A two-phase electrolyte and electrochemical device

Abstract

A two-phase electrolyte and electrochemical device are disclosed. The two-phase electrolyte comprises an electrolyte salt, water, and an organic solvent, wherein the difference in Hildebrand solubility parameters between water and the organic solvent is 13.5 to 15.3, and the relative permittivity of the organic solvent is 5 to 80. In the two-phase electrolyte provided by this application, the aqueous and organic phases can achieve spontaneous phase separation. This two-phase electrolyte is a stable aqueous-organic phase two-phase electrolyte, which can improve problems such as hydrogen evolution corrosion and dendrite growth at the negative electrode, and improve ion transport efficiency. Batteries using this two-phase electrolyte exhibit better long-term cycle life and high capacity retention.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a two-phase electrolyte and an electrochemical device. Background Technology

[0002] Because non-aqueous electrolytes are detrimental to the activation of the transition metal oxide lattice on the positive electrode side of zinc-ion batteries, they slow down ion transport kinetics, leading to increased battery polarization and low coulombic efficiency. In recent years, aqueous zinc-ion batteries have received widespread attention and show great promise due to their safety and environmental friendliness. The use of aqueous electrolytes can improve ion transport at the transition metal oxide positive electrode, thereby enhancing the electrical performance of aqueous zinc-ion batteries.

[0003] However, aqueous electrolytes are incompatible with zinc metal anodes, which can easily induce severe hydrogen evolution reactions and dendrite growth, leading to energy loss and reduced efficiency of the battery. Summary of the Invention

[0004] In view of this, in order to solve at least one of the above technical problems, this application provides a self-splitting two-phase electrolyte.

[0005] In addition, this application also provides an electrochemical device that uses the aforementioned biphase electrolyte.

[0006] This application provides a biphase electrolyte comprising an electrolyte salt, water, and an organic solvent, wherein the difference between the Hildebrand solubility parameters of the water and the organic solvent is 13.5 to 15.3, and the relative permittivity of the organic solvent is 5 to 80.

[0007] In some possible embodiments, the organic solvent is a hydrophobic aprotic halide solvent.

[0008] In some possible embodiments, the organic solvent includes at least one of fluoroethylene carbonate, N,N-dimethyltrifluoroacetamide, methyltrifluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, chloromethylethyl carbonate, and bis(2-chloroethyl) carbonate.

[0009] In some possible embodiments, the volume ratio of water to organic solvent in the electrolyte is 1:(1~4).

[0010] In some possible embodiments, the electrolyte salt includes hydrophilic zinc salts and amphiphilic zinc salts.

[0011] In some possible embodiments, the hydrophilic zinc salt includes at least one of zinc sulfate, zinc chloride, zinc nitrate, and zinc acetate; and / or

[0012] The hydrophilic zinc salt has a molar concentration of 0.5 mol·L⁻¹ in the electrolyte. -1 ~3mol·L -1 .

[0013] In some possible embodiments, the amphiphilic zinc salt includes at least one of zinc tetrafluoroborate, zinc trifluoromethanesulfonate, and zinc bis(trifluoromethanesulfonyl)imide; and / or

[0014] The amphiphilic zinc salt has a molar concentration of 0.5 mol·L⁻¹ in the electrolyte. -1 ~4mol·L -1 .

[0015] In some possible embodiments, the electrolyte further includes a salting-out agent.

[0016] In some possible embodiments, the salting-out agent includes at least one of aluminum sulfate, magnesium sulfate, and ammonium sulfate; and / or

[0017] The molar concentration of the salting-out agent in the electrolyte is 0.1 mol·L⁻¹. -1 ~4mol·L -1 .

[0018] This application also provides an electrochemical device, which includes a positive electrode, a negative electrode, a separator, and the aforementioned electrolyte, wherein the separator is disposed between the positive electrode and the negative electrode.

[0019] Compared to existing technologies, the biphase electrolyte provided in this application uses both water and an organic solvent as solvents for the electrolyte salt. By limiting the difference in Hildebrand solubility parameters between water and the organic solvent to 13.5–15.3, and the relative permittivity of the organic solvent to 5–80, spontaneous separation of the aqueous and organic phases is achieved within the electrolyte, utilizing the dielectric properties of the organic solvent and its compatibility with water. This results in the construction of a stable, stratified aqueous-organic biphase electrolyte. In this electrolyte, the organic phase effectively suppresses hydrogen evolution corrosion and dendrite growth by optimizing zinc deposition behavior on the negative electrode side and forming a stable solid electrolyte interface. Simultaneously, the aqueous phase promotes ion transport kinetics on the positive electrode side, facilitating rapid ion transport and reactions within the electrolyte. Electrochemical devices using this electrolyte exhibit long cycle life and high capacity retention. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an electrochemical device provided in an embodiment of this application.

[0021] Figure 2 The image shows the cycle life test results of the Zn / / Zn symmetric cells assembled using the electrolytes in Example 1 and Comparative Example 1 of this application.

[0022] Figure 3 The coulombic efficiency test results are shown for the Zn / / Cu asymmetric cells assembled using the electrolytes in Example 1 and Comparative Example 1 of this application.

[0023] Figure 4 The graph shows the cycle performance test results of the Zn / / V2O5 full cells assembled using the electrolytes in Example 1 and Comparative Example 1 of this application.

[0024] Figure 5 The above are in-situ electrochemical mass spectra of Zn / / V2O5 pouch cells assembled using the electrolytes in Example 1 and Comparative Example 1 of this application.

[0025] Figure 6 This is a deformation test diagram of a Zn / / V2O5 pouch cell assembled using the electrolyte in Example 1 of this application.

[0026] Figure 7 The deformation test diagram shows the Zn / / V2O5 pouch cell assembled using the electrolyte in Comparative Example 1 of this application. Detailed Implementation

[0027] 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.

[0028] The inventors of this application have discovered that in zinc-ion batteries, a single aqueous electrolyte can lead to severe corrosion and hydrogen evolution on the zinc anode side, while a single organic electrolyte can cause slow ion transport kinetics, resulting in increased battery polarization and low coulombic efficiency. Furthermore, the design of traditional two-phase electrolytes can easily lead to battery failure due to the metastable nature of the system causing migration of the two-phase interface.

[0029] Therefore, this application provides a self-separating biphase electrolyte comprising: an electrolyte salt, water, and an organic solvent, wherein the difference between the Hildebrand solubility parameters of the water and the organic solvent is 13.5 to 15.3, and the relative permittivity of the organic solvent is 5 to 80.

[0030] The difference between the Hildebrand solubility parameters of the organic solvent and water is 13.5 to 15.3. This difference indicates a weak affinity and poor compatibility between the organic solvent and water, which promotes spontaneous phase separation in the electrolyte and facilitates the formation of a stable aqueous-organic biphase electrolyte. If the difference is too low (below 13.5), the organic solvent and water may become miscible, forming a homogeneous solution with insufficient phase separation. If the difference is too high (above 15.3), the interfacial tension between water and the organic solvent may be too large. The difference between the Hildebrand solubility parameters of the organic solvent and water can further be 13.5 to 15.3, and exemplaryly, it can be any value within the range of 13.5, 14, 14.5, 15, 15.3, or any two of the above values.

[0031] The relative permittivity of the aforementioned organic solvents is in the range of 5 to 80, enabling the solvent to effectively dissolve the electrolyte salt and provide good ionic conductivity. This range of relative permittivity maintains the stable dissolution of the electrolyte salt in the organic solvent and promotes efficient ion transfer between the aqueous and organic phases. Combined with the difference in Hildebrand solubility parameters between the organic solvent and water, the dissolution of the electrolyte salt further reduces the affinity between water and the organic solvent, thereby further promoting stratification and making it easier for the electrolyte to form a stable biphase structure. If the relative permittivity of the organic solvent is too low (below 5), it will affect the solubility of the salt in the organic solvent; if the relative permittivity of the organic solvent is too high (above 80), it may cause excessively strong interactions between zinc ions and the solvent, which is detrimental to the subsequent desolvation process and leads to slower kinetics. The relative permittivity of the organic solvent can further be in the range of 5 to 80, and exemplaryly, it can be any value within the range of 5, 10, 20, 30, 40, 50, 60, 70, 80, or any two of the above values.

[0032] By introducing the aforementioned organic solvent into the aqueous electrolyte, and utilizing the suitable dielectric properties of the organic solvent and its difference in compatibility with water, spontaneous separation of the aqueous and organic phases can be achieved within the electrolyte, thus realizing the construction of a stable, stratified aqueous-organic two-phase electrolyte. In this two-phase electrolyte, the organic phase effectively suppresses problems such as hydrogen evolution corrosion and dendrite growth by uniformly depositing zinc on the negative electrode side and forming a stable solid electrolyte interface, thereby reducing gas production and capacity decay. Simultaneously, the aqueous phase promotes ion transport kinetics on the positive electrode side, which is beneficial for rapid ion transport and reaction in the electrolyte, thereby increasing the reaction rate.

[0033] In some embodiments, the organic solvent can be a hydrophobic aprotic halogenated solvent. In addition to having a large difference in Hildebrand solubility parameter from water, such organic solvents are also aprotic and do not participate in proton migration or reaction, which can further effectively suppress hydrogen evolution reaction and reduce gas generation.

[0034] In some embodiments, the organic solvent may include at least one of fluoroethylene carbonate, N,N-dimethyltrifluoroacetamide, methyltrifluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, chloromethylethyl carbonate, and bis(2-chloroethyl) carbonate. It is understood that hydrophobic aprotic halogenated solvents include, but are not limited to, the solvents described above.

[0035] In some embodiments, the volume ratio of water to organic solvent in the biphase electrolyte can be 1:(1~4), further can be 1:(1~2), and exemplary can be any value within the range of any two of the above values, such as 1:1, 1:2, 1:3, 1:4.

[0036] In some embodiments, the electrolyte salt may include a hydrophilic zinc salt and an amphiphilic zinc salt. The hydrophilic zinc salt is highly soluble in the aqueous phase, providing abundant zinc ions to the electrolyte and improving the conductivity of the biphase electrolyte. The amphiphilic zinc salt, due to the different partition coefficients in the aqueous and organic phases, allows some water to be "captured" in the organic phase, resulting in a small amount of water in the organic phase. The presence of this small amount of water in the organic phase helps provide a good ion transport channel, further improving the conductivity of the biphase electrolyte.

[0037] In some embodiments, the hydrophilic zinc salt may include at least one of zinc sulfate, zinc chloride, zinc nitrate, and zinc acetate. All of the above-mentioned hydrophilic zinc salts have good water solubility and can effectively provide zinc ions for the two-phase electrolyte.

[0038] In some embodiments, the molar concentration of the hydrophilic zinc salt in the biphase electrolyte can be 0.5 mol·L⁻¹. -1 ~3mol·L -1 Furthermore, it can be 0.5 mol·L -1 ~1.5mol·L -1 For example, it can be 1 mol·L -1 2 mol·L -1 3 mol·L -1 Or any value within the range of any two of the above values.

[0039] In some embodiments, the amphiphilic zinc salt may include at least one of zinc tetrafluoroborate, zinc trifluoromethanesulfonate, and zinc bis(trifluoromethanesulfonyl)imide.

[0040] In some embodiments, the molar concentration of the amphiphilic zinc salt in the biphase electrolyte can be 0.5 mol·L⁻¹. -1 ~4mol·L -1 Furthermore, it can be 1 mol·L -1 ~3mol·L -1 For example, it can be 3 mol·L -1 1 mol·L -1 2 mol·L -1 3 mol·L -1 4 mol·L -1 Or any value within the range of any two of the above values.

[0041] In some embodiments, the biphase electrolyte may also include a salting-out agent. By adding a salting-out agent to the biphase electrolyte, the water content in the organic phase can be adjusted to maintain the water content in the organic phase within a reasonable range, enabling the zinc symmetric battery to achieve stable cycling, further promoting the formation of the solid electrolyte interface, optimizing zinc ion deposition / stripping efficiency, and inhibiting hydrogen evolution corrosion and dendrite growth.

[0042] In some embodiments, the salting-out agent may include at least one of aluminum sulfate, magnesium sulfate, and ammonium sulfate.

[0043] In some embodiments, the molar concentration of the salting-out agent in the two-phase electrolyte can be 0.1 mol·L⁻¹. -1 ~4mol·L -1 Furthermore, it can be 0.1 mol L. -1 ~1 mol L -1 For example, it can be 0.1 mol·L -1 0.2 mol·L -1 0.5 mol·L -1 1 mol·L -1 2 mol·L -1 3 mol·L -1 4 mol·L -1 Or any value within the range of any two of the above values.

[0044] Compared with the prior art, the biphase electrolyte provided in this application has the following beneficial effects:

[0045] 1. An electrolyte is prepared using an organic solvent with a Hildebrand solubility parameter difference of 13.5~15.3 with water and a relative permittivity of 5~80. This can form a stable aqueous-organic biphase electrolyte, which can effectively suppress problems such as hydrogen evolution corrosion and dendrite growth during charging and discharging, improve ion transport rate, and enhance electrolyte conductivity.

[0046] 2. Using amphiphilic zinc salt as a partial electrolyte salt allows the organic phase to contain a small amount of water, which helps to provide a good ion transport channel and further improves the conductivity of the biphase electrolyte.

[0047] 3. By adding a salting-out agent, the water content of the organic phase can be precisely controlled, further reducing side reactions such as corrosion of the negative electrode, hydrogen evolution, and dendrite growth.

[0048] Please see Figure 1 This application also provides an electrochemical device 100, including a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte 40, wherein the electrolyte 40 is the aforementioned biphase electrolyte. Specifically, the separator 30 is disposed between the positive electrode 10 and the negative electrode 20. Specifically, the electrochemical device 100 can be an aqueous zinc metal battery, the positive electrode 10 can include a transition metal oxide positive electrode material, such as vanadium pentoxide positive electrode material, and the negative electrode 20 can be a zinc metal negative electrode.

[0049] Electrolyte 40 uses the aforementioned two-phase electrolyte. Since the difference in Hildebrand solubility parameters between the organic solvent and water in the two-phase electrolyte is 13.5–15.3, and the relative permittivity of the organic solvent is 5–80, the electrolyte spontaneously achieves phase separation, resulting in a two-phase electrolyte with stable layering characteristics consisting of an aqueous phase and an organic phase. In the electrochemical device 100, the organic phase on the negative electrode 20 side optimizes zinc deposition behavior and forms a stable solid electrolyte interface, effectively suppressing problems such as hydrogen evolution corrosion and dendrite growth. This reduces capacity decay and efficiency loss in the electrochemical device 100 caused by negative electrode damage, and also reduces gas generation, improving the safety of the electrochemical device 100. The aqueous phase on the positive electrode 10 side promotes ion transport kinetics, accelerates rapid ion transport and reaction in the two-phase electrolyte, and improves the charge-discharge capability of the electrochemical device 100. Therefore, the electrochemical device 100 using the aforementioned two-phase electrolyte has a long cycle life and high capacity retention. The application of the biphase electrolyte in batteries provided in this application provides a new path for achieving long-life aqueous zinc-ion batteries.

[0050] The aforementioned two-phase electrolyte and electrochemical device will be further illustrated below through specific embodiments.

[0051] Example 1

[0052] The electrolyte comprises an electrolyte salt (a hydrophilic zinc salt and an amphiphilic zinc salt), a salting-out agent, an organic solvent, and water. The hydrophilic zinc salt is zinc sulfate, the amphiphilic zinc salt is zinc trifluoromethanesulfonate, the salting-out agent is magnesium sulfate, and the organic solvent is methyltrifluoroethyl carbonate. The concentration of the hydrophilic zinc salt in the electrolyte is 1 mol·L⁻¹. -1The concentration of the amphiphilic zinc salt is 1 mol·L⁻¹ -1 The salting-out agent concentration is 0.5 mol·L⁻¹ -1 .

[0053] The specific preparation method includes the following steps:

[0054] Step S1: Add 287.56g of hydrophilic zinc sulfate and 60.18g of magnesium sulfate salting agent to water, mix well, and then dilute with water to 1L to obtain an aqueous electrolyte.

[0055] Step S2: Add 363.53g of amphiphilic zinc salt zinc trifluoromethanesulfonate to the organic solvent, mix well, and then dilute to 1L with the organic solvent to obtain the organic electrolyte.

[0056] Step S3: Take the same volume of the above-mentioned aqueous electrolyte and organic electrolyte and place them in a container. After stirring thoroughly, the electrolyte will separate into a stable aqueous phase and an organic phase. This electrolyte is a biphase electrolyte with a stable interfacial phase.

[0057] Example 2

[0058] The difference between Example 2 and Example 1 is that the hydrophilic zinc salt used in step S1 is zinc chloride, and the preparation method of the rest of the electrolyte is the same as that in Example 1, which will not be described in detail here.

[0059] Example 3

[0060] The difference between Example 3 and Example 1 is that the amphiphilic zinc salt used in step S2 is zinc bis(trifluoromethanesulfonyl)imide, and the preparation method of the rest of the electrolyte is the same as that in Example 1, which will not be described in detail here.

[0061] Comparative Example 1

[0062] Add 363.53g of zinc trifluoromethanesulfonate to water, mix well, and then dilute to 1L with water to obtain an aqueous electrolyte.

[0063] 1. The electrolytes obtained in Example 1 and Comparative Example 1 were subjected to the following tests:

[0064] (a) The electrolytes prepared in Example 1 and Comparative Example 1 were applied to Zn / / Zn symmetric cells: The cycle performance of the Zn / / Zn symmetric cells was simulated using a CR2032 coin cell system, with effective areas of 1.13 cm² for both positive and negative electrodes. 2 Take 100 μL of the organic phase in the biphase electrolyte of Comparative Example 1 or Example 1 to wet the glass fiber membrane (membrane thickness is 675 μm). When assembling the battery, stack the zinc foil, glass fiber membrane and zinc foil in the following order from top to bottom.

[0065] The cycle life of the Zn / / Zn symmetric cell prepared above was determined by constant current charge-discharge testing. The test conditions were as follows: current was 1 mA·cm⁻¹. -2 The capacity is 1mAh·cm -2 That is, one cycle takes 2 hours, and the test results are as follows: Figure 2 As shown.

[0066] (II) The electrolytes prepared in Example 1 and Comparative Example 1 were applied to Zn / / Cu asymmetric batteries: The cycle performance of the Zn / / Cu asymmetric batteries was simulated using a CR2032 coin cell system, with effective areas of 1.13 cm² for both positive and negative electrodes. 2 Take 100 μL of the organic phase in the biphase electrolyte of Comparative Example 1 or Example 1 to wet the glass fiber membrane (membrane thickness is 675 μm). When assembling the battery, stack the zinc foil, glass fiber membrane and copper foil in the order from top to bottom.

[0067] The coulombic efficiency of the Zn / / Cu asymmetric cell prepared above was determined by constant current charge-discharge testing. The test conditions were as follows: discharge current was 0.5 mA·cm⁻¹. -2 The charging cutoff voltage is 0.5V, and the test results are as follows: Figure 3 As shown.

[0068] (III) The electrolytes prepared in Example 1 and Comparative Example 1 were applied to Zn / / V2O5 full cells: The cycle performance of the Zn / / V2O5 full cells was simulated using a CR2032 coin cell system, where the negative electrode was zinc foil and the positive electrode was V2O5, with an effective area of ​​1.13 cm² for both electrodes. 2 In Comparative Example 1, 100 μL of zinc trifluoromethanesulfonate electrolyte was dropped onto a glass fiber membrane (675 μm thick). In Example 1, 50 μL of the aqueous phase from the biphase electrolyte was dropped onto a glass fiber membrane (260 μm thick), and 50 μL of the organic phase from the biphase electrolyte of Example 1 was dropped onto a polypropylene separator (20 μm thick). The positive electrode was prepared by mixing active material, acetylene black, and PVDF in a mass ratio of 7:2:1 to form a slurry, which was then coated onto titanium foil and dried in a forced-air drying oven at 80°C for 6–12 hours. During battery assembly, the zinc foil, polypropylene separator, glass fiber membrane, and positive electrode were stacked sequentially from top to bottom.

[0069] The Zn / / V2O5 full cell prepared above was subjected to constant current (2A·g) -1 The battery's cycle performance was tested by charge and discharge, with a charge / discharge voltage range of 0.5V to 1.5V. The test results are as follows: Figure 4 As shown.

[0070] (iv) The electrolytes prepared in Example 1 and Comparative Example 1 were applied to Zn / / V2O5 pouch cells: The cycle performance of the Zn / / V2O5 pouch cells was simulated using an aluminum-plastic film pouch cell system, in which the negative electrode was zinc foil with an effective area of ​​16 cm². 2 The positive electrode is V₂O₅, with an effective area of ​​12.25 cm². 2 Comparative Example 1 used the prepared aqueous electrolyte, and the separator was a glass fiber membrane (thickness 675 μm). In Example 1, the aqueous phase of 250 μL of the biphase electrolyte was dropped onto a glass fiber membrane (thickness 260 μm), and the organic phase of 250 μL of the biphase electrolyte was dropped onto a polypropylene separator (thickness 20 μm). The positive electrode was prepared by mixing active material, acetylene black, and PVDF in a mass ratio of 7:2:1 to form a slurry, which was then coated onto titanium foil and dried in a forced-air drying oven at 80°C for 6-12 hours. When assembling the battery, the zinc foil, polypropylene separator, glass fiber membrane, and positive electrode sheet were stacked sequentially from top to bottom.

[0071] The Zn / / V₂O₅ pouch cell prepared above was subjected to a constant current (0.5 A·g) -1 Charge-discharge tests were conducted, with a charge-discharge voltage range of 0.5V to 1.5V. In-situ electrochemical mass spectrometry was performed on the cycled pouch cells, and the results are as follows: Figure 5 As shown; the deformation of the pouch cell after cycling in Example 1 was measured, and the results are as follows. Figure 6 As shown; the deformation of the pouch cell after cycling in Comparative Example 1 was measured, and the results are as follows. Figure 7 As shown.

[0072] The results show that the Zn / / Zn symmetric battery assembled using the electrolyte in Comparative Example 1 has a cycle life of 90 hours, after which a short circuit occurs; the coulombic efficiency of the Zn / / Cu asymmetric battery is less than 85%; and the capacity of the Zn / / V₂O₅ full cell continuously decreases during cycling. Compared to Comparative Example 1, the Zn / / Zn symmetric battery assembled using the electrolyte in Example 1 has a cycle life of 1200 hours, the Zn / / Cu asymmetric battery can be stably cycled for 950 cycles with an average coulombic efficiency greater than 99%, and the capacity of the Zn / / V₂O₅ full cell can be stably cycled for more than 3000 cycles. The battery assembled with the two-phase electrolyte in Example 1, because the two-phase electrolyte simultaneously improves the side reactions on the negative electrode side and the ion transport rate on the positive electrode side, has a better cycle life, coulombic efficiency, and capacity than the battery assembled with the aqueous electrolyte in Comparative Example 1.

[0073] Furthermore, the Zn / / V2O5 pouch cell assembled using the electrolyte of Comparative Example 1 produced a large amount of hydrogen gas after cycling, and the Zn / / V2O5 pouch cell underwent significant deformation. Compared to Comparative Example 1, the Zn / / V2O5 pouch cell assembled using the biphase electrolyte of Example 1 showed significantly reduced gas production, and the Zn / / V2O5 pouch cell did not exhibit significant deformation. This is because the biphase electrolyte is a stable aqueous-organic phase biphase electrolyte, reducing side reactions such as hydrogen evolution corrosion and dendrite growth at the negative electrode. The battery using this biphase electrolyte exhibited better long-term cycle life and high capacity retention.

[0074] 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. A two-phase electrolyte, characterized in that, The electrolyte salt, water and an organic solvent, wherein the difference between the Hildebrand solubility parameters of water and the organic solvent is 13.5-15.3, and the relative dielectric constant of the organic solvent is 5-80, and the organic solvent is a hydrophobic aprotic halogenated solvent. The organic solvent includes at least one of fluoroethylene carbonate, N,N-dimethyl trifluoroacetamide, methyl trifluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, chloromethyl ethyl carbonate and bis(2-chloroethyl) carbonate.

2. The dual-phase electrolyte of claim 1, wherein, In the dual-phase electrolyte, the volume ratio of the water to the organic solvent is 1:(1-4).

3. The dual-phase electrolyte of claim 1, wherein, The electrolyte salt includes a hydrophilic zinc salt and a biphasic zinc salt.

4. The dual-phase electrolyte of claim 1, wherein, The hydrophilic zinc salt includes at least one of zinc sulfate, zinc chloride, zinc nitrate and zinc acetate; and / or 5. The dual-phase electrolyte of claim 4, wherein, The biphasic zinc salt includes at least one of zinc tetrafluoroborate, zinc triflate and zinc bistrifluoromethanesulfonimide; and / or The molar concentration of the hydrophilic zinc salt in the two-phase electrolyte is 0.5 mol L -1 3 mol L -1 .

6. The dual-phase electrolyte of claim 4, wherein, The dual-phase electrolyte further includes a salting-out agent. The molar concentration of the amphiphilic zinc salt in the two-phase electrolyte is 0.5 mol L -1 4 mol L -1 .

7. The dual-phase electrolyte of claim 1, wherein, The salting-out agent includes at least one of aluminum sulfate, magnesium sulfate and ammonium sulfate; and / or 8. The dual-phase electrolyte of claim 7, wherein, The battery includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte, the separator being arranged between the positive electrode sheet and the negative electrode sheet; wherein the electrolyte is the dual-phase electrolyte according to any one of claims 1-8. The molar concentration of the salting agent in the two-phase electrolyte is 0.1 mol·L -1 4 mol·L -1 .

9. An electrochemical device, characterized by, ​

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