Clamping mechanism and control method for battery cycling test

Abstract

The present invention discloses a clamping mechanism and a control method for battery cycle testing. The clamping mechanism includes: a base; a mounting plate provided on the base; a movable plate movably provided between the mounting plate and the base, and the battery is mounted between the movable plate and the base. Wherein, an elastic member is provided between the mounting plate and the movable plate, and two ends of the elastic member are respectively cooperated with the mounting plate and the movable plate, and the elastic member extends along a direction inclined to the movable plate. According to the clamping mechanism for battery cycle testing of the embodiment of the present invention, through the non-linear variable stiffness structural form, the battery can always be under the action of a comfortable pressure during the cycle testing, and the improvement effect of the comfortable pressure on the battery cycle performance can be exerted; the influence of the clamping mechanism on the force received by the battery can be avoided, and it is ensured that as the number of charge and discharge cycles of the battery increases, the change in the force caused by the expansion of the battery still does not exceed the range of the comfortable pressure, thereby ensuring the cycle life of the battery; the overall structure is simple and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of battery testing, and in particular, to a clamping mechanism and a control method for battery cycle testing. Background Art

[0002] In the related art, during the charge and discharge cycle test of lithium-ion batteries, appropriate pressure is beneficial to reducing the loss of active lithium, slowing down the attenuation rate of battery capacity, and improving the cycle life of lithium-ion batteries. However, when the pressure exceeds a certain value, continuing to increase the pressure will instead cause the battery cycle life to decline. That is, there is a comfortable pressure range for lithium-ion battery cycling, and within this pressure range, the best cycling performance can be demonstrated.

[0003] However, the existing charge and discharge cycle test of lithium-ion batteries has certain limitations. For example, during the free cycle test, there is no external constraint, and the external pressure of the battery is always zero, so the improvement effect of the comfortable pressure on the battery cycling performance cannot be exerted; during the constant-spacing cycle test, it is difficult to ensure a constant spacing due to the deformation of the clamping plate, and as the number of cycles increases, the expansion force of the battery will increase and exceed the range of the comfortable pressure; during the constant-pressure cycle test, when using the form of placing heavy objects, there is a problem that different pressures cannot be freely adjusted and the application range is limited, and when using the form of an automatic pressure control system, there are problems of complex structure and high cost, so there is room for improvement. Summary of the Invention

[0004] In view of this, the present invention aims to provide a clamping mechanism for battery cycle testing, and the clamping mechanism can keep the battery in a comfortable pressure range for cycle testing.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows:

[0006] A clamping mechanism for battery cycle testing, comprising: a base; a mounting plate provided on the base; a movable plate movably provided between the mounting plate and the base, and the battery is mounted between the movable plate and the base. Wherein, an elastic member is provided between the mounting plate and the movable plate, two ends of the elastic member are respectively engaged with the mounting plate and the movable plate, and the elastic member extends along a direction inclined to the movable plate.

[0007] According to the clamping mechanism for battery cycle testing of the embodiment of the present invention, the force received by the battery satisfies the conditional formula:

[0008] Wherein, F is the force applied to the battery, n is the number of elastic members, k is the elastic coefficient of the elastic members, x is the length of the elastic members in the free state, b is the distance between the movable plate and the mounting plate when the elastic members are in the free state, α is the angle between the elastic members and the movable plate when the elastic members are in the free state, and Δb is the change in the distance between the movable plate and the mounting plate.

[0009] According to the clamping mechanism for battery cycling test of an embodiment of the present invention, the force applied to the battery first increases and then decreases as the change in the distance between the movable plate and the mounting plate increases.

[0010] According to the clamping mechanism for battery cycling test of an embodiment of the present invention, it further includes: a sliding member. The mounting plate has a sliding groove, the sliding member is disposed in the sliding groove, one end of the elastic member is connected to the sliding member, and the other end of the elastic member is connected to the movable plate. Wherein, the sliding member can be fixed in the sliding groove by a fastener.

[0011] In some examples, the sliding groove extends from the center of the mounting plate to the edge of the mounting plate.

[0012] According to the clamping mechanism for battery cycling test of an embodiment of the present invention, there are multiple elastic members, and the multiple elastic members are symmetrically arranged.

[0013] According to the clamping mechanism for battery cycling test of an embodiment of the present invention, the base includes a bottom plate and guide posts. The guide posts are disposed on the bottom plate. The mounting plate is matched with the guide posts and the mounting plate can move along the extending direction of the guide posts. Wherein, the mounting plate can be fixedly connected to the bottom plate by a fastener.

[0014] In some examples, the movable plate has a mating hole, and the guide post is inserted and mated with the mating hole.

[0015] Compared with the prior art, the clamping mechanism for battery cycling test of the present invention has the following advantages:

[0016] According to the clamping mechanism for battery cycling test of an embodiment of the present invention, by providing a movable plate and elastic members to form a non-linear variable stiffness structural form, the battery can always be under the action of a comfortable pressure during the cycling test, giving play to the improvement effect of the comfortable pressure on the battery cycling performance; avoiding the influence of the clamping mechanism on the force of the battery, ensuring that as the number of charge and discharge cycles of the battery increases, the change in force caused by the expansion of the battery still does not exceed the range of the comfortable pressure, ensuring the cycling life of the battery; the overall structure is simple, and no other equipment is required, with low cost and wide application range.

[0017] Another object of the present invention is to provide a control method for a clamping mechanism for battery cycle testing. The clamping mechanism is the clamping mechanism for battery cycle testing according to the embodiments of the present invention. The control method includes: controlling the mounting plate to move towards the battery, the movable plate abuts against the battery, and the elastic member is in a free state; controlling the mounting plate to continue to move towards the battery, the elastic member is in a compressed state, and a first pressure acts on the battery.

[0018] According to the control method for the clamping mechanism for battery cycle testing according to the embodiments of the present invention, the first pressure is the minimum value of the comfortable pressure of the battery.

[0019] Compared with the prior art, the advantages of the control method for the clamping mechanism for battery cycle testing described in the present invention are the same as those of the clamping mechanism for battery cycle testing, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 is a schematic structural diagram of a clamping mechanism for battery cycle testing according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram showing the relationship between the force received by the battery according to an embodiment of the present invention and the change in the distance between the movable plate and the mounting plate;

[0023] Figure 3 is a control method diagram of a clamping mechanism for battery cycle testing according to an embodiment of the present invention.

[0024] Description of the reference numerals:

[0025] Clamping mechanism 100, battery 200,

[0026] Base 10, bottom plate 11, guide post 12, mounting plate 20, movable plate 30, elastic member 40, sliding member 50, fastener 60. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0028] Next, reference will be made to Figures 1-3 and the embodiments will be used to describe the present invention in detail.

[0029] The clamping mechanism 100 for battery cycle testing according to an embodiment of the present invention includes: a base 10, a mounting plate 20, and a movable plate 30. The mounting plate 20 is disposed on the base 10, and the movable plate 30 is disposed between the mounting plate 20 and the base 10. The movable plate 30 can move between the base 10 and the mounting plate 20, and a battery can be installed between the movable plate 30 and the base 10 to perform charge and discharge tests.

[0030] Wherein, an elastic member 40 is provided between the mounting plate 20 and the movable plate 30. Two ends of the elastic member 40 are respectively engaged with the mounting plate 20 and the movable plate 30. The elastic member 40 extends along a direction inclined to the movable plate 30. Under the action of the elastic member 40, the movable plate 30 can constrain the battery. When the battery expands and deforms, it can drive the movable plate 20 to move, and further drive the elastic member 40 to elastically deform.

[0031] Since the extending direction of the elastic member 40 is inclined to the movable plate 30, the elastic force generated by the elastic change of the elastic member 40 forms a non-linear relationship with the movement amount of the movable plate 30. That is, in this embodiment, the battery can be constrained by a non-linear variable stiffness structural form, thereby expanding the deformable amount within a certain pressure range. Specifically, the expansion and deformation of the battery during the entire cycle test drives the movable plate 30 to move, and the elastic member 40 elastically deforms. The elastic force generated by the deformation acts on the battery, and the force received by the battery can always be within the comfortable pressure range of the battery, meeting the need for the battery to be in a comfortable pressure range during battery cycle testing.

[0032] The clamping mechanism 100 for battery cycle testing according to an embodiment of the present invention, by setting the movable plate 30 and the elastic member 40 to form a non-linear variable stiffness structural form, can make the battery always under the action of a comfortable pressure during the cycle test, exerting the improvement effect of the comfortable pressure on the battery cycle performance; avoiding the influence of the clamping mechanism 100 on the force of the battery, ensuring that as the number of charge and discharge cycles of the battery increases, the change in force caused by the expansion of the battery still does not exceed the range of the comfortable pressure, ensuring the cycle life of the battery; the overall structure is simple, without the need to rely on other equipment, with low cost and wide application range.

[0033] According to some embodiments of the present invention, the battery 200 can be a lithium-ion battery, the elastic member 40 can be a spring, the stiffness of the elastic member 40 is k, the length of the elastic member in the free state is x, the distance between the two ends of the two elastic members 40 close to the mounting plate 20 is 2a, the distance between the movable plate 30 and the mounting plate 20 when the elastic member 40 is in the free state is b, and the included angle between the elastic member 40 and the movable plate 30 when the elastic member is in the free state is α. Wherein:

[0034] a = b cotα

[0035] b = x sinα

[0036] After the movable plate 30 moves leftward by a distance Δb, the compression amount of the elastic member is Δx, and the included angle between it and the movable plate 30 becomes β. Among them:

[0037]

[0038]

[0039] From the overall force balance, it can be known that:

[0040] T = kΔx

[0041] T y = T sinβ

[0042] T is the elastic force generated by the compression of the elastic member 40 after the movable plate 30 moves a distance Δb, and T y is the component of the elastic force generated by the compression of the elastic member 40 in the left - right direction, that is, the force exerted by a single elastic member 40 on the battery. Thus, it can be obtained that:

[0043]

[0044] In this embodiment, the number of elastic members is n. According to the relationship between action and reaction, the sum of the components of the elastic forces generated by the compression of n elastic members in the left - right direction is the force exerted on the battery. Therefore, the force F exerted on the battery satisfies the conditional formula:

[0045]

[0046] Where F is the force exerted on the battery, n is the number of elastic members, k is the elastic coefficient of the elastic member, x is the length of the elastic member in the free state, b is the distance between the movable plate and the mounting plate when the elastic member is in the free state, α is the included angle between the elastic member and the movable plate when the elastic member is in the free state, and △b is the change amount of the distance between the movable plate and the mounting plate.

[0047] As Figure 2 shown, according to some embodiments of the present invention, as Δb increases, the force F shows a non - linear change characteristic of first increasing and then decreasing. That is to say, the force exerted on the battery first increases and then decreases as the change amount of the distance between the movable plate 30 and the mounting plate 20 increases.

[0048] Based on this variation characteristic, after selecting the elastic member, the length of the elastic member in the free state, and the included angle between the elastic member in the free state and the movable plate 30 according to the required stiffness coefficient, according to the comfortable pressure range of the battery, by adjusting the position of the mounting plate 20 or the movable plate 30, the battery 200 can still bear a certain comfortable pressure when there is no expansion deformation at the initial stage of the cycling test. As the number of cycles increases and the battery 200 has a large expansion deformation, the force exerted on the battery also remains within the comfortable pressure range. Thus, it is ensured that during the cycling test of the battery, regardless of whether the battery expands or deforms, the pressure acting on it can always be maintained within the comfortable pressure range.

[0049] As Figure 1 shown, according to some embodiments of the present invention, the clamping mechanism 100 further includes: a sliding member 50. The mounting plate 20 has a sliding groove, the sliding member 50 is arranged on the sliding groove, one end of the elastic member 40 is connected to the sliding member 50, and the other end of the elastic member 40 is connected to the movable plate 30. Wherein, when the sliding member 50 slides to a suitable position, the sliding member 50 can be fixed in the sliding groove by a fastener 60, thereby ensuring the stability of the sliding member 50 and preventing the movable plate 30 and the sliding member 50 from moving when the battery expands and deforms, resulting in the force on the battery not being within the comfortable pressure range.

[0050] In some specific examples, the sliding groove extends from the center of the mounting plate 20 to the edge of the mounting plate 20, that is, the sliding groove extends along the Figure 1 shown inner and outer directions. The sliding member 50 can slide back and forth in the sliding groove to change the included angle α. Wherein, after the sliding member 50 slides to a specified position, it can be fixed by a bolt. It can be understood that one end of the elastic member 40 is connected to the center of the movable member 30, and the other end is connected to the sliding member 50. Both ends of the elastic member 40 can rotate around a fulcrum respectively.

[0051] According to some embodiments of the present invention, a plurality of elastic members 40 are arranged between the mounting plate 20 and the movable plate 30, and the plurality of elastic members 40 are symmetrically arranged along the center of the movable plate 30. Thus, the component forces of the elastic forces of the elastic members 40 in the plane of the movable plate 30 can cancel each other out, preventing the movable plate 30 from shaking under the action of the elastic members 40 and affecting the stability and reliability of the overall structure.

[0052] As Figure 1As shown, according to some embodiments of the present invention, the base 10 includes a bottom plate 11 and guide posts 12. The guide posts 12 are arranged on the bottom plate 11. The mounting plate 20 cooperates with the guide posts 12, and the mounting plate 20 can move along the extension direction of the guide posts 12. Among them, when the mounting plate 20 is installed in a suitable position, the mounting plate 20 can be fixedly connected to the bottom plate 11 through a fastener 60, thereby ensuring the stability of the structure and preventing the mounting plate 20 from being driven to move when the battery expands and deforms, so that the battery cannot be under a comfortable pressure range.

[0053] In some examples, the movable plate 30 has a mating hole, and the guide post 12 is inserted and mated with the mating hole. That is to say, the movable plate 30 cooperates with the guide post 12 through the mating hole, so that the movable plate 30 can also move along the guide post 12, thereby preventing the movable plate 30 from shaking, etc., making the overall structure more stable and reliable. Among them, when the movable plate 30 moves to a specified position, the mounting plate 20 can be fixedly connected to the base 10 through a fastener 60. During the expansion and deformation process of the battery, the movable plate 30 can move along the extension direction of the guide post 12.

[0054] According to the control method of the clamping mechanism for battery cycle testing according to an embodiment of the present invention, the clamping mechanism is the clamping mechanism for battery cycle testing according to an embodiment of the present invention. The control method includes:

[0055] S1, controlling the mounting plate to move towards the battery, the movable plate abuts against the battery, and the elastic member is in a free state;

[0056] S2, controlling the mounting plate to continue to move towards the battery, the elastic member is in a compressed state, and a first pressure F1 acts on the battery.

[0057] That is to say, when the movable plate abuts against the battery, the elastic member is in a free state, and the battery is not stressed at this time. Then, when controlling the mounting plate to move towards the battery, the moving amount of the mounting plate is △b1, that is, the change amount of the distance between the movable plate and the mounting plate is △b1; since the movable plate abuts against the battery and the position of the movable plate remains unchanged, the elastic member is compressed, and the elastic force generated by the compression deformation of the elastic member acts on the battery in the opposite direction, so that the battery is subjected to a certain pressure, that is, even when the battery does not expand and deform at the initial stage of the cycle test, it still bears a certain pressure, so as to play a certain role in improving the cycle performance of the battery.

[0058] In this state, the mounting plate can be fixed to the base through a fastener to realize the fixation of the clamping mechanism, and at the same time complete the clamping work of the clamping mechanism on the battery.

[0059] Furthermore, during the battery cycle test, as the number of battery cycles increases, the battery may experience significant swelling and deformation. As the battery deforms, it drives the movable plate to move towards the mounting plate, further compressing the elastic member. The component force of the elastic force generated by the compression of the elastic member acts on the battery. As the deformation amount increases, the force acting on the battery exhibits a non-linear change characteristic of first increasing and then decreasing. That is to say, the force received by the battery first increases and then decreases as the swelling amount of the battery increases. Based on this, the force received by the battery can be kept within the comfortable pressure range of the battery, meeting the requirement that the battery is within the comfortable pressure range during the cycle test.

[0060] According to the control method of the clamping mechanism for battery cycle test of the embodiment of the present invention, the battery can always be under the action of comfortable pressure during the cycle test, exerting the improvement effect of comfortable pressure on the battery cycle performance; avoiding the influence of the clamping mechanism on the force received by the battery, ensuring that as the number of battery charge and discharge cycles increases, the change in force caused by the battery swelling still does not exceed the range of comfortable pressure, ensuring the cycle life of the battery; the overall structure is simple, the control is convenient, and there is no need to rely on other equipment, with low cost and wide application range.

[0061] According to some embodiments of the present invention, the first pressure F1 is the minimum value of the comfortable pressure of the battery, so that the battery still bears the comfortable pressure when it has not swelled and deformed at the initial stage of the cycle test, in order to exert the improvement effect of comfortable pressure on the battery cycle performance.

[0062] Further, during the battery cycle test, when the battery deforms and drives the movable plate to move towards the mounting plate, where the maximum deformation amount of the battery is △b2 - △b1, the elastic member is further compressed, and the component force of the elastic force generated by the compression of the elastic member acts on the battery. During the whole process, the maximum force received by the battery is the second pressure F2, and the second pressure F2 is the maximum value of the comfortable pressure of the battery. Thus, during the cycle test of the battery, the force received by the battery can always be within the comfortable pressure range of the battery, meeting the requirement that the battery is within the comfortable pressure range during the cycle test.

[0063] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, features defined as "first", "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0064] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "mounted", "connected" and "coupled" shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A clamping mechanism (100) for battery cycling tests, characterized in that, Comprising: Base (10); Mounting plate (20), the mounting plate (20) being provided on the base (10); Movable plate (30), the movable plate (30) being movably provided between the mounting plate (20) and the base (10), and the battery being adapted to be mounted between the movable plate (30) and the base (10), Wherein, an elastic member (40) is provided between the mounting plate (20) and the movable plate (30), two ends of the elastic member (40) being respectively engaged with the mounting plate (20) and the movable plate (30), and the elastic member (40) extending along a direction inclined to the movable plate (30); The force received by the battery satisfies the conditional formula: Wherein, F is the force applied to the battery, n is the number of elastic members, k is the elastic coefficient of the elastic members, x is the length of the elastic members in the free state, b is the distance between the movable plate and the mounting plate when the elastic members are in the free state, and α is the angle between the elastic members and the movable plate when the elastic members are in the free state. △ b is the change in the distance between the movable plate and the mounting plate; The force received by the battery first increases and then decreases as the change amount of the distance between the movable plate (30) and the mounting plate (20) increases; Further comprising: a sliding member (50), the mounting plate (20) having a sliding groove, the sliding member (50) being provided in the sliding groove, one end of the elastic member (40) being connected to the sliding member (50), and the other end of the elastic member (40) being connected to the movable plate (30), wherein the sliding member (50) can be fixed in the sliding groove by a fastener (60); The sliding groove extends from the center of the mounting plate (20) towards the edge of the mounting plate (20).

2. The clamping mechanism (100) for battery cycle testing according to claim 1, wherein, A plurality of the elastic members (40) are included, and the plurality of elastic members (40) are symmetrically arranged.

3. The clamping mechanism (100) for battery cycle testing according to claim 1, characterized in that, The base (10) includes a bottom plate (11) and a guide post (12), the guide post (12) being provided on the bottom plate (11), the mounting plate (20) being engaged with the guide post (12) and the mounting plate (20) being movable along the extending direction of the guide post (12), wherein the mounting plate (20) can be fixedly connected to the bottom plate (11) by a fastener (60).

4. The clamping mechanism (100) for battery cycling tests according to claim 3, characterized in that, The movable plate (30) has a mating hole, and the guide post (12) is inserted and mated with the mating hole.

5. A control method for a clamping mechanism used in battery cycle testing, characterized in that, The clamping mechanism is the clamping mechanism for battery cycle testing according to any one of claims 1-4, and the control method includes: Controlling the mounting plate to move towards the battery, the movable plate abuts against the battery, and the elastic member is in a free state; Controlling the mounting plate to continue to move towards the battery, the elastic member is in a compressed state, and a first pressure acts on the battery.

6. The control method of the clamping mechanism for battery cycle testing according to claim 5, characterized in that, The first pressure is the minimum value of the comfortable pressure of the battery.

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