Lithium battery flow guide structure

Abstract

The utility model discloses a lithium cell flow guide structure, its structure includes the casing, the casing both sides are equipped with positive pole and negative pole, still include, set up in the flow guide subassembly and temperature regulation unit of casing inside: the flow guide subassembly contains the metal flow guide layer and insulating interval layer of alternate lamination, the metal flow guide layer surface is equipped with array type flow guide micro -groove, temperature regulation unit contains phase change material cavity and heat conduction fin, the heat conduction fin penetrates each layer of flow guide subassembly and forms heat conduction passway with phase change material cavity. The metal flow guide layer selects 6061 aluminum alloy material quality, guarantees good electric conductivity performance simultaneously, possesses higher mechanical strength. The utility model belongs to the field of lithium cell, and specifically refers to a kind of lithium cell flow guide structure.

Description

Technical Field

[0001] This utility model belongs to the field of lithium batteries, specifically referring to a lithium battery current-conducting structure. Background Technology

[0002] With the rapid development of the new energy industry, lithium batteries, as a highly efficient and clean energy storage device, are finding increasingly wide applications. However, existing lithium battery current-conducting structures still have many technical defects in practical use, seriously affecting the performance and safety of lithium batteries. Traditional lithium batteries mostly use a single-layer current-conducting structure. Due to problems such as the skin effect during current transmission, uneven current distribution occurs, and overcharging or over-discharging can easily occur in local areas. This not only shortens the lifespan of the lithium battery but may also trigger abnormal internal chemical reactions, increasing the risk of thermal runaway.

[0003] In existing lithium batteries, the heat dissipation channels and conductive structures are usually independent, resulting in significant thermal resistance between them. This makes it difficult for heat to be quickly transferred from the conductive structure to the heat dissipation channels and dissipated. When the battery operates under high load for extended periods, internal heat accumulates continuously, causing the temperature to rise steadily. This negatively impacts the battery's charge / discharge performance and cycle life, and may even lead to battery damage. Although some lithium batteries are equipped with temperature regulation systems, the phase change materials they use have low utilization rates and sluggish temperature regulation responses. When the battery temperature suddenly rises, the phase change materials cannot absorb heat in time, making it difficult to control the battery temperature within a safe range within a short period and effectively cope with sudden temperature anomalies. Utility Model Content

[0004] The present invention mainly addresses the aforementioned technical problems.

[0005] To solve the above problems, the technical solution adopted by this utility model is as follows: The lithium battery current-guiding structure proposed by this utility model includes a housing, on both sides of which a positive electrode and a negative electrode are respectively provided, and further includes a current-guiding component and a temperature regulation unit disposed inside the housing: The flow guiding component includes alternating layers of metal flow guiding layers and insulating spacer layers, and the surface of the metal flow guiding layers is provided with an array of flow guiding microgrooves; The temperature regulation unit includes a phase change material cavity and heat conduction fins. The heat conduction fins penetrate each layer of the flow guiding assembly and form a heat conduction path with the phase change material cavity.

[0006] Furthermore, the metal conductive layer is made of 6061 aluminum alloy, which ensures good electrical conductivity while possessing high mechanical strength.

[0007] Furthermore, the array-type flow-guiding microchannels are arranged in a hexagonal honeycomb pattern, with the ratio of channel depth to channel width controlled between 1:1.5 and 1:2.5, and the spacing between adjacent microchannels is 1.2 to 1.8 times the channel width.

[0008] Furthermore, the insulating spacer layer comprises a polyimide composite material reinforced with nano-alumina.

[0009] Furthermore, the phase change material cavity is filled with a paraffin / expanded graphite composite phase change material, the phase change temperature is set at 45±2℃, and the latent heat value is ≥180J / g.

[0010] Furthermore, the heat-conducting fins are made of copper / graphene composite foil with a thickness of 0.1-0.3 mm and have a micron-level dendritic fractal structure on the surface.

[0011] The beneficial effects of this utility model by adopting the above structure are as follows: 1. The lithium battery current guiding structure proposed in this solution improves the uniformity of current density distribution through the design of a metal current guiding layer and hexagonal honeycomb current guiding microgrooves, effectively avoiding local overcharging or over-discharging and extending the service life of the lithium battery.

[0012] 2. The lithium battery current-conducting structure proposed in this solution integrates a phase change material temperature control system and high thermal conductivity fins, which can stabilize battery operating temperature fluctuations, respond quickly to temperature changes, effectively prevent thermal runaway, and improve battery operating stability and safety.

[0013] 3. The lithium battery current-conducting structure proposed in this solution uses high-strength 6061 aluminum alloy for the metal current-conducting layer and reinforced composite material for the insulating spacer layer. The overall structure has high mechanical strength and can withstand external forces such as vibration and impact, ensuring normal battery operation. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic cross-sectional view of the present invention; Figure 3 This is a schematic diagram of the first partial structure of the present invention; Figure 4 This is a schematic diagram of the second partial structure of the present invention.

[0015] Among them, 1 is the shell, 11 is the positive electrode, 12 is the negative electrode, 2 is the flow guiding component, 21 is the metal flow guiding layer, 211 is the flow guiding micro-groove, 22 is the insulating spacer layer, 3 is the temperature regulating unit, 31 is the phase change material cavity, and 32 is the heat conduction fin.

[0016] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0018] like Figure 1-4 As shown, the present invention proposes a lithium battery current guiding structure, including a shell (1), with a positive electrode and a negative electrode respectively provided on both sides of the shell. The feature is that it also includes a current guiding component (2) and a temperature regulating unit (3) disposed in the shell: the current guiding component (2) includes alternating layers of metal current guiding layer (21) and insulating spacer layer (22), and the surface of the metal current guiding layer (21) is provided with an array of current guiding microgrooves (211); the temperature regulating unit (3) includes a phase change material cavity (31) and heat conduction fins (32), and the heat conduction fins (32) penetrate through each layer of the current guiding component and form a heat conduction path with the phase change material cavity (31).

[0019] The metal conductive layer (21) is made of 6061 aluminum alloy. This material has high mechanical strength while ensuring good conductivity, and can effectively cope with vibration and impact during the operation of lithium battery.

[0020] The array-type flow-guiding microgrooves (211) are arranged in a hexagonal honeycomb pattern, with the ratio of groove depth to groove width controlled between 1:1.5 and 1:2.5, and the spacing between adjacent microgrooves is 1.2 to 1.8 times the groove width. This arrangement and size ratio can minimize the resistance during current transmission, make the current evenly distributed on the surface of the flow-guiding layer, and avoid excessive concentration of local current.

[0021] The insulating spacer layer (22) contains a polyimide composite material reinforced with nano-alumina, which has a thermal conductivity ≥1.5W / (m・K) and a breakdown voltage ≥30kV / mm. This composite material can not only effectively isolate the current between adjacent metal conductive layers to prevent short circuits, but also quickly conduct the heat generated when the battery is working, thereby improving the overall heat dissipation efficiency.

[0022] The phase change material cavity (31) is filled with paraffin / expanded graphite composite phase change material, with the phase change temperature set at 45±2℃ and the latent heat value ≥180J / g. When the battery temperature rises to the phase change temperature, the phase change material absorbs heat and undergoes a phase change, thereby stabilizing the battery temperature within a safe range and avoiding thermal runaway caused by excessive temperature. The addition of expanded graphite can significantly improve the thermal conductivity of the phase change material and accelerate the absorption and release of heat.

[0023] The heat conduction fins (32) are made of copper / graphene composite foil with a thickness of 0.1-0.3 mm and a micron-level dendritic fractal structure on the surface. Copper has excellent thermal conductivity, and the addition of graphene further improves the heat conduction efficiency. The micron-level dendritic fractal structure increases the contact area between the fins and the flow-guiding components and phase change materials, thus accelerating the heat transfer speed. Furthermore, the heat conduction fins (32) can be prepared with a graphene layer on the surface of the copper foil by chemical vapor deposition to achieve the best heat conduction effect.

[0024] In practical use, the current-guiding component is composed of five layers of 6061 aluminum alloy current-guiding layer (21) and a nano-alumina / polyimide composite insulating layer (22) stacked alternately. The porosity of the 6061 aluminum alloy current-guiding layer gradually changes from 20% to 30% along the current direction, with the pore diameter controlled between 80-150 μm. Hexagonal honeycomb-shaped array-type current-guiding microgrooves (211) are processed on the surface of the metal current-guiding layer using laser engraving. The microgrooves are 0.2 mm deep, 0.3 mm wide, and the spacing between adjacent microgrooves is 0.4 mm (1.33 times the groove width). The nano-alumina / polyimide composite insulating layer has a thickness of 0.1 mm, a thermal conductivity of 1.6 W / (m·K), and a breakdown voltage of 32 kV / mm. The metal current-guiding layer and the insulating spacer layer are alternately stacked using a hot-pressing composite process to form a complete current-guiding component.

[0025] The phase change material cavity (31) is located inside the side wall of the shell (1), and the cavity thickness is 5 mm. An octadecane / graphite composite phase change material (the mass ratio of octadecane to graphite is 9:1) with a phase change temperature of 45℃ and a latent heat value of 185 J / g is filled into the phase change material cavity. The heat conduction fins (32) are made of copper foil with a thickness of 0.2 mm. A graphene layer with a thickness of 50 nm is prepared on the surface of the copper foil by chemical vapor deposition. Then, a micron-level dendritic fractal structure is processed on the surface of the copper / graphene composite foil by photolithography and etching. The branch angle of the fractal structure is 55° and the number of layers is 3. The heat conduction fins are vertically inserted through each layer of the flow guiding component. One end of the fin is inserted into the phase change material of the phase change material cavity to form a heat conduction path.

[0026] The prepared flow guiding component (2) and temperature regulation unit (3) are installed inside the housing (1) to ensure that the position of each component is accurate and the connection is tight; then the housing is sealed to complete the assembly of the entire lithium battery flow guiding structure.

[0027] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A lithium battery current-conducting structure, comprising a housing (1), wherein a positive electrode and a negative electrode are respectively disposed on both sides of the housing, characterized in that, It also includes a flow guiding assembly (2) and a temperature regulating unit (3) disposed within the housing: The flow guiding component (2) includes alternating layers of metal flow guiding layer (21) and insulating spacer layer (22), and the surface of the metal flow guiding layer (21) is provided with an array of flow guiding microgrooves (211). The temperature regulation unit (3) includes a phase change material cavity (31) and heat conduction fins (32). The heat conduction fins (32) penetrate each layer of the flow guide assembly and form a heat conduction path with the phase change material cavity (31).

2. The lithium battery current-conducting structure according to claim 1, characterized in that: The metal conductive layer (21) is made of 6061 aluminum alloy, which ensures good electrical conductivity while having high mechanical strength.

3. The lithium battery current-conducting structure according to claim 2, characterized in that: The array-type flow-guiding microchannels (211) are arranged in a hexagonal honeycomb pattern, with the ratio of channel depth to channel width controlled between 1:1.5 and 1:2.5, and the spacing between adjacent microchannels is 1.2 to 1.8 times the channel width.

4. The lithium battery current-conducting structure according to claim 3, characterized in that: The insulating spacer layer (22) comprises a polyimide composite material reinforced with nano-alumina.

5. A lithium battery current-conducting structure according to claim 4, characterized in that: The phase change material cavity (31) is filled with paraffin / expanded graphite composite phase change material, the phase change temperature is set at 45±2℃, and the latent heat value is ≥180J / g.

6. The lithium battery current-conducting structure according to claim 5, characterized in that: The heat conduction fins (32) are made of copper / graphene composite foil with a thickness of 0.1-0.3 mm and have a micron-level dendritic fractal structure on the surface.

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