Lithium ion battery assembly and preparation process of coating modified solid electrolyte film of lithium ion battery assembly

Abstract

The invention provides a lithium ion battery assembly and a preparation process of a coated modified solid electrolyte film thereof. A lithium ion battery assembly relates to the technical field of lithium ion batteries and comprises an outer shell, an inner shell, a cover plate, a lithium battery, a positioning component and a top plate, the inner shell is located in the outer shell, the bottom of the cover plate is erected on the upper surface of the inner shell, the lithium battery comprises an aluminum alloy shell, auxiliary plates and a diaphragm, and the auxiliary plates are fixedly arranged on the two sides of the aluminum alloy shell; according to the scheme, the method for preparing the solid electrolyte diaphragm through coating modification can effectively solve the problems of poor wettability of slurry and the diaphragm and failure and color development of a binder, reduces the process difficulty, and assists in industrial production of a lithium ion solid-state battery; and secondly, in the lithium battery mounting process, the auxiliary plate is downwards moved through the auxiliary plate with an inclined surface structure, a stress control guide wheel is used for carrying out stress positioning on the auxiliary plate, it is guaranteed that a user can rapidly insert and mount the lithium battery, and the lithium batteries with different sizes and lengths can be assembled through the design.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and in particular to a lithium-ion battery assembly and a process for preparing a coated modified solid electrolyte film thereof. Background Art

[0002] With the widespread application of lithium-ion batteries in the fields of power batteries and energy storage, especially in new energy vehicles, people have put forward higher requirements on the energy density and fast charging and discharging performance of lithium-ion batteries, which is accompanied by increasing safety risks.

[0003] All-solid-state lithium-ion batteries use non-flammable or non-combustible solid electrolytes to replace the flammable organic electrolytes in traditional batteries, which can effectively solve the safety problems of lithium-ion batteries and at the same time improve the battery's operating temperature range, cycle life and energy density.

[0004] Among them, oxide solid electrolytes have been widely studied for their high stability and excellent ionic conductivity. However, the current industrial preparation method for oxide solid electrolytes generally uses high-temperature sintering, which is cumbersome and energy-intensive. In addition, due to the inherent properties of oxide solid powders, it is difficult to prepare large-area, ultra-thin, dense ceramic electrolytes. Therefore, coating solid electrolyte materials on lithium-ion battery separators is also a research direction. Secondly, traditional lithium-ion electronic assemblies are mostly assembled and installed with tape, which is cumbersome and not conducive to separate installation, and is prone to safety hazards.

[0005] Therefore, it is necessary to provide a lithium-ion battery assembly and a preparation process of a coated modified solid electrolyte film to solve the above technical problems. Summary of the Invention

[0006] The present invention provides a lithium-ion battery assembly and a process for preparing a coated modified solid electrolyte film thereof, which solves the technical problems in the related art of the diaphragm in lithium batteries, such as the complicated use and installation and great safety hazards.

[0007] To solve the above technical problems, the present invention provides a lithium-ion battery assembly, comprising an outer shell, an inner shell, a cover plate, a lithium battery, a positioning assembly and a top plate; The inner shell is located inside the outer shell, and the bottom of the cover plate is mounted on the upper surface of the inner shell. The lithium battery includes an aluminum alloy shell, an auxiliary plate, and a diaphragm. The auxiliary plate is fixed on both sides of the aluminum alloy shell, and the diaphragm is fixed in the middle of the aluminum alloy shell. A negative electrode terminal and a positive electrode terminal are respectively provided on the top of the aluminum alloy shell and on the opposite side of the auxiliary plate. A bottom shell is integrally provided on the inner bottom of the aluminum alloy shell and below the diaphragm. The positioning assembly includes a mounting base and an extrusion barrel. The bottom of the mounting base is plugged into the upper surface of the inner shell. The outer wall of the extrusion barrel is installed inside the mounting base by bolts. A piston is installed inside the extrusion barrel. One end of the piston is located outside the extrusion barrel and is rotatably connected to a guide wheel. One end of the extrusion barrel is located on one side of the piston and is sealed with a hose. A connecting pipe is integrated at the outlet of the hose, and an expansion ring is integrated at the outlet of the connecting pipe.

[0008] Preferably, the bottom of the auxiliary plate is in a forty-five-degree inclined structure, and the diaphragm is made of a coated modified solid electrolyte film.

[0009] Preferably, the outer wall of the piston slides horizontally with the inner wall of the extrusion barrel through a plurality of seals, a hole larger than the negative electrode connector and the positive electrode connector is opened inside the cover plate, and the expansion ring is embedded in the hole.

[0010] Preferably, a positioning hole is provided inside the bottom shell, and a notch is provided inside the positioning hole; A locking assembly is installed on the inner bottom of the inner shell, and the locking assembly includes a rotating shaft and a connecting plate. The inner wall of the connecting plate is fixed on the outer wall of the rotating shaft, an auxiliary groove is opened inside the rotating shaft, a return spring is embedded in the top of the rotating shaft, and clamping rods are fixed on both sides of the return spring.

[0011] Preferably, the connecting plate is rotatably connected to the inner bottom of the inner shell, the outer end of the clamping rod is in a forty-five-degree inclined structure, the cross-section of the positioning hole is in a T-shaped structure, and the width of the slot is greater than the outer diameter of the clamping rod.

[0012] Preferably, it also includes a stabilizing component and a plug-in component; A cooling fan is mounted on the side wall of the outer shell by bolts, positioning rings are fixed on both sides of the inner shell, and the stabilizing assembly includes a positioning cylinder fixed to the bottom of the inner shell, and two symmetrically distributed positioning plates are slidably connected to the bottom of the positioning cylinder, and a first spring is fixed on opposite sides of the two positioning plates; The plug-in assembly includes a mounting tube fixed to the bottom of the top plate, a second spring is installed inside the mounting tube, a sliding rod is vertically slidably connected inside the mounting tube and below the second spring, and a plug-in rod is fixed to the bottom end of the sliding rod.

[0013] Preferably, the inner diameter of the positioning ring is larger than the outer diameter of the positioning tube, the top of the two positioning plates are both 45-degree inclined structures, the upper and lower ends of the second spring are fixedly connected to the top of the mounting tube and the top of the sliding rod, and the bottom end of the plug-in rod is conical.

[0014] Preferably, it also includes a sealing component; The sealing assembly includes a mounting frame and a sealing capsule, wherein the mounting frame is fixedly connected to the upper outer wall of the housing, and the sealing capsule is embedded in the mounting frame, and the outer wall of the sealing capsule is integrally provided with a first protrusion, a second protrusion, and a third protrusion; The cross section of the installation frame is L-shaped, and the lengths of the first protrusion, the second protrusion and the third protrusion increase gradually from bottom to top.

[0015] The process for preparing a coated modified solid electrolyte film comprises the following steps: S1: ball milling and coating the modifier and the solid electrolyte material, wherein the modifier is sodium dodecyl sulfate DSS and polyacrylic acid sodium salt, and the mass ratio of the modifier to the solid electrolyte material is 0.5% to 2.0%; Ball milling coating conditions include at least one of the following three: 1. Ball milling time is 9 to 12 hours; 2. Ball mill speed 300 to 500 rpm; 3. The solvent used in ball milling is an organic solvent such as isopropyl alcohol or ethanol; S2: mixing the modified oxide solid electrolyte powder and the binder in a certain proportion and dissolving them in an organic solvent, wherein the oxide solid electrolyte material is lithium lanthanum zirconium oxide (LLZO) and LLZO with doping elements, wherein the doping elements include one or more of tantalum, gallium, niobium, aluminum, silicon or magnesium; The solvent is N-methylpyrrolidone and dimethyl amide, and the binder is polyvinylidene fluoride and polyvinylidene fluoride hexafluoropropylene copolymer organic binder; S3: After thorough stirring and mixing, a dispersed and stable slurry can be obtained. The slurry is coated on the diaphragm 45 and dried to form an ultra-thin and dense solid electrolyte film. The diaphragm 45 includes one or more of PP, PE, and PET. The mass ratio of the modified solid electrolyte material in the slurry to the solvent is 75% to 95%. The particle size of the modified electrolyte powder is 300nm to 1μm. The slurry coating thickness is 1μm to 50μm. The thickness of the final formed solid electrolyte diaphragm 45 is 1 to 150μm.

[0016] Compared with related technologies, the lithium-ion battery assembly and the process for preparing the coated modified solid electrolyte film provided by the present invention have the following beneficial effects: In the market, inorganic ceramic coatings are usually introduced on lithium-ion battery separators, which is a relatively cumbersome process. The method of preparing solid electrolyte separators through coating modification can effectively solve the problems of poor wettability between slurry and separator and color development caused by binder failure, reduce the process difficulty, and facilitate the industrial production of lithium-ion solid-state batteries. Secondly, compared with the traditional tape-assembled lithium battery design, this case uses an independent inner shell for each square lithium battery to install them separately. Secondly, during the installation of the lithium battery, the auxiliary plate with an inclined structure is moved downward to control the force of the guide wheel to position the auxiliary plate, ensuring that the user can quickly plug and install the lithium battery. Secondly, such a design can also assemble lithium batteries of different sizes and lengths to ensure better compatibility. Secondly, when the lithium battery is being installed, the piston linkage controls the expansion ring to expand, thereby eliminating the installation gap between the positive and negative connectors. At the same time, during the subsequent wiring process, the user uses the expansion ring to block the terminal and the cover plate, which has good insulation properties, thereby ensuring that the lithium battery power generation work is safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0018] Figure 1 A schematic diagram of the best structure provided by the present invention; Figure 2 for Figure 1 Schematic diagram of the final assembly structure of the lithium battery shown; Figure 3 for Figure 1 The schematic diagram of the cross-sectional structure of the lithium battery shown; Figure 4 for Figure 1 Schematic diagram of the split structure of the lithium battery and inner shell shown; Figure 5 for Figure 4 The schematic diagram of the cross-sectional structure of the positioning component shown; Figure 6 This is a schematic diagram of the lithium battery and inner shell provided by the present invention before installation; Figure 7 for Figure 6 The enlarged structural diagram of point A is shown; Figure 8 for Figure 6 The schematic plan view of the lithium battery entering the inner shell; Figure 9 for Figure 8 The enlarged structural diagram of point B is shown; Figure 10 A schematic cross-sectional view of the locking assembly provided by the present invention; Figure 11A schematic diagram of the detailed internal structure of the bottom shell provided by the present invention; Figure 12 A schematic diagram of the installation plan of the inner shell, outer shell and top plate provided by the present invention; Figure 13 for Figure 12 The enlarged structural diagram of point C is shown; Figure 14 for Figure 12 Schematic diagram of the top plate and shell closure structure shown; Figure 15 for Figure 14 The enlarged schematic diagram of point D is shown; Figure 16 This is a 5000-fold SEM image of the solid electrolyte LLZTO material before and after the coating modification treatment provided by the present invention; Figure 17 This is a comparison chart of the charge and discharge cycles of a lithium symmetrical battery assembled with the LLZTO solid electrolyte film and PE separator provided by the present invention at 0.2 mA to 0.2 mA·h.

[0019] Description of Figure Numbers: 1. Shell; 2. Inner shell, 3. Positioning ring; 4. Lithium battery, 41. Aluminum alloy shell, 42. Auxiliary board, 43. Negative terminal, 44. Positive terminal, 45. Diaphragm, 46. Bottom shell, 47. Positioning hole, 48. Notch; 5. Positioning assembly, 51. Mounting seat, 52. Extruder, 53. Piston, 54. Guide wheel, 55. Hose, 56. Connecting pipe, 57. Expansion ring; 6. Locking assembly, 61. Rotating shaft, 62. Return spring, 63. Clamping rod, 64. Connecting plate, 65. Auxiliary slot; 7. Stabilizing assembly, 71. Positioning cylinder, 72. Positioning plate, 73. First spring; 8. Connecting assembly, 81. Mounting cylinder, 82. Second spring, 83. Sliding rod, 84. Connecting rod; 9. Sealing assembly, 91. Mounting frame, 92. Sealing capsule, 93. First protrusion, 94. Second protrusion, 95. Third protrusion; 10. Top plate, 11. Cooling fan, 12. Cover plate. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] The present invention provides a lithium ion battery assembly and a process for preparing a coated modified solid electrolyte film thereof.

[0022] First embodiment: Please combine Figures 1 to 11 , a lithium-ion battery assembly, comprising an outer shell 1, an inner shell 2, a cover plate 12, a lithium battery 4, a positioning component 5 and a top plate 10; The inner shell 2 is located inside the outer shell 1. The bottom of the cover plate 12 is mounted on the upper surface of the inner shell 2. The lithium battery 4 includes an aluminum alloy shell 41, an auxiliary plate 42, and a diaphragm 45. The auxiliary plate 42 is fixed to both sides of the aluminum alloy shell 41. The diaphragm 45 is fixed to the middle of the aluminum alloy shell 41. A negative terminal 43 and a positive terminal 44 are respectively provided on the top of the aluminum alloy shell 41 and on the opposite side of the auxiliary plate 42. A bottom shell 46 is integrally provided on the inner bottom of the aluminum alloy shell 41 and below the diaphragm 45. See also Figure 3 and Figure 4 The aluminum alloy shell 41 adopts a rectangular structure design as a whole, and the left and right sides of the aluminum alloy shell 41 are partitioned by the diaphragm 45, ensuring that the negative electrode material and the positive electrode material are partitioned by the diaphragm 45.

[0023] The positioning assembly 5 includes a mounting base 51 and an extrusion barrel 52. The bottom of the mounting base 51 is plugged into the upper surface of the inner shell 2. The outer wall of the extrusion barrel 52 is installed inside the mounting base 51 by bolts. A piston 53 is installed inside the extrusion barrel 52. One end of the piston 53 is located outside the extrusion barrel 52 and is rotatably connected to a guide wheel 54. One end of the extrusion barrel 52 is located on one side of the piston 53 and is sealed with a hose 55. A connecting pipe 56 is integrated at the outlet of the hose 55, and an expansion ring 57 is integrated at the outlet of the connecting pipe 56.

[0024] The bottom of the auxiliary plate 42 is in a 45-degree inclined structure, and the diaphragm 45 is made of a coated modified solid electrolyte film.

[0025] See also Figure 4 and Figure 6 Before installing the lithium battery 4, the user first needs to align the bottom of the aluminum alloy shell 41 and the top opening position of the inner shell 2. After the alignment is completed, the aluminum alloy shell 41 needs to be put down.

[0026] See also Figure 6 and Figure 7 When the aluminum alloy shell 41 is placed and moved downward, the outer walls on both sides of the aluminum alloy shell 41 will contact the guide wheel 54. At this time, the guide wheel 54 assists in rolling so that the aluminum alloy shell 41 can be smoothly placed inside the inner shell 2.

[0027] See also Figure 8 and Figure 9 : When the aluminum alloy shell 41 moves to the limit position, the bottom inclined surface of the auxiliary plate 42 will contact the guide wheel 54; See also Figure 1 and Figure 3 : When the auxiliary plate 42 contacts the guide wheel 54, the user needs to cover the cover 12 on the aluminum alloy shell 41. In the process of covering the cover 12, the user needs to align the holes on the cover 12 so that it can stably pass through the positive terminal 44 and the negative terminal 43.

[0028] Please refer again Figure 8 and Figure 9 : Then the user presses the cover plate 12 hard. At this time, the inclined surface at the bottom of the auxiliary plate 42 will be forced to resist the guide wheel 54. When the guide wheel 54 is subjected to the oblique force, it will drive the piston 53 to push to the right along the horizontal direction of the extrusion cylinder 52. At this time, the piston 53 generates a push to squeeze the gas in the extrusion cylinder 52 through the hose 55.

[0029] See also Figure 5 At this time, the gas in the hose 55 is squeezed into the expansion ring 57 through the connecting tube 56, and the expansion of the expansion ring 57 eliminates the gap between the positive terminal 44 and the negative terminal 43.

[0030] The outer wall of the piston 53 slides horizontally with the inner wall of the extrusion cylinder 52 through multiple seals. The cover plate 12 has a hole inside that is larger than the negative terminal 43 and the positive terminal 44, and the expansion ring 57 is embedded in the hole.

[0031] Understandable: From Figure 7 and Figure 9 As can be seen in the figure, a spring is provided between the piston end 53 and the extrusion cylinder 52 for connection, which can ensure that there is an initial force between the piston 53 and the extrusion cylinder 52, and can ensure that the lithium battery 4 can be reset after disassembly; Secondly, the cover plate 12 and the inner shell 2 are connected by a hose 55 . Such a design can ensure the flexibility of the cover plate 12 .

[0032] In this embodiment, a binder and an organic solvent are usually used to prepare an electrolyte slurry. The presence of alkaline groups on the surface of a garnet-type electrolyte easily causes the binder to fail and the slurry to develop color. In addition, the oily slurry prepared from the current oxide solid electrolyte material has poor wettability with the lithium-ion battery separator 45 on the market and cannot be evenly coated on the battery separator 45. In the market, an inorganic ceramic coating is usually introduced on the lithium-ion battery separator 45, and the process is relatively cumbersome. The method of preparing the solid electrolyte separator 45 by coating modification can effectively solve the problems of poor wettability between the slurry and the separator 45 and color development due to binder failure, reduce the process difficulty, and contribute to the industrial production of lithium-ion solid-state batteries. Secondly, compared with the traditional design of assembling lithium batteries 4 with tape, this case uses an independent inner shell 2 to install each square lithium battery 4 in a separated manner. Secondly, during the installation of the lithium battery 4, the auxiliary plate 42 with an inclined structure is moved downward to control the guide wheel 54 to force-position the auxiliary plate 42, ensuring that the user can quickly plug and install the lithium battery. Secondly, such a design can also assemble lithium batteries 4 of different sizes and lengths to ensure better compatibility. Secondly, when the lithium battery 4 is being installed, the piston 53 controls the expansion ring 57 to expand, thereby eliminating the installation gap between the positive terminal 44 and the negative terminal 43. At the same time, during the subsequent wiring process, the user uses the expansion ring 57 to block the terminal and the cover plate 12, which has good insulation properties, thereby ensuring that the lithium battery 4 can generate electricity more safely.

[0033] A positioning hole 47 is formed inside the bottom shell 46 , and a notch 48 is formed inside the positioning hole 47 ; A locking assembly 6 is installed at the inner bottom of the inner shell 2. The locking assembly 6 includes a rotating shaft 61 and a connecting plate 64. The inner wall of the connecting plate 64 is fixed to the outer wall of the rotating shaft 61. An auxiliary groove 65 is opened inside the rotating shaft 61. A return spring 62 is embedded in the top of the rotating shaft 61. A clamping rod 63 is fixed on both sides of the return spring 62.

[0034] The connecting plate 64 is rotatably connected to the inner bottom of the inner shell 2 . The outer end of the clamping rod 63 is a 45-degree inclined surface. The cross section of the positioning hole 47 is a T-shaped structure. The width of the notch 48 is greater than the outer diameter of the clamping rod 63 .

[0035] See also Figure 8 、 Figure 10 and Figure 11 : When the aluminum alloy shell 41 is finally installed with the inner shell 2, the bottom shell 46 will enter the interior of the locking assembly 6; When the bottom end of the positioning hole 47 contacts the inclined surface of the latch rod 63, with the pressure from above, the positioning hole 47 will continue to resist the latch rod 63, and eventually the latch rod 63 will move relatively to control the return spring 62 to form compression. When the latch rod 63 completely enters the positioning hole 47, the return spring 62 will extend to control the latch rod 63 to lock the bottom shell 46 in position.

[0036] With this design, during the installation of the lithium battery 4, the positioning and locking can be directly linked after the lithium battery 4 is installed in place, which is more convenient for the user to install and further ensures the safety of the installation of the lithium battery 4 and the inner shell 2.

[0037] Second embodiment: See also Figure 1 、 Figure 12 and Figure 13 , further comprising a stabilizing component 7 and a plug-in component 8; A cooling fan 11 is mounted on the side wall of the outer shell 1 by bolts. Positioning rings 3 are fixed on both sides of the inner shell 2. The stabilizing assembly 7 includes a positioning cylinder 71 fixed to the bottom of the outer shell 1. Two symmetrically distributed positioning plates 72 are slidably connected to the bottom of the positioning cylinder 71. First springs 73 are fixed on opposite sides of the two positioning plates 72. The plug-in assembly 8 includes a mounting tube 81 fixed to the bottom of the top plate 10, a second spring 82 is installed inside the mounting tube 81, a slide rod 83 is vertically slidably connected inside the mounting tube 81 and below the second spring 82, and a plug-in rod 84 is fixed to the bottom end of the slide rod 83.

[0038] The inner diameter of the positioning ring 3 is larger than the outer diameter of the positioning tube 71. The tops of the two positioning plates 72 are both 45-degree inclined structures. The upper and lower ends of the second spring 82 are fixedly connected to the top of the mounting tube 81 and the top of the sliding rod 83. The bottom end of the plug-in rod 84 is conical.

[0039] See also Figure 1 and Figure 12 When the inner shell 2 and the outer shell 1 are installed, it is necessary to first align the positioning rings 3 and the stabilizing components 7 on both sides of the inner shell 2, and then insert the positioning rings 3 into the stabilizing components 7, so that the inner shell 2 and the outer shell 1 form a preliminary installation position.

[0040] See also Figure 12 and Figure 13: The inner hole of the positioning ring 3 is the b value, and the outer diameter of the positioning tube 71 is the a value. When the positioning ring 3 is inserted into the positioning tube 71, the user does not need to perform precise calibration, because the b value is greater than the a value. When the positioning ring 3 enters the positioning tube 71, the user needs to force the inner shell 2 downward, and the inner diameter of the positioning ring 3 will conflict with the upper inclined surface of the two positioning plates 72. At this time, the two positioning plates 72 will move relative to each other, and the first spring 73 will be controlled to form compression during the movement. Finally, when the positioning ring 3 enters the positioning tube 71, the two positioning plates 72 adaptively expand to stabilize the force on the positioning ring 3 (the force source comes from the extension force of the first spring 73).

[0041] Then the user needs to insert the plug-in assembly 8 on the top plate 10 into the positioning tube 71. Finally, when the bottom conical surface of the plug-in rod 84 enters the upper end of the two positioning plates 72, as the top plate 10 continues to be pressed down, the plug-in rod 84 will continue to control the two positioning plates 72 to bear the force against the positioning ring 3 for the second time.

[0042] This embodiment: Compared with the traditional design, this case adopts the plug-in installation method of the positioning ring 3 and the positioning cylinder 71 to position and install the inner shell 2 and the outer shell 1, and the inner hole of the positioning ring 3 is larger than the positioning cylinder 71, which is convenient for users to quickly calibrate the plug-in and can further improve the installation speed. Compared with the traditional thread installation, it avoids cumbersome multi-hole assembly and can improve the installation efficiency. Secondly, the elastically designed positioning plate 72 makes it convenient for users to install positioning rings 3 of different sizes, thereby effectively improving the compatibility of the installation dimensions. During the installation of the top plate 10, the plug-in rod 84 in the top plate 10 will resist and control the two positioning plates 72, thereby performing secondary force positioning on the stabilized positioning plate 72, further ensuring the installation stability of the inner shell 2 and the outer shell 1.

[0043] Third embodiment: See also Figure 14 and Figure 15 , further comprising a sealing assembly 9; The sealing assembly 9 includes a mounting frame 91 and a sealing capsule 92. The mounting frame 91 is fixedly connected to the upper outer wall of the housing 1. The sealing capsule 92 is embedded in the mounting frame 91. The outer wall of the sealing capsule 92 is integrally provided with a first protrusion 93, a second protrusion 94, and a third protrusion 95. The cross section of the mounting frame 91 is L-shaped, and the lengths of the first protrusion 93 , the second protrusion 94 and the third protrusion 95 increase gradually from bottom to top.

[0044] See also Figure 13 and Figure 15: During the operation of the second embodiment, when the top plate 10 is finally installed, the bottom of the top plate 10 needs to be inserted between the outer shell 1 and the sealing bag 92. During the process of insertion from top to bottom, the top plate 10 will pass through the third protrusion 95, the second protrusion 94 and the first protrusion 93 in sequence. When passing through the third protrusion 95, the third protrusion 95 directly seals the outer wall of the top plate 10. When passing through the second protrusion 94 and the first protrusion 93, the length becomes longer in sequence. The second protrusion 94 and the first protrusion 93 will form a bend to further exert force on the top plate 10. Finally, the bottom of the top plate 10 will resist the bottom arc protrusion position of the sealing bag 92. At this time, the internal gas of the sealing bag 92 compresses and flows from bottom to top to control the third protrusion 95, the second protrusion 94 and the first protrusion 93 to expand secondary and contact the outer wall of the top plate 10.

[0045] It can be understood that the sealing capsule 92 is installed in the installation frame 91 in a sealing ring shape as a whole, and the installation frame 91 surrounds the upper end of the entire shell 1, so that an all-round sealing installation can be achieved.

[0046] This embodiment: This case is designed with a sealing bag 92 with a unique structure. When the top plate 10 is being installed, it can pass through the third protrusion 95, the second protrusion 94 and the first protrusion 93, thereby forming three kinds of force to initially seal and fix the top plate 10. Finally, the bottom of the top plate 10 will squeeze the sealing bag 92 a second time to make it expand, thereby further ensuring the installation sealing effect of the top plate 10 and the outer shell 1. Therefore, such a structure is simple to install and has a good sealing effect, ensuring that the waterproof and dustproof effect on the outer shell 1 is better, and can better protect the internal lithium battery 4.

[0047] Working principle of lithium-ion battery assembly: S1; First, you need to install and position the inner shell 2 and outer shell 1: Align the positioning rings 3 and the stabilizing assembly 7 on both sides of the inner shell 2, and then insert the positioning ring 3 into the stabilizing assembly 7. When the positioning ring 3 enters the positioning cylinder 71, the user needs to apply downward force to the inner shell 2, and the inner diameter of the positioning ring 3 will conflict with the upper inclined surfaces of the two positioning plates 72. At this time, the two positioning plates 72 will move relative to each other. During the movement, the first spring 73 is controlled to form compression. Finally, when the positioning ring 3 enters the interior of the positioning cylinder 71, the two positioning plates 72 adaptively expand to stabilize the force on the positioning ring 3. S2; Then you need to install and position the lithium battery 4 and the inner shell 2: Align the bottom of the aluminum alloy shell 41 and the top opening position of the inner shell 2. After the alignment is completed, the aluminum alloy shell 41 needs to be lowered. During the process of the aluminum alloy shell 41 being placed and moved downward, the outer walls of both sides of the aluminum alloy shell 41 will contact the guide wheels 54. At this time, the guide wheels 54 assist in rolling so that the aluminum alloy shell 41 can be smoothly placed inside the inner shell 2. Cover the aluminum alloy shell 41 with the cover plate 12. During the process of covering the cover plate 12, the user needs to align the holes on the cover plate 12 so that they can stably pass through the positive terminal 44 and the negative terminal 43. Finally, press the cover plate 12 hard so that the guide wheel 54 is forced to assist the vertical surface of the plate 42, and the installation is completed. S3; Finally, the top plate 10 and the housing 1 need to be installed and positioned: Insert the bottom of the top plate 10 between the outer shell 1 and the sealing bag 92, and press the top plate 10 downward with force. During the insertion process from top to bottom, the top plate 10 will pass through the third protrusion 95, the second protrusion 94 and the first protrusion 93 in sequence. When the top plate 10 is completely inserted into the sealing bag 92, the installation is completed.

[0048] S4; Actual application after installation: After installation, users can freely connect the power cord and use it according to their own needs. The entire assembly can be placed in a new energy vehicle as a power source, and the cooling fan 11 is mainly responsible for the heat dissipation inside the housing 1; When the inner shell 2 and the lithium battery 4 are to be disassembled, it is only necessary to rotate the rotating shaft 61 so that the latching rod 63 is rotated to the position of the notch 48 , and the bottom shell 46 and the latching rod 63 can be separated.

[0049] Fourth embodiment: The process for preparing a coated modified solid electrolyte film is used for preparing a separator 45 in a lithium-ion battery assembly, and comprises the following steps: S1: ball milling and coating the modifier and the solid electrolyte material, wherein the modifier is sodium dodecyl sulfate DSS and polyacrylic acid sodium salt, and the mass ratio of the modifier to the solid electrolyte material is 0.5% to 2.0%; Ball milling coating conditions include at least one of the following three: 1. Ball milling time is 9 to 12 hours; 2. Ball mill speed 300 to 500 rpm; 3. The solvent used in ball milling is an organic solvent such as isopropyl alcohol or ethanol; S2: mixing the modified oxide solid electrolyte powder and the binder in a certain proportion and dissolving them in an organic solvent, wherein the oxide solid electrolyte material is lithium lanthanum zirconium oxide (LLZO) and LLZO with doping elements, wherein the doping elements include one or more of tantalum, gallium, niobium, aluminum, silicon or magnesium; The solvent is N-methylpyrrolidone and dimethyl amide, and the binder is polyvinylidene fluoride and polyvinylidene fluoride hexafluoropropylene copolymer organic binder; S3: After thorough stirring and mixing, a dispersed and stable slurry can be obtained. The slurry is coated on the diaphragm 45 and dried to form an ultra-thin and dense solid electrolyte film. The diaphragm 45 includes one or more of PP, PE, and PET. The mass ratio of the modified solid electrolyte material in the slurry to the solvent is 75% to 95%. The particle size of the modified electrolyte powder is 300nm to 1μm. The slurry coating thickness is 1μm to 50μm. The thickness of the final formed solid electrolyte diaphragm 45 is 1 to 150μm.

[0050] The specific implementation is as follows: 1. Mix 240 g of tantalum-doped lithium lanthanum zirconium oxide (LLZTO) electrolyte powder and 4.8 g of sodium dodecyl sulfate in 500 mL of isopropanol and mill at 500 rpm in a planetary ball mill for 12 h. 25 g of PVDF binder and 240 g of modified LLZTO electrolyte powder were mixed in 400 g of NMP solvent and mechanically stirred for 720 min to fully mix them to prepare a solid electrolyte slurry; The prepared solid electrolyte slurry is coated on a 9 μm thick PE porous diaphragm, and the slurry coating thickness is 2 μm. After the diaphragm is dried, a solid electrolyte film can be obtained.

[0051] 2. Mix 240 g of gallium-doped lithium lanthanum zirconium oxide (Ga-LLZO) electrolyte powder and 4.8 g of sodium dodecyl sulfate in 500 mL of isopropanol and mill at 500 rpm in a planetary ball mill for 12 h. 25 g of PVDF binder and 240 g of modified Ga-LLZO electrolyte powder were mixed in 400 g of NMP solvent and mechanically stirred for 720 min to fully mix them to prepare a solid electrolyte slurry; The prepared solid electrolyte slurry is coated on a 9 μm thick PE porous diaphragm, and the slurry coating thickness is 3 μm. After the diaphragm is dried, a solid electrolyte film can be obtained.

[0052] 3. Mix 240 g of tantalum-doped lithium lanthanum zirconium oxide (LLZTO) electrolyte powder and 4.8 g of polyacrylic acid sodium salt in 500 mL of isopropanol and mill at 500 rpm in a planetary ball mill for 12 h. 25 g of PVDF binder and 240 g of modified LLZTO electrolyte powder were mixed in 400 g of NMP solvent and mechanically stirred for 720 min to fully mix them to prepare a solid electrolyte slurry; The prepared solid electrolyte slurry is coated on a 9 μm thick PE porous diaphragm, and the slurry coating thickness is 2 μm. After the diaphragm is dried, a solid electrolyte film can be obtained.

[0053] 4. Mix 240 g of tantalum-doped lithium lanthanum zirconium oxide (LLZTO) electrolyte powder and 4.8 g of polyacrylic acid sodium salt in 500 mL of isopropanol and mill at 500 rpm in a planetary ball mill for 12 h. 25 g of PVDF-HFP binder and 240 g of modified LLZTO electrolyte powder were mixed in 400 g of DMF solvent and mechanically stirred for 720 min to fully mix them to prepare a solid electrolyte slurry; The prepared solid electrolyte slurry is coated on a 9 μm thick PE porous diaphragm, and the slurry coating thickness is 2 μm. After the diaphragm is dried, a solid electrolyte film can be obtained.

[0054] 5. Mix 240 g of gallium-doped lithium lanthanum zirconium oxide (Ga-LLZO) electrolyte powder and 4.8 g of sodium dodecyl sulfate in 500 mL of isopropanol and mill at 500 rpm in a planetary ball mill for 12 h. 25 g of PVDF-HFP binder and 240 g of modified Ga-LLZO electrolyte powder were mixed in 400 g of DMF solvent and mechanically stirred for 720 min to fully mix them to prepare a solid electrolyte slurry; The prepared solid electrolyte slurry is coated on a 9 μm thick PE porous diaphragm, and the slurry coating thickness is 3 μm. After the diaphragm is dried, a solid electrolyte film can be obtained.

[0055] This method can achieve slurry stability and solve the slurry discoloration problem by adding only a small amount of modifier. It is a very simple and cost-effective method. This method avoids introducing an inorganic ceramic coating on the surface of the lithium-ion battery separator 45, can further reduce the thickness of the solid electrolyte film, and is conducive to the large-scale industrial production of solid electrolytes.

[0056] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A lithium-ion battery assembly, characterized in that: Including outer shell, inner shell, cover plate, lithium battery, positioning assembly and top plate; The inner shell is located inside the outer shell, and the bottom of the cover plate is mounted on the upper surface of the inner shell. The lithium battery includes an aluminum alloy shell, an auxiliary plate, and a diaphragm. The auxiliary plate is fixed on both sides of the aluminum alloy shell, and the diaphragm is fixed in the middle of the aluminum alloy shell. A negative electrode terminal and a positive electrode terminal are respectively provided on the top of the aluminum alloy shell and on the opposite side of the auxiliary plate. A bottom shell is integrally provided on the inner bottom of the aluminum alloy shell and below the diaphragm. The positioning assembly includes a mounting base and an extrusion barrel. The bottom of the mounting base is plugged into the upper surface of the inner shell. The outer wall of the extrusion barrel is installed inside the mounting base by bolts. A piston is installed inside the extrusion barrel. One end of the piston is located outside the extrusion barrel and is rotatably connected to a guide wheel. One end of the extrusion barrel is located on one side of the piston and is sealed with a hose. A connecting pipe is integrated at the outlet of the hose, and an expansion ring is integrated at the outlet of the connecting pipe.

2. The lithium-ion battery assembly according to claim 1, characterized in that: The bottom of the auxiliary plate is in a 45-degree inclined structure, and the diaphragm is made of a coated modified solid electrolyte film.

3. The lithium-ion battery assembly according to claim 1, characterized in that: The outer wall of the piston slides horizontally with the inner wall of the extrusion cylinder through a plurality of seals. A hole larger than the negative electrode connector and the positive electrode connector is opened inside the cover plate, and the expansion ring is embedded in the hole.

4. The lithium-ion battery assembly according to claim 1, characterized in that: A positioning hole is provided inside the bottom shell, and a notch is provided inside the positioning hole; A locking assembly is installed on the inner bottom of the inner shell, and the locking assembly includes a rotating shaft and a connecting plate. The inner wall of the connecting plate is fixed on the outer wall of the rotating shaft, an auxiliary groove is opened inside the rotating shaft, a return spring is embedded in the top of the rotating shaft, and clamping rods are fixed on both sides of the return spring.

5. The lithium-ion battery assembly according to claim 4, characterized in that: The connecting plate is rotatably connected to the inner bottom of the inner shell, the outer end of the clamping rod is in a 45-degree inclined structure, the cross section of the positioning hole is in a T-shaped structure, and the width of the slot is greater than the outer diameter of the clamping rod.

6. The lithium-ion battery assembly according to claim 1, characterized in that: Also included are stabilizing components and plug-in components; A cooling fan is mounted on the side wall of the outer shell by bolts, positioning rings are fixed on both sides of the inner shell, and the stabilizing assembly includes a positioning cylinder fixed to the bottom of the inner shell, and two symmetrically distributed positioning plates are slidably connected to the bottom of the positioning cylinder, and a first spring is fixed on opposite sides of the two positioning plates; The plug-in assembly includes a mounting tube fixed to the bottom of the top plate, a second spring is installed inside the mounting tube, a sliding rod is vertically slidably connected inside the mounting tube and below the second spring, and a plug-in rod is fixed to the bottom end of the sliding rod.

7. The lithium-ion battery assembly according to claim 7, characterized in that: The inner diameter of the positioning ring is larger than the outer diameter of the positioning tube. The tops of the two positioning plates are both 45-degree inclined structures. The upper and lower ends of the second spring are fixedly connected to the top of the mounting tube and the top of the sliding rod. The bottom end of the plug-in rod is conical.

8. The lithium-ion battery assembly according to claim 1, characterized in that: Also included is a sealing assembly; The sealing assembly includes a mounting frame and a sealing capsule, wherein the mounting frame is fixedly connected to the upper outer wall of the housing, and the sealing capsule is embedded in the mounting frame, and the outer wall of the sealing capsule is integrally provided with a first protrusion, a second protrusion, and a third protrusion; The cross section of the installation frame is L-shaped, and the lengths of the first protrusion, the second protrusion and the third protrusion increase gradually from bottom to top.

9. A process for preparing a coated modified solid electrolyte film, characterized in that: The process for preparing the coated modified solid electrolyte film is used for preparing the separator 45 in the lithium-ion battery assembly according to any one of claims 1 to 2, comprising the following steps: S1: ball milling and coating the modifier and the solid electrolyte material, wherein the modifier is sodium dodecyl sulfate DSS and polyacrylic acid sodium salt, and the mass ratio of the modifier to the solid electrolyte material is 0.5% to 2.0%; Ball milling coating conditions include at least one of the following three: 1) Ball milling time: 9 to 12 hours; 2) Ball mill speed 300 to 500 rpm; 3) The solvent used in ball milling is an organic solvent such as isopropyl alcohol or ethanol; S2: mixing the modified oxide solid electrolyte powder and the binder in a certain proportion and dissolving them in an organic solvent, wherein the oxide solid electrolyte material is lithium lanthanum zirconium oxide (LLZO) and LLZO with doping elements, wherein the doping elements include one or more of tantalum, gallium, niobium, aluminum, silicon or magnesium; The solvent is N-methylpyrrolidone and dimethyl amide, and the binder is polyvinylidene fluoride and polyvinylidene fluoride hexafluoropropylene copolymer organic binder; S3: After thorough stirring and mixing, a dispersed and stable slurry can be obtained. The slurry is coated on the diaphragm 45 and dried to form an ultra-thin and dense solid electrolyte film. The diaphragm 45 includes one or more of PP, PE, and PET. The mass ratio of the modified solid electrolyte material in the slurry to the solvent is 75% to 95%. The particle size of the modified electrolyte powder is 300nm to 1μm. The slurry coating thickness is 1μm to 50μm. The thickness of the final formed solid electrolyte diaphragm 45 is 1 to 150μm.

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