A lithium battery formation device

Abstract

This invention belongs to the field of battery manufacturing technology and discloses a lithium battery formation equipment, including a formation cabinet. The formation cabinet is equipped with a battery carrier, a battery carrier base, and clamps. The clamps are used for battery support and positioning. The clamps are linearly arranged on the base and can switch between a single-layer horizontal arrangement mode and a multi-layer vertical stacking mode on the base. This invention solves the problem of reverse connection of pouch batteries due to the similar appearance of the positive and negative tabs by designing the clamps to switch between "single-layer horizontal arrangement mode" and "multi-layer vertical stacking mode". During the calibration stage, the clamps switch to the multi-layer vertical stacking mode, ensuring that the tabs on the same side are strictly collinear and closely arranged in the vertical direction. This arrangement is not for automatic identification but rather to provide optimal observation conditions for manual visual inspection or upstream vision systems.

Description

Technical Field

[0001] This invention belongs to the field of battery production technology, specifically relating to a lithium battery formation device. Background Technology

[0002] Formation refers to the initial charge-discharge cycle of a newly assembled battery using a small current, which causes the electrolyte to decompose and reduce on the negative electrode surface, forming a stable solid electrolyte interphase (SEI) film. Among various battery types, pouch lithium batteries are widely used in consumer electronics, electric vehicles, and energy storage systems due to their high energy density, lightweight design, and excellent safety performance.

[0003] However, the positive and negative tabs of pouch batteries are highly similar in appearance, both being metal foil leads with only slight color differences. Furthermore, some models use a same-side tab design, making them highly susceptible to polarity misjudgment due to manual loading or automated positioning errors. If the positive and negative electrodes are reversed with the formation power supply, the applied voltage will force abnormal electrochemical reactions within the battery: the negative electrode potential will be abnormally raised to above 3V, causing the copper current collector to oxidize and dissolve into Cu²⁺ ions; the positive electrode will be excessively reduced, triggering transition metal dissolution, lattice collapse, and even oxygen release. These irreversible side reactions not only severely damage the electrode structure but also generate large amounts of gas, causing the battery to swell rapidly. In extreme cases, localized high temperatures and uncontrolled reactions of active materials may trigger a chain thermal runaway, leading to smoke, fire, or even explosion. In addition, reverse connection can damage the constant current and constant voltage channels of the formation equipment, causing short circuits, blown fuses, or control board malfunctions, affecting the overall production line efficiency, product yield, and personnel safety. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a lithium battery formation device to solve the problems existing in the background art.

[0005] To address the aforementioned technical problems, the present invention provides a lithium battery formation device, comprising a formation cabinet, which is equipped with a battery carrier, a battery carrier base, and clamps. The clamps are used for supporting and positioning the batteries. The clamps are arranged linearly on the base, and can switch between a single-layer horizontal arrangement mode and a multi-layer vertical stacking mode on the base. Before formation, the clamps are switched to the multi-layer vertical stacking mode to calibrate the positive or negative electrode of the battery, avoiding the need for reverse installation of the battery during formation. After calibration, the clamps are switched from the multi-layer vertical stacking mode to the single-layer horizontal arrangement mode to achieve good electrical connection, uniform restraint pressure, efficient thermal management, and gas discharge during the formation process.

[0006] Preferably, the base is provided with a rotating arm, and the clamp is mounted on the rotating arm. The rotating arm drives the clamp to change its posture in space. The clamp always remains horizontal on the rotating arm, so that the battery on the clamp is always in a flat position during mode switching. When the clamp is in a multi-layer vertical stacking mode, multiple batteries on the same rotating arm are arranged in layers along the vertical direction, and the electrodes on the same side of all batteries are located on the same vertical line, which facilitates polarity consistency verification by visual recognition system or manual method. When switching to a single-layer horizontal arrangement mode, all batteries are located in the same horizontal plane to ensure stable probe contact, uniform distribution of restraint pressure, efficient heat conduction path, and timely discharge of gas generated by electrolyte decomposition during formation.

[0007] Furthermore, a control gear is fixedly mounted on the base, and the axis of the control gear is coaxial with the rotation axis of the rotating arm; multiple synchronous gears are linearly arranged along the length of the rotating arm, and the synchronous gears are rotatably mounted on the rotating arm; the control gear and each synchronous gear are respectively connected to the corresponding clamp; the control gear and the synchronous gears are connected by a synchronous transmission belt; when the rotating arm rotates around its own rotation axis, the control gear remains stationary, and the synchronous transmission belt drives each synchronous gear to rotate in the opposite direction relative to the rotating arm, so that each clamp always maintains a horizontal posture during the overall movement of the rotating arm.

[0008] Furthermore, the control gear and the synchronizing gear have the same specifications; the synchronizing transmission belt is a toothed synchronizing belt or a transmission chain, and the toothed synchronizing belt has teeth on the inner side.

[0009] Furthermore, a tensioning pulley is provided on the transmission path of the synchronous transmission belt. The tensioning pulley is rotatably mounted on the rotating arm and abuts against the non-working side of the synchronous transmission belt to apply tension to the synchronous transmission belt, ensuring that each synchronous gear and the synchronous transmission belt maintain meshing transmission.

[0010] Furthermore, the rotating arm is provided with a guide rail along its own length direction, and the clamp is fixedly connected to the slider. The slider and the guide rail are adapted to each other. The rotating arm is also provided with a spacing synchronization adjustment component. The spacing synchronization adjustment component is drivenly connected to the slider. The spacing synchronization adjustment component can synchronously drive all sliders to move along the guide rail to adjust the spacing between adjacent clamps. When the clamps are in a multi-layer vertical stacking mode, the spacing between adjacent clamps is reduced by the spacing synchronization adjustment component, so that the electrodes on the same side of each battery are closely aligned in the vertical direction, which facilitates polarity consistency verification by visual recognition system or manual method.

[0011] Furthermore, a transmission limiting structure is provided between the clamp and the synchronous gear. The transmission limiting structure includes a limiting member on the slider and a limiting groove on the rotating arm, or vice versa. Through the transmission limiting structure, when the rotating arm rotates around its axis, the relative rotation of the clamp with respect to the synchronous gear is restricted, thereby ensuring that the clamp rotates synchronously in the opposite direction with the synchronous gear and maintaining the horizontal posture of the clamp. When the clamp is in a multi-layer vertical stacking mode, the limiting groove is on the same vertical line and the vertical line is parallel to the length direction of the rotating arm, so as to allow the spacing synchronous adjustment component to adjust the clamp spacing without interfering with the limiting function.

[0012] Furthermore, the base is provided with a pair of rotating arms, which are symmetrically arranged in the same vertical plane along the vertical direction; when all the clamps are in a single-layer horizontal arrangement mode, the length directions of the two rotating arms are collinear and on the same horizontal line; this reduces the overall vertical height occupied by the battery carrier when it switches to a multi-layer vertical stacking mode.

[0013] Furthermore, the spacing synchronization adjustment component is a parallelogram linkage mechanism, each linkage mechanism is formed by two links of equal length hinged together, and connects two adjacent sliders.

[0014] The main technical effects of this invention are reflected in the following aspects: This invention solves the problem of reverse connection in pouch batteries due to the similar appearance of the positive and negative tabs by designing a fixture that can switch between a "single-layer horizontal arrangement mode" and a "multi-layer vertical stacking mode." During the calibration stage, the fixture switches to the multi-layer vertical stacking mode, ensuring that the tabs on the same side are strictly collinear and closely arranged in the vertical direction. This arrangement is not for automatic identification, but rather to provide optimal observation conditions for manual visual inspection or upstream vision systems. Since current battery manufacturing commonly uses color (e.g., red / blue) or shape (e.g., round hole / square hole) to distinguish the tabs, this highly aligned physical layout greatly reduces the probability of misjudgment and avoids serious consequences such as copper current collector dissolution, gas bulging, or even thermal runaway caused by reverse connection. Therefore, although this structure does not contain an identification algorithm, it mechanically constructs a highly fault-tolerant precondition for polarity verification, significantly improving safety redundancy before formation.

[0015] A spacing synchronization adjustment component composed of parallelogram linkages is integrated on the rotating arm, which can drive all clamp sliders to move synchronously along the guide rail. In calibration mode, the clamp spacing is reduced to make the pole ears on the same side closely aligned, maximizing the use of existing color / shape markings for efficient comparison; full-row synchronous adjustment is achieved with a single drive source, avoiding multi-motor coordination errors, and the adjustment process does not affect the horizontal posture of the clamps.

[0016] To address the characteristics of soft-pack batteries, such as low strength of the aluminum-plastic film encapsulation and the wet, soft nature of the internal cells, this invention employs a differential compensation transmission system consisting of a fixed control gear, a rotating arm, a synchronous gear, and a toothed synchronous belt. When the rotating arm rotates as a whole, the stationary control gear drives each synchronous gear to rotate in the opposite direction relative to the arm body by the same angle via the synchronous belt, thereby offsetting the attitude change and ensuring that the clamp and the battery it carries remain horizontal at all times.

[0017] To simultaneously meet the two requirements of "maintaining horizontality during posture switching" and "adjustable spacing," this invention incorporates a transmission limiting structure consisting of a limiting member and a limiting groove between the slider and the rotating arm. The limiting groove extends along the length of the rotating arm, restricting the clamp from rotating relative to the synchronous gear during rotation, ensuring effective transmission of reverse compensation motion. Furthermore, during spacing adjustment, the limiting member can slide longitudinally along the groove without obstructing the slider's movement. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the present invention; Figure 2 for Figure 1 A schematic diagram of the structure of the battery carrier; Figure 3 for Figure 1 A schematic diagram of the gear transmission structure of the battery carrier; Figure 4 for Figure 1 A diagram illustrating the positional changes of the batteries on the battery carrier. In the diagram: 1. Formation cabinet; 2. Battery carrier; 21. Base; 22. Clamp; 23. Rotating arm; 24. Control gear; 25. Synchronizing gear; 26. Synchronizing drive belt. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so as to make the technical solution of the present invention easier to understand and master. In the embodiments, it should be understood that the terms "middle," "upper," "lower," "top," "right side," "left end," "above," "back," "center," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, unless otherwise specified in this specific embodiment, the connection or fixing method between components can be achieved by bolt fixing, pin fixing, or pin connection commonly used in the prior art, etc., and therefore will not be described in detail in this embodiment.

[0020] The lithium battery formation equipment provided by this invention is mainly used in the first charge-discharge formation process of soft-pack lithium batteries, but it is not limited thereto. Without departing from the core concept of this invention, it can also be applied to the same or similar production processes such as formation, aging or capacity testing of other electrochemical devices (such as solid-state batteries, lithium-sulfur batteries or sodium-ion soft-pack batteries) with similar tab structures and high requirements for attitude control and contact reliability.

[0021] Furthermore, as is common knowledge in the field, the visual recognition system mentioned above (used for polarity determination based on tab color or shape), the formation cabinet 1 should also be equipped with a constant current and constant voltage power supply module, a restraint pressure mechanism, a thermal management system, and the basic working principle of synchronous belt / chain drive, all of which are conventional technical means in the field of battery manufacturing equipment. Therefore, this article will not elaborate on the specific circuit structure, control logic, or standard mechanical form of these common knowledge components in detail, but will only focus on the innovative mechanical structure and its collaborative working mechanism involved in this invention.

[0022] Example 1 This embodiment provides a lithium battery formation device to solve safety and performance problems caused by incorrect polarity connection during the formation process of pouch batteries. As described in the background art, the positive and negative tabs of pouch batteries are highly similar in appearance, making them extremely easy to reverse during manual or automatic feeding, causing copper current collector dissolution, gas generation and swelling, and even thermal runaway. To address the above pain points, this invention achieves a safe process flow of "calibration before formation" through a switchable clamping fixture system 22 and a high-precision synchronous transmission mechanism.

[0023] For details, see Figure 1 , Figure 2The lithium battery formation equipment includes a formation cabinet 1, which is equipped with a battery carrier 2, a base 21, and clamps 22. The clamps 22 are used for battery support and positioning. Crucially, all clamps 22 are mounted on a pair of rotating arms 23, allowing switching between a single-layer horizontal arrangement and a multi-layer vertical stacking mode. Before formation, the system first switches the clamps 22 to the multi-layer vertical stacking mode: at this time, multiple batteries on the same rotating arm 23 are arranged vertically in layers, and the electrodes on the same side of all batteries (such as all positive tabs) are precisely aligned on the same vertical line. This design greatly improves the accuracy of the visual recognition system. The camera can capture images of the entire row of tabs at once, and the AI ​​algorithm quickly determines whether there is polarity reversal. Even with manual visual inspection, the operator only needs to observe from the side to confirm consistency, significantly reducing the risk of misjudgment. The main advantage lies in leveraging the common practice in current battery production to differentiate tabs by color or shape (e.g., red for positive and blue for negative). This close, collinear arrangement allows operators to quickly compare the tab markings of the entire row of batteries from the side of the equipment to ensure consistency. If equipped with a vision system, high-contrast, unobstructed tab images can be acquired simultaneously, significantly improving calibration efficiency and accuracy. It is important to emphasize that the formation cabinet 1 of this invention does not contain image acquisition, color recognition, or logic judgment modules. Its core contribution lies in providing a mechanical configuration that facilitates external polarity consistency verification. After calibration, the fixture 22 automatically switches back to a single-layer horizontal arrangement mode, ensuring all batteries are laid flat on the same horizontal plane. This ensures vertical pressing of the formation probes, uniform distribution of restraint pressure, and facilitates the smooth horizontal discharge of trace gases generated by electrolyte decomposition, preventing air bubbles from affecting the quality of SEI film formation.

[0024] Because pouch batteries use an aluminum-plastic film encapsulation, their structural strength is far lower than that of metal-cased batteries, and the internal cells are in a "wet" and soft state after electrolyte injection. If the battery is tilted, upright, or even inverted before or during formation, the electrolyte will accumulate on the lower side under gravity, leading to uneven wetting of the electrodes—the negative electrode area will dry out and fail to form a complete SEI film, while the other side will experience increased side reactions due to excessive electrolyte. Simultaneously, the aluminum-plastic film is prone to deformation under its own weight when not in a horizontal position, causing the tabs to shift under stress and the sealing edges to stretch, increasing the risk of leakage. Furthermore, the formation process requires uniform surface restraint pressure to suppress gas production and promote interface stability, and this pressure can only be effectively and evenly transmitted to the entire cell surface through the upper and lower pressure plates when the battery is placed horizontally. Therefore, regardless of whether it is in single-layer formation mode or multi-layer stacking calibration mode, the battery must always be kept flat to ensure formation quality, safety, and process consistency.

[0025] To achieve the core requirement of keeping the battery flat during the aforementioned mode switching, please refer to [link / reference needed]. Figure 2 , Figure 3In this invention, a control gear 24 is fixedly mounted on the base 21, and its rotation axis is strictly coaxial with the rotation axis of the rotating arm 23. Multiple synchronous gears 25 are spaced apart along the length of the rotating arm 23, and each synchronous gear 25 is rigidly connected to its corresponding clamp 22 via a transmission limiting structure. The control gear 24 and each synchronous gear 25 are connected by a toothed synchronous belt with teeth on the inner side, and the specifications of the control gear 24 and the synchronous gears 25 are identical. When the drive mechanism drives the rotating arm 23 to rotate upwards around its axis (e.g., from 0° to 90° to enter a stacking mode), the stationary control gear 24 forces each synchronous gear 25 to rotate in the opposite direction relative to the rotating arm 23 by the same angle via the synchronous belt. For example, if the rotating arm 23 rotates 90° clockwise, the synchronous gear 25 rotates 90° counterclockwise, thereby offsetting the change in tilt angle and keeping the clamp 22 horizontal. This "differential compensation" mechanism is one of the key innovations of this invention, completely solving the problems of electrode misalignment and probe slippage caused by battery tilt in traditional flipping mechanisms.

[0026] Furthermore, to ensure the reliability of synchronous transmission, a tensioning pulley is provided on the non-working side of the synchronous belt (i.e., the side not meshing with the gears). This tensioning pulley is rotatably mounted on the rotating arm 23 and applies constant pressure via a spring or eccentric shaft, continuously abutting against the synchronous belt to prevent it from loosening and skipping teeth due to long-term use. Especially in high-frequency mode switching scenarios, the tensioning pulley effectively maintains transmission accuracy, ensuring the levelness of the clamp 22 after each attitude change, meeting the requirements for high consistency formation.

[0027] Preferred, see Figure 4 In this embodiment, a spacing synchronization adjustment component is integrated on the rotating arm 23 to optimize the battery calibration effect. Specifically, the rotating arm 23 has a linear guide rail along its length, and a slider is fixedly connected to the bottom of each clamp 22, with the slider slidingly engaged with the guide rail. The spacing synchronization adjustment component adopts a parallelogram linkage mechanism: adjacent sliders are hinged together by two equal-length connecting rods to form multiple parallelogram units connected in series; all units share a single drive push rod, driven by a miniature electric cylinder. When the push rod extends, all parallelogram units deform synchronously, forcing each slider to move towards the other with the same displacement, thereby uniformly reducing the spacing between adjacent clamps 22. During the calibration stage, the system automatically adjusts the spacing to the minimum, ensuring that the same-side tabs of the entire battery array are tightly fitted along an ideal vertical line, greatly improving the visual recognition signal-to-noise ratio.

[0028] It is worth noting that, to accommodate both "pitch adjustment" and "posture maintenance" functions, this invention provides a transmission limiting structure between the clamp 22 (or a slider) and the synchronous gear 25. This transmission limiting structure includes a limiting member on the slider and a limiting groove on the rotating arm 23, or vice versa. When the clamp 22 is in a stacked mode, all limiting grooves are naturally located in the same vertical plane. During the rotation of the rotating arm 23, the limiting member is within the groove, thus reliably transmitting the rotational motion of the synchronous gear 25 to the clamp 22. During pitch adjustment, the limiting member slides longitudinally along the limiting groove, without obstructing the movement of the slider.

[0029] Finally, to reduce the overall height of battery carrier 2 and save space. See also Figure 3 , Figure 4 The base 21 is provided with a pair of rotating arms 23, which are symmetrically arranged in the same vertical plane. When all the clamps 22 are in a single-layer horizontal arrangement mode, the two rotating arms 23 are collinear and form a horizontal "I" shape, that is, the length direction of the two rotating arms 23 is collinear and they are on the same horizontal line. When switching to the stacking mode, the height of the whole machine can be compressed to about 40% of the single-arm solution because the two arms are retracted inward.

[0030] Of course, the above are just typical examples of the present invention. In addition, the present invention may have many other specific embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A lithium battery formation device, characterized in that, The device includes a formation cabinet, which is equipped with a battery carrier, a battery carrier base, and clamps. The clamps are used for supporting and positioning the battery. The clamps are arranged linearly on the base and can switch between a single-layer horizontal arrangement mode and a multi-layer vertical stacking mode on the base. Before formation, the fixture is switched to a multi-layer vertical stacking mode to calibrate the positive or negative terminals of the battery, avoiding the need for reverse installation of the battery during formation. After calibration, the fixture is switched from the multi-layer vertical stacking mode to a single-layer horizontal arrangement mode to achieve good electrical connection, uniform restraint pressure, efficient thermal management and gas discharge during formation.

2. The lithium battery formation equipment as described in claim 1, characterized in that, A rotating arm is provided on the base, and the clamp is installed on the rotating arm. The rotating arm drives the entire clamp to change its posture in space. The clamp remains horizontal on the rotating arm, ensuring that the battery on the clamp is always in a flat position during mode switching. When the fixture is in a multi-layer vertical stacking mode, multiple batteries on the same rotating arm are arranged in layers along the vertical direction, and the electrodes on the same side of all batteries are located on the same vertical line, which facilitates polarity consistency verification through a visual recognition system or manual means. When switching to a single-layer horizontal arrangement mode, all cells are located in the same horizontal plane to ensure stable probe contact, uniform distribution of restraint pressure, efficient heat conduction path, and timely discharge of gases generated by electrolyte decomposition during the formation process.

3. The lithium battery formation equipment as described in claim 2, characterized in that, A control gear is fixedly mounted on the base, and the axis of the control gear is coaxial with the axis of rotation of the rotating arm. Multiple synchronous gears are linearly arranged on the rotating arm along its length. The synchronous gears are rotatably mounted on the rotating arm. The control gear and each synchronous gear are respectively connected to the corresponding clamp. The control gear and the synchronizing gear are connected by a synchronous transmission belt. When the rotating arm rotates around its own rotation axis, the control gear remains stationary and drives each synchronous gear to rotate in the opposite direction relative to the rotating arm through the synchronous transmission belt, so that each clamp always maintains a horizontal posture during the overall movement of the rotating arm.

4. The lithium battery formation equipment as described in claim 3, characterized in that, The control gear and the synchronizing gear have the same specifications; the synchronizing transmission belt is a toothed synchronizing belt or a transmission chain, and the toothed synchronizing belt has teeth on the inside.

5. The lithium battery formation equipment as described in claim 3, characterized in that, A tensioning pulley is provided on the transmission path of the synchronous transmission belt. The tensioning pulley is rotatably mounted on the rotating arm and abuts against the non-working side of the synchronous transmission belt to apply tension to the synchronous transmission belt and ensure that each synchronous gear and the synchronous transmission belt maintain meshing transmission.

6. The lithium battery formation apparatus according to any one of claims 3 to 5, characterized in that, The rotating arm is provided with a guide rail along its own length direction, the clamp is fixedly connected to the slider, and the slider and the guide rail are adapted to each other; The rotating arm is also equipped with a spacing synchronization adjustment component, which is connected to the slider transmission. The spacing synchronization adjustment component can synchronously drive all sliders to move along the guide rail to adjust the spacing between adjacent clamps. When the clamps are in a multi-layer vertical stacking mode, the spacing between adjacent clamps is reduced by the spacing synchronization adjustment component, so that the electrodes on the same side of each battery are closely aligned in the vertical direction, which facilitates polarity consistency verification through a visual recognition system or manual means.

7. The lithium battery formation equipment as described in claim 6, characterized in that, A transmission limiting structure is provided between the clamp and the synchronous gear. The transmission limiting structure includes a limiting member provided on the slider and a limiting groove provided on the rotating arm, or vice versa. By means of the transmission limiting structure, when the rotating arm rotates around its axis, the relative rotation of the clamp with respect to the synchronous gear is restricted, thereby ensuring that the clamp rotates synchronously in the opposite direction with the synchronous gear and maintaining the horizontal posture of the clamp. When the fixture is in a multi-layer vertical stacking mode, the limiting grooves are on the same vertical line and the vertical line is parallel to the length direction of the rotating arm, so that the spacing synchronization adjustment component can adjust the fixture spacing without interfering with the limiting function.

8. The lithium battery formation equipment as described in claim 7, characterized in that, The base is provided with a pair of rotating arms, and the two rotating arms are symmetrically arranged in the same vertical plane along the vertical direction; When all fixtures are in a single-layer horizontal arrangement, the length directions of the two rotating arms are collinear and on the same horizontal line. Reduce the overall vertical height occupied by the battery carrier when it switches to a multi-layer vertical stacking mode.

9. The lithium battery formation equipment as described in claim 6, characterized in that, The spacing synchronization adjustment component is a parallelogram linkage mechanism. Each linkage mechanism is composed of two links of equal length hinged together and connected to two adjacent sliders.

Images