Electrolyte and preparation process thereof

Abstract

The invention relates to the field of electrolyte, in particular to electrolyte and a preparation process thereof. The technology comprises the following steps that firstly, materials are added into the space between a barrel I and a barrel II through a material adding hole I; 2, pushing the materials to mix and react through the rotation of a plurality of blade plates; 3, performing heat exchange with the materials from the inner sides and the outer sides of the barrel I and the barrel II through an outer heating barrel I, an outer heating barrel II and an inner heating barrel to adjust the temperature of the materials so as to prepare the electrolyte; and step 4, driving an annular plate II to rotate to enable a discharge hole I, a discharge hole II, a filter plate and a discharge hole III to coincide, and carrying out rough filtration to collect the electrolyte while blanking the electrolyte. According to the electrolyte preparation device, materials can be loaded, dispersion, mixing and temperature control are facilitated, the mixed materials are pushed to reciprocate to be stirred and impacted, the temperature of the materials is adjusted from the interior and the exterior of the annular tubular container, and the electrolyte preparation speed is increased.

Description

Technical Field

[0001] The present invention relates to the field of electrolytes, and more specifically to an electrolyte and its preparation process. Background Art

[0002] The preparation methods of electrolytes vary due to different battery types and application scenarios. The commonly used electrolyte preparation process usually places a certain amount of solvents, solutions, and additives in a container for mixing and reaction, and controls the temperature to meet the preparation conditions of the electrolyte. Currently, most containers for preparing electrolytes are barrel-shaped. When loading materials in a barrel-shaped container for mixing, it is difficult to mix the materials in the middle and at the edges of the barrel-shaped container, and there is a situation where the materials are difficult to react. It is not possible to load materials for easy dispersion, mixing, and temperature control. By pushing the mixed materials to move reciprocally for stirring and impact, and adjusting the material temperature from the inside and outside of an annular tubular container, the preparation speed of the electrolyte can be accelerated. Summary of the Invention

[0003] To optimize the deficiencies of the prior art, the present invention provides an electrolyte and its preparation process, which can load materials for easy dispersion, mixing, and temperature control, push the mixed materials to move reciprocally for stirring and impact, and adjust the material temperature from the inside and outside of an annular tubular container to accelerate the preparation speed of the electrolyte.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0005] An electrolyte preparation device includes a frame and a barrel I fixedly connected to the frame and provided with a feeding hole I. Both ends of the frame are fixedly connected with a pipe I, and a barrel II is fixedly connected to the two pipes I. The barrel II is coaxial with the barrel I, the diameter of the barrel I is larger than that of the barrel II, and two plates I are rotatably connected to the two ends of the barrel II and the barrel I. A plurality of blade plates are fixedly connected to the middle of the two plates I. Outer heating barrels I and II are respectively fixedly connected to the two ends of the barrel I, and an inner heating barrel is fixedly connected to the inner wall of the barrel II.

[0006] Further, a discharge hole I is provided at the lower part of the barrel I. Two annular plates I fixedly connected to the outer wall of the barrel I are provided on both sides of the discharge hole I. An annular plate II rotatably connected to the barrel I is provided between the two annular plates I. A discharge hole II is provided on the annular plate II. A converging frame is fixedly connected to one of the two annular plates I. A filter plate is slidably connected between the annular plate II and the converging frame. A groove I for accommodating the filter plate is provided on the converging frame, and a discharge hole III is provided at the lower part of the converging frame.

[0007] Further, an avoidance groove is provided at the lower part of the outer heating barrel I.

[0008] Further, a gear ring I is fixedly connected to the annular plate II, a sleeve frame is fixedly connected to the barrel I, and a gear I for driving the gear ring I to rotate is rotatably connected to the sleeve frame.

[0009] Furthermore, a ring plate III sleeving on the edge of the folding frame is fixedly connected to the gear ring I.

[0010] Furthermore, for the process of preparing the electrolyte by using the electrolyte preparation device described above, the process includes the following steps:

[0011] Step 1: Add materials into the space between barrel I and barrel II through the material adding hole I;

[0012] Step 2: Drive the materials to mix and react by rotating multiple blade plates;

[0013] Step 3: Adjust the temperature of the materials through heat exchange between the inner and outer sides of barrel I and barrel II and the inner heat barrel with the materials to prepare the electrolyte;

[0014] Step 4: Drive the ring plate II to rotate so that the material discharge hole I, the material discharge hole II, the filter plate, and the material discharge hole III coincide, and while discharging the electrolyte, conduct rough filtration to collect the electrolyte.

[0015] Furthermore, for the electrolyte prepared by the electrolyte preparation process described above, the electrolyte includes the following components in parts by weight: 82 - 85 parts of dimethyl carbonate; 10 - 12 parts of lithium hexafluorophosphate; 1 - 3 parts of vinylene carbonate, 1 - 3 parts of fluoroethylene carbonate; 2 - 4 parts of lithium bis(fluorosulfonyl)imide; 2 - 6 parts of conductive carbon black; 1 - 3 parts of phosphate ester compounds; 2 - 4 parts of lithium bis(oxalato)borate.

[0016] The beneficial effects of the electrolyte and its preparation process of the present invention are as follows: It can load materials for easy dispersion, mixing, and temperature control, stir and impact by driving the mixed materials to reciprocate, and adjust the temperature of the materials from the inside and outside of the annular tubular container, accelerating the preparation speed of the electrolyte; it can also filter the prepared electrolyte by setting a detachable filter plate at the outlet of the container; it can quickly replace and clean the filter plate for filtering the electrolyte to ensure the filtering effect on the electrolyte. Description of the Drawings

[0017] The following further elaborates on the present invention in detail in conjunction with the drawings and specific implementation methods.

[0018] Figure 1 is a schematic structural diagram of the electrolyte preparation device;

[0019] Figure 2 is a schematic structural diagram of loading and mixing materials;

[0020] Figure 3 is a schematic structural diagram of mixing materials;

[0021] Figure 4Schematic diagram of the structure for electrolyte feeding;

[0022] Figure 5 Schematic diagram of the structure for filtering electrolyte;

[0023] Figure 6 Schematic diagram of the structure for adjusting the temperature of materials;

[0024] Figure 7 Schematic diagram of the structure for promoting the fluid dispersion of temperature control.

[0025] In the figure: frame 11; barrel I 12; discharge hole I 13; ring plate I 14; pipe I 15; barrel II 16; sealing plate I 17; plate I 21; vane plate 22; notch 23; gear ring II 24; gear II 25; ring plate II 31; gear ring I 32; ring plate III 33; discharge hole II 34; filter plate 35; converging frame 36; sleeve frame 37; gear I 38; outer heating barrel I 41; avoiding groove 42; connecting pipe I 43; inner heating barrel 44; connecting pipe II 45; outer heating barrel II 46; connecting pipe III 47; connecting pipe IV 48; spiral frame 51. Detailed implementation mode

[0026] Reference Figure 1 、 2 、3 and 6, the embodiments of heating materials for mixing are described in detail:

[0027] An electrolyte preparation device includes a frame 11 and a barrel I 12 fixedly connected to the frame 11 and provided with a feeding hole I. Both ends of the frame 11 are fixedly connected with pipes I 15. Two barrels II 16 are fixedly connected to the two pipes I 15. The barrel II 16 is coaxial with the barrel I 12. The diameter of the barrel I 12 is larger than that of the barrel II 16. Two plates I 21 are rotatably connected to the two ends of the barrel II 16 and the barrel I 12. A plurality of vane plates 22 are fixedly connected to the middle parts of the two plates I 21. An outer heating barrel I 41 and an outer heating barrel II 46 are respectively fixedly connected to the two ends of the barrel I 12. An inner heating barrel 44 is fixedly connected to the inner wall of the barrel II 16.

[0028] The space between barrel I (12) and barrel II (16) is used for loading, mixing, reacting, and heating materials. Materials are added into barrel I (12) through feeding hole I. Threads are provided on feeding hole I, and a sealing cover connected by threads is provided. After adding the materials, barrel I (12) is sealed by installing the sealing cover. The diameter of barrel I (12) is between 2 times and 2.5 times the diameter of barrel II (16), which can make more full use of the space and ensure that the materials loaded in the space between barrel I (12) and barrel II (16) are more convenient to disperse. Compared with a cylindrical container loading the same weight of materials, the materials are more piled up and more difficult to mix, and the material mixing and reaction are slower. Compared with an annular space where the diameter ratio of barrel I (12) to barrel II (16) is less than 2 and loading the same materials, although the materials are more dispersed, while the materials are more dispersed, the material spacing on the inner wall circumference of barrel I (12) is larger, which is not convenient for the full movement, convergence, and mixing of the materials. At the same time, the mixed materials can also be heated from two directions, the outside of barrel I (12) and the inside of barrel II (16), to control the temperature of the mixed materials, so as to carry out stirring, dispersion, and reaction, and thus ensure the full mixing and dispersion of the materials in the space between barrel I (12) and barrel II (16), and prepare the electrolyte under temperature control. The two plates I (21) can rotate around their own axes. When the two plates I (21) rotate, they drive a plurality of blade plates (22) to rotate, so as to drive the materials to move, disperse, and mix fully. The plurality of blade plates (22) are all spiral, so as to drive the materials to move axially and radially in barrel I (12). The two plates I (21) can rotate forward and reverse around their own axes, so as to push the materials to move reciprocally axially in barrel I (12). Notches (23) are provided at the outer edges of the plurality of blade plates (22). This can prevent the plurality of blade plates (22) from separating the space between barrel I (12) and barrel II (16), resulting in the situation that the materials between adjacent blade plates (22) in barrel I (12) and barrel II (16) cannot be fully mixed. Thus, through the setting of the plurality of notches (23), relative movement occurs between the materials pushed by the plurality of blade plates (22) when they rotate. The materials at the positions corresponding to the plurality of notches (23) move more slowly than the materials pushed by the blade plates (22) at the positions without notches (23), so as to increase the relative movement speed of the materials, increase the chaos of the materials, and thus increase the mixing speed of the materials, and further accelerate the preparation speed of the electrolyte; The external heat barrel I (41), the external heat barrel II (46), and the internal heat barrel (44) exchange heat with the materials between barrel I (12) and barrel II (16) through high-temperature steam or low-temperature liquid supplied by an externally provided temperature regulating device, so as to realize the temperature control of the mixed materials.

[0029] Reference Figure 1 、 2 、4 and 5, the embodiments of collecting the electrolyte after the material reaction are described in detail:

[0030] A discharge hole Ⅰ13 is provided at the lower portion of the barrel Ⅰ12, and two ring plates Ⅰ14 fixedly connected to the outer wall of the barrel Ⅰ12 are provided on both sides of the discharge hole Ⅰ13, a ring plate Ⅱ31 rotatably connected to the barrel Ⅰ12 is provided between the two ring plates Ⅰ14, and the ring plate Ⅱ31 is provided with a discharge hole Ⅱ34, and a folding frame 36 is fixedly connected to one of the two ring plates Ⅰ14, and a filter plate 35 is slidably connected between the ring plate Ⅱ31 and the folding frame 36, and a groove Ⅰ for accommodating the filter plate 35 is provided on the folding frame 36, and a discharge hole Ⅲ is provided at the lower portion of the folding frame 36.

[0031] When the material completes the reaction, the ring plate II 31 is driven to rotate, and the ring plate II 31 rotates until the discharge hole II 34 coincides with the discharge hole I 13 to discharge the prepared electrolyte. The two ring plates I 14 can limit the ring plate II 31 to ensure that the ring plate II 31 rotates stably, and can also ensure that the discharge hole II 34 on the ring plate II 31 completely coincides with or staggers with the discharge hole I 13. When the discharge hole II 34 is completely staggered with the discharge hole I 13, the barrel I 12 is sealed, and the electrolyte passes through the discharge hole I 13 and the discharge hole II 34 and then passes through the filter plate 35 for filtration. The filter plate 35 is provided with a plurality of through holes for the electrolyte to pass through. The filtering effect of the filter plate 35 on the discharged electrolyte can also be changed by setting a filter screen on the filter plate 35. The filtered electrolyte passes through the collection frame 36 The upper part of the gathering frame 36 is an arc-shaped plate fitted with the outer wall of the ring plate II 31, and the lower part is an elliptical cylinder. The lower part can gather the electrolyte and discharge it from the lowest discharge hole III at the lower part. One side of the filter plate 35 is an arc-shaped plate fitted with the ring plate II 31, and the other side is a handle connected to the arc-shaped plate. The groove I can fully accommodate the filter plate 35, and the filter plate 35 can be quickly pulled by the handle part of the filter plate 35 to slide the filter plate 35 for cleaning and replacement. It can also be quickly installed and can also discharge the residue after the electrolyte is filtered. When the filter plate 35 is pulled out, the reciprocating rotation of the multiple blades 22 pushes the residue to reciprocate through the discharge hole I13 and the discharge hole II 34 and then fall into the gathering frame 36 for discharge, so as to collect the filtered residue.

[0032] refer to Figure 1 , 4 , 5 and 6, detailed description of the embodiment to ensure that the filter plate 35 can be quickly replaced:

[0033] The lower part of the external heat barrel Ⅰ 41 is provided with an avoidance groove 42, so that the filter plate 35 can be avoided when being pulled out and installed through the avoidance groove 42, ensuring that the filter plate 35 can be quickly pulled out and installed.

[0034] refer to Figure 1 , 4 5, detailed description of the embodiment of driving the ring plate II 31 to rotate:

[0035] A ring plate II 31 is fixedly connected with a ring gear I 32. A sleeve frame 37 is fixedly connected to the barrel I 12. A gear I 38 for driving the ring gear I 32 to rotate is rotatably connected to the sleeve frame 37. The gear I 38 is fixedly connected to the output shaft of a reduction motor I, and the reduction motor I is fixedly connected to the sleeve frame 37;

[0036] Under normal conditions when mixing the mixed materials, the discharge hole I 13 and the discharge hole II 34 are staggered, and the discharge hole I 13 on the barrel I 12 is blocked by the ring plate II 31. When discharging is required, the reduction motor I is started. The reduction motor I drives the gear I 38 to rotate. The gear I 38 meshes with and drives the ring gear I 32 to rotate. The ring gear I 32 drives the ring plate II 31 to rotate, so that the position of the discharge hole II 34 on the ring plate II 31 can be adjusted. Furthermore, the coincidence of the discharge hole II 34 on the ring plate II 31 with the discharge hole I 13 for discharging can be realized, and the barrel I 12 can be sealed by staggering.

[0037] Reference Figure 4 and 5 , a detailed description of the embodiment of the edge of the sealing and closing frame 36:

[0038] The ring gear I 32 is fixedly connected with a ring plate III 33 sleeved on the edge of the closing frame 36, so that the edge of the closing frame 36 can be blocked by the ring plate III 33, and the leakage of the materials for preparing the electrolyte can be fully prevented.

[0039] Reference Figure 1 and 3 , a detailed description of the embodiment of driving the two plates I 21 to drive the plurality of blade plates 22 to rotate:

[0040] Both of the two plates I 21 are fixedly connected with a ring gear II 24. Both sides of the frame 11 are rotatably connected with a gear II 25 for driving the corresponding ring gear II 24 to rotate. A sealing plate I 17 that fits the corresponding plate I 21 is arranged on each pipe I 15. Each gear II 25 is respectively fixedly connected to the output shaft of a reduction motor II, and the two reduction motors II are both fixedly connected to the frame 11. When the two reduction motors II are started, the two reduction motors II drive the two gears II 25 to rotate. The two gears II 25 mesh with and drive the two ring gears II 24 to rotate. The rotation of the two ring gears II 24 drives the plurality of blade plates 22 to rotate to realize the pushing of the materials and the mixing of the materials. The two reduction motors II rotate and stop synchronously to ensure the synchronous rotation of the plurality of blade plates 22. The edges of the two plates I 21 are both provided with collar rings, and the edges of the two plates I 21 are sleeved on the edge of the barrel I 12, and a rotating seal is provided to prevent the leakage of the materials. The sealing plates I 17 on the two pipes I 15 can seal the connection between the plate I 21 and the barrel II 16 to prevent the leakage of the materials from the connection between the plate I 21 and the barrel II 16.

[0041] Reference Figure 1 、 6And 7, a detailed description of an embodiment of supplying temperature-controlled fluid to the outer heating barrel I 41, the inner heating barrel 44, and the outer heating barrel II 46 and the fluid circulation:

[0042] The left side of the inner heating barrel 44 communicates with the upper part of the outer heating barrel I 41 through the connecting pipe I 43, the right side of the inner heating barrel 44 communicates with the lower part of the outer heating barrel II 46 through the connecting pipe II 45, the outer heating barrel I 41 communicates with the outer heating barrel II 46 through the connecting pipe III 47, and the connecting pipe IV 48 is provided on both the outer heating barrel I 41 and the outer heating barrel II 46. A spiral frame 51 is rotatably connected inside the inner heating barrel 44.

[0043] The two connecting pipes IV 48 communicate with a temperature regulating device provided outside. High-temperature steam or low-temperature liquid supplied by the temperature regulating device provided outside is supplied into the connecting pipe IV 48 on the outer heating barrel I 41, and then the fluid flows into the outer heating barrel I 41, then flows into the inner heating barrel 44 through the connecting pipe I 43, and flows into the outer heating barrel II 46 through the connecting pipe III 47. The outer heating barrel II 46 and the inner heating barrel 44 communicate through the connecting pipe II 45 to realize the circulation inside the outer heating barrel I 41, the inner heating barrel 44, and the outer heating barrel II 46. It can also flow back to the temperature regulating device provided outside through the connecting pipe IV 48 on the outer heating barrel II 46 to realize the fluid circulation. Circulation pumps are provided on the connecting pipe I 43, the connecting pipe II 45, and the connecting pipe III 47 to ensure the full flow of the fluid, ensure the full heat exchange of the mixed materials, and thus adjust the temperature from the inside and outside of the materials for preparing the electrolyte. The spiral frame 51 is fixedly connected to the output shaft of the reduction motor III, and the reduction motor III is fixedly connected to the inner heating barrel 44. When the reduction motor III is started, the reduction motor III drives the spiral frame 51 to rotate. The spiral frame 51 can push the fluid to disperse quickly when rotating. The reduction motor III can drive the spiral frame 51 to rotate forward and backward, so as to ensure the dispersion of the temperature-controlled fluid and ensure the temperature consistency, and thus ensure the temperature of the materials for preparing the electrolyte.

[0044] Reference Figures 1 to 7 , a detailed description of an embodiment of the process for preparing the electrolyte:

[0045] According to the process for preparing the electrolyte by the above-mentioned electrolyte preparation device, the process includes the following steps:

[0046] Step 1: Add materials into the space between the barrel I 12 and the barrel II 16 through the feeding hole I. The materials are added quantitatively to ensure the performance of the prepared electrolyte.

[0047] Step 2: Drive the materials to mix and react by the rotation of multiple vanes 22. Synchronously drive the two plates I 21 to drive the multiple vanes 22 to rotate forward and backward, so as to push the materials to move reciprocally. During the process of changing the direction of the reciprocating movement, the materials can be pushed to collide with each other or collide with the two plates I 21, accelerating the mixing speed and reaction speed of the materials.

[0048] Step 3: Adjust the temperature of the material through heat exchange between the inner and outer sides of the material in the outer heat barrel I 41, the outer heat barrel II 46 and the inner heat barrel 44 to prepare the electrolyte;

[0049] Step 4: Drive the ring plate II 31 to rotate so that the discharge hole I 13, the discharge hole II 34, the filter plate 35 and the discharge hole III coincide, and while the electrolyte is discharged, coarse filtration is carried out for the collection of the electrolyte.

[0050] Reference Figure 1 , a detailed example of the composition of the prepared electrolyte is described:

[0051] The electrolyte prepared according to the above electrolyte preparation process includes the following components in parts by weight: 82 parts of dimethyl carbonate; 10 parts of lithium hexafluorophosphate; 1 part of vinylene carbonate, 1 part of fluoroethylene carbonate; 2 parts of lithium bis(fluorosulfonyl)imide; 2 parts of conductive carbon black; 1 part of phosphate compound; 2 parts of lithium bis(oxalato)borate.

[0052] The electrolyte includes the following components in parts by weight: 83 parts of dimethyl carbonate; 11 parts of lithium hexafluorophosphate; 2 parts of vinylene carbonate, 2 parts of fluoroethylene carbonate; 3 parts of lithium bis(fluorosulfonyl)imide; 4 parts of conductive carbon black; 2 parts of phosphate compound; 3 parts of lithium bis(oxalato)borate.

[0053] The electrolyte includes the following components in parts by weight: 85 parts of dimethyl carbonate; 12 parts of lithium hexafluorophosphate; 3 parts of vinylene carbonate, 3 parts of fluoroethylene carbonate; 4 parts of lithium bis(fluorosulfonyl)imide; 6 parts of conductive carbon black; 3 parts of phosphate compound; 4 parts of lithium bis(oxalato)borate.

Claims

1. An electrolyte preparation device, characterized in that: The invention comprises a frame (11) and a barrel I (12) fixedly connected to the frame (11) and provided with a material adding hole I. Both ends of the frame (11) are fixedly connected with a tube I (15). The two tubes I (15) are fixedly connected with a barrel II (16). The barrel II (16) is coaxial with the barrel I (12). The diameter of the barrel I (12) is larger than the diameter of the barrel II (16). Two plates I (21) are rotatably connected between the barrel II (16) and the two ends of the barrel I (12). A plurality of blades (22) are fixedly connected to the middle of the two plates I (21). The two ends of the barrel I (12) are respectively fixedly connected with an external heat barrel I (41) and an external heat barrel II (46). The inner wall of the barrel II (16) is fixedly connected with an inner heat barrel (44).

2. An electrolyte preparation device according to claim 1, characterized in that: The lower part of the barrel I (12) is provided with a discharge hole I (13), and two ring plates I (14) fixedly connected to the outer wall of the barrel I (12) are provided on both sides of the discharge hole I (13), and a ring plate II (31) rotatably connected to the barrel I (12) is provided between the two ring plates I (14), and the ring plate II (31) is provided with a discharge hole II (34), and a folding frame (36) is fixedly connected to one of the two ring plates I (14), and a filter plate (35) is slidably connected between the ring plate II (31) and the folding frame (36), and a groove I for accommodating the filter plate (35) is provided on the folding frame (36), and the lower part of the folding frame (36) is provided with a discharge hole III.

3. An electrolyte preparation device according to claim 2, characterized in that: The lower part of the external heat barrel I (41) is provided with an escape groove (42).

4. The electrolyte preparation device according to claim 2, characterized in that: The ring plate II (31) is fixedly connected with a gear ring I (32), the barrel I (12) is fixedly connected with a sleeve frame (37), and the sleeve frame (37) is rotatably connected with a gear I (38) for driving the gear ring I (32) to rotate.

5. The electrolyte preparation device according to claim 4, characterized in that: The gear ring I (32) is fixedly connected with a ring plate III (33) sleeved on the edge of the folding frame (36).

6. The electrolyte preparation device according to claim 1, characterized in that: The two plates I (21) are fixedly connected with gear rings II (24), and both sides of the frame (11) are rotatably connected with gears II (25) for driving the corresponding gear rings II (24) to rotate. Each tube I (15) is provided with a sealing plate I (17) that fits the corresponding plate I (21).

7. The electrolyte preparation device according to claim 1, characterized in that: The outer edges of the plurality of blades (22) are all provided with notches (23).

8. The electrolyte preparation device according to claim 1, characterized in that: The left side of the inner heat barrel (44) is connected to the upper part of the outer heat barrel I (41) through a connecting pipe I (43), the right side of the inner heat barrel (44) is connected to the lower part of the outer heat barrel II (46) through a connecting pipe II (45), the outer heat barrel I (41) is connected to the outer heat barrel II (46) through a connecting pipe III (47), the outer heat barrel I (41) and the outer heat barrel II (46) are both provided with a connecting pipe IV (48), and a spiral frame (51) is rotatably connected inside the inner heat barrel (44).

9. A process for preparing an electrolyte by an electrolyte preparation device according to any one of claims 1 to 8, characterized in that: The process includes the following steps: Step 1: Add material into the space between barrel Ⅰ (12) and barrel Ⅱ (16) through the material adding hole Ⅰ; Step 2: Promoting material mixing and reaction by rotating a plurality of blades (22); Step 3: The external heat barrel I (41), the external heat barrel II (46) and the internal heat barrel (44) exchange heat with the material from the inside and outside of barrel I (12) and barrel II (16) to adjust the temperature of the material and prepare the electrolyte; Step 4: driving the ring plate II (31) to rotate so that the discharge hole I (13), the discharge hole II (34), the filter plate (35) and the discharge hole III overlap to discharge the electrolyte and perform coarse filtration to collect the electrolyte.

10. The electrolyte prepared by the electrolyte preparation process according to claim 9, characterized in that: The electrolyte comprises the following components in the following weight ratios: 82-85 parts of dimethyl carbonate; 10-12 parts of lithium hexafluorophosphate; 1-3 parts of vinylene carbonate; 1-3 parts of fluoroethylene carbonate; 2-4 parts of lithium bis(fluorosulfonyl)imide; 2-6 parts of conductive carbon black; 1-3 parts of phosphate compound; 2-4 parts of lithium bis(oxalatoborate).

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