Novel liquid-cooled anti-deformation battery cell, battery pack and automobile

Abstract

The utility model provides a novel liquid cooling anti -deformation electric core, battery pack and car relates to the electric core technical field, include: electric core body, the side surface of electric core body is equipped with the buffer layer, fills in the buffer layer with liquid cooling material. Advantageous effect is through the ingenious increase buffer layer outside lithium battery, has solved the security problem after the deformation of the lithium battery that is easy to deform, and has increased the liquid cooling material in the buffer layer, therefore has solved the temperature rise of electric core charging and discharging process, makes the electric core use temperature in the appropriate temperature range, prolongs the service life.

Description

Technical Field

[0001] This utility model relates to the field of battery cell technology, and in particular to a novel liquid-cooled anti-deformation battery cell, battery pack, and automobile. Background Technology

[0002] With the booming development of the global new energy vehicle industry and the growing market demand for low-carbon travel, lithium-ion battery technology, as a core power unit, continues to attract industry attention. Although lithium-ion batteries have become the mainstream choice due to their environmental friendliness and long cycle life, their safety performance in practical applications still faces two major technical challenges:

[0003] I. Structural stability issues under conditions of mechanical abuse

[0004] To maximize energy density, existing square / pouch battery cells generally employ thin-walled casing designs. When a vehicle experiences a chassis collision, road bumps, or bottoming-out accident, the battery module is prone to irreversible deformation due to external pressure. This deformation not only causes the edges of the stacked electrodes inside the cell to be compressed and puncture the separator, forming a short circuit, but experiments have also shown that when the casing indentation exceeds 50% of the gap between the electrodes and the separator, the self-discharge rate will increase exponentially, potentially triggering a thermal runaway chain reaction in extreme cases.

[0005] II. Thermal Management Bottlenecks in Fast Charging Scenarios

[0006] Due to the limitations of traditional passive cooling systems, the internal temperature gradient of the battery cell increases significantly during high-rate charging. More seriously, structural deformation can further disrupt the uniformity of heat conduction within the battery cell, causing local hotspot temperatures to exceed the critical value for SEI film decomposition, exacerbating heat generation from side reactions, and forming a positive feedback loop of "temperature-side reaction".

[0007] This electromechanical coupling failure mechanism has become a key constraint on improving the performance of lithium batteries, and breakthroughs are urgently needed through multidisciplinary collaborative design. Utility Model Content

[0008] To address the problems existing in the prior art, this utility model provides a novel liquid-cooled anti-deformation battery cell, including a battery cell body, a buffer layer provided on the side of the battery cell body, and the buffer layer being filled with liquid cooling material.

[0009] Preferably, the buffer layer is provided with a plurality of partitions perpendicular to the length direction of the buffer layer.

[0010] Preferably, the liquid cooling material filling the buffer layer accounts for 60%-90% of the volume of the buffer layer.

[0011] Preferably, the liquid cooling material is a mixture of water and ethylene glycol.

[0012] Preferably, the buffer layer is disposed on the long side of the battery cell body.

[0013] Preferably, the partition is corrugated.

[0014] Preferably, the buffer layer is made of aluminum alloy.

[0015] Preferably, the buffer layer is provided with a plurality of energy-absorbing plates perpendicular to the length direction of the buffer layer.

[0016] This utility model also provides a battery pack, including the novel liquid-cooled anti-deformation battery cell as described above.

[0017] This utility model also provides an automobile, including the battery pack as described above.

[0018] The above technical solution has the following advantages or beneficial effects:

[0019] By cleverly adding a buffer layer to the outside of the lithium battery, the safety problem of easily deformed lithium batteries after deformation is solved. Furthermore, liquid cooling materials are added to the buffer layer, thus solving the temperature rise during the charging and discharging process of the battery cell, keeping the battery cell operating temperature within a suitable range, and extending its service life. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of the side of the novel liquid-cooled anti-deformation battery cell in a preferred embodiment of the present invention.

[0021] Figure 2 In a preferred embodiment of this utility model, a front cross-sectional view of the novel liquid-cooled anti-deformation battery cell is shown. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within its scope.

[0023] In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a novel liquid-cooled anti-deformation battery cell is provided, such as... Figure 1 The diagram shows a battery cell body 2, with a buffer layer 1 on the side of the battery cell body 2, and the buffer layer 1 is filled with liquid cooling material.

[0024] Specifically, existing lithium battery cell casings use a single-layer casing. During vehicle installation, they are easily deformed by pressure when the car chassis is bumped, resulting in obvious dents on the sides of the casing. These dents affect the normal use of the cell. If the impact is more severe, the electrodes inside the cell may come into contact with the casing, or the electrodes may squeeze against each other, causing a short circuit and posing a safety risk.

[0025] Therefore, in this invention, by adding a buffer layer 1 to the outer sides of the casing of the battery cell body 2, the energy is absorbed by the buffer layer 1 when the battery cell is bumped or squeezed. The buffer layer 1 deforms upon impact but does not affect the internal structure of the battery cell. When this newly designed battery cell is assembled into a battery pack and installed in a vehicle, it provides excellent safety protection. For example, if a stone falls on the bottom of the battery pack while driving, the casing of a normal battery cell will deform, but in this invention, only the outer buffer layer deforms; the battery cell body inside the buffer layer does not deform, preventing compression of the battery cell body and significantly improving safety performance.

[0026] Furthermore, by filling the buffer layer 1 with liquid cooling material, the temperature rise during the charging and discharging process of the battery cell is resolved. This keeps the battery cell's operating temperature within a suitable range, extending its service life.

[0027] The preferred embodiment of this utility model is as follows: Figure 2 The buffer layer 1 shown is provided with a plurality of partitions 11 perpendicular to the length direction of the buffer layer 1.

[0028] Specifically, the buffer layer 1 is provided with multiple partitions 11 to divide the buffer layer into multiple compartments 12. Each compartment 12 is filled with liquid cooling material to prevent the liquid cooling material from being concentrated at one end of the buffer layer 1 during the acceleration and deceleration of the vehicle or when the battery position is shifted, resulting in uneven heat dissipation.

[0029] In a preferred embodiment of this invention, the liquid cooling material filling the buffer layer 1 accounts for 60%-90% of the volume of the buffer layer.

[0030] Specifically, in this embodiment, the buffer layer is not 100% filled with liquid cooling material; instead, a non-full-fill liquid storage structure is formed within a 60%-90% filling range. This design fully utilizes the surface tension effect of fluids. When the battery pack is subjected to external mechanical impact, the unfilled 10%-40% buffer space can effectively absorb the kinetic energy generated by the deformation of the liquid cooling material. By establishing a dynamic pressure balance mechanism, the maximum instantaneous pressure is reduced to below a safe threshold (e.g., <0.15MPa), preventing the liquid cooling material from directly spraying out of the buffer layer and leaking during shell deformation, thus avoiding contamination of the entire battery pack.

[0031] Furthermore, considering the thermal expansion and contraction of liquid cooling materials, the reserved space can accommodate a volume change of approximately 12%-18% under operating conditions ranging from -20°C to 80°C. Under extreme temperature shocks (such as thermal runaway at 150°C), it ensures that the pressure in the buffer layer is always maintained below the burst threshold (e.g., 0.8 MPa).

[0032] In a preferred embodiment of this invention, the liquid cooling material is a mixture of water and ethylene glycol.

[0033] Specifically, liquid cooling materials can use mixtures such as water and ethylene glycol, which offer a good balance between cost and cooling effect. Alternatively, other liquid cooling materials can be used, such as propylene glycol (PG) aqueous solution, which has the advantages of being less toxic and biodegradable than ethylene glycol (EG), and has an adjustable freezing point (e.g., a 40% propylene glycol aqueous solution has a freezing point of approximately -30°C), making it suitable for scenarios with high environmental protection requirements. Liquid cooling materials can also use synthetic oil-based coolants such as polyalphaolefin (PAO) and alkylbenzene oil, which have the advantages of high boiling points (>200°C), no risk of electrical conductivity, and are suitable for high-temperature and high-voltage environments.

[0034] In a preferred embodiment of this utility model, the buffer layer 1 is disposed on the long side of the battery cell body 2.

[0035] Specifically, in this embodiment, multiple battery cells are usually stacked in the battery pack, so the areas prone to collision are usually the long side of the battery cell. The buffer layer is set on the long side of the battery cell body, which can not only achieve collision buffering, but also save material costs.

[0036] The preferred embodiment of this utility model is as follows: Figure 2 The partition 11 shown is wavy.

[0037] Specifically, in this embodiment, a wave-shaped partition 11 is provided to increase the energy absorption effect during collision. The wave shape on the partition 11 can be formed by multiple consecutive reverse V-shaped or U-shaped basic units. When the V / U-shaped structure is subjected to axial compression, the impact kinetic energy is converted into the plastic deformation energy of the material through continuous folding of the plastic hinge, avoiding sudden fracture caused by stress concentration. Among them, the sharp corners of the V-shaped basic unit form a stable folding wave, and the specific energy absorption (SEA) can reach 15-20 kJ / kg (aluminum alloy material). The arc transition design of the U-shaped basic unit can extend the deformation stroke and improve the energy absorption efficiency by 10-15% (compared to the flat plate structure).

[0038] In a preferred embodiment of this invention, the buffer layer 1 is made of aluminum alloy.

[0039] Specifically, the buffer layer is made of aluminum alloy, which improves thermal conductivity and enhances the heat dissipation effect of the liquid cooling material on the battery cell. Alternatively, PP material can be used, which has good heat resistance and high flexural strength.

[0040] The preferred embodiment of this utility model is as follows: Figure 2 The buffer layer 1 shown is provided with a plurality of energy-absorbing plates 13 perpendicular to the length direction of the buffer layer 1.

[0041] Specifically, the buffer layer is also provided with multiple energy-absorbing plates 13, which are usually honeycomb-shaped energy-absorbing plates, but other folded shapes can also be used, such as a structure in which equilateral / isosceles triangular units are arranged periodically, forming a plastic hinge network at the vertices of the triangles. By dispersing the impact stress through multi-directional buckling, the energy absorption effect during the collision can be further increased.

[0042] This utility model also provides a battery pack, including the novel liquid-cooled anti-deformation battery cell as described above.

[0043] This utility model also provides an automobile, including the battery pack as described above.

[0044] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.

Claims

1. A novel liquid-cooled, deformation-resistant battery cell, characterized in that, It includes a battery cell body, and a buffer layer is provided on the side of the battery cell body, and the buffer layer is filled with liquid cooling material.

2. The novel liquid-cooled anti-deformation battery cell according to claim 1, characterized in that, The buffer layer is provided with multiple partitions perpendicular to the length direction of the buffer layer.

3. The novel liquid-cooled anti-deformation battery cell according to claim 1, characterized in that, The liquid cooling material filling the buffer layer accounts for 60%-90% of the volume of the buffer layer.

4. The novel liquid-cooled anti-deformation battery cell according to claim 1, characterized in that, The buffer layer is disposed on the long side of the battery cell body.

5. The novel liquid-cooled anti-deformation battery cell according to claim 2, characterized in that, The partition is wavy.

6. The novel liquid-cooled anti-deformation battery cell according to claim 1, characterized in that, The buffer layer is made of aluminum alloy.

7. The novel liquid-cooled anti-deformation battery cell according to claim 1, characterized in that, The buffer layer is provided with multiple energy-absorbing plates perpendicular to the length direction of the buffer layer.

8. A battery pack, characterized in that, Including the novel liquid-cooled anti-deformation battery cell as described in any one of claims 1-7.

9. A car, characterized in that, Includes the battery pack as described in claim 8.

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