Preparation method of metal organic framework composite diaphragm
阅读说明：本技术 金属有机框架复合隔膜的制备方法 (Preparation method of metal organic framework composite diaphragm ) 是由 马源 史新明 刘志刚 董秋春 薛山 刘杲珺 甘珊珊 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种金属有机框架复合隔膜的制备方法,包括以下步骤：(1)将ZrCl-(4)和氨基对苯二甲酸加入到N-N-二甲基甲酰胺中,再加入去离子水,搅拌均匀后在高压反应釜中晶化12-36h得到黄色胶状物,冷却后将得到的黄色胶状物用N’N-二甲基甲酰胺溶液和甲醇溶液分别洗涤后,转移至恒温箱中,干燥后得到多级孔Uio-66-NH-(2),作为多孔隔膜基材；(2)将步骤(1)制得的多级孔Uio-66-NH-(2)置于丙酮溶液中,多级孔Uio-66-NH-(2)与丙酮溶液的重量比为1-40%,搅拌充分形成均匀液,将PVDF加入该均匀液中,PVDF与均匀液的重量比为2-20%,加热搅拌直至PVDF完全溶解得到纺丝原液；(3)将多孔隔膜基材作为接收装置,采用高压静电纺丝技术将纺丝原液直接纺在多孔隔膜基材上,得到金属有机框架复合功能性隔膜。(The invention discloses a preparation method of a metal organic framework composite diaphragm, which comprises the following steps: (1) reacting ZrCl 4 Adding amino terephthalic acid into N-N-dimethylformamide, adding deionized water, stirring uniformly, and placing in a high-pressure reaction kettleCrystallizing for 12-36h to obtain yellow colloid, cooling, washing with N' N-dimethylformamide solution and methanol solution, respectively, transferring into thermostat, and drying to obtain hierarchical pore Uio-66-NH 2 As a porous separator substrate; (2) the multi-stage hole Uio-66-NH prepared in the step (1) 2 Placing in acetone solution, and multi-stage hole Uio-66-NH 2 The weight ratio of the PVDF to the acetone solution is 1-40%, stirring is carried out fully to form uniform liquid, the PVDF is added into the uniform liquid, the weight ratio of the PVDF to the uniform liquid is 2-20%, and heating and stirring are carried out until the PVDF is completely dissolved to obtain spinning stock solution; (3) and (3) taking the porous diaphragm substrate as a receiving device, and directly spinning the spinning stock solution on the porous diaphragm substrate by adopting a high-voltage electrostatic spinning technology to obtain the metal-organic framework composite functional diaphragm.)
1. The preparation method of the metal organic framework composite diaphragm is characterized by comprising the following steps: (1) multi-stage hole UiO-66-NH2The preparation of (1): reacting ZrCl4And amino terephthalic acid are added into N-N-dimethylformamide, and then deionized water and ZrCl are added4The molar mass ratio of the amino terephthalic acid to the volume of the N-N-dimethylformamide is 0.05-0.67 mol/L, the molar mass ratio of the amino terephthalic acid to the volume of the N-N-dimethylformamide is 0.05-0.5 mol/L, the volume ratio of the deionized water to the N-N-dimethylformamide is 0.05-0.67, the mixture is uniformly stirred and then transferred to a high-pressure reaction kettle for crystallization for 12-36h to obtain a yellow jelly, after the reaction kettle is cooled to room temperature, the obtained yellow jelly is respectively washed by N' N-dimethylformamide solution and methanol solution and then transferred to a 100-DEG 150 ℃ constant temperature box, and after drying, a multi-stage hole Uio-66-NH is obtained2As a porous separator substrate; (2) preparing an electrostatic spinning solution: the multi-stage hole Uio-66-NH prepared in the step (1)2Placing the mixture into acetone solution with the mass concentration of 99.5-99.7 percent and multi-stage holes Uio-66-NH2The weight ratio of the PVDF to the acetone solution is 1-40%, stirring is carried out fully to form uniform liquid, the PVDF is added into the uniform liquid, the weight ratio of the PVDF to the uniform liquid is 2-20%, and heating and stirring are carried out until the PVDF is completely dissolved to obtain spinning stock solution; (3) and (3) taking the porous diaphragm substrate as a receiving device, and directly spinning the spinning solution obtained in the step (2) on the porous diaphragm substrate by adopting a high-voltage electrostatic spinning technology to obtain the metal organic framework composite functional diaphragm.
2. The method for preparing a metal organic framework composite separator according to claim 1, wherein: in the step (1), the crystallization temperature in the high-pressure reaction kettle is 120-200 ℃.
3. The method for preparing a metal organic framework composite separator according to claim 1, wherein: in the step (1), a high-pressure reaction kettle for crystallization reaction is provided with a polytetrafluoroethylene lining.
4. The method for preparing a metal organic framework composite separator according to claim 1, wherein: in step (1), the yellow gum was washed three times with each of N' N-dimethylformamide and methanol solutions.
5. The method for preparing a metal organic framework composite separator according to claim 1, wherein: in the step (1), the drying time is 6-12 h.
6. The method for preparing a metal organic framework composite separator according to claim 1, wherein: in the step (2), the multi-stage holes Uio-66-NH2The weight ratio of the PVDF and the acetone solution is 5-20%, and the weight ratio of the PVDF and the homogeneous liquid is 5-10%.
7. The method for preparing a metal organic framework composite separator according to claim 1, wherein: the viscosity of the spinning solution obtained in the step (2) is 2000-9000 mPa.s.
8. The method for preparing a metal organic framework composite separator according to claim 1, wherein: in the step (3), the spinning voltage of the high-voltage electrostatic spinning is 10KV-40KV, the spinning speed is 1-5ml/h, and the distance between the spinning nozzle and the porous diaphragm base material is 5-20 cm.
9. The method of preparing a metal organic framework composite separator according to claim 8, wherein: the distance between the spinning nozzle and the base film is 10-20 cm.
Technical Field
The invention relates to a preparation method of a metal organic framework composite diaphragm, and belongs to the technical field of lithium battery diaphragm production.
Background
With the rapid development of lithium battery technology, the development of lithium ion batteries with higher energy density is imperative. The lithium ion battery with high energy density requires higher ion transmission rate, and the lithium ion migration rate and the ion conductivity of the lithium battery diaphragm directly influence the electrochemical performance and the safety performance of the lithium ion battery. However, the lithium ion migration rate and the ionic conductivity of the current lithium battery diaphragm are not ideal. Therefore, the diaphragm with high ion migration rate and ion conductivity is urgently needed to be invented, and meanwhile, the thermal stability and the corrosion resistance are met, and the electrolyte wettability is good.
Disclosure of Invention
The invention aims to provide a preparation method of a metal organic framework composite diaphragm, which is used for improving the ion migration rate and the ion conductivity of a lithium ion battery diaphragm.
The invention adoptsThe technical scheme is as follows: the preparation method of the metal organic framework composite diaphragm comprises the following steps: (1) multi-stage hole UiO-66-NH2The preparation of (1): reacting ZrCl4And amino terephthalic acid are added into N-N-dimethylformamide, and then deionized water and ZrCl are added4The molar mass ratio of the amino terephthalic acid to the volume of the N-N-dimethylformamide is 0.05-0.67 mol/L, the molar mass ratio of the amino terephthalic acid to the volume of the N-N-dimethylformamide is 0.05-0.5 mol/L, the volume ratio of the deionized water to the N-N-dimethylformamide is 0.05-0.67, the mixture is uniformly stirred and then transferred to a high-pressure reaction kettle for crystallization for 12-36h to obtain a yellow jelly, after the reaction kettle is cooled to room temperature, the obtained yellow jelly is respectively washed by N' N-dimethylformamide solution and methanol solution and then transferred to a 100-DEG 150 ℃ constant temperature box, and after drying, a multi-stage hole Uio-66-NH is obtained2As a porous separator substrate; (2) preparing an electrostatic spinning solution: the multi-stage hole Uio-66-NH prepared in the step (1)2Placing the mixture into acetone solution with the mass concentration of 99.5-99.7 percent and multi-stage holes Uio-66-NH2The weight ratio of the PVDF to the acetone solution is 1-40%, stirring is carried out fully to form uniform liquid, the PVDF is added into the uniform liquid, the weight ratio of the PVDF to the uniform liquid is 2-20%, and heating and stirring are carried out until the PVDF is completely dissolved to obtain spinning stock solution; (3) and (3) taking the porous diaphragm substrate as a receiving device, and directly spinning the spinning solution obtained in the step (2) on the porous diaphragm substrate by adopting a high-voltage electrostatic spinning technology to obtain the metal organic framework composite functional diaphragm.
In the step (1), a high-pressure reaction kettle for crystallization reaction is provided with a polytetrafluoroethylene lining.
In step (1), the yellow gum was washed three times with each of N' N-dimethylformamide and methanol solutions.
In the step (1), the drying time is 6-12 h.
In the step (2), the multi-stage holes Uio-66-NH2The weight ratio of the PVDF and the acetone solution is 5-20%, and the weight ratio of the PVDF and the homogeneous liquid is 5-10%.
The viscosity of the spinning solution obtained in the step (2) is 2000-9000 mPa.s.
In the step (3), the spinning voltage of the high-voltage electrostatic spinning is 10KV-40KV, the spinning speed is 1-5ml/h, and the distance between the spinning nozzle and the porous diaphragm base material is 5-20 cm.
The distance between the spinning nozzle and the base film is 10-20 cm.
The invention has the beneficial effects that: the invention firstly prepares hierarchical pore UiO-66-NH by crystallization, washing and drying2I.e. a metal organic framework material MOF, and then subjecting the hierarchical pore UiO-66-NH2Mixing the obtained product with acetone solution and PVDF to form spinning solution, and finally spinning the spinning solution on a porous diaphragm substrate to obtain the diaphragm with the metal organic frame layer. Because the nano-channel and the particle gap channel with negative charges in the metal organic framework material MOF can limit the migration of anions, the migration number of the prepared diaphragm lithium ions is improved, so that the migration rate and the ionic conductivity of the lithium ions are improved, and the rate performance of the battery is improved; due to UiO-66-NH2Has the characteristics of high specific surface area, excellent thermal stability and chemical stability, and is prepared by mixing multi-stage pores UiO-66-NH2The composite material is mixed with acetone solution and PVDF and spun on a porous diaphragm base material, so that the thermal stability and the corrosion resistance of the diaphragm are improved, meanwhile, the specific surface area of the diaphragm is increased, and the electrolyte wettability of the lithium ion battery is improved.
Detailed Description
The present invention will be described in detail with reference to specific examples. The porous separator substrate used in the following examples was a separator substrate made of a polymer material according to the related art.
Example 1:
the preparation method of the metal organic framework composite diaphragm adopts the following steps:
(1) multi-stage hole UiO-66-NH2The preparation of (1): adding 5mmol of ZrCl45 mmol-amino terephthalic acid is added into 30ml of N-N-dimethylformamide, then 5ml of deionized water is added, after uniform stirring, the mixture is transferred into a high-pressure reaction kettle with a polytetrafluoroethylene lining and crystallized for 24 hours at 120 ℃. After the reaction kettle is cooled to room temperature, the obtained yellow jelly is washed by N' N-dimethylformamide solution and methanol solution for three times respectively, then the yellow jelly is transferred to a thermostat at 100 ℃, and is dried for 12 DEGh。
(2) Preparing an electrostatic spinning solution: the multi-stage hole Uio-66-NH prepared in the step (1)2Placing the mixture into acetone solution with the mass concentration of 99.5-99.7 percent and multi-stage holes Uio-66-NH2And the weight ratio of the PVDF to the acetone solution is 20%, stirring the mixture fully to form a uniform solution, adding the PVDF into the uniform solution, wherein the weight ratio of the PVDF to the uniform solution is 10%, heating and stirring the mixture until the PVDF is completely dissolved to obtain a spinning stock solution, and the viscosity of the spinning stock solution is 3000 mPa.s.
(3) And (3) taking the porous diaphragm substrate as a receiving device, and directly spinning the spinning solution obtained in the step (2) on the porous diaphragm substrate by adopting a high-voltage electrostatic spinning technology to obtain the metal organic framework composite functional diaphragm. Wherein the spinning voltage in the high electrostatic spinning technology is 10KV, the spinning speed is 2ml/h, and the distance between the spinning nozzle and the porous base membrane is 20 cm.
The ion migration rate of the metal organic framework composite functional diaphragm is evaluated by an electrochemical method, the ion migration number is 0.45 through calculation by a classical Bruce-Vincent method, and the conductivity is 0.92ms/cm through impedance test. Compared with the diaphragm in the prior art, the ion transport number is 0.2-0.35, the conductivity is 0.5-0.8 ms/cm, and the ion transport number and the conductivity are both obviously improved.
The wettability of the electrolyte is an important parameter of the diaphragm, and the wettability of the electrolyte is characterized by an electrolyte contact angle in the embodiment. The contact angle of the diaphragm in the prior art is generally 30-60 degrees, the contact angle of the diaphragm in the embodiment is 12 degrees, and the diaphragm has better electrolyte wettability compared with the diaphragm in the embodiment in the prior art.
Example 2
The preparation method of the metal organic framework composite diaphragm adopts the following steps:
(1) multi-stage hole UiO-66-NH2The preparation of (1): adding 20mmol of ZrCl415mmol of amino terephthalic acid is added into 100ml of N-N-dimethylformamide, then 20ml of deionized water is added, after uniform stirring, the mixture is transferred into a high-pressure reaction kettle with a polytetrafluoroethylene lining and crystallized for 36 hours at 120 ℃. After the reaction kettle is cooled to room temperature, dissolving the obtained yellow jelly by using N' N-dimethylformamideAfter washing the solution and the methanol solution three times each, the solution was transferred to a 100 ℃ incubator and dried for 6 hours.
(2) Preparing an electrostatic spinning solution: the multi-stage hole Uio-66-NH prepared in the step (1)2Placing the mixture into acetone solution with the mass concentration of 99.5-99.7 percent and multi-stage holes Uio-66-NH2And the weight ratio of the PVDF to the acetone solution is 30%, stirring the mixture fully to form a uniform solution, adding the PVDF into the uniform solution, wherein the weight ratio of the PVDF to the uniform solution is 10%, heating and stirring the mixture until the PVDF is completely dissolved to obtain a spinning stock solution, and the viscosity of the spinning stock solution is 9000 mPa.s.
(3) And (3) taking the porous base material as a receiving device, and directly spinning the spinning solution obtained in the step (2) on the base material by adopting a high-voltage electrostatic spinning technology to obtain the metal-organic framework composite functional diaphragm. Wherein the spinning voltage of the high-voltage electrostatic spinning technology is 40KV, the spinning speed is 1ml/h, and the distance between the spinning nozzle and the porous base membrane is 5 cm.
The ion migration rate of the metal organic framework composite functional diaphragm is evaluated by an electrochemical method, the ion migration number is 0.48 through calculation by a classical Bruce-Vincent method, and the conductivity is 0.97ms/cm through impedance test. Compared with the prior art, the ion migration number and the conductivity are obviously improved.
The wettability of the electrolyte is an important parameter of the diaphragm, and the wettability of the electrolyte is characterized by an electrolyte contact angle in the embodiment. The contact angle of the diaphragm in the prior art is generally 30-60 degrees, the contact angle of the diaphragm in the embodiment is 7 degrees, and the diaphragm has better electrolyte wettability compared with the diaphragm in the embodiment in the prior art.
Example 3
The preparation method of the metal organic framework composite diaphragm adopts the following steps:
(1) multi-stage hole UiO-66-NH2The preparation of (1): adding 20mmol of ZrCl415mmol of amino terephthalic acid is added into 100ml of N-N-dimethylformamide, then 20ml of deionized water is added, after uniform stirring, the mixture is transferred into a high-pressure reaction kettle with a polytetrafluoroethylene lining and crystallized for 36 hours at 120 ℃. After the reaction kettle is cooled to room temperature, the obtained yellow jelly is dissolved in N' N-dimethylformamide solution and methanolAfter washing the solution three times each, it was transferred to a 100 ℃ incubator and dried for 6 hours.
(2) Preparing an electrostatic spinning solution: the multi-stage hole Uio-66-NH prepared in the step (1)2Placing the mixture into acetone solution with the mass concentration of 99.5-99.7 percent and multi-stage holes Uio-66-NH2The weight ratio of the PVDF to the acetone solution is 40%, the PVDF and the uniform solution are fully stirred to form uniform solution, the PVDF is added into the uniform solution, the weight ratio of the PVDF to the uniform solution is 20%, the PVDF is heated and stirred until being completely dissolved to obtain spinning solution, and the viscosity of the spinning solution is 9000 mPa.s.
(3) And (3) taking the porous base material as a receiving device, and directly spinning the spinning solution obtained in the step (2) on the base material by adopting a high-voltage electrostatic spinning technology to obtain the metal-organic framework composite functional diaphragm. Wherein the spinning voltage of the high-voltage electrostatic spinning technology is 40KV, the spinning speed is 1ml/h, and the distance between the spinning nozzle and the porous base membrane is 5 cm.
The ion migration rate of the metal organic framework composite functional diaphragm is evaluated by an electrochemical method, the ion migration number is 0.46 through calculation by a classical Bruce-Vincent method, and the conductivity is 0.93ms/cm through impedance test.
The wettability of the electrolyte is an important parameter of the diaphragm, and the wettability of the electrolyte is characterized by an electrolyte contact angle in the embodiment. The contact angle of the diaphragm in the prior art is generally 30-60 degrees, the contact angle of the diaphragm in the embodiment is 10 degrees, and the diaphragm has better electrolyte wettability compared with the diaphragm in the embodiment in the prior art.
Example 4
The preparation method of the metal organic framework composite diaphragm adopts the following steps:
(1) multi-stage hole UiO-66-NH2The preparation of (1): adding 20mmol of ZrCl415mmol of amino terephthalic acid is added into 400ml of N-N-dimethylformamide, then 20ml of deionized water is added, after uniform stirring, the mixture is transferred into a high-pressure reaction kettle with a polytetrafluoroethylene lining and crystallized for 36 hours at 200 ℃. After the reaction kettle is cooled to room temperature, the obtained yellow jelly is washed three times by N' N-dimethylformamide solution and methanol solution respectively, and then is transferred to a thermostat at 150 ℃ and dried for 12 hours.
(2) Preparing an electrostatic spinning solution: the multi-stage hole Uio-66-NH prepared in the step (1)2Placing the mixture into acetone solution with the mass concentration of 99.5-99.7 percent and multi-stage holes Uio-66-NH2And the weight ratio of the PVDF to the acetone solution is 5%, stirring the mixture fully to form a uniform solution, adding the PVDF into the uniform solution, wherein the weight ratio of the PVDF to the uniform solution is 5%, heating and stirring the mixture until the PVDF is completely dissolved to obtain a spinning stock solution, and the viscosity of the spinning stock solution is 3000 mPa.s.
(3) And (3) taking the porous base material as a receiving device, and directly spinning the spinning solution obtained in the step (2) on the base material by adopting a high-voltage electrostatic spinning technology to obtain the metal-organic framework composite functional diaphragm. Wherein the spinning voltage of the high-voltage electrostatic spinning technology is 40KV, the spinning speed is 3ml/h, and the distance between the spinning nozzle and the porous base membrane is 10 cm.
The ion migration rate of the metal organic framework composite functional diaphragm is evaluated by an electrochemical method, the ion migration number is 0.38 through calculation by a classical Bruce-Vincent method, and the conductivity is 0.85ms/cm through impedance test.
The wettability of the electrolyte is an important parameter of the diaphragm, and the wettability of the electrolyte is characterized by an electrolyte contact angle in the embodiment. The contact angle of the diaphragm in the prior art is generally 30-60 degrees, the contact angle of the diaphragm in the embodiment is 15 degrees, and the diaphragm has better electrolyte wettability compared with the diaphragm in the embodiment in the prior art.
Example 5
The preparation method of the metal organic framework composite diaphragm adopts the following steps:
(1) multi-stage hole UiO-66-NH2The preparation of (1): adding 20mmol of ZrCl415mmol of amino terephthalic acid is added into 30ml of N-N-dimethylformamide, then 20ml of deionized water is added, after uniform stirring, the mixture is transferred into a high-pressure reaction kettle with a polytetrafluoroethylene lining and crystallized for 12 hours at 150 ℃. After the reaction kettle is cooled to room temperature, the obtained yellow jelly is washed three times by N' N-dimethylformamide solution and methanol solution respectively, and then is transferred to a thermostat at 150 ℃ and dried for 10 hours.
(2) Preparing an electrostatic spinning solution: the multi-stage prepared in the step (1)Opening Uio-66-NH2Placing the mixture into acetone solution with the mass concentration of 99.5-99.7 percent and multi-stage holes Uio-66-NH2The weight ratio of the PVDF to the acetone solution is 1%, the PVDF and the uniform solution are fully stirred to form uniform solution, the PVDF is added into the uniform solution, the weight ratio of the PVDF to the uniform solution is 2%, the PVDF is heated and stirred until being completely dissolved to obtain spinning solution, and the viscosity of the spinning solution is 2000 mPa.s.
(3) And (3) taking the porous base material as a receiving device, and directly spinning the spinning solution obtained in the step (2) on the base material by adopting a high-voltage electrostatic spinning technology to obtain the metal-organic framework composite functional diaphragm. Wherein the spinning voltage of the high-voltage electrostatic spinning technology is 40KV, the spinning speed is 3ml/h, and the distance between the spinning nozzle and the porous base membrane is 10 cm.
The ion migration rate of the metal organic framework composite functional diaphragm is evaluated by an electrochemical method, the ion migration number is calculated to be 0.36 by a classical Bruce-Vincent method, and the conductivity is obtained to be 0.82ms/cm by an impedance test.
The wettability of the electrolyte is an important parameter of the diaphragm, and the wettability of the electrolyte is characterized by an electrolyte contact angle in the embodiment. The contact angle of the diaphragm in the prior art is generally 30-60 degrees, the contact angle of the diaphragm in the embodiment is 20 degrees, and the diaphragm has better electrolyte wettability compared with the diaphragm in the embodiment in the prior art.
As can be shown by the above examples and experimental data, the hierarchical pore UiO-66-NH2The metal organic framework composite diaphragm prepared by mixing and spinning the porous diaphragm substrate with acetone solution and PVDF can improve the ion migration rate, the ion conductivity and the conductivity of the lithium ion battery and the wettability of electrolyte.
The above embodiments are some preferred embodiments of the present invention, and in other embodiments of the present invention, in step (1), ZrCl is used4The ratio of the molar mass of the N-dimethylformamide to the volume of the N-N-dimethylformamide is 0.05 to 0.67mol/L, the ratio of the molar mass of the aminoterephthalic acid to the volume of the N-N-dimethylformamide is 0.05 to 0.5 mol/L, and the ratio of the deionized water to the volume of the N-N-dimethylformamide is 0.05 to 0.67; in the step (2), the multi-stage holes Uio-66-NH2The weight ratio of the PVDF to the acetone solution is preferably 5-20%, PVDF and homoThe weight ratio of the uniform solution is preferably 5-10%, and the viscosity of the finally obtained spinning solution is preferably 2000-9000 mPa.s; in the step (3), the spinning voltage of the high-voltage electrostatic spinning is preferably 10KV-40KV, the spinning speed is preferably 1-5ml/h, and the distance between the spinning nozzle and the porous diaphragm base material is preferably 10-20 cm.
Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the above-described embodiments. The scope of the invention defined by the appended claims encompasses all equivalent substitutions and modifications.