Preparation method of lithium bis (fluorosulfonyl) imide and application of lithium bis (fluorosulfonyl) imide

Abstract

The invention provides a preparation method of lithium bis (fluorosulfonyl) imide and application of lithium bis (fluorosulfonyl) imide, and the preparation method comprises the steps of (1) fluorination reaction, (2) catalytic reaction and (3) lithiation reaction. According to the method, fluoride salt is used as a fluorinating reagent, and HF is avoided, so that requirements on materials of production equipment are low, reaction conditions are mild, and large-scale industrial production is easy to carry out. The raw materials are firstly fluorinated to obtain fluorosulfonic acid isocyanate and fluorosulfonic acid, then catalytic reaction is carried out to obtain bis (fluorosulfonyl) imide, and compared with the situation that bis (fluorosulfonyl) imide is difficult to purify after being fluorinated, fluorosulfonic acid obtained through fluorination is easier to purify, so that cations in fluoride salt are less in residues in a system, and the purity of the product is improved. And the purity of the lithium bis (fluorosulfonyl) imide obtained after purification in each step is relatively high. The reaction of the three steps in the preparation method of the lithium bis (fluorosulfonyl) imide is easy to carry out, so that the yield of the obtained lithium bis (fluorosulfonyl) imide is high.

Description

technical field

[0001] The invention relates to the technical field of compound synthesis, in particular to a preparation method of lithium bisfluorosulfonimide and application of lithium bisfluorosulfonimide. Background technique

[0002] With the improvement of people's requirements for battery performance, the development of batteries with high energy density, strong environmental adaptability, high safety and fast charging capability has great theoretical and practical application prospects. Development is the key technology restricting the improvement of battery performance. Compared with lithium hexafluorophosphate, lithium bisfluorosulfonimide (LiFSI) has higher electrochemical stability and thermal stability, better adaptability to positive and negative electrode materials, excellent low temperature performance, and higher safety. It is a key high-performance electrolyte material in new energy devices such as primary lithium batteries, secondary lithium ion batterie...

Examples

preparation example Construction

[0029] The preparation method of lithium bisfluorosulfonimide of the present invention includes step (1) fluorination reaction, step (2) catalytic reaction and step (3) lithiation reaction, and the reaction route is as follows.

[0030] Preparation of fluorosulfonic acid isocyanate:

[0031]

[0032] Among them: M is a cation such as Na, K, Sb and Zn.

[0033] Preparation of fluorosulfonic acid:

[0034]

[0035] Preparation of HFSI:

[0036]

[0037] Preparation of LiFSI:

[0038]

[0039] where X is OH - , CO 3 2- isoanion

[0040] Wherein, the fluorination reaction in step (1) includes: a. reacting chlorosulfonic acid isocyanate and fluoride salt and purifying to obtain fluorosulfonic acid isocyanate; b. reacting potassium hydrogen fluoride and fuming sulfuric acid and purifying to obtain fluorosulfonic acid.

[0041] In step a, a fluorinated reagent and chlorosulfonic acid isocyanate can be added to the reaction kettle, the reaction temperature is contro...

Embodiment 1

[0047] The preparation method of lithium bisfluorosulfonimide comprises the steps:

[0048] (1) Fluorination reaction

[0049] Add 142.8g (0.81mol) of antimony trifluoride to a dry 1000ml three-necked flask, heat and stir in an oil bath, set the temperature of the water bath to a constant temperature of 70°C, and slowly dropwise add 339.6g (2.4mol) of isocyanate chlorosulfonate. ), stirred and refluxed for 48h, after the reaction was completed, the temperature was gradually raised to 100°C for atmospheric distillation, and 240 g of a colorless transparent liquid fluorosulfonic acid isocyanate fraction at 80°C was collected, with a purity of 99.9% and a yield of 80%;

[0050] To the dry 1000ml three-necked flask, add 333.3g (2.5mol of sulfur trioxide) (containing 60% sulfur trioxide) oleum, place it in an ice-water bath at 0°C and stir, slowly add 351g of potassium hydrogen fluoride (4.5mol ), stirred and refluxed for 12h, after the reaction was complete, purged with nitrogen,...

Embodiment 2

[0056] The preparation method of lithium bisfluorosulfonimide comprises the steps:

[0057] (1) Fluorination reaction

[0058] In the dry 1000ml there-necked flask, add 125.6g (1.215mol) of zinc fluoride, place it in an oil bath and heat and stir, the water bath temperature is set to 70°C, and slowly dropwise add isocyanate chlorosulfonate 339.6g (2.4mol), The reaction was stirred and refluxed for 48 hours. After the reaction was completed, the temperature was gradually raised to 100 °C for atmospheric distillation, and 234 g of a colorless and transparent liquid fluorosulfonic acid isocyanate fraction at 80 °C was collected, with a purity of 99.9% and a yield of 78%;

[0059] Add 333.3g (2.5mol sulfur trioxide) (containing 60% sulfur trioxide) oleum to a dry 1000ml three-necked flask, place it in an ice-water bath at 0°C and stir, slowly add 351g (4.5mol) of potassium hydrogen fluoride dropwise , stirred and refluxed for 14h, after the reaction was over, purged with nitrogen...

technical field

[0001] The invention relates to the technical field of compound synthesis, in particular to a preparation method of lithium bisfluorosulfonimide and application of lithium bisfluorosulfonimide. Background technique

[0002] With the improvement of people's requirements for battery performance, the development of batteries with high energy density, strong environmental adaptability, high safety and fast charging capability has great theoretical and practical application prospects. Development is the key technology restricting the improvement of battery performance. Compared with lithium hexafluorophosphate, lithium bisfluorosulfonimide (LiFSI) has higher electrochemical stability and thermal stability, better adaptability to positive and negative electrode materials, excellent low temperature performance, and higher safety. It is a key high-performance electrolyte material in new energy devices such as primary lithium batteries, secondary lithium ion batterie...

Examples

preparation example Construction

[0029] The preparation method of lithium bisfluorosulfonimide of the present invention includes step (1) fluorination reaction, step (2) catalytic reaction and step (3) lithiation reaction, and the reaction route is as follows.

[0030] Preparation of fluorosulfonic acid isocyanate:

[0031]

[0032] Among them: M is a cation such as Na, K, Sb and Zn.

[0033] Preparation of fluorosulfonic acid:

[0034]

[0035] Preparation of HFSI:

[0036]

[0037] Preparation of LiFSI:

[0038]

[0039] where X is OH - , CO 3 2- isoanion

[0040] Wherein, the fluorination reaction in step (1) includes: a. reacting chlorosulfonic acid isocyanate and fluoride salt and purifying to obtain fluorosulfonic acid isocyanate; b. reacting potassium hydrogen fluoride and fuming sulfuric acid and purifying to obtain fluorosulfonic acid.

[0041] In step a, a fluorinated reagent and chlorosulfonic acid isocyanate can be added to the reaction kettle, the reaction temperature is contro...

Embodiment 1

[0047] The preparation method of lithium bisfluorosulfonimide comprises the steps:

[0048] (1) Fluorination reaction

[0049] Add 142.8g (0.81mol) of antimony trifluoride to a dry 1000ml three-necked flask, heat and stir in an oil bath, set the temperature of the water bath to a constant temperature of 70°C, and slowly dropwise add 339.6g (2.4mol) of isocyanate chlorosulfonate. ), stirred and refluxed for 48h, after the reaction was completed, the temperature was gradually raised to 100°C for atmospheric distillation, and 240 g of a colorless transparent liquid fluorosulfonic acid isocyanate fraction at 80°C was collected, with a purity of 99.9% and a yield of 80%;

[0050] To the dry 1000ml three-necked flask, add 333.3g (2.5mol of sulfur trioxide) (containing 60% sulfur trioxide) oleum, place it in an ice-water bath at 0°C and stir, slowly add 351g of potassium hydrogen fluoride (4.5mol ), stirred and refluxed for 12h, after the reaction was complete, purged with nitrogen,...

Embodiment 2

[0056] The preparation method of lithium bisfluorosulfonimide comprises the steps:

[0057] (1) Fluorination reaction

[0058] In the dry 1000ml there-necked flask, add 125.6g (1.215mol) of zinc fluoride, place it in an oil bath and heat and stir, the water bath temperature is set to 70°C, and slowly dropwise add isocyanate chlorosulfonate 339.6g (2.4mol), The reaction was stirred and refluxed for 48 hours. After the reaction was completed, the temperature was gradually raised to 100 °C for atmospheric distillation, and 234 g of a colorless and transparent liquid fluorosulfonic acid isocyanate fraction at 80 °C was collected, with a purity of 99.9% and a yield of 78%;

[0059] Add 333.3g (2.5mol sulfur trioxide) (containing 60% sulfur trioxide) oleum to a dry 1000ml three-necked flask, place it in an ice-water bath at 0°C and stir, slowly add 351g (4.5mol) of potassium hydrogen fluoride dropwise , stirred and refluxed for 14h, after the reaction was over, purged with nitrogen...

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