A self-healing polyurethane-based stretchable fluid concentrator

Abstract

This invention discloses a stretchable current collector based on self-healing polyurethane, characterized in that the stretchable current collector is formed by in-situ composite of a substrate layer and a conductive layer. The substrate layer is a self-healing polyurethane film with a wrinkled surface, synthesized from a linear polyurethane precursor obtained by reacting diisocyanate with polyether diol and alkyl diol / amine, and a multi-hydroxyl crosslinking agent containing dynamic chemical bonds. The conductive layer is composed of the linear polyurethane precursor of the substrate material, an anionic linear polyurethane precursor synthesized by reacting diisocyanate with polyether diol and sulfonic acid diol / amine, a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a one-dimensional conductive material. The stretchable current collector prepared by this invention has an initial sheet resistance of less than 200 Ωsq. −1 It has an elongation at break greater than 550%, and its electrical conductivity remains excellent even after undergoing extremely large tensile strain.

Description

Technical Field

[0001] This invention belongs to the field of new energy materials technology, specifically relating to a stretchable current collector based on self-healing polyurethane. Background Technology

[0002] With the rapid development of wearable electronic devices, electronic skin, and implantable medical devices, the demand for flexible energy storage devices is increasing. Currently, the development of electrochemical energy storage devices suitable for flexible electronic devices is a major technological bottleneck. These devices should possess high deformability and ideal electrochemical performance, thus realizing flexible electrochemical energy storage devices. Among various deformation states such as bending, torsion, and tension, large-scale tensile deformation is considered the most damaging to the device structure. Therefore, constructing stretchable electrochemical energy storage devices would meet the application scenarios of most flexible electronic devices. The stretchable current collector is one of the most critical components of electrochemical energy storage devices. Its main function is to collect the current generated by the electrode active material to form a larger current output. How to achieve high stretchability while maintaining high conductivity is a problem that researchers are committed to solving.

[0003] Currently, there are some studies on stretchable current collectors. Researchers have attempted to prepare stretchable current collectors using various intrinsically elastic materials, such as silicone rubber and fluororubber. The typical approach involves using an elastic material as a substrate, directly coating its surface with a conductive paste and an electrochemically active material, and often placing an adhesive layer between the substrate and the conductive layer. However, due to the mismatch in stretchability between the substrate and the surface material, cracking of the surface conductive layer often occurs during stretching, resulting in a sharp increase in resistance and significantly affecting device performance. Therefore, there is an urgent need in this field to find a stretchable current collector that combines excellent stretchability and superior conductivity, with a strong chemical bond between the conductive layer and the substrate material. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the main objective of the present invention is to provide a stretchable current collector based on self-healing polyurethane.

[0005] To achieve the above objectives, according to one aspect of the present invention, a stretchable current collector based on self-healing polyurethane is provided, characterized in that the current collector has a two-layer structure composed of a base layer and a conductive layer in situ, wherein the base layer is a self-healing polyurethane film with a wrinkled surface, and the conductive layer is an anionic self-healing polyurethane with a network structure encapsulating a one-dimensional conductive material. The stretchable current collector based on self-healing polyurethane is prepared by the following main steps: (1) reacting diisocyanate with polyether diol and alkyl diol / amine in a molar ratio of 1:2 to synthesize linear polyurethane precursor A; (2) reacting diisocyanate with polyether diol and sulfonic acid diol / amine in a molar ratio of 1:2 to synthesize anionic linear polyurethane precursor B; (3) reacting A with a multi-hydroxy crosslinking agent containing dynamic chemical bonds to synthesize self-healing polyurethane, and preparing a self-healing polyurethane film by solution casting; (4) fully swelling the self-healing polyurethane film with an organic solvent, and then coating the swollen self-healing polyurethane film with a conductive slurry made by mixing linear polyurethane precursor A, anionic linear polyurethane precursor B, multi-hydroxy crosslinking agent containing dynamic chemical bonds and one-dimensional conductive material in a certain proportion; (5) finally drying the coated film to obtain the stretchable current collector based on self-healing polyurethane.

[0006] Furthermore, the initial sheet resistance of the stretchable current collector based on self-healing polyurethane is less than 200 Ωsq. −1 The elongation at break is greater than 550%, and the sheet resistance of the stretchable current collector after being subjected to a tensile strain of 550% and returning to its initial length does not exceed 10 times the initial sheet resistance.

[0007] Furthermore, the diisocyanate in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of isophorone diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and toluene diisocyanate.

[0008] Furthermore, the polyether diol in the method for preparing the stretchable current collector based on self-healing polyurethane is one or more of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran.

[0009] Furthermore, in the method for preparing the stretchable current collector based on self-healing polyurethane, the alkyl diol / amine is one or more of ethylene glycol, propylene glycol, 1,4-butanediol, ethylenediamine, and propylenediamine.

[0010] Furthermore, in the method for preparing the stretchable current collector based on self-healing polyurethane, the sulfonic acid diol / amine is one or more of sodium ethylenediamine ethanesulfonate and sodium N,N-di(2-hydroxyethyl)-2-aminoethanesulfonate.

[0011] Furthermore, the multi-hydroxy crosslinking agent containing dynamic chemical bonds in the preparation method of the stretchable current collector based on self-healing polyurethane is prepared by the following main steps: (1) reacting hydroxy aldehyde with diamine in a molar ratio of 2:1 to synthesize compound A containing imine group and two terminal hydroxyl groups; (2) reacting A with diisocyanate trimer in a molar ratio of 3:1 to generate multi-hydroxy crosslinking agent containing dynamic chemical bonds; wherein, the hydroxy aldehyde is one of 3-hydroxypropanal, p-hydroxybenzaldehyde, and o-hydroxybenzaldehyde; the diamine is one of ethylenediamine, hexamethylenediamine, and 4,4'-diaminodiphenylmethane; and the diisocyanate trimer is one of isophorone diisocyanate trimer and hexamethylene diisocyanate trimer.

[0012] Furthermore, the one-dimensional conductive material in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of carbon nanotubes, polythiophene nanowires, silver nanowires, copper nanowires, and gold nanowires.

[0013] Furthermore, the organic solvent in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and acetone.

[0014] Furthermore, in the method for preparing the stretchable current collector based on self-healing polyurethane, the ratio of linear polyurethane precursor A to anionic linear polyurethane precursor B in the conductive slurry is one of 0.25 to 4; the ratio of polyurethane precursor to polyhydroxy crosslinking agent containing dynamic chemical bonds is one of 0.6 to 1.5; the ratio of polyurethane precursor to one-dimensional conductive material is one of 0.5 to 2; and the drying temperature is 40 to 120°C.

[0015] Compared to conventional stretchable current collectors or stretchable electrodes, the stretchable current collector based on self-healing polyurethane of this invention is connected between the conductive layer and the substrate material through reversible dynamic chemical bonds, preventing relative slippage. Furthermore, the one-dimensional conductive material in the conductive layer is encapsulated by the self-healing polyurethane, which avoids the generation and accumulation of cracks in the conductive network. Therefore, the stretchable current collector based on self-healing polyurethane of this invention maintains excellent conductivity even after undergoing ultra-large tensile strain. Attached Figure Description

[0016] Figure 1 The image shows a 2000x magnified scanning electron microscope image of the side surface of the stretchable current collector based on self-healing polyurethane prepared in Example 7. 1 represents the conductive layer, and 2 represents the substrate layer.

[0017] Figure 2The image is a 1000x magnified scanning electron microscope image of the stretchable current collector surface based on self-healing polyurethane prepared in Example 7.

[0018] Figure 3 The image shown is a scanning electron microscope image magnified 100,000 times of the stretchable current collector conductive layer based on self-healing polyurethane prepared in Example 7. 3 represents silver nanowires, and 4 represents the polyurethane coating layer. Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0020] Example 1

[0021] This embodiment provides a stretchable current collector based on self-healing polyurethane, characterized in that the current collector has a two-layer structure composed of a base layer and a conductive layer in situ. The base layer is a self-healing polyurethane film with a wrinkled surface, and the conductive layer is an anionic self-healing polyurethane with a network structure encapsulating a one-dimensional conductive material.

[0022] The specific steps of its preparation method are as follows.

[0023] 1. A linear polyurethane precursor A was synthesized by reacting isophorone diisocyanate with polyethylene glycol and ethylene glycol in a molar ratio of 3:4:2.

[0024] 2. An anionic linear polyurethane precursor B was synthesized by reacting hexamethylene diisocyanate with polypropylene glycol and sodium hexamethylenediamine ethanesulfonate in a molar ratio of 3:4:2.

[0025] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0026] The polyhydroxy crosslinking agent was prepared by the following method: (1) 3-hydroxypropionaldehyde was reacted with 4,4'-diaminodiphenylmethane in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) A was reacted with isophorone diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0027] 4. Use N,N-dimethylformamide organic solvent to fully swell the self-healing polyurethane film, and then coat the swollen self-healing polyurethane film with a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds and carbon nanotubes in a ratio of 3:12:20:24.

[0028] 5. Finally, the coated film is dried at 40 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0029] Example 2

[0030] 1. A linear polyurethane precursor A was synthesized by reacting diphenylmethane diisocyanate with polypropylene glycol and propylene glycol in a molar ratio of 3:4:2.

[0031] 2. An anionic linear polyurethane precursor B was synthesized by reacting toluene diisocyanate with polytetrahydrofuran and sodium N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonate in a molar ratio of 3:4:2.

[0032] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0033] The polyhydroxy crosslinking agent is prepared by the following method: (1) reacting p-hydroxybenzaldehyde with ethylenediamine in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with isophorone diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0034] 4. Use N,N-dimethylacetamide organic solvent to fully swell the self-healing polyurethane film, and then coat the swollen self-healing polyurethane film with a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds and polythiophene nanowires in a ratio of 24:6:20:15.

[0035] 5. Finally, the coated film is dried at 120 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0036] Example 3

[0037] 1. A linear polyurethane precursor A was synthesized by reacting diphenyltoluene diisocyanate with polytetrahydrofuran and 1,4-butanediol in a molar ratio of 3:4:2.

[0038] 2. An anionic linear polyurethane precursor B was synthesized by reacting toluene diisocyanate with polytetrahydrofuran and sodium N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonate in a molar ratio of 3:4:2.

[0039] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0040] The polyhydroxy crosslinking agent was prepared by the following method: (1) reacting o-hydroxybenzaldehyde with ethylenediamine in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with hexamethylene diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0041] 4. The self-healing polyurethane film is fully swollen using dimethyl sulfoxide organic solvent, and then a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds and silver nanowires in a ratio of 2:1:3:3 is coated onto the swollen self-healing polyurethane film.

[0042] 5. Finally, the coated film is dried at 80 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0043] Example 4

[0044] 1. A linear polyurethane precursor A was synthesized by reacting toluene diisocyanate with polytetrahydrofuran and ethylene glycol in a molar ratio of 3:4:2.

[0045] 2. An anionic linear polyurethane precursor B was synthesized by reacting toluene diisocyanate with polytetrahydrofuran and sodium N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonate in a molar ratio of 3:4:2.

[0046] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0047] The polyhydroxy crosslinking agent was prepared by the following method: (1) reacting o-hydroxybenzaldehyde with hexamethylenediamine in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with isophorone diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0048] 4. Fully swell the self-healing polyurethane film with acetone, and then coat the swollen self-healing polyurethane film with a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds and copper nanowires in a ratio of 2:1:2:2.

[0049] 5. Finally, the coated film is dried at 80 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0050] Example 5

[0051] 1. A linear polyurethane precursor A was synthesized by reacting isophorone diisocyanate with polypropylene glycol and ethylene glycol in a molar ratio of 3:4:2.

[0052] 2. An anionic linear polyurethane precursor B was synthesized by reacting hexamethylene diisocyanate with polyethylene glycol and sodium hexamethylenediamine ethanesulfonate in a molar ratio of 3:4:2.

[0053] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0054] The polyhydroxy crosslinking agent is prepared by the following method: (1) reacting p-hydroxybenzaldehyde with hexamethylenediamine in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with isophorone diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0055] 4. Use N,N-dimethylformamide organic solvent to fully swell the self-healing polyurethane film, and then coat the swollen self-healing polyurethane film with a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds and carbon nanotubes in a ratio of 3:1:5:6.

[0056] 5. Finally, the coated film is dried at 80 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0057] Example 6

[0058] 1. A linear polyurethane precursor A was synthesized by reacting diphenylmethane diisocyanate with polyethylene glycol and propylene glycol in a molar ratio of 3:4:2.

[0059] 2. An anionic linear polyurethane precursor B was synthesized by reacting toluene diisocyanate with polytetrahydrofuran and sodium N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonate in a molar ratio of 3:4:2.

[0060] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0061] The polyhydroxy crosslinking agent is prepared by the following method: (1) reacting p-hydroxybenzaldehyde with ethylenediamine in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with isophorone diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0062] 4. The self-healing polyurethane film is fully swollen using N,N-dimethylacetamide organic solvent. Then, a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds, and silver nanowires in a ratio of 3:3:8:6 is coated onto the swollen self-healing polyurethane film.

[0063] 5. Finally, the coated film is dried at 60 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0064] Example 7

[0065] 1. A linear polyurethane precursor A was synthesized by reacting isophorone diisocyanate with polyethylene glycol and 1,4-butanediol in a molar ratio of 3:4:2.

[0066] 2. Anionic linear polyurethane precursor B was synthesized by reacting isophorone diisocyanate with polyethylene glycol and sodium N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonate in a molar ratio of 3:4:2.

[0067] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0068] The polyhydroxy crosslinking agent is prepared by the following method: (1) reacting p-hydroxybenzaldehyde with 4,4'-diaminodiphenylmethane in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with hexamethylene diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0069] 4. The self-healing polyurethane film is fully swollen using N,N-dimethylacetamide organic solvent. Then, a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds, and silver nanowires in a ratio of 9:9:10:36 is coated onto the swollen self-healing polyurethane film.

[0070] 5. Finally, the coated film is dried at 105 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0071] Example 8

[0072] 1. A linear polyurethane precursor A was synthesized by reacting diphenylmethane diisocyanate with polypropylene glycol and ethylene glycol in a molar ratio of 3:4:2.

[0073] 2. An anionic linear polyurethane precursor B was synthesized by reacting toluene diisocyanate with polytetrahydrofuran and sodium N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonate in a molar ratio of 3:4:2.

[0074] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0075] The polyhydroxy crosslinking agent is prepared by the following method: (1) reacting p-hydroxybenzaldehyde with hexamethylenediamine in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with isophorone diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0076] 4. Use acetone to fully swell the self-healing polyurethane film, and then coat the swollen self-healing polyurethane film with a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds and gold nanowires in a ratio of 5:5:7:6.

[0077] 5. Finally, the coated film is dried at 75 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0078] Example 9

[0079] 1. A linear polyurethane precursor A was synthesized by reacting hexamethylene diisocyanate with polypropylene glycol and ethylene glycol in a molar ratio of 3:4:2.

[0080] 2. An anionic linear polyurethane precursor B was synthesized by reacting hexamethylene diisocyanate with polyethylene glycol and sodium N,N-di(2-hydroxyethyl)-2-aminoethanesulfonate in a molar ratio of 3:4:2.

[0081] 3. A self-healing polyurethane was synthesized by reacting A with a multi-hydroxyl crosslinking agent containing dynamic chemical bonds, and a self-healing polyurethane film was prepared by solution casting.

[0082] The polyhydroxy crosslinking agent is prepared by the following method: (1) reacting p-hydroxybenzaldehyde with hexamethylenediamine in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (2) reacting A with isophorone diisocyanate trimer in a molar ratio of 3:1 to generate a polyhydroxy crosslinking agent containing dynamic chemical bonds.

[0083] 4. The self-healing polyurethane film is fully swollen using dimethyl sulfoxide, and then a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds, and gold nanowires in a ratio of 7:3:8:6 is coated onto the swollen self-healing polyurethane film.

[0084] 5. Finally, the coated film is dried at 60 degrees Celsius. After drying, a stretchable current collector based on self-healing polyurethane is obtained.

[0085] Comparative Example 1

[0086] Compared with Example 7, the first three preparation processes are the same. In the fourth coating process, the conductive paste is first coated on the mold and dried, then the polyurethane matrix is ​​poured in and dried and cured. Finally, the matrix and the conductive paste are peeled off together to obtain a stretchable current collector with no wrinkles on the surface.

[0087] Comparative Example 2

[0088] The preparation process is the same as in Example 7, but trimethylolpropane is chosen as the crosslinking agent.

[0089] Table 1. Properties of the stretchable current collectors prepared in each embodiment and comparative example

[0090]

[0091] As can be seen from Table 1, in Examples 1 to 9, the elongation at break of the stretchable current collector gradually decreases as the proportion of crosslinking agent increases; the lowest sheet resistance can be obtained by using silver nanowires; and the sheet resistance decreases as the proportion of conductive paste increases.

[0092] Comparing Example 7 with Comparative Example 1, it can be found that wrinkles on the current collector surface can result in lower sheet resistance because the conductive network is denser when there are wrinkles.

[0093] Comparing Example 7 with Comparative Example 2 reveals that the resistance of the polyurethane matrix, which lacks self-healing properties, increases sharply after undergoing significant deformation and recovery.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A stretchable current collector based on self-healing polyurethane, characterized in that, The current collector has a two-layer structure composed of a base layer and a conductive layer in situ. The base layer is a self-healing polyurethane film with a wrinkled surface, and the conductive layer is an anionic self-healing polyurethane with a network structure encapsulating a one-dimensional conductive material. The stretchable current collector based on self-healing polyurethane is prepared by a method with the following main steps: (1) A linear polyurethane precursor A was synthesized by reacting diisocyanate with polyether diol and alkyl diol / amine in a molar ratio of 3:4:2; (2) Anionic linear polyurethane precursor B was synthesized by reacting diisocyanate with polyether diol and sulfonic acid diol / amine in a molar ratio of 3:4:2; (3) The precursor A is reacted with a multi-hydroxy crosslinking agent containing dynamic chemical bonds to synthesize a self-healing polyurethane, and a self-healing polyurethane film is prepared by solution casting. The multi-hydroxy crosslinking agent containing dynamic chemical bonds is prepared by the following main steps: (a) hydroxy aldehyde and diamine are reacted in a molar ratio of 2:1 to synthesize compound A containing an imine group and two terminal hydroxyl groups; (b) compound A is reacted with diisocyanate trimer in a molar ratio of 3:1 to generate a multi-hydroxy crosslinking agent containing dynamic chemical bonds. The hydroxy aldehyde is one of 3-hydroxypropanal, p-hydroxybenzaldehyde, and o-hydroxybenzaldehyde; the diamine is one of ethylenediamine, hexamethylenediamine, and 4,4'-diaminodiphenylmethane; and the diisocyanate trimer is one of isophorone diisocyanate trimer and hexamethylene diisocyanate trimer. (4) Use an organic solvent to fully swell the self-healing polyurethane film, and then coat the swollen self-healing polyurethane film with a conductive paste made of linear polyurethane precursor A, anionic linear polyurethane precursor B, a multi-hydroxy crosslinking agent containing dynamic chemical bonds and a one-dimensional conductive material in a certain proportion; the ratio of linear polyurethane precursor A to anionic linear polyurethane precursor B in the conductive paste is 0.25~4; the ratio of polyurethane precursor to multi-hydroxy crosslinking agent containing dynamic chemical bonds is 0.6~1.5; and the ratio of polyurethane precursor to one-dimensional conductive material is 0.5~2. (5) Finally, the coated film is dried to obtain a stretchable current collector based on self-healing polyurethane.

2. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The initial square resistance of the self-healing polyurethane-based stretchable fluidic is less than 200 Ω sq −1 , the elongation at break is greater than 550%, and the square resistance after the stretchable fluidic is applied to a tensile strain of 550% and returned to the original length is no more than 10 times the initial square resistance.

3. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The diisocyanate in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of isophorone diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and toluene diisocyanate.

4. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The polyether diol used in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran.

5. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The alkyl diol / amine in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of ethylene glycol, propylene glycol, 1,4-butanediol, ethylenediamine, and propylenediamine.

6. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The sulfonic acid diol / amine in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of sodium ethylenediamine ethanesulfonate and sodium N,N-di(2-hydroxyethyl)-2-aminoethanesulfonate.

7. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The one-dimensional conductive material in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of carbon nanotubes, polythiophene nanowires, silver nanowires, copper nanowires, and gold nanowires.

8. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The organic solvent in the preparation method of the stretchable current collector based on self-healing polyurethane is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and acetone.

9. The stretchable current collector based on self-healing polyurethane according to claim 1, characterized in that, The drying temperature is 40~100℃.

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