Composite current collector post-preparation device

Abstract

This invention belongs to the field of battery manufacturing technology and discloses a composite current collector post-processing apparatus. This apparatus uses a metal vapor evaporator to inject metal vapor into a vacuum chamber through the evaporation opening of the main baffle. Part of the metal vapor crosses the gap between the adjustable baffle and the main roller, forming an initial metal layer on the base film. Under the action of oxygen purging by the oxygen supply device, the initial metal layer is oxidized into an oxide metal layer. With the movement of the first and second rollers, the oxide metal layer moves between the second roller and the main baffle, where metal vapor continues to deposit on the oxide metal layer to form a composite metal layer. By depositing the aforementioned oxide metal layer and composite metal layer on both sides of the base film respectively, the desired composite current collector is finally obtained. This composite current collector post-processing apparatus can form the desired oxide metal layer and composite metal layer on the base film in one step, saving equipment and production costs and achieving higher production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and in particular to a composite current collector preparation device. Background Technology

[0002] The new energy vehicle and energy storage markets have strong growth prospects, which has driven the demand for lithium batteries. However, with the rapid development of the industry, higher requirements have been placed on the performance of lithium batteries.

[0003] The limitations of traditional current collectors have spurred the development of the composite current collector materials industry, which represents the most promising alternative current collector materials available today. Among these, composite metal films can replace traditional aluminum and copper foils as current collectors in lithium-ion batteries, significantly improving both energy density and safety performance. Specifically, composite aluminum foil and composite copper foil are used at the positive and negative electrodes of the battery, respectively.

[0004] Existing composite aluminum foils are typically manufactured using a vapor deposition process, where high-temperature molten metal is evaporated onto a base film to achieve aluminum plating. The composite aluminum foil vapor deposition process mainly includes steps such as vacuum reactive coating (CVD to form an alumina substrate), vacuum coating (PVD), slitting, packaging, and storage. In the vacuum reactive coating process, alumina is deposited on the surface of the base film as a dense auxiliary layer. Subsequently, the vacuum aluminum plating process directly deposits gaseous aluminum onto the surface of the alumina layer, forming a metallic aluminum layer. The presence of the alumina layer enhances the adhesion between the metallic aluminum layer and the substrate.

[0005] The existing vapor deposition process used for composite aluminum foil requires that after the alumina layer is deposited, the resulting base film is wound up and reused for subsequent deposition of the metallic aluminum layer. This process has the following disadvantages: 1. The thickness of the alumina layer is uncontrollable, requiring multiple vapor depositions to obtain the desired thickness. Increased deposition times significantly burden production costs. Furthermore, if the alumina layer is too thick after multiple depositions, it can lead to decreased conductivity and adhesion of the current collector, making the metallic aluminum layer prone to detachment. 2. During reuse, the alumina layer reacts with atmospheric oxygen and other gases, causing further oxidation and making the composition of the alumina layer uncontrollable. 3. Alumina is hygroscopic and requires specific storage conditions. After the base film absorbs moisture, vacuum drying of the composite aluminum foil is necessary, increasing manufacturing costs.

[0006] Therefore, there is an urgent need to provide a novel post-processing device for composite current collectors to solve the aforementioned technical problems in the prior art. Utility Model Content

[0007] The purpose of this invention is to provide a composite current collector preparation device that can form the required oxide metal layer and composite metal layer on the base film in one step, saving equipment and production costs, and increasing production efficiency.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] The composite current collector preparation apparatus includes a vacuum chamber, a shielding assembly, a metal vapor evaporation device, and an oxygen supply device. A first roller and a second roller are spaced apart along a first direction within the vacuum chamber. A main roller is positioned between the first roller and the second roller. The first roller unwinds the base film, the second roller rewinds the base film, and the main roller supports the base film downwards. The shielding assembly is disposed within the vacuum chamber and includes a main shielding plate and an adjustable baffle. The evaporation opening of the main shielding plate is located directly below the main roller. The adjustable baffle is vertically disposed on the upper surface of the main shielding plate, at the end of the evaporation opening along the first direction near the first roller. The metal vapor evaporation device injects metal vapor into the vacuum chamber from the evaporation opening. The oxygen supply device is disposed at the end of the adjustable baffle along the first direction away from the evaporation opening and purges oxygen onto the bottom wall of the base film.

[0010] Optionally, the flow rate of the purging oxygen ranges from 100 sccm to 1000 sccm.

[0011] Optionally, the oxygen supply device includes a plurality of blowing pipes extending along the second direction and connected end to end, and each of the blowing pipes is provided with a blowing hole for blowing oxygen.

[0012] Optionally, the aforementioned air blowing pipe is equipped with a mass flow meter, which is used to monitor the oxygen flow rate within the air blowing pipe.

[0013] Optionally, the top wall of the main baffle is provided with a cooling pipe, which surrounds the evaporation opening and is used for heat exchange with metal vapor.

[0014] Beneficial effects:

[0015] The composite current collector preparation apparatus uses a first roller to unwind the base film, a second roller to rewind the base film, and a main roller to support the base film downwards. A metal vapor evaporator injects metal vapor into the vacuum chamber through the evaporation opening of the main baffle. Some of the metal vapor passes through the gap between the adjustable baffle and the main roller, forming an initial metal layer on the base film. Under the action of oxygen purging from the oxygen supply device, this initial metal layer is oxidized into an oxide metal layer. By adjusting the vertical height H of the gap between the top of the main roller and the adjustable baffle, the amount of metal vapor passing through the adjustable baffle can be adjusted, thereby adjusting the thickness of the oxide metal layer. As the first and second rollers move, the oxide metal layer moves between the second roller and the main baffle. At this point, the metal vapor that has not passed through the adjustable baffle continues to deposit on the oxide metal layer to form a composite metal layer. By depositing the aforementioned oxide metal layer and composite metal layer on both sides of the base film respectively, the desired composite current collector is finally obtained. This composite current collector post-processing device can form the required oxide metal layer and composite metal layer in one pass using the same metal vapor evaporation equipment during the base film unwinding and rewinding process. It eliminates the need for repeated unwinding and rewinding of the base film to deposit the composite metal layer, reducing the number of evaporation cycles and eliminating the need for post-oxidation metal layer turnover, thus ensuring the quality of the oxide metal layer. Furthermore, it eliminates the need for vacuuming the composite aluminum foil, lowering equipment and production costs while improving production quality and efficiency. This composite current collector post-processing device can form the required oxide metal layer and composite metal layer on the base film in one pass, saving equipment and production costs while achieving higher production efficiency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the composite current collector preparation device provided in a specific embodiment of this utility model;

[0017] Figure 2 This is a schematic diagram of a portion of the composite current collector preparation device provided in a specific embodiment of this utility model;

[0018] Figure 3 This is a top view of a portion of the composite current collector preparation device provided in a specific embodiment of this utility model.

[0019] In the picture:

[0020] vacuum chamber

[0021] 10. Base film; 1. First roller; 2. Second roller; 3. Main roller; 4. Shielding assembly; 41. Main shielding plate; 411. Evaporation opening; 42. Adjustable baffle; 5. Oxygen supply device; 51. Air blowing pipe; 52. Mass flow meter; 6. Cooling pipeline; 61. Coolant inlet; 62. Coolant outlet. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0023] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0026] The first direction described in this embodiment is: Figures 1 to 3 The X direction shown is the length direction of the base film 10; the second direction is... Figure 3 The Y direction shown is the width direction of the base film 10, and the first direction is perpendicular to the Y direction.

[0027] like Figure 1 and Figure 2As shown, this embodiment first provides a composite current collector post-processing apparatus, which uses the composite current collector post-processing method described in this embodiment, including a vacuum chamber, a shielding assembly 4, a metal vapor evaporation device, and an oxygen supply device 5. A first roller 1 and a second roller 2 are spaced apart along a first direction within the vacuum chamber. A main roller 3 is disposed between the first roller 1 and the second roller 2. The first roller 1 is used to unwind the base film 10, the second roller 2 is used to rewind the base film 10, and the main roller 3 is used to support the base film 10 downwards. The shielding assembly 4 is disposed within the vacuum chamber and includes a main shielding assembly. The main baffle 41 and the adjustable baffle 42 are provided. The evaporation opening 411 of the main baffle 41 is located directly below the main roller 3. The adjustable baffle 42 is vertically disposed on the upper surface of the main baffle 41 and is located at the end of the evaporation opening 411 close to the first roller 1 along the first direction. The metal vapor evaporation device is used to inject metal vapor into the vacuum chamber from the evaporation opening 411. The oxygen supply device 5 is disposed at the end of the adjustable baffle 42 away from the evaporation opening 411 along the first direction and is used to purge oxygen onto the bottom wall of the base film 10.

[0028] This composite current collector preparation apparatus can unwind the base film 10 using a first roller 1, rewind the base film 10 using a second roller 2, and support the base film 10 downwards using a main roller 3. Metal vapor is injected into the vacuum chamber through the evaporation opening 411 of the main baffle plate 41 using a metal vapor evaporator. Part of the metal vapor crosses the gap between the adjustable baffle plate 42 and the main roller 3, thus forming an initial metal layer on the base film 10. Under the action of purging oxygen from the oxygen supply device 5, this initial metal layer is oxidized into a metal oxide layer. The main roller 3 is then adjusted... The vertical height H of the gap between the adjustable baffle 42 and the top of the adjustable baffle 42 can be used to adjust the amount of metal vapor passing through the adjustable baffle 42, thereby adjusting the thickness of the oxide metal layer. As the first roller 1 and the second roller 2 move, the oxide metal layer moves between the second roller 2 and the main baffle 41. At this time, the metal vapor that has not passed through the adjustable baffle 42 continues to deposit on the oxide metal layer to form a composite metal layer. By depositing the above-mentioned oxide metal layer and composite metal layer on both sides of the base film 10 respectively, the desired composite current collector is finally obtained. This composite current collector preparation device can form the oxide metal layer and composite metal layer of the required thickness in one go using the same metal vapor evaporation device during the winding and unwinding process of the base film 10, without having to wind and unwind the base film 10 to deposit the composite metal layer again. This not only reduces the number of evaporation cycles, but also eliminates the need for turnover after the oxide metal layer is produced, ensuring the production quality of the oxide metal layer. At the same time, it eliminates the need to use equipment to vacuum the composite aluminum foil, reducing equipment costs and production costs, and improving production quality and efficiency.

[0029] Furthermore, the aforementioned oxygen supply device 5 includes several air blowing pipes 51 extending along the second direction and connected end to end, each of which has a purging hole for blowing oxygen. In this embodiment, the air blowing pipe 51 is provided with 3 to 8 sections, each of which can blow oxygen, thus ensuring the uniformity of oxygen blowing by the oxygen supply device 5, improving the uniformity and consistency of the oxide metal layer, and improving production quality.

[0030] In this embodiment, the air blowing pipe 51 is equipped with a mass flow meter 52, which is used to monitor the oxygen flow rate within the air blowing pipe 51. Therefore, by monitoring the oxygen flow rate within the air blowing pipe 51, the oxygen flow rate can be controlled, ensuring that the amount of oxygen purged from the oxygen pipe is sufficient to produce an oxide metal layer of the required thickness and oxidation degree, thus achieving controllable thickness and oxidation degree of the oxide metal layer during the production process.

[0031] Furthermore, such as Figure 2 and Figure 3 As shown, a cooling pipe 6 is provided on the top wall of the main baffle plate 41. The cooling pipe 6 surrounds the evaporation opening 411 and is used for heat exchange with the metal vapor. When the metal vapor evaporation device injects metal vapor into the vacuum chamber from the evaporation opening 411, the cooling pipe 6 is used to exchange heat with the metal vapor, thereby rapidly cooling the metal vapor, facilitating the deposition of the metal vapor on the surface of the base film 10, and improving the adhesion of the formed oxide metal layer and composite metal layer, thus improving the product quality of the final formed composite current collector.

[0032] In this embodiment, the cooling pipe 6 is provided with a coolant inlet 61 and a coolant outlet 62 for the circulation of coolant in the cooling pipe 6 to achieve continuous heat exchange between the coolant and the metal vapor, which will not be described in detail here.

[0033] like Figures 1 to 3As shown, this embodiment also provides a method for preparing a composite current collector, which includes the following steps: S1, a first roller 1 and a second roller 2 are spaced apart along a first direction in a vacuum chamber, and a main roller 3 is placed between the first roller 1 and the second roller 2. The first roller 1 unwinds the base film 10, the second roller 2 winds the base film 10, and the main roller 3 supports the base film 10 downwards; S2, a shielding assembly 4 is provided in the vacuum chamber. The shielding assembly 4 includes a main shielding plate 41 and an adjustable baffle 42. The evaporation opening 411 of the main shielding plate 41 is located directly below the main roller 3, and the adjustable baffle 42 is perpendicular to the upper surface of the main shielding plate 41 and is located at the end of the evaporation opening 411 near the first roller 1 along the first direction; S3, metal vapor is injected into the vacuum chamber through the evaporation opening 411 using a metal vapor evaporation device. S4. An oxygen supply device 5 is provided at one end of the adjustable baffle 42 away from the evaporation opening 411 along the first direction. The oxygen supply device 5 blows oxygen to the bottom wall of the base film 10. The initial metal layer located between the first roller 1 and the adjustable baffle 42 is oxidized and deposited as an oxide metal layer. The vertical height H of the gap between the main roller 3 and the top of the adjustable baffle 42 is adjusted to change the thickness of the oxide metal layer. S5. During the process of the base film 10 moving from the first roller 1 to the second roller 2, the oxide metal layer moves to the space between the second roller 2 and the adjustable baffle 42. Metal vapor is deposited on the surface of the oxide metal layer to form a composite metal layer. S6. The oxide metal layer and the composite metal layer are deposited on both sides of the base film 10 to obtain the desired composite current collector.

[0034] This composite current collector preparation method uses a first roller 1 to unwind the base film 10, a second roller 2 to rewind the base film 10, and a main roller 3 to support the base film 10 downwards. Metal vapor is injected into the vacuum chamber through the evaporation opening 411 of the main baffle 41 using a metal vapor evaporation device. Part of the metal vapor passes through the gap between the adjustable baffle 42 and the main roller 3, thus forming an initial metal layer on the base film 10. Under the action of purging oxygen from the oxygen supply device 5, this initial metal layer is oxidized into a metal oxide layer. The process is further refined by adjusting the main roller 3. The vertical height H of the gap between the adjustable baffle 42 and the top of the adjustable baffle 42 can be used to adjust the amount of metal vapor passing through the adjustable baffle 42, thereby adjusting the thickness of the oxide metal layer. As the first roller 1 and the second roller 2 move, the oxide metal layer moves between the second roller 2 and the main baffle 41. At this time, the metal vapor that has not passed through the adjustable baffle 42 continues to deposit on the oxide metal layer to form a composite metal layer. By depositing the above-mentioned oxide metal layer and composite metal layer on both sides of the base film 10 respectively, the desired composite current collector is finally obtained. This composite current collector preparation method can form the oxide metal layer and composite metal layer of the required thickness in one go using the same metal vapor evaporation device during the winding and unwinding process of the base film 10, without having to wind and unwind the base film 10 to deposit the composite metal layer again. This not only reduces the number of evaporation cycles, but also eliminates the need for turnover after the oxide metal layer is produced, ensuring the production quality of the oxide metal layer. At the same time, it eliminates the need to use equipment to vacuum the composite aluminum foil, reducing equipment costs and production costs, and improving production quality and efficiency. This composite current collector post-processing method can form the required oxide metal layer and composite metal layer on the base film 10 in one step, saving equipment and production costs, and with higher production efficiency.

[0035] Furthermore, step S4 also includes the step of controlling the oxygen flow rate of the oxygen supply device 5 to purge the bottom wall of the base film 10, thereby changing the oxidation degree of the oxide metal layer. The oxygen flow rate ranges from 100 sccm to 1000 sccm. By controlling the oxygen flow rate, and simultaneously controlling the gap size between the adjustable baffle 42 and the main roller 3, the material ratio, oxidation degree, and film thickness of the oxide metal layer can be effectively controlled, improving production controllability and production quality.

[0036] Optionally, step S5 further includes monitoring the sheet resistance of the base film 10 on which the aforementioned oxide metal layer and composite metal layer are deposited; if the sheet resistance is less than a preset value, the composite metal layer is too thick, and the oxygen flow rate is increased; if the sheet resistance is greater than the preset value, the oxide metal layer is too thick, and the oxygen flow rate is decreased. By monitoring the sheet resistance of the base film 10 in real time, the thickness of the oxide metal layer can be indirectly fed back through the magnitude and change of the sheet resistance, thereby facilitating the adjustment of the oxygen input.

[0037] Specifically, the monitored sheet resistance values ​​include the first sheet resistance value of the base film 10 along the first direction and the second sheet resistance value of the base film 10 along the second direction. By monitoring the sheet resistance values ​​in different directions, the thickness of the oxide metal layer and the composite metal layer in the length and width directions of the base film 10 can be monitored, ensuring that the thickness of the oxide metal layer and the composite metal layer of the base film 10 remains consistent in both the length and width directions, thereby improving production quality.

[0038] In this embodiment, when monitoring the first resistance value, the first resistance value of the base film 10 at different positions along the second direction corresponding to the position of the air blowing pipe 51 is monitored. If the first resistance value differs from the preset value, the oxygen flow rate of the corresponding air blowing pipe 51 is adjusted. That is, due to the slight difference of each air blowing pipe 51, the thickness of the oxide metal layer and composite metal layer formed at each air blowing pipe 51 is slightly different. Therefore, it is necessary to monitor the position corresponding to different air blowing pipes 51. If the first resistance value at a certain position is too low, the oxygen flow rate is increased; if the first resistance value is too high, the oxygen flow rate is decreased. This ensures that the oxide metal layer and composite metal layer produced at each air blowing pipe 51 meet the standards, improving production quality and also improving the uniformity and consistency of the oxide metal layer and composite metal layer on the product surface.

[0039] Optionally, step S3 further includes a cooling step. The top wall of the main baffle plate 41 is provided with a cooling pipe 6, which surrounds the evaporation opening 411. When the metal vapor evaporation device injects metal vapor into the vacuum chamber from the evaporation opening 411, the cooling pipe 6 is used for heat exchange with the metal vapor. The cooling step can rapidly cool the metal vapor, facilitating its deposition on the surface of the base film 10, and improving the adhesion of the formed oxide metal layer and composite metal layer, thereby improving the product quality of the final composite current collector.

[0040] Optionally, the thickness of the aforementioned oxide metal layer is from 3 nm to 50 nm, and the thickness of the aforementioned composite metal layer is from 0.1 μm to 3 μm. The thickness of the oxide metal layer and the composite metal layer are determined by the product requirements of the resulting composite current collector, and will not be elaborated here.

[0041] In this embodiment, the metal vapor can be aluminum vapor or copper vapor, specifically aluminum vapor, and the resulting composite current collector is vapor-deposited aluminum foil.

[0042] The preparation method of this composite current collector is described in detail below with reference to specific embodiments and comparative examples:

[0043] Example 1

[0044] A roll-to-roll evaporation coating equipment is used, with a vacuum level of 5.0E-3Pa in the vacuum chamber. The evaporation opening 411 has a dimension of 300mm along the first direction. The vertical gap H between the adjustable baffle 42 and the main roller 3 is 5mm. Aluminum wire with a diameter of φ1.8mm is used, and the wire feeding speed is 650mm / min for aluminum evaporation. The winding speed of the first roller 1 and the second roller 2 is 30m / min. The air blowing pipe 51 is set with 4 sections, and the air flow of each air blowing pipe 51 is 100sccm. The sheet resistance is monitored online, and the bonding force is measured offline.

[0045] Example 2

[0046] A roll-to-roll evaporation coating equipment is used, with a vacuum level of 5.0E-3Pa in the vacuum chamber. The evaporation opening 411 has a dimension of 300mm along the first direction. The vertical gap H between the adjustable baffle 42 and the main roller 3 is 5mm. Aluminum wire with a diameter of φ1.8mm is used, and the wire feeding speed is 750mm / min for aluminum evaporation. The winding speed of the first roller 1 and the second roller 2 is 30m / min. The air blowing pipe 51 is set with 4 sections, and the air flow of each air blowing pipe 51 is 120sccm. The sheet resistance is monitored online, and the bonding force is measured offline.

[0047] Comparative Example 1

[0048] A roll-to-roll evaporation coating equipment is used, with a vacuum level of 5.0E-3Pa in the vacuum chamber. The evaporation opening 411 has a dimension of 300mm along the first direction. The vertical gap H between the adjustable baffle 42 and the main roller 3 is 5mm. Aluminum wire with a diameter of φ1.8mm is used, and the wire feeding speed is 650mm / min for aluminum evaporation. The winding speed of the first roller 1 and the second roller 2 is 30m / min. The air blowing pipe 51 is set with 4 sections, and the air flow of each air blowing pipe 51 is 200sccm. The sheet resistance is monitored online, and the bonding force is measured offline.

[0049] Comparative Example 2

[0050] A roll-to-roll evaporation coating equipment is used, with a vacuum level of 5.0E-3Pa in the vacuum chamber. The evaporation opening 411 has a dimension of 300mm along the first direction. The vertical gap H between the adjustable baffle 42 and the main roller 3 is 5mm. Aluminum wire with a diameter of φ1.8mm is used, and the wire feeding speed is 750mm / min for aluminum evaporation. The winding speed of the first roller 1 and the second roller 2 is 30m / min. The air blowing pipe 51 is set with 4 sections, and the air flow of each air blowing pipe 51 is 100sccm. The sheet resistance is monitored online, and the bonding force is measured offline.

[0051] Comparative Example 3

[0052] A roll-to-roll evaporation coating equipment is used, with a vacuum level of 5.0E-3Pa in the vacuum chamber. The evaporation opening 411 has a dimension of 300mm along the first direction. The vertical gap H between the adjustable baffle 42 and the main roller 3 is 5mm. Aluminum wire with a diameter of φ1.8mm is used, and the wire feeding speed is 650mm / min for aluminum evaporation. The winding speed of the first roller 1 and the second roller 2 is 30m / min. The air blowing pipe 51 is set with 4 sections, and the air flow of each air blowing pipe 51 is 50 / 100 / 100 / 50sccm respectively. The sheet resistance is monitored online, and the bonding force is measured offline.

[0053] Comparative Example 4

[0054] A roll-to-roll evaporation coating equipment is used, with a vacuum level of 5.0E-3Pa in the vacuum chamber. The evaporation opening 411 has a dimension of 300mm along the first direction. The vertical gap H between the adjustable baffle 42 and the main roller 3 is 5mm. Aluminum wire with a diameter of φ1.8mm is used, and the wire feeding speed is 650mm / min for aluminum evaporation. The winding speed of the first roller 1 and the second roller 2 is 30m / min. The air blowing pipe 51 is set with 4 sections, and the air flow of each air blowing pipe 51 is 0sccm. The sheet resistance is monitored online, and the bonding force is measured offline.

[0055] Comparative Example 5

[0056] The A10x bond film evaporation equipment is used, the vacuum degree of the vacuum chamber reaches 5.0E-2Pa, the evaporation opening 411 has a size of 300m along the first direction, the vertical gap H between the adjustable baffle 42 and the main roller 3 is 5mm, aluminum wire with a diameter of φ1.8mm is used, the wire feeding speed is 120mm / min, the total oxygen supply is 10000sccm, aluminum evaporation is carried out, the winding speed of the first roller 1 and the second roller 2 is 540m / min, the equipment monitors the base film transmittance rate as 85%, and after production is completed, the aluminum plating process is carried out.

[0057] The same winding evaporation coating equipment is used in the aluminum plating process. The vacuum degree reaches 5.0E-3Pa. The size of the evaporation opening 411 along the first direction is 300m. The gap H between the adjustable baffle 42 and the main roller 3 is 5mm. Aluminum wire with a diameter of φ1.8m is used and the wire feeding speed is 650mm / min for evaporation aluminum plating. The winding speed of the first roller 1 and the second roller 2 is 30m / min. At this time, no oxygen is introduced. The sheet resistance is monitored online, and the adhesion is measured offline.

[0058] In the above two embodiments and five comparative production, the eddy current method was used to test the sheet resistance value, and the measurement positions were divided into four according to the position of the air blowing pipe 51; the bonding force of the composite current collector was tested using the bonding force test method specified in GB / T 2792-2014.

[0059] Specifically, in eddy current testing, when a detection coil carrying alternating current approaches a conductive material, the alternating magnetic field generated by the coil induces a closed loop current, i.e., an eddy current, within the material. The secondary magnetic field generated by the eddy current reacts on the detection coil, causing a change in the coil's impedance (including inductance and resistance). By measuring this impedance change, the sheet resistance of the material can be indirectly derived, where R = (ρ / d), ρ is the resistivity of the material, and d is the thickness of the film to be tested.

[0060]

[0061] The comparison results are as follows:

[0062] Example 1 is compared with Comparative Examples 4 and 5 to illustrate the application of the preparation method and apparatus of the composite current collector. The composite current collector obtained by one-time vapor deposition, compared with the composite current collector obtained by first vapor deposition of an alumina layer and then vapor deposition of a metal aluminum layer, maintains the original required bonding force between the metal aluminum layer and the base film. The obtained alumina layer can effectively enhance the bonding force of the composite current collector. At the same time, since no turnover process is used, the storage cost and vacuum drying cost are reduced. For a factory with an annual production of 5 million square meters of composite current collector, 0.5 yuan can be saved per square meter, and the actual cost reduction is about 2.5 million yuan per year.

[0063] Comparing Example 1 with Comparative Example 1, and Example 2 with Comparative Example 2, the amount of oxygen purging affects the bonding force of the composite current collector and the sheet resistance of the composite metal layer. Excessive oxygen purging affects the vacuum level of the vacuum chamber, causing a decrease in the bonding force of the aluminum metal layer and the formation of a thicker oxide metal layer, resulting in a thinner composite metal layer, which in turn affects the sheet resistance value. That is, the oxygen purging flow rate can be controlled based on the monitoring of the online sheet resistance value, thereby controlling the thickness of the oxide metal layer.

[0064] Compared with Comparative Example 3, different wire feeding speeds require different parameter conditions to obtain composite current collectors with higher bonding force; specifically, the faster the wire feeding speed, the higher the required oxygen purging flow rate.

[0065] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A composite current collector post making apparatus characterized by, include: A vacuum chamber, wherein a first roller (1) and a second roller (2) are spaced apart along a first direction, and a main roller (3) is disposed between the first roller (1) and the second roller (2). The first roller (1) is used to unwind the base film (10), the second roller (2) is used to rewind the base film (10), and the main roller (3) is used to support the base film (10) downward. A shielding assembly (4) is disposed in the vacuum chamber. The shielding assembly (4) includes a main shielding plate (41) and an adjustable baffle (42). The evaporation opening (411) of the main shielding plate (41) is located directly below the main roller (3). The adjustable baffle (42) is vertically disposed on the upper surface of the main shielding plate (41). The adjustable baffle (42) is located at one end of the evaporation opening (411) along the first direction near the first roller (1). A metal vapor evaporation apparatus for injecting metal vapor into the vacuum chamber through the evaporation opening (411); An oxygen supply device (5) is provided at one end of the adjustable baffle (42) away from the evaporation opening (411) along the first direction. The oxygen supply device (5) is used to purge oxygen to the bottom wall of the base membrane (10).

2. The composite current collector post-production device of claim 1, wherein, The flow rate of the purging oxygen ranges from 100 sccm to 1000 sccm.

3. The composite current collector post-production device of claim 2, wherein, The oxygen supply device (5) includes several air blowing pipes (51) extending along the second direction and connected end to end, and each air blowing pipe (51) is provided with a purge hole for purging oxygen.

4. The composite current collector post-production device of claim 3, wherein, The air blowing pipe (51) is equipped with a mass flow meter (52), which is used to monitor the oxygen flow rate in the air blowing pipe (51).

5. The composite current collector post-production device of any one of claims 1-4, wherein, The top wall of the main shield (41) is provided with a cooling pipe (6), which surrounds the evaporation opening (411) and is used for heat exchange with metal vapor.

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