Lithium battery pack protection structure

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a lithium battery pack protection structure, a bottom plate, a side frame and a top plate are sequentially and fixedly connected through bolts from bottom to top, a battery module is arranged in the side frame, a socket is arranged on the front side of the side frame, the bottom plate is hollow, and a honeycomb plate is arranged in the hollow part; inner ribs are evenly distributed on the inner sides of the side frames, inner layer plates are movably arranged between the inner ribs and the side frames, and conduction structures are arranged at the four corners of each inner layer plate to conduct impact force. The hollow bottom plate is arranged, the honeycomb plate is arranged in the bottom plate, so that the impact resistance of the bottom plate is enhanced, in addition, the inner ribs are arranged between the side frame and the inner layer plate, the strength of the side plate is enhanced, the inner layer plate is arranged on the inner sides of the inner ribs, and the conduction structure is arranged at the corner position of the inner layer plate, so that when the side frame is sunken, the honeycomb plate is prevented from falling off. Impact force can be conducted to the follow-up process through the inner layer plate and the conduction structure, and the impact force is dispersed to a certain degree.

Description

Technical Field

[0001] This application relates to the technical field of lithium batteries, and in particular to protective structures for lithium battery packs. Background Technology

[0002] In today's era of increasing reliance on lithium batteries, lithium battery packs are widely used in electric vehicles, energy storage devices, and many other fields. The safety of lithium battery packs is of paramount importance. Impacts can lead to minor issues such as electrolyte leakage, affecting battery performance and lifespan; or more serious incidents such as fires and explosions, causing significant loss of life and property.

[0003] Currently, the external protection of lithium battery packs typically uses metal layers forming a rectangular box structure. This protective structure can provide basic protection for the battery to some extent, preventing minor collisions and scratches. However, the metal layer structure has significant limitations. Its deformation range is limited, making it difficult to absorb energy through effective deformation when subjected to greater impacts, and its energy conduction capacity is also relatively limited. This makes the layer structure particularly vulnerable to high-intensity impacts, failing to provide reliable safety for lithium battery packs.

[0004] With the continuous expansion of lithium battery applications and the increasing demands for safety, existing lithium battery pack protection structures are no longer sufficient to meet practical needs. Therefore, there is an urgent need for an innovative protection structure to enhance the lithium battery pack's resistance to impacts, effectively reduce safety risks, and ensure the safe and stable operation of the lithium battery pack in various complex environments. This application provides a lithium battery pack protection structure. Utility Model Content

[0005] To address the aforementioned issues, this application provides a protective structure for lithium battery packs.

[0006] The lithium battery pack protective structure provided in this application consists of a bottom plate, a side frame, and a top plate that are bolted together from bottom to top. The battery module is placed inside the side frame, and a socket is provided on the front. The characteristic feature is that the bottom plate is hollow inside, and a honeycomb plate is provided in the hollow part.

[0007] The inner side of the side frame is evenly distributed with inner ribs, and an inner plate is movable between the inner ribs and the side frame. The four corner positions of the inner plate are provided with a transmission structure to transmit the impact force. The other side of the inner rib is welded with a protective plate.

[0008] By setting a hollow base plate and installing honeycomb panels inside the base plate, the impact resistance of the base plate is enhanced. In addition, internal ribs are set between the side frame and the inner layer plate to strengthen the side plate. An inner layer plate is set inside the internal ribs, and a transmission structure is set at the corner of the inner layer plate. This allows the impact force to be transmitted to the subsequent parts through the inner layer plate and the transmission structure when the side frame is dented, thus dispersing the impact force to a certain extent.

[0009] Preferably, the conductive structure includes a first guide plate and a second guide plate, which are arranged in a cross pattern, and both are welded to the adjacent side walls of the inner layer plate on both sides.

[0010] Preferably, the inner rib has a movable groove on one side of the side frame, and the inner layer plate is disposed in the movable groove.

[0011] Preferably, through slots are provided at the four corners of the protective plate to correspond to the conductive structure.

[0012] Preferably, the honeycomb panel fills the hollow portion of the base plate.

[0013] In summary, this application includes the following beneficial technical effects:

[0014] By setting a hollow base plate and installing honeycomb panels inside the base plate, the impact resistance of the base plate is enhanced. In addition, internal ribs are set between the side frame and the inner layer plate to strengthen the side plate. An inner layer plate is set inside the internal ribs, and a transmission structure is set at the corner of the inner layer plate. This allows the impact force to be transmitted to the subsequent parts through the inner layer plate and the transmission structure when the side frame is dented, thus dispersing the impact force to a certain extent. Attached Figure Description

[0015] Figure 1 It is the isometric drawing in Embodiment 1 of this application;

[0016] Figure 2 This is the bottom-view isometric drawing from Embodiment 1 of this application;

[0017] Figure 3 This is an internal structure diagram of Embodiment 1 of this application;

[0018] Figure 4 This is an exploded view of Embodiment 1 of this application;

[0019] Figure 5 This is a partial cross-sectional view of Embodiment 1 of this application;

[0020] Figure 6 This is a longitudinal sectional view of Embodiment 1 of this application;

[0021] Figure 7 This is a partial sectional view of the base plate in Embodiment 1 of this application;

[0022] Figure 8 This is a longitudinal sectional view of the base plate in Embodiment 1 of this application;

[0023] Figure 9 This is a structural diagram of the battery pack arrangement in Embodiment 1 of this application.

[0024] Explanation of reference numerals in the attached drawings: 1. Side frame; 2. Top plate; 3. Bottom plate; 31. Honeycomb panel; 4. Socket; 5. Protective plate; 51. Through groove; 6. Conductive structure; 61. Guide plate one; 62. Guide plate two; 7. Inner layer plate; 71. Long side; 72. Short side; 8. Inner rib; 81. Movable groove. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1 - Figure 8 This application will be described in further detail.

[0026] Lithium battery pack protection structure, refer to Figure 1 - Figure 8 This is an embodiment of the present application. In this embodiment, a protective armor is provided on the outside of the lithium battery pack. The armor consists of a side frame 1, a top plate 2, and a bottom plate 3. The lithium batteries are placed on the inside and connected to each other by a busbar, which is ultimately connected to an external socket 4. The upper and lower sides of the side frame 1 are integrally formed with skirts. The skirts have openings that fit into the through holes on the top plate 2 and the bottom plate 3, thereby allowing them to be locked together using bolts.

[0027] The base plate 3 is hollow inside, and its inner side is completely filled with honeycomb panels 31. Taking the base plate 3 as an example, with an aluminum alloy material, a top and bottom thickness of 10mm, and a honeycomb panel 31 wall thickness of 2mm, the total thickness of the honeycomb panel 31 layers is 20mm. The formula for the critical stress of axial compression in a honeycomb sandwich structure is as follows: For a honeycomb sandwich structure, the critical stress of axial compression instability can be calculated using a modified Euler formula. Among them: E eq The equivalent elastic modulus of a honeycomb structure, for aluminum alloy honeycomb (regular hexagonal honeycomb), (t is the honeycomb wall thickness of 2mm, b is the honeycomb side length of about 5.7mm, and is the elastic modulus of aluminum alloy material, such as the modulus of 6061 aluminum alloy of about 68.9GPa); L: structural compression length; h: total thickness of the laminated structure (upper and lower bottom plates 3 thickness 10mm*2 + honeycomb structure thickness 20mm).

[0028] Since the battery pack is typically subjected to impact forces from bottom to top, when subjected to an upward impact, the impact force first acts on the lower base plate 3, and is transmitted to the honeycomb structure through the honeycomb walls, causing bending and compression deformation of the honeycomb walls. Simultaneously, the upper and lower base plates 3 participate in the deformation together. The multi-layer (2-layer honeycomb) characteristics of the honeycomb structure allow it to disperse the impact force through stepwise deformation, forming a "buffering-dispersion-absorption" energy dissipation chain. Energy absorption formula: Total energy absorption Ehoneycomb = Ebase plate 3 deformation + Ehoneycomb wall deformation, where the deformation energy of the base plate 3 is Ehoneycomb 底板变形 =∫σ·ε·V 底板 dV(σ is stress, ε is strain, V) 底板 (Base plate 3 volumes), honeycomb wall deformation energy (k i For the equivalent stiffness of a single honeycomb wall, δ i (This refers to the amount of deformation). Compared to a 20mm pure aluminum alloy structure, the impact force acts directly on the plate, and the material responds with overall tensile, compressive, or bending deformation. Stress concentration is significant, and energy absorption depends on the material's own plastic deformation capacity. The energy absorption formula, given a plate thickness of 20mm, is the volume of material involved in the deformation, V. 板 The base plate 3, which is much smaller than the total volume of the honeycomb structure, has a lower energy absorption capacity than the structure with the honeycomb panel 31 built in. Therefore, the base plate 3 structure with the honeycomb panel 31 in the middle adopted in this application can effectively resist the impact force from below.

[0029] Multiple inner ribs 8 are uniformly welded to the inner side of the side frame 1. A movable groove 81 is also provided between the inner ribs 8 and the side frame 1. The purpose is to provide a movable inner layer plate 7 on its inner side. Guide plates 61 and 62 are cross-welded at the four corners of the inner layer plate 7. The guide plates 61 and 62 combine to form a conductive structure 6, which is used to transfer the impact force received on the long or short side to other parts, thereby achieving the effect of dispersing the impact force. A protective plate 5 is also welded to the side of the inner rib 8 where the movable groove 81 is not provided. In this way, a protective layer is formed between the side frame 1 and the protective plate 5. A through groove 51 is provided on the protective plate 5 to leave enough space for the guide plates 61 and 62. Under the action of the inner ribs 8, the external impact force is further dispersed, thereby ensuring the safety of the internal battery.

[0030] Combination Figures 3-5 Assuming the impact force on the side frame 172 is F, the number of internal ribs 8 is n, the intersection angle between guide plate 1 61 and guide plate 2 62 is 2θ (take the common θ = 45°, that is, the intersection angle is 90°), and the dispersion coefficient of the guard plate 5 on the impact force is k (assuming k is 0.8).

[0031] 1. Initial dispersion of internal reinforcement

[0032] The impact force is evenly distributed among the n internal ribs, and the force on each internal rib is: F 内筋=F / n,

[0033] If F = 1000N and n = 10, then F 内筋 =100N.

[0034] 2. Secondary transfer via guide plate

[0035] The guide plate distributes the force according to the principle of force decomposition. The force on a single guide plate is as follows:

[0036] Substitute the values:

[0037] 3. The protective plate 5 is finally dispersed.

[0038] Total stress on guard plate 5: F 护板 =k*n*F 导板 ;

[0039] Substituting k = 0.8, n = 10, F 导板 70.7N:F 护板 =0.8 * 10 * 70.7 = 565.6 N;

[0040] Residual impact force F 剩余 =1000-565.6=424.4N.

[0041] Since there is welding between the protective plate 5 and the inner rib 8, the protective plate 5 will deform further to resist the impact force. At this time, the inward impact force will be further reduced, thus providing good protection for the internal battery. If a material with a higher dispersion coefficient is used, the number of inner ribs 8 is increased, and the θ value is changed, the impact resistance can be further improved. These can be adjusted according to the actual application scenario based on the structure of this application.

[0042] The foregoing description of exemplary embodiments of the lithium battery pack protection structure provided by this disclosure refers to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure, which is determined by the appended claims.

Claims

1. A lithium battery pack protective structure, comprising a base plate (3), a side frame (1), and a top plate (2) bolted together from bottom to top, wherein a battery module is housed inside the side frame (1), and a socket (4) is provided on the front, characterized in that: The bottom plate (3) is hollow inside, and a honeycomb panel (31) is installed in the hollow part; The inner side of the side frame (1) is evenly distributed with inner ribs (8), and an inner plate (7) is movable between the inner ribs (8) and the side frame (1). The four corners of the inner plate (7) are provided with a transmission structure (6) to transmit the impact force. The other side of the inner ribs (8) is welded with a protective plate (5).

2. The protective structure according to claim 1, characterized in that: The conductive structure (6) includes a first guide plate (61) and a second guide plate (62). The first guide plate (61) and the second guide plate (62) are arranged in a cross pattern, and both are welded to the adjacent side walls of the inner layer plate (7) on both sides respectively.

3. The protective structure according to claim 1, characterized in that: The inner rib (8) has a movable groove (81) on one side of the side frame (1), and the inner layer plate (7) is set in the movable groove (81).

4. The protective structure according to claim 1, characterized in that: The protective plate (5) has through slots (51) at each of the four corners corresponding to the conductive structure (6).

5. The protective structure according to claim 1, characterized in that: The honeycomb panel (31) fills the hollow part of the base plate (3).

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