Current collector, battery and electric equipment

Abstract

The utility model discloses a current collector, a battery and electric equipment. The current collector comprises a base material layer, a conductive layer and a positive temperature coefficient thermistor layer, and the base material layer comprises a first surface and a second surface along a first direction; the conductive layer is arranged on at least one of the first surface and the second surface; the positive temperature coefficient thermistor layer is arranged between the base material layer and the conductive layer. The problem that when the thinned copper foil is used as the current collector, the current collector is likely to generate an overflowing phenomenon is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage devices, in particular to a current collector, a battery and an electric device. BACKGROUND

[0002] In the prior art, lithium ion batteries are widely used in different products and fields, such as notebook computers, portable mobile phones, new energy vehicles, etc., due to their large battery capacity, long cycle life and other advantages. With the update iteration of terminal products, the demand for long cycle and high energy density of batteries is increasing.

[0003] In the production of lithium batteries, copper foil is used as the negative current collector, which has good conductivity and is soft and easy to process. However, due to the high density of copper foil itself, the total weight of the battery accounts for about 8-10%, and the industry usually thins the copper foil to reduce the weight of the battery.

[0004] However, as the thickness of the copper foil decreases, the mechanical strength of the copper foil decreases. Therefore, when the thinned copper foil is used as the current collector of the battery, the current collector is prone to overcurrent, increasing the risk of battery combustion and posing a great safety hazard to the battery. CONTENT OF THE UTILITY MODEL

[0005] The main purpose of the present application is to provide a current collector, a battery and an electric device to solve the problem of overcurrent of the current collector when the thinned copper foil is used as the current collector in the background art.

[0006] According to one aspect of the present application, a current collector is provided, comprising:

[0007] a substrate layer, along a first direction, the substrate layer comprising a first surface and a second surface;

[0008] a conductive layer, the conductive layer being provided on at least one of the first surface and the second surface;

[0009] a positive temperature coefficient thermistor layer, the positive temperature coefficient thermistor layer being provided between the substrate layer and the conductive layer.

[0010] Further, the positive temperature coefficient thermistor layer comprises a plurality of coating segments, the plurality of coating segments being spaced apart on the surface of the substrate layer, and the side of the conductive layer close to the positive temperature coefficient thermistor layer being at least partially embedded in the space between the plurality of coating segments and in contact with the surface of the substrate layer.

[0011] Further, the plurality of coating segments are spaced apart and uniformly arranged on the surface of the substrate layer along a second direction, and along a third direction, the substrate layer comprises a first side and a second side, and the plurality of coating segments cover from the first side to the second side.

[0012] Further, the coating segments comprise at least one of a straight segment and a curved segment.

[0013] Further, along a third direction, the substrate layer comprises a first side and a second side, and the coating segments cover from the first side to the second side.

[0014] Further, the coating segments comprise:

[0015] a first coating segment disposed on the first surface;

[0016] a second coating segment disposed on the second surface, and a width of the first coating segment is equal to a width of the second coating segment.

[0017] Further, the first coating segment and the second coating segment are disposed one-to-one.

[0018] Further, along a first direction, a projected outer contour of the first coating segment is at least partially misaligned with a projected outer contour of the second coating segment along a second direction.

[0019] Further, on the first surface or the second surface of the substrate layer, a maximum spacing between two adjacent coating segments is between 1 cm and 10 cm.

[0020] Further, along a second direction, a maximum width of the coating segments is between 0.1 μm and 25 mm.

[0021] Further, the current collector further comprises:

[0022] a cohesion enhancement layer disposed on a surface of the substrate layer and covering a plurality of the coating segments, and the conductive layer is disposed on a surface of the cohesion enhancement layer away from the substrate layer;

[0023] an oxidation prevention layer disposed on a surface of the conductive layer away from the substrate layer.

[0024] Further, along a first direction, a thickness of the cohesion enhancement layer is between 10 nm and 100 nm.

[0025] Further, along a first direction, a thickness of the oxidation prevention layer is between 10 nm and 100 nm.

[0026] Further, the substrate layer comprises:

[0027] at least one of a polyethylene layer, a polypropylene layer, a polyimide layer, a glass fiber layer, a cotton layer, a hemp layer, an o-phenylphenol layer, a polyimide layer, a polyethylene terephthalate layer, a chlorinated polypropylene resin layer, a polyvinyl chloride layer, or an ajinomoto build-up film layer.

[0028] Further, along the first direction, the thickness of the substrate layer is between 0.5 μm and 8 μm.

[0029] Further, along the first direction, the thickness of the conductive layer is between 100 nm and 1000 nm.

[0030] In another aspect, the application also provides a battery comprising the current collector according to any of the above technical solutions.

[0031] In another aspect, the application also provides a battery comprising the current collector according to any of the above technical solutions.

[0032] In the application, the positive temperature coefficient thermistor layer arranged between the substrate layer and the conductive layer has the characteristic that the resistivity increases rapidly with the increase of temperature. The resistance of the positive temperature coefficient thermistor layer can increase sharply after the battery overheats, thereby increasing the resistance of the current collector, effectively reducing the overcurrent phenomenon of the current collector, preventing the temperature of the battery in which the current collector is located from continuing to rise, and thereby preventing the battery from overheating. When the current collector is punctured, the positive temperature coefficient thermistor layer can increase the resistance of the punctured position of the current collector, reduce the current during short circuit, reduce the heat generated during short circuit of the current collector, reduce the danger caused by the puncture of the current collector, and effectively improve the safety of the battery in use. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application, and do not limit the application. In the drawings:

[0034] Figure 1 It is a sectional view of a current collector disclosed in the application (I);

[0035] Figure 2 It is a top view of a current collector disclosed in the application (I);

[0036] Figure 3 It is a top view of a current collector disclosed in the application (II);

[0037] Figure 4 It is a top view of a current collector disclosed in the application (III);

[0038] Figure 5 It is a sectional view of a current collector disclosed in the application (II);

[0039] Figure 6 A sectional view (three) of a current collector disclosed in the present application.

[0040] In the above drawings, reference numerals include the following:

[0041] 1, substrate layer; 11, first surface; 12, second surface; 13, first side; 14, second side; 2, conductive layer; 3, positive temperature coefficient thermistor layer; 15, first coating section; 16, second coating section; 4, adhesion enhancement layer; 5, oxidation prevention layer. DETAILED DESCRIPTION

[0042] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0043] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that the terms "comprise" and / or "include" as used in the specification indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] Unless specifically stated otherwise, the relative arrangements of the components and steps illustrated in these embodiments and the numerical expressions and values set forth in the examples are not meant to limit the scope of the present application. It should also be understood that the size of the various parts shown in the drawings can not be to scale for ease of illustration. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the description of the present application. In all examples shown and discussed herein, any specific value should be interpreted as merely an example, and not as a limitation. Therefore, other examples of the exemplary embodiments can have different values. It should be noted that similar reference numerals and letters in the following drawings represent similar items, and therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0045] Referring to Figures 1 to 6 As shown, the present application provides a current collector, which includes a substrate layer 1, a conductive layer 2, and a positive temperature coefficient thermistor layer 3. Wherein, along the direction indicated by the arrow A, specifically the thickness direction of the substrate layer 1, the substrate layer 1 includes a first surface 11 and a second surface 12. The conductive layer 2 is arranged on at least one of the first surface 11 and the second surface 12. The positive temperature coefficient thermistor layer 3 is arranged between the substrate layer 1 and the conductive layer 2. Figure 1 As shown, the present application provides a current collector, which includes a substrate layer 1, a conductive layer 2, and a positive temperature coefficient thermistor layer 3. Wherein, along the direction indicated by the arrow A, specifically the thickness direction of the substrate layer 1, the substrate layer 1 includes a first surface 11 and a second surface 12. The conductive layer 2 is arranged on at least one of the first surface 11 and the second surface 12. The positive temperature coefficient thermistor layer 3 is arranged between the substrate layer 1 and the conductive layer 2.

[0046] In the embodiment, the positive temperature coefficient thermistor layer 3 arranged between the substrate layer 1 and the conductive layer 2 has the characteristic that the resistivity increases rapidly with the increase of temperature. The internal resistance of the positive temperature coefficient thermistor layer 3 can increase sharply after the battery overheats, and the resistance of the positive temperature coefficient thermistor layer 3 can increase sharply after the battery overheats, thereby increasing the resistance of the current collector, effectively reducing the overcurrent phenomenon of the current collector, preventing the temperature of the battery where the current collector is located from continuing to rise, thereby preventing the battery from overheating and improving the structural strength of the current collector. When the current collector produces a piercing phenomenon, the positive temperature coefficient thermistor layer 3 can increase the resistance of the pierced position of the current collector, reduce the current during short circuit, reduce the heat generated during short circuit of the current collector, reduce the danger caused by piercing of the current collector, and effectively improve the safety of the battery in use. At the same time, by arranging the positive temperature coefficient thermistor layer 3 between the substrate layer 1 and the conductive layer 2, the thickness of the copper foil is thinned while the safety of the current collector is considered, the problem of the current collector being pierced due to overcurrent is reduced, and higher safety is achieved.

[0047] As shown in Figures 1 to 2 In order to make the interfacial bonding force between the conductive layer 2 and the substrate layer 1 better, thereby preventing the conductive layer 2 from being easily separated from the substrate layer 1 under the action of a larger external adhesion force. In an embodiment, the positive temperature coefficient thermistor layer 3 includes a plurality of coating sections, the plurality of coating sections are arranged on the surface of the substrate layer 1 and spaced apart from each other, and the conductive layer 2 is at least partially embedded in the space between the plurality of coating sections and in contact with the surface of the substrate layer 1. So that the conductive layer 2 can be in direct contact with the substrate layer 1, avoiding the positive temperature coefficient thermistor layer 3 completely separating the conductive layer 2 from the substrate layer 1, thereby improving the interfacial bonding force between the conductive layer 2 and the substrate layer 1. Moreover, when arranging the plurality of coating sections on the surface of the substrate layer 1, the coating tool for coating the coating sections is arranged at a specific position, and during the unwinding process of the substrate layer 1, each part of the substrate layer 1 passes through the coating tool in turn, realizing the processing and coating of the coating sections, which is convenient and efficient.

[0048] In the embodiment, when the battery using the current collector as the pole piece produces an overheating phenomenon, the internal resistance of the plurality of coating sections can rapidly increase with the increase of the temperature of the battery, so as to increase the resistance of the current collector and quickly limit the conduction of the current on the current collector, avoid the overcurrent phenomenon of the current collector, prevent the temperature of the battery from continuing to rise, and effectively improve the safety performance of the battery. The conductive layer 2 is at least partially embedded in the space between the plurality of coating sections and in contact with the surface of the substrate layer 1, which can further strengthen the interfacial bonding force between the conductive layer 2 and the substrate layer 1.

[0049] In addition, the uniform distribution of the positive temperature coefficient thermistor layer 3 can uniformly slow down the temperature rise rate of the current collector, effectively avoiding the situation where the temperature rise rate of the current collector region with a dense distribution of the positive temperature coefficient thermistor layer 3 is lower than that of the current collector region with a sparse distribution of the positive temperature coefficient thermistor layer 3, thus reducing the impact of uneven temperature rise rate on the electrochemical performance of the battery.

[0050] Generally, the positive temperature coefficient (PTC) thermistor layer 3 is made of a PTC thermistor material. PTC thermistor layer 3 is primarily a film structure formed by depositing PTC thermistor paste coated on the substrate layer 1. (PTC thermistor stands for Positive Temperature Coefficient, meaning a resistivity that increases with temperature). The PTC thermistor layer 3 exhibits the characteristic that its resistivity increases with temperature. Before reaching a specific temperature, the resistance of the PTC thermistor layer 3 changes very slowly with temperature. However, when this specific temperature is exceeded (also known as the Curie temperature), the resistance of the PTC material increases sharply, enabling it to react quickly to overload currents. This helps ensure the safety of the current collector and prevents overcurrent. Furthermore, PTC material has high impact resistance, a long service life, and a small size. It can be processed into various shapes and specifications according to actual needs, making it convenient to install on the surface of the substrate layer 1.

[0051] Specifically, the positive temperature coefficient thermistor layer 3 may include a polymer matrix, a conductive agent, inorganic particles, and a carbon-based conductive agent. The polymer matrix includes one of the following: low-density polyethylene, high-density polyethylene, epoxy resin, polyvinylidene fluoride, ethylene-ethyl acrylate copolymer, polybutene, cellulose acetate, and polyamide. The conductive agent includes one or more of the following: spiky nickel powder, spiky copper powder, spiky aluminum powder, and spiky tungsten carbide. The inorganic particles are selected from one or more of the following: alumina, silicon dioxide, aluminum hydroxide, and barium titanate. The carbon-based conductive agent is selected from one or more of the following: conductive carbon black (Super-P, Super-S, 350G, etc.) and carbon fiber (VGCF). The positive temperature coefficient thermistor layer 3 may also include a film structure formed by coating a PTC thermistor paste composed of epoxy resin, carbon black, and curing agent polyamide onto the substrate layer 1.

[0052] like Figure 2 As shown, in order to ensure uniform heat distribution in the current collector, in one embodiment, multiple coating segments are arranged along the second direction (e.g., Figure 1The arrows B indicate the direction of the length of the substrate layer 1. The plurality of coating sections are evenly arranged on the surface of the substrate layer 1. The evenly arranged coating sections can improve the uniformity of the heat distribution of the positive temperature coefficient thermistor layer 3, optimize the heat distribution, and ensure the uniformity of the heat distribution of the current collector. When the battery overheats, the evenly arranged coating sections can also uniformly hinder the conduction of the current at each part of the length of the current collector, reduce the risk of the current collector being punctured, and the uniform arrangement also facilitates processing and ensures the consistency of the quality of downstream products (such as batteries). This is because if the plurality of coating sections are not evenly distributed on the substrate layer 1, the performance difference between the batteries will be more obvious, which is not conducive to the consistency control of the quality of the batteries by the battery manufacturer. Therefore, the even arrangement of the plurality of coating sections on the substrate layer 1 can ensure the consistency of the quality of downstream products.

[0053] In the embodiment, the positive temperature coefficient thermistor layer 3 is arranged between the conductive layer and the substrate layer, which does not affect the contact between the current collector and the active material, and ensures the reliability of the current conduction.

[0054] The third direction is perpendicular to the first direction and the second direction. Figure 1 The arrows C indicate the direction of the width of the substrate layer 1. The substrate layer 1 includes a first side 13 and a second side 14. The coating section covers from the first side 13 to the second side 14 to increase the effective area of the coating section on the substrate layer 1. When the current collector overflows, the coating section covering from the first side 13 to the second side 14 can generate a larger resistance when the current conducts along the third direction, which greatly limits the conduction of the current to a certain extent, prevents the temperature from continuing to rise, protects the current collector from being punctured, and improves the structural strength of the current collector.

[0055] As shown in FIG. 1, in one embodiment, the coating section can be arranged in a straight line type, and the coating section is perpendicular to the first side 13 and the second side 14, which facilitates the processing of the coating section and reduces the processing difficulty. Figure 2 As shown in FIG. 1, in another embodiment, the coating section can be arranged in a straight line type, and the coating section is inclined to the first side 13 and the second side 14, which can increase the effective area of the coating section on the substrate layer 1 and reduce the current when the current collector is short-circuited, and quickly prevent the temperature of the battery from continuing to rise.

[0056] Figure 3 As shown in FIG. 1, in another embodiment, the coating section can be arranged in a straight line type, and the coating section is inclined to the first side 13 and the second side 14, which can increase the effective area of the coating section on the substrate layer 1 and reduce the current when the current collector is short-circuited, and quickly prevent the temperature of the battery from continuing to rise.

[0057] As shown in FIG. 1, in another embodiment, the coating section can be arranged in a straight line type, and the coating section is inclined to the first side 13 and the second side 14, which can increase the effective area of the coating section on the substrate layer 1 and reduce the current when the current collector is short-circuited, and quickly prevent the temperature of the battery from continuing to rise. Figure 4 ​As shown, in another embodiment, the coating segment can be configured as a curve to further increase the effective area of ​​the coating segment on the substrate layer 1. Therefore, the mutually spaced curved coating segments can further reduce the current during a short circuit of the current collector while ensuring a tighter bond between the conductive layer 2 and the substrate layer 1. Furthermore, when the current collector is punctured, the coating segments can cover more puncture sites to increase the resistance of the puncture point and reduce the safety hazards caused by the puncture of the current collector.

[0058] The above embodiments can be implemented individually or simultaneously. That is, the coating segment can be partially set as a straight line and partially as a curve, depending on the actual situation.

[0059] Alternatively, in another embodiment, multiple coating segments are spaced apart and evenly distributed on the surface of the substrate layer 1 along a third direction.

[0060] like Figures 1 to 5 As shown, to facilitate rapid processing of the coating segment, in one embodiment, the coating segment includes a first coating segment 15 disposed on the first surface 11 and a second coating segment 16 disposed on the second surface 12, wherein the width of the first coating segment 15 is equal to the width of the second coating segment 16. During production, the coating device for processing the coating segment is fixed to ensure uniform unwinding and rewinding speed of the substrate layer 1, thereby enabling rapid and efficient processing of the first coating segment 15 and the second coating segment 16 with equal widths. This configuration improves the production efficiency of the current collector and facilitates processing.

[0061] Specifically, the first coating segment 15 and the second coating segment 16 are arranged in a one-to-one correspondence. This facilitates production and processing, and at the same time, helps to ensure the uniformity of mechanical strength of various parts of the current collector.

[0062] Or, such as Figure 5 As shown, along the first direction, the projected outer contour of the first coating segment 15 is at least partially offset along the second direction from the projected outer contour of the second coating segment 16. That is, the first coating segment 15 and the second coating segment 16 can be offset along the second direction to increase the effective area of ​​the coating segments on the substrate layer 1, so as to quickly prevent the battery temperature from continuing to rise after the current collector generates an overcurrent phenomenon.

[0063] Alternatively, the above embodiments can be implemented simultaneously, with some of the first coating segments 15 and some of the second coating segments 16 being arranged in a one-to-one correspondence, and some of the first coating segments 15 and some of the second coating segments 16 being distributed alternately. This embodiment is not limited to a single one.

[0064] like Figures 1 to 6As shown, in one embodiment, the maximum spacing H between two adjacent coating segments on the first surface 11 or the second surface 12 of the substrate layer 1 is between 1 cm and 10 cm. Specifically, the maximum spacing H between two adjacent coating segments can be set to one of 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, or 10 cm to ensure that the coating segments can uniformly block current, uniformly prevent the temperature from rising continuously, and ensure uniform heat distribution of the current collector. If the maximum spacing H between two adjacent coating segments is less than 1 cm, the contact area between the conductive layer 2 and the substrate layer 1 will be too small, affecting the interfacial bonding force between the conductive layer 2 and the substrate layer 1. If the maximum spacing H between two adjacent coating segments is greater than 10 cm, when the temperature in the area between two adjacent coating segments is too high, the internal resistance of the coating segment cannot rise in time to block the current, which may easily cause the current collector to be punctured due to overcurrent, posing a significant safety hazard.

[0065] In one embodiment, the maximum width D of the coating segment is between 0.1 μm and 25 mm. For example, the maximum width D of the coating segment can be set to one of 0.1 μm, 100 μm, 500 μm, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, etc., so that when the current collector is overcurrent, the coating segment can effectively block the current and prevent the temperature of the current collector from rising continuously.

[0066] If the maximum width D of the coating segment is less than 0.1 μm, the width of the coating segment is too small and cannot generate enough internal resistance to block the current. Overcurrent will easily cause the current collector temperature to rise continuously, which has already caused a safety problem. If the maximum width D of the coating segment is greater than 25 mm, it will affect the contact area between the conductive layer 2 and the substrate layer 1, which is not conducive to the performance of the conductive layer 2.

[0067] like Figure 6 As shown, in one embodiment, the current collector further includes an adhesion enhancement layer 4, which is disposed on the surface of the substrate layer 1 and covers multiple coating segments. The conductive layer 2 is disposed on the surface of the adhesion enhancement layer 4 away from the substrate layer 1. The adhesion enhancement layer 4 can improve the adhesion of the conductive layer 2 to the substrate layer 1, thereby further ensuring that the conductive layer 2 is not prone to detachment or sporadic peeling from the substrate layer 1, improving the structural stability and product quality of the current collector. The adhesion enhancement layer 4 can form an extremely thin chemical bond layer on the surface of the substrate layer 1, which can fill the small defects on the surface of the substrate layer 1 and increase the surface roughness, making the contact between the conductive layer 2 and the substrate layer 1 tighter. This results in a larger contact area and stronger interaction force on the bonding surface, significantly enhancing the bonding strength between the substrate layer 1 and the conductive layer 2, while ensuring that the multiple coating segments remain stably located on the surface of the substrate layer 1 without relative displacement.

[0068] The adhesion-enhancing layer can be a metallic coating, such as a nickel or chromium layer; or it can be a non-metallic coating, such as a graphene layer, silicon carbide layer, silicon nitride layer, or aluminum oxide layer. It is understood that the materials of the adhesion-enhancing layer include, but are not limited to, these, and the specific materials will depend on the actual situation.

[0069] Along the first direction, the thickness d1 of the adhesion enhancement layer 4 is between 10 nm and 100 nm. For example, the thickness d1 of the adhesion enhancement layer can be set to one of 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm. The adhesion enhancement layer 4 provides sufficient adhesion strength to ensure a tight bond between the layers of the current collector, preventing interlayer separation or detachment due to vibration, impact, or other factors during battery use, thus ensuring the stability and reliability of the current collector. The adhesion enhancement layer 4 also provides the current collector with a certain degree of flexibility and mechanical strength, further ensuring the stability and safety of the current collector. If the thickness d1 of the adhesion enhancement layer is less than 10 nm, it may result in poor adhesion strength, affecting the stability of the current collector. If the thickness d1 of the adhesion enhancement layer is greater than 100 nm, it may affect the connection between the conductive layer and the substrate layer, thus affecting the electrical conductivity of the current collector.

[0070] like Figure 6 As shown, in one embodiment, the current collector further includes an anti-oxidation layer 5, which is disposed on the surface of the conductive layer 2 away from the substrate layer 1. The anti-oxidation layer 5 can effectively prevent the conductive layer 2 from undergoing oxidation under the influence of the external environment, and prevent the conductivity of the conductive layer 2 from being affected after oxidation. Therefore, the anti-oxidation layer 5 can greatly extend the service life of the current collector, ensuring that it can maintain stable conductivity during long-term use.

[0071] Along the first direction, the thickness d2 of the anti-oxidation layer is between 10 nm and 100 nm. For example, the thickness d2 of the anti-oxidation layer can be set to one of 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm. This helps to protect the conductive layer 2 from the influence of the external environment, prevent the conductive layer 2 from oxidation, improve the overall performance of the current collector, and also improve the structural strength of the current collector. If the thickness d2 of the anti-oxidation layer is less than 10 nm, the thin anti-oxidation layer 5 may be more easily penetrated or damaged, leading to oxidation of the conductive layer 2, which in turn affects the performance and lifespan of the current collector, and also increases the processing difficulty. If the thickness d2 of the anti-oxidation layer is greater than 100 nm, the anti-oxidation layer 5 is too thick, which will increase the resistance of the current collector and lead to a decrease in conductivity.

[0072] The anti-oxidation layer 5 can be a dense metal layer, for example, the anti-oxidation layer 5 can be a nickel layer, a chromium layer, a nickel alloy layer, or a chromium alloy layer, etc. Alternatively, the anti-oxidation layer 5 can also be a non-metal layer, and the anti-oxidation layer 5 can be a graphene layer, an aluminum oxide layer, a silicon nitride layer, or a silicon carbide layer, etc. Specifically, the material and thickness of the anti-oxidation layer 5 can be optimized according to the specific application scenario.

[0073] In one embodiment, the substrate layer 1 comprises at least one of a polyethylene layer, a polypropylene layer, a polyimide layer, a glass fiber layer, a cotton layer, a hemp layer, an o-phenylphenol layer, a polyimide layer, a polyethylene terephthalate layer, a chlorinated polypropylene resin layer, a polyvinyl chloride layer, or an Ajinomoto build-up film layer. Preferably, the material of the substrate layer 1 is selected from an Ajinomoto build-up film (ABF film for short), which is a highly durable and rigid film that can effectively resist expansion and contraction under temperature changes, ensuring that the current collector can maintain stable performance in various environments, thereby improving the reliability and safety of the current collector and prolonging the service life of the current collector. In addition, the surface of the ABF film can be subjected to laser processing and direct copper plating, ensuring that the current collector can be processed and prepared in a “one-step method”, thereby simplifying the production process and improving production efficiency.

[0074] In the first direction, the thickness d3 of the substrate layer 1 is between 0.5 μm and 8 μm. For example, the thickness d3 of the substrate layer 1 can be one of 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, etc., ensuring that the substrate layer 1 has sufficient strength and rigidity to resist current impact and temperature changes during battery charging and discharging, ensuring the stability and reliability of the current collector, while achieving lightweight of the battery. If the thickness d3 of the substrate layer is less than 0.5 μm, the substrate layer 1 is too thin, and the mechanical strength of the substrate layer 1 is low, which causes the current collector to be unable to withstand the impact of the current and the temperature changes inside the battery, which may cause the current collector to break, be punctured, etc., affecting the normal use of the current collector; if the thickness d3 of the substrate layer is greater than 8 μm, the substrate layer 1 is too thick, which directly causes the weight of the current collector and even the entire battery to increase, affecting its portability. Moreover, the thickness of the substrate layer 1 is too thick, which also reduces the energy density of the battery, thereby reducing the energy storage capacity of the battery.

[0075] Preferably, the thickness d3 of the substrate layer is set to 0.5 μm to 1 μm, and specifically, the thickness d3 of the substrate layer can be one of 0.5 μm, 0.6 μm, 0.7 μm, 0.75 μm, 0.8 μm, 0.9 μm, 1 μm, etc., ensuring the structural strength of the substrate layer 1 while considering the stability and reliability of the current collector.

[0076] When the substrate layer 1 is set as an ABF film layer (ABF, Ajinomoto Build-up Film, also known as Ajinomoto Build-up Film), the substrate layer 1 can resist expansion and contraction when the temperature changes, can make the current collector have stronger tensile strength, can make the current collector have a larger change window of tension, pressure, etc. in each preparation process, so that a higher pressure can be applied to the current collector in the preparation section to achieve a larger compaction density of the current collector, thereby improving the process manufacturing capacity. In view of the above advantages of the ABF film layer, the surface of the substrate layer 1 can be subjected to laser processing and direct copper plating, so that the current collector can be processed and prepared by a "one-step method", thereby improving the preparation efficiency of the current collector.

[0077] Therefore, in combination with the above embodiments, when the material of the substrate layer 1 is selected as the Ajinomoto Build-up Film and the thickness d3 of the substrate layer is set as 0.5-1 μm, compared with the existing current collector structure, the weight of the current collector using the substrate layer 1 can be reduced by 50% compared with the weight of the existing current collector structure, the thickness of the current collector can be reduced by 30% compared with the thickness of the existing current collector structure, and the battery energy density is significantly improved.

[0078] The thickness d4 of the conductive layer is between 100 nm and 1000 nm, for example, the thickness d4 of the conductive layer can be set as one of 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, etc. The conductive layer 2 can form a continuous and stable conductive channel to ensure that the current can flow smoothly and the electrical conductivity of the current collector is good. If the thickness d4 of the conductive layer is less than 100 nm, the current carrying capacity of the conductive layer 2 is poor and is easy to burn and damage; if the thickness d4 of the conductive layer is greater than 1000 nm, the overall weight and volume of the current collector will be increased, which is not convenient for installation and use.

[0079] In summary, by setting the positive temperature coefficient thermistor layer 3 between the substrate layer 1 and the conductive layer 2, the electrical resistance and mechanical strength of the current collector can be increased. When the current collector is pierced, the electrical resistance of the pierced point of the current collector can be increased, the current when the current collector is short-circuited can be reduced, and the heat generated when short-circuited can be reduced, thereby reducing the danger caused by the piercing of the current collector.

[0080] In addition, the present application can reduce the thickness of the current collector, thereby reducing the weight of the current collector in the battery, indirectly improving the energy density of the battery. At the same time, the sheet resistance of the surface of the current collector is reduced, the risk of battery combustion is reduced, the mechanical strength of the current collector is improved, and the working performance of the battery is improved.

[0081] The present application also provides a battery, which comprises a current collector, and the current collector adopts the current collector in any one of the above embodiments.

[0082] The battery includes one of a ternary lithium battery, a lithium iron phosphate battery, etc. The working temperature range of the ternary lithium battery is generally between -20°C and 60°C, and the performance of the ternary lithium battery is relatively stable within this temperature range. However, when the temperature drops below 0°C, the performance of the ternary lithium battery begins to gradually decrease, and the discharge capacity and overall service life are both affected and decreased. Therefore, in consideration of keeping the ternary lithium battery in a better performance and a longer service life, the use temperature of the ternary lithium battery is preferably controlled between 0°C and 40°C. Therefore, based on the use temperature range of the ternary lithium battery, the Curie temperature of the positive temperature coefficient thermistor layer 3 in the ternary lithium battery can be controlled between 80°C and 100°C, such as 80°C, 84°C, 88°C, 90°C, 94°C, 96°C, 100°C, etc.

[0083] Since the thermal runaway temperature of the lithium iron phosphate battery is generally above 500°C, the Curie temperature of the positive temperature coefficient thermistor layer 3 in the lithium iron phosphate battery can not be particularly limited, and can be below 400°C, for example, 100°C, 200°C, 300°C, 350°C, etc.

[0084] The application also provides a power consumption device including a battery, and the battery adopts the battery in the above embodiments. Therefore, the power consumption device and the battery include all the technical effects of the above current collector. Since the technical effects of the current collector have been described in detail above, they will not be described here.

[0085] For ease of description, spatial relative terms such as "above", "upper", "top", "up", etc. can be used herein to describe the spatial relationship between one device or feature and another device or feature as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "above" the other device or structure will be positioned "below" or "below" the other device or structure. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0086] In addition, it should be noted that the use of the terms "first", "second", etc. to define parts only facilitates the differentiation of the corresponding parts, and the above terms have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the application.

[0087] The above merely provides preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A current collector characterized by comprising: The application relates to a current collector, comprising: a substrate layer (1) comprising a first surface (11) and a second surface (12) along a first direction; an electrically conductive layer (2) arranged on at least one of the first surface (11) and the second surface (12); a positive temperature coefficient thermistor layer (3) arranged between the substrate layer (1) and the electrically conductive layer (2).

2. The current collector of claim 1, wherein The positive temperature coefficient thermistor layer (3) comprises a plurality of coating sections arranged on the surface of the substrate layer (1) and spaced from each other, and the electrically conductive layer (2) is at least partially embedded in the space between the plurality of coating sections and in contact with the surface of the substrate layer (1) on the side close to the positive temperature coefficient thermistor layer (3).

3. The current collector of claim 2, wherein The plurality of coating sections are arranged on the surface of the substrate layer (1) along a second direction and uniformly distributed; and / or, along a third direction, the substrate layer (1) comprises a first side (13) and a second side (14), and the plurality of coating sections cover from the first side (13) to the second side (14).

4. The current collector of claim 2, wherein The coating sections comprise at least one of a straight section and a curved section.

5. The current collector according to any one of claims 2 to 4, wherein The coating sections comprise: a first coating section (15) arranged on the first surface (11); a second coating section (16) arranged on the second surface (12), and the width of the first coating section (15) is equal to the width of the second coating section (16).

6. The current collector of claim 5, wherein The first coating section (15) and the second coating section (16) are arranged one by one; and / or, along the first direction, the projection outer contour of the first coating section (15) is at least partially offset along the second direction from the projection outer contour of the second coating section (16).

7. The current collector according to any one of claims 2 to 4, 6, wherein On the first surface (11) or the second surface (12) of the substrate layer (1), the maximum distance between two adjacent coating sections is between 1 cm and 10 cm; and / or, the maximum width of the coating section is between 0.1 microns and 25 mm.

8. The current collector according to any one of claims 2 to 4, 6, wherein Further comprising: a bonding force enhancement layer (4) arranged on the surface of the substrate layer (1) and covering the plurality of coating sections, and the electrically conductive layer (2) is arranged on the surface of the bonding force enhancement layer (4) away from the substrate layer (1); and / or, an oxidation prevention layer (5) arranged on the surface of the electrically conductive layer (2) away from the substrate layer (1).

9. The current collector of claim 8, wherein Along the first direction, the thickness of the bonding force enhancement layer (4) is between 10 nm and 100 nm; and / or, along the first direction, the thickness of the oxidation prevention layer (5) is between 10 nm and 100 nm.

10. The current collector of claim 8, wherein Along the first direction, the thickness of the substrate layer (1) is between 0.5 microns and 8 microns; and / or, Along the first direction, the thickness of the electrically conductive layer (2) is between 100 nm and 1000 nm.

11. A battery, characterized by The application further relates to a battery comprising the current collector according to any one of claims 1 to 10.

12. An electrical device, characterized by The application further relates to a battery comprising the battery according to claim 11.

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