A kind of armored and corrosion integrated corrosion-resistant energy storage system power cable

Abstract

The application relates to the technical field of electric wire and cable, and discloses a kind of armored and corrosion integrated corrosion-resistant energy storage system power cable, to solve the weak interface combination of armored layer and corrosion layer in the prior art, easy to peel under the action of energy storage system temperature difference cycle, leading to the failure of protection function, the service life of cable is shortened, the cable includes conductor layer, conductor shielding layer, insulation layer, insulation shielding layer, inner sheath layer, integrated functional layer and outer sheath layer from inside to outside in sequence;Integrated functional layer is formed by the base material modified by mechanical micro-nano structure and chemical activity, and is compounded with integrated material containing functional filler, and is formed by gradient curing process and integrated co-extrusion molding, which effectively improves the interlayer bonding stability, corrosion resistance and mechanical strength, can adapt to the severe temperature difference environment of energy storage system, reduces the surface cracking, prolongs the service life of cable, and guarantees the long-term safe and stable operation of energy storage system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wire and cable, in particular to a kind of armored and corrosion integrated corrosion-resistant energy storage system power cable. BACKGROUND

[0002] With the rapid development of global energy storage industry, power cable for energy storage system as the core component of power transmission, its working environment is increasingly complex and demanding, often need to face high salt fog, severe temperature difference, microbial corrosion and other extreme conditions, which puts forward high requirements for the corrosion resistance, mechanical protection performance and structural stability of cable. Among them, the armored layer as the key structure of cable mechanical protection, the corrosion layer bears the core role of resisting corrosion medium erosion, and the performance and combination state of the two directly determine the service life and operation safety of the cable.

[0003] At present, the armored and corrosion function of power cable in the prior art is designed and prepared by layering, for example, a kind of cross-linked polyethylene insulated submarine power cable with publication number CN120340943A, by designing the cable body into a layered structure of insulating outer protective layer, tensile resistance layer, corrosion resistance layer, steel belt armored layer and insulating layer, setting conductor insulation shielding layer, conductor shielding layer and conductor water blocking layer inside, filling water blocking powder in the tensile resistance layer and steel belt armored layer and using spiral arranged compression steel belt and steel wire, the adaptation to the high pressure and corrosion environment of submarine is realized, and the problem of cable damage caused by longitudinal diffusion of seawater along the cable gap is solved; A kind of corrosion-resistant armored power cable with publication number CN219778551U, by setting the first corrosion-resistant layer of polytetrafluoroethylene material in the protective outer layer, and setting the shielding layer, insulating layer, second corrosion-resistant layer of FEP film material and wear-resistant layer outside each conductor in turn, and combining with copper wire braided armored layer, separation mechanism and tensioning silk ring, double corrosion-resistant protection is realized for all conductors inside the cable and single conductor after the protective outer layer is peeled off.

[0004] However, the surface of metal armored layer is easy to form inert passivation film naturally, which leads to significant lack of chemical compatibility between the metal armored layer and the high molecular corrosion-resistant layer, and cannot form stable chemical bond connection, but only relies on van der waals force to maintain the interface combination. The severe temperature difference cycle generated in the charging and discharging process of energy storage system will further aggravate the periodic tensile and shear stress generated by the difference in thermal expansion coefficient between the metal armored layer and the high molecular corrosion-resistant layer, leading to the gradual peeling of the interlayer interface and the formation of gap, and the external corrosion medium is easy to invade through the gap, causing the corrosion of armored layer, not only causing the synchronous failure of the mechanical protection performance and corrosion resistance of the cable, but also leading to the performance deterioration of the insulating layer due to corrosion pollution, greatly shortening the service life of the cable, and directly threatening the long-term safe and stable operation of the energy storage system. SUMMARY

[0005] The technical problem to be solved by the present application is that the existing technology has the shortcoming of poor interface combination between the armored layer and the corrosion-resistant layer.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: a kind of armored and corrosion-resistant integrated corrosion-resistant energy storage system power cable, from inside to outside, including conductor layer, conductor shield layer, insulation layer, insulation shield layer, inner sheath layer, integrated functional layer and outer sheath layer;Integrated functional layer gives consideration to mechanical support protection and corrosion barrier function, which is made of armored base material treated by mechanical micro-nano structure and modified by chemical activity, and is compounded with integrated material, and the integrated material is tightly covered on the surface of the modified armored base material.

[0007] Preferably, the thickness of the integrated functional layer is 1.8-2.2mm.

[0008] Preferably, the mechanical micro-nano structure treatment is sand blasting treatment of the surface of the armored base material with white corundum sand with a particle size of 0.22mm, the sand blasting pressure is 0.35-0.4MPa, and the treatment time is 4.2-4.5min, so that the surface roughness Ra of the base material reaches 1.8-2.0μm.

[0009] Preferably, the chemical activity modification is to immerse the base material after sand blasting treatment in a treatment liquid, so as to introduce amino active groups on the surface of the base material and form a physical anchoring structure.

[0010] Preferably, the treatment liquid material includes, by weight: 1.8-2.2 parts of silane coupling agent KH-550, 0.5-0.9 parts of micro-nano alumina particles, 96.5-97.7 parts of ethanol-water solution, 0.04-0.06 parts of glacial acetic acid;The volume ratio of ethanol to water in the ethanol-water solution is 3:7.

[0011] Preferably, the integrated material includes, by weight: 75-80 parts of epoxy modified polyolefin, 3.5-4.1 parts of isocyanate curing agent, 0.6-0.8 parts of photoinitiator, 2.5-3.5 parts of nano zinc oxide, 6-7 parts of chopped glass fiber, 0.12-0.18 parts of calcium stearate, 2.2-2.5 parts of compatibilizer PE-g-MAH.

[0012] Preferably, the content of epoxy groups in the epoxy modified polyolefin is 7-8wt%, the water content is ≤0.05wt%;The water content of isocyanate curing agent is ≤0.02wt%;The water content of photoinitiator is ≤0.03wt%;The particle size of nano zinc oxide is 40-50nm, and the water content is ≤0.1wt%;The length of the chopped glass fiber is 0.3-0.4mm, and the water content is ≤0.1wt%;The water content of calcium stearate and compatibilizer PE-g-MAH is ≤0.05wt%.

[0013] Preferably, the preparation step of the integrated functional layer comprises: S1: first, the surface of the armored substrate is mechanically micro-nano structured, then soaked in sodium hydroxide aqueous solution for degreasing, and finally the armored substrate is immersed in a treatment solution for chemical activation modification to obtain a modified substrate, which is dried for standby; S2: first, the raw materials of the integrated material are dried and pretreated respectively, then the epoxy modified polyolefin is premixed with the compatibilizer, the functional filler is dispersed, and then the curing agent and the photoinitiator are added and mixed at low speed to obtain an integrated composite layer base material; S3: the preheated modified substrate is sent into the center channel of the co-extruder, and the integrated composite layer base material is injected from the side feeding port to form an integrated structure synchronously; S4: the integrated structure is gradiently cured, and then wet grinding, washing and drying are carried out to obtain an integrated functional layer.

[0014] Preferably, in S3, the screw rotation speed of the co-extruder is 65-70 r / min, the barrel temperature is 140-150℃ in the first zone, 160-170℃ in the second zone, and 170-180℃ in the third zone, and the die temperature is 160-165℃; the armored substrate is preheated to 125-135℃ before co-extrusion, and the temperature is maintained for 30-40 min.

[0015] Preferably, in S4, the gradient curing comprises ultraviolet curing and thermal curing in sequence, wherein the ultraviolet curing is performed at a ultraviolet light wavelength of 265 nm, an irradiation intensity of 12.5-13.5 mW / cm 2 , and an irradiation time of 4 min; the thermal curing is performed at a temperature of 130℃ and a holding time of 20-25 min.

[0016] The technical effects and advantages of the present application are as follows: in the present application, an armored and corrosion integrated functional layer is constructed, the armored substrate is subjected to double activation treatment of surface mechanical micro-nano structuring and chemical activity modification, and is combined with an integrated material containing functional fillers to form an integrated structure with mechanical protection and corrosion resistance, effectively solving the problem of weak interface combination between the metal armored layer and the high polymer corrosion resistant layer in the prior art, realizing the synergistic effect of interface chemical combination and physical anchoring, improving the salt mist corrosion resistance, interface peeling strength and tensile strength of the cable, avoiding the failure of protection function caused by interlayer peeling, and prolonging the service life of the cable in harsh environment of energy storage system.

[0017] In the present application, the gradient curing process is adopted in combination with the integrated co-extrusion molding technology, the surface layer is rapidly cured and shaped by ultraviolet light initiation, and then the deep layer material is fully crosslinked by heat curing, which effectively avoids the defects of material surface cracking and insufficient deep layer crosslinking caused by single curing in the prior art, ensures the structural compactness of the integrated functional layer, and at the same time, the co-extrusion molding ensures the close adhesion of the functional layer and other layers of the cable, so that the whole cable has excellent temperature difference cycle performance, can adapt to the severe temperature difference generated by the charging and discharging of the energy storage system, reduce the surface cracking phenomenon, maintain the stability of the insulation resistance, and meet the long-term safe operation demand of the energy storage system. BRIEF DESCRIPTION OF DRAWINGS

[0018] The disclosure of the present application will be described with reference to the accompanying drawings. It should be understood that the drawings are only for illustrative purposes, and are not intended to limit the scope of protection of the present application. In the drawings, the same reference numerals are used to refer to the same parts:

[0019] Figure 1 Preparation flow diagram of the integrated functional layer of the present application; DETAILED DESCRIPTION

[0020] It is easy to understand that, according to the technical scheme of the present application, those skilled in the art can propose a plurality of structure modes and implementation modes which can be replaced with each other without changing the essential spirit of the present application. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical scheme of the present application, and should not be regarded as the whole or as a limitation or restriction on the technical scheme of the present application.

[0021] The application provides a technical scheme: a armored and corrosion-proof integrated corrosion-resistant energy storage system power cable, which comprises the following ring layer structures from inside to outside: a conductor layer: the current carrying basis of the cable, the material is selected from a high-conductivity copper core or aluminum core structure, and the thickness is adjusted according to the current carrying capacity requirement of the cable; a conductor shielding layer: the material is selected from semi-conductive cross-linked polyethylene (XLPE), the thickness is 0.8-1 mm, and the conductor shielding layer is used for uniformizing the electric field on the surface of the conductor, eliminating the distortion of the electric field on the surface of the conductor and avoiding the breakdown of the insulation layer caused by the concentration of the electric field; an insulation layer: the material is selected from XLPE, the thickness is 3-5 mm, and the insulation layer is used for blocking current leakage, guaranteeing the insulation performance of the cable and preventing short circuit accidents; an insulation shielding layer: the material is selected from semi-conductive XLPE, the thickness is 0.8-1 mm, and the insulation shielding layer is used for uniformizing the electric field on the surface of the insulation layer and forming an electric field closed loop with the conductor shielding layer, so as to improve the stability of the insulation system; an inner sheath layer: the material is selected from high-density polyethylene (HDPE), the thickness is 1.5-2 mm, and the inner sheath layer is used for protecting the internal insulation shielding layer and preventing mechanical damage in the subsequent processing and operation process; an integrated functional layer: the thickness is 1.8-2.2 mm, the integrated functional layer takes into account the mechanical support protection function of the armored layer and the corrosion resistance function of the corrosion-proof layer in the prior art, and is composed of a modified base material and an integrated material; and an outer sheath layer: the material is selected from flame-retardant polyethylene (PE), the thickness is 2-2.5 mm, and the outer sheath layer is used for enhancing the mechanical protection capability of the cable.

[0022] It should be particularly pointed out that, in the above-mentioned ring layer structure, the integrated functional layer is the core of the performance optimization of the cable, and the materials and the ratio of the components of the integrated functional layer are as follows: the armored base material is selected from low-carbon steel strips or steel wires, the carbon content is 0.12-0.18 wt%, the tensile strength is greater than or equal to 450 MPa, and the surface of the armored base material is modified by a surface modification material, wherein the surface modification material comprises: 1.8-2.2 parts of a silane coupling agent (KH-550) containing an active amino group, the hydrolysis product of which can react with the hydroxyl group on the surface of the base material through condensation reaction, and can form a chemical bond with the epoxy group in the integrated material, so as to improve the interfacial bonding force between the base material and the composite material; 0.5-0.9 parts of micro-nano aluminum oxide particles with a particle size of 80-100 nm, which can be embedded into the micro-nano concave structure on the surface of the base material after mechanical treatment, so as to form a physical anchoring effect and enhance the interlayer bonding stability; 96.5-97.7 parts of an ethanol-water solution as a dispersion medium for the modified material, the volume ratio of ethanol to water is controlled to be 3:7, so as to ensure uniform hydrolysis of the coupling agent and stable dispersion of the particles; and 0.04-0.06 parts of glacial acetic acid for adjusting the pH of the ethanol-water solution, affecting the hydrolysis reaction rate of KH-550 and ensuring the reaction activity.

[0023] The integrated material is tightly coated on the surface of the modified base material, which is the core material for realizing the synergistic improvement of corrosion prevention function and mechanical property. The proportion and role of each component are as follows: 75-80 parts of epoxy modified polyolefin (POE-g-GMA), wherein the content of epoxy group is 7-8 wt%, and the water content is ≤0.05 wt%. As the corrosion prevention base material, the epoxy group can undergo ring-opening reaction with the amino group on the surface of the modified base material to form a stable chemical bond; 3.5-4.1 parts of isocyanate curing agent (MDI), wherein the water content is ≤0.02 wt%, which can initiate crosslinking of the molecular chain of the epoxy modified polyolefin to improve the structural stability and deformation resistance of the composite material; 0.6-0.8 parts of photoinitiator (type 1173), wherein the water content is ≤0.03 wt%, which can initiate surface curing under ultraviolet light irradiation to avoid cracking and warping of the surface layer during deep curing; 2.5-3.5 parts of nano zinc oxide with a particle size of 40-50 nm and a water content of ≤0.1 wt%, which can adsorb harmful ions in the corrosion medium through ion exchange to strengthen the corrosion prevention performance and improve the thermal stability of the material to resist thermal stress generated by temperature difference cycles caused by charging and discharging of the energy storage system; 6-7 parts of chopped glass fiber with a length of 0.3-0.4 mm and a water content of ≤0.1 wt%, which can improve the tensile and compressive strength of the composite material, enhance the armored protection effect, and prevent the functional layer from being damaged under mechanical stress; 0.12-0.18 parts of calcium stearate as a dispersing agent with a water content of ≤0.05 wt%, which prevents the agglomeration of chopped glass fiber and nano zinc oxide and ensures the uniform dispersion of various fillers in the base material; 2.2-2.5 parts of a compatibilizer (PE-g-MAH) with a water content of ≤0.05 wt%, which improves the interfacial compatibility of chopped glass fiber, nano zinc oxide and epoxy modified polyolefin and improves the overall uniformity of the integrated material. It should be noted that the above materials are commercially available.

[0024] The application also provides a preparation method of the armored and corrosion prevention integrated corrosion-resistant energy storage system power cable integrated functional layer.

[0025] Example 1: According to the above method, the following parameters are used: Figure 1As shown, the embodiment provides a preparation method of armored and corrosion integrated corrosion-resistant energy storage system power cable integrated functional layer, which specifically comprises the following steps: S1: surface activation treatment of armored substrate; S11: mechanical micro-nano structuring treatment: using a press-in sandblasting equipment, selecting white corundum sand with a particle size of 0.22 mm as the sandblasting medium, setting the sandblasting pressure to 0.4 MPa, and performing surface treatment on the low-carbon steel strip, with a treatment time of 4.2 min, so that the substrate surface roughness Ra reaches 2.0 μm, and the dense inert passivation film on the surface is destroyed. S12: chemical degreasing treatment: immersing the substrate treated by sandblasting into a sodium hydroxide aqueous solution with a concentration of 6.5 wt%, controlling the solution temperature to be 56℃, and soaking for 13 min to remove oil stains and residual sand particles on the substrate surface, and then repeatedly rinsing the substrate with deionized water until the pH value of the rinsing liquid reaches 7.0. S13: chemical active modification treatment: weighing 97.25 parts of ethanol-water solution into a container, adding 0.05 parts of glacial acetic acid to adjust the solution pH value to 4.5, then adding 2 parts of KH-550, stirring for 10 min to make it hydrolyze sufficiently; then adding 0.7 parts of micro-nano alumina particles with a particle size of 90 nm, ultrasonic dispersion for 5 min to ensure uniform dispersion of the particles, to obtain a treatment liquid; immersing the degreased substrate into the treatment liquid, controlling the treatment liquid temperature to be 36℃, and soaking for 26 min, so that the hydroxyl groups generated by the hydrolysis of the coupling agent and the hydroxyl groups on the substrate surface undergo condensation reaction, and amino active groups are introduced on the substrate surface; after the treatment is completed, the modified substrate is placed in an oven at 88℃ for drying for 1.5 h, and is ready for use.

[0026] S2: preparation of integrated material; S21: pretreatment of raw materials: weighing 78 parts of epoxy modified polyolefin, 3.8 parts of isocyanate curing agent, 3.0 parts of nano zinc oxide, 6.5 parts of chopped glass fiber, 0.15 parts of calcium stearate, 0.7 parts of photoinitiator, and 2.3 parts of compatibilizer, first drying the epoxy modified polyolefin, nano zinc oxide and chopped glass fiber in a 102℃ oven for 2 h to control the water content of each raw material. S22: premixing of base material: adding the dried epoxy modified polyolefin and compatibilizer into a high-speed mixer, setting the mixer speed to 900 r / min and the temperature to 85℃, and mixing for 12 min to achieve uniform dispersion. S23: dispersion of functional fillers: adding the dried nano zinc oxide, chopped glass fiber and calcium stearate into the mixer in sequence, adjusting the mixer speed to 1300 r / min and the temperature to 95℃, and mixing for 22 min to break the filler agglomerates by high shear force and ensure uniform dispersion of the fillers. S24: fusion of curing system: reducing the temperature of the material in the mixer to 65℃, quickly adding the isocyanate curing agent and the photoinitiator, setting the speed to 400 r / min, and stirring at low speed for 6 min to avoid premature crosslinking reaction of the curing agent, to obtain a uniform integrated composite layer base material.

[0027] S3: integrated co-extrusion; S31: substrate preheating: put the armored substrate after surface activation treatment into the preheating furnace, set the preheating temperature to 130°C, and keep for 35 min to improve the reaction activity of the amino group on the surface of the substrate. S32: co-extrusion: use a three-layer concentric die double-screw co-extrusion machine, set a flow guide ring in the die to ensure the uniformity of the composite layer thickness, set the screw speed to 65 r / min, the barrel temperature to 145°C, 165°C and 175°C in the first, second and third zones respectively, and the die temperature to 165°C; continuously feed the preheated armored substrate into the center channel of the co-extrusion machine, and inject the integrated composite layer base material from the side feeding port to form an integrated structure with a thickness of 2.0 mm.

[0028] S4: post-processing; S41: UV curing: put the co-extruded integrated structure into a UV curing oven, set the UV light wavelength to 265 nm, the irradiation intensity to 12.5 mW / cm 2 , and the irradiation time to 4 min to achieve rapid curing and shaping of the surface layer and avoid cracking of the surface layer during deep layer reaction. S42: thermal curing: transfer the UV-cured integrated structure into a hot air oven, set the temperature to 130°C, and keep for 25 min to promote the chemical bonding of the deep layer epoxy group and the amino group and the full crosslinking of the polymer chain, and improve the stability of the integrated structure. S43: wet grinding and drying: wet grind the integrated structure after thermal curing with an 800-mesh grinding wheel, control the grinding pressure to 0.08 MPa, and remove the small burrs at the die outlet; after grinding, rinse with deionized water and dry in a 60°C oven for 30 min to obtain an integrated functional layer.

[0029] Example 2: This example provides a method for preparing an integrated functional layer of a corrosion-resistant energy storage system power cable with armored and corrosion-resistant integration. Compared with Example 1, the difference lies in adjusting the surface sandblasting process parameters, as follows: use a press-in sandblasting equipment, select white corundum sand with a particle size of 0.22 mm as the sandblasting medium, set the sandblasting pressure to 0.35 MPa, and treat the low-carbon steel strip on the surface for 4.5 min to make the surface roughness Ra of the substrate reach 1.8 μm and destroy the dense inert passivation film on the surface; to verify the influence of the micro-nano structure on the substrate surface on the subsequent interface physical anchoring effect and interface bonding force under the condition of low sandblasting pressure and low surface roughness.

[0030] Example 3: The embodiment provides a preparation method of the armored and corrosion- integrated corrosion-resistant energy storage system power cable integrated functional layer, compared with example 1, the difference lies in adjusting the material ratio and parameters of the chemical modification of the substrate surface, as follows: 97.05 parts of ethanol-water solution is weighed and placed in a container, 0.05 parts of glacial acetic acid is added to adjust the pH value of the solution to 5.0, then 2.2 parts of KH-550 is added, stirring for 10 minutes to make it hydrolyze fully; then 0.7 parts of micro-nano alumina particles with a particle size of 90 nm are added, and ultrasonic dispersion is carried out for 5 minutes; the degreased substrate is immersed in the treatment solution, the temperature of the treatment solution is controlled at 36°C, and the soaking time is 26 minutes; after treatment, dry according to the conditions of example 1 for standby; the purpose is to verify the effect of high silane coupling agent dosage and higher pH value on the improvement of amino introduction efficiency and chemical bonding strength.

[0031] Example 4: The embodiment provides a preparation method of the armored and corrosion- integrated corrosion-resistant energy storage system power cable integrated functional layer, compared with example 1, the difference lies in adjusting the amount of epoxy modified polyolefin in the integrated material, as follows: 75 parts of epoxy modified polyolefin, 3.8 parts of isocyanate curing agent, 3.0 parts of nano zinc oxide, 6.5 parts of chopped glass fiber, 0.15 parts of calcium stearate, 0.7 parts of photoinitiator and 2.3 parts of compatibilizer are weighed, and the raw material drying and subsequent mixing and curing steps are completed according to the conditions of example 1; the purpose is to verify the influence of the reduction of the amount of corrosion-resistant base material on the interface reaction site density and the support ability of the corrosion-resistant layer.

[0032] Example 5: The embodiment provides a preparation method of the armored and corrosion- integrated corrosion-resistant energy storage system power cable integrated functional layer, compared with example 1, the difference lies in adjusting the ratio of functional fillers in the integrated material, as follows: 78 parts of epoxy modified polyolefin, 3.8 parts of isocyanate curing agent, 3.5 parts of nano zinc oxide, 6 parts of chopped glass fiber, 0.15 parts of calcium stearate, 0.7 parts of photoinitiator and 2.3 parts of compatibilizer are weighed, and the raw material drying and subsequent mixing and curing steps are completed according to the conditions of example 1; the purpose is to verify the strengthening effect of the ratio of corrosion-dominant fillers on the corrosion resistance of the cable.

[0033] Example 6: The embodiment provides a preparation method of the armored and corrosion- integrated corrosion-resistant energy storage system power cable integrated functional layer, compared with example 1, the difference lies in adjusting the amount of isocyanate curing agent in the integrated material, as follows: 78 parts of epoxy modified polyolefin, 4.1 parts of isocyanate curing agent, 3.0 parts of nano zinc oxide, 6.5 parts of chopped glass fiber, 0.15 parts of calcium stearate, 0.7 parts of photoinitiator and 2.3 parts of compatibilizer are weighed, and the raw material drying and subsequent mixing and curing steps are completed according to the conditions of example 1; the purpose is to verify the influence of high curing agent dosage on the crosslinking density, structural stability and anti-deformation ability of the composite material.

[0034] Example 7: This example provides a preparation method of the armored and corrosion integrated functional layer of the corrosion-resistant power cable for energy storage system, compared with example 1, the difference lies in adjusting the process parameters of integrated co-extrusion, as follows: using a three-layer concentric die double screw co-extrusion machine, a flow guide ring is arranged in the die, the screw speed is set to 70 r / min, the barrel temperature is set to 145℃, 165℃ and 175℃ in three zones, and the die temperature is 160℃; the preheated armored substrate is continuously sent from the center channel of the co-extrusion machine, and the integrated composite layer base material is injected from the side feeding port, and the integrated structure with a thickness of 2.0 mm is formed by synchronous coating; the purpose is to verify the influence of lower die temperature and higher screw speed on the uniformity of integrated structure coating and the adhesion between layers.

[0035] Example 8: This example provides a preparation method of the armored and corrosion integrated functional layer of the corrosion-resistant power cable for energy storage system, compared with example 1, the difference lies in adjusting the curing process parameters, as follows: the integrated structure of co-extrusion is sent into the ultraviolet curing oven, the ultraviolet light wavelength is set to 265 nm, the irradiation intensity is 13.5 mW / cm 2 , and the irradiation time is 4 min; the integrated structure after ultraviolet curing is transferred to the hot air oven, the temperature is set to 130℃, and the heat preservation time is 20 min; the purpose is to verify the influence of strengthening ultraviolet curing and shortening the heat curing time on the surface integrity, curing efficiency and deep layer adhesion of the integrated structure.

[0036] Comparative Example 1: This comparative example uses the existing traditional layered preparation process of armored first and then corrosion resistant, which specifically includes the following steps: selecting the same low carbon steel strip as example 1, only sandblasting and degreasing treatment, no chemical activity modification step; using conventional polyethylene (PE) as the corrosion resistant coating material, coating PE coating on the surface of the armored layer by single screw extrusion coating machine, thickness 2.0 mm, extrusion coating temperature 165℃; only using 130℃ heat curing for 30 min, without ultraviolet curing step, the subsequent wet grinding and drying process is consistent with example 1.

[0037] Comparative Example 2: This comparative example cancels the chemical activity modification step of the substrate surface, only mechanical sandblasting and degreasing treatment, and directly uses the degreased substrate for subsequent co-extrusion, the rest of the steps and parameters are consistent with example 1, which aims to verify the necessity of chemical modification step for the formation of interface chemical bonding and bonding stability.

[0038] Comparative Example 3: This comparative example cancels the UV curing step, and uses a single thermal curing process. The integrative structure formed by co-extrusion is directly transferred to a hot air oven, with a temperature setting of 130°C, and a holding time of 30 min. After that, wet grinding and drying are completed according to the conditions of Example 1. The remaining steps and parameters are the same as those of Example 1. The purpose is to verify the advantages of gradient curing process over traditional single thermal curing in terms of surface integrity and deep curing effect.

[0039] Comparative Example 4: This comparative example removes nano zinc oxide from the integrative material and reduces the amount of chopped glass fiber. The remaining steps and parameters are the same as those of Example 1, as follows: 78 parts of epoxy modified polyolefin, 3.8 parts of isocyanate curing agent, 5 parts of chopped glass fiber, 0.15 parts of calcium stearate, 0.7 parts of photoinitiator, and 2.3 parts of compatibilizer are weighed. The raw material drying and subsequent mixing and curing steps are completed according to the conditions of Example 1. The purpose is to verify the synergistic effect of nano zinc oxide and chopped glass fiber on the improvement of cable corrosion resistance and mechanical strength.

[0040] To verify the core performance of the integrative functional layer, the integrative functional layers prepared in Examples 1-8 and Comparative Examples 1-4 are taken as test objects. Systematic tests are carried out around the interfacial peeling strength, salt spray corrosion resistance time, tensile strength, surface cracking rate and structural compactness. The specific test scheme is as follows.

[0041] In the interfacial peeling strength test, reference is made to GB / T2790-1995 "Adhesives 180° Peeling Strength Test Method", 180° peeling method is adopted, test rate is 50 mm / min, test environment temperature is 25℃±2℃, test sample width is 25 mm, and it is ensured that the peeling process is smooth and continuous; in the salt spray corrosion resistance time test, reference is made to GB / T10125-2021 "Salt Spray Test for Artificial Atmosphere Corrosion Test", neutral salt spray test is adopted, salt solution is 5wt% sodium chloride aqueous solution, solution pH value is 7, test temperature is 35℃±2℃, continuous spraying mode, and timing is stopped until obvious rust appears on the surface of the sample; in the tensile strength test, reference is made to GB / T1040.3-2006 "Determination of Tensile Properties of Plastics Part 3: Test Conditions for Films and Sheeting", tensile rate is 5 mm / min, test environment temperature is 25℃, test sample adopts dumbbell type I sample, gauge length is 50 mm, sample width is 10 mm, and thickness is 2.0 mm; in the surface cracking rate test, reference is made to GB / T1766-2008 "Rating Method for Aging of Color Paint and Varnish Coating", first, the sample is subjected to-40℃-125℃ temperature difference cycle treatment, single cycle period is 8h, and cumulative cycle is 1000 times; after the cycle is completed, visual rating method is combined with image analysis to calculate the percentage of sample surface cracking area to total surface area; in the structure compactness test, reference is made to GB / T1034-2008 "Determination of Water Absorption of Plastics" and scanning electron microscope observation method, the sample is soaked in 25℃ deionized water for 24h, mass change rate before and after soaking is calculated, cross section of the sample is observed by electron microscope, magnification is 1000 times, and the percentage of cross section pore area to total area of observation area is calculated.

[0042] Specific test results are shown in Table 1:

[0043]

[0044] According to the data in Table 1, the cross-section peel strength of Examples 1-8 is between 1.1 MPa and 1.5 MPa, and the overall level is kept high, among which the interface peel strength of Example 3 is the highest, reaching 1.5 MPa, and the interface peel strength of Example 4 is the lowest, being 1.1 MPa, and the interface peel strength of Comparative Examples 1-4 is between 0.5 MPa and 1.3 MPa, which is lower than that of most examples; the interface peel strength of Example 3 is optimal, because the amount of KH-550 is increased and the pH value of the treatment solution is improved, so that more amino active groups are introduced on the surface of the substrate, and chemical bonding reaction occurs between the amino active groups and the epoxy groups of the epoxy-modified polyolefin in the integrated material, and the physical anchoring effect of the micro-nano aluminum oxide particles is further enhanced, so that the interface bonding is more firm; the interface peel strength of Example 4 is relatively low, because the amount of the epoxy-modified polyolefin is reduced, resulting in a decrease in the density of the interface reaction sites and a weakening of the chemical bonding effect; the interface peel strength of Comparative Example 2 is the lowest, being only 0.5 MPa, and the core reason is that the surface chemical modification step of the substrate is missing, and the combination is only achieved by the physical structure formed by mechanical sand blasting, without forming stable chemical bonding, and the interface bonding force only depends on the van der Waals force, which is much lower than the synergistic effect of chemical bonding and physical anchoring of the examples; Comparative Example 1 uses the traditional layered process without chemical modification treatment, and the interface bonding force is weak, and the peel strength is only 0.7 MPa, which further proves the key role of the surface double activation treatment and the integrated co-extrusion process in the present application in improving the interface bonding force.

[0045] The salt spray resistance time of Examples 1-8 is in the range of 1400 h-1600 h, among which Example 5 performs best, with a salt spray resistance time of 1600 h, and Example 4 is relatively low, with a salt spray resistance time of 1400 h; the salt spray resistance time of the comparative examples is concentrated in the range of 800 h-1400 h, with Comparative Example 2 being the lowest at 800 h, and Comparative Examples 1 and 4 being 900 h; Example 5 has outstanding salt spray resistance performance, which is due to the increased amount of nano zinc oxide, which can effectively adsorb harmful ions such as chloride ions in the salt spray through ion exchange, blocking the penetration path of the corrosion medium to the substrate, and at the same time, uniformly dispersing in the integrated material to form a dense corrosion protection barrier; Example 4 has a relatively short salt spray resistance time, which is related to the reduced amount of epoxy-modified polyolefin, and the insufficient support of the corrosion-resistant base material leads to a decrease in the density of the corrosion-resistant layer, making it easier for the corrosion medium to penetrate; the salt spray resistance time of Comparative Example 4 is only 900 h, because it lacks the adsorption effect of nano zinc oxide on corrosion ions, and the corrosion resistance is greatly weakened; Comparative Example 1, as the prior art, uses a conventional PE corrosion-resistant layer, and the interface between the corrosion-resistant layer and the armored layer is prone to gaps, so that the corrosion medium can quickly penetrate through the gaps to the surface of the armored layer, resulting in a salt spray resistance time of only 900 h, which is much lower than the corrosion resistance of the examples, fully demonstrating the significant advantages of the integrated composite material and the interface modification process of the present application in improving the corrosion resistance.

[0046] The tensile strength of examples 1-8 is between 500 MPa and 530 MPa, the highest tensile strength of example 6 is 530 MPa, and the lowest tensile strength of example 4 is 500 MPa; the tensile strength of the comparative examples is between 460 MPa and 500 MPa, the lowest tensile strength of comparative example 1 is 460 MPa, and the tensile strength of comparative example 3 is 500 MPa, which is the same as that of example 4; the tensile strength of example 6 is the highest, which is attributed to the increase of the amount of isocyanate curing agent, more curing agent promotes the formation of a more dense crosslinking network of the epoxy modified polyolefin molecular chain, and the reinforcing effect of the short glass fiber is fully played, so that the overall mechanical properties of the integrated functional layer are improved; the tensile strength of example 4 is relatively low, which is due to the decrease of the amount of epoxy modified polyolefin, so that the interface bonding sites of the substrate and the integrated material are insufficient, and local stress concentration is easy to occur when stressed, resulting in the decrease of the overall tensile strength; the tensile strength of comparative example 1 is the lowest, which adopts a traditional layered structure, the interface bonding between the armor layer and the corrosion protection layer is weak, and interlayer slip is easy to occur during the stretching process, so that effective mechanical synergy cannot be formed, thereby resulting in the low tensile strength; the tensile strength of comparative example 3 is 500 MPa, which is higher than that of comparative examples 1 and 4, but lower than that of most examples, which is mainly due to the use of a single thermal curing process, the crosslinking uniformity of the integrated material is insufficient, and there is a difference in the curing degree between the surface layer and the deep layer, which affects the overall mechanical properties.

[0047] The surface cracking rate of examples 1-8 is controlled between 0.6% and 1.0%, the lowest surface cracking rate of example 8 is 0.6%, and the highest surface cracking rate of example 4 is 1.0%; the surface cracking rate of the comparative examples is between 1.2% and 4.0%, the highest surface cracking rate of comparative example 1 is 4.0%, and the lowest surface cracking rate of comparative example 4 is 1.2%; the surface cracking rate of example 8 is the lowest, which is due to the strengthening of the ultraviolet curing intensity and the appropriate shortening of the thermal curing time, the surface layer is quickly cured and shaped by ultraviolet light, which effectively avoids the shrinkage cracking problem of the surface layer in the deep thermal curing process, and sufficient thermal curing time ensures that the deep crosslinking reaction is sufficient, so that the integrated structure can better resist the action of thermal stress in the temperature difference cycle process; the surface cracking rate of example 4 is relatively high, which is related to the insufficient structural support caused by the decrease of the amount of epoxy modified polyolefin, and the thermal stress generated by the temperature difference cycle is easy to cause micro cracking at the weak structure; the surface cracking rate of comparative example 1 is the highest, which is only treated by a single thermal curing process, the interface bonding between the corrosion protection layer and the armor layer is not firm, and the periodic tensile and shear stress generated by the difference in the thermal expansion coefficient between the layers directly leads to interface peeling and surface cracking during the severe temperature difference cycle; the surface cracking rate of comparative example 3 is 3.5%, which is lower than that of comparative example 1, but much higher than that of the examples, which lacks the ultraviolet curing step, the surface layer is not cured in time, and the surface layer is easy to produce shrinkage stress during the thermal curing process, and the cracking phenomenon is more obvious after the temperature difference cycle.

[0048] The water absorption of examples 1-8 is less than 0.05wt%, and the cross-section porosity is less than 0.8%; wherein the water absorption of example 5 is the lowest, which is 0.02wt%, and the cross-section porosity of example 6 is the lowest, which is 0.4%; the water absorption of the comparative examples is between 0.05wt%-0.12wt%, and the cross-section porosity is between 1.2%-2.5%, the water absorption and cross-section porosity of comparative example 1 are the highest, which are 0.12wt% and 2.5% respectively; the water absorption of example 5 is the lowest, more nano zinc oxide is uniformly dispersed in the integrated material, filling the small voids inside the material, and forming a good interface with the epoxy modified polyolefin, effectively blocking the water penetration path, the cross-section porosity of example 6 is the lowest, because the increase of the amount of curing agent promotes the cross-linking of the molecular chain of the integrated material, forming a more dense structure, reducing the generation of internal pores; the structure of comparative example 1 is the worst, there is an obvious interface gap between the armored layer and the corrosion prevention layer, and the cross-linking degree of the PE corrosion prevention layer itself is low, so there are more internal pores, resulting in a significantly high water absorption and porosity, the water absorption and porosity of comparative example 2 are 0.08wt% and 1.8% respectively, which are higher than those of the examples, because it lacks the chemical modification step, the interface between the substrate and the integrated material is not tightly combined, small gaps are easily formed, water is easily penetrated, and the structure porosity increases.

[0049] The application also provides a preparation method of the armored and corrosion-preventing integrated corrosion-resistant energy storage system power cable, which specifically comprises the following steps: S1: selecting a high-conductivity copper rod or aluminum rod, and preparing a conductor layer through wire drawing and bundle twisting processes; S2: using a three-layer co-extrusion process to successively and continuously extrude a conductor shielding layer, an insulation layer and an insulation shielding layer outside the conductor, controlling the extrusion temperature to be 130-145 DEG C, ensuring that the thicknesses of the layers are uniform and the interfaces are tightly attached, and cooling and shaping after cross-linking treatment; S3: extruding a high-density polyethylene inner sheath layer outside the insulation shielding layer using a single-screw extruder, controlling the extrusion temperature to be 165-175 DEG C, and controlling the thickness to be 1.5-2.0 mm, and reserving after cooling; S4: preheating the surface of the inner sheath layer to 120-125 DEG C, uniformly coating an EVA hot melt adhesive layer, and then bonding the integrated functional layer to the inner sheath layer through a hot press roller, setting the temperature to be 145 DEG C, the pressure to be 0.25 MPa, and the holding time to be 12 min, so as to realize tight bonding between the layers; and S5: extruding a flame-retardant polyethylene outer sheath layer outside the integrated functional layer, controlling the extrusion temperature to be 165-175 DEG C, and controlling the thickness to be 2.0-2.5 mm, and cooling and shaping in a water cooling tank after extrusion, so as to obtain a finished cable.

[0050] To verify the core performance of the whole cable, the integrated functional layer prepared by Examples 1-8 and Comparative Examples 1-4 was used in the preparation of the whole cable, and systematic tests were carried out on the temperature difference cycle resistance of the whole cable, the insulation resistance change rate, the mechanical protection performance and the flame retardant performance. The specific test scheme is as follows: in the temperature difference cycle resistance test of the whole cable, referring to GB / T2951.41-2018 "Cable and optical cable insulation and sheath materials General test methods Part 41: Environmental stress cracking resistance test" and GB / T2951.31-2008 "Cable and optical cable insulation and sheath materials General test methods Part 31: High temperature aging test method", -40℃-125℃ temperature difference cycle treatment was adopted, the single cycle period was 8h, and the cumulative cycle was 1500 times. After the cycle was completed, whether the whole cable appeared cracking, interlayer peeling phenomenon was observed, and the interface peeling strength retention rate was tested; in the insulation resistance change rate test, the test environment temperature was controlled at 25℃±2℃, and the relative humidity was 60%±5%. The initial value of the insulation resistance of the whole cable was measured by 1000VDC megohmmeter; after 1500 times of temperature difference cycle and 1500h of salt spray corrosion, the insulation resistance was measured again, and the resistance change rate was calculated; in the mechanical protection performance test, a 1kg weight was used to impact the whole cable sample from a height of 1m, the impact point spacing was 50mm, and whether the sample appeared damage, insulation layer breakdown phenomenon was observed; under the environment of 25℃, 1000N pressure was applied to the whole cable for 1min, and after release, whether the whole cable appeared permanent deformation, interlayer separation was observed; in the flame retardant performance test, referring to GB / T18380.12-2008 "Cable and optical cable combustion test under flame conditions Part 12: Single insulated wire and cable flame vertical spread test 1kW premixed flame test method", 1kW premixed flame was used to vertically burn the whole cable sample, the burning time was 60s, and after extinguishing, the afterburning time, afterglow time of the sample was observed, and the carbonization length was measured.

[0051] The specific test results are shown in Table 2:

[0052]

[0053] According to the data in Table 2, the temperature difference cycle performance of the whole cable of Examples 1-8 is excellent, except that the first peeling cycle of Example 4 is 950 times, the rest of the examples can withstand 1000 times of temperature difference cycle without interface peeling phenomenon, and the temperature difference cycle performance of the comparative examples is significantly deteriorated. The peeling occurs after 400 cycles of Comparative Example 1 and 550 cycles of Comparative Example 2; Example 3 can resist interlayer thermal stress in temperature difference cycle due to the strongest interfacial bonding force of the integrated functional layer, and no peeling occurs. Example 4 has insufficient bonding sites between the integrated functional layer and the inner sheath layer due to the reduced amount of epoxy modified polyolefin, and peeling occurs under the action of thermal stress. Comparative Example 1 uses a traditional layered process, and the interlayer is only combined by van der Waals force. The thermal expansion and contraction difference in temperature difference cycle leads to stress concentration between the layers, and peeling occurs quickly. Comparative Example 2 lacks a chemical modification step, and the interfacial bonding force is weak, so the temperature difference cycle resistance is greatly reduced.

[0054] The insulation resistance change rate of Examples 1-8 is controlled between 2.5%-4.5%, and the lowest is 2.5% of Example 5 and the highest is 4.5% of Example 4. The insulation resistance change rate of the comparative examples is between 5.2%-12.5%, and the highest is 12.5% of Comparative Example 1. Example 5 has the lowest resistance change rate because the integrated functional layer has the best corrosion resistance, and no corrosion medium penetrates after salt spray corrosion, and the insulation layer is not contaminated. Example 4 has a slight decrease in insulation resistance due to the insufficient density of the corrosion-resistant layer, and a small amount of corrosion medium penetrates. Comparative Example 1 is easily formed with a gap between the layers, and the corrosion medium quickly penetrates to destroy the insulation layer, so the resistance change rate is significantly high. Comparative Example 4 lacks nano zinc oxide, and the corrosion resistance is weakened, so the insulation layer is affected by corrosion, and the resistance change rate reaches 10.5%.

[0055] The mechanical protection performance of Examples 1-8 is good, and except for the slight deformation of Example 4 after crushing, the rest of the examples have no damage and no deformation after impact and crushing. Comparative Example 1 is damaged after impact and severely deformed after crushing, and Comparative Example 4 is damaged after impact and significantly deformed after crushing. Example 6 has the highest tensile strength of the integrated functional layer, and the mechanical support capability is strong, which can effectively resist impact and crushing stress. Example 4 has a slight decrease in mechanical properties of the integrated functional layer, and slight deformation occurs after crushing. Comparative Example 1 uses a traditional layered structure, and the interlayer bonding is weak, which cannot withstand mechanical stress, resulting in damage and severe deformation. Comparative Example 4 has insufficient mechanical enhancement due to the reduced amount of short glass fibers, and the mechanical protection performance is deteriorated.

[0056] The flame-retardant performance of examples 1-8 all meet the qualified standard, the afterflame time is ≤10s, the afterglow time is ≤20s, example 8 performs best, the afterflame time is 6s, the afterglow time is 12s, the flame-retardant performance of the comparative examples all does not meet the qualified standard, the afterflame time is ≥18s, the afterglow time is ≥28s, the afterflame time of comparative example 1 is 25s, the afterglow time is 40s; example 8 can effectively block the flame spread due to the compact structure of the integrated functional layer and the synergistic effect with the outer sheath layer, the flame-retardant synergistic effect of example 4 slightly decreases due to the insufficient compactness of the integrated functional layer, but still meets the standard, the flame channel is easily formed between the layers of comparative example 1, the flame-retardant effect is poor, the material structure of comparative example 4 is loose, the flame is easily penetrated, and the flame-retardant performance is significantly deteriorated.

[0057] The technical scope of the present application is not limited to the content in the above description, and those skilled in the art can make various modifications and changes to the above examples without departing from the technical idea of the present application, and these modifications and changes should all belong to the protection scope of the present application.

Claims

1. A kind of armored and integrated with corrosion-resistant energy storage system power cable for corrosion-resistant, by inside to outside, it includes conductor layer, conductor shield layer, insulation layer, insulation shield layer, inner sheath layer and outer sheath layer in order;Its characterized in that, The inner sheath layer and the outer sheath layer are provided with an integrated functional layer, the integrated functional layer has mechanical support protection and corrosion barrier function, the integrated functional layer is composed of an armored substrate which is mechanically micro-nano structured and chemically modified, and an integrated material which is tightly covered on the surface of the modified armored substrate, the armored substrate is obtained by sequentially performing the following treatments, first, mechanical sand blasting treatment is performed to make the surface roughness Ra reach 1.8-2.0 μm; then, chemical modification treatment is performed, the armored substrate is immersed in a treatment liquid containing silane coupling agent KH-550 and micro-nano aluminum oxide particles to introduce amino active groups on the surface and form physical anchoring structure; the integrated material is composed of the following components by weight parts: 75-80 parts of epoxy modified polyolefin, 3.5-4.1 parts of isocyanate curing agent, 0.6-0.8 parts of photoinitiator, 2.5-3.5 parts of nano zinc oxide, 6-7 parts of chopped glass fiber, 0.12-0.18 parts of calcium stearate, 2.2-2.5 parts of compatibilizer PE-g-MAH; the gradient curing process is ultraviolet curing and thermal curing which are sequentially performed.

2. The armored and corrosion-protected integrated corrosion-resistant energy storage system power cable of claim 1, wherein: The thickness of the integrated functional layer is 1.8-2.2 mm.

3. The armored and corrosion-integrated corrosion-resistant power cable for energy storage system according to claim 1, characterized in that: The mechanical sand blasting treatment is performed by using white corundum sand with a particle size of 0.22 mm, the sand blasting pressure is 0.35-0.4 MPa, and the treatment time is 4.2-4.5 min.

4. The armored and corrosion-integrated corrosion-resistant power cable for energy storage system according to claim 1, characterized in that: The treatment liquid material includes 1.8-2.2 parts of silane coupling agent KH-550, 0.5-0.9 parts of micro-nano aluminum oxide particles, 96.5-97.7 parts of ethanol-water solution, and 0.04-0.06 parts of glacial acetic acid by weight parts; the volume ratio of ethanol to water in the ethanol-water solution is 3:

7.

5. The armored and corrosion-integrated corrosion-resistant power cable for energy storage system according to claim 1, characterized in that: The epoxy group content in the epoxy modified polyolefin is 7-8 wt%, the water content is ≤0.05 wt%; the water content of the isocyanate curing agent is ≤0.02 wt%; the water content of the photoinitiator is ≤0.03 wt%; the particle size of the nano zinc oxide is 40-50 nm, and the water content is ≤0.1 wt%; the length of the chopped glass fiber is 0.3-0.4 mm, and the water content is ≤0.1 wt%; the water content of the calcium stearate and the compatibilizer PE-g-MAH is all ≤0.05 wt%.

6. The armored and corrosion-integrated corrosion-resistant power cable for energy storage system according to claim 1, characterized in that: The preparation steps of the integrated functional layer include: S1: first, the surface of the armored substrate is mechanically micro-nano structured, then it is soaked in sodium hydroxide aqueous solution for degreasing, and finally the armored substrate is immersed in a treatment liquid for chemical activation modification to obtain a modified substrate which is dried for standby; S2: first, the raw materials of the integrated material are dried and pretreated respectively, then the epoxy modified polyolefin is premixed with the compatibilizer, the functional fillers are dispersed, the curing agent and the photoinitiator are added and mixed at low speed after cooling to obtain an integrated composite layer base material; S3: the preheated modified substrate is sent into the center channel of the co-extrusion machine, the integrated composite layer base material is injected from the side feeding port, and the integrated structure is formed by synchronous coating; S4: the integrated structure is gradient cured, and then it is wet ground, washed, and dried to obtain the integrated functional layer.

7. The armored and corrosion-integrated corrosion-resistant power cable for energy storage system according to claim 1, characterized in that: In the co-extrusion process, the screw rotation speed of the co-extrusion machine is 65-70 r / min, the barrel temperature is 140-150℃ in the first zone, 160-170℃ in the second zone, and 170-180℃ in the third zone, and the die temperature is 160-165℃; the armored base material is preheated to 125-135℃ before co-extrusion, and is kept for 30-40 min.

8. The armored and corrosion-integrated corrosion-resistant power cable for energy storage system according to claim 1, characterized in that: The UV-curing UV light wavelength is 265 nm, the irradiation intensity is 12.5-13.5 mW / cm 2 , and the irradiation time is 4 min; the heat-curing temperature is 130℃, and the holding time is 20-25 min.

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