A kind of lithium difluoroboric acid condensate deacidification and dewatering device

Abstract

The utility model relates to the technical field of electrolyte additive synthesis, specifically relates to a kind of lithium difluoroborate oxalate condensate deacidification and water removal device, including reaction kettle, the reaction kettle top is separately connected with lithium difluoroborate oxalate condensate storage tank and triethanolamine storage tank, the reaction kettle bottom is connected with bag filter, the bag filter bottom is connected with fixed bed molecular sieve filter, the fixed bed molecular sieve filter bottom is connected with dimethyl carbonate storage tank, the bag filter top is connected with double-cone dryer, and the double-cone dryer bottom is connected with triethanolamine salt storage tank.The utility model not only realizes the recovery of dimethyl carbonate, but also carries out drying and recovery to triethanolamine salt through double-cone dryer, improves the utilization of raw materials, reduces production cost, and meets the concept of green chemistry and sustainable development.

Description

Technical Field

[0001] This utility model relates to the field of electrolyte additive synthesis technology, specifically to a device for deacidifying and dewatering lithium difluorooxalate borate condensate. Background Technology

[0002] In recent years, China's lithium-ion battery industry has experienced explosive growth, not only ranking first in global production volume but also accelerating its technological iteration. Against this backdrop, the performance requirements for electrolytes—the "blood" of batteries—and their core components—additives—have been raised to unprecedented levels. High-performance electrolyte additives are key to optimizing overall battery performance. They effectively suppress initial capacity decay, improve first-discharge efficiency, significantly reduce the risk of battery swelling at high temperatures, and ultimately greatly improve charge / discharge rate performance and cycle life, directly impacting battery energy density, safety, and durability.

[0003] Among numerous high-performance additives, lithium difluorooxalate borate (LiDFOB) stands out due to its superior overall performance. It not only endows lithium-ion batteries with excellent high and low temperature adaptability (ensuring stable operation under extreme cold and heat) and outstanding thermal stability (improving safety thresholds), but also possesses good ionic conductivity (enhancing charge and discharge efficiency) and cycle performance (extending battery life), while supporting a wider operating temperature range, making it one of the key materials for improving the performance of next-generation batteries.

[0004] However, the mainstream process for large-scale industrial production of lithium difluorooxalate borate (LiDFOB) requires the reaction mixture to be dissolved in an organic solvent (such as dimethyl carbonate, DMC) and then concentrated. After the critical concentration and recrystallization process, when the system temperature decreases, high-boiling-point acidic substances condense into the liquid phase along with the solvent, resulting in a large amount of acidic lithium difluorooxalate borate condensate.

[0005] In the production process of lithium difluorooxalate borate (LiDFOB), dimethyl carbonate (DMC) in the acidic lithium difluorooxalate borate condensate usually needs to be recycled. These condensates typically contain unreacted raw materials (such as oxalic acid, boric acid, or their derivatives), reaction byproduct acids (such as hydrofluoric acid HF), and other acidic impurities introduced during the process. Due to their strong acidity and complex composition, direct recycling and storage would not only severely corrode equipment and increase maintenance costs, but also face the challenges of increasingly stringent environmental regulations and rising disposal costs. Utility Model Content

[0006] To address the shortcomings of existing technologies, this invention provides a device for removing acid and water from lithium difluorooxalate borate condensate.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows: a device for removing acid and water from lithium difluorooxalate-borate condensate, comprising a reaction vessel, wherein a lithium difluorooxalate-borate condensate storage tank and a triethanolamine storage tank are respectively connected to the top of the reaction vessel, a bag filter is connected to the bottom of the reaction vessel, a fixed-bed molecular sieve filter is connected to the bottom of the bag filter, a dimethyl carbonate storage tank is connected to the bottom of the fixed-bed molecular sieve filter, a double-cone dryer is connected to the top of the bag filter, and a triethanolamine salt storage tank is connected to the bottom of the double-cone dryer.

[0008] Furthermore, a transfer pump one is installed between the lithium difluorooxalate-borate condensate storage tank and the reactor, a transfer pump two is installed between the triethanolamine storage tank and the reactor, a transfer pump three is installed between the bag filter and the fixed-bed molecular sieve filter, and a transfer pump four is installed between the fixed-bed molecular sieve filter and the dimethyl carbonate storage tank.

[0009] Furthermore, a heat transfer medium channel for temperature control is provided on the outside of the reactor.

[0010] Furthermore, the reaction temperature inside the reactor is 20°C.

[0011] Furthermore, a heat medium channel for temperature control is provided on the outside of the double cone dryer.

[0012] Furthermore, the reaction temperature inside the double-cone dryer is 120°C.

[0013] Furthermore, a heat medium channel for temperature control is provided on the outside of the fixed-bed molecular sieve filter.

[0014] Furthermore, the reactor is equipped with a stirring paddle inside, and a motor for controlling the rotation of the stirring paddle is installed on the top of the reactor.

[0015] Furthermore, the filtration accuracy of the bag filter is 0.1 to 0.5 micrometers.

[0016] The beneficial effects achieved by this utility model are as follows:

[0017] 1. This invention utilizes the thorough mixing and reaction of triethanolamine with lithium difluorooxalate borate condensate in a reaction vessel to effectively neutralize and remove acidic substances (such as hydrofluoric acid HF) from the condensate, generating triethanolamine salt. The fixed-bed molecular sieve filter further removes moisture from dimethyl carbonate, ensuring that the recovered dimethyl carbonate meets reuse standards. This not only achieves the recovery of dimethyl carbonate but also dries and recovers triethanolamine salt using a double-cone dryer, improving raw material utilization, reducing production costs, and aligning with the principles of green chemistry and sustainable development.

[0018] 2. By removing acidic substances and moisture from the condensate, this invention reduces the risk of equipment corrosion and fundamentally eliminates the severe corrosion of downstream pipelines, storage tanks (especially dimethyl carbonate storage tanks), and the entire recovery system caused by acidic condensate. This significantly extends equipment life, reduces maintenance costs and safety risks. At the same time, the recovered dimethyl carbonate and triethanolamine salt can be reused, reducing waste emissions and realizing the resource utilization of acidic waste instead of treating it as hazardous waste, thus greatly reducing environmental pressure and disposal costs.

[0019] 3. This utility model has a compact structure, with close connections between its components, and is easy to operate. It not only saves space but also improves work efficiency and reduces operational difficulty and labor costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0021] The markings in the diagram are as follows: 1. Lithium difluorooxalate-borate condensate storage tank; 2. Triethanolamine storage tank; 3. Dimethyl carbonate storage tank; 4. Triethanolamine salt storage tank; 5. Reactor; 6. Bag filter; 7. Fixed bed molecular sieve filter; 8. Double cone dryer; 9. Transfer pump one; 10. Transfer pump two; 11. Transfer pump three; 12. Transfer pump four. Detailed Implementation

[0022] To better understand the purpose, structure, and function of this utility model, the following description, in conjunction with the accompanying drawings, provides a more detailed account of the acid and water removal device for lithium difluorooxalate borate condensate.

[0023] like Figure 1 As shown, a device for removing acid and water from lithium difluorooxalate-borate condensate includes a reaction vessel 5. A lithium difluorooxalate-borate condensate storage tank 1 is connected to one side of the top of the reaction vessel 5 via a pipe. The lithium difluorooxalate-borate condensate in the storage tank 1 enters the reaction vessel 5 through a pipe. A triethanolamine storage tank 2 is connected to the other side of the top of the reaction vessel 5 via a pipe. Triethanolamine in the storage tank 2 enters the reaction vessel 5 through a pipe. The triethanolamine reacts with the lithium difluorooxalate-borate condensate to remove acidic substances from the condensate. A bag filter 6 is connected to the bottom of the reaction vessel 5 via a pipe. A dimethyl carbonate storage tank 3 is connected to the bottom of the bag filter 6 via a pipe. A double-cone dryer 8 is connected to the top of the bag filter 6 via a pipe. A triethanolamine salt storage tank 4 is connected to the bottom of the double-cone dryer 8 via a pipe.

[0024] A transfer pump 9 is installed between the lithium difluorooxalate-borate condensate storage tank 1 and the reactor 5, which transports the lithium difluorooxalate-borate condensate from the storage tank 1 to the reactor 5. A transfer pump 10 is installed between the triethanolamine storage tank 2 and the reactor 5, which transports the triethanolamine from the storage tank 2 to the reactor 5. A transfer pump 11 is installed between the bag filter 6 and the fixed-bed molecular sieve filter 7, which transports the deacidified dimethyl carbonate from the bag filter 6 to the fixed-bed molecular sieve filter 7. A transfer pump 12 is installed between the fixed-bed molecular sieve filter 7 and the dimethyl carbonate storage tank 3, which transports the deacidified and dehydrated dimethyl carbonate from the fixed-bed molecular sieve filter 7 to the dimethyl carbonate storage tank 3.

[0025] A stirring paddle is installed inside the reactor 5. A motor is installed at the top center of the reactor 5 to control the rotation of the stirring paddle. When the motor is started, it drives the stirring paddle to rotate, which fully mixes the triethanolamine and lithium difluorooxalate borate condensate in the reactor 5. This facilitates the full reaction of the acidic substances in the lithium difluorooxalate borate condensate with the triethanolamine, achieving the best acid removal effect.

[0026] A heat medium channel for temperature control is provided on the outside of the reactor 5. The heat medium flows through the heat medium channel on the outside of the reactor 5 to control the reaction temperature inside the reactor 5 to 20℃. 20℃ is the optimal reaction temperature for lithium difluorooxalate borate condensate and triethanolamine.

[0027] A heat medium channel for temperature control is provided on the outside of the double cone dryer 8. The heat medium flows through the heat medium channel on the outside of the double cone dryer 8 to control the drying temperature inside the double cone dryer 8 to 120℃, so as to prevent the temperature from being too high, which would cause the triethanolamine salt to decompose or deteriorate and affect the stability of the triethanolamine salt product.

[0028] The fixed-bed molecular sieve filter 7 has a heat medium channel on its outer side for temperature control.

[0029] The bag filter 6 has a filtration accuracy of 0.1 to 0.5 microns, which can effectively remove impurities such as tiny particles, colloids, and bacteria from the liquid. It prevents triethanolamine salt from passing through the filter screen of the bag filter 6, but does not hinder dimethyl carbonate from passing through the bag filter 6, thus effectively achieving complete separation of triethanolamine salt and dimethyl carbonate.

[0030] In operation, the lithium difluorooxalate-borate condensate in the lithium difluorooxalate-borate condensate storage tank 1 is transported to the reaction vessel 5 by transfer pump 9, and the triethanolamine in the triethanolamine storage tank 2 is transported to the reaction vessel 5 by transfer pump 10. The lithium difluorooxalate-borate condensate and triethanolamine in the reaction vessel 5 are fully mixed and reacted under the action of the stirring paddle. The optimal reaction temperature in the reaction vessel 5 is controlled at 20°C by the heat medium, so that the triethanolamine can fully deacidify the lithium difluorooxalate-borate condensate. The triethanolamine reacts with the acid in the lithium difluorooxalate-borate condensate to form triethanolamine salt.

[0031] The deacidified lithium difluorooxalate borate condensate and triethanolamine salt enter bag filter 6 for filtration. Dimethyl carbonate passes through the filter screen inside bag filter 6, while triethanolamine salt is blocked by the filter screen inside bag filter 6, thus achieving the separation of dimethyl carbonate and triethanolamine salt.

[0032] The filtered dimethyl carbonate is transported to the fixed-bed molecular sieve filter 7 by the transfer pump 311. The water in the dimethyl carbonate is removed by the fixed-bed molecular sieve filter 7. The dimethyl carbonate filtered by the fixed-bed molecular sieve filter 7 is then transported to the dimethyl carbonate storage tank 3 by the transfer pump 412, thereby realizing the recovery of dimethyl carbonate.

[0033] The triethanolamine salt filtered by bag filter 6 enters the double cone dryer 8 for drying. The internal temperature of the double cone dryer 8 is controlled at 120°C by heat medium. The dried triethanolamine salt enters the triethanolamine salt storage tank 4 for recovery.

[0034] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A device for removing acid and water from lithium difluorooxalate-borate condensate, characterized in that: The reactor includes a reaction vessel (5), the top of which is connected to a lithium difluorooxalate borate condensate storage tank (1) and a triethanolamine storage tank (2), the bottom of which is connected to a bag filter (6), the bottom of which is connected to a fixed bed molecular sieve filter (7), the bottom of which is connected to a dimethyl carbonate storage tank (3), the top of which is connected to a double cone dryer (8), and the bottom of which is connected to a triethanolamine salt storage tank (4).

2. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 1, characterized in that: A transfer pump 1 (9) is provided between the lithium difluorooxalate borate condensate storage tank (1) and the reactor (5), a transfer pump 2 (10) is provided between the triethanolamine storage tank (2) and the reactor (5), a transfer pump 3 (11) is provided between the bag filter (6) and the fixed bed molecular sieve filter (7), and a transfer pump 4 (12) is provided between the fixed bed molecular sieve filter (7) and the dimethyl carbonate storage tank (3).

3. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 1, characterized in that: A heat medium channel for temperature control is provided on the outside of the reactor (5).

4. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 3, characterized in that: The reaction temperature inside the reactor (5) is 20°C.

5. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 1, characterized in that: The double cone dryer (8) has a heat medium channel for temperature control on its outer side.

6. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 5, characterized in that: The reaction temperature inside the double cone dryer (8) is 120°C.

7. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 1, characterized in that: The fixed-bed molecular sieve filter (7) has a heat medium channel for temperature control on its outer side.

8. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 1, characterized in that: The reactor (5) is equipped with a stirring paddle inside, and a motor for controlling the rotation of the stirring paddle is installed on the top of the reactor (5).

9. The device for removing acid and water from lithium difluorooxalate-borate condensate according to claim 1, characterized in that: The filtration accuracy of the bag filter (6) is 0.1 to 0.5 micrometers.

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