High-rate lithium-carbon fluoride battery electrolyte containing Lewis acid additive and application of high-rate lithium-carbon fluoride battery electrolyte

Abstract

The invention discloses a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acid additive as well as a preparation method and application of the high-rate lithium-carbon fluoride battery electrolyte, and belongs to the technical field of lithium primary batteries. 0.005-0.1 mol / L of Lewis acid additive is added into the electrolyte of the lithium-carbon fluoride battery, and the strong attraction force of electron-deficient atom centers of the Lewis acid additive to electron-rich fluorine ions is utilized, so that LiF is subjected to coordination dissociation, the dissociation energy is remarkably reduced, a solvated coordination compound is formed, and free Li < + > is released. Compared with the traditional solid-phase reaction, the Lewis acid additive in the electrolyte can react with the discharge product to promote the generation of LiF in the liquid phase, so that the discharge voltage platform is greatly improved, the initial voltage hysteresis phenomenon is delayed, and the discharge capacity of the lithium-carbon fluoride battery at high rate is also improved. In addition, the electrolyte additive is low in cost and easy to prepare, and large-scale production can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of primary lithium batteries, and particularly relates to a high-rate lithium-carbon monofluoride battery electrolyte containing a Lewis acidic additive and its application. Background Art

[0002] The primary lithium-carbon monofluoride battery exhibits excellent performance advantages due to its stable discharge platform, extremely long storage life, wide operating temperature range, and extensive application fields. As the system with the highest energy density of the positive electrode material in primary lithium metal batteries, its theoretical energy density reaches 2180 Wh / kg, and the theoretical specific capacity is 865 mAh / g, far exceeding that of lithium-thionyl chloride batteries (1470 Wh / kg) and lithium-manganese dioxide batteries (1005 Wh / kg). In addition, due to the excellent chemical stability of carbon monofluoride, the annual self-discharge rate of this battery is extremely low, ensuring that its storage life can exceed 10 years. These characteristics make the lithium-carbon monofluoride battery an ideal power source in special or extreme environments, and it is widely used in high-tech fields such as medical, aerospace, and military, and is an important power solution that cannot be replaced at present.

[0003] However, with the increasing demand for high specific energy primary batteries in various fields, the lithium-carbon monofluoride battery has attracted much attention, but there are still many challenges in further improving its rate performance. Specifically, the main factor limiting the rate performance lies in the poor electron transport performance of the carbon monofluoride material. To achieve high energy density, carbon monofluoride materials with a high degree of fluorination are usually selected, but the higher the degree of fluorination, the lower its electron transport performance, which has a significant impact on the rate performance. In the traditional electrolyte system, due to the poor conductivity of the carbon monofluoride material itself, the insulating discharge product lithium fluoride (LiF) is difficult to dissolve, and its crystallization and precipitation rate increases with the increase of the discharge rate. This not only further exacerbates the voltage hysteresis phenomenon of the primary lithium-carbon monofluoride battery, but also increases the polarization degree of the battery, resulting in a significant decrease in the utilization rate of the active material, thus causing the actual discharge capacity of the battery to decay at high rates and weakening the actual energy output of the battery. In addition, the deposition of lithium fluoride will also cause an increase in the internal resistance and heat generation of the battery, severely limiting the application of the primary lithium-carbon monofluoride battery at high rates.

[0004] To overcome the above bottlenecks, current researchers have explored many innovative strategies. For example, optimizing the positive electrode material: improving the selection of carbon source and fluorine source, and optimizing the preparation process of the carbon monofluoride positive electrode material to increase the proportion of electrochemically active C-F bonds; improving the electrolyte formula: introducing an electrolyte solvent with a weak solvation effect to increase the discharge voltage platform of the battery; modifying the negative electrode: modifying the lithium metal negative electrode to improve its interfacial stability with the electrolyte and enhance the comprehensive performance of the battery.

[0005] Although the above measures have alleviated the problem of improving the rate performance to a certain extent, with the continuous improvement of application requirements, these solutions are still insufficient. Therefore, there is an urgent need for more breakthrough solutions to further improve the rate performance of lithium-carbon fluoride batteries.

[0006] Based on this, the present invention focuses on developing a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. By innovating the electrolyte formulation, the present invention aims to effectively alleviate the polarization problem caused by the deposition of discharge product LiF, improve the utilization rate of active materials of carbon fluoride materials at high rates, and at the same time optimize the electrolyte channel structure to improve the ion transport rate, thereby significantly enhancing the rate performance and energy output efficiency of the battery and meeting the requirements of high-rate application scenarios. Summary of the Invention

[0007] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the specification of this application, to avoid obscuring the purpose of this part, the abstract of the specification, and the title of the invention, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0008] In view of the above and / or problems existing in the prior art, the present invention is proposed.

[0009] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive.

[0010] To solve the above technical problems, the present invention provides the following technical solutions:

[0011] The electrolyte is composed of a Lewis acidic additive, a lithium salt, and a solvent;

[0012] Among them, the Lewis acidic additive includes one or more of boric acid, boric acid derivatives, aluminum salts, and arsenic-based additives; the concentration of the Lewis acidic additive relative to the electrolyte is 0.005 - 0.1 mol / L;

[0013] The boric acid derivatives include boron trifluoride, triethyl borate, tris(trimethylsilyl) borate, tris(hexafluoroisopropyl) borate, triphenyl borate, tris(pentafluorophenyl) borane; the aluminum salts include aluminum chloride, aluminum acetate; the arsenic-based additive includes lithium hexafluoroarsenate.

[0014] As a preferred embodiment of the high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive according to the present invention, wherein: the solvent includes one or more of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, dimethyl sulfite, ethylene glycol dimethyl ether, dimethyl sulfoxide, tetraethylene glycol dimethyl ether, tetrahydrofuran, sulfolane, methyl phenyl sulfone, 1,3-dioxolane, and acetonitrile; the lithium salt includes one or more of LiBF4, LiPF6, LiBOB, LiTFSI, LiFSI, and LiClO4.

[0015] As a preferred embodiment of the high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive according to the present invention, wherein: the concentration of the lithium salt is 0.5 to 5 mol / L.

[0016] Another object of the present invention is to overcome the deficiencies in the prior art and provide an application of a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive in the preparation of a lithium-carbon fluoride battery.

[0017] Yet another object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a lithium-carbon fluoride battery.

[0018] To solve the above technical problems, the present invention provides the following technical solutions:

[0019] In a glove box under a high-purity argon atmosphere, a lithium sheet is used as the negative electrode, a carbon fluoride electrode sheet is used as the positive electrode, and a PP or PE membrane is used as the separator;

[0020] After standing the electrolyte described in claim 1 for 12 to 20 hours, 80 to 100 μL of it is injected into the battery, and the battery is assembled.

[0021] As a preferred embodiment of the method for preparing a lithium-carbon fluoride battery according to the present invention, wherein: the method for preparing the carbon fluoride electrode sheet includes,

[0022] Mixing carbon fluoride powder, conductive carbon, and a binder in a mass ratio of 80 to 86:16 to 10:4, and uniformly dispersing them in an N-methylpyrrolidone solvent to form a uniform slurry;

[0023] Using a scraper to uniformly coat the slurry on the current collector, controlling the surface density to be 1 to 20 mg / cm 2 ;

[0024] Drying the current collector coated with the slurry, and then using a punching machine to cut the dried carbon fluoride electrode sheet into carbon fluoride electrode sheets with a diameter of 10 to 12 mm.

[0025] As a preferred embodiment of the preparation method of the lithium-carbon fluoride battery of the present invention, wherein: the conductive carbon includes one or more of Super P, acetylene black, carbon black, carbon nanotubes, graphene, and Ketjen black.

[0026] As a preferred embodiment of the preparation method of the lithium-carbon fluoride battery of the present invention, wherein: the binder includes one or more of polyvinylidene fluoride and sodium alginate.

[0027] Another object of the present invention is to overcome the deficiencies in the prior art and provide a lithium-carbon fluoride battery prepared by the preparation method of the lithium-carbon fluoride battery.

[0028] As a preferred embodiment of the lithium-carbon fluoride battery of the present invention, wherein: the lithium-carbon fluoride battery has the following characteristics

[0029] When discharging to 1.5V at a discharge current of 2C using a Lanhe tester CT2001A, the specific capacity of the lithium-carbon fluoride battery is 690-780 mA / g, and the discharge voltage is maintained at 2.65-2.8V at this time.

[0030] Advantages of the present invention:

[0031] (1) By introducing a Lewis acidic additive and utilizing its Lewis acidity, the solubility of the discharge product lithium fluoride is increased, the discharge voltage of the lithium-carbon fluoride battery is significantly improved at high rates, and the phenomenon of discharge voltage hysteresis is effectively improved. At the same time, the Lewis acidic additive can also participate in the discharge process, promote the formation of LiF in the liquid phase, improve the ion transport rate, and reduce the battery polarization degree, thereby significantly improving the discharge capacity of the lithium-carbon fluoride battery at high rates. In addition, the Lewis acidic additive can also coordinate with solvent molecules, reduce the reduction activity of the solvent, and reduce side reactions;

[0032] (2) By optimizing the electrolyte composition, not only the discharge capacity of the lithium-carbon fluoride battery at high rates is improved, the battery rate performance is improved, but also the problem of voltage hysteresis is solved, and because the Lewis acidic additive has a wide source and is easy to prepare, it provides the possibility for large-scale production. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts. Among them:

[0034] Figure 1Morphology diagram of the positive electrode discharge product of the lithium-carbon fluoride battery containing the electrolyte of Example 1 in the present invention;

[0035] Figure 2 Morphology diagram of the positive electrode discharge product of the lithium-carbon fluoride battery containing the electrolyte of Comparative Example 1 in the present invention;

[0036] Figure 3 Voltage-discharge specific capacity curve diagram of the lithium-carbon fluoride battery containing the electrolytes of Comparative Example 1 and Example 1 in the present invention. Detailed implementation manners

[0037] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention in conjunction with the embodiments of the specification.

[0038] Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0039] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or alternative embodiment that is mutually exclusive with other embodiments.

[0040] The raw materials used in the present invention are commercially available without special instructions.

[0041] The method for testing the electrochemical performance of the materials in the present invention is as follows: Mix carbon fluoride powder, conductive carbon black, and polyvinylidene fluoride (PVDF) in a mass ratio of 80:16:4, then add them to N-methylpyrrolidone solvent and disperse evenly to form a slurry. Subsequently, use a scraper to scrape the slurry on the current collector, controlling the surface density to be 1-20 mg / cm 2 . After scraping, place the electrode sheet in an oven to dry. Use a punching machine to cut the dried electrode sheet into electrode sheets with a diameter. In a glove box filled with argon, use a lithium sheet as the negative electrode, a PP membrane as the separator, inject 80-100 μL of electrolyte, and assemble a button battery. After standing for 12-20 h, use a Blue Electric Tester CT2001A to discharge to 1.5 V at a discharge current of 2C and record the data.

[0042] Example 1

[0043] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acid additive. The electrolyte is composed of triethyl borate, lithium tetrafluoroborate (LiBF4), and a mixed solvent of propylene carbonate and ethylene glycol dimethyl ether with a volume ratio of 1:1. Among them, the concentration of triethyl borate is 0.05 mol / L, and the concentration of LiBF4 is 1 mol / L.

[0044] Comparative Example 1

[0045] This comparative example provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acid additive. The difference from Example 1 is that it does not contain triethyl borate, and the other components are the same as those in Example 1, obtaining an electrolyte without a Lewis acid additive.

[0046] The electrolytes of Example 1 and Comparative Example 1 were used to prepare lithium-carbon fluoride batteries, and the morphology of the positive electrode after discharging the batteries was tested. The results are as Figures 1-2 shown.

[0047] Comparing Figure 1 , 2 , it can be clearly observed that there are significant differences in the morphology of the positive electrode after discharging. When triethyl borate is added as a Lewis acid additive to prepare the electrolyte, the size of lithium fluoride particles is significantly smaller, and the cracking phenomenon of the carbon fluoride layer is more obvious. This structural change helps to expose more active substances, thus promoting the full progress of the electrochemical reaction and improving the rate performance of the battery.

[0048] The electrolytes obtained in Example 1 and Comparative Example 1 were used to prepare lithium-carbon fluoride batteries, and the electrochemical performance of the batteries was tested. The results are as Figure 3 and Table 1 show.

[0049] Table 1 Influence of the presence or absence of a Lewis acid additive on battery performance

[0050]

[0051] According to Table 1 and Figure 3 it can be obtained that under the discharge current condition of 2C, the lithium-carbon fluoride battery prepared with the electrolyte containing a Lewis acid additive exhibits a discharge voltage and discharge specific capacity significantly higher than those of the battery without adding any Lewis acid additive. This shows that such a Lewis acid additive, as an additive for the lithium-carbon fluoride battery electrolyte, can not only significantly improve the discharge capacity of the primary lithium-carbon fluoride battery at high rates but also maintain a relatively high discharge voltage, to a certain extent solving the problem of voltage hysteresis of the lithium-carbon fluoride battery. This is because the Lewis acid additive can promote the formation of LiF in the liquid phase and at the same time slow down the accumulation of the inert product LiF on the surface of the positive electrode.

[0052] Example 2

[0053] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that the concentration of triethyl borate is adjusted to 0.01 mol / L, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0054] Embodiment 3

[0055] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that the concentration of triethyl borate is adjusted to 0.075 mol / L, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0056] Embodiment 4

[0057] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that the concentration of triethyl borate is adjusted to 0.1 mol / L, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0058] The electrolytes obtained in Embodiments 2 to 4 are used to prepare lithium-carbon fluoride batteries, and the electrochemical performance of the batteries is tested. The results are shown in Table 2.

[0059] Table 2 Influence of the concentration of Lewis acidic additive on battery performance

[0060]

[0061] Comparing the performance parameters of the batteries corresponding to different concentrations of Lewis acidic additives in Table 2, it can be seen that as the concentration of the Lewis acidic additive increases, the specific capacity of the corresponding battery does not always increase. This may be related to the fact that an excessive amount of Lewis acidic additive affects the lithium ion solvation process in the electrolyte. Among them, when the concentration of the Lewis acidic additive is 0.05 mol / L, the discharge capacity of the corresponding lithium-carbon fluoride battery is the largest, reaching 772.0 mAh / g, and the discharge voltage can be maintained at 2.76 V at this time, with the best overall effect.

[0062] Embodiment 5

[0063] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that the Lewis acidic additive triethyl borate is adjusted to triphenyl borate, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0064] Embodiment 6

[0065] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that triethyl borate as the Lewis acidic additive is adjusted to lithium hexafluoroarsenate, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0066] Embodiment 7

[0067] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that triethyl borate as the Lewis acidic additive is adjusted to aluminum acetate, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0068] The electrolytes obtained in Embodiments 5 to 7 are used to prepare lithium-carbon fluoride batteries, and the electrochemical performances of the batteries are tested. The results are shown in Table 3.

[0069] Table 3 Influence of the type of Lewis acidic additive on battery performance

[0070]

[0071] It can be seen from the data in Table 3 that the type of Lewis acidic additive has a significant influence on the performance of the prepared lithium-carbon fluoride battery, which is determined by the Lewis acidity of the Lewis acidic additive itself and the lithium ion solvation structure in the electrolyte. According to the above table, when the type of Lewis acidic additive in the present invention is triethyl borate, the best technical effect can be obtained.

[0072] Embodiment 8

[0073] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that LiBF4 is adjusted to LiPF6, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0074] Embodiment 9

[0075] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that LiBF4 is adjusted to LiBOB, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0076] Embodiment 10

[0077] This embodiment provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Embodiment 1 is that LiBF4 is adjusted to LiTFSI, and the other components are the same as those in Embodiment 1, obtaining the electrolyte of this embodiment.

[0078] Embodiment 11

[0079] This example provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Example 1 is that LiBF4 is adjusted to LiFSI, and the other components are the same as those in Example 1, obtaining the electrolyte of this example.

[0080] Example 12

[0081] This example provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Example 1 is that LiBF4 is adjusted to LiClO4, and the other components are the same as those in Example 1, obtaining the electrolyte of this example.

[0082] The electrolytes obtained in Examples 8 to 12 were used to prepare lithium-carbon fluoride batteries, and the electrochemical performance of the batteries was tested. The results are shown in Table 4.

[0083] Table 4 Influence of different lithium salts on battery performance

[0084]

[0085] By comparing the electrochemical performance parameters of the batteries corresponding to different examples in Table 4, it can be seen that the influence of lithium salts on the performance of the prepared lithium-carbon fluoride batteries is significant. This is because the solubilities of different lithium salts in a mixed solvent of propylene carbonate and ethylene glycol dimethyl ether with a volume ratio of 1:1 are different. According to the results in the above table, when the lithium salt in the present invention is LiBF4, the effect is the best.

[0086] Comparative Example 2

[0087] This comparative example provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Example 1 is that the concentration of triethyl borate is adjusted to 0.2 mol / L, and the other components are the same as those in Example 1, obtaining the electrolyte of this example.

[0088] Comparative Example 3

[0089] This comparative example provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Example 1 is that the concentration of triethyl borate is adjusted to 0.15 mol / L, and the other components are the same as those in Example 1, obtaining the electrolyte of this example.

[0090] Comparative Example 4

[0091] This comparative example provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Example 1 is that the concentration of triethyl borate is adjusted to 0.001 mol / L, and the other components are the same as those in Example 1, obtaining the electrolyte of this example.

[0092] Comparative Example 5

[0093] This comparative example provides a high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acidic additive. The difference from Example 1 is that the concentration of triethyl borate is adjusted to 0.004 mol / L, and the other components are the same as those in Example 1, obtaining the electrolyte of this example.

[0094] The electrolytes obtained in Comparative Examples 2 to 5 were used to prepare lithium-carbon fluoride batteries, and the electrochemical performance of the batteries was tested. The results are shown in Table 5.

[0095] Table 5 Influence of the concentration of Lewis acidic additive on battery performance

[0096]

[0097] It can be seen from Table 5 that the electrolyte with the addition of a Lewis acidic additive has a higher discharge voltage plateau compared to the electrolyte without the addition. The concentration of the Lewis acidic additive has a certain influence on the discharge voltage plateau of the battery. Too low or too high a concentration will lead to capacity attenuation of the battery.

[0098] In summary, aiming at the technical problems in the prior art that the positive electrode of the lithium-carbon fluoride battery has poor conductivity, a large degree of polarization, and the generated discharge product LiF will passivate the positive electrode, affecting the energy performance of the battery at high rates. The present invention improves the discharge capacity of the battery at high rates by adding a Lewis acidic additive, changing the recrystallization path of the discharge product LiF, and adjusting the morphology of the generated LiF.

[0099] In addition, by optimizing the electrolyte composition, not only the discharge capacity of the lithium-carbon fluoride battery at high rates is improved, but also the problem of initial voltage hysteresis is solved. Moreover, because the Lewis acidic additive has a wide source and is easy to prepare, it provides the possibility for large-scale production.

[0100] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A high-rate lithium-carbon fluoride battery electrolyte containing a Lewis acid additive, characterized in that: The electrolyte is composed of a Lewis acid additive, a lithium salt and a solvent; The Lewis acidic additive includes one or more of boric acid, boric acid derivatives, aluminum salts, and arsenic-based additives; the concentration of the Lewis acidic additive relative to the electrolyte is 0.005 to 0.1 mol / L; The boric acid derivatives include boron trifluoride, triethyl borate, tri(trimethylsilyl)borate, tri(hexafluoroisopropyl)borate, triphenylborate, tri(pentafluorophenyl)borane; the aluminum salts include aluminum chloride and aluminum acetate; and the arsenic-based additive includes lithium hexafluoroarsenate.

2. The high-rate lithium-carbon fluoride battery electrolyte containing Lewis acid additives as claimed in claim 1, characterized in that: The solvent includes one or more of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, y-butyrolactone, dimethyl sulfite, ethylene glycol dimethyl ether, dimethyl sulfoxide, tetraethylene glycol dimethyl ether, tetrahydrofuran, cyclopentane sulfone, methyl phenyl sulfone, 1,3-dioxolane, and acetonitrile; the lithium salt includes one or more of LiBF4, LiPF6, LiBOB, LiTFSI, LiFSI, and LiClO4.

3. The high-rate lithium-carbon fluoride battery electrolyte containing Lewis acid additives as claimed in claim 1, characterized in that: The concentration of the lithium salt is 0.5-5 mol / L.

4. Use of the high-rate lithium-carbon fluoride battery electrolyte containing Lewis acid additives as claimed in claims 1 to 3 in the preparation of lithium-carbon fluoride batteries.

5. A method for preparing a lithium-carbon fluoride battery, characterized in that: include, In a high-purity argon environment in a glove box, a lithium sheet is used as the negative electrode, a fluorinated carbon sheet is used as the positive electrode, and a PP or PE film is used as the diaphragm; 80 to 100 μL of the electrolyte solution according to claim 1 is allowed to stand for 12 to 20 hours and then injected into a battery to assemble the battery.

6. The method for preparing a lithium-carbon fluoride battery according to claim 5, characterized in that: The method for preparing the fluorinated carbon pole piece comprises: The carbon fluoride powder, the conductive carbon and the binder are mixed in a mass ratio of 80 to 86:16 to 10:4, and uniformly dispersed in an N-methylpyrrolidone solvent to form a uniform slurry; Use a scraper to evenly coat the slurry on the current collector and control the surface density to 1-20 mg / cm 2 ; The current collector coated with the slurry is dried, and then the dried carbon fluoride pole piece is cut into carbon fluoride pole pieces with a diameter of 10 to 12 mm by a punching machine.

7. The method for preparing a lithium-carbon fluoride battery according to claim 6, characterized in that: The conductive carbon includes one or more of SuperP, acetylene black, carbon black, carbon nanotubes, graphene and Ketjen black.

8. The method for preparing a lithium-carbon fluoride battery according to claim 6, characterized in that: The binder includes one or more of polyvinylidene fluoride and sodium alginate.

9. The lithium-carbon fluoride battery prepared by the preparation method according to claims 5 to 8.

10. The lithium-carbon fluoride battery according to claim 9, characterized in that: It has the following characteristics: When the lithium-carbon fluoride battery is discharged to 1.5V at a discharge current of 2C using a blue electricity tester CT2001A, the specific capacity of the lithium-carbon fluoride battery is 690-780mA / g, and the discharge voltage is maintained at 2.65-2.8V.

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