A flexible cable for energy storage battery and its production process

Abstract

The present invention provides a flexible cable for energy storage batteries and its production process, the cable includes a main wire core, a power storage wire core, and a cable outer sheath; wherein the main wire core and the power storage wire core are arranged side by side; the cable outer sheath is arranged outside the main wire core and the power storage wire core; the power storage wire core is composed of a plurality of wire cores twisted together and then wrapped with non-woven fabric; each of the wire cores is composed of a power storage conductor, a graphene fiber layer, a metal composite layer, a power storage protective layer, and a power storage outer sheath from the inside to the outside. The structural design and material selection of the present invention fully meet the battery acid resistance, aging resistance, weather resistance, moisture resistance, and UV resistance of the cable for the energy storage battery system, and has outstanding characteristics such as high life, high insulation, and softness. Under certain circumstances, it can be used as an energy storage device to store a small amount of electrical energy for use in instrument control circuits.

Description

Technical Field

[0001] The invention relates to a cable for an energy storage system, in particular to a soft cable for an energy storage battery and a production process thereof. Background Art

[0002] Currently, there are three major application areas in the energy storage battery market: power energy storage, household energy storage, and base station energy storage. Among them, the backup power supply field of communication base stations currently accounts for a large proportion, accounting for nearly half of the entire energy storage battery market.

[0003] Thanks to the "energy home" wave started by Tesla, home energy storage has a large room for further development and expansion, but it is currently mainly concentrated in overseas regions such as the United States, Germany, Australia and Japan. It is still in its early stages of development in China and the market size is relatively small. However, in the long run, its development prospects cannot be underestimated.

[0004] Data released by the National Energy Administration show that in the period of 2017-2020, the scale of new construction of distributed photovoltaic power generation totaled 86.5GW, with 8GW of leading base projects arranged each year. During the same period, the scale of new construction of wind power generation totaled 110.41GW. In addition, by 2020, the installed capacity of solar power generation is expected to reach 160 million kilowatts.

[0005] Overall, the current growth rate of the domestic energy storage battery market is still quite obvious. According to statistics, as of the first half of 2017, my country's planned energy storage projects have an installed capacity of about 1,100 megawatts, which does not include pumped storage power stations and heat storage projects.

[0006] As a supporting product for energy storage batteries, energy storage battery cables have very high requirements due to the special use environment of energy storage battery systems. Energy storage battery cables must not only have excellent insulation electrical properties and mechanical properties, but also have battery acid resistance, aging resistance, sunlight resistance, low smoke and halogen-free flame retardancy, and environmental protection. Summary of the invention

[0007] The purpose of the present invention is to provide a flexible cable for an energy storage battery system and a production process thereof, which can be used as an energy storage device to store a small amount of electric energy for use by an instrument control circuit under specific circumstances.

[0008] The technical solution for achieving the purpose of the present invention is:

[0009] A flexible cable for energy storage batteries, comprising: a main core, an energy storage core, and an outer cable sheath; wherein the main core and the energy storage core are arranged side by side; the outer cable sheath is arranged outside the main core and the energy storage core; the energy storage core is composed of a plurality of cores twisted together and then wrapped with non-woven fabric; each of the cores is composed of an energy storage conductor, a graphene fiber layer, a metal composite layer, an energy storage protective layer, and an outer energy storage sheath from the inside to the outside. The present invention uses a special energy storage core, the conductor of which is wrapped with graphene fiber and then with a metal composite layer of a metal composite film. The graphene fiber has a strong charge adsorption property, which enables the cable to have a certain energy storage capacity. Then, the irradiated cross-linked low-smoke halogen-free flame-retardant TPE material of the same material as the main core plays a protective role, and at the same time, multiple cores are twisted into regular cables to improve the charge storage capacity.

[0010] Furthermore, the main line core is a single-core structure, which includes, from inside to outside, a main conductor, a conductive adhesive layer, an insulating layer, an insulating protective layer, an outer sheath layer and an outer sheath protective layer.

[0011] Furthermore, the main conductor adopts Class 6 copper conductor or tin-copper conductor, the diameter of the single wire is 0.08mm-0.12mm, multiple single wires are bundled in the same direction and then layered and re-twisted, the conductive adhesive layer is extruded on the outside of the main conductor, and the conductive adhesive fills the gap of the main conductor. The main wire core of the present invention adopts bundle twisting in the same direction and layered and re-twisted multiple strands of fine wires, which greatly improves the flexibility of the cable. At the same time, the gap of the conductor is filled with high-temperature resistant conductive adhesive to improve the conductivity of the conductor, enhance the roundness of the conductor, and reduce the contact resistance of the conductor installed on the terminal.

[0012] Furthermore, the insulating layer is irradiated cross-linked polyethylene; the insulating protective layer is fluorinated modified silicone resin. With such a structure, the temperature resistance level reaches (90-125)°C, and the insulating layer is protected by statically coated silicone resin material, which ensures the high insulation performance of the cable while taking into account the low smoke and halogen-free, wear-resistant characteristics and service life of the cable.

[0013] Furthermore, the outer sheath layer is a radiation cross-linked low-smoke halogen-free flame-retardant TPE; the outer sheath protective layer is a polyether polyurethane (such as a polyether polyurethane coating). This not only protects the printing and appearance, but also prevents moisture in the air from penetrating into the outer sheath layer, enhancing the cable's resistance to sunlight and aging.

[0014] Furthermore, the electricity storage conductor is a solid copper conductor with a diameter of 0.5 mm to 0.8 mm.

[0015] Furthermore, the metal composite layer adopts a copper-plastic composite film, and the plastic layer is bonded to the graphene fiber layer.

[0016] Furthermore, the power storage outer sheath and the cable outer sheath are formed by extrusion of radiation cross-linked low-smoke halogen-free flame-retardant TPE material, and the Shore A hardness of the material is 50-60.

[0017] The present invention also provides a production process for a flexible cable for an energy storage battery, which adopts the above-mentioned flexible cable structure for an energy storage battery; wherein the cable outer sheath is extruded by an ∞-shaped die. The ∞-shaped die can extrude an outer sheath of the same material outside the main line core and the energy storage line core, fix the main line core and the energy storage line core, and facilitate laying and installation.

[0018] Furthermore, the insulating protective layer and the outer sheath protective layer are formed by static coating process.

[0019] The present invention has positive effects:

[0020] (1) The structural design and material selection of the present invention fully meet the battery acid resistance, aging resistance, weather resistance, moisture resistance, and UV resistance of the cable used in the energy storage battery system, and have outstanding characteristics such as long life, high insulation, and softness. Under certain circumstances, it can be used as an energy storage device to store a small amount of electrical energy for use in instrument control circuits.

[0021] (2) The main conductor of the present invention adopts a structure of co-directional bundle twisting and layered multiple twisting, which greatly improves the flexibility of the cable and facilitates installation.

[0022] (3) The conductive adhesive layer of the present invention is formed by extruding a high temperature resistant conductive adhesive and filling the gaps between the main conductors with the conductive adhesive, thereby increasing the conductivity of the conductors and ensuring the roundness of the conductors.

[0023] (4) The present invention adopts statically coated silicone resin material as the insulating protective layer, which ensures the high insulation performance of the cable while taking into account the low-smoke, halogen-free and wear-resistant characteristics of the cable.

[0024] (5) The outer sheath of the present invention adopts radiation cross-linked TPE material, and the outer sheath protective layer adopts static coating polyether polyurethane coating, which can protect the printing and appearance while also preventing moisture in the air from penetrating into the outer sheath layer, thereby enhancing the cable's resistance to sunlight and aging.

[0025] (6) The graphene fiber layer of the present invention is a graphene fiber material with strong polarity, which greatly improves the charge storage capacity.

[0026] (7) The present invention uses a graphene fiber layer wrapped around the conductor, and then uses a metal composite layer to cover the graphene fiber outer sheath. Finally, the outer sheath uses the same radiation cross-linked low-smoke halogen-free flame-retardant TPE material as the outer sheath of the main line core to play a protective role. At the same time, multiple cores are twisted together using regular cabling to improve the ability to store charge.

[0027] (8) The outer sheath extruded by the "∞" die of the present invention is a radiation cross-linked low-smoke halogen-free flame-retardant TPE material, which is used to fix and protect the main line core and the storage line core, and is easy to lay and install. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0029] Figure 1 It is a structural schematic diagram of the present invention.

[0030] The figures are:

[0031] 1 main line core, 11 main conductor, 12 conductive adhesive layer, 13 insulating layer, 14 insulating protective layer, 15 outer sheath layer, 16 outer sheath protective layer, 2 storage line core, 21 storage conductor, 22 graphene fiber layer, 23 metal composite layer, 24 storage protective layer, 25 non-woven fabric, 3 cable outer sheath. DETAILED DESCRIPTION

[0032] (Example 1)

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The technical solution of the present invention is described and explained in detail below through several specific embodiments.

[0036] (Example 1)

[0037] See Figure 1 , a flexible cable for an energy storage battery in this embodiment includes:

[0038] Main wire core 1, wire storage core 2, cable outer sheath 3; wherein, main wire core 1 comprises main conductor 11 and conductive adhesive layer 12, insulating layer 13, insulating protective layer 14, outer sheath layer 15, outer sheath protective layer 16 arranged on the outside of said main conductor 11 in sequence; said wire storage core 2 adopts 1+6 structure and is equally arranged and twisted into cable; said cable outer sheath 3 is arranged on the outside of main wire core 1 and wire storage core 2 through "∞" mold. It is used to protect and fix the main wire core and wire storage core, and is convenient for laying and installation.

[0039] Specifically, the main conductor 11 is a Class 6 copper conductor or a tinned copper conductor, and is formed by a plurality of single filaments with a diameter of 0.08 mm to 0.12 mm being bundled in the same direction and then layered and re-twisted. The bundled wires are formed by a plurality of filaments being twisted in the left direction, and the twisted pitch-diameter ratio is 18-20 times. The strands are re-twisted by regular twisting, and the twisted pitch-diameter ratio is 14-16 times. The twisting direction is left-handed, and the finished conductor is left-handedly twisted, and the twisted pitch-diameter ratio is 12-14 times. The twisted single filaments should not be too thin or too thick. 0.08-0.12 mm single filaments are the best solution, which can ensure that the conductor is not easily broken while improving the flexibility of the conductor. The inner and outer sides of the twisted pitch-diameter ratio need to be reasonably configured. The size of the pitch-diameter ratio affects the flexibility and resistance of the conductor. If the inner and outer layer pitch-diameter ratios are not properly matched, the twisting process will produce a "lantern" shape, the conductor will become hard, and the conductor will be scattered, which seriously affects the quality of the cable. The twisted pitch ratio selected in this embodiment greatly improves the flexibility of the cable and facilitates installation; the gaps between the main conductors 11 are filled with conductive glue, and a conductive glue layer 12 made of high-temperature resistant conductive glue is extruded on the outside with a thickness of 0.1mm-0.2mm. This thickness can fill the gaps between the conductors and cover the surface of the conductors. Through resistance test comparison, it is found that the (0.1-0.2)mm conductor has the best resistance and the best appearance roundness, which increases the conductivity of the conductor and also ensures the roundness of the conductor; then, an insulating layer 13 made of irradiated cross-linked polyethylene is extruded on the outside of the conductive glue layer 12, and the temperature resistance grade reaches 90-125°C; then, an insulating protective layer 14 made of fluorinated modified silicone resin is statically coated on the outside of the insulating layer 13, with a thickness of 0.05mm-0. 1mm, fluorinated modified silicone resin is a liquid material. The electrostatic coating process can improve the wear resistance and insulation resistance of the wire core. The thickness should not be too thick, which will affect the outer diameter of the wire core. The thicker the thickness, the more difficult the static coating process. The thickness of this embodiment can ensure the high insulation performance of the cable while taking into account the low-smoke, halogen-free and wear-resistant characteristics of the cable; then a layer of outer sheath layer 15 made of radiation cross-linked low-smoke, halogen-free and flame-retardant TPE is extruded on the outside of the insulating protective layer 14, and the Shore A hardness of the material is 50-60, and then a layer of outer sheath protective layer 16 made of polyether polyurethane coating is statically coated on the outside of the outer sheath protective layer 15, with a thickness of 0.05mm-0.1mm, which can protect the printing and appearance while also preventing moisture in the air from penetrating into the outer sheath layer 15, thereby enhancing the cable's resistance to sunlight and aging.

[0040] Specifically, the power storage wire core 2 uses a solid copper conductor with a diameter of 0.5mm to 0.8mm as the power storage conductor 21. The selection of the outer diameter takes into account the overall softness. The solid conductor is used instead of the soft structure conductor to prevent the surface twist of the soft structure conductor from affecting the graphene fiber layer and reducing the power storage capacity. A graphene fiber layer 22 made of graphene fiber material with strong polarity is wrapped on the outside, and then a metal composite layer 23 made of copper-plastic composite film material is wrapped. During the coating, the plastic layer is attached to the graphene fiber layer 22, and then a layer of material is extruded, which is a power storage protection layer 24 made of radiation cross-linked low-smoke halogen-free flame retardant TPE, and the Shore A hardness of the material is 50-60. Then, it is twisted into a cable in a 1+6 structure. Multiple cores greatly improve the ability to store charge. After the cable is formed, a layer of high-strength non-woven fabric is wrapped on the outside. Finally, the main core 1 and the twisted power storage core 2 are extruded through an "∞" mold. The material is a radiation cross-linked low-smoke halogen-free flame retardant TPE with a Shore A hardness of 50-60. The cable outer sheath can protect the printing and appearance while also preventing moisture in the air from penetrating into the outer sheath layer 15 and the power storage protection layer 24, thereby enhancing the cable's resistance to sunlight and aging.

[0041] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible cable for energy storage battery, characterized in that include: Main line core (1), storage line core (2), cable outer sheath (3); Wherein, the main line core (1) and the power storage line core (2) are arranged side by side; The cable outer sheath (3) is arranged outside the main wire core (1) and the wire storage core (2); The power storage wire core (2) is composed of a plurality of wire cores twisted together and then wrapped with a non-woven fabric (26); each of the wire cores comprises, from the inside to the outside, a power storage conductor (21), a graphene fiber layer (22), a metal composite layer (23), a power storage protective layer (24), and a power storage outer sheath (25).

2. A flexible cable for energy storage battery according to claim 1, characterized in that: The main line core (1) is a single-core structure, and comprises, from the inside to the outside, a main conductor (11), a conductive adhesive layer (12), an insulating layer (13), an insulating protective layer (14), an outer sheath layer (15), and an outer sheath protective layer (16).

3. A flexible cable for energy storage battery according to claim 2, characterized in that: The main conductor (11) is made of Class 6 copper conductor or tin-copper conductor, the diameter of a single wire is 0.08mm-0.12mm, and a plurality of single wires are bundled in the same direction and then layered and re-twisted. The conductive adhesive layer (12) is extruded and wrapped on the outside of the main conductor (11), and the conductive adhesive fills the gaps of the main conductor (11).

4. A flexible cable for energy storage battery according to claim 2, characterized in that: The insulating layer is irradiated cross-linked polyethylene; the insulating protective layer (14) is fluorinated modified silicone resin.

5. A flexible cable for energy storage battery according to claim 2, characterized in that: The outer sheath layer (15) is a radiation cross-linked low-smoke halogen-free flame-retardant TPE; and the outer sheath protective layer (16) is a polyether polyurethane.

6. A flexible cable for energy storage battery according to claim 1, characterized in that: The electricity storage conductor (21) is a solid copper conductor with a diameter of 0.5 mm to 0.8 mm.

7. A flexible cable for energy storage battery according to claim 1, characterized in that: The metal composite layer (23) is made of a copper-plastic composite film, and the plastic layer thereof is bonded to the graphene fiber layer (22).

8. The flexible cable for energy storage battery according to claim 1, characterized in that: The power storage outer sheath (25) and the cable outer sheath (3) are formed by extrusion of radiation cross-linked low-smoke halogen-free flame-retardant TPE material, and the material has a Shore A hardness of 50-60.

9. A production process for a flexible cable for an energy storage battery, characterized in that: A flexible cable structure for energy storage batteries according to any one of claims 1 to 8; Wherein, the cable outer sheath (3) is extruded by an ∞-shaped die.

10. The production process of a flexible cable for energy storage battery according to claim 9, characterized in that: The insulating protective layer (14) and the outer sheath protective layer (16) are formed by a static coating process.

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