Lithium battery electrolyte injection system

Abstract

The utility model relates to the technical field of lithium ion battery electrolyte preparation, in particular to a lithium battery electrolyte injection system. The liquid injection system comprises a solvent premixing unit and an electrolyte injection unit; wherein the solvent premixing unit is used for mixing a solvent in advance; and the electrolyte injection unit is used for mixing the premixed solvent, the lithium salt and the additive and then injecting the electrolyte. According to the electrolyte injection system of the lithium battery provided by the utility model, by optimizing the electrolyte injection process, the cold chain transfer requirement and the low-temperature storage requirement can be reduced, the purchase cost and the operation cost can be reduced, and finally, the electrolyte injection system which is low in cost and high in convenience is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion battery electrolyte preparation, in particular to a lithium battery electrolyte injection system. Background Art

[0002] At present, the electrolyte injection process is as follows: the solvent, lithium salt and additives are prepared in the raw material factory. Specifically, the raw materials are mixed and put into the electrolyte preparation kettle. After mixing evenly, they are filtered, demagnetized and tested. The qualified finished electrolyte is transported to the electrolyte factory for injection (see Figure 1 ).

[0003] The above injection process is already very mature in practical applications, but in fact there are still the following problems:

[0004] 1) Electrolyte stability problem: The shelf life of the additives in the electrolyte is short. Even after mixing with the solvent, it still needs to be stored at low temperature (generally 0-10°C). Otherwise, the electrolyte will easily deteriorate and decompose, eventually affecting the performance of the battery or even making it unusable.

[0005] 2) Strict packaging requirements: The electrolyte needs to be completely sealed during transportation, and the container must be corrosion-resistant. Nitrogen protection is also required during transportation and storage, and the transportation costs and transportation equipment are expensive;

[0006] 3) Storage requirements: After the electrolyte is transported to the battery cell factory, it needs to be stored in a special storage workshop. Due to the large amount of electrolyte, the storage space and storage environment level requirements are relatively high.

[0007] The existence of the above problems leads to great restrictions in actual production, which seriously affects industrial production.

[0008] In view of this, the present utility model is proposed. Utility Model Content

[0009] The utility model provides a lithium battery electrolyte injection system, which is used to solve the above-mentioned defects in the prior art and realize a low-cost and highly convenient electrolyte injection system.

[0010] In a first aspect, the utility model provides a lithium battery electrolyte injection system, comprising a solvent premixing unit and an electrolyte injection unit; wherein the solvent premixing unit is used to mix the solvent in advance; and the electrolyte injection unit is used to mix the premixed solvent, lithium salt and additives before injection.

[0011] According to a lithium battery electrolyte injection system provided by the utility model, the solvent premixing unit includes a premixed solvent storage tank, and the premixed solvent storage tank is used to store the premixed solvent, and the premixed solvent includes dimethyl carbonate and / or diethyl carbonate.

[0012] According to a lithium battery electrolyte injection system provided by the utility model, the electrolyte injection unit includes a raw material tank, an injection device and a battery connected in sequence;

[0013] The raw material tank comprises a lithium salt tank 1, a premixed solvent tank 2 and an additive tank 3; preferably, a valve is connected between the raw material tank and the liquid injection device.

[0014] According to a lithium battery electrolyte injection system provided by the utility model, the injection device includes an electrolyte mixing tank and an injection station, the injection station includes an injection nozzle, and the outlet of the electrolyte mixing tank is connected to the inlet of the injection nozzle; the electrolyte mixing tank is used to hold the lithium battery electrolyte obtained by mixing the premixed solvent, lithium salt and additives.

[0015] According to a lithium battery electrolyte injection system provided by the utility model, the injection device includes an online mixing mechanism 4 and an injection station 6, and the injection station includes an injection nozzle 7;

[0016] The online mixing mechanism 4 includes a filling section 41 and a mixing section 42. The filling section 41 is assembled from a flange interface 43, a filler 44, a sealing ring 47 and bolts connected in sequence; the mixing section 42 is assembled from a mixer 46, a sealing ring 47, bolts and a flange interface 43 connected in sequence; the flange interface 43 of the mixing section 42 in the online mixing mechanism 4 is connected to the inlet of the liquid injection station 6.

[0017] According to a lithium battery electrolyte injection system provided by the utility model, the battery also includes a secondary cup; the secondary cup is used to store the electrolyte and transfer it to stand still, waiting for the electrolyte to infiltrate the pole piece to achieve mixed molding of the lithium battery electrolyte.

[0018] According to a lithium battery electrolyte injection system provided by the utility model, the electrolyte injection unit comprises a raw material tank, an injection device and a battery connected in sequence;

[0019] The liquid injection device comprises an electrolyte mixing tank and a liquid injection station, wherein the liquid injection station comprises a liquid injection nozzle, and the outlet of the electrolyte mixing tank is connected to the inlet of the liquid injection nozzle;

[0020] The outlet of the liquid injection nozzle is connected to the secondary cup.

[0021] According to a lithium battery electrolyte injection system provided by the utility model, the electrolyte injection unit comprises a raw material tank, an injection device and a battery connected in sequence;

[0022] The liquid injection device comprises an online mixing mechanism 4 and a liquid injection station 6, wherein the liquid injection station comprises a liquid injection nozzle 7; the online mixing mechanism 4 comprises a filling section 41 and a mixing section 42, wherein the filling section 41 is assembled by a flange interface 43, a filler 44, a sealing ring 47 and bolts connected in sequence; the mixing section 42 is assembled by a mixer 46, a sealing ring 47, bolts and a flange interface 43 connected in sequence; the flange interface 43 of the mixing section 42 in the online mixing mechanism 4 is connected to the inlet of the liquid injection nozzle 7;

[0023] The outlet of the liquid injection nozzle is connected to the secondary cup;

[0024] Preferably, a filtering and iron removal device 5 is further connected between the online mixing mechanism 4 and the liquid injection station 6 .

[0025] According to a lithium battery electrolyte injection system provided by the utility model, the premixed solvent tank 2 is connected to the flange interface 43 in the filling section 41; the lithium salt tank 1 and the additive tank 3 are connected to the filling port 45 in the filling section 41.

[0026] According to a lithium battery electrolyte injection system provided by the utility model, the injection unit comprises a raw material tank, an injection device and a battery connected in sequence;

[0027] The liquid injection device comprises a liquid injection station, and the liquid injection station comprises a liquid injection nozzle;

[0028] The outlet of the liquid injection nozzle is connected to the secondary cup.

[0029] Based on this, the technical solution of the utility model has the following advantages:

[0030] The utility model provides a lithium battery electrolyte injection system, which can reduce cold chain transportation requirements, low-temperature storage requirements, and reduce procurement costs and operating costs by optimizing the production process, and ultimately realize a low-cost and highly convenient electrolyte injection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is the electrolyte injection flow chart of the prior art mentioned in the background technology;

[0033] Figure 2 This is a lithium-ion battery electrolyte injection flow chart provided by the utility model;

[0034] Figure 3 This is a schematic diagram of electrolyte injection for a lithium-ion battery provided by an embodiment of the utility model;

[0035] Figure 4 It is a cross-sectional view of an online mixing mechanism provided by an embodiment of the utility model; wherein FIG. a is a cross-sectional view of the online mixing mechanism in an assembled state; and FIG. b is a cross-sectional view of the flange interface, the filler, the mixer and the sealing ring in a dispersed state;

[0036] Figure 3 Description of the drawings:

[0037] 1: lithium salt tank; 2: premixed solvent tank; 3: additive tank; 4: online mixing mechanism; 5: filtering and iron removal device; 6: liquid injection station; 7: liquid injection nozzle; 8: battery.

[0038] Figure 4 Description of the drawings:

[0039] 41: filling section; 42: mixing section; 43: flange interface; 44: filler; 45: filling port; 46: mixer; 47: sealing ring. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0041] At present, although the electrolyte production process of the existing technology has problems such as storage, packaging and transportation, since the production process first mixes additives with solvents and then stores and transports them at low temperatures, it is beneficial to improve the stability of the electrolyte, and thus can effectively guarantee the performance of the final battery. Therefore, the above problems are often easily overlooked. At this point, the production process is already very mature and difficult to change easily.

[0042] The above-mentioned problem was noticed in the early stage of research and development of the utility model, and it was thought of transporting the solvent, additives and lithium salt to the battery cell factory before mixing, thus avoiding the problem of high production and operation costs caused by ensuring the stability of the electrolyte; but the concentrations of DMC and DEC in the solvent were 100% before the mixed solvent was configured, and it was necessary to apply for relevant administrative procedures as hazardous chemicals. The fact is that currently few battery cell factories have the qualifications to produce hazardous chemicals, and are therefore restricted by relevant safety administrative licensing procedures.

[0043] Based on this, the utility model optimizes the production process so that when producing the electrolyte, it first passes through a solvent premixing unit, which is used to mix the solvent in advance to reduce the content of DMC or DEC in the solvent. It is not subject to the restrictions of relevant safety administrative licensing procedures, thereby greatly reducing production costs and solving the problem of battery cell factories having no production qualifications.

[0044] Based on this, the utility model provides a lithium battery electrolyte injection system, which includes a solvent premixing unit and an electrolyte injection unit; wherein the solvent premixing unit is used to mix the solvent in advance; and the electrolyte injection unit is used to mix the premixed solvent, lithium salt and additives before injection.

[0045] According to a preferred embodiment provided by the utility model, the solvent premixing unit comprises a premixed solvent storage tank, and the premixed solvent storage tank is used to store the premixed solvent, and the premixed solvent comprises dimethyl carbonate and / or diethyl carbonate.

[0046] Preferably, the premixed solvent further comprises one or more of ethyl methyl carbonate, propylene carbonate and ethylene carbonate.

[0047] According to a preferred embodiment provided by the utility model, the electrolyte injection unit comprises a raw material tank, an injection device and a battery connected in sequence;

[0048] The raw material tank includes a lithium salt tank 1, a premixed solvent tank 2 and an additive tank 3; preferably, a valve is connected between the raw material tank and the liquid injection device, and those skilled in the art can also adjust the number of lithium salt tanks 1 and additive tanks 3 according to needs to adjust the types and proportions of lithium salts and additives.

[0049] In the utility model, the lithium salt tank is used to contain lithium salt, and the lithium salt includes one or more of LiPF6, LiF, LiCl and LiFSI.

[0050] In the utility model, the additive tank is used to contain additives, and the additives include one or more of vinyl sulfate, methylene disulfonate, fluoroethylene carbonate and vinylene carbonate.

[0051] According to a preferred embodiment provided by the utility model, the injection device includes an electrolyte mixing tank and an injection station, the injection station includes an injection nozzle, and the outlet of the electrolyte mixing tank is connected to the inlet of the injection nozzle; the electrolyte mixing tank is used to hold the lithium battery electrolyte obtained by mixing the premixed solvent, lithium salt and additives.

[0052] According to a preferred embodiment provided by the utility model, the liquid injection device comprises an online mixing mechanism 4 and a liquid injection station 6, and the liquid injection station comprises a liquid injection nozzle 7;

[0053] The online mixing mechanism 4 includes a filling section 41 and a mixing section 42. The filling section 41 is assembled from a flange interface 43, a filler 44, a sealing ring 47 and bolts connected in sequence; the mixing section 42 is assembled from a mixer 46, a sealing ring 47, bolts and a flange interface 43 connected in sequence; the flange interface 43 of the mixing section 42 in the online mixing mechanism 4 is connected to the inlet of the liquid injection station 6.

[0054] Specifically, the two ends of the online mixing mechanism 4 adopt connecting flange interfaces 43 to realize one inlet and one outlet; the middle part is equipped with any number of fillers 44 and mixers 46 for assembly.

[0055] The filler 44 and the mixer 46 have similar appearance and structure, and the cross section is a structure with large ends and a small middle. The difference between the filler 44 and the mixer 46 is that the filler 44 has an additional material filling port 45 .

[0056] According to a preferred embodiment provided by the utility model, the battery further comprises a secondary cup; the secondary cup is used to store electrolyte and transfer it to stand still, waiting for the electrolyte to infiltrate the pole piece, thereby achieving mixed molding of the lithium battery electrolyte.

[0057] According to a preferred embodiment provided by the utility model, the electrolyte injection unit comprises a raw material tank, an injection device and a battery connected in sequence;

[0058] The liquid injection device comprises an electrolyte mixing tank and a liquid injection station, wherein the liquid injection station comprises a liquid injection nozzle, and the outlet of the electrolyte mixing tank is connected to the inlet of the liquid injection nozzle;

[0059] The outlet of the liquid injection nozzle is connected to the secondary cup.

[0060] According to a preferred embodiment provided by the utility model, the electrolyte injection unit comprises a raw material tank, an injection device and a battery connected in sequence;

[0061] The liquid injection device comprises an online mixing mechanism 4 and a liquid injection station 6, wherein the liquid injection station comprises a liquid injection nozzle 7; the online mixing mechanism 4 comprises a filling section 41 and a mixing section 42, wherein the filling section 41 is assembled by a flange interface 43, a filler 44, a sealing ring 47 and bolts connected in sequence; the mixing section 42 is assembled by a mixer 46, a sealing ring 47, bolts and a flange interface 43 connected in sequence; the flange interface 43 of the mixing section 42 in the online mixing mechanism 4 is connected to the inlet of the liquid injection nozzle 7;

[0062] The outlet of the liquid injection nozzle is connected to the secondary cup;

[0063] Preferably, a filtering and iron removal device 5 is further connected between the online mixing mechanism 4 and the liquid injection station 6 .

[0064] According to a preferred embodiment provided by the utility model, the premixed solvent tank 2 is connected to the flange interface 43 in the filling section 41; the lithium salt tank 1 and the additive tank 3 are connected to the filling port 45 in the filling section 41.

[0065] The utility model finds that the premixed solvent is injected from the flange interface 43, and the lithium salt and additive are injected from the filling port 45, which is beneficial for the solvent to drive the lithium salt and additive to flow and realize online mixing during the flow process; combined with the multiple variable diameter settings of the online mixing structure, the fluid can be pressurized and released during the flow process, which is more conducive to the mixing of the electrolyte and mixing uniformity.

[0066] According to a preferred embodiment provided by the utility model, the liquid injection unit comprises a raw material tank, a liquid injection device and a battery connected in sequence;

[0067] The liquid injection device comprises a liquid injection station, and the liquid injection station comprises a liquid injection nozzle;

[0068] The outlet of the liquid injection nozzle is connected to the secondary cup.

[0069] In the specific implementation process, when the above-mentioned liquid injection system is used for mixing and liquid injection in a battery cell factory, mixing and injection can be performed immediately.

[0070] As a preferred embodiment of the utility model, first, when mixing and injecting in the battery cell factory, the premixed solvent, lithium salt and additive can be mixed in the electrolyte mixing tank and then directly injected into the battery through the injection nozzle of the injection station;

[0071] As a preferred embodiment of the utility model, the second embodiment is to eliminate the mixing step of the mixing tank during mixing and injection in the battery cell factory, and mix the premixed solvent, lithium salt and additive through the online mixing mechanism 4, and the outlet of the online mixing mechanism 4 is connected to the injection station 6 to achieve online mixing and injection of the electrolyte during circulation; wherein the injection station 6 includes an injection nozzle 7;

[0072] Further preferably, in the first and second liquid injection methods, the liquid injection nozzle 7 is injected into the battery 8 through the secondary cup on the battery 8, and can be directly injected into the battery or directly injected into the secondary cup of the battery.

[0073] The third method is to directly inject the electrolyte into the secondary cup on the battery through the injection nozzle during mixing and injection in the battery cell factory. The secondary cup and the battery are then transferred and left to stand together to wait for the electrolyte to soak the electrode. The electrolyte is then injected into the secondary cup step by step according to the components, and the electrolyte is mixed and formed in the secondary cup.

[0074] Further preferably, for the above-mentioned second and third injection methods, those skilled in the art can select a specific mixing order and form according to actual conditions. For example, part of the premixed solvent can be first mixed with the lithium salt and the additive to obtain a lithium salt solution and an additive solution, respectively, to facilitate the addition of the lithium salt and the additive, which is not limited here.

[0075] In the present invention, those skilled in the art can apply the above-mentioned injection system to primary injection and secondary injection according to actual conditions, wherein the injection flow chart is shown in FIG. Figure 2 .

[0076] Unless otherwise specified, all raw materials used in the examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0077] Example

[0078] This embodiment first provides a lithium ion battery electrolyte injection system, and the specific injection schematic diagram is shown in Figure 3 , which includes a solvent premixing unit and an electrolyte injection unit;

[0079] Among them, the solvent premixing unit is carried out in the raw material factory and is used to mix the solvent in advance; the electrolyte injection unit is carried out in the battery cell factory and is used to mix the premixed solvent, lithium salt and additives and then directly inject them into the lithium battery.

[0080] The electrolyte injection unit comprises a raw material tank, an injection device and a battery 8 connected in sequence;

[0081] Among them, the raw material tank includes a lithium salt tank 1, an additive tank 3 and a premixed solvent tank 2. A valve is connected between each of the raw material tanks and the injection device. Technicians in this field can also adjust the number of lithium salt tanks 1 and additive tanks 3 according to needs to adjust the types and proportions of lithium salts and additives.

[0082] The liquid injection device comprises an online mixing mechanism 4, a filtering and iron removal device 5 and a liquid injection station 6 connected in sequence; the cross-sectional views of the online mixing mechanism 4 in the assembled state and the dispersed state are shown in FIG. Figure 4 It includes a filling section 41 and a mixing section 42. The filling section 41 is assembled by a flange interface 43, a filler 44, a sealing ring 47 and bolts connected in sequence; the mixing section 42 is assembled by a mixer 46, a sealing ring 47, bolts and a flange interface 43 connected in sequence; the flange interface 43 of the mixing section 42 is connected to the inlet of the liquid injection station 6.

[0083] Specifically, the two ends of the online mixing mechanism 4 adopt connecting flange interfaces 43 to realize one inlet and one outlet; the middle part is equipped with any number of fillers 44 and mixers 46 for assembly.

[0084] The filler 44 and the mixer 46 have similar appearance and structure, and the cross section is a structure with large ends and a small middle. The difference between the filler 44 and the mixer 46 is that the filler 44 has an additional material filling port 45 .

[0085] In this embodiment, the diameter of the filling port 45 is 10 mm, the maximum diameter of the inlet and the outlet is 40 mm, and the minimum diameter of the inlet and the outlet is 20 mm.

[0086] When in use, the premixed solvent is injected from the inlet flange interface 43, and the lithium salt and additives are injected from the filling port 45; finally, the premixed solvent and different lithium salts and additives are mixed in the filling section 41, and mixed by continuous volume changes in the mixing section 42, and finally the evenly mixed liquid flows out from the outlet flange interface 43. The multi-stage variable diameter setting of the online mixing mechanism can make the pressure and flow rate of the passing fluid in different cavities continuously change through repeated expansion and contraction of the volume, so as to better achieve the mixing effect, ensure the consistency of the electrolyte, and further improve the capacity retention rate of the battery compared with other injection equipment.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A lithium battery electrolyte injection system, characterized in that: It comprises a solvent premixing unit and an electrolyte injection unit; wherein the solvent premixing unit is used to mix the solvent in advance; and the electrolyte injection unit is used to mix the premixed solvent, lithium salt and additives before injection.

2. The lithium battery electrolyte injection system according to claim 1, characterized in that: The solvent premixing unit comprises a premixed solvent storage tank, and the premixed solvent storage tank is used to store a premixed solvent, and the premixed solvent comprises dimethyl carbonate and / or diethyl carbonate.

3. The lithium battery electrolyte injection system according to claim 1 or 2, characterized in that: The electrolyte injection unit includes a raw material tank, an injection device and a battery connected in sequence; The raw material tank comprises a lithium salt tank (1), a premixed solvent tank (2) and an additive tank (3).

4. The lithium battery electrolyte injection system according to claim 3, characterized in that: The liquid injection device comprises an electrolyte mixing tank and a liquid injection station. The liquid injection station comprises a liquid injection nozzle. The outlet of the electrolyte mixing tank is connected to the inlet of the liquid injection nozzle.

5. The lithium battery electrolyte injection system according to claim 3, characterized in that: The liquid injection device comprises an online mixing mechanism (4) and a liquid injection station (6), wherein the liquid injection station comprises a liquid injection nozzle (7); The online mixing mechanism (4) comprises a filling section (41) and a mixing section (42); the filling section (41) is assembled from a flange interface (43), a filler (44), a sealing ring (47) and bolts connected in sequence; the mixing section (42) is assembled from a mixer (46), a sealing ring (47), bolts and a flange interface (43) connected in sequence; the flange interface (43) of the mixing section (42) in the online mixing mechanism (4) is connected to the inlet of the liquid injection nozzle (7).

6. The lithium battery electrolyte injection system according to claim 3, characterized in that: The battery also includes a secondary cup; the secondary cup is used to store the electrolyte and transfer it to stand still, waiting for the electrolyte to soak the pole piece, so as to achieve mixed molding of the lithium battery electrolyte.

7. The lithium battery electrolyte injection system according to claim 6, characterized in that: The electrolyte injection unit comprises a raw material tank, an injection device and a battery connected in sequence; The liquid injection device comprises an electrolyte mixing tank and a liquid injection station, wherein the liquid injection station comprises a liquid injection nozzle, and the outlet of the electrolyte mixing tank is connected to the inlet of the liquid injection nozzle; The outlet of the liquid injection nozzle is connected to the secondary cup.

8. The lithium battery electrolyte injection system according to claim 6, characterized in that: The electrolyte injection unit comprises a raw material tank, an injection device and a battery connected in sequence; The liquid injection device comprises an online mixing mechanism (4) and a liquid injection station (6), wherein the liquid injection station comprises a liquid injection nozzle (7); the online mixing mechanism (4) comprises a filling section (41) and a mixing section (42), wherein the filling section (41) is assembled from a flange interface (43), a filler (44), a sealing ring (47) and bolts connected in sequence; the mixing section (42) is assembled from a mixer (46), a sealing ring (47), bolts and a flange interface (43) connected in sequence; the flange interface (43) of the mixing section (42) in the online mixing mechanism (4) is connected to the inlet of the liquid injection nozzle (7); The outlet of the liquid injection nozzle is connected to the secondary cup.

9. The lithium battery electrolyte injection system according to claim 8, characterized in that: The premixed solvent tank (2) is connected to the flange interface (43) in the filling section (41); the lithium salt tank (1) and the additive tank (3) are connected to the filling port (45) in the filling section (41).

10. The lithium battery electrolyte injection system according to claim 6, characterized in that: The liquid injection unit comprises a raw material tank, a liquid injection device and a battery connected in sequence; The liquid injection device comprises a liquid injection station, and the liquid injection station comprises a liquid injection nozzle; The outlet of the liquid injection nozzle is connected to the secondary cup.

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