WO2023241109A1

WO2023241109A1 - Preparation method for lithium bis(fluorosulfonyl)imide

Info

Publication number: WO2023241109A1
Application number: PCT/CN2023/079268
Authority: WO
Inventors: 丘善棋; 程思聪; 黄起森; 龚文林; 陈振斌
Original assignee: 时代思康新材料有限公司
Priority date: 2022-06-16
Filing date: 2023-03-02
Publication date: 2023-12-21
Also published as: CN115818591A

Abstract

A preparation method for lithium bis(fluorosulfonyl)imide, comprising: reacting an ammonia source, R(HF)_n, and SO₂F_xCl_y in an organic solvent until the reaction is finished, and then performing vacuum distillation on a reaction solution to obtain an intermediate, i.e., a bis(fluorosulfonyl)imide salt, wherein 0<n≤3, x+y=2, y≠0, n-y≥0, and R is an organic base, e.g., pyridine, methylpyridine, N-methylpyrrolidone, imidazole, trimethylamine, triethylamine, tripropylamine, and tributylamine; and reacting the bis(fluorosulfonyl)imide salt with a lithium source in a solvent, and after the reaction is finished, performing purification to obtain lithium bis(fluorosulfonyl)imide. The method improves production efficiency and product yield, and simplifies the reaction process.

Description

A kind of preparation method of lithium bisfluorosulfonimide

This application claims priority from application number 202210682454.6 submitted on June 16, 2022.

Technical field

The present application relates to the field of chemical engineering, and specifically to a preparation method of lithium bisfluorosulfonyl imide.

Background technique

Lithium bisfluorosulfonimide has the characteristics of good electrochemical stability, good hydrolysis resistance and high conductivity. It can be commonly used in electrolytes, especially in power batteries, to improve the cycle performance and rate performance of power batteries.

There are currently extensive reports on the preparation process of lithium bisfluorosulfonyl imide, but the existing preparation processes have shortcomings. For example, Chinese patent application CN111620315A discloses the following preparation method: in the first step, in the presence of ammonium fluoride, organic solvent and initial amount of sulfuryl fluoride, while slowly introducing the organic base, continue to pass the remaining sulfuryl fluoride to the reaction At the end, the reaction solution is directly distilled under reduced pressure to obtain the intermediate bisfluorosulfonyl imide salt; in the second step, in the presence of an organic solvent, add lithium oxide powder to the above intermediate bisfluorosulfonyl imide salt, filter and concentrate. , add non-aqueous poor solvent for crystallization, and obtain lithium bisfluorosulfonyl imide. The above process has problems such as extremely long reaction time and low product yield.

For this reason, the present invention is proposed.

Contents of the invention

The main purpose of the present invention is to provide a preparation method of lithium bisfluorosulfonimide, which improves production efficiency and product yield.

In order to achieve the above objects, the present invention provides the following technical solutions.

A preparation method of lithium bisfluorosulfonyl imide, including:

The ammonia source, R _· (HF) _n and SO ₂ _F ≤3, x+y=2, y≠0, ny≥0, R is an organic base;

The bisfluorosulfonimide salt is reacted with a lithium source in a solvent, and after the reaction is completed, the lithium bisfluorosulfonimide is purified.

The above preparation method of the present invention adopts four reactants and undergoes two-step reactions to obtain the product.

Compared with the prior art, the preparation method of the present invention has the following advantages:

On the one hand, changing the types of sulfonyl and fluoride salts can shorten the reaction time and complete the reaction to prepare the intermediate within 2 to 7 hours, greatly improving the production efficiency and achieving a higher yield;

On the other hand, there is no need to add part of SO ₂ F _x Cl _y in advance, which simplifies the reaction process and further improves production efficiency.

In the present invention, n can take any value between 0 and 3 except 0, and is not limited to positive integers, such as 0.5, 1, 1.5, 2, 2.5, 3, etc. Possible values for x include but are not limited to 0, 0.5, 1, 1.5, 2, etc. Possible values for y include but are not limited to 0, 0.5, 1, 1.5, 2, etc.

In some embodiments, the ammonia source includes at least one of ammonia gas, ammonium fluoride, sulfonamide, sulfamic acid, and difluorohydramine;

and / or,

R is selected from at least one selected from pyridine, methylpyridine, N-methylpyrrolidone, imidazole, trimethylamine, triethylamine, tri-n-propylamine, and tri-n-butylamine;

and / or,

The organic solvent is one or more of acetonitrile, propionitrile, isopropionitrile, diethyl ether, propyl ether, isopropyl ether, tetrahydrofuran, acetone, methyl ethyl ketone, methyl isobutyl ketone, and methyl pyrrolidone. Various solvent combinations;

and / or,

The lithium source includes at least one of lithium hydroxide, lithium carbonate, lithium nitride, and lithium oxide.

In some embodiments, the ammonia source can be any one of ammonia gas, ammonium fluoride, sulfonamide, sulfamic acid, and difluorohydramine.

In some embodiments, the ammonia source can be a mixture of ammonia gas and ammonium fluoride, or a mixture of ammonium fluoride and sulfonamide, or a mixture of sulfamic acid and difluorohydrogen amine, or a mixture of ammonium fluoride and sulfamic acid. mix.

In some embodiments, R is selected from at least one of trimethylamine, triethylamine, tri-n-propylamine, and tri-n-butylamine, and n=3.

These amines have high alkalinity and can participate in the reaction to fully absorb acid ions and chloride ions in the reaction solution and promote the forward progress of the reaction.

In some embodiments, x=0 or 1. The raw materials of SO ₂ FCl and SO ₂ Cl ₂ are easily available, and the reaction yield is high.

In some embodiments, the molar ratio of ammonia source: R·(HF) _n :SO ₂ F _x Cl _y is 1: (1～5): (2～4). When R·(HF) _n and SO ₂ F _x Cl _y are appropriately excessive, it is beneficial to maintain the forward reaction rate significantly greater than the reverse reaction rate and increase the product yield.

Taking into account comprehensive factors such as yield and cost, in some embodiments, the molar ratio of ammonia source: R·(HF) _n :SO ₂ F _x Cl _y is preferably 1: (2.5～5): (2.0～2.1) .

In some embodiments, the reaction to prepare the bisfluorosulfonyl imide salt is performed at -10 to 50°C, preferably at 20 to 35°C. The reaction rate can be increased at higher temperatures, and the product yield is high at low temperatures.

In some embodiments, the reaction time for preparing the bisfluorosulfonimide salt is Within 2 to 7 hours. The reaction time is much shorter than that of the existing technology.

In some embodiments, an organic base is also added to the reaction for preparing the bisfluorosulfonyl imide salt.

Adding organic base can fully absorb acid ions and chloride ions in the reaction solution, thereby promoting the forward reaction.

In some embodiments, the purification method is: adding a poor solvent for crystallization. The poor solvent is preferably a C5-C8 alkane, benzene, toluene, xylene, dichloromethane, dichloroethane, or trichloroethane. Alkane, tetrachloroethane, carbon tetrachloride, one or more combinations.

These poor solvents can quickly promote crystallization of the product, and at the same time, the crystal quality is high.

In some embodiments, crystal washing is also included after the crystallization. Crystallization further removes impurities. The solvent for crystallization is preferably the same as the poor solvent, followed by mutually miscible solvents.

In some embodiments, before the crystallization, the method further includes: desolventizing, filtering, and concentrating the reaction product of the bisfluorosulfonimide salt and the lithium source.

Desolvation may, on the one hand, recover usable solvents and, on the other hand, improve product purity. Removal methods include but are not limited to high temperature evaporation, low pressure, adsorption, etc.

In some embodiments, the conditions for the vacuum distillation are: material temperature 50-55°C, vacuum ≥-0.09Mpa.

In some embodiments, after the vacuum distillation, the method further includes: washing with water to obtain the bisfluorosulfonimide salt. The present invention found that washing with water not only improves the purity of the product, but also does not cause the final lithium bisfluorosulfonimide water content to be too high.

In summary, compared with the prior art, the present invention at least achieves the following technical effects:

The reaction time when preparing lithium bisfluorosulfonyl imide is shortened and the product yield is improved; at the same time, the purification steps and operating conditions are further optimized to improve the product purity.

The above description is only an overview of the technical solution of the present application. In order to have a clearer understanding of the technical means of the present application, it can be implemented in accordance with the contents of the description, and in order to To make the above and other objects, features and advantages of the present application more apparent and understandable, specific implementation modes of the present application are listed below.

Description of the drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating preferred embodiments only and are not to be construed as limiting the application. Also, the same parts are represented by the same reference numerals throughout the drawings. In the attached picture:

Figure 1 is a schematic diagram of a secondary battery according to an embodiment of the present application;

Figure 2 is an exploded view of the secondary battery according to an embodiment of the present application shown in Figure 1;

Figure 3 is a schematic diagram of a battery module according to an embodiment of the present application;

Figure 4 is a schematic diagram of a battery pack according to an embodiment of the present application;

Figure 5 is an exploded view of the battery pack according to an embodiment of the present application shown in Figure 4;

FIG. 6 is a schematic diagram of a power consumption device using a secondary battery as a power source according to an embodiment of the present application.

Explanation of reference symbols:

1 battery pack; 2 upper box; 3 lower box; 4 battery module; 5 secondary battery; 51 shell; 52 electrode assembly; 53 top cover assembly.

Detailed ways

The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only used to illustrate the technical solution of the present application more clearly, and are therefore only used as examples and cannot be used to limit the protection scope of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field belonging to this application; the terms used herein are for the purpose of describing specific embodiments only and are not intended to be used in Restricted version Application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

In the description of the embodiments of this application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying the relative importance or implicitly indicating the quantity or specificity of the indicated technical features. Sequence or priority relationship. In the description of the embodiments of this application, "plurality" means two or more, unless otherwise explicitly and specifically limited.

Reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of this application, the term "and/or" is only an association relationship describing associated objects, indicating that there can be three relationships, such as A and/or B, which can mean: A exists alone, and A exists simultaneously and B, there are three cases of B alone. In addition, the character "/" in this article generally indicates that the related objects are an "or" relationship.

In the description of the embodiments of this application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to It is more than two pieces (including two pieces).

In the description of the embodiments of this application, unless otherwise clearly stated and limited, technical terms such as "installation", "connection", "connection" and "fixing" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. Disassembly and connection, or integration; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements relation. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

The present invention is based on the following two-step reaction to obtain lithium bisfluorosulfonyl imide:

The first step, ammonia source + R·(HF)n + SO ₂ F _x Cl _y → bisfluorosulfonyl imide salt + (hydrofluoride or hydrochloride);

The second step is bisfluorosulfonimide salt + lithium source → lithium bisfluorosulfonimide + R.

The lithium bisfluorosulfonimide prepared by the process of the present invention can be used in battery electrolyte, but this does not limit the application scope of the present invention. The following only takes lithium-ion secondary batteries as an example to introduce the application range of lithium bisfluorosulfonyl imide.

In one embodiment of the present application, a secondary battery is provided.

Typically, a secondary battery includes a positive electrode plate, a negative electrode plate, an electrolyte and a separator. During the charging and discharging process of the battery, active ions are inserted and detached back and forth between the positive and negative electrodes. The electrolyte plays a role in conducting ions between the positive and negative electrodes. The isolation film is placed between the positive electrode piece and the negative electrode piece. It mainly prevents the positive and negative electrodes from short-circuiting and allows ions to pass through.

[Positive pole piece]

The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector. The positive electrode film layer includes the positive electrode active material of the first aspect of the present application.

As an example, the positive electrode current collector has two surfaces facing each other in its own thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum foil can be used. The composite current collector may include a polymer material base layer and a metal formed on at least one surface of the polymer material base layer. layer. The composite current collector can be formed by forming metal materials (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on polymer material substrates (such as polypropylene (PP), polyterephthalate It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

In some embodiments, when the secondary battery is a lithium ion battery, the cathode active material may be a cathode active material known in the art for lithium ion batteries. As an example, the cathode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials of batteries can also be used. Only one type of these positive electrode active materials may be used alone, or two or more types may be used in combination. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO ₂ ), lithium nickel oxides (such as LiNiO ₂ ), lithium manganese oxides (such as LiMnO ₂ , LiMn ₂ O ₄ ), lithium Nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1/3Co1/3Mn1/3O2 (also referred to as NCM333), LiNi _0.5 Co _0.2 Mn _0.3 O ₂ (also Can be abbreviated as NCM523), LiNi _0.5 Co=Mn _0.25 O ₂ (can also be abbreviated as NCM211), LiNi _0.6 Co _0.2 Mn _0.2 O ₂ (can also be abbreviated as NCM622), LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (can also be abbreviated as NCM622) It is at least one of NCM811), lithium nickel cobalt aluminum oxide (such as LiNi _0.85 Co _0.15 Al _0.05 O ₂ ) and its modified compounds, etc. Examples of lithium-containing phosphates with an olivine structure may include but are not limited to iron phosphate Lithium (such as LiFePO ₄ (also referred to as LFP)), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO ₄ ), composite materials of lithium manganese phosphate and carbon, lithium iron manganese phosphate, lithium iron manganese phosphate At least one composite material with carbon.

In some embodiments, when the secondary battery is a sodium ion battery, the positive electrode activity The material may be a cathode active material known in the art for sodium ion batteries. As an example, only one type of positive electrode active material may be used alone, or two or more types may be combined. Among them, the positive active material can be selected from sodium iron composite oxide (NaFeO ₂ ), sodium cobalt composite oxide (NaCoO ₂ ), sodium chromium composite oxide (NaCrO ₂ ), sodium manganese composite oxide (NaMnO ₂ ), sodium nickel Composite oxide (NaNiO ₂ ), sodium nickel titanium composite oxide (NaNi _1/2 Ti _1/2 O ₂ ), sodium nickel manganese composite oxide (NaNi _1/2 Mn _1/2 O ₂ ), sodium iron manganese composite Oxide (Na _2/3 Fe _1/3 Mn _2/3 O ₂ ), sodium nickel cobalt manganese composite oxide (NaNi _1/3 Co _1/3 Mn _1/3 O ₂ ), sodium iron phosphate compound (NaFePO ₄ ), sodium manganese phosphate compound (NaMnPO ₄ ), sodium cobalt phosphate compound (NaCoPO ₄ ), Prussian blue materials, polyanionic materials (phosphate, fluorophosphate, pyrophosphate, sulfate), etc., but this application does not Limited to these materials, the present application can also use other conventionally known materials that can be used as positive electrode active materials for sodium ion batteries.

In some embodiments, the positive electrode film layer optionally further includes a binder. As examples, the binder may include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene At least one of ethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin.

In some embodiments, the positive electrode film layer optionally further includes a conductive agent. As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive active material, conductive agent, binder and any other components in a solvent (such as N -methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector, and after drying, cold pressing and other processes, the positive electrode piece can be obtained.

[Negative pole piece]

The negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, where the negative electrode film layer includes a negative electrode active material.

As an example, the negative electrode current collector has two opposite surfaces in its own thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, copper foil can be used. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base material. The composite current collector can be formed by forming metal materials (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyterephthalate It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

In some embodiments, the negative active material may be a negative active material known in the art for batteries. As an example, the negative active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and the like. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon carbon composites, silicon nitrogen composites and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as battery negative electrode active materials can also be used. Only one type of these negative electrode active materials may be used alone, or two or more types may be used in combination.

In some embodiments, the negative electrode film layer optionally further includes a binder. The binder can be selected from styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).

In some embodiments, the negative electrode film layer optionally further includes a conductive agent. The conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

In some embodiments, the negative electrode film layer optionally includes other auxiliaries, such as thickeners (such as sodium carboxymethylcellulose (CMC-Na)) and the like.

In some embodiments, the negative electrode sheet can be prepared by dispersing the above-mentioned components for preparing the negative electrode sheet, such as negative active materials, conductive agents, binders and any other components in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode piece can be obtained.

[electrolyte]

The electrolyte plays a role in conducting ions between the positive and negative electrodes.

In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent, and the process of the present invention can be used to prepare lithium bisfluorosulfonyl imide as the electrolyte.

In some embodiments, the electrolyte optionally further includes additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain properties of the battery, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.

[Isolation film]

In some embodiments, the secondary battery further includes a separator film. There is no particular restriction on the type of isolation membrane in this application. Any well-known membrane with good chemical properties can be used. Porous structure isolation membrane with chemical stability and mechanical stability.

In some embodiments, the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation film can be a single-layer film or a multi-layer composite film, with no special restrictions. When the isolation film is a multi-layer composite film, the materials of each layer can be the same or different, and there is no particular limitation.

In some embodiments, the positive electrode piece, the negative electrode piece and the separator film can be made into an electrode assembly through a winding process or a lamination process.

In some embodiments, the secondary battery may include an outer packaging. The outer packaging can be used to package the above-mentioned electrode assembly and electrolyte.

In some embodiments, the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the secondary battery may also be a soft bag, such as a bag-type soft bag. The material of the soft bag may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, polybutylene succinate, and the like.

This application has no particular limitation on the shape of the secondary battery, which can be cylindrical, square or any other shape. For example, FIG. 1 shows a square-structured secondary battery 5 as an example.

In some embodiments, referring to FIG. 2 , the outer package may include a housing 51 and a cover 53 . The housing 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity. The housing 51 has an opening communicating with the accommodation cavity, and the cover plate 53 can cover the opening to close the accommodation cavity. The positive electrode piece, the negative electrode piece and the isolation film can be formed into the electrode assembly 52 through a winding process or a lamination process. The electrode assembly 52 is packaged in the containing cavity. The electrolyte soaks into the electrode assembly 52 . The number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.

In some embodiments, secondary batteries may be assembled into battery modules. The battery modules The number of secondary batteries contained in the block may be one or more, and those skilled in the art can select the specific number according to the application and capacity of the battery module.

Figure 3 is a battery module 4 as an example. Referring to FIG. 3 , in the battery module 4 , a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4 . Of course, it can also be arranged in any other way. Furthermore, the plurality of secondary batteries 5 can be fixed by fasteners.

Optionally, the battery module 4 may further include a housing having a receiving space in which a plurality of secondary batteries 5 are received.

In some embodiments, the above-mentioned battery modules can also be assembled into a battery pack. The number of battery modules contained in the battery pack can be one or more. Those skilled in the art can select the specific number according to the application and capacity of the battery pack.

Figures 4 and 5 show the battery pack 1 as an example. Referring to FIGS. 4 and 5 , the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box. The battery box includes an upper box 2 and a lower box 3 . The upper box 2 can be covered with the lower box 3 and form a closed space for accommodating the battery module 4 . Multiple battery modules 4 can be arranged in the battery box in any manner.

In addition, the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided by the present application. The secondary battery, battery module, or battery pack may be used as a power source for the electrical device, or may be used as an energy storage unit for the electrical device. The electric device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, and electric golf carts). , electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.

As the electric device, secondary batteries, secondary batteries, Battery module or battery pack.

Figure 6 is an electrical device as an example. The electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc. In order to meet the high power and high energy density requirements of the secondary battery for the electrical device, a battery pack or battery module can be used.

As another example, the device may be a mobile phone, a tablet, a laptop, etc. The device is usually required to be thin and light, and a secondary battery can be used as a power source.

Based on the reaction principle of lithium bisfluorosulfonyl imide described above, the present invention provides the following examples, and the types of reactants or reaction conditions of each example are different.

Example 1

1) Reaction to prepare intermediates

Add 404g triethylamine (4mol), 161g triethylamine trihydrofuride (1.0mol), 300g acetonitrile and 283g sulfuryl chloride (2.1mol) into the reactor, start stirring and cool down to -5~5℃, slowly Pour in 17g of ammonia gas (1 mol). After the addition of ammonia gas is completed, after incubation for 5 hours, the reaction solution is discharged and filtered.

2) Purification of intermediates

The reaction solution of step 1) is subjected to high vacuum and reduced pressure distillation. The conditions of reduced pressure distillation are: material temperature 50-55°C, vacuum ≥-0.09Mpa, acetonitrile and part of unreacted triethylamine are recovered, and bisfluorosulfonimide is obtained Triethylamine salt concentrate. Use deionized water to clean and remove chloride ions, fluoride ions, triethylamine hydrochloride and other impurities in the concentrated solution to obtain pure bisfluorosulfonimide triethylamine salt.

3) Preparation and purification of lithium bisfluorosulfonimide

Add 16.5g lithium oxide (0.55mol) to the above-mentioned bisfluorosulfonyl imide triethylamine salt, stir at room temperature for 3 hours, remove the filtrate, concentrate and filter, add 200g of dichloromethane to crystallize and filter, The crystals were cleaned with 100g of methylene chloride and dried under vacuum to obtain 168.5g of lithium bisfluorosulfonyl imide (0.9mol), with a yield of 90.1% (calculated as ammonia source), a purity of 97.8%, and an impurity Cl ^- content of 1.8ppm. , the impurity HF content is 33.7ppm.

Example 2

The difference from Example 1 is that triethylamine is not added, and the amount of triethylamine trihydrofuride is changed to 5 mol. The remaining steps and operating conditions are the same as Example 1.

Example 3-5

The difference from Example 2 is that the hydrofluoric acid salt of the organic base used in step 1) is different. Triethylamine trihydrofluoride is replaced by pyridine monohydrofluoride, imidazole dihydrofluoride, and sodium hydroxide respectively. , the dosage is about 5.0mol, see the table below for details.

Example 6-8

The difference from Example 2 is that the ammonia source used in step 1) is different. The ammonia gas is replaced by ammonium fluoride, sulfonamide, and sulfamic acid respectively. The dosage is about 1.0 mol. The remaining steps and operating conditions are the same as those in Example 2. Same, see table below for details.

Example 9

The difference from Example 2 is that sulfuryl chloride is replaced by sulfuryl fluoride chloride SO ₂ FCl, and the dosage is 2.1 mol.

Example 10

The difference from Example 9 is that triethylamine trihydrofluoride is replaced by pyridine monohydrofluoride.

Examples 11-14

The difference from Example 2 is that the organic solvent and dosage used in step 1) were changed, and acetonitrile was replaced with diethyl ether, tetrahydrofuran, acetone, and methylpyrrolidone respectively. The remaining steps and operating conditions were the same as in Example 2.

Example 15-16

The difference from Example 2 is that the lithium source used in step 3) is changed, and lithium oxide is replaced with lithium hydroxide and lithium carbonate respectively. The dosage is as follows.

Examples 17-19

The difference from Example 2 is that the dosage of triethylamine trihydrofuride is different. See the table below for details. The remaining steps and operating conditions are the same as Example 2.

Examples 20-22

The difference from Example 2 is that the dosage of sulfuryl chloride is different. See the table below for details. The remaining steps and operating conditions are the same as Example 2.

Examples 23-26

The difference from Example 2 is that the reaction temperature in step 1) is different. See the table below for details. The remaining steps and operating conditions are the same as Example 2.

Examples 27-30

The difference from Example 2 is that the reaction time of step 1) is different. See the following table for details. The remaining steps and operating conditions are the same as Example 2.

Example 31

The difference from Example 2 is that the conditions of the vacuum distillation in step 2) are different. See the table below for details.

Comparative example 1

The difference from Example 2 is that sulfuryl chloride is replaced by sulfuryl fluoride, and other conditions are the same as Example 2.

Comparative example 2

Add 14.8g ammonium fluoride (0.4mol) and 300g acetonitrile into a 1000ml stainless steel reaction kettle, seal the system, cool to 10°C, evacuate to 0.09MPa, and then introduce sulfuryl fluoride gas to 0.1MPa. 161.6g (1.6mol) of triethylamine was introduced within 3h. At the same time, sulfuryl fluoride was continuously introduced to 82g (0.8mol), which took a total of 13 hours. The reaction liquid is distilled under high vacuum and reduced pressure to recover acetonitrile, triethylamine and hydrofluoric acid triethylamine salt to obtain bisfluorosulfonimide triethylamine. Add 56g acetonitrile and 12g lithium oxide (0.4mol) powder to the above bisfluorosulfonimide triethylamine salt, and stir for 9 hours at room temperature. Filter, remove and concentrate the filtrate, add 130g of methylene chloride to crystallize, filter, and dry under vacuum to obtain lithium bisfluorosulfonamide as a white solid powder.

Compare the preparation results of all the above examples and comparative examples, as shown in the table below.

Preparation results of Examples and Comparative Examples

The results in Table 1 show:

Adding triethylamine to absorb tail gas can improve product purity;

Triethylamine trihydrofuride has a better comprehensive effect than other salts and can take into account both purity and yield;

If ammonium fluoride is used as the ammonia source, the yield and purity will be significantly reduced;

Sulfuryl fluoride chloride is more suitable as a reaction raw material than sulfuryl chloride, and the yield and purity will be significantly improved;

The type of organic solvent has little effect on the reaction results;

The yield of lithium carbonate as lithium salt will decrease significantly;

The dosage of triethylamine trihydrofuride has a significant impact on the yield and purity, and 5 to 6 mol is preferably used.

In summary, it can be seen that the types of raw materials participating in the chemical reaction have a significant impact on the yield and purity.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present application. The scope shall be covered by the claims and description of this application. In particular, as long as there is no structure In case of conflict, the technical features mentioned in each embodiment can be combined in any way. The application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

A method for preparing lithium bisfluorosulfonyl imide, which is characterized by including:

The ammonia source, R · (HF) n and SO 2 F ≤3, x+y=2, y≠0, ny≥0, R is an organic base;

The bisfluorosulfonimide salt is reacted with a lithium source in a solvent, and after the reaction is completed, the lithium bisfluorosulfonimide is purified.
The preparation method of lithium bisfluorosulfonyl imide according to claim 1, wherein the ammonia source includes at least one of ammonia gas, ammonium fluoride, sulfonamide, sulfamic acid, and difluorohydrogenated amine. ;

and / or,

R is selected from at least one selected from pyridine, methylpyridine, N-methylpyrrolidone, imidazole, trimethylamine, triethylamine, tri-n-propylamine, and tri-n-butylamine;

and / or,

The organic solvent is one or more solvent combinations of acetonitrile, propionitrile, isopropionitrile, diethyl ether, propyl ether, isopropyl ether, tetrahydrofuran, acetone, methyl ethyl ketone, methyl isobutyl ketone, and methyl pyrrolidone;

and / or,

The lithium source includes at least one of lithium hydroxide, lithium carbonate, lithium nitride, and lithium oxide.
The preparation method of lithium bisfluorosulfonimide according to claim 2, wherein R is selected from at least one of trimethylamine, triethylamine, tri-n-propylamine, and tri-n-butylamine, and n=3 .
The method for preparing lithium bisfluorosulfonyl imide according to any one of claims 1 to 3, wherein x=0 or 1.
The preparation method of lithium bisfluorosulfonimide according to claim 1, which is particularly The characteristic is that the molar ratio of the ammonia source: R.(HF) n : SO2FxCly is 1:(1~5):(2~4) based on the molar amount of nitrogen .
The preparation method of lithium bisfluorosulfonimide according to claim 5, characterized in that the ammonia source is based on the molar amount of nitrogen, and the ammonia source: R·(HF) n :SO 2 F x Cl y molar ratio It is 1:(2.5～5):(2.0～2.1).
The preparation method of lithium bisfluorosulfonimide according to claim 1, characterized in that the reaction for preparing the bisfluorosulfonimide salt is carried out at -10~50°C, preferably at 20~35°C. conduct;

And/or, the reaction time for preparing the bisfluorosulfonyl imide salt is 2 to 7 hours.
The method for preparing lithium bisfluorosulfonimide according to claim 1, characterized in that an organic base is also added in the reaction for preparing the bisfluorosulfonimide salt.
The preparation method of lithium bisfluorosulfonyl imide according to any one of claims 1 to 3 or any one of claims 5 to 8, characterized in that the purification method is: adding a poor solvent for crystallization, and the poor solvent is crystallized. The solvent is preferably one or more combinations of C5 to C8 alkanes, benzene, toluene, xylene, methylene chloride, dichloroethane, trichloroethane, tetrachloroethane, and carbon tetrachloride;

Preferably, crystal washing is also included after the crystallization.
The preparation method of lithium bisfluorosulfonimide according to claim 9, characterized in that, before the crystallization, it also includes: desolventizing and filtering the reaction product of the bisfluorosulfonimide salt and the lithium source, concentrate.
The preparation method of lithium bisfluorosulfonyl imide according to claim 1, characterized in that the conditions of the vacuum distillation are: material temperature 50-55°C, vacuum ≥-0.09Mpa.
Preparation method of lithium bisfluorosulfonyl imide according to claim 1 or 11 The method is characterized in that, after the vacuum distillation, it also includes: washing with water to obtain the bisfluorosulfonimide salt.