Current collector module and preparation method thereof, electrode plate and battery

Abstract

The invention relates to a current collector module and a preparation method thereof, an electrode plate and a battery. The preparation method comprises the following steps: providing a current collector; performing plasma activating treatment on the surface of the current collector; and depositing a bonding enhancement layer on the surface of the current collector subjected to plasma activation treatment to obtain a current collector module, wherein the thickness of the bonding enhancement layer is less than 1 [mu] m. The current collector module prepared by the preparation method of the current collector module provided by the invention has relatively good bonding performance, and can effectively bond the active material layer, so that the electrode plate has relatively good use performance.

Description

Current collector module and its preparation method, electrode plates and battery Technical Field

[0001] This application relates to the field of lithium-ion battery technology, specifically to a current collector module and its preparation method, electrode sheets and battery. Background Technology

[0002] In the manufacturing process of lithium batteries, the adhesion between the current collector module and the active material coating is one of the key factors affecting battery performance. Good adhesion prevents the active material from detaching from the current collector module during cycling, thereby improving cycle life, safety, and rate performance. As battery cells are designed with higher discharge capabilities, the surface density of the active material coating is decreasing, leading to a reduction in the adhesion between the current collector module and the active coating, and potentially causing the active coating to detach. Therefore, improving the adhesion of the current collector module is a problem that urgently needs to be solved. Summary of the Invention

[0003] In view of this, this application provides a current collector module and its preparation method, electrode sheet and battery. The current collector module prepared by the current collector module preparation method provided in this application has good bonding performance and can effectively bond the active material layer, so that the electrode sheet has good performance.

[0004] This application provides a method for preparing a current collector module, the method comprising: providing a current collector; performing plasma activation treatment on the surface of the current collector; and depositing a bonding reinforcement layer on the surface of the current collector after plasma activation treatment to obtain a current collector module; wherein the thickness of the bonding reinforcement layer is less than 1 μm.

[0005] Furthermore, the plasma activation treatment of the current collector surface includes: introducing a treatment gas into the current collector surface, the treatment gas including at least one of oxygen and nitrogen or argon.

[0006] Furthermore, the volume percentage α of oxygen in the processed gas is in the range of 50% ≤ α ≤ 66.7%.

[0007] Furthermore, in the plasma activation treatment, at least one of the following conditions is met: the gas pressure P of the treatment gas is in the range of 10Pa≤P≤1000Pa; the treatment time t of the surface of the current collector is in the range of 5s≤t≤300s.

[0008] Furthermore, in the plasma activation treatment, at least one of the following conditions is met: the range of the gas pressure P of the treatment gas is 400Pa≤P≤600Pa; and the range of the treatment time t of the surface of the current collector is 100s≤t≤200s.

[0009] Furthermore, the surface of the current collector is subjected to plasma activation treatment using a plasma treatment device, wherein the output power of the plasma treatment device ranges from 100W to 200W.

[0010] Furthermore, the thickness d of the bonding reinforcement layer is in the range of 5nm ≤ d ≤ 200nm.

[0011] Furthermore, the thickness d of the bonding reinforcement layer is in the range of 50nm≤d≤150nm.

[0012] Furthermore, the type of the bonding reinforcement layer includes at least one of silicon-based materials, metal oxides, nitrides, and carbon-based materials.

[0013] Furthermore, the type of the bonding reinforcement layer includes at least one of silicon dioxide, aluminum oxide, silicon nitride, and diamond-like carbon.

[0014] This application provides a current collector module, which is prepared by the preparation method provided in this application. The current collector module includes a current collector and an adhesive reinforcement layer, wherein the adhesive reinforcement layer is disposed on the surface of the current collector and the thickness of the adhesive reinforcement layer is less than 1 μm.

[0015] This application provides an electrode sheet, which includes: a current collector module and an active material layer provided in this application, wherein the active material layer is disposed on the surface of the bonding reinforcement layer.

[0016] This application provides a battery, which includes a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode and / or the negative electrode are the electrode plates provided in this application.

[0017] In the method for preparing the current collector module provided in this application, plasma activation treatment is applied to the surface of the current collector to effectively clean the surface and introduce a large number of polar functional groups such as hydroxyl and carboxyl groups without damaging the current collector, thereby significantly improving the surface energy and chemical activity of the current collector. Furthermore, a bonding reinforcement layer is deposited on the surface of the current collector after plasma activation treatment. This nanoscale bonding reinforcement layer forms a strong chemical bond with the activated surface of the current collector. In addition, when the current collector module is applied to the electrode sheet, the bonding reinforcement layer is positioned away from the surface of the current collector to accommodate the active material layer, providing an excellent adhesion interface for the active material layer. The method for preparing the current collector module provided in this application significantly improves the bonding performance of the current collector module through the synergistic effect of "plasma activation treatment" and "depositing a bonding reinforcement layer with a thickness at the nanoscale." When the current collector module is applied to the electrode sheet, it exhibits good adhesion to the active material layer, reducing the interfacial resistance between them and improving the rate performance and cycle performance of the battery when the electrode sheet is used. Furthermore, the thickness of the bonding reinforcement layer is less than 1 μm, which minimizes the increase in the internal resistance of the current collector module and enhances its performance. Moreover, the preparation method provided in this application can be added as an independent process to existing electrode sheet manufacturing production lines, facilitating large-scale application and providing practical guidance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the implementation will be briefly introduced below. Obviously, the drawings described below are some implementations of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 is a flowchart illustrating the preparation method of a current collector module according to an embodiment of this application; Figure 2 is a partial cross-sectional structural diagram of a current collector module according to an embodiment of this application; Figure 3 is a structural diagram of an electrode sheet according to an embodiment of this application.

[0020] Explanation of reference numerals in the attached drawings: 100-current collector module, 110-current collector, 120-bonding reinforcement layer, 200-electrode plate, 210-active material layer. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method of preparation, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods of preparation, products, or apparatuses.

[0023] In this document, references to "embodiment" or "implementation" mean that a particular feature, structure, or characteristic described in connection with an embodiment or implementation may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] In the manufacturing process of lithium batteries, the adhesion between the current collector module and the active material coating is one of the key factors affecting battery performance. Good adhesion prevents the active material from detaching from the current collector module during cycling, thereby improving cycle life, safety, and rate performance. As battery cells are designed with higher discharge capabilities, the surface density of the active material coating is decreasing, leading to a reduction in the adhesion between the current collector module and the active coating, and potentially causing the active coating to detach. Therefore, improving the adhesion of the current collector module is a problem that urgently needs to be solved.

[0025] Please refer to Figures 1 to 3. This application provides a method for preparing a current collector module 100. The preparation method includes: S101, providing a current collector 110.

[0026] S102, the surface of the current collector 110 is subjected to plasma activation treatment.

[0027] Understandably, in the terminology of this application, the plasma is a macroscopically electrically neutral ionized gas composed of a large number of charged particles (ions, electrons) and neutral particles (atoms, molecules).

[0028] Understandably, plasma activation treatment of the surface of the current collector 110 refers to the process by which plasma, such as energetic ions, electrons, and neutral particles, driven by an electric field or thermal motion, impacts the surface of the foil at a high speed. This impact produces a "sputtering" effect, which on the one hand further removes impurities such as oil, oxides, or dust from the surface of the current collector 110; on the other hand, it forms tiny uneven structures on the surface of the current collector 110, increasing the surface roughness; furthermore, a large number of active free radicals exist in the plasma, which can introduce active groups such as hydroxyl and carboxyl groups onto the surface of the current collector 110, thereby changing the chemical properties of the surface of the current collector 110.

[0029] S103, deposit a bonding reinforcement layer 120 on the surface of the current collector 110 after plasma activation treatment to obtain the current collector module 100; wherein the thickness of the bonding reinforcement layer 120 is less than 1 μm.

[0030] Understandably, the thickness of the adhesive reinforcement layer 120 is at the nanometer level.

[0031] Understandably, the current collector module 100 prepared by the current collector module 100 preparation method provided in this application includes the current collector 110 and the bonding reinforcement layer 120, wherein the bonding reinforcement layer 120 is disposed on the surface of the current collector 110.

[0032] Understandably, the current collector module 100 is applied to the electrode plate 200, which further includes an active material layer 210 disposed on the surface of the bonding reinforcement layer 120.

[0033] In the fabrication method of the current collector module 100 provided in this embodiment, the surface of the current collector 110 is subjected to plasma activation treatment to effectively clean the surface of the current collector 110 and introduce a large number of polar functional groups such as hydroxyl and carboxyl groups without damaging the current collector 110, thereby significantly improving the surface energy and chemical activity of the current collector 110. Furthermore, a bonding reinforcement layer 120 is deposited on the surface of the current collector 110 after plasma activation treatment. The nanoscale bonding reinforcement layer 120 can form a strong chemical bond with the surface of the activated current collector 110. In addition, when the current collector module 100 is applied to the electrode plate 200, the bonding reinforcement layer 120 is positioned away from the surface of the current collector 110 to provide the active material layer 210, and the bonding reinforcement layer 120 provides an excellent adhesion interface for the active material layer 210. The method for preparing the current collector module 100 provided in this application significantly improves the bonding performance of the current collector module 100 through the synergistic effect of "plasma activation treatment" and "deposition of a bonding reinforcement layer 120 with a thickness at the nanometer level". When the current collector module 100 is applied to the electrode sheet 200, there is good bonding performance between the current collector module 100 and the active material layer 210, reducing the interfacial internal resistance between the current collector module 100 and the active material layer 210, and improving the rate performance and cycle performance of the battery when the electrode sheet 200 is applied. Furthermore, the thickness of the bonding reinforcement layer 120 is less than 1 μm, which is extremely thin and can minimize the increase in the internal resistance of the current collector module 100, thereby improving the performance of the current collector module 100. Moreover, the preparation method provided in this application can be added as an independent process to the existing electrode sheet 200 manufacturing production line, making it easy to achieve large-scale application and providing practical guidance.

[0034] Optionally, in a specific embodiment, compared to the scheme of directly coating the active material layer 210 on the surface of the current collector 110, when the current collector module 100 prepared by the preparation method provided in this application is applied to the electrode sheet 200, the peel strength between the current collector module 100 and the active material layer 210 is increased by more than 50%, and can even reach 100% to 200%, that is, the bonding reinforcement layer 120 and the active material layer 210 have better bonding performance.

[0035] Optionally, in some embodiments, the current collector 110 includes at least one of aluminum foil and copper foil.

[0036] Optionally, providing the current collector 110 further includes surface cleaning of the current collector 110. By cleaning the surface of the current collector 110, impurities such as oil, oxides, or dust are removed from the surface of the current collector 110. By eliminating impurities on the surface of the current collector 110, uniform deposition of the subsequent bonding reinforcement layer 120 can be ensured, thereby improving the uniformity and bonding performance of the current collector module 100 prepared by the preparation method for improving the bonding strength of the current collector module 100.

[0037] Optionally, the method of depositing the bonding reinforcement layer 120 on the surface of the current collector 110 includes at least one of physical deposition method and chemical deposition method.

[0038] Compared to directly coating the surface of the current collector 110 with an adhesive layer, in this embodiment, an adhesive reinforcement layer 120 is deposited on the surface of the current collector 110 using physical deposition and chemical deposition methods. This results in a higher purity, thinner and denser adhesive reinforcement layer 120, stronger adhesion between the adhesive reinforcement layer 120 and the current collector 110, and ultimately, better adhesion performance of the current collector module 100. Specifically, by depositing the adhesive reinforcement layer 120 on the surface of the current collector 110 using physical deposition, materials such as silica and diamond-like carbon can be directly deposited on the surface of the current collector 110 in atomic / ionic form to form a thin film. The atoms / ions inside the adhesive reinforcement layer 120 diffuse and mix with the atoms / ions on the surface of the current collector 110, making the adhesive reinforcement layer 120 less likely to detach from the current collector 110, thus giving the current collector module 100 better adhesion performance. A bonding reinforcement layer 120 is deposited on the surface of the current collector 110 by chemical deposition. During the deposition process, the deposited material can chemically react with the surface of the current collector 110 and form stable covalent bonds at the interface between the current collector 110 and the bonding reinforcement layer 120, thereby strengthening the adhesion between the current collector 110 and the bonding reinforcement layer 120 and improving the bonding performance of the current collector module 100.

[0039] Optionally, the preparation method further includes curing or stabilizing the current collector module 100 for winding and later use.

[0040] In this embodiment, the current collector module 100 is cured or stabilized to give it better structural performance. After the active material layer 210 is coated on the surface of the current collector module 100, powder shedding from the electrode sheet 200 can be avoided during the winding, cutting, or slitting process, ensuring the uniformity of the electrode sheet 200.

[0041] Optionally, in some embodiments, the plasma activation treatment of the surface of the current collector 110 is performed on one surface of the current collector 110, so that in the current collector module 100 obtained by the preparation method, the number of layers of the bonding reinforcement layer 120 is one layer, and the bonding reinforcement layer 120 is disposed on one surface of the current collector 110.

[0042] Optionally, in some other embodiments, the plasma activation treatment of the surface of the current collector 110 is performed by sequentially performing plasma activation treatment on the two opposite surfaces of the current collector 110, so that in the current collector module 100 obtained by the preparation method, the number of the bonding reinforcement layer 120 is two, and the two bonding reinforcement layers 120 are respectively disposed on the two opposite surfaces of the current collector 110.

[0043] In some embodiments, the plasma activation treatment of the surface of the current collector 110 includes: introducing a treatment gas into the surface of the current collector 110, the treatment gas including at least one of oxygen and nitrogen or argon.

[0044] Understandably, during the plasma activation treatment of the surface of the current collector 110, the treatment gas is partially or completely ionized to form a large amount of plasma, such as energetic ions, electrons and neutral particles.

[0045] Understandably, the plasma is formed by the processing gas under preset power and preset pressure. The specific values ​​of the preset power and preset pressure are not limited here.

[0046] Optionally, in some embodiments, the processing gas includes oxygen and nitrogen; in other embodiments, the processing gas includes oxygen and argon.

[0047] In this embodiment, a processing gas, including oxygen, is introduced into the surface of the current collector 110. This oxygen, as a reactive gas, generates active particles such as oxygen free radicals and oxygen ions after plasma ionization. These particles react with residual hydrocarbons on the surface of the current collector 110 to generate polar functional groups such as hydroxyl (-OH) and carboxyl (-COOH). These polar functional groups can form hydrogen bonds or covalent bonds with the subsequently deposited bonding reinforcement layer 120, significantly improving the interfacial adhesion between the current collector 110 and the bonding reinforcement layer 120. This allows the bonding reinforcement layer 120 to fully exert its bonding effect on the active material layer 210, improving the bonding performance of the current collector module 100. Furthermore, the processing gas also includes nitrogen or argon, which dilutes the oxygen concentration in the processing gas to prevent excessive oxidation of the current collector 110 surface and increased interfacial resistance. The nitrogen and argon gases also perform nanoscale etching on the surface of the current collector 110 through high-energy physical bombardment, forming a rough microstructure and increasing the surface area. Simultaneously, argon or nitrogen plasma bombardment can break the dense structure of the passivation film on the surface of the current collector 110, exposing more active sites, which facilitates the subsequent introduction of functional groups by oxygen plasma. Furthermore, nitrogen plasma can introduce nitrogen-containing functional groups such as amino (-NH2) onto the surface of the current collector 110, further enriching the types of surface active groups, improving the interfacial compatibility between the current collector 110 and the nitrogen-containing bonding reinforcement layer 120, and further enhancing the bonding performance of the current collector module 100.

[0048] Optionally, in some embodiments, the volume percentage α of oxygen in the processed gas is in the range of 50% ≤ α ≤ 66.7%.

[0049] Specifically, the volume percentage α of oxygen in the processed gas can be, but is not limited to, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, and 66.7%.

[0050] In this embodiment, when the volume percentage α of oxygen in the processing gas is within the range of 50% ≤ α ≤ 66.7%, the volume of oxygen in the processing gas is within a reasonable range. Similarly, the volume of nitrogen or argon is also within a reasonable range, so that nitrogen or argon can form a sufficient number of active sites on the surface of the current collector 110. This facilitates the formation of a sufficient number of polar functional groups such as hydroxyl (-OH) and carboxyl (-COOH) groups on the surface of the current collector 110, thereby significantly improving the interfacial adhesion between the current collector 110 and the bonding reinforcement layer 120. This allows the bonding reinforcement layer 120 to fully exert its bonding effect on the active material layer 210, improving the bonding performance of the current collector module 100. When the volume percentage α of oxygen in the processing gas is too large, the corresponding volume percentage of nitrogen or argon is too small. The active sites formed by the volume of nitrogen or argon on the surface of the current collector 110 are smaller, increasing the difficulty for oxygen to form polar functional groups on the surface of the current collector 110. When the volume percentage α of oxygen in the processed gas is too small, the number of polar functional groups formed by oxygen on the surface of the current collector 110 is small, making it difficult to bond tightly with the subsequently deposited bonding reinforcement layer 120, thus reducing the bonding performance of the current collector module 100.

[0051] Understandably, hydrocarbon organic matter inevitably remains on the surface of current collector 110, and the oxygen plasma combines with hydrogen free radicals in the hydrocarbon organic matter to form hydroxyl groups.

[0052] Understandably, hydrocarbon organic matter inevitably remains on the surface of current collector 110. The active particles in the oxygen plasma first oxidize the hydrocarbon organic matter on the surface of current collector 110 into hydroxyl and carbonyl functional groups. The active particles continue to bombard and cause the carbonyl and hydroxyl groups to combine further, eventually forming carboxyl groups.

[0053] In some embodiments, at least one of the following conditions is met in the plasma activation treatment: the pressure P of the treatment gas is in the range of 10 Pa ≤ P ≤ 1000 Pa.

[0054] Specifically, the value of the gas pressure P of the processed gas can be, but is not limited to, 10Pa, 30Pa, 50Pa, 80Pa, 100Pa, 110Pa, 130Pa, 150Pa, 180Pa, 200Pa, 220Pa, 250Pa, 300Pa, 350Pa, 380Pa, 400Pa, 450Pa, 500Pa, 520Pa, 550Pa, 600Pa, 640Pa, 700Pa, 750Pa, 800Pa, 850Pa, 900Pa, 920Pa, 950Pa, and 1000Pa.

[0055] In this embodiment, when the pressure P of the processing gas meets the range of 10 Pa ≤ P ≤ 1000 Pa, the pressure of the processing gas is within a reasonable range, which allows active particles in the plasma, such as oxygen ions, nitrogen ions, or argon ions, to diffuse uniformly in the cavity of the plasma processing equipment and to fully contact the surface of the current collector 110. This also gives the plasma high activity, as the plasma bombards the surface of the current collector 110 with uniform energy, introducing an appropriate amount of polar functional groups onto the surface of the current collector 110 and forming a morphology with uniform micro-roughness. During the subsequent deposition of the bonding reinforcement layer 120, the bonding reinforcement layer 120 and the current collector 110 are bonded together chemically, while the uniform rough surface morphology achieves mechanical interlocking, improving the interfacial bonding strength and stability between the current collector 110 and the bonding reinforcement layer 120, and ultimately giving the current collector module 100 better bonding performance. When the pressure of the processing gas is too high, the concentration of processing gas molecules is too high, and frequent particle collisions lead to rapid decay of particle energy. This significantly reduces the activity of the plasma, making it difficult to effectively etch the current collector 110 and introduce polar functional groups onto its surface. This weakens the chemical bonding between the current collector 110 and the subsequently deposited bonding reinforcement layer 120, resulting in poor adhesion between them. Conversely, when the pressure of the processing gas is too low, the processing gas molecules are too sparse, and the probability of particle collisions is extremely low. This makes it difficult to form a continuous and stable plasma, thus hindering the formation of sufficient polar functional groups on the surface of the current collector 110. This weakens the chemical bonding between the current collector 110 and the subsequently deposited bonding reinforcement layer 120, resulting in poor adhesion between them.

[0056] More preferably, in some embodiments, at least one of the following conditions is met during the plasma activation treatment: the pressure P of the treatment gas is in the range of 400 Pa ≤ P ≤ 600 Pa, so that the pressure range of the treatment gas is more reasonable, the active particles in the plasma can make more sufficient contact with the surface of the current collector 110, and at the same time, the plasma has higher activity. The plasma bombards the surface of the current collector 110 with uniform energy and introduces an appropriate amount of polar functional groups on the surface of the current collector 110, while forming a morphology with uniform micro-roughness. When the bonding reinforcement layer 120 is subsequently deposited, the current collector 110 and the bonding reinforcement layer 120 have higher interfacial bonding strength and stability, and ultimately the current collector module 100 has better bonding performance.

[0057] Specifically, the value of the gas pressure P of the processed gas can be, but is not limited to, 400Pa, 410Pa, 420Pa, 430Pa, 440Pa, 450Pa, 460Pa, 480Pa, 490Pa, 500Pa, 520Pa, 530Pa, 550Pa, 560Pa, 580Pa, 590Pa, and 600Pa.

[0058] In some embodiments, the time t for processing the surface of the current collector 110 is in the range of 5s ≤ t ≤ 300s.

[0059] Specifically, the time t for processing the surface of the current collector 110 can be, but is not limited to, 5s, 10s, 20s, 50s, 80s, 100s, 120s, 150s, 160s, 180s, 200s, 210s, 250s, 280s, and 300s.

[0060] In this embodiment, when the treatment time t of the current collector 110 is within the range of 5s ≤ t ≤ 300s, the treatment time t is within a reasonable range. The ions, free radicals, and other active particles in the plasma can perform preliminary oxidation and decomposition of organic impurities on the surface of the current collector 110, while simultaneously achieving physical etching and the introduction of polar functional groups. This effectively improves the surface properties of the current collector 110, resulting in a tight bond between the current collector 110 and the bonding reinforcement layer 120, and further enabling the bonding reinforcement layer 120 to tightly bond to the active material layer 210. The current collector module 100 exhibits good bonding performance. However, if the treatment time of the current collector 110 is too long, the plasma formed by the treatment gas may cause local thinning or perforation of the current collector 110 after continuous bombardment, affecting its mechanical and electrical properties. Furthermore, excessive polar functional groups formed by the plasma on the surface of the current collector 110 may lead to excessive thickness or uneven thickness of the bonding reinforcement layer 120 during subsequent deposition, increasing the internal resistance of the current collector module 100. When the current collector module 100 is applied to the electrode sheet 200 and assembled into a battery, it actually reduces the battery's cycle performance and rate performance. If the surface treatment time of the current collector 110 is too short, the plasma formed by the treatment gas cannot fully contact the current collector 110, making it difficult to form sufficient polar functional groups on the surface of the current collector 110 and to achieve a uniform micro-rough morphology on the surface of the current collector 110. During the subsequent deposition of the bonding reinforcement layer 120, the interfacial chemical bonding force and mechanical interlocking between the current collector 110 and the bonding reinforcement layer 120 will be significantly weakened, reducing the bonding performance of the current collector module 100.

[0061] More preferably, in some embodiments, the treatment time t of the surface of the current collector 110 is in the range of 100s≤t≤200s, so that the treatment time of the surface of the current collector 110 is more reasonable. The active particles such as ions and free radicals in the plasma can fully perform preliminary oxidation and decomposition of organic impurities on the surface of the current collector 110, while realizing physical etching and the introduction of polar functional groups, so as to further improve the surface performance of the current collector 110. The current collector 110 and the bonding reinforcement layer 120 have higher bonding performance, and the bonding reinforcement layer 120 can be tightly bonded to the active material layer 210, so that the current collector module 100 has better bonding performance.

[0062] Specifically, the value of the time t for processing the surface of the current collector 110 can be, but is not limited to, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, and 200s.

[0063] In some embodiments, the surface of the current collector 110 is subjected to plasma activation treatment by a plasma treatment device, wherein the output power of the plasma treatment device ranges from 100W to 200W.

[0064] Understandably, the output power of the plasma processing device is the output power that excites the processing gas to form the plasma.

[0065] Specifically, the output power of the plasma processing device can be, but is not limited to, 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W, and 200W.

[0066] In this embodiment, when the output power of the plasma processing device is within the range of 100W to 200W, the output power of the plasma processing device is within a reasonable range. The plasma processing device can output sufficient energy to ionize the processing gas into plasma and bombard the surface of the current collector 110 with uniform energy. At the same time, an appropriate amount of polar functional groups are introduced into the surface of the current collector 110 to facilitate the formation of chemical bonds and tight connection with the subsequently deposited bonding reinforcement layer 120. When the output power of the plasma processing device is too high, after the processing gas is ionized to form plasma, the energy of the active particles in the plasma increases significantly. This will continuously bombard the current collector 110, causing local thinning or perforation of the current collector 110 and affecting the electrical performance of the current collector 110. Furthermore, the plasma introduces excessive polar functional groups onto the surface of the current collector 110, resulting in an excessively thick bonding reinforcement layer 120 during subsequent deposition. This significantly increases the electron transport resistance between the current collector 110 and the active material layer 210, increasing the internal resistance of the current collector module 100 when applied to the electrode plate 200, thus degrading the performance of the current collector module 100. When the output power of the plasma processing equipment is too low, the energy of the active particles in the plasma after ionization of the processing gas is low, making it difficult to introduce polar functional groups onto the surface of the current collector 110 and to construct a uniform micro-rough morphology on the surface of the current collector 110. During the subsequent deposition of the bonding reinforcement layer 120, the interfacial chemical bonding and mechanical interlocking between the current collector 110 and the bonding reinforcement layer 120 are significantly weakened, reducing the bonding performance of the current collector module 100.

[0067] In some embodiments, the thickness d of the bonding reinforcement layer 120 is in the range of 5nm ≤ d ≤ 200nm. The bonding reinforcement layer 120 has better adhesion to both the current collector 110 and the active material layer 210, thereby improving the performance of the current collector module 100.

[0068] Specifically, the thickness d of the bonding reinforcement layer 120 can be, but is not limited to, 5nm, 8nm, 10nm, 20nm, 30nm, 50nm, 60nm, 80nm, 100nm, 110nm, 120nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, and 200nm.

[0069] In this embodiment, when the thickness d of the bonding reinforcement layer 120 satisfies the range of 5nm ≤ d ≤ 200nm, the thickness of the bonding reinforcement layer 120 is within a reasonable range. On the one hand, the bonding reinforcement layer 120, with a thickness at the nanometer level, can form chemical bonds and mechanical interlocks at the contact interface with the current collector 110, thereby improving the bonding performance between the bonding reinforcement layer 120 and the current collector 110. Simultaneously, it ensures the bonding effect of the bonding reinforcement layer 120 on the active material layer 210, preventing the active material layer 210 from detaching from the current collector module 100 or shedding powder, thus ensuring the uniformity of the electrode plate 200. On the other hand, it avoids the bonding reinforcement layer 120 from increasing the internal resistance of the electrode plate 200 or reducing the energy density of the electrode plate 200 due to excessive thickness, ensuring that the electrode plate 200 has good performance. When the electrode plate 200 is applied to a battery, the battery has high energy density and cycle performance. When the thickness of the bonding reinforcement layer 120 is too large, its conductivity is worse than that of the current collector 110. Consequently, when the current collector module 100 is applied to the electrode plate 200, it significantly increases the electron transport resistance between the current collector 110 and the active material layer 210, increasing the internal resistance of the current collector module 100 when applied to the electrode plate 200, thus degrading the performance of the current collector module 100. Furthermore, during drying, rolling, and cycling processes, an excessively thick bonding reinforcement layer 120 is prone to internal stress due to the difference in thermal expansion coefficients with the current collector 110. This makes the bonding reinforcement layer 120 more susceptible to cracking and delamination from the current collector 110, making it difficult to guarantee the bonding performance of the current collector module 100. When the thickness of the bonding reinforcement layer 120 is too small, an excessively thin bonding reinforcement layer 120 cannot completely cover the microscopic defects and active sites on the surface of the current collector 110, making it difficult to form a continuous and dense bonding interface. Not only are the chemical bonding and mechanical engagement with the current collector 110 limited, but the subsequent coating of the active material layer 210 also cannot be effectively connected. When the electrode plate 200 is applied to a battery, the active material layer 210 is prone to detachment and peeling due to volume expansion during the charge and discharge cycle of the battery, shortening the cycle life of the battery.

[0070] Preferably, in some embodiments, the thickness d of the bonding reinforcement layer 120 is in the range of 50nm≤d≤150nm, so that the thickness of the bonding reinforcement layer 120 is within a more reasonable range. The bonding reinforcement layer 120 can form a more stable chemical bond and mechanical interlock at the contact interface with the current collector 110, so as to further improve the bonding performance between the bonding reinforcement layer 120 and the current collector 110. At the same time, it can further ensure the bonding effect of the bonding reinforcement layer 120 on the active material layer 210, so as to prevent the active material layer 210 from falling off or shedding powder from the current collector module 100, and ensure the uniformity of the electrode sheet 200.

[0071] Specifically, the thickness d of the adhesive reinforcement layer 120 can be, but is not limited to, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, and 150nm.

[0072] In some embodiments, the adhesive reinforcement layer 120 includes at least one of silicon-based materials, metal oxides, nitrides, and carbon-based materials.

[0073] Understandably, the bonding force of the bonding reinforcement layer 120 to the active material layer 210 is greater than the bonding force of the current collector 110 to the active material layer 210.

[0074] In this embodiment, when the bonding reinforcement layer 120 includes a silicon-based material, its molecular structure is rich in silanol groups, which can form hydrogen bonds or dehydration condensation to form covalent bonds with the polar functional groups such as hydroxyl and carboxyl groups on the surface of the current collector 110. This allows the bonding reinforcement layer 120 to be firmly anchored to the surface of the current collector 110, and the bonding strength between the bonding reinforcement layer 120 and the current collector 110 is much higher than that of simple physical adsorption. In addition, the active material layer 210 includes an active material, and the surface of the active material also has hydroxyl or oxygen-containing defect sites. The silanol groups can also form hydrogen bonds or covalent bonds with the hydroxyl or oxygen-containing defect sites on the surface of the negative electrode active material (such as graphite, silicon-carbon negative electrode, lithium titanate), which is equivalent to building a "molecular bridge" between the current collector 110 and the active material layer 210, greatly reducing the connection impedance between the current collector module 100 and the active material layer 210, and effectively suppressing the shedding of the active material during charge and discharge cycles.

[0075] When the bonding reinforcement layer 120 includes a metal oxide, the surface of the metal oxide is rich in hydroxyl groups, which can form hydrogen bonds or dehydration condensation to form covalent bonds with the polar functional groups such as hydroxyl and carboxyl groups on the surface of the current collector 110, such as Si-O-Al. At the same time, the metal oxide particles can fill the microscopic depressions on the surface of the current collector 110, forming a mechanical interlocking effect. The bonding strength between the current collector 110 and the bonding reinforcement layer 120 is improved through both chemical and physical bonding. Meanwhile, the active material layer 210 includes an active material, and the surface of the active material also has hydroxyl or oxygen-containing defect sites. The metal oxide can form hydrogen bonds or covalent bonds with the active material in the active material layer 210, thereby effectively bonding the active material layer 210. Ultimately, this results in the current collector module 100 having better bonding performance after being applied to the electrode plate 200, avoiding phenomena such as powder shedding from the electrode plate 200, and improving the uniformity of the electrode plate 200.

[0076] When the type of the bonding reinforcement layer 120 is selected from nitrides, nitrogen-containing groups such as amino groups will remain on its surface during the preparation process. These groups can undergo acid-base reactions or dehydration condensation with polar functional groups such as carboxyl and hydroxyl groups on the surface of the current collector 110 to form covalent bonds. At the same time, amino groups can also form hydrogen bonds with polar sites on the surface of the active material layer 210. This results in good bonding stability between the bonding reinforcement layer 120 and the current collector 110, and between the bonding reinforcement layer 120 and the active material layer 210, ultimately giving the electrode sheet 200 good performance.

[0077] When the bonding reinforcement layer 120 is selected from carbon-based materials, the surface of the carbon-based material has polar groups such as carboxyl and hydroxyl groups, which can form chemical bonds with the polar functional groups on the surface of the current collector 110. In addition, when the electrode sheet 200 is a negative electrode sheet, the active material layer 210 includes active materials such as graphite, hard carbon, or soft carbon. The bonding reinforcement layer 120 can form a π-π stacking effect with the conjugated structure of graphite, hard carbon, or soft carbon in the active material layer 210, so as to significantly improve the interfacial affinity and adhesion between the bonding reinforcement layer 120 and the active material layer 210, and ultimately make the bonding reinforcement layer 120 and the current collector 110, and the bonding reinforcement layer 120 and the active material layer 210 have good bonding stability, and the electrode sheet 200 has good performance.

[0078] Understandably, in the terminology of this application, the phenomenon of powder shedding from the electrode 200 refers to the phenomenon of active material falling off from the active material layer 210 of the electrode 200.

[0079] In some embodiments, the type of the bonding reinforcement layer 120 includes at least one of silicon dioxide, aluminum oxide, silicon nitride, and diamond-like carbon.

[0080] In this embodiment, when the type of the bonding reinforcement layer 120 includes at least one of silicon dioxide, aluminum oxide, silicon nitride, and diamond-like carbon, the bonding reinforcement layer 120 can form effective chemical bonds with the polar functional groups on the surface of the current collector 110. At the same time, the bonding reinforcement layer 120 and the active material layer 210 have a large interfacial affinity and adhesion, thereby enabling the current collector module 100 to be applied to the electrode plate 200, and the electrode plate 200 to have good performance.

[0081] This application provides a current collector module 100, which is prepared by the preparation method provided in this application. The current collector module 100 includes a current collector 110 and an adhesive reinforcement layer 120. The adhesive reinforcement layer 120 is disposed on the surface of the current collector 110 and the thickness of the adhesive reinforcement layer 120 is less than 1 μm.

[0082] Understandably, the adhesive reinforcement layer 120 is stacked with the current collector 110.

[0083] In this embodiment, the current collector module 100 is obtained by the preparation method of the current collector module 100 provided in this application. The preparation method provided in this application significantly improves the bonding performance between the current collector 110 and the bonding reinforcement layer 120 in the current collector module 100 through the synergistic effect of "plasma activation treatment" and "deposition of a bonding reinforcement layer 120 with a thickness at the nanometer level". At the same time, when the current collector module 100 is applied to the electrode sheet 200, the bonding reinforcement layer 120 can form a strong bonding effect with the subsequently coated active material layer 210, reducing the interfacial internal resistance between the current collector module 100 and the active material layer 210, and improving the rate performance and cycle performance of the battery when the electrode sheet 200 is applied to the battery. Furthermore, the thickness of the bonding reinforcement layer 120 is less than 1 μm, in other words, the thickness of the bonding reinforcement layer 120 is at the nanometer level. This avoids occupying the space of the current collector module 100 along its thickness direction. When the current collector module 100 is applied to the electrode plate 200 and assembled in the battery, it can avoid increasing the internal resistance of the electrode plate 200 due to the excessive thickness of the bonding reinforcement layer 120. At the same time, it can avoid occupying the space of the active material layer 210 due to the excessive thickness of the current collector module 100, ensuring that the electrode plate 200 has a good energy density, and ultimately enabling the battery to have high rate performance and cycle performance.

[0084] This application provides an electrode sheet 200, which includes a current collector module 100 and an active material layer 210 provided in this application. The active material layer 210 is disposed on the surface of the bonding reinforcement layer 120.

[0085] Understandably, along the thickness direction of the electrode sheet 200, the current collector 110, the bonding reinforcement layer 120, and the active material layer 210 are sequentially stacked.

[0086] In this embodiment, the electrode 200 includes a current collector module 100 and an active material layer 210 provided in this application. The current collector 110 and the bonding reinforcement layer 120 within the current collector module 100 have good bonding strength. Simultaneously, the bonding reinforcement layer 120 can effectively bond with the active material layer 210, making it difficult for the active material layer 210 to detach from the current collector module 100, greatly reducing the phenomenon of powder shedding from the electrode 200. This also avoids excessive interfacial resistance of the electrode 200 due to insufficient bonding between the active material layer 210 and the current collector module 100. When the electrode 200 is applied to a battery, the battery exhibits good rate performance and cycle performance.

[0087] Optionally, in some embodiments, the active material layer 210 is a single layer, disposed on the side of the current collector module 100 where the bonding reinforcement layer 120 is located. In other embodiments, the active material layer 210 is a double layer, disposed on opposite sides of the current collector module 100.

[0088] This application provides a battery, which includes a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode and / or the negative electrode is the electrode 200 provided in this application.

[0089] Understandably, the positive electrode, the separator, and the negative electrode are stacked in sequence.

[0090] Understandably, the electrolyte is used to wet at least a portion of the electrode plates 200.

[0091] Optionally, in some embodiments, the positive electrode is the electrode 200 provided in this application, and the negative electrode is other conventional or unconventional electrode 200, which is not limited here. In other embodiments, the negative electrode is the electrode 200 provided in this application, and the positive electrode is other conventional or unconventional electrode 200, which is not limited here. In still other embodiments, both the positive electrode and the negative electrode are electrode 200 provided in this application.

[0092] In this embodiment, when the battery includes the electrode sheet 200 provided in this application, the current collector module 100 and the active material layer 210 in the electrode sheet 200 have a high bonding force. During the charging and discharging process of the battery, it can effectively suppress the pulverization, shedding, and interface peeling problems of the active material in the active material layer 210 caused by volume expansion and contraction, maintain the integrity of the conductive network of the electrode sheet 200, and reduce the increase in the internal resistance of the electrode sheet 200 during cycling. At the same time, the stable interface bonding can reduce the direct contact between the electrolyte and the current collector module 100, suppress the occurrence of side reactions such as corrosion of the current collector module 100 and excessive thickening of the passivation layer, thereby improving the cycle life and rate performance of the battery. In addition, the high bonding force can support the use of higher compaction density in the preparation process of the electrode sheet 200, increase the loading of active material in the electrode sheet 200, help improve the energy density of the battery, and ultimately enable the battery to maintain excellent performance stability and safety under high-rate charging and discharging, long-term cycling, and high and low temperature conditions, and the battery has good performance.

[0093] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form yet another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A method for preparing a current collector module, characterized in that, The preparation method includes: providing a current collector; performing plasma activation treatment on the surface of the current collector; and depositing a bonding reinforcement layer on the surface of the current collector after plasma activation treatment to obtain a current collector module; wherein the thickness of the bonding reinforcement layer is less than 1 μm.

2. The preparation method according to claim 1, characterized in that, The plasma activation treatment of the current collector surface includes: introducing a treatment gas into the current collector surface, the treatment gas including at least one of oxygen and nitrogen or argon.

3. The preparation method according to claim 2, characterized in that, The volume percentage α of oxygen in the processed gas is in the range of 50% ≤ α ≤ 66.7%.

4. The preparation method according to claim 2, characterized in that, In the plasma activation treatment, at least one of the following conditions must be met: the gas pressure P of the treatment gas is in the range of 10 Pa ≤ P ≤ 1000 Pa; the treatment time t of the surface of the current collector is in the range of 5 s ≤ t ≤ 300 s.

5. The preparation method according to claim 2, characterized in that, In the plasma activation treatment, at least one of the following conditions must be met: the gas pressure P of the treatment gas is in the range of 400Pa≤P≤600Pa; the treatment time t of the surface of the current collector is in the range of 100s≤t≤200s.

6. The preparation method according to claim 1, characterized in that, The surface of the current collector is activated by plasma treatment using a plasma treatment device, wherein the output power of the plasma treatment device ranges from 100W to 200W.

7. The preparation method according to any one of claims 1 to 6, characterized in that, The thickness d of the bonding reinforcement layer is in the range of 5nm≤d≤200nm.

8. The preparation method according to any one of claims 1 to 6, characterized in that, The thickness d of the bonding reinforcement layer is in the range of 50nm≤d≤150nm.

9. The preparation method according to any one of claims 1 to 6, characterized in that, The type of adhesive reinforcement layer includes at least one of silicon-based materials, metal oxides, nitrides, and carbon-based materials.

10. The preparation method according to any one of claims 1 to 6, characterized in that, The type of bonding reinforcement layer includes at least one of silicon dioxide, aluminum oxide, silicon nitride, and diamond-like carbon.

11. A current collector module, characterized in that, The current collector module is prepared by the preparation method according to any one of claims 1 to 10. The current collector module includes: a current collector; and an adhesive reinforcement layer disposed on the surface of the current collector, the thickness of the adhesive reinforcement layer being less than 1 μm.

12. An electrode sheet, characterized in that, The electrode sheet includes: the current collector module as described in claim 11; and an active material layer disposed on the surface of the bonding reinforcement layer.

13. A battery, characterized in that, The battery includes a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode and / or the negative electrode is the electrode as described in claim 12.

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