An electrolyte and electrochemical device for a perchlorinated solvent

Abstract

An electrolyte and electrochemical device using a perchloric solvent are disclosed. The perchloric solvent electrolyte comprises an electrolyte salt and a perchloric solvent, wherein the perchloric solvent is composed of chlorinated ethers and chlorinated carbonates. The perchloric solvent electrolyte provided in this application uses chlorinated ethers and chlorinated carbonates as solvents, contains no flash point components, and exhibits low volatility, low flammability, flame retardancy, and compatibility with both positive and negative electrodes, enabling the battery to exhibit excellent electrochemical performance and high safety.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to an electrolyte and electrochemical device using a perchloric solvent. Background Technology

[0002] Currently, lithium-ion batteries are widely used in portable electronic devices, electric vehicles, and energy storage systems due to their advantages such as high energy density and long cycle life.

[0003] However, the application of lithium-ion batteries is limited by safety concerns. Under extreme conditions such as overcharging, short circuits, or mechanical damage, lithium-ion batteries may experience thermal runaway, leading to overheating, expansion, or even combustion. Furthermore, the lithium-ion graphite anode in lithium-ion batteries may react with components in the electrolyte at high temperatures, releasing a large amount of heat and further exacerbating the aforementioned thermal runaway process. In addition, the high flammability of existing electrolytes also contributes to the aforementioned thermal runaway problem. Summary of the Invention

[0004] In view of this, in order to solve at least one of the above technical problems, this application provides an electrolyte of all-chlorinated solvent.

[0005] In addition, this application also provides an electrochemical device that uses the aforementioned all-chlorinated solvent electrolyte.

[0006] This application provides an electrolyte for a perchlorinated solvent, which includes an electrolyte salt and a perchlorinated solvent, wherein the perchlorinated solvent is composed of chlorinated ethers and chlorinated carbonates.

[0007] In some possible embodiments, the chloroether is a linear chloroether.

[0008] In some possible embodiments, the chloroether has the general structural formula shown in formula (I):

[0009] (I),

[0010] R1 and R2 are independently selected from chlorine and chloroalkyl groups, respectively, and n is an integer from 1 to 10.

[0011] In some possible embodiments, the chlorinated carbonate is a cyclic chlorinated carbonate.

[0012] In some possible embodiments, the chlorinated carbonate has a general structural formula as shown in formula (II):

[0013] (II)

[0014] R3 and R4 are each independently selected from chlorine and chloroalkyl groups, and n is an integer from 1 to 10.

[0015] In some possible embodiments, the chloroether includes at least one of bis[2-(2-chloroethoxy)ethyl] ether, 1,2-bis(2-chloroethoxy)ethane, chloromethyl ether, chloroethyl ether, chloropropyl ether, and chlorobutyl ether.

[0016] In some possible embodiments, the chlorinated carbonate includes at least one of chloroethylene carbonate and dichloroethylene carbonate.

[0017] In some possible embodiments, the volume ratio of the chlorinated ether to the chlorinated carbonate in the perchlorinated solvent is 1:(0.1~1).

[0018] In some possible embodiments, the electrolyte salt is a lithium salt, including at least one of Li2SO4, LiClO4, LiNO3, LiCl, LiCF3SO3, LiPF6, Li(FSO2)2N, LiBF4, LiDFOB, Li(CF3CF2SO2)2N, and Li(CF3SO2)2N.

[0019] This application also provides an electrochemical device, which includes a positive electrode, a negative electrode, a separator, and an electrolyte of the aforementioned perchloric solvent, wherein the separator is disposed between the positive electrode and the negative electrode.

[0020] Compared to existing technologies, the perchlorinated solvent electrolyte provided in this application consists of chlorinated ethers and chlorinated carbonates. Chlorinated ethers and chlorinated carbonates have lower volatility and lower flammability than traditional organic solvents, and chlorine atoms can react with free radicals in the flame to inhibit combustion, thus playing a flame-retardant role and reducing the release of toxic gases and the risk of combustion. Therefore, the electrolyte can have the characteristics of low volatility and high flame retardancy, effectively reducing the risk of electrolyte combustion and improving the flame-retardant effect of the electrolyte on the negative electrode of the electrochemical device, thereby enhancing the safety of the electrolyte. Simultaneously, because this electrolyte has a weak solvation structure, it helps anions (such as chloride ions) form a protective interface layer on the electrode surface, and the chlorinated carbonate also helps form a stable organic layer on the electrode surface to further protect the electrode. Therefore, this electrolyte has high compatibility with both positive and negative electrodes. Furthermore, the contact interface between this electrolyte and the positive and negative electrodes has high kinetic performance, which is beneficial for rapid ion transport and reaction in the electrolyte. Electrochemical devices using this electrolyte exhibit both excellent electrochemical performance and high safety. Attached Figure Description

[0021] Figure 1 This is a graph showing the mass fraction of common battery components and the heat generated by combustion.

[0022] Figure 2The figures shown are the self-extinguishing test results of the electrolyte in Example 1 and Comparative Examples 1-2 of this application, where... Figure 2 'a' represents the self-extinguishing test result of the electrolyte in Comparative Example 1. Figure 2 b represents the self-extinguishing test result of the electrolyte in Comparative Example 2. Figure 2 c represents the self-extinguishing test result of the electrolyte in Example 1.

[0023] Figure 3 The figures shown are the flame retardant test results of the electrolyte negative electrode in Example 1 and Comparative Examples 1-2 of this application. Figure 3 'a' represents the flame retardant test result of the electrolyte negative electrode in Comparative Example 1. Figure 3 b represents the flame retardant test results of the electrolyte negative electrode in Comparative Example 2. Figure 3 c represents the flame retardant test result of the electrolyte negative electrode in Example 1.

[0024] Figure 4 The graphs show the cycle performance test results of the batteries prepared with the electrolyte in Example 1 and Comparative Example 1 of this application. Detailed Implementation

[0025] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0026] Please see Figure 1 The inventors of this application have discovered that during the combustion of lithium batteries, the heat released mainly comes from the negative electrode material and the electrolyte. The negative electrode material, especially the lithium-ion graphite negative electrode, may react with components in the electrolyte at high temperatures, releasing a large amount of heat and further exacerbating the thermal runaway process.

[0027] Therefore, this application provides an electrolyte for a perchlorinated solvent, comprising an electrolyte salt and a perchlorinated solvent, wherein the perchlorinated solvent is composed of chlorinated ethers and chlorinated carbonates. The perchlorinated solvent electrolyte provided in this application possesses both low volatility and high flame retardancy.

[0028] Chlorinated ethers can effectively improve the electrochemical performance and safety of batteries. Firstly, chlorinated ethers have good solubility, effectively dissolving electrolyte salts such as lithium salts, improving the ionic conductivity of the electrolyte, and thus enhancing battery performance. Secondly, chlorinated ethers have good stability, enhancing electrolyte stability, reducing electrolyte decomposition, and minimizing adverse reactions between the electrolyte and electrode materials, thereby improving the intrinsic safety of the electrolyte. Especially under high temperature, high voltage, or abuse conditions, the stability of chlorinated ethers helps reduce the safety hazards of battery overheating, thus improving battery safety. Furthermore, chlorinated ethers can form a protective interface layer on the electrode surface, reducing interfacial side reactions and corrosion reactions between the electrolyte and the electrode, thereby extending battery life. Through these mechanisms, chlorinated ethers not only improve battery performance but also effectively reduce the risk of thermal runaway, enhancing battery safety.

[0029] Chlorinated carbonates can form stable organic films on the positive and negative electrode surfaces of batteries. These films not only effectively isolate the electrolyte from direct contact with the electrode materials, reducing side reactions and extending battery life, but also improve the interfacial stability and kinetic properties of the positive and negative electrode materials. They reduce stress on the electrode materials caused by volume changes during charging and discharging, thereby improving the battery's cycle performance and rate performance. Chlorinated carbonates also exhibit good stability, helping to improve the battery's thermal stability, reducing the risk of thermal runaway, and enhancing battery safety under high temperature, high pressure, or abuse conditions.

[0030] Chlorinated ethers and chlorinated carbonates serve as solvents in this electrolyte, and their synergistic effect effectively improves the intrinsic safety of the electrolyte and the overall thermal stability of the battery. Furthermore, chlorine atoms can react with free radicals in a flame to inhibit combustion, thus giving the electrolyte high flame retardancy. This effectively slows down or prevents electrolyte combustion when the battery is exposed to high temperatures or other external heat sources, thereby reducing the possibility of thermal runaway, fire, or explosion. In addition, chlorinated ethers and chlorinated carbonates also improve the battery's electrochemical performance.

[0031] Chlorinated ethers can be linear, which further enhances the interaction with lithium salts, thereby increasing the solubility of lithium salts and improving the ionic conductivity of the electrolyte. Linear chlorinated ethers also exhibit lower volatility, further improving the thermal stability of the electrolyte. Furthermore, linear chlorinated ethers have lower viscosity, maintaining good flowability at low temperatures and improving the low-temperature performance of the battery.

[0032] Specifically, chloroethers have the general structural formula shown in formula (I):

[0033] (I),

[0034] R1 and R2 are each independently selected from chlorine and chloroalkyl groups, and n is an integer from 1 to 10. Further, the chloroalkyl group may include at least one of monochloromethyl, dichloromethyl, trichloromethyl, monochloroethyl, and monochlorobutyl.

[0035] In some embodiments, the chlorinated ether may include at least one selected from bis[2-(2-chloroethoxy)ethyl] ether, 1,2-bis(2-chloroethoxy)ethane, chloromethyl ether, chloroethyl ether, chloropropyl ether, and chlorobutyl ether. The chlorinated ether may further include at least one selected from [2-(2-chloroethoxy)ethyl] ether and 1,2-bis(2-chloroethoxy)ethane. These chlorinated ethers enable the electrolyte to exhibit good lithium salt solubility and interfacial stability.

[0036] Chlorinated carbonates can be cyclic chlorinated carbonates. Cyclic chlorinated carbonates facilitate further effective reaction with the electrode material surface during charge and discharge, forming a stable organic interface layer on the electrode material surface, thereby further improving the battery's interface stability and thermal stability. Simultaneously, the stable interface layer helps protect the electrode under heating conditions and reduces gas generation.

[0037] Specifically, chlorinated carbonates have the general structural formula shown in formula (II):

[0038] (II)

[0039] R3 and R4 are each independently selected from chlorine and chloroalkyl groups, and n is an integer from 1 to 10. Further, the chloroalkyl group may include at least one of monochloromethyl, dichloromethyl, trichloromethyl, monochloroethyl, and monochlorobutyl.

[0040] In some embodiments, the chlorinated carbonate may include at least one of ethylene chlorinated carbonate and ethylene dichlorocarbonate. The aforementioned chlorinated carbonate improves the interfacial film-forming properties of the battery, further enhancing its thermal stability. The chlorinated carbonate may further be ethylene chlorinated carbonate.

[0041] The electrolyte provided in this application uses a solvent consisting only of chlorinated ethers and chlorinated carbonates, making it a fully chlorinated solvent. Existing electrolytes typically contain low-flash-point components (such as ethyl methyl carbonate and dimethyl carbonate) to increase conductivity; however, these low-flash-point components can cause safety issues. The electrolyte provided in this application, using chlorinated ethers and chlorinated carbonates as solvents, can improve the electrolyte's thermal safety while maintaining conductivity, and reduces or avoids the addition of low-flash-point components, thus meeting the dual requirements for electrolyte conductivity and safety.

[0042] In a perchloric solvent electrolyte, the volume ratio of chlorinated ether to chlorinated carbonate can be 1:(0.1~1). Within this range, a good balance can be achieved between electrolyte salt solubility and interfacial film-forming performance, further improving battery electrical performance and safety. For example, the volume ratio of chlorinated ether to chlorinated carbonate can be 1:0.1, 1:0.2, 1:0.25, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, or any value within the range of any two of the above. Further, the volume ratio of chlorinated ether to chlorinated carbonate can be 1:(0.2~0.5).

[0043] The electrolyte salt can be a lithium salt, which may include at least one of the following: Li₂SO₄, LiClO₄, LiNO₃, LiCl, LiCF₃SO₃, LiPF₆, Li(FSO₂)₂N, LiBF₄, LiDFOB, Li(CF₃CF₂SO₂)₂N, and Li(CF₃SO₂)₂N. It is understood that the electrolyte salt includes, but is not limited to, the above-mentioned lithium salts, and a suitable electrolyte salt can be selected according to different application requirements.

[0044] Compared to existing technologies, the electrolyte for perchlorinated solvents provided in this application has the following advantages:

[0045] 1. Using chlorinated ethers and chlorinated carbonates as the perchloric solvent for the electrolyte: On the one hand, chlorinated ethers can efficiently dissolve electrolyte salts, improving the conductivity and intrinsic safety of the electrolyte; on the other hand, chlorinated carbonates can improve the film-forming performance of the electrolyte, forming a stable organic film on the positive and negative electrode surfaces of the battery, effectively isolating the direct contact between the electrolyte and electrode materials, and improving the battery's cycle performance, rate performance, and overall thermal stability. Through the synergistic effect of these two components, the electrolyte possesses low volatility, high flame retardancy, and excellent electrochemical performance.

[0046] 2. Further use of linear chloroethers and / or cyclic chlorocarbonates can increase the overall flash point of the electrolyte, thereby further improving battery safety.

[0047] 3. The electrolyte solvent consists only of chlorinated ethers and chlorinated carbonates, and is a perchlorinated solvent. No low flash point components are added to this perchlorinated solvent, which can further improve the safety of the electrolyte while ensuring its conductivity.

[0048] This application also provides an electrochemical device, including a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the electrolyte is the aforementioned all-chlorinated solvent electrolyte. Specifically, the separator is disposed between the positive electrode and the negative electrode.

[0049] The electrolyte uses the aforementioned perchloric solvent. Since the solvent is composed of chloroethers and chlorocarbonates, which have low volatility, low flammability, and flame retardancy, it effectively reduces the risk of electrolyte combustion and improves the flame retardant effect of the electrolyte on the negative electrode of the electrochemical device, thus enhancing the electrolyte's safety. Simultaneously, this electrolyte exhibits high compatibility with both the positive and negative electrodes and high kinetic performance at the interface with them, which is beneficial for rapid ion transport and reaction. Therefore, the electrochemical device using the aforementioned perchloric solvent electrolyte combines excellent electrochemical performance with high safety. The application of the perchloric solvent electrolyte provided in this application provides a new path to achieving highly safe batteries.

[0050] Specifically, the electrochemical device can be a lithium battery, and the positive electrode can include positive electrode materials such as lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, nickel cobalt manganese ternary positive electrode materials, and nickel cobalt aluminum ternary positive electrode materials, while the negative electrode can be a lithium graphite negative electrode.

[0051] The electrolyte and electrochemical device for the aforementioned perchloric solvent are further illustrated below through specific examples.

[0052] Example 1

[0053] This embodiment provides an electrolyte for a perchlorinated solvent, comprising an electrolyte salt, a chlorinated ether, and a chlorinated carbonate. The electrolyte salt is LiDFOB and Li(FSO₂)₂N, the chlorinated ether is bis[2-(2-chloroethoxy)ethyl] ether, and the chlorinated carbonate is ethylene chlorinated carbonate. The volume ratio of bis[2-(2-chloroethoxy)ethyl] ether to ethylene chlorinated carbonate in this electrolyte is 1:0.25, and the concentration of Li(FSO₂)₂N in the electrolyte salt is 3.5 mol·L⁻¹. -1 The concentration of LiDFOB is 2 wt% of the total mass of the electrolyte, which is a chlorinated solvent electrolyte (ACSE1).

[0054] The specific preparation method includes the following steps, which can be carried out in an argon-filled glove box:

[0055] Step S1: Weigh 0.0035 mol of Li(FSO2)2N salt.

[0056] Step S2: Dissolve Li(FSO2)2N salt in a mixed solution of 0.8 mL bis[2-(2-chloroethoxy)ethyl] ether and 0.2 mL chloroethylene carbonate.

[0057] In step S3, add 2 wt% LiDFOB salt of electrolyte and mix well to obtain ACSE1.

[0058] Example 2

[0059] This embodiment provides an electrolyte for a perchlorinated solvent, comprising an electrolyte salt, a chlorinated ether, and a chlorinated carbonate. The electrolyte salts are LiDFOB and Li(FSO₂)₂N, the chlorinated ether is bis[2-(2-chloroethoxy)ethyl] ether, and the chlorinated carbonate is ethylene chlorinated carbonate. The volume ratio of bis[2-(2-chloroethoxy)ethyl] ether to ethylene chlorinated carbonate in this electrolyte is 1:0.5, and the electrolyte salt concentration is approximately 3.5 mol·L⁻¹ for Li(FSO₂)₂N. -1 LiDFOB is 2 wt% of the total electrolyte mass, and the electrolyte is a chlorinated solvent electrolyte (ACSE2).

[0060] The specific preparation method includes the following steps, which can be carried out in an argon-filled glove box:

[0061] Step S1: Weigh 0.0035 mol of Li(FSO2)2N salt.

[0062] Step S2: Dissolve Li(FSO2)2N salt in a mixed solution of 0.67 mL bis[2-(2-chloroethoxy)ethyl] ether and 0.33 mL chloroethylene carbonate.

[0063] In step S3, add 2 wt% LiDFOB salt of electrolyte and mix well to obtain ACSE2.

[0064] Example 3

[0065] This embodiment provides an electrolyte for a perchlorinated solvent, comprising an electrolyte salt, a chloroether, and a chlorocarbonate. The electrolyte salt is LiDFOB and Li(FSO₂)₂N, the chloroether is 1,2-bis(2-chloroethoxy)ethane, and the chlorocarbonate is ethylene chlorocarbonate. The volume ratio of 1,2-bis(2-chloroethoxy)ethane to ethylene chlorocarbonate in this electrolyte is 1:0.25, and the electrolyte salt concentration is approximately 3.5 mol·L⁻¹ for Li(FSO₂)₂N. -1 LiDFOB is 2 wt% of the total electrolyte mass, and the electrolyte is a chlorinated solvent electrolyte (ACSE3).

[0066] The specific preparation method includes the following steps, which can be carried out in an argon-filled glove box:

[0067] Step S1: Weigh 0.0035 mol of Li(FSO2)2N salt.

[0068] Step S2: Dissolve Li(FSO2)2N salt in a mixed solution of 0.8 ml 1,2-bis(2-chloroethoxy)ethane and 0.2 ml chloroethylene carbonate.

[0069] In step S3, add 2 wt% LiDFOB salt of electrolyte and mix well to obtain ACSE3.

[0070] Comparative Example 1

[0071] This comparative example provides a carbonate-based electrolyte comprising an electrolyte salt and a carbonate-based solvent. The electrolyte salt is LiPF6, and the carbonate-based solvent is ethylene carbonate and dimethyl carbonate. The volume ratio of ethylene carbonate to dimethyl carbonate in this carbonate-based electrolyte is 1:1, and the electrolyte salt concentration is approximately 1 mol·L⁻¹. -1 .

[0072] The specific preparation method includes the following steps, which can be carried out in an argon-filled glove box:

[0073] Step S1: Weigh 0.001 mol of LiPF6 salt.

[0074] In step S2, the LiPF6 salt is dissolved in 0.5 mL of ethylene carbonate and 0.5 mL of dimethyl carbonate, and mixed evenly to obtain the electrolyte.

[0075] Comparative Example 2

[0076] This comparative example provides an ether-based electrolyte comprising an electrolyte salt and an ether solvent. The electrolyte salt is Li(FSO₂)₂N, i.e., LiFSI, and the ether solvent is ethylene glycol dimethyl ether and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (HFE). The volume ratio of ethylene glycol dimethyl ether to HFE in this ether electrolyte is 1:1, and the electrolyte salt concentration is approximately 1 mol·L⁻¹. -1 .

[0077] The specific preparation method includes the following steps, which can be carried out in an argon-filled glove box:

[0078] Step S1: Weigh 0.001 mol of Li(FSO2)2N salt.

[0079] In step S2, Li(FSO2)2N salt is dissolved in 0.5 mL of ethylene glycol dimethyl ether and 0.5 mL of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and mixed evenly to obtain an electrolyte.

[0080] 1. The electrolytes obtained in Example 1 and Comparative Examples 1-2 were subjected to the following tests:

[0081] (a) Self-extinguishing test: Electrolytes of the same mass prepared in Example 1 and Comparative Examples 1-2 were placed in the positive electrode shell and ignited using an igniter. The self-extinguishing time of the electrolyte was tested. The self-extinguishing time refers to the time it takes for the electrolyte or battery to extinguish itself after being exposed to external heat sources such as ignition or high temperature. It reflects the safety of the electrolyte. The test results are shown in [reference missing]. Figure 2 .

[0082] (II) Negative Electrode Flame Retardant Test: A certain amount of the electrolyte prepared in Example 1 and Comparative Examples 1-2 was placed in the positive electrode shell along with the lithium graphite negative electrode sheet. An ignition experiment was conducted using an igniter, and the self-extinguishing time was tested. The test results are shown in [reference missing]. Figure 3 .

[0083] (III) The electrical performance test conditions are as follows: The electrolytes prepared in Example 1 and Comparative Example 1 are used as electrolytes, and the amount of electrolyte added is 40~100μL; lithium iron phosphate is used as the positive electrode material and graphite is used as the negative electrode material to prepare a graphite||lithium iron phosphate full cell.

[0084] The battery prepared above was subjected to cycle performance testing under the following conditions: 25℃, voltage range of 2.4V~4.2V, and charge / discharge rate of 0.5C. The battery charge / discharge specific capacity and coulombic efficiency were measured, and the results are as follows: Figure 4 As shown.

[0085] The above results show that:

[0086] like Figure 2 As shown, compared to the conventional carbonate-based electrolytes and ether solvents in Comparative Examples 1-2, the perchloric solvent electrolyte in Example 1 is more difficult to ignite, with a self-extinguishing time of 0 s·g. -1 The self-extinguishing time of Comparative Example 1 is 50 s·g. -1 The self-extinguishing time of Comparative Example 2 is 62 s·g. -1 This indicates that the electrolyte with all-chlorinated solvent in Example 1 has higher flame retardancy, which helps to reduce safety hazards when the battery overheats.

[0087] like Figure 3 As shown, when lithium-ion graphite anodes were added together for ignition experiments, compared to Comparative Examples 1-2, the electrolyte of the perchloric solvent in Example 1 was difficult to ignite, with a self-extinguishing time of 0 s·g. -1 The self-extinguishing time of Comparative Example 1 is 65 s·g. -1 The self-extinguishing time of Comparative Example 2 is 86 s·g. -1 This indicates that the electrolyte of the perchloric solvent in Example 1 has high flame retardancy and can also play an effective flame retardant role when ignited together with the negative electrode.

[0088] like Figure 4As shown, in the cycle test, the batteries prepared using the electrolytes of Example 1 and Comparative Example 1 showed that the specific capacity and coulombic efficiency of Example 1 were better than those of Comparative Example 1, and the battery of Example 1 could be stably cycled for more than 1000 cycles, which indicates that the electrolyte with all-chlorine solvent has better cycle stability.

[0089] Therefore, the electrolytes of the perchlorinated solvent provided in Examples 1-3 of this application are composed of chlorinated ethers and chlorinated carbonates, and have the characteristics of low volatility and high flame retardancy. The electrolytes not only have good safety, but also have good electrochemical performance, which can ensure the safety and stable cycling of the battery.

[0090] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An electrolyte for electrolysis of a perchlorinated solvent, characterized in that, The electrolyte is composed of an electrolyte salt and a perchloro solvent, wherein the perchloro solvent is composed of a chlorinated ether and a chlorinated carbonate, and the volume ratio of the chlorinated ether to the chlorinated carbonate in the perchloro solvent is 1: (0.1-1).

2. The electrolyte of the perchloro solvent according to claim 1, characterized in that, The chlorinated ether is a linear chlorinated ether.

3. The electrolyte of the perchloro solvent according to claim 2, characterized in that, The chlorinated ether has a general structural formula as shown in formula (I): （Ⅰ）， wherein R1 and R2 are independently selected from one of chlorine and chlorinated alkyl, and n is an integer of 1-10.

4. The electrolyte of the perchloro solvent according to claim 1, characterized in that, The chlorinated carbonate is a cyclic chlorinated carbonate.

5. The electrolyte of the perchloro solvent according to claim 4, characterized in that, The chlorinated carbonate has a general structural formula as shown in formula (II): （Ⅱ）， wherein R3 and R4 are independently selected from one of chlorine and chlorinated alkyl, and n is an integer of 1-10.

6. The electrolyte of the perchloro solvent according to claim 1, characterized in that, The chlorinated ether includes at least one of bis[2-(2-chloroethoxy)ethyl]ether, 1,2-bis(2-chloroethoxy)ethane, chloromethyl ether, chloroethyl ether, chloropropyl ether and chlorobutyl ether.

7. The electrolyte of the perchloro solvent according to claim 1, characterized in that, The chlorinated carbonate includes at least one of chloroethylene carbonate and dichloroethylene carbonate.

8. The electrolyte of the perchloro solvent according to claim 1, characterized in that, The electrolyte salt is a lithium salt, and the lithium salt includes at least one of Li2SO4, LiClO4, LiNO3, LiCl, LiCF3SO3, LiPF6, Li(FSO2)2N, LiBF4, LiDFOB, Li(CF3CF2SO2)2N and Li(CF3SO2)2N.

9. An electrochemical device, characterized by, The battery includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte, the separator is arranged between the positive electrode sheet and the negative electrode sheet, and the electrolyte is the electrolyte of the perchloro solvent according to any one of claims 1-8.

Images