Plate-shaped anode plate for negative plate lithium supplementing process

Abstract

The invention relates to a plate-shaped anode plate for a negative plate lithium supplementing process, and belongs to the technical field of lithium supplementing, the plate-shaped anode plate is sequentially provided with an insulating layer, a conductive layer and a lithium source layer, the insulating layer comprises a T-shaped seat, a cable sealing seat and a conductive cable, the T-shaped seat is provided with a guide rail matched with lithium supplementing equipment, the conductive cable penetrates through the cable sealing seat and the T-shaped seat and is electrically connected with the conductive layer, and the conductive layer is electrically connected with the lithium source layer. The conductive layer comprises a conductive plate and a plurality of conductive columns, the conductive columns are fixedly embedded in the conductive plate in a matrix distribution manner, the working surfaces of the top ends of the conductive columns are in surface contact with the lithium source layer, and the lithium source layer is used for providing lithium ions in the electrochemical lithium supplementing process; a three-dimensional conductive network framework is formed by a plurality of conductive columns embedded in the conductive plate in a matrix manner, and current of the conductive plate is uniformly transmitted to the lithium source layer, so that the problem of non-uniform current distribution caused by an edge effect of a traditional plate electrode is fundamentally solved, and lithium ions are uniformly and synchronously dissolved from all parts of the lithium source layer; and the thickness consistency and the capacity consistency of lithium supplement are improved.

Description

Technical Field

[0001] This invention relates to the field of lithium replenishment technology, and more specifically, to a plate-shaped anode plate for lithium replenishment processes of negative electrode sheets. Background Technology

[0002] In the field of lithium-ion battery manufacturing, electrochemical lithium replenishment technology is a key process that involves constructing a temporary electrochemical system and using an applied current to replenish lithium ions from lithium metal to the negative electrode. In this process, the anode plate, as the core component, is the site where electrons from the external circuit are transferred to the electrolyte and oxidation occurs. Its performance directly determines the efficiency, uniformity, and energy consumption level of lithium replenishment.

[0003] To meet the integrated requirements of continuous lithium replenishment equipment, plate-shaped structures are widely adopted. However, traditional plate-shaped anode plates typically use a single, large-area, thick conductive plate as the current collector, which has significant drawbacks in practical applications: First, due to the edge effect, the current distribution on the plate surface is severely uneven, resulting in inconsistent lithium-ion dissolution rates. This leads to significant differences in lithium replenishment amounts in different areas of the negative electrode, affecting battery capacity consistency and even inducing the risk of localized lithium plating. Second, the overall structure is bulky, requiring multiple people to work together during installation and material replacement. The positioning and fastening steps are cumbersome, severely impacting production cycle and maintenance efficiency. Third, during continuous operation, the strip-shaped negative electrode is prone to slight vibration or deviation. Traditional structures lack an effective electrode spacing stabilization mechanism, and electrode spacing fluctuations cause changes in electric field strength, further exacerbating problems such as uneven lithium replenishment thickness and poor batch consistency, ultimately restricting the improvement of overall battery performance and yield.

[0004] Therefore, there is an urgent need to provide a plate-shaped anode plate for lithium replenishment process of negative electrode sheet that can simultaneously solve the problems of electric field uniformity, ease of installation and electrode spacing stability, so as to solve the above technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a plate-shaped anode plate for lithium replenishment process of negative electrode sheet, thereby solving the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A plate-shaped anode plate for lithium replenishment process of negative electrode sheet, wherein an insulating layer, a conductive layer and a lithium source layer are stacked in sequence; The insulating layer includes a T-shaped base, a cable sealing base, and a conductive cable. The top and bottom edges of the T-shaped base are provided with guide rails extending along its length. The guide rails are used to mate with corresponding slots on the frame of the lithium replenishment equipment. A cable channel is opened inside the T-shaped base. The cable channel has an entrance located on the side of the T-shaped base and an exit located on the upper surface of the T-shaped base. The cable sealing base is fixed at the entrance. The conductive cable passes through the cable sealing base and the cable channel in sequence, and extends out from the exit to be electrically connected to the conductive layer. The conductive layer includes a conductive plate and a plurality of conductive pillars. The conductive plate is fixed on the upper surface of the T-shaped base and covers the outlet of the cable channel. The plurality of conductive pillars are fixedly embedded in the interior of the conductive plate on the side away from the T-shaped base in a matrix distribution. The working surface of the top end of the conductive pillar passes through the conductive plate and forms a surface contact with the lithium source layer. The conductive pillars are electrically connected to the conductive plate and the lithium source layer respectively. The lithium source layer is fixed on the side of the conductive layer away from the insulating layer and covers the top working surface of the conductive pillar, and is used to provide lithium ions during the electrochemical lithium replenishment process.

[0007] As a preferred technical solution of the present invention, the conductive layer further includes at least one set of electrode spacing adjustment mechanisms for adjusting the distance between the negative electrode sheet and the anode plate. The electrode spacing adjustment mechanism includes a guide roller, a bearing, and a bearing seat. The bearing seat is fixed to the end of the conductive plate, and the guide roller is rotatably mounted on the bearing seat through the bearing.

[0008] As a preferred technical solution of the present invention, the pole pitch adjustment mechanism is provided in two sets, which are respectively arranged at the upper and lower ends of the conductive plate.

[0009] As a preferred technical solution of the present invention, the conductive plate and the plurality of conductive pillars are all made of copper.

[0010] As a preferred technical solution of the present invention, the cross-section of the guide rail is L-shaped, which matches the L-shaped slot on the frame of the lithium replenishment equipment.

[0011] As a preferred technical solution of the present invention, a first sealing ring is provided at the mating surface of the cable sealing seat and the T-shaped seat, and a second sealing ring is provided at the mating surface of the conductive plate and the T-shaped seat. As a preferred technical solution of the present invention, the lithium source layer is fixedly bonded to the conductive layer by compression bonding.

[0012] As a preferred technical solution of the present invention, the distribution density of the matrix-distributed conductive pillars in the edge region of the conductive plate is greater than the distribution density of the conductive pillars in the center region of the conductive plate.

[0013] As a preferred technical solution of the present invention, the distribution density of the conductive pillars increases in a stepwise manner from the central region of the conductive plate to its edge region.

[0014] In summary, compared with the prior art, the beneficial effects of the present invention are: This invention relates to a plate-shaped anode plate for lithium replenishment in negative electrode processes. Multiple conductive pillars are embedded in the conductive plate in a matrix to form a three-dimensional conductive network skeleton. This skeleton serves as multiple discrete and uniformly distributed vertical current output points, which uniformly transmit the current from the conductive plate to the entire lithium source layer. This fundamentally breaks the uneven current distribution caused by edge effects in traditional plate electrodes, ensuring that the current is uniformly applied to the entire working surface of the lithium source layer. This ensures that lithium ions dissolve uniformly and synchronously from all parts of the lithium source layer, improves the uniformity of lithium replenishment, and reduces the probability of lithium plating on the electrode. In addition, the positioning and guiding function of the guide roller provides a stable running track for the running negative electrode sheet, ensuring that the spacing between the negative electrode sheet and the lithium source layer of the anode plate remains constant throughout the lithium replenishment process. This reduces the probability of problems such as inconsistent or uneven lithium replenishment caused by slight deviation or shaking of the strip negative electrode sheet during continuous production, effectively improving battery performance and battery life. The lithium source layer is fixed on the conductive layer using a pressing and composite process. Under high pressure, the pressing process creates a tight mechanical bond and physical contact between the lithium source material and the working surface at the top of the conductive pillar, ensuring the mechanical strength of the lithium source layer and preventing it from falling off under vibration or stress. In addition, the huge pressure creates a large area of ​​low-resistance contact surface between the lithium source layer and the conductive pillar, ensuring the efficient execution of the lithium ionization process and the electron transport process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the plate-shaped anode plate used in the lithium replenishment process of the negative electrode sheet according to the present invention; Figure 2 This is a front view of the insulating layer of the present invention; Figure 3 This is an exploded view of the insulating layer of the present invention; Figure 4 This is a side view of the T-shaped seat of the present invention; Figure 5 for Figure 4 A magnified view of part C; Figure 6 This is a schematic diagram of the conductive plate of the present invention; Figure 7 This is an exploded view of the conductive plate of the present invention; Figure 8 This is a schematic diagram of the assembly of the plate-shaped anode plate used in the lithium replenishment process of the negative electrode sheet according to the present invention; Figure 9 for Figure 8AA cross-section view; Figure 10 for Figure 9 A magnified view of part B; Among them, 1-lithium source layer, 2-conductive layer, 21-conductive plate, 22-conductive column, 23-pole gap adjustment mechanism, 231-guide roller, 232-bearing, 233-bearing seat, 3-insulating layer, 31-T-shaped seat, 311-guide rail, 32-cable sealing seat, 33-conductive cable, 34-first sealing ring, 35-second sealing ring, 4-negative electrode sheet. Detailed Implementation

[0016] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for illustration and explanation only and are not intended to limit the present invention.

[0017] like Figures 1 to 10 As shown, a plate-shaped anode plate for lithium replenishment process of negative electrode sheet is provided with an insulating layer 3, a conductive layer 2 and a lithium source layer 1 stacked in sequence. The insulating layer 3 includes a T-shaped base 31, a cable sealing base 32, and a conductive cable 33. The top and bottom edges of the T-shaped base 31 are provided with guide rails 311 extending along its length. The guide rails 311 are used to cooperate with corresponding slots on the frame of the lithium replenishment equipment. A cable channel (not shown in the figure) is opened inside the T-shaped base 31. The cable channel has an entrance on the side of the T-shaped base 31 and an exit on the upper surface of the T-shaped base 31. The cable sealing base 32 is fixed at the entrance. The conductive cable 33 passes through the cable sealing base 32 and the cable channel in sequence, and extends out from the exit to be electrically connected to the conductive layer 2. The conductive layer 2 includes a conductive plate 21 and a plurality of conductive pillars 22. The conductive plate 21 is fixed on the upper surface of the T-shaped seat 31 and covers the outlet of the cable channel. The plurality of conductive pillars 22 are fixedly embedded in the interior of the conductive plate 21 on the side away from the T-shaped seat 31 in a matrix distribution. The top working surface of the conductive pillar 22 passes through the conductive plate 21 and forms a surface contact with the lithium source layer 1. The conductive pillars 22 are electrically connected to the conductive plate 21 and the lithium source layer 1 respectively. The lithium source layer 1 is fixed on the side of the conductive layer 2 away from the insulating layer 3 and covers the top working surface of the conductive pillar 22, and is used to provide lithium ions during the electrochemical lithium replenishment process.

[0018] Insulation layer 3 serves as the supporting framework for the anode plate, ensuring reliable insulation between the entire anode plate and the grounded equipment frame. Through a groove structure on its body, it achieves rapid and precise engagement with the lithium replenishment equipment frame, providing stable mechanical fixation and reference positioning for the entire anode plate. Furthermore, due to the insulating properties of insulation layer 3, a reliable high-barrier layer is established between the charged portion of the anode plate and the grounded lithium replenishment equipment frame, fundamentally eliminating the risk of leakage and short circuits. This ensures high reliability and safety of the lithium replenishment process during long-term operation. Typically, insulation layer 3 can be made of engineering plastics or ceramics with excellent corrosion resistance and high-temperature resistance, such as polytetrafluoroethylene, polyimide, and polyetheretherketone, enabling the anode plate to withstand the erosion of the electrolyte environment and the high temperatures that may be generated during the process, thus extending the service life of the core components. The conductive layer 2 constitutes the current distribution and transmission framework of the anode plate. The conductive plate 21 serves as the main conductive path, responsible for low-loss convergence and lateral conduction of the current from the conductive cable 33, forming a stable current reference surface. Multiple conductive pillars 22, embedded in the conductive plate 21 in a matrix, form a three-dimensional conductive network framework, collecting the current from the conductive plate 21 and serving as multiple discrete and uniformly distributed vertical current output points. This uniformly transmits the current from the conductive plate 21 to the entire lithium source layer 1, fundamentally breaking the uneven current distribution caused by edge effects in traditional flat plate electrodes. This ensures that the current is uniformly applied to the working surface of the entire lithium source layer 1, ensuring that lithium ions dissolve uniformly and synchronously from all parts of the lithium source layer 1, effectively avoiding local over-compensation or under-compensation. This greatly improves the thickness and capacity consistency of the electrode lithium compensation, ultimately enhancing the performance, cycle life, and safety reliability of the finished battery. It also suppresses unstable phenomena such as local overheating and lithium dendrite growth caused by current concentration, reducing the scrap rate and providing a key guarantee for high-speed, high-efficiency continuous production. The lithium source layer 1 is the lithium-ion supply source for the electrochemical lithium replenishment reaction. Its core function is to continuously and stably provide lithium ions to the negative electrode 4 to be replenished by undergoing a controllable and uniform electrochemical oxidation reaction under the drive of an external electric field. The lithium source layer 1, together with the conductive layer 2 and the insulating layer 3, constitute an integrated plate-shaped composite electrode structure. In this structure, the function of the lithium source layer 1 directly depends on the uniform current excitation provided by the conductive layer 2.

[0019] Working principle: The entire anode plate is modularly and quickly slid into and fixed on the lithium replenishment equipment through the groove of the insulating layer 3, and the conductive cable 33 is connected to an external controllable power supply. After the negative electrode 4 passes through the guide rollers 231, the constant distance between the working surface of the negative electrode 4 and the lithium source layer 1, i.e., the electrode gap P, is precisely set by adjusting the position of the guide rollers 231. The current applied by the external power supply is input to the conductive plate 21 through the conductive cable 33. The conductive plate 21 serves as the main conductive plane, which initially diffuses the current. The current is uniformly embedded in multiple conductive plates 21 in a matrix form. The conductive pillar 22 captures and conducts the lithium source layer 1, establishing a highly uniform current density field and electric field on the entire plane of the lithium source layer 1. Under the drive of this uniform electric field, the metallic lithium in each region of the lithium source layer 1 undergoes a synchronous and uniform electrochemical oxidation reaction, stably dissolving lithium ions. Under the action of the electric field force, the dissolved lithium ions pass through the electrolyte located between the anode plate and the negative electrode plate 4, and migrate directionally to the surface of the negative electrode plate 4, which is moving at a uniform speed on the opposite side. Subsequently, the lithium ions gain electrons on the surface or inside of the negative electrode plate 4 and undergo a reduction reaction, completing the precise "lithium replenishment" of the negative electrode.

[0020] As a preferred embodiment of the present invention, the conductive layer 2 further includes at least one set of electrode spacing adjustment mechanism 23 for adjusting the distance between the negative electrode plate 4 and the anode plate. The electrode spacing adjustment mechanism 23 includes a guide roller 231, a bearing 232 and a bearing seat 233. The bearing seat 233 is fixedly disposed at the end of the conductive plate 21, and the guide roller 231 is rotatably mounted on the bearing seat 233 through the bearing 232.

[0021] The axis of the guide roller 231 is parallel to the upper surface of the conductive plate 21. Its outer cylindrical surface is configured to guide and position the negative electrode sheet 4, dynamically maintaining a constant distance between the negative electrode sheet 4 and the working surface of the lithium source layer 1 of the anode plate. By adjusting the position of the bearing seat 233 fixed at the end of the conductive plate 21, or by selecting a guide roller 231 with a specific outer diameter, the relative height between the guide roller 231 and the working surface of the lithium source layer 1 is preset, directly determining the distance between the negative electrode sheet 4 passing through it and the anode plate, i.e., the electrode spacing. During the lithium replenishment process, the negative electrode sheet 4 is on the outside... The negative electrode sheet 4 travels continuously under the traction of the tension system. When the negative electrode sheet 4 passes through the guide roller 231, the guide roller 231 rotates with the support of the bearing 232, which converts the sliding friction between the negative electrode sheet 4 and the roller surface of the guide roller 231 into rolling friction. This ensures that the negative electrode sheet 4 is always restricted to passing through the guide roller 231 at a uniform speed, and the pre-set electrode pitch remains unchanged. This eliminates the electrode pitch fluctuation caused by the vibration, sagging or thermal deformation of the negative electrode sheet 4, and fundamentally ensures the consistency of the lithium-added thickness in the length and width directions of the entire roll of negative electrode sheet 4.

[0022] As a preferred embodiment of the present invention, the pole pitch adjustment mechanism 23 is provided in two sets, which are respectively arranged at the upper and lower ends of the conductive plate 21.

[0023] In a preferred embodiment of the present invention, the conductive plate 21 and the plurality of conductive posts 22 are both made of copper.

[0024] The excellent conductivity of copper allows for low-loss current transfer to the entire lithium source layer 1 plane, achieving uniform current distribution and improving lithium replenishment quality. Furthermore, the high thermal stability of copper ensures that the conductive layer 2 does not soften or deform at high temperatures, thus maintaining the geometric accuracy of the conductive pillar matrix 22. Copper's excellent thermal conductivity facilitates the rapid lateral diffusion of Joule heat and reaction heat generated during operation, preventing the formation of localized hot spots, avoiding damage caused by thermal stress, protecting the lithium source layer 1, and extending the service life of the entire anode plate. Simultaneously, copper possesses high chemical stability, maintaining surface stability in contact with the lithium source layer 1 and in conventional electrolyte environments, and is less prone to forming a high-resistance passivation layer, ensuring long-term stability of current transmission.

[0025] As a preferred embodiment of the present invention, the guide rail 311 has an L-shaped cross-section, which matches the L-shaped slot on the lithium replenishment equipment frame.

[0026] The anode plate can be quickly positioned and installed on the lithium replenishment equipment through a simple translation and insertion action. The L-shaped structure provides a vertical load-bearing surface and a horizontal limiting surface, ensuring that the anode plate will not fall off due to its own weight in the vertical direction and will not warp or shift in the horizontal direction, thus ensuring the stability of the electrode pitch.

[0027] As a preferred embodiment of the present invention, a first sealing ring 34 is provided at the mating surface of the cable sealing seat 32 and the T-shaped seat 31, and a second sealing ring 35 is provided at the mating surface of the conductive plate 21 and the T-shaped seat 31. The first sealing ring 34 achieves a static seal between the cable channel and the external environment, preventing electrolyte vapor or liquid from seeping in along the cable and causing equipment corrosion or short circuits. The second sealing ring 35 directly prevents electrolyte from entering from the front and sides of the anode plate through the assembly gap between the conductive plate 21 and the T-shaped seat 31. When working together with the first sealing ring 34, the second sealing ring 35 helps to form a basically sealed cavity between the conductive plate 21, the T-shaped seat 31 and the cable sealing seat 32, protecting the critical electrical connection parts and insulators, and greatly improving the overall durability of the component.

[0028] In a preferred embodiment of the present invention, the lithium source layer 1 is fixedly bonded to the conductive layer 2 by compression bonding.

[0029] The lithium source layer 1 is tightly pressed onto the surface of the conductive layer 2 through a pressing composite process, forming a stable interface bond between the lithium source layer 1 and the conductive layer 2. The top of the conductive pillar 22 of the conductive layer 2 forms a tight ohmic contact with the lithium source layer 1, ensuring that the current can be efficiently transferred from each conductive pillar 22 to the lithium source layer 1. This ensures low impedance transmission of the current from the conductive pillar 22 to the lithium source layer 1, allowing lithium ions to dissolve uniformly from all points on the entire plane, further consolidating the effect of uniform lithium replenishment. The uniform thickness and density of the lithium source layer 1 are a prerequisite for ensuring consistent electrochemical behavior. The thickness and density of the lithium source layer 1 can be precisely controlled by displacement, holding time, and pressure during the rolling process.

[0030] As a preferred embodiment of the present invention, the distribution density of the matrix-distributed conductive pillars 22 in the edge region of the conductive plate 21 is greater than the distribution density of the conductive pillars 22 in the center region of the conductive plate 21.

[0031] By specifically increasing the density of conductive pillars 22 in the edge region, the equivalent resistance of the edge region is reduced. This allows the edge region to naturally carry a higher current density under the same overall voltage, thereby compensating for the current attenuation caused by the edge effect and achieving fine-tuning of the electric field distribution to counteract the edge effect. Because the current distribution path in the central region is relatively natural and uniform, a standard density of conductive pillars 22 is sufficient to meet the current output requirements. However, in the edge region, due to the existence of physical boundaries, the current naturally tends to choose the path of least resistance. Therefore, by increasing the distribution density of conductive pillars 22 in the edge region, more and denser current valves are opened, ensuring that the lithium source layer 1 dissolves at almost the same rate from the center to the edge. This ensures that the negative electrode 4 after lithium replenishment obtains a lithium layer with consistent thickness and capacity across the overall area.

[0032] As a preferred embodiment of the present invention, the distribution density of the conductive pillars 22 increases in a stepwise manner from the central region of the conductive plate 21 to its edge region.

[0033] It should be understood that the above embodiments are one or more embodiments of the present invention. There are many other embodiments and variations based on the present invention. Any variations and modifications made by those skilled in the art without making pioneering innovations are within the protection scope of the present invention.

Claims

1. A plate-shaped anode plate for lithium replenishment process of negative electrode sheet, characterized in that: An insulating layer, a conductive layer, and a lithium source layer are stacked in sequence. The insulating layer includes a T-shaped base, a cable sealing base, and a conductive cable. The top and bottom edges of the T-shaped base are provided with guide rails extending along its length. The guide rails are used to mate with corresponding slots on the frame of the lithium replenishment equipment. A cable channel is opened inside the T-shaped base. The cable channel has an entrance located on the side of the T-shaped base and an exit located on the upper surface of the T-shaped base. The cable sealing base is fixed at the entrance. The conductive cable passes through the cable sealing base and the cable channel in sequence, and extends out from the exit to be electrically connected to the conductive layer. The conductive layer includes a conductive plate and a plurality of conductive pillars. The conductive plate is fixed on the upper surface of the T-shaped base and covers the outlet of the cable channel. The plurality of conductive pillars are fixedly embedded in the interior of the conductive plate on the side away from the T-shaped base in a matrix distribution. The working surface of the top end of the conductive pillar passes through the conductive plate and forms a surface contact with the lithium source layer. The conductive pillars are electrically connected to the conductive plate and the lithium source layer respectively. The lithium source layer is fixed on the side of the conductive layer away from the insulating layer and covers the top working surface of the conductive pillar, and is used to provide lithium ions during the electrochemical lithium replenishment process.

2. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 1, characterized in that: The conductive layer further includes at least one set of electrode spacing adjustment mechanisms for adjusting the distance between the negative electrode and the anode plate. The electrode spacing adjustment mechanism includes a guide roller, a bearing, and a bearing seat. The bearing seat is fixed to the end of the conductive plate, and the guide roller is rotatably mounted on the bearing seat through the bearing.

3. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 2, characterized in that: The electrode pitch adjustment mechanism has two sets, which are respectively located at the upper and lower ends of the conductive plate.

4. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 1, characterized in that: The conductive plate and the several conductive pillars are all made of copper.

5. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 1, characterized in that: The guide rail has an L-shaped cross-section, which matches the L-shaped slot on the lithium replenishment equipment frame.

6. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 1, characterized in that: A first sealing ring is provided at the mating surface between the cable sealing seat and the T-shaped seat, and a second sealing ring is provided at the mating surface between the conductive plate and the T-shaped seat.

7. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 1, characterized in that: The lithium source layer is fixedly bonded to the conductive layer by compression bonding.

8. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 1, characterized in that: The distribution density of the matrix-distributed conductive pillars in the edge region of the conductive plate is greater than the distribution density of the conductive pillars in the center region of the conductive plate.

9. The plate-shaped anode plate for lithium replenishment process of negative electrode sheet according to claim 8, characterized in that: The distribution density of the conductive pillars increases in a stepwise manner from the center region of the conductive plate to its edge region.

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