Double-sided modification method of barrier layer material in battery application soft package film

Abstract

The application relates to the technical field of battery packaging, in particular to a double-face modification method of a barrier layer material in a soft package packaging film for a battery, a double-face modification method of a barrier layer material in a soft package packaging film for a battery, which comprises the following steps: S1, unwinding a metal foil; S2, preparing a Si-Ti chelate multi-claw silane solution; S3, coating the Si-Ti chelate multi-claw silane solution on both sides of the metal foil under the assistance of plasma by means of sputtering and / or roller coating to form a Si-Ti chelate multi-claw silane dense layer; and S5, winding. By adopting the plasma combined sputtering and / or roller coating technology to coat the Si-Ti chelate multi-claw silane dense layer on both sides of the metal foil, the contact surface of electrolyte and the metal foil is blocked, the electrolyte can effectively block the corrosion of the surface of the metal foil, the generation of pinholes and air permeability of the aluminum foil in the deep drawing process is prevented, and the corrosion resistance is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery packaging, in particular to a double-face modification method of a barrier layer material in a soft package packaging film for a battery. BACKGROUND

[0002] In recent years, with the increase of lithium battery technology and output, the demand for lithium battery packaging materials is also increasing. In addition to the traditional steel shell or metal shell, the metal-plastic composite film (also known as a soft packaging film) is also an important way for battery packaging. The soft package battery prepared by the soft packaging film has the characteristics of high energy density and high battery safety, and the soft packaging film has become the mainstream of the application and development of future battery packaging materials.

[0003] The traditional battery packaging soft film is basically composed of an outer protective layer, an intermediate barrier layer and an inner heat sealing layer. The layers are bonded by an adhesive. The combination of the multilayer structure can effectively improve the heat sealing performance, barrier performance, electrolyte resistance, deep drawing performance and friction resistance and insulation performance of the material. In the multilayer composite material, the intermediate barrier layer is composed of a metal foil, which mainly prevents water and gas from entering the battery core, affecting the composition or performance of the electrolyte or electrolyte. It is a very critical layer of material for the soft packaging film. However, during the deep drawing process of the soft packaging film, there will be different degrees of material thinning at the corners of the deep drawing groove. During the deep drawing and thinning of the metal foil, pinholes and air permeability problems will occur.

[0004] Therefore, effectively solving the pinhole and air permeability problems occurring in the deep drawing process of the metal foil is of great significance to the development of the barrier layer. SUMMARY

[0005] In order to avoid the generation of pinholes and air permeability problems during the deep drawing and thinning of the metal foil, the application provides a double-face modification method of a barrier layer material in a soft package packaging film for a battery.

[0006] The application provides a double-face modification method of a barrier layer material in a soft package packaging film for a battery, which adopts the following technical scheme:

[0007] A double-face modification method of a barrier layer material in a soft package packaging film for a battery, comprising the following steps:

[0008] S1, unwinding the metal foil;

[0009] S2, preparing a Si-Ti chelated multi-claw silane solution; the preparation method of the Si-Ti chelated multi-claw silane solution is that the multi-claw silane is solidified into Si-Ti chelated multi-claw silane by titanium chelate, and then diluted by an organic solvent to obtain;

[0010] S3, coating Si-Ti chelate multi-pronged silane solution on both sides of the metal foil by sputtering and / or roller coating in the presence of plasma to form a dense Si-Ti chelate multi-pronged silane layer;

[0011] S5, winding.

[0012] By adopting the above technical solution, the Si-Ti chelate multi-pronged silane realizes the improvement of the surface density of the metal foil; at the same time, the Si-Ti chelate multi-pronged silane plays a role in blocking the contact surface between the electrolyte and the metal foil, which can effectively block the corrosion of the electrolyte on the surface of the metal foil, prevent the generation of pinholes and air permeability of the aluminum foil in the deep drawing process, and improve the corrosion resistance. The application adopts plasma combined with sputtering and / or roller coating technology, which not only significantly improves the interface between the Si-Ti chelate multi-pronged silane dense layer and the metal foil, increases their compatibility, makes the combination of the Si-Ti chelate multi-pronged silane dense layer and the metal foil more perfect and the adhesion more firm, but also can endow the metal foil with special application performance, so that the metal foil has long-term excellent adhesion and insulation characteristics under the charging and discharging of the electrolyte environment.

[0013] In a specific implementation scheme, S3 and S5 further include S4, specifically: molecular solidification and bond energy strengthening are performed by microwave reaction to realize the solidification effect of the Si-Ti chelate multi-pronged silane solution on the surface of the metal foil.

[0014] By adopting the above technical solution, the microwave is used to match the Si-Ti chelate multi-pronged silane with long wave energy, and then acts on the double bond, triple bond and unsaturated group at the interface in a directional manner, so as to saturate the unsaturated interface, thereby greatly reducing the interface polarity, making the film layer and the metal foil no longer have an interface, and greatly reducing the probability of interlayer peeling of the metal foil in application.

[0015] In a specific implementation scheme, in S1, the metal foil is one or more of aluminum foil, copper foil, stainless steel foil, nickel foil and tin foil; preferably aluminum foil, copper foil and stainless steel foil.

[0016] By adopting the above technical solution, the aluminum foil itself has good elongation and tensile strength, which can meet the cold stamping forming, and at the same time, due to its high water and oxygen resistance, it can physically isolate the penetration of water and oxygen from the outside to the inside of the battery core;

[0017] The copper foil has low surface oxygen characteristics, can be attached to various different substrates such as metals, insulating materials, etc., has a wide temperature use range, and can physically isolate the penetration of water and oxygen from the outside to the inside of the battery core;

[0018] The stainless steel foil is not easy to be broken in the stamping process, and the stainless steel foil is not easy to be deformed and has certain hardness, so that certain pressure can be applied when the battery expands and gas is generated inside, thereby avoiding the situation of aggravating the battery polarization and aging.

[0019] In a specific embodiment, the metal foil is a stainless steel foil, and the surface of the stainless steel foil is cleaned by plasma.

[0020] By using the above technical solution, the hydrogen embrittlement phenomenon of the steel foil generated by the traditional pickling oil removal process is avoided, the puncture strength of the stainless steel foil is improved, and the surface of the stainless steel foil is changed from non-polar and difficult adhesion to certain polarity, easy adhesion and hydrophilicity, which is more conducive to the combination of the stainless steel foil and the Si-Ti chelated multi-claw silane dense layer.

[0021] In a specific embodiment, when the surface of the stainless steel foil is cleaned by plasma, the power used is 450-550 W, and the current is 1.5-2.2 A.

[0022] By using the above technical solution, the power and current during cleaning are optimized to improve the cleaning effect and efficiency.

[0023] In a specific embodiment, after the surface of the stainless steel foil is cleaned and the oil is removed, an electrochemical corrosion treatment is further included, which specifically comprises: placing the stainless steel foil after oil removal and acid pickling treatment into an anodic oxidation electrolyte for direct current anodic oxidation and then drying to form an oxide film, and the direct current voltage is 20-40 V, the current density is 5-10 A / dm 2 , and the oxidation time is 15-30 min.

[0024] By using the above technical solution, an oxide film is generated on the surface of the stainless steel foil under the electrochemical corrosion treatment, and there are many honeycomb pores on the oxide film; this is conducive to the penetration of more Si-Ti chelated multi-claw silane into the stainless steel foil, improves the peeling force between the Si-Ti chelated multi-claw silane and the stainless steel foil, and further improves the combination of the two.

[0025] In a specific embodiment, the electrolyte is a water solution of 30-50 g / L oxygen-containing acid, 0.5-2 g / L chromate, and 1-5 g / L nickel salt, and the oxygen-containing acid is one or more of sulfuric acid, nitric acid, perchloric acid, and phosphoric acid.

[0026] By using the above technical solution, the electrolyte composition is simple, the solution is stable, the performance of the film layer can be improved, the wear resistance and temperature resistance of the film layer can be improved without affecting the growth speed of the oxide film; the addition of chromate improves the uniformity of the film layer, and the addition of nickel salt accelerates the growth speed of the film.

[0027] In one specific implementation, the Si-Ti chelate multi-pronged silane solution has a mass concentration of 10-90% in S2; preferably, the mass concentration is 30-50%.

[0028] By using the above technical solution, when the silane concentration is 30-90%, the decomposition of SiH4 and the film deposition process is much greater than the etching process of H radical on weak Si-Si bond, and the reaction under such non-equilibrium forms a metastable structure of α-Si(H film); when the silane concentration is reduced to below 30%, due to the reduction of silane concentration, the concentration of main precursor groups such as SiH3 is reduced, and the surface of the metal foil is covered with H radical; when SiH3 is adsorbed to the substrate, it reacts with the surface Si-H bond to release Si and H2, which promotes the full crystallization of the film, and a large number of atomic H penetrate into the subsurface region to form a flexible network with a sufficient number of atomic H in the subsurface, which promotes crystallization by eliminating the tightly bound Si-Si bond in the amorphous lattice through structural relaxation; when the silane concentration is further reduced to 10%, the decomposition of SiH4 and the film deposition process is still greater than the etching process of H radical on weak Si-Si bond, but H radical still has a certain etching effect, and the film formed at this time has a certain chemical stability, but the crystalline component is not large enough to form an interface structure.

[0029] Secondly, as the silane concentration increases, the film deposition rate gradually increases, but when the silane concentration is 30-50%, the deposition rate of the film increases rapidly; but when the silane concentration is 50-90%, the deposition rate increases slowly and gradually stabilizes.

[0030] Therefore, selecting a suitable mass concentration of Si-Ti chelate multi-pronged silane solution can control the crystallization state and deposition rate of the formed film, thereby improving the density of the film.

[0031] In one specific implementation, the Si-Ti chelate multi-pronged silane solution has a mass concentration of 10-90% in S2; preferably, the mass concentration is 30-50%.

[0032] By using the above technical solution, a thicker film layer has higher hardness, and a thinner film layer is more flexible; optimizing the thickness of the Si-Ti chelate multi-pronged silane dense layer can balance the hardness and flexibility of the film layer, so that it can not only meet the cold stamping forming, but also can exert a certain pressure when the battery expands and internal gas is generated, avoiding the situation of aggravating the polarization and aging of the battery.

[0033] In one specific implementation, the plasma and microwave action time is 0.1-30s in S3 and S4.

[0034] By adopting the technical scheme, the residence time of the metal foil in the plasma cavity and the microwave cavity is controlled through the walking speed; after the metal foil is treated by plasma, the surface thereof is etched and activated, the grafted functional Si-Ti chelate multi-claw silane can form a chemical covalent bond anchor layer with the organic and inorganic interface in a self-ordered state, such a surface forms a uniform organic-inorganic nanohybrid layer, which is easily infiltrated by a liquid, thereby laying a good foundation for the firm adhesion of the coating layer and each organic and inorganic film layer. The microwave can greatly reduce the interface polarity, the metal foil serves as a microwave reflection material, the microwave energy between the organic and inorganic films can be rapidly accumulated and multiplied, and the interface rapidly forms a covalent bond with higher activation energy under the action of high-energy microwave, so that a low-temperature rapid bonding reaction can be realized, thereby forming a dense three-dimensional integrated interface layer. Through optimization of the plasma and microwave action time, the obtained Si-Ti chelate multi-claw silane dense layer can effectively block the corrosion of the electrolyte to the surface of the metal foil, and prevent the generation of pinholes and air permeability of the metal foil in the deep drawing process and improve the corrosion resistance.

[0035] To sum up, the present application includes at least one of the following beneficial technical effects:

[0036] 1. The present application adopts plasma combined with sputtering and / or roll coating technology to coat Si-Ti chelate multi-claw silane dense layer on both sides of the metal foil, which blocks the contact surface between the electrolyte and the metal foil, can effectively block the corrosion of the electrolyte to the surface of the metal foil, prevent the generation of pinholes and air permeability of the aluminum foil in the deep drawing process and improve the corrosion resistance;

[0037] 2. In the present application, the microwave technology is used to cure the Si-Ti chelate multi-claw silane dense layer, which reduces the interface polarity, so that there is no interface between the film layer and the metal foil, thereby greatly reducing the probability of interlayer peeling of the metal foil in application; 3. The present application optimally selects stainless steel foil as the metal foil. The surface of the stainless steel foil is not easy to be scratched during stamping forming, and the stainless steel foil is not easy to deform and has a certain hardness, which can exert a certain pressure when the battery expands and internal gas is generated, thereby avoiding the situation that the use of aluminum foil aggravates the polarization and aging of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The present application is a method for modifying the structure of the metal foil in the soft package film for battery application.

[0039] BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION

[0040] The following will be described by examples and drawings Figure 1 The present application will be further described in detail.

[0041] Preparation Example

[0042] Preparation Example 1

[0043] The present preparation example discloses a preparation method of a stainless steel foil, comprising the following steps:

[0044] P1, take a stainless steel foil with a thickness of 40 μm, clean the surface of the stainless steel foil by using low-temperature plasma, and remove the oil stains on the surface of the stainless steel foil; when cleaning the surface of the stainless steel foil, the power size of the cleaning machine is 450 W, and the current is 1.5 A;

[0045] P2, place the treated stainless steel foil into an anodizing electrolyte to perform direct current anodizing; when performing direct current anodizing, the direct current voltage is 20 V, the current density is 1 A / dm 2 , the anodizing solution temperature is 25℃, the oxidation time is 30 min, and after oxidation, the stainless steel foil is dried to form an anodizing film with a thickness of 800 nm on the surface of the stainless steel foil; wherein the electrolyte is a mixed solution formed by adding 30 g of sulfuric acid, 2 g of sodium chromate and 5 g of nickel sulfate into 1 L of deionized water; in other preparation examples, sulfuric acid can be replaced by one or more of nitric acid, perchloric acid and phosphoric acid.

[0046] Preparation Example 2

[0047] The present preparation example discloses a preparation method of a stainless steel foil, comprising the following steps:

[0048] P1, take a stainless steel foil with a thickness of 40 μm, clean the surface of the stainless steel foil by using low-temperature plasma, and remove the oil stains on the surface of the stainless steel foil; when cleaning the surface of the stainless steel foil, the power size of the cleaning machine is 450 W, and the current is 1.5 A;

[0049] P2, place the treated stainless steel foil into an anodizing electrolyte to perform direct current anodizing; when performing direct current anodizing, the direct current voltage is 20 V, the current density is 1 A / dm 2 , the anodizing solution temperature is 25℃, the oxidation time is 30 min, and after oxidation, the stainless steel foil is dried to form an anodizing film with a thickness of 800 nm on the surface of the stainless steel foil; wherein the electrolyte is a mixed solution formed by adding 30 g of sulfuric acid, 2 g of sodium chromate and 5 g of nickel sulfate into 1 L of deionized water; in other preparation examples, sulfuric acid can be replaced by one or more of nitric acid, perchloric acid and phosphoric acid.

[0050] Embodiment

[0051] Embodiment 1

[0052] The present embodiment discloses a method for modifying both sides of a barrier layer material in a soft package film for battery applications, comprising the following steps:

[0053] S1, the aluminum foil with a thickness of 40 μm is unwound on the unwinding machine at a speed of 2 m / s; in other embodiments, the aluminum foil can be replaced by copper foil;

[0054] S2, 10 g of bis(triethoxysilyl)ethane (bis-silane) is weighed and reacted with 10 g of bis(triethanolamine) titanium diisopropyl titanate (titanium chelate) to obtain Si-Ti chelated multi-silane; 10 g of Si-Ti chelated multi-silane is dissolved in 90 g of ethyl acetate (organic solvent) to form a Si-Ti chelated multi-silane solution for use;

[0055] S3, the surface of the aluminum foil is treated by plasma bombardment using a plasma source to remove impurities on the surface of the aluminum foil while etching and activating; then the aluminum foil to be treated is fixed on the substrate holder of the vacuum magnetron sputtering film coating equipment, and the Si-Ti chelated multi-silane solution is prepared for magnetron sputtering film coating, and a dense layer 1 of Si-Ti chelated multi-silane with a thickness of 0.05 μm is deposited on the surface of the aluminum foil by using a direct current vacuum magnetron sputtering process; wherein the vacuum degree is 5 x 10 -3 Pa, process atmosphere 0.5 Pa, heating temperature 100℃, ion source power 1 kw, action time 5S, coating speed and unwinding speed consistent with 2 m / s;

[0056] S5, the aluminum foil after the above film coating is wound on the winding machine at a speed of 2 m / s.

[0057] Example 2

[0058] This example is basically the same as example 1, the difference is that in S2, 10 g of 1,1,2-tri(ethoxysilyl)ethane (tri-silane) is reacted with 10 g of (triethanolamine) titanium isopropyl titanate complex (titanium chelate) to obtain Si-Ti chelated multi-silane; 10 g of Si-Ti chelated multi-silane is dissolved in 90 g of acrylic acid (organic solvent) to form a Si-Ti chelated multi-silane solution for use.

[0059] Example 3

[0060] This example is basically the same as example 2, the difference is that S4 is additionally provided between S3 and S5, specifically: the above aluminum foil after film coating is further subjected to molecular solidification and bond energy strengthening in a microwave reaction kettle to realize the solidification effect of Si-Ti chelated multi-silane solution on the surface of the metal foil; wherein the wavelength is 100 mm, the frequency is 3000 MHz, and the action time is 5S.

[0061] Example 4

[0062] This example is basically the same as example 3, except that in S2, 30g Si-Ti chelate multi-claw silane is weighed and dissolved in 70g ethyl acetate, and stirred uniformly to form a Si-Ti chelate multi-claw silane solution for standby use.

[0063] Example 5

[0064] This example is basically the same as example 3, except that in S2, 35g Si-Ti chelate multi-claw silane is weighed and dissolved in 65g ethyl acetate, and stirred uniformly to form a Si-Ti chelate multi-claw silane solution for standby use.

[0065] Example 6

[0066] This example is basically the same as example 3, except that in S2, 50g Si-Ti chelate multi-claw silane is weighed and dissolved in 50g ethyl acetate, and stirred uniformly to form a Si-Ti chelate multi-claw silane solution for standby use.

[0067] Example 7

[0068] This example is basically the same as example 3, except that in S2, 90g Si-Ti chelate multi-claw silane is weighed and dissolved in 10g ethyl acetate, and stirred uniformly to form a Si-Ti chelate multi-claw silane solution for standby use.

[0069] Example 8

[0070] This example is basically the same as example 5, except that in S1, the stainless steel foil is unwound on a unwinding machine at a speed of 2m / s, wherein the stainless steel foil is obtained from preparation example 1.

[0071] Example 9

[0072] This example is basically the same as example 5, except that in S1, the stainless steel foil is unwound on a unwinding machine at a speed of 2m / s, wherein the stainless steel foil is obtained from preparation example 2.

[0073] Example 10

[0074] This example is basically the same as example 8, except that in S3, the surface of the aluminum foil is treated by plasma bombardment using a plasma source to remove impurities on the surface of the aluminum foil while etching and activating; the aluminum foil to be treated is then fixed on a substrate holder of a vacuum magnetron sputtering film coating device, and a Si-Ti chelate multi-claw silane solution is prepared for magnetron sputtering film coating, and the Si-Ti chelate multi-claw silane solution is used for 2 times of direct current vacuum magnetron sputtering process to deposit a Si-Ti chelate multi-claw silane dense layer 1 with a thickness of 0.1μm on the surface of the aluminum foil; wherein the vacuum degree is 5×10 -3Pa, process atmosphere 0.5 Pa, heating temperature 100°C, ion source power 1 kw, action time 5S, film deposition speed and unwinding speed keep consistent at 2m / s.

[0075] Example 11

[0076] This example is basically the same as Example 8, except that S3, the aluminum foil surface is treated by plasma bombardment using a plasma source to remove the aluminum foil surface impurities while etching and activating; then the aluminum foil to be treated is fixed on the substrate holder of the vacuum magnetron sputtering film coating equipment, preparing for magnetron sputtering film coating, and putting into Si-Ti chelate multi-claw silane solution, using 4 times of direct current vacuum magnetron sputtering process to deposit a thickness of 0.2μm Si-Ti chelate multi-claw silane dense layer 1 on the aluminum foil surface; wherein the vacuum degree is 5x10 -3 Pa, process atmosphere 0.5 Pa, heating temperature 100°C, ion source power 1 kw, action time 5S, film deposition speed and unwinding speed keep consistent at 2m / s.

[0077] Example 12

[0078] This example is basically the same as Example 8, except that S3, the aluminum foil surface is treated by plasma bombardment using a plasma source to remove the aluminum foil surface impurities while etching and activating; then the aluminum foil to be treated is fixed on the substrate holder of the vacuum magnetron sputtering film coating equipment, preparing for magnetron sputtering film coating, and putting into Si-Ti chelate multi-claw silane solution, using 6 times of direct current vacuum magnetron sputtering process to deposit a thickness of 0.3μm Si-Ti chelate multi-claw silane dense layer 1 on the aluminum foil surface; wherein the vacuum degree is 5x10 -3 Pa, process atmosphere 0.5 Pa, heating temperature 100°C, ion source power 1 kw, action time 5S, film deposition speed and unwinding speed keep consistent at 2m / s.

[0079] Example 13

[0080] This example is basically the same as Example 8, except that S3, the aluminum foil surface is treated by plasma bombardment using a plasma source to remove the aluminum foil surface impurities while etching and activating; then the aluminum foil to be treated is fixed on the substrate holder of the vacuum magnetron sputtering film coating equipment, preparing for magnetron sputtering film coating, and putting into Si-Ti chelate multi-claw silane solution, using 20 times of direct current vacuum magnetron sputtering process to deposit a thickness of 1μm Si-Ti chelate multi-claw silane dense layer 1 on the aluminum foil surface; wherein the vacuum degree is 5x10 -3 Pa, process atmosphere 0.5 Pa, heating temperature 100°C, ion source power 1 kw, action time 5S, film deposition speed and unwinding speed keep consistent at 2m / s.

[0081] Example 14

[0082] This example is basically the same as example 11, except that in S3, the vacuum magnetron sputtering is replaced by roll coating, and the specific process is as follows: S3, the surface of the aluminum foil is treated by plasma bombardment using a plasma source to remove impurities on the surface of the aluminum foil while etching and activating; the Si-Ti chelate multi-claw silane solution is uniformly coated on the stainless steel foil by a rotating roller, and a 0.2 μm thick Si-Ti chelate multi-claw silane dense layer 1 is deposited on the surface of the aluminum foil; the roller speed and the unwinding speed are kept consistent at 2 m / s.

[0083] Example 15

[0084] This example is basically the same as example 11, except that in S3, the vacuum magnetron sputtering is replaced by roll coating and vacuum magnetron sputtering combined process, and the specific process is as follows: S3, the surface of the aluminum foil is treated by plasma bombardment using a plasma source to remove impurities on the surface of the aluminum foil while etching and activating; the Si-Ti chelate multi-claw silane solution is uniformly coated on the stainless steel foil by a rotating roller, and a 0.2 μm thick first Si-Ti chelate multi-claw silane dense layer is deposited on the surface of the aluminum foil; the aluminum foil with the first Si-Ti chelate multi-claw silane dense layer coated on the surface is fixed on the substrate holder of the vacuum magnetron sputtering coating device, ready for magnetron sputtering coating, and Si-Ti chelate multi-claw silane solution is put in, and a 0.2 μm thick Si-Ti chelate multi-claw silane dense layer 1 is deposited on the surface of the aluminum foil by twice direct current vacuum magnetron sputtering process; the roller speed and the unwinding speed are kept consistent at 2 m / s; wherein the vacuum degree is 5 x 10 -3 Pa, the process atmosphere is 0.5 Pa, the heating temperature is 100°C, the ion source power is 1 kw, the action time is 5 s, and the coating speed and the unwinding speed are kept consistent at 2 m / s.

[0085] Example 16

[0086] This example is basically the same as example 11, except that the unwinding speed in S1 and the winding speed in S5 are 0.33 m / s, and the plasma and microwave action time is 30 s.

[0087] Example 17

[0088] This example is basically the same as example 11, except that the unwinding speed in S1 and the winding speed in S5 are 100 m / s, and the plasma and microwave action time is 0.1 s.

[0089] Comparative Example

[0090] Comparative Example 1

[0091] This comparative example is different from example 1 in that the aluminum foil is not treated.

[0092] Performance detection

[0093] 1. The metal foil formed by Examples 1-17 and Comparative Example 1 was subjected to PP and PA compounding, and the peel strength was tested in accordance with the provisions of GB / T 8808-1988, the tensile speed was (300±50) mm / min, the tensile direction was T-shaped with the unpeeling direction, and the results are shown in Table 1.

[0094] 2. The metal foil formed by Examples 1-17 and Comparative Example 1 was soaked in an electrolyte at 80°C for 1 h, then taken out and dried, and the surface pinhole condition of the metal foil was observed under the light of a flashlight in a dark room, and the results are shown in Table 1.

[0095] 3. The metal foil formed by Examples 1-17 and Comparative Example 1 was subjected to slow impact test, the deep drawing depth was 3.6 mm, and the deep drawing corner (R angle) was observed, and the surface pinhole condition of the deep drawing corner of the aluminum foil was observed under the light of a flashlight in a dark room, and the results are shown in Table 1.

[0096] Table 1 Performance detection data table of Examples 1-17 and Comparative Example 1

[0097]

[0098] As Figure 1 shown, the present application modifies both sides of the metal foil 2, i.e. the two sides close to the outer protective layer and the inner heat-sealing layer are coated with a Si-Ti chelated multi-claw silane dense layer 1. The Si-Ti chelated multi-claw silane dense layer 1 realizes the improvement of the surface density of the metal foil 2, blocks the contact surface between the electrolyte and the metal foil 2, can effectively block the corrosion of the electrolyte on the surface of the metal foil 2, and prevents the generation of pinholes and air permeability and improves the corrosion resistance of the metal foil 2 during deep drawing.

[0099] Referring to Table 1, in combination with Example 1 and Comparative Example 1, it can be seen that by coating the Si-Ti chelated multi-claw silane dense layer 1 on both sides of the aluminum foil, the peel strength and corrosion resistance between the aluminum foil layer and the PP or PA layer are improved. The surface of the aluminum foil is subjected to ion source plasma bombardment treatment to remove impurities on the surface of the aluminum foil, and then a thin film Si-Ti chelated multi-claw silane dense layer 1 is deposited on the surface of the aluminum foil by a direct current vacuum magnetron sputtering process. The Si-Ti chelated multi-claw silane dense layer 1 can effectively block the corrosion of the electrolyte on the surface of the aluminum foil, prevent the generation of pinholes and air permeability during deep drawing of the aluminum foil, and improve the corrosion resistance of the aluminum foil.

[0100] Referring to Table 1, in combination with Examples 1 and 3, it can be seen that the Si-Ti chelate multi-claw silane is solidified and the bond energy is strengthened on the aluminum foil by using microwave after coating, the solidification effect of the Si-Ti chelate multi-claw silane on the surface of the aluminum foil is realized, and the peeling strength between the aluminum foil and the PP or PA layer is improved.

[0101] Referring to Table 1, in combination with Examples 1, 4-7, it can be seen that the peeling strength and corrosion resistance between the aluminum foil and the PP or PA layer are obtained by changing the mass concentration of the Si-Ti chelate multi-claw silane solution in a proper range; in particular, when the mass concentration of the Si-Ti chelate multi-claw silane solution is 35%, the peeling strength between the aluminum foil and the PP or PA layer is optimal; selecting a proper mass concentration of the Si-Ti chelate multi-claw silane solution can control the crystallization state and deposition rate of the formed film, thereby improving the density of the film layer and obtaining good peeling strength and corrosion resistance.

[0102] Referring to Table 1, in combination with Examples 1, 8 and 9, it can be seen that the peeling strength between the stainless steel foil and the PP or PA layer can be further improved after the stainless steel foil is first treated by plasma and electrochemistry and then modified on both sides; the hydrogen embrittlement phenomenon of the steel foil generated by the traditional acid pickling oil removal process is avoided by using plasma to remove oil on the surface of the stainless steel foil, the puncture strength of the stainless steel foil is improved, and at the same time, the surface of the stainless steel foil is changed from non-polar and difficult adhesion to a certain polarity, easy adhesion and hydrophilicity, which is more conducive to the combination of the stainless steel foil and the Si-Ti chelate multi-claw silane dense layer 1; secondly, by anodizing the stainless steel foil, an oxide film is grown on the surface of the stainless steel foil, and there are many cavities on the oxide film, which is conducive to the penetration of more Si-Ti chelate multi-claw silane into the stainless steel foil, thereby improving the peeling force between the Si-Ti chelate multi-claw silane dense layer 1 and the stainless steel foil and further improving the combination of the two, so that the peeling strength between the stainless steel foil and the PP or PA layer is further effectively improved on the basis of retaining the advantages of the aluminum-plastic composite film packaging material.

[0103] Referring to Table 1, in combination with Examples 8, 10-13, it can be seen that by changing the number of magnetron sputtering in a proper range, Si-Ti chelate multi-claw silane dense layers 1 of different thicknesses are obtained, and the stainless steel foils obtained have good peeling strength and corrosion resistance with the PP or PA layer; when the thickness of the Si-Ti chelate multi-claw silane dense layer is 0.2 μm, the peeling strength and corrosion resistance between the stainless steel foil and the PP or PA layer are optimal; a proper thickness of the Si-Ti chelate multi-claw silane dense layer 1 can balance the hardness and flexibility of the film layer, so that it can not only meet the cold stamping forming, but also can exert a certain pressure when the battery expands and gas is generated inside, thereby avoiding the aggravation of battery polarization and aging.

[0104] Referring to Table 1, in combination with Examples 11, 16 and 17, it can be seen that the residence time of the stainless steel foil in the plasma cavity and the microwave cavity is controlled by the winding speed, and the stainless steel foil has good peel strength and corrosion resistance between the PP or PA layer; after the stainless steel foil is treated by plasma, the surface is etched and activated, and the grafted functional Si-Ti chelate multi-claw silane can form a chemical covalent bond anchor layer with the organic and inorganic interface in a self-ordered state, such a surface forms a uniform organic-inorganic nanohybrid layer, which is easily infiltrated by liquid, and lays a good foundation for the firm adhesion of the coating layer and each organic and inorganic film layer; the microwave can greatly reduce the interface polarity, the stainless steel foil is used as a microwave reflecting material, the microwave energy between the organic and inorganic films can be rapidly accumulated and multiplied, the interface rapidly forms a covalent bond with higher activation energy under the action of high-energy microwave, and a low-temperature rapid bonding reaction can be realized, so that a dense three-dimensional integrated interface layer is formed. By optimizing the plasma and microwave action time, the dense Si-Ti chelate multi-claw silane layer 1 can effectively block the corrosion of the electrolyte to the surface of the stainless steel foil, prevent the generation of pinholes and air permeability of the stainless steel foil during deep drawing, and improve the corrosion resistance.

[0105] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the Patent Law.

Claims

1. A method for double-sided modification of barrier layer materials in a soft package film for batteries, characterized by: The following steps are involved: S1, unwinding the metal foil (2); S2, preparing a Si-Ti chelated polydactyl silane solution; the Si-Ti chelated polydactyl silane solution is prepared by curing polydactyl silane with a titanium chelate to form Si-Ti chelated polydactyl silane, and then diluting the solution with an organic solvent; S3, applying a Si-Ti chelated polydactyl silane solution to both sides of the metal foil under plasma assistance by sputtering to form a Si-Ti chelated polydactyl silane dense layer (1); S5, winding; The polydactyl silane is selected from bis(triethoxysilyl)ethane or 1,1,2-tri(ethoxysilyl)ethane; S4 is also included between S3 and S5, specifically: molecular curing and bond energy strengthening are performed through microwave reaction to achieve the curing effect of Si-Ti chelated multi-claw silane solution on the surface of the metal foil (2); In S1, the metal foil (2) is a stainless steel foil; and plasma is used to clean and degrease the surface of the stainless steel foil; After the surface of the stainless steel foil is cleaned and degreased, it is subjected to electrochemical corrosion treatment. Specifically, the stainless steel foil after degreasing and pickling is placed in an anodic oxidation electrolyte for DC anodization and then dried to form an oxide film. The DC voltage is 20-40V and the current density is 5-10A / dm 2 , oxidation time is 15-30min; The electrolyte is an aqueous solution of 30-50 g / L of oxygen-containing acid, 0.5-2 g / L of chromate and 1-5 g / L of nickel salt, wherein the oxygen-containing acid is one or more of sulfuric acid, nitric acid, perchloric acid and phosphoric acid.

2. The method for double-sided modification of the barrier layer material in the soft package film for batteries according to claim 1, characterized in that: When the plasma is used to clean the surface of the stainless steel foil, the power used is 450-550W and the current is 1.5-2.2A.

3. The method for double-sided modification of the barrier layer material in the soft package film for batteries according to claim 1, characterized in that: In S2, the mass concentration of the Si-Ti chelating multi-clawed silane solution is 10-90%.

4. The method for double-sided modification of the barrier layer material in the soft package film for batteries according to claim 1, characterized in that: In the S3, the thickness of the Si-Ti chelated multi-clawed silane dense layer (1) is 0.05-1 μm.

5. The method for double-sided modification of the barrier layer material in the soft package film for batteries according to claim 1, characterized in that: In S3 and S4, the plasma and microwave action time is 0.1-30s.

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