment, the phase transition temperature of the electrolyte is 20℃~70℃. It is worth noting that the phase transition temperature refers to the transition temperature of the electrolyte from liquid to solid. In the present application, the phase transition temperature is affected by many factors such as component composition and weight ratio, and the specific phase transition temperature of the electrolyte can be customized by the skilled person in the art under the adjustment of the above preferred features. Further, the electrolyte material of the present application can realize phase transition in a wide temperature range, and the phase transition temperature can be adjusted by changing the addition amount and proportion of the electron donor and / or the electron acceptor; specifically, when the electron donor is more, the competition between the electron donors is enhanced, which weakens the charge transfer between the electron donor and the electron acceptor, and lowers the phase transition temperature.

[0056] As a preferred embodiment, the synthesis route of the electron acceptor polymer comprises: mixing a first monomer, a second monomer, one of triethylamine or pyridine, a reaction solvent, and then stirring the reaction at 20℃~30℃ for 3h~5h; after the reaction is completed, the excess first monomer is removed by reduced pressure distillation, and then the precursor of the electron acceptor polymer is obtained after water washing, extraction, and drying.

[0057] wherein, the first monomer is when the electron acceptor polymer is polymer (a), the second monomer is ; when the electron acceptor polymer is polymer (b), the second monomer is ; when the electron acceptor polymer is polymer (c), the second monomer is ;

[0058] Further, when the electron acceptor polymer is polymer (a), the precursor is ; when the electron acceptor polymer is polymer (b), the precursor is ; when the electron acceptor polymer is polymer (c), the precursor is ;

[0059] As an optional embodiment, the extraction employs ether as the extractant, and after the extraction, the ether phase is separated to perform the subsequent drying; the drying employs vacuum drying, the temperature is 60℃~80℃, and the time length is 4h~6h.

[0060] As a more preferred embodiment, the molar ratio of the first monomer and the second monomer is 3:1, and the reaction solvent is DMF and DMSO.

[0061] Further, for the above synthesis route, the preparation of the electron acceptor polymer from the precursor includes the following steps: stirring and reacting the precursor, an initiator, and a second reaction solvent at 60℃~100℃ for 1h~3h, after the reaction is completed, precipitating and separating the reaction system in a poor solvent, and then drying and obtaining the electron acceptor polymer.

[0062] As an optional embodiment, the drying employs vacuum drying, the temperature is 80℃~100℃, and the time length is 6h~10h.

[0063] As a more preferred embodiment, the molar ratio of the precursor and the initiator is 100:1~200:1, the molar ratio of the precursor and the second reaction solvent is 1:10~1:5, the initiator includes at least one of azobisisobutyronitrile (AIBN), azobisisoheptyl nitrile (ABVN), and dibenzoyl peroxide (BPO), the second reaction solvent includes at least one of toluene or ethyl acetate, and the poor solvent includes methanol.

[0064] In addition, when the electron donor polymer is polymer (d), it can be purchased through a commercial channel, or can be prepared through a conventional synthesis route in the art, and is not strictly limited in the present application.

[0065] The second aspect of the present application is to provide a preparation method of the electrolyte as described in the first aspect, mainly including the following steps: fully mixing the components of the electrolyte to obtain the electrolyte.

[0066] As a preferred embodiment, the electron acceptor polymer, the electron donor polymer, the lithium salt, the additive and the organic solvent are mixed sufficiently to obtain the electrolyte.

[0067] As an optional embodiment, the mixing can be assisted by oscillation, stirring, shaking, centrifugation, ultrasonic, heating and the like, which helps to accelerate the dispersion and obtain a relatively uniform dispersion system.

[0068] The third aspect of the present application provides a secondary battery comprising the electrolyte according to the second aspect.

[0069] As a preferred embodiment, the secondary battery is a lithium ion battery.

[0070] As a more preferred embodiment, the positive electrode of the lithium ion battery comprises one of lithium iron phosphate, lithium cobaltate, lithium manganese oxide, lithium nickel oxide or a ternary material, and the negative electrode comprises one of graphite, silicon, silicon-carbon composite material or metallic lithium. In some optional embodiments, the separator of the lithium ion battery comprises one of polyethylene, polypropylene, polyimide, polyamide, polyvinylidene fluoride or polytetrafluoroethylene.

[0071] The fourth aspect of the present application provides an electrical equipment comprising the secondary battery according to the third aspect.

[0072] It can be understood that the electrical equipment can be any equipment or device that relies on electrical energy for operation or running, including but not limited to new energy vehicles, building electrical equipment, industrial electrical equipment, household and agricultural electrical equipment, etc. When comprising the secondary battery, any electrical equipment equipped with the secondary battery can belong to an embodiment of the present application.

[0073] Example 1

[0074] S1, synthesis of polymer (b):

[0075] The first monomer, the second monomer, triethylamine and a solvent (DMF) were added to a nitrogen-purged three-necked flask equipped with a condenser, the molar ratio of the first monomer to the second monomer was 3:1, the reaction system was stirred at 25℃ for 4 hours, after the reaction was completed, the excess first monomer was removed by vacuum distillation, the obtained reaction system was washed with water, extracted with diethyl ether, and the diethyl ether phase was vacuum dried at 70℃ for 5 hours to obtain a precursor;

[0076] The first monomer is: The second monomer is: The precursor is: ;

[0077] Then the above precursor, initiator (AIBN), reaction solvent (ethyl acetate) are added into a three-neck flask purged with nitrogen and equipped with a condenser, the reaction system is stirred at 80°C for 2 hours, the obtained polymer is precipitated in a poor solvent and vacuum dried at 90°C for 8 hours, to obtain a polymer corresponding to the following structural formula (b); wherein, in this example, the molar ratio of the precursor to the initiator is 100:1, and the molar ratio of the precursor to the reaction solvent is 1:5.

[0078] S2, in an argon-filled glove box, 69wt.% dimethoxymethane, 15wt.% LiBF4, 7wt.% polymer corresponding to the following structural formula (b), 7wt.% polymer corresponding to the following structural formula (d), 0.5wt.% 1,2-dimethoxybenzene, 1.5wt.% N,N-diethyltrimethylsilylamine are mixed and placed on a stirring device to stir at 800 rpm for 30 min to obtain the electrolyte of this example.

[0079] (b), n = 550;

[0080] (d), m = 6.

[0081] Example 2

[0082] S1, basically the same as step S1 of example 1, the only difference is that:

[0083] The second monomer is: ;

[0084] The precursor is: ;

[0085] And in this example, the reaction stage of the precursor, initiator and reaction solvent, the reaction system is stirred at 80°C for 3 hours.

[0086] S2, in an argon-filled glove box, 68wt.% dimethoxyethane, 10wt.% LiTFSI, 5wt.% LiDFOB, 8wt.% polymer corresponding to the following structural formula (a), 6wt.% polymer corresponding to the following structural formula (d), 1wt.% 1,2-dimethoxybenzene, 1wt.% N,N-dimethyltrifluoroacetamide, 1wt.% 2,3,5,6-tetrafluoro-p-diazine are mixed and placed on a stirring device to stir at 800 rpm for 30 min to obtain the electrolyte of this example.

[0087] (a), n = 750;

[0088] (d), m = 7.

[0089] Example 3

[0090] S1, substantially the same as step S1 of Example 2, the only difference being that:

[0091] In this example, the molar ratio of the precursor to the initiator is 200:1, and the molar ratio of the precursor to the reaction solvent is 1:10;

[0092] S2, in an argon-filled glove box, 72wt.% dimethoxymethane, 12wt.% LiBOB, 6wt.% polymer corresponding to the following structural formula (a), 8wt.% polymer corresponding to the following structural formula (d), 1.2wt.% 1,2-dimethoxybenzene, 0.8wt.% N,N-dimethyl trifluoroacetamide were mixed and placed on a stirring device for stirring at 800 rpm for 30 min to obtain the electrolyte of this example.

[0093] (a), n = 650;

[0094] (d), m = 7.

[0095] Example 4

[0096] S1, substantially the same as step S1 of Example 1, the only difference being that:

[0097] The second monomer is: ;

[0098] The precursor is: ;

[0099] and in this example, the molar ratio of the precursor to the initiator is 200:1, and the molar ratio of the precursor to the reaction solvent is 1:10; during the reaction stage of the precursor, the initiator and the reaction solvent, the reaction system was stirred at 80°C for 1 hour;

[0100] S2, in an argon-filled glove box, 76wt.% diethyleneglycol dimethyl ether, 5wt.% LiPF6, 5wt.% LiBF4, 8wt.% polymer corresponding to the following structural formula (c), 5wt.% polymer corresponding to the following structural formula (d), 0.6wt.% 1,2-dimethoxybenzene, 0.4wt.% 2,5-oxazolidinedione were mixed and placed on a stirring device for stirring at 800 rpm for 30 min to obtain the electrolyte of this example.

[0101] (c), n = 350;

[0102] (d), m = 5.

[0103] Example 5

[0104] S1, substantially the same as Example 4, with the only difference being that:

[0105] In this example, the molar ratio of the precursor to the initiator is 100:1, and the molar ratio of the precursor to the reaction solvent is 1:5; in the reaction stage of the precursor, the initiator and the reaction solvent, the reaction system is stirred at 80°C for 2 hours;

[0106] S2, in an argon-filled glove box, 71 wt.% 1,2-dimethoxypropane, 12 wt.% LiPF6, 4 wt.% polymer corresponding to the following structural formula (c), 9 wt.% polymer corresponding to the following structural formula (d), 2 wt.% N,N-diethyltrimethylsilylamine, 2 wt.% 2,5-oxazolidinedione are mixed, placed on a stirring device to stir at 800 rpm for 30 min to obtain the electrolyte of this example.

[0107] (c), n = 550;

[0108] (d), m = 3.

[0109] Comparative Example 1

[0110] In an argon-filled glove box, 74 wt.% 1,2-dimethoxyethane, 10 wt.% LiTFSI, 5 wt.% LiDFOB, 8 wt.% polymer corresponding to the following structural formula (a), 1 wt.% 1,2-dimethoxybenzene, 1 wt.% N,N-dimethyltrifluoroacetamide, 1 wt.% 2,3,5,6-tetrafluoro-p-diazine are mixed, placed on a stirring device to stir at 800 rpm for 30 min to obtain the electrolyte of this comparative example.

[0111] (a), n = 750.

[0112] Comparative Example 2

[0113] In an argon-filled glove box, 78 wt.% dimethoxymethane, 12 wt.% LiBOB, 8 wt.% polymer corresponding to the following structural formula (d), 1.2 wt.% 1,2-dimethoxybenzene, 0.8 wt.% N,N-dimethyltrifluoroacetamide are mixed, placed on a stirring device to stir at 800 rpm for 30 min to obtain the electrolyte of this comparative example.

[0114] (d), m = 7.

[0115] Comparative Example 3

[0116] In an argon-filled glove box, 76 wt.% 1,2-dimethoxypropane, 5 wt.% LiPF6, 8 wt.% polymer corresponding to the following structural formula (c), 5 wt.% polymer corresponding to the following structural formula (e), 0.6 wt.% 1,2-dimethoxybenzene, 0.4 wt.% 2,5-oxazolidinedione were mixed and placed on a stirring device to stir at 800 rpm for 30 min to obtain the electrolyte of the present comparative example.

[0117] (c), n = 350;

[0118] (e).

[0119] Test Example

[0120] (1) Ion conductivity test: 2 cm 2 The stainless steel gasket and the electrolyte were assembled into a battery, the battery was placed in a low temperature test box at -20°C for 3 h, and then connected to an electrochemical workstation, the electrochemical workstation applied a sinusoidal voltage signal with an amplitude of 20 mV, the test frequency range was between 4 MHz and 100 MHz, the resistance of the electrolyte was recorded, and the ion conductivity was calculated.

[0121] (2) Discharge capacity test: the electrolytes obtained in each example and comparative example were prepared into test batteries; specifically, lithium iron phosphate was used as the positive electrode, metal lithium was used as the negative electrode, and polyvinylidene fluoride was used as the separator, which was assembled into a battery shell to obtain lithium batteries corresponding to each example.

[0122] The assembled batteries were placed in a high and low temperature test box, the temperature was set to 25°C, and the batteries were left to stand for 1 hour; then a charge-discharge instrument was connected, and the batteries were discharged at a rate of 0.2C, with a discharge cut-off voltage of 2V, the capacity of the first discharge at 25°C was recorded (corresponding to the capacity value at cycle number 1 in Figure 1 ), and the value was recorded in Table 1. The battery was placed in a temperature box, the temperature box was raised from the test environment temperature to 75°C at a rate of 5°C / min, and maintained at this temperature for 30 min; then the temperature box was cooled to 25°C at a rate of 1°C / min, and maintained at this temperature for 30 min, and then discharged at a rate of 0.2C, with a discharge cut-off voltage of 2V, the discharge capacity was recorded (corresponding to the capacity value at cycle number 2 in Figure 1 ). The above steps were repeated until 5 cycles were generated, and the results were plotted to obtain the capacity performance graph shown in Figure 1 .

[0123] (3) Phase transition temperature test: The phase transition temperature of the electrolyte is determined by measuring the transmittance of the electrolyte solution; the transmittance of the electrolyte solution is determined using a variable temperature UV-visible spectrometer; the solution is placed on the heating table of the instrument, the solution is heated at a heating rate of 1℃ / min, the transmittance curve is recorded, and the temperature at which the transmittance reaches 0 is defined as the phase transition temperature.

[0124] The results of the above tests (1) to (3) are recorded in Table 1 below.

[0125] Table 1

[0126]

[0127] Although the present application has been illustrated and described with reference to specific embodiments, it is to be understood that the above-mentioned embodiments are merely used to illustrate the technical solutions of the present application, and are not intended to limit the present application; it should be understood by those skilled in the art that the technical solutions recorded in the above-mentioned embodiments can be modified, or some or all of the technical features can be replaced equivalently, without departing from the spirit and scope of the present application; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application; therefore, this means that all these replacements and modifications within the scope of the present application are included in the appended claims.

Claims

1. An electrolyte, characterized by, The electrolyte comprises an electron acceptor polymer and an electron donor polymer; The electron acceptor polymer comprises at least one of the following polymers (a)-(c): (a); (b); (c); The electron donor polymer comprises the following polymer (d): （d）； And in the polymers (a)-(c), n is independently selected from 100-1000, and in the polymer (d), m is selected from 1-10.

2. The electrolyte according to claim 1, characterized in that, In the electrolyte, the content of the electron acceptor polymer is 3wt.%-12wt.%, and the content of the electron donor polymer is 3wt.%-12wt.%.

3. The electrolyte of claim 1, wherein The electrolyte further comprises an organic solvent; The organic solvent comprises at least one of carbonates or ethers, and / or, in the electrolyte, the content of the organic solvent is 65wt.%-80wt.%.

4. The electrolyte of claim 1, wherein The electrolyte further comprises a lithium salt; The lithium salt comprises at least one of LiPF6, LiBF4, LiFSI, LiTFSI, LiClO4, LiAsF6, LiBOB, LiDFOB, and / or, in the electrolyte, the content of the lithium salt is 8wt.%-18wt.%.

5. The electrolyte of claim 1, wherein The electrolyte further comprises an additive; The additive comprises at least one of 1,2-dimethoxybenzene, 2,5-oxazolidinedione, N,N-dimethyltrifluoroacetamide, 2,3,5,6-tetrafluorop-phenylene diamine, N,N-diethyltrimethylsilylamine, and / or, in the electrolyte, the content of the additive is 2wt.%-4wt.%.

6. The electrolyte of claim 1, wherein The phase transition temperature of the electrolyte is 20℃-70℃.

7. The method of producing an electrolyte according to any one of claims 1 to 6, wherein Comprising: The composition components of the electrolyte are mixed sufficiently to obtain the electrolyte.

8. A secondary battery characterized by comprising: The electrolyte according to any one of claims 1-6.

9. The secondary battery according to claim 8, characterized by The secondary battery is a lithium ion battery; The positive electrode of the lithium ion battery comprises one of lithium iron phosphate, lithium cobaltate, lithium manganese oxide, lithium nickel oxide or ternary material, and the negative electrode comprises one of graphite, silicon, silicon-carbon composite material or metal lithium.

10. An electric device, characterized by The secondary battery according to claim 8.

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