Lithium supplementing equipment, battery production system and lithium supplementing control method

Abstract

The invention provides lithium supplement equipment, a battery production system and a lithium supplement control method, and relates to the technical field of lithium ion batteries. The lithium supplementing equipment comprises a power supply device, wherein the power supply device comprises a first electrode and a second electrode with opposite polarities; the conveying mechanism is used for conveying the pole piece, and the first electrode is electrically connected with the pole piece; the lithium supplementing unit comprises a lithium supplementing container and a lithium source, electrolyte is arranged in the lithium supplementing container, the lithium source is arranged in the lithium supplementing container and immersed in the electrolyte, and the lithium source is electrically connected with the second electrode; the power supply device, the pole piece and the lithium source form an on-off conductive loop, and an electric field is formed between the pole piece and the lithium source when the pole piece passes through the electrolyte. According to the lithium supplementing equipment, lithium supplementing is achieved during pole piece manufacturing, the initial capacity of a battery is guaranteed, the lithium supplementing equipment is compatible with a continuously-coated pole piece and an intermittently-coated pole piece by designing an on-off conductive loop, and the lithium supplementing uniformity and the lithium supplementing efficiency of the pole pieces are guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular to a lithium replenishment device, a battery production system, and a lithium replenishment control method. Background Art

[0002] Lithium-ion batteries rely on the movement of lithium ions between the positive and negative electrodes to achieve the charging and discharging process. They have advantages such as high energy density, long cycle life, and low self-discharge rate. They are used in many fields such as electronic equipment, electric vehicles, and energy storage systems.

[0003] During the first charge and discharge process of a lithium-ion battery, a solid electrolyte interface film (SEI) will form on the surface of the negative electrode. This process will consume the active lithium ions in the battery, reduce the battery's coulombic efficiency and capacity, and cause a decrease in the battery's reversible capacity. Summary of the Invention

[0004] In view of the above problems, the present application provides a lithium replenishment device, a battery production system and a lithium replenishment control method, which realizes lithium replenishment during the production of electrode sheets, reduces the consumption of lithium ions in the lithium-ion battery during the first charge and discharge process, and ensures the initial capacity of the battery. By designing a switchable conductive circuit, when replenishing lithium to the negative electrode sheet with a hollow foil area, the active layer of the continuously coated electrode sheet and the inter-coated electrode sheet can be replenished with lithium by controlling the power off of the conductive circuit, thereby ensuring the uniformity and efficiency of lithium replenishment of the electrode sheet.

[0005] In a first aspect, the present application provides a power supply device, comprising a first electrode and a second electrode with opposite polarities; a conveying mechanism, the conveying mechanism being used to convey the electrode, the first electrode and the electrode being electrically connected; a lithium replenishment unit, comprising: a lithium replenishment container and a lithium source, the lithium replenishment container being provided with an electrolyte, the lithium source being provided in the lithium replenishment container and at least partially immersed in the electrolyte, the lithium source being electrically connected to the second electrode; the power supply device, the electrode and the lithium source forming a conductive circuit that can be turned on and off, and an electric field being formed between the electrode and the lithium source when being conveyed through the electrolyte.

[0006] In one possible implementation, the pole piece includes a current collector and an active layer, the active layer is coated on at least one side of the current collector in the thickness direction, and the lithium source is arranged opposite to one side along its own thickness direction and the side of the current collector provided with the active layer to replenish lithium to the active layer.

[0007] In one possible implementation, the current collector includes a first surface and a second surface, the active layer includes a first active layer and a second active layer, the first active layer is coated on the first surface, and the second active layer is coated on the second surface; there are multiple lithium sources, and the multiple lithium sources form at least one lithium supply group, each of the lithium supply groups includes a first lithium source and a second lithium source that are oppositely and spaced apart, the conveying mechanism conveys the electrode through between the first lithium source and the second lithium source, the first lithium source is arranged on the side of the first active layer away from the second active layer to replenish lithium to the first active layer, and the second lithium source is arranged on the side of the second active layer away from the first active layer to replenish lithium to the second active layer.

[0008] In a possible implementation, there are multiple lithium supply groups, and the multiple lithium supply groups are distributed at intervals along the transmission path of the electrode piece, so as to replenish lithium for the electrode piece multiple times.

[0009] In a possible implementation, there are multiple lithium replenishing units, and the multiple lithium replenishing units are distributed in sequence along the transmission path of the electrode.

[0010] In one possible implementation, the power supply device includes multiple power supply units corresponding to the lithium source, and the power supply unit includes the first electrode and the second electrode; the second electrode of each power supply unit is electrically connected to the corresponding lithium source, and the first electrode of each power supply unit is electrically connected to the electrode.

[0011] In one possible implementation, at least part of the structure of the transmission mechanism is electrically connected to the first electrode and the electrode piece, respectively; the power supply device, the electrode piece, at least part of the structure of the transmission mechanism and the lithium source form a conductive circuit that can be switched on and off.

[0012] In a possible implementation, the conveying mechanism includes a plurality of conductive rollers corresponding one-to-one to the power supply units, and each conductive roller is electrically connected to the first electrode and the electrode piece of the corresponding power supply unit.

[0013] In one possible implementation, the plurality of conductive rollers are divided into several roller groups, each of which includes two conductive rollers opposite to each other along the thickness direction of the pole piece. When passing between the two conductive rollers, the two surfaces of the pole piece opposite to each other along the thickness direction are electrically connected to the two conductive rollers respectively.

[0014] In a possible implementation, the lithium source includes: a lithium metal layer, and the lithium metal layer is used to supply lithium.

[0015] In one possible implementation, the lithium source further includes: a conductive support layer, which is electrically connected to the power supply device and on which the lithium metal layer is disposed; and / or an insulating layer, which is located on the side of the lithium metal layer facing the electrode, and on which migration holes for lithium ions to pass are provided.

[0016] In one possible implementation, the conductive support layer includes: a conductive support rod and a conductive backplate, the conductive backplate is sleeved on the conductive support rod, the conductive support rod is used to be electrically connected to the power supply device, and the lithium metal layer is provided on the conductive backplate.

[0017] In a possible implementation, the lithium replenishment device further includes: an infiltration unit, including an infiltration container, which is arranged on the upstream side of the lithium replenishment unit along the transmission path of the electrode, and the infiltration container is provided with an electrolyte for infiltrating the electrode.

[0018] In a possible implementation, the lithium replenishment device further includes: a cleaning unit, including a cleaning container, which is arranged on the downstream side of the lithium replenishment unit along the transmission path of the electrode, and the cleaning container is provided with a cleaning liquid for cleaning the electrode after lithium replenishment.

[0019] In a possible implementation, the lithium replenishing device further includes: a drying unit, which is provided at a downstream side of the lithium replenishing unit along the conveying path of the electrode piece, and the drying unit is used to dry the electrode piece.

[0020] In a possible implementation, the electrode includes a current collector and an active layer, the current collector includes a coating area and a hollow foil area, the active layer is coated on the coating area, and the hollow foil area is not provided with the active layer;

[0021] The lithium replenishment device also includes:

[0022] An empty foil detection device is provided on the upstream side of the lithium replenishing unit along the transmission path of the electrode, and the empty foil detection device is used to detect the empty foil area;

[0023] A control unit is electrically connected to the empty foil detection device and the power supply device respectively, and the control unit controls the on / off of the power supply device according to the detection result of the empty foil detection device.

[0024] In a possible implementation, the power supply device includes multiple power supply units, there are multiple lithium sources, and the multiple power supply units are electrically connected to the multiple lithium sources respectively; the control unit independently controls the multiple power supply units according to the detection result of the empty foil detection device.

[0025] In a possible implementation, there are two empty foil detection devices, and the two empty foil detection devices respectively detect empty foil areas on two opposite surfaces of the current collector along the thickness direction thereof.

[0026] In a possible implementation, the conveying mechanism further includes: a plurality of conveying rollers, the plurality of conveying rollers being distributed along a conveying path of the pole piece, and the plurality of conveying rollers being used to convey the pole piece.

[0027] In a second aspect, the present application also provides a battery production system, including: the above-mentioned lithium replenishment equipment.

[0028] In a third aspect, the present application further provides a lithium replenishment control method, which is applied to the above-mentioned lithium replenishment device. The lithium replenishment control method comprises the following steps:

[0029] Determining a pole piece region currently reaching the lithium source, wherein the pole piece region is a region of a current collector surface corresponding to the lithium source, the current collector surface including a first surface and a second surface, and the pole piece region of at least one of the first surface and the second surface including: a coated region and a blank foil region;

[0030] The power-on state of the power supply device is controlled according to the electrode area.

[0031] In a possible implementation, controlling the power-on state of the power supply device according to the electrode area includes:

[0032] When it is determined that the empty foil area reaches the lithium source, the power supply device is controlled to be powered off;

[0033] When it is determined that the empty foil area is away from the lithium source, the power supply device is controlled to be powered on.

[0034] In a possible implementation, the power supply device includes a plurality of power supply units, there are a plurality of lithium sources, and each of the power supply units is electrically connected to the lithium source and the electrode respectively;

[0035] The method of determining that the empty foil area reaches the lithium source and then controlling the power supply device to cut off power includes: determining that the empty foil area reaches the lithium source and then controlling the power supply unit electrically connected to the lithium source to cut off power;

[0036] The step of controlling the power supply device to be powered on when the empty foil area is determined to be away from the lithium source comprises: controlling the power supply unit electrically connected to the lithium source to be powered on when the empty foil area is determined to be away from the lithium source.

[0037] In a possible implementation, when determining that the empty foil area reaches the lithium source, controlling the power supply device to cut off power includes:

[0038] Determining the lithium supply group reached by the empty foil area and the current collector surface where the empty foil area is located;

[0039] If the empty foil area is on the first surface, controlling the circuit where the first lithium source in the current lithium supply group is located to be powered off;

[0040] If the empty foil area is located on the second surface, the circuit where the second lithium source in the current lithium supply group is located is controlled to be powered off.

[0041] In a possible implementation, determining that the empty foil area reaches the lithium source includes:

[0042] determining an actual time duration for each of the empty foil areas to pass through the empty foil detection device;

[0043] Determine whether the actual duration is within a preset time range, where the preset time range includes a first time endpoint and a second time endpoint, the first time endpoint being a preset time point at which the first end of the empty foil area reaches the lithium source, and the second time endpoint being a preset time point at which the second end of the empty foil area reaches the lithium source:

[0044] If so, it is determined that the empty foil area reaches the lithium source;

[0045] If not, it is determined that the empty foil area has not reached the lithium source.

[0046] The lithium replenishment equipment of the present application realizes non-contact lithium replenishment of the electrode, reducing the consumption of lithium ions in the lithium-ion battery during the first charge and discharge process. In addition, by designing a conductive circuit that can be switched on and off, the electric field action time can be adjusted and controlled. In this way, it is compatible with continuously coated electrodes and intermittently coated electrodes, ensuring the lithium replenishment efficiency of the electrode and reducing lithium source waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0048] Figure 1 This is a schematic structural diagram of a lithium replenishment device according to an embodiment of the present application;

[0049] Figure 2 This is a schematic diagram of the structure of the pole piece of the embodiment of the present application Figure 1 ;

[0050] Figure 3 This is a schematic diagram of the structure of the pole piece of the embodiment of the present application Figure 2 ;

[0051] Figure 4 for Figure 1A schematic diagram of the structure when the middle electrode is located at the lithium supply group at the electrode inlet of the lithium replenishment container;

[0052] Figure 5 for Figure 1 A schematic diagram of the structure when the middle electrode is located at the lithium supply group at the electrode outlet of the lithium replenishment container;

[0053] Figure 6 for Figure 1 Schematic diagram of the power supply unit;

[0054] Figure 7 Schematic diagram of the lithium replenishment control method according to an embodiment of the present application.

[0055] Description of reference numerals:

[0056] 10-pole piece; 11-current collector; 11a-first surface; 11b-second surface; 11c-coating area; 11d-empty foil area; 12-active layer; 12a-first active layer; 12b-second active layer;

[0057] 100 - power supply device; 110 - first electrode; 120 - second electrode;

[0058] 200-transmission mechanism; 210-roller group; 211-conductive roller; 220-transmission roller;

[0059] 300 - lithium replenishing unit; 310 - lithium replenishing container; 320 - lithium source; 320a - first lithium source; 320b - second lithium source; 321 - conductive support layer; 3211 - conductive support rod; 3212 - conductive back plate; 322 - lithium metal layer; 323 - insulating layer;

[0060] 400-infiltration unit; 410-infiltration container;

[0061] 500-cleaning unit; 510-cleaning container;

[0062] 600-drying unit;

[0063] 700-Empty foil detection device;

[0064] 800-Control Unit. DETAILED DESCRIPTION

[0065] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0066] Lithium-ion batteries rely on the movement of lithium ions between the positive and negative electrodes to achieve the charging and discharging process. They have advantages such as high energy density, long cycle life, and low self-discharge rate. They are used in many fields such as electronic equipment, electric vehicles, and energy storage systems. During the first charge and discharge process of lithium-ion batteries, a solid electrolyte interface film (SEI) will form on the surface of the negative electrode. This process will consume the active lithium ions in the battery and reduce the battery's coulombic efficiency and capacity. For example, silicon negative electrode batteries will have 15%-30% irreversible lithium ion consumption in the first cycle, resulting in a significant decrease in the battery's reversible capacity.

[0067] Some existing negative electrode lithium replenishment equipment and processes have many shortcomings, such as incompatibility with continuous coating / intercoating electrode lithium replenishment, inability to fully wet the electrode, difficulty in uniform lithium replenishment, inability to fully clean, insufficient electrode drying, inability to customize SEI, etc., which increases the difficulty of mass production and affects the lithium replenishment effect.

[0068] In view of this, the present application provides a lithium replenishment device, a battery production system, and a lithium replenishment control method. When the electrode enters the electrolyte of the lithium replenishment container through a conveying mechanism, the power supply device establishes a potential difference between the electrode and the lithium source 320. Under the action of the electric field, the metallic lithium in the lithium source 320 undergoes an oxidation reaction to release lithium ions and enters the electrolyte. Under the action of the electric field, the lithium ions move to the surface of the electrode to be replenished with electrons to participate in the reduction reaction, forming an SEI film or embedding into the active material lattice of the electrode to form an embedded compound or reacting with the active material of the electrode to form a lithium alloy, thereby completing the lithium replenishment of the electrode. The continuous movement of the conveying mechanism causes different areas of the electrode to pass through the lithium replenishment area in turn, and the on-off control of the conductive circuit ensures that lithium ions are deposited only in the area where the active layer is located.

[0069] In this way, the lithium replenishment equipment of the present application realizes non-contact lithium replenishment of the electrode, reduces the consumption of lithium ions in the first charge and discharge process of the lithium-ion battery, and in addition, by designing a conductive circuit that can be switched on and off, the adjustment of the electric field action time is realized, so that the active layer areas of the continuously coated electrode and the inter-coated electrode can obtain uniform lithium compensation, reducing unnecessary deposition in the empty foil area. In this way, it is compatible with the continuously coated electrode and the inter-coated electrode, ensuring the lithium replenishment efficiency of the electrode and reducing the waste of lithium source 320.

[0070] Furthermore, the electric field-driven mechanism promotes the diffusion of lithium ions within the pores of the active material. Control of the conductive circuit prevents ineffective deposition of lithium metal in the empty foil area, improving raw material utilization. The conveyor mechanism also enables dynamic lithium replenishment and continuous production lines, improving replenishment efficiency and process stability.

[0071] The following specific embodiments are used to describe in detail the technical solution of the present application and how the technical solution of the present application solves the above technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0072] The following will be combined Figures 1 to 7 , describes the embodiments of the present application.

[0073] Reference Figures 1 to 6 As shown, the lithium replenishing device of this embodiment can be used to replenish lithium for the electrode 10, referring to Figure 2 and Figure 3 The electrode 10 can be a continuously coated electrode or an intermittently coated electrode. Here, the electrode can be the negative electrode of the battery. A continuously coated electrode refers to an electrode in which the active layer is continuously coated on the current collector without any empty foil area, while an intermittently coated electrode refers to an electrode in which the active layer is intermittently coated on the current collector, and there is an empty foil area between the intermittent active layers. The empty foil area can be used as the electrode ear of the electrode.

[0074] The lithium replenishment device may include a power supply device 100 , a transmission mechanism 200 and a lithium replenishment unit 300 .

[0075] The power supply device 100 includes a first electrode 110 and a second electrode 120 with opposite polarities. The transmission mechanism 200 is used to transmit the electrode piece 10. At least part of the transmission mechanism 200 is electrically connected to the first electrode 110 and the electrode piece 10 respectively.

[0076] The lithium replenishment unit 300 includes a lithium replenishment container 310 and a lithium source 320. The lithium replenishment container 310 is provided with an electrolyte. The lithium source 320 is located in the lithium replenishment container 310 and is at least partially immersed in the electrolyte. The lithium source 320 is electrically connected to the second electrode 120. The power supply device 100, the electrode 10, the transmission mechanism 200 and the lithium source 320 form a conductive circuit that can be turned on and off. When the electrode 10 is transmitted through the electrolyte, an electric field is formed between the electrode 10 and the lithium source 320 to drive the migration of lithium ions.

[0077] Optionally, the power supply device 100 may utilize a DC regulated power supply to provide a power supply system with a stable potential difference. Optionally, the current may be between 0.05C and 5C. During actual operation, the current may be adjusted based on the amount of lithium replenished or the travel speed of the electrode 10.

[0078] Optionally, the first electrode 110 is the negative electrode of the power supply device 100 , and the second electrode 120 is the positive electrode of the power supply device 100 .

[0079] When the electrode 10 enters the electrolyte of the lithium replenishment container 310 via the conveying mechanism 200, the power supply device 100 establishes a potential difference between the electrode 10 and the lithium source 320. Under the action of the electric field, the metallic lithium in the lithium source 320 releases lithium ions and enters the electrolyte. Under the action of the electric field, the lithium ions move to the surface of the electrode 10 to be replenished, forming an SEI film or embedding into the active material lattice of the electrode 10 to form an intercalation compound, or reacting with the active material of the electrode 10 to form a lithium alloy, thereby completing the lithium replenishment of the electrode 10. In this way, when the lithium-ion battery is charged and discharged for the first time after manufacturing, the consumption of lithium ions on the positive electrode side during the initial charge and discharge process can be reduced. The continuous movement of the conveying mechanism 200 causes different areas of the electrode 10 to pass through the lithium replenishment area in sequence. The on-off control of the conductive circuit ensures that lithium ions are deposited only in the area where the active layer 12 is located.

[0080] In this way, the lithium replenishment equipment of the present application realizes non-contact lithium replenishment of the electrode 10, reduces the consumption of lithium ions in the lithium-ion battery during the first charge and discharge process. In addition, by designing a conductive circuit that can be switched on and off, the adjustment of the electric field action time is realized, so that the areas where the active layers 12 of the continuously coated electrode and the inter-coated electrode are located can obtain uniform lithium compensation, reducing unnecessary deposition in the empty foil area 11d. In this way, it is compatible with the continuously coated electrode and the inter-coated electrode, ensuring the lithium replenishment efficiency of the electrode 10 and reducing the waste of lithium source 320.

[0081] Moreover, by using the lithium replenishing equipment of this embodiment, lithium can be replenished for the electrode during the electrode preparation process, and an SEI film can be formed on the surface of the active layer of the electrode in advance, thereby reducing the consumption of active lithium ions during the first charge and discharge process of the battery, which helps to improve the capacity and cycle life of the battery.

[0082] Furthermore, the electric field-driven mechanism promotes the diffusion of lithium ions within the pores of the active material. Control of the conductive loop prevents ineffective lithium metal deposition in the empty foil area 11d, improving raw material utilization. The conveyor mechanism 200 also enables dynamic lithium replenishment and a continuous production line, improving replenishment efficiency and process stability.

[0083] In some embodiments, combined Figure 1 、 Figure 2 and Figure 3 The electrode 10 includes a current collector 11 and an active layer 12. The active layer 12 is coated on at least one side of the current collector 11 in the thickness direction. The lithium source 320 is arranged opposite to the side of the current collector 11 provided with the active layer 12 along one side of its own thickness direction to replenish lithium to the active layer 12.

[0084] Optionally, the current collector 11 may be made of metal foil, such as aluminum foil, copper foil, etc., to support the active layer 12 and conduct current. Optionally, the active layer 12 may be made of silicon-based composite materials, graphite materials, etc.

[0085] Furthermore, the lithium source 320 is arranged on the side of the current collector 11 where the active layer 12 is provided to replenish lithium to the active layer 12. In this way, the arrangement position of the lithium source 320 corresponds spatially to the coating area 11c of the active layer 12. Specifically, the lithium source 320 can be fixed on the side of the active layer 12 of the transmission path of the electrode 10, so that the direction of the electric field can be perpendicular to the surface of the active layer 12.

[0086] Specifically, when the electrode 10 is transferred to the lithium replenishment unit 300, the current collector 11 is electrically connected to the transfer mechanism 200, and the lithium source 320 is electrically connected to the power supply device 100. An electric field is formed between the active layer 12, the target area requiring lithium replenishment, and the lithium source 320. Driven by the electric field, lithium ions migrate toward the surface of the active layer 12 and directly embed themselves into its internal structure.

[0087] By limiting the positional correspondence between the lithium source 320 and the active layer 12, an effective electric field is only allowed to be formed in the area covered by the active layer 12, thereby avoiding the diffusion of lithium ions into the empty foil area of ​​the current collector 11. This is compatible with the process requirements of continuous lithium replenishment of continuously coated electrodes and intermittent lithium replenishment of interleaved electrodes, so that the active layer 12 continuously coated by the continuously coated electrodes can be uniformly replenished with lithium, and the intermittent coating areas of the interleaved electrodes can also achieve accurate lithium replenishment at the corresponding positions, reducing the ineffective consumption of the lithium source 320 in the empty foil area 11d, and improving the lithium replenishment efficiency and material utilization rate.

[0088] In some embodiments, combined Figure 1 、 Figure 2 and Figure 3 The current collector 11 includes a first surface 11a and a second surface 11b, and the active layer 12 includes a first active layer 12a and a second active layer 12b. The first active layer 12a is coated on the first surface 11a, and the second active layer 12b is coated on the second surface 11b.

[0089] There can be multiple lithium sources 320, and multiple lithium sources 320 form at least one lithium supply group. Each lithium supply group includes a first lithium source 320a and a second lithium source 320b that are arranged opposite to and spaced apart from each other. The conveying mechanism 200 conveys the electrode 10 through the first lithium source 320a and the second lithium source 320b. The first lithium source 320a is arranged on the side of the first active layer 12a away from the second active layer 12b to replenish lithium to the first active layer 12a. The second lithium source 320b is arranged on the side of the second active layer 12b away from the first active layer 12a to replenish lithium to the second active layer 12b.

[0090] It can be understood that the lithium supply group is a lithium replenishment unit 300 consisting of a first lithium source 320a and a second lithium source 320b that are positioned relatively and spaced apart. Optionally, the first lithium source 320a and the second lithium source 320b can be fixed using a conductive support structure, and the spacing between the two can be adjusted according to actual usage requirements.

[0091] Optionally, in the transmission direction of the electrode 10, the length of the first lithium source 320a is equal to the length of the second lithium source 320b. In actual operation, the length of the first lithium source 320a or the second lithium source 320b can be selected according to actual needs. It is understood that the longer the length of the lithium source 320, the higher the lithium replenishment efficiency.

[0092] Optionally, the first lithium source 320 a and the second lithium source 320 b may be implemented by lithium metal plates with an insulating layer 323 on the surface and migration holes, to ensure that lithium ions in the electrolyte migrate directionally to the active layer 12 of the opposite electrode 10 .

[0093] Specifically, when the electrode 10 is driven by the conveying mechanism 200 through the gap between the lithium supply groups, the first lithium source 320a and the second lithium source 320b respectively maintain a preset distance from the first surface 11a and the second surface 11b of the electrode 10. When the conductive circuit is energized, the lithium sources 320 on both sides of the electrode 10 form independent electric fields with the corresponding active layers 12 through the electrolyte. Driven by the electric field, lithium ions migrate from the first lithium source 320a and the second lithium source 320b to the first active layer 12a and the second active layer 12b, completing double-sided lithium replenishment.

[0094] In some existing technologies, conventional lithium replenishment equipment can only replenish lithium on one side of the electrode 10 using a single lithium source 320. This requires flipping the electrode 10 or transferring it twice to achieve double-sided processing, resulting in complex processes and low efficiency. However, this solution, through the symmetrical distribution of the two lithium sources 320, allows the electrode 10 to be replenished on both sides with a single transfer, avoiding repeated operations and ensuring lithium replenishment efficiency.

[0095] Optionally, multiple lithium supply groups can be set along the conveying direction of the electrode 10 to cover different areas, thereby achieving multiple lithium replenishment of the electrode 10, avoiding insufficient lithium replenishment due to insufficient lithium replenishment time when the electrode 10 passes through a single lithium replenishment area (i.e., the area corresponding to the lithium source 320).

[0096] In some embodiments, combined Figure 1 There are multiple lithium supply groups, and the multiple lithium supply groups are distributed at intervals along the transmission path of the electrode 10, so as to replenish lithium for the electrode 10 multiple times to ensure the lithium replenishment effect.

[0097] In some embodiments, there are multiple lithium replenishing units 300 , and the multiple lithium replenishing units 300 are distributed in sequence along the transmission path of the electrode piece 10 to ensure the lithium replenishing effect and improve the quality of the electrode piece 10 .

[0098] In some embodiments, combined Figure 1 and Figure 6The power supply device 100 includes multiple power supply units corresponding to the lithium source 320. Each power supply unit includes a first electrode 110 and a second electrode 120. The second electrode 120 of each power supply unit is electrically connected to the corresponding lithium source 320, and the first electrode 110 of each power supply unit is electrically connected to the electrode 10. In this way, each power supply module can be independently controlled to be on and off, forming a current path that does not interfere with each other.

[0099] Optionally, the power supply unit may use a split-type DC power supply.

[0100] In some embodiments, combined Figure 1 and Figure 6 At least part of the structure of the transmission mechanism 200 is electrically connected to the first electrode 110 and the electrode 10 respectively; the power supply device 100, the electrode 10, at least part of the structure of the transmission mechanism 200 and the lithium source 320 form a conductive circuit that can be turned on and off.

[0101] As a result, when the electrode 10 enters the electrolyte in the lithium replenishment container 310 via the conveyor mechanism 200, the power supply device 100 establishes a potential difference between the electrode 10 and the lithium source 320. The conveyor mechanism 200 enables dynamic lithium replenishment and a continuous production line, improving lithium replenishment efficiency and process stability.

[0102] In some embodiments, combined Figure 1 and Figure 6 The transmission mechanism 200 includes a plurality of conductive rollers 211 corresponding to the power supply units, and each conductive roller 211 is electrically connected to the first electrode 110 and the electrode piece 10 of the corresponding power supply unit.

[0103] In this way, the electrode piece 10 can be clamped between the two conductive rollers 211 . The conductive rollers 211 can achieve electrical connection between the electrode piece 10 and the power supply device 100 , and can also achieve the transmission of the electrode piece 10 .

[0104] Optionally, the conductive roller 211 may be a metal roller. For example, the conductive roller 211 may be a titanium alloy roller with a silver-plated surface.

[0105] Optionally, the conductive roller 211 may be connected to a servo motor to realize its own rotation, thereby driving the pole piece 10 for transmission.

[0106] In some embodiments, combined Figure 1 and Figure 6 Multiple conductive rollers 211 are divided into several roller groups 210, each roller group 210 includes two conductive rollers 211 opposite to each other along the thickness direction of the pole piece 10. When the pole piece 10 passes between the two conductive rollers 211, the two surfaces of the pole piece opposite to each other along the thickness direction are electrically connected to the two conductive rollers respectively.

[0107] Optionally, the two conductive rollers 211 may maintain contact pressure with the pole piece 10 through an elastic pressing mechanism.

[0108] Specifically, when the electrode 10 coated with the active layer 12 on both sides enters the lithium replenishment area, the symmetrically arranged conductive rollers 211 contact and conduct with the electrode 10, and the electrode 10 passes through the gap between the first lithium source 320a and the second lithium source 320b under the transmission of the roller group 210 to achieve lithium replenishment.

[0109] The symmetrical clamping structure of the roller group 210 achieves transmission stability of the pole piece 10, reduces the uneven lithium replenishment caused by transmission jitter and the like, and ensures the quality of lithium replenishment.

[0110] In some embodiments, combined Figure 4 and Figure 5 The lithium source 320 includes a conductive support layer 321, a lithium metal layer 322 and an insulating layer 323, and the lithium metal layer 322 is used to provide lithium.

[0111] The conductive support layer 321 is electrically connected to the power supply device 100, and the lithium metal layer 322 is disposed on the conductive support layer 321. The insulating layer 323 is located on the side of the lithium metal layer 322 facing the electrode 10, and has migration holes for lithium ions to pass through.

[0112] Optionally, the conductive support layer 321 , the lithium metal layer 322 and the insulating layer 323 may be stacked in sequence along the thickness direction of the lithium source 320 .

[0113] It is understood that the conductive support layer 321 is a composite structure used to support the lithium metal layer 322 and establish a current path. The lithium metal layer 322 is a metal layer that serves as a lithium ion release source. Optionally, the lithium metal layer 322 can be made of high-purity lithium foil, lithium alloy, etc., suitable for releasing lithium ions through electrochemical reactions.

[0114] The insulating layer 323 serves as a protective structure to isolate the lithium metal layer 322 from the electrode 10. Optionally, the insulating layer 323 may be made of porous ceramics, polymer films, etc., and migration holes are provided to allow lithium ions to pass through while preventing physical contact.

[0115] Specifically, when powered, current is conducted to the conductive support layer 321, causing the lithium metal layer 322 to undergo a polarization reaction in the electrolyte. Driven by the electric field, the lithium ions released from the lithium metal layer 322 migrate directionally to the surface of the electrode 10 through the pre-designed migration holes in the insulating layer 323.

[0116] The insulating layer 323 physically blocks direct contact between the lithium metal layer 322 and the electrode 10 to avoid the risk of short circuit. Optionally, the insulating layer 323 can control the uniformity of the lithium ion migration path by designing the size and distribution density of the migration pores.

[0117] In this way, the composite conductive support structure of the conductive support layer 321 enhances the current transmission stability, improves the polarization uniformity of the lithium metal layer 322, and ensures the lithium replenishment efficiency. In addition, by designing the insulating layer 323 and the migration pore structure, a physical isolation barrier is formed while ensuring the lithium ion transmission channel, thereby improving the migration safety and controllability.

[0118] In some embodiments, combined Figure 4 and Figure 5 The conductive support layer 321 includes a conductive support rod 3211 and a conductive back plate 3212 . The conductive back plate 3212 is sleeved on the conductive support rod 3211 . The conductive support rod 3211 is used to be electrically connected to the power supply device 100 . The lithium metal layer 322 is provided on the conductive back plate 3212 .

[0119] Optionally, the conductive support rod 3211 can be made of a copper rod, a nickel-plated steel rod, etc. to establish an electrical connection with the power supply device 100. The conductive back plate 3212 can be made of a copper mesh, a porous metal plate, etc. to enhance the current distribution uniformity with the lithium metal layer 322.

[0120] The combined design of the conductive back plate 3212 and the conductive support rod 3211 ensures the stability of current transmission. It also makes the polarization degree of each region of the lithium metal layer 322 tend to be consistent by expanding the contact area with the lithium metal layer 322, thereby improving the overall lithium replenishment efficiency.

[0121] In some embodiments, combined Figure 1 The lithium replenishment device also includes an infiltration unit 400, which includes an infiltration container 410, which is arranged on the upstream side of the lithium replenishment unit 300 along the transmission path of the electrode 10, and the infiltration container 410 is provided with an electrolyte for infiltrating the electrode 10.

[0122] It is understandable that the immersion container 410 is a device for pre-treating the electrode 10 with electrolyte before lithium replenishment. Optionally, the immersion container 410 may adopt a trough structure with guide rollers.

[0123] The electrode 10 is immersed in the electrolyte via guide rollers and remains there for a predetermined period of time, allowing the active layer 12 to fully absorb the electrolyte. Thus, when the electrode 10 enters the impregnation unit 400, the electrolyte penetrates into the pores of the active layer 12 through capillary action, forming a uniform ion migration path. This ensures uniform electrolyte impregnation of the electrode 10 before lithium replenishment, eliminating the problem of lithium ion migration being hindered by insufficient impregnation during the subsequent lithium replenishment process.

[0124] In some embodiments, combined Figure 1The lithium replenishment equipment also includes a cleaning unit 500, which includes a cleaning container 510, which is arranged on the downstream side of the lithium replenishment unit 300 along the transmission path of the electrode 10. The cleaning container 510 is provided with a cleaning liquid for cleaning the electrode 10 after lithium replenishment.

[0125] As will be understood, the cleaning container 510 is used to remove residues, such as lithium salts, from the surface of the electrode 10. Optionally, the cleaning container 510 may utilize a trough structure with guide rollers. These guide rollers convey the electrode 10, which travels within the cleaning solution along a predetermined path and for a predetermined duration to remove surface residues, thereby preventing impurities from causing short circuits or corrosion in subsequent processes.

[0126] In some embodiments, combined Figure 1 The lithium replenishment equipment also includes a drying unit 600, which is arranged on the downstream side of the lithium replenishment unit 300 along the conveying path of the electrode 10. Optionally, the drying unit 600 is arranged on the downstream side of the cleaning unit 500 along the conveying path of the electrode 10. The drying unit 600 is used to dry the cleaned electrode 10.

[0127] It can be understood that the drying unit 600 is used to remove the liquid on the surface of the electrode 10. Optionally, the drying unit 600 can use a hot air circulation system, an infrared radiation heating device, etc. to achieve drying of the electrode 10 through temperature control to avoid moisture or solvent residue affecting the electrode 10 and causing short circuit or corrosion in subsequent processes.

[0128] As can be seen from the above, the electrode 10 may pass through the wetting unit 400 , the lithium replenishing unit 300 , the cleaning unit 500 and the drying unit 600 in sequence during the conveying process.

[0129] Specifically, when the electrode 10 enters the impregnation unit 400, the electrolyte penetrates into the pores of the active layer 12 by capillary action, forming a uniform ion migration channel. During the lithium replenishment process, the pre-impregnated electrolyte prompts lithium ions to migrate directionally to the active layer 12 under the action of the electric field, avoiding uneven lithium replenishment caused by insufficient local electrolyte. After the lithium replenishment is completed, the electrode 10 enters the cleaning unit 500, and the cleaning liquid can dissolve the residual electrolyte, reaction by-products, etc. on the electrode 10. The cleaned electrode 10 enters the drying unit 600, and the surface liquid is removed by hot air, radiation, etc., thereby completing the lithium replenishment process of the electrode 10.

[0130] In some existing technologies, existing lithium replenishment devices often omit the wetting, cleaning, and drying steps, leading to problems such as uneven electrolyte distribution on the surface of the electrode 10, residue accumulation after lithium replenishment, and excessive moisture content in the electrode 10. This solution forms a complete process flow by setting up sequentially connected pre-treatment and post-treatment units. This establishes a uniform electrolyte distribution before lithium replenishment, removes reaction byproducts after lithium replenishment, and ensures the dryness of the electrode 10. This overcomes the shortcomings of traditional processes that cannot ensure the quality stability of lithium replenishment of electrode plates through continuous coating or intermittent coating.

[0131] It can be seen that the synergistic effect of the entire process enables both continuous coating and intermittent coating electrodes to obtain consistent lithium replenishment effects, meeting the requirements of high energy density batteries for electrode 10 interface stability.

[0132] In some embodiments, combined Figure 2 and Figure 3 The pole piece 10 includes a current collector 11 and an active layer 12. The current collector 11 includes a coating area 11c and a hollow foil area 11d. The active layer 12 is coated on the coating area 11c, and the hollow foil area 11d is not provided with the active layer 12.

[0133] The lithium replenishment equipment includes an empty foil detection device 700 and a control unit 800. The empty foil detection device 700 is arranged on the upstream side of the lithium replenishment unit 300 along the transmission path of the electrode 10, and is used to detect the empty foil area 11d of the electrode 10. The control unit 800 is electrically connected to the empty foil detection device 700 and the power supply device 100 respectively, and controls the power supply device 100 to be turned on and off according to the detection results.

[0134] Optionally, the empty foil detection device 700 may be a sensor. For example, a photoelectric sensor, a color sensor, a camera, or the like may be used. The empty foil detection device 700 determines the boundary position of the empty foil area 11d through image acquisition and processing, thereby sending a detection signal to the control unit 800. The control unit 800 is configured to receive the signal from the empty foil detection device 700 and output a power on / off command.

[0135] Specifically, as the electrode 10 travels along the conveyor path, the empty foil detection device 700 continuously scans the surface of the electrode 10 upstream of the lithium replenishment unit 300 to identify the starting and ending positions of the empty foil area 11d. The detection signal from the empty foil detection device 700 is transmitted in real time to the control unit 800. Based on the arrival time and location information of the empty foil area 11d, the control unit 800 sends a power-off command to the power supply device 100. When the empty foil area 11d reaches the lithium source 320, the conductive circuit of the lithium source 320 opposite to the empty foil area 11d is disconnected, preventing the lithium source 320 from continuously releasing lithium ions in the empty foil area 11d. When the empty foil area 11d is detected to have left the lithium source 320, the control unit 800 sends a power-on command to the power supply device 100, restoring the electric field to achieve lithium replenishment. Thus, intermittent lithium replenishment is achieved.

[0136] In this way, through the coordinated operation of the empty foil detection device 700 and the control unit 800, the lithium replenishment operation is performed only in the area where the active layer is located, eliminating the invalid electric energy and lithium source 320 consumption when the empty foil area 11d passes through, while maintaining the uniformity of the electric field distribution and ensuring the quality of lithium replenishment.

[0137] Optionally, the lithium replenishment device further includes a speed detector, which is communicatively connected to the control unit 800 and is suitable for detecting the actual transmission speed of the electrode 10 and feeding back the speed to the control unit 800.

[0138] In some embodiments, combined Figure 1 The power supply device includes multiple power supply units, there are multiple lithium sources 320, and the multiple power supply units are electrically connected to the multiple lithium sources 320 respectively; the control unit 800 independently controls the multiple power supply units according to the detection results of the empty foil detection device 700.

[0139] In this way, the design ensures that the current paths between each power supply unit do not interfere with each other, and the control unit 800 can control the connection and disconnection between each power supply unit and the lithium source 320 according to the detection result of the empty foil detection device 700.

[0140] In some embodiments, combined Figure 1 There are two empty foil detection devices 700, and the two empty foil detection devices 700 respectively detect the empty foil areas 11d on two opposite surfaces of the current collector 11 along its thickness direction.

[0141] It can be understood that in some situations, the active layer 12 coated on the first surface 11a and the second surface 11b of the current collector 11 is asymmetric, and the two empty foil detection devices 700 respectively detect the empty foil areas 11d on the two surfaces of the current collector 11 to ensure the lithium replenishment effect on the two active layers 12 respectively.

[0142] In some embodiments, combined Figure 1 The conveying mechanism 200 further includes a plurality of conveying rollers 220, which are distributed along the conveying path of the electrode 10. The plurality of conveying rollers 220 are used to convey the electrode 10, that is, the electrode 10 can pass through the plurality of conveying rollers 220 in sequence. In this way, the conveying rollers 220 can work together with the conductive roller 211 to convey the electrode 10, ensuring the stability of the conveying of the electrode 10.

[0143] Optionally, the conveying roller 220 may be connected to a servo motor to realize its own rotation, thereby driving the pole piece 10 to be transmitted.

[0144] In addition, an embodiment of the present application also provides a battery production system, including the lithium replenishment equipment in any of the above embodiments.

[0145] By designing the lithium replenishment equipment, the battery production system realizes non-contact lithium replenishment of the electrode 10, reducing the consumption of lithium ions in the lithium-ion battery during the initial charge and discharge process. In addition, by designing a switchable conductive circuit, the area where the active layer 12 of the continuously coated electrode and the intermediately coated electrode is located can obtain uniform lithium compensation, thereby ensuring the lithium replenishment efficiency of the electrode 10, reducing the waste of lithium source 320, and ensuring the production efficiency of the electrode 10 during the battery production process.

[0146] Reference Figures 1 to 6 ,as well as Figure 7 The present application also provides a lithium replenishment control method, which is applied to the lithium replenishment device in any of the above embodiments. The lithium replenishment control method includes the following steps:

[0147] S1, determine the electrode area currently reaching the lithium source 320, the electrode area is the area of ​​the collector surface corresponding to the lithium source 320, the collector surface includes a first surface 11a and a second surface 11b, and the electrode area of ​​at least one of the first surface 11a and the second surface 11b includes: a coating area 11c and an empty foil area 11d.

[0148] It can be understood that when the lithium replenishing equipment replenishes lithium to the electrode, since lithium sources 320 are respectively provided on both sides of the electrode 10 along the thickness direction, if the empty foil area 11d is provided on only one surface of the electrode 10 and the empty foil area 11d is not provided on the other surface, then the lithium source 320 opposite to the surface of the electrode 10 without the empty foil area 11d can always be in an on state or can be controlled to be on or off as needed; if the empty foil area 11d is not provided on both sides of the electrode 10, then the two lithium sources 320 can always be in an on state or can be controlled to be on or off as needed.

[0149] S2, controlling the power-on state of the power supply device 100 according to the electrode area.

[0150] Specifically, as the electrode sheet 10 travels along the conveyor path, the empty foil detection device 700 continuously scans the surface of the electrode sheet 10 upstream of the lithium replenishment unit 300 to identify the starting and ending positions of the empty foil area 11d. The detection signal from the empty foil detection device 700 is transmitted in real time to the control unit 800. Based on the arrival time and location information of the empty foil area 11d, the control unit 800 sends a power-off command to the power supply device 100. When the empty foil area 11d enters the electric field range of the lithium replenishment unit 300, the conductive circuit containing the lithium source 320 opposite the empty foil area 11d is disconnected, preventing the lithium source 320 from continuously releasing lithium ions in the empty foil area 11d. When the empty foil area 11d is detected to have left the lithium replenishment unit 300, i.e., when the coated area 11c reaches the lithium replenishment unit 300, the control unit 800 sends a power-on command to the power supply device 100, restoring the electric field to achieve lithium replenishment. The control logic matches the electrode area characteristics with the power supply status in real time, so that the electrode 10 maintains the electrolysis reaction only in the effective lithium replenishment area.

[0151] It can be understood that controlling the power-on state of the power supply device 100 in this application refers to controlling the power-on state of the conductive circuit where the lithium source 320 reached by the empty foil area 11d is located. When there are multiple lithium sources 320, the power-on state of the conductive circuit where each lithium source 320 is located can be independently controlled.

[0152] Exemplarily, the transmission speed of the electrode 10 and the distance to the lithium source 320 are both preset values. The control unit 800 calculates the preset time for the empty foil area 11d to reach the lithium source 320 and performs a power-off operation at the preset time.

[0153] By combining regional identification with power supply control, precise lithium replenishment control is achieved for continuously or intermittently coated electrodes, eliminating the energy waste caused by the lack of regional identification in traditional processes and ensuring the stability of the lithium replenishment process for the active layer 12. This control method can adapt to the transport of electrodes 10 with different coating intervals and improves the compatibility and reliability of the lithium replenishment process.

[0154] In some embodiments, the power-on state of the power supply device 100 is controlled according to the electrode area, including: determining that the empty foil area 11d reaches the lithium source 320, then controlling the power supply device 100 to cut off the power; determining that the empty foil area 11d leaves the lithium source 320, then controlling the power supply device 100 to turn on the power.

[0155] It can be understood that the empty foil detection device 700 can be used to detect the position of the intersection of the empty foil area 11d and the coated area 11c, that is, the initial position of the empty foil area 11d (the end position of the coated area 11c) and the end position of the empty foil area 11d (the initial position of the coated area 11c).

[0156] Specifically, the control unit 800 calculates the time when the empty foil area 11d reaches the lithium source 320 through the signal of the empty foil detection device 700. When the empty foil area 11d reaches the lithium source 320, the control unit 800 sends a power-off command to the power supply device 100 to prevent the lithium source 320 from continuously releasing lithium ions in the empty foil area 11d; the control unit 800 calculates the time when the empty foil area 11d leaves the lithium source 320 through the signal of the empty foil detection device 700. When the empty foil area 11d leaves the lithium source 320, that is, when the coated area 11c reaches the lithium source 320, the control unit 800 sends a power-on command to the power supply device 100 to restore the electric field effect to achieve lithium replenishment.

[0157] In this way, through the control method of regional identification and power supply linkage, precise lithium replenishment control of continuously coated electrodes or intermittently coated electrodes is achieved, the ineffective lithium replenishment of the empty foil area 11d is reduced, and the normal lithium replenishment electric field of the coating area 11c is maintained, thereby improving the effective utilization rate of active lithium.

[0158] In some embodiments, the power supply device 100 includes multiple power supply units, there are multiple lithium sources 320, and each power supply unit is electrically connected to the lithium source 320 and the electrode 10 respectively; when it is determined that the empty foil area 11d reaches the lithium source 320, the power supply device 100 is controlled to cut off power, including: determining that the empty foil area 11d reaches the lithium source 320, and controlling the power supply unit electrically connected to the lithium source 320 to cut off power.

[0159] In this way, when the empty foil area 11d reaches the lithium source 320, the control unit 800 sends a power-off command to the power supply unit corresponding to the power supply device 100 to prevent the lithium source 320 from continuously releasing lithium ions in the empty foil area 11d; when the empty foil area 11d leaves the lithium source 320, that is, when the coated area 11c reaches the lithium source 320, the control unit 800 sends a power-on command to the power supply unit corresponding to the power supply device 100 to restore the electric field effect to achieve lithium replenishment, thereby realizing precise lithium replenishment control of continuously coated electrodes or intermittently coated electrodes and ensuring lithium replenishment efficiency.

[0160] In some embodiments, when it is determined that the empty foil area 11d reaches the lithium source 320, the power supply device 100 is controlled to be powered off, including: determining the lithium supply group where the empty foil area 11d is located and the current collector surface where the empty foil area 11d is located; the surface of the current collector 11 includes a first surface 11a and a second surface 11b; if the empty foil area 11d is on the first surface 11a, the circuit where the first lithium source 320a is located is controlled to be powered off; if the empty foil area 11d is on the second surface 11b, the circuit where the second lithium source 320b is located is controlled to be powered off.

[0161] Optionally, if it is determined that the empty foil area 11d leaves the lithium source 320, controlling the power supply device 100 to be powered on includes: determining that the empty foil area 11d leaves the lithium source 320, and controlling the power supply unit electrically connected to the lithium source 320 to be powered on, so that the active material adjacent to the empty foil area can be replenished with lithium in time.

[0162] Optionally, two empty foil detection devices 700 are provided, namely a first detection device and a second detection device, and the first detection device and the second detection device correspond to detecting the first surface 11 a and the second surface 11 b respectively.

[0163] Specifically, the control unit 800 calculates the time when the empty foil area 11d on the first surface 11a and the second surface 11b reaches the lithium source 320 based on the signals of the first detection device and the second detection device respectively. When the empty foil area 11d of the first surface 11a reaches the lithium source 320, the control unit 800 sends a power-off instruction for the circuit where the first lithium source 320a is located to the power supply device 100. When the empty foil area 11d of the second surface 11b reaches the lithium source 320, the control unit 800 sends a power-off instruction for the circuit where the second lithium source 320b is located to the power supply device 100.

[0164] The surface-independent control mechanism can adapt to the differentiated lithium replenishment requirements of the double-sided heterogeneously coated electrode 10, prevent the power failure of one side from affecting the normal lithium replenishment process of the other side, and ensure the overall lithium replenishment uniformity of the electrode 10.

[0165] In some embodiments, determining that the empty foil area 11d reaches the lithium source 320 includes: determining the actual duration of each empty foil area 11d passing through the empty foil detection device 700, and determining whether the actual duration is within a preset time range, the preset time range including a first time endpoint and a second time endpoint, the first time endpoint being a preset time point at which the first end of the empty foil area 11d reaches the lithium source 320, and the second time endpoint being a preset time point at which the second end of the empty foil area 11d reaches the lithium source 320. If so, it is determined that the empty foil area 11d reaches the lithium source 320; if not, it is determined that the empty foil area 11d does not reach the lithium source 320, that is, the coated area 11c reaches the lithium source 320.

[0166] It is understood that the settings in this embodiment are applicable to either of the two empty foil detection devices 700. The actual duration refers to the time it takes for the empty foil area 11d to enter the detection area and completely exit it, that is, the time elapsed between the initial position of the empty foil area 11d and the final position of the empty foil area 11d. The first endpoint is the time reference point when the leading edge of the empty foil area 11d reaches the corresponding position of the lithium source 320. This endpoint serves as the starting condition for triggering the power-off command. The second endpoint is the time reference point when the end of the empty foil area 11d completely passes the corresponding position of the lithium source 320. This endpoint serves as the condition for terminating the execution of the power-off command.

[0167] Specifically, during the transmission of the electrode 10, when the empty foil area 11d is detected entering the detection area, the control unit 800 calculates the actual passage time of the empty foil area 11d based on the transmission speed of the electrode 10. When the actual passage time is compared with a preset time range, if the actual passage time falls within the interval, it is determined that the empty foil area 11d has completely covered the lithium source 320, and the control unit 800 cuts off the corresponding power supply circuit. If the actual passage time exceeds the interval, it is determined that the coated area 11c has passed normally, and the electric field conduction state is maintained.

[0168] This design accurately identifies the transition boundary between the bare foil area 11d and the coated area 11c of the electrode 10, preventing false or missed triggering of the electric field due to detection errors. During the lithium replenishment process of discontinuously coating the electrode 10, the timing of power outages can be precisely controlled, ensuring stable conduction of the lithium replenishment electric field in the coated area 11c and guaranteeing the reliability and safety of the lithium replenishment process.

[0169] Optional, combined Figure 1 There may be multiple lithium supply groups, that is, multiple lithium sources 320 may be provided on the transmission path of the electrode 10. For example, there may be two lithium supply groups, which are respectively provided at the inlet and outlet of the electrode 10 near the lithium replenishment container 310.

[0170] It is understandable that in the lithium replenishment control method of the present application, the control unit 800 can control the on / off of the conductive circuits connected to the first lithium source 320a and the second lithium source 320b in the multiple lithium supply groups according to the detection results of the empty foil detection device 700.

[0171] Correspondingly, three, four, six, etc. lithium supply groups can be provided on the transmission path of the electrode 10. The specific number can be selectively designed according to the length of the transmission path of the actual electrode 10, and is not limited here.

[0172] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0173] It should be noted that phrases such as "one embodiment," "an embodiment," "exemplary embodiments," and "some embodiments" in this specification may indicate embodiments that may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not.

[0174] Generally speaking, terms should be understood, at least in part, based on the context in which they are used. For example, as used herein, the term "one or more" can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense, depending at least in part on the context. Similarly, terms such as "a," "an," or "the" can also be understood to convey either singular or plural usage, depending at least in part on the context.

[0175] It should be readily understood that “on,” “above,” and “over” in this disclosure should be interpreted in the broadest manner, such that “on” means not only “directly on something,” but also includes “on something” with intervening features or layers therebetween, and “above” or “over” includes not only the meaning of “above” or “over,” but also includes “above” or “over” with no intervening features or layers therebetween (i.e., directly on something).

[0176] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features with equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A lithium replenishing device for replenishing lithium for electrode, characterized in that: include: a power supply device, the power supply device comprising a first electrode and a second electrode having opposite polarities; A conveying mechanism, the conveying mechanism is used to convey the electrode piece, the first electrode and the electrode piece are electrically connected; A lithium replenishment unit, comprising: a lithium replenishment container and a lithium source, wherein the lithium replenishment container is provided with an electrolyte, the lithium source is provided in the lithium replenishment container and is at least partially immersed in the electrolyte, and the lithium source is electrically connected to the second electrode; The power supply device, the pole piece and the lithium source form a conductive circuit that can be switched on and off. When the pole piece passes through the electrolyte, an electric field is formed between the pole piece and the lithium source.

2. The lithium replenishing device according to claim 1, characterized in that: The pole piece includes a current collector and an active layer, wherein the active layer is coated on at least one side surface of the current collector in the thickness direction. One side of the lithium source along its thickness direction is arranged opposite to the side of the current collector where the active layer is provided, so as to replenish lithium to the active layer.

3. The lithium replenishing device according to claim 2, characterized in that: The current collector includes a first surface and a second surface, the active layer includes a first active layer and a second active layer, the first active layer is coated on the first surface, and the second active layer is coated on the second surface; There are multiple lithium sources, and the multiple lithium sources form at least one lithium supply group. Each lithium supply group includes a first lithium source and a second lithium source that are arranged opposite to and spaced apart from each other. The conveying mechanism conveys the electrode through between the first lithium source and the second lithium source. The first lithium source is arranged on a side of the first active layer away from the second active layer to replenish lithium to the first active layer. The second lithium source is arranged on a side of the second active layer away from the first active layer to replenish lithium to the second active layer.

4. The lithium replenishing device according to claim 3, characterized in that: There are multiple lithium supply groups, and the multiple lithium supply groups are distributed at intervals along the transmission path of the electrode, so as to replenish lithium for the electrode multiple times.

5. The lithium replenishing device according to claim 1, characterized in that: There are a plurality of lithium replenishing units, and the plurality of lithium replenishing units are distributed in sequence along the transmission path of the electrode.

6. The lithium replenishing device according to claim 1, characterized in that: The power supply device includes a plurality of power supply units corresponding to the lithium sources, and the power supply units include the first electrode and the second electrode; The second electrode of each power supply unit is electrically connected to the corresponding lithium source, and the first electrode of each power supply unit is electrically connected to the electrode sheet.

7. The lithium replenishing device according to claim 6, characterized in that: At least a portion of the transmission mechanism is electrically connected to the first electrode and the electrode piece respectively; The power supply device, the pole piece, at least a part of the structure of the transmission mechanism and the lithium source form a conductive circuit that can be switched on and off.

8. The lithium replenishing device according to claim 7, characterized in that: The transmission mechanism includes a plurality of conductive rollers, and the conductive rollers are in one-to-one correspondence with the power supply units. Each of the conductive rollers is electrically connected to the first electrode and the electrode piece of the corresponding power supply unit.

9. The lithium replenishing device according to claim 8, characterized in that: The multiple conductive rollers are divided into several roller groups, each roller group includes two conductive rollers opposite to each other along the thickness direction of the pole piece. When the pole piece passes between the two conductive rollers, the two surfaces of the pole piece opposite to each other along the thickness direction are electrically connected to the two conductive rollers respectively.

10. The lithium replenishing device according to any one of claims 1 to 9, characterized in that: The lithium source includes a lithium metal layer, and the lithium metal layer is used for supplying lithium.

11. The lithium replenishing device according to claim 10, characterized in that: The lithium source also includes: a conductive support layer, the conductive support layer being electrically connected to the power supply device, the lithium metal layer being disposed on the conductive support layer; and / or, An insulating layer is located on a side of the lithium metal layer facing the pole piece, and the insulating layer is provided with migration holes for lithium ions to pass through.

12. The lithium replenishing device according to claim 11, characterized in that: The conductive support layer includes: a conductive support rod and a conductive back plate. The conductive back plate is sleeved on the conductive support rod. The conductive support rod is used to be electrically connected to the power supply device. The lithium metal layer is arranged on the conductive back plate.

13. The lithium replenishing device according to any one of claims 1 to 9, characterized in that: Also includes: The infiltration unit includes an infiltration container, which is arranged at the upstream side of the lithium replenishing unit along the transmission path of the electrode piece. The infiltration container is provided with an electrolyte for infiltrating the electrode piece.

14. The lithium replenishing device according to any one of claims 1 to 9, characterized in that: Also includes: The cleaning unit includes a cleaning container, which is arranged at the downstream side of the lithium replenishing unit along the transmission path of the electrode piece. The cleaning container is provided with a cleaning liquid for cleaning the electrode piece after lithium replenishment.

15. The lithium replenishing device according to any one of claims 1 to 9, characterized in that: Also includes: The drying unit is provided at the downstream side of the lithium replenishing unit along the transmission path of the electrode, and is used for drying the electrode.

16. The lithium replenishing device according to any one of claims 1 to 9, characterized in that: The pole piece includes a current collector and an active layer, the current collector includes a coating area and a hollow foil area, the active layer is coated on the coating area, and the hollow foil area is not provided with the active layer; The lithium replenishment device also includes: An empty foil detection device is provided on the upstream side of the lithium replenishing unit along the transmission path of the electrode, and the empty foil detection device is used to detect the empty foil area; A control unit is electrically connected to the empty foil detection device and the power supply device respectively, and the control unit controls the on / off of the power supply device according to the detection result of the empty foil detection device.

17. The lithium replenishing device according to claim 16, characterized in that: The power supply device includes multiple power supply units, there are multiple lithium sources, and the multiple power supply units are electrically connected to the multiple lithium sources respectively; the control unit independently controls the multiple power supply units according to the detection result of the empty foil detection device.

18. The lithium replenishing device according to claim 16, characterized in that: There are two empty foil detection devices, and the two empty foil detection devices respectively detect empty foil areas on two opposite surfaces of the current collector along the thickness direction thereof.

19. The lithium replenishing device according to any one of claims 1 to 9, characterized in that: The conveying mechanism further includes: a plurality of conveying rollers, the plurality of conveying rollers being distributed along the conveying path of the pole piece, and the plurality of conveying rollers being used to convey the pole piece.

20. A battery production system, characterized in that: include: The lithium replenishing device according to any one of claims 1 to 19.

21. A lithium replenishment control method, applied to the lithium replenishment device according to any one of claims 1 to 19, characterized in that: The following steps are involved: Determining a pole piece region currently reaching the lithium source, wherein the pole piece region is a region of a current collector surface corresponding to the lithium source, the current collector surface including a first surface and a second surface, and the pole piece region of at least one of the first surface and the second surface including: a coated region and a blank foil region; The power-on state of the power supply device is controlled according to the electrode area.

22. The lithium replenishment control method according to claim 21, characterized in that: Controlling the power-on state of the power supply device according to the electrode area includes: When it is determined that the empty foil area reaches the lithium source, the power supply device is controlled to be powered off; When it is determined that the empty foil area is away from the lithium source, the power supply device is controlled to be powered on.

23. The lithium replenishment control method according to claim 22, characterized in that: The power supply device includes a plurality of power supply units, there are a plurality of lithium sources, and each of the power supply units is electrically connected to the lithium source and the electrode respectively; The method of determining that the empty foil area reaches the lithium source and then controlling the power supply device to cut off power includes: determining that the empty foil area reaches the lithium source and then controlling the power supply unit electrically connected to the lithium source to cut off power; The step of controlling the power supply device to be powered on when the empty foil area is determined to be away from the lithium source comprises: controlling the power supply unit electrically connected to the lithium source to be powered on when the empty foil area is determined to be away from the lithium source.

24. The lithium replenishment control method according to claim 22, characterized in that: The method of determining that the empty foil area reaches the lithium source and then controlling the power supply device to cut off power comprises: Determining the lithium supply group reached by the empty foil area and the current collector surface where the empty foil area is located; If the empty foil area is on the first surface, controlling the circuit where the first lithium source in the current lithium supply group is located to be powered off; If the empty foil area is located on the second surface, the circuit where the second lithium source in the current lithium supply group is located is controlled to be powered off.

25. The lithium replenishment control method according to claim 22, characterized in that: Determining that the empty foil area reaches the lithium source includes: determining an actual time duration for each of the empty foil areas to pass through the empty foil detection device; Determine whether the actual duration is within a preset time range, where the preset time range includes a first time endpoint and a second time endpoint, the first time endpoint being a preset time point at which the first end of the empty foil area reaches the lithium source, and the second time endpoint being a preset time point at which the second end of the empty foil area reaches the lithium source: If so, it is determined that the empty foil area reaches the lithium source; If not, it is determined that the empty foil area has not reached the lithium source.

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