Short-knife battery, preparation method, battery module and power utilization device

Abstract

The invention provides a short-knife battery, a preparation method, a battery module and a power utilization device. The short-knife battery comprises a shell, a battery cell and a heat conduction structure, the shell is provided with a containing cavity, and electrolyte is injected into the containing cavity. And the battery cell is arranged in the accommodating cavity and is soaked in the electrolyte. And the heat conduction structure is sleeved on the battery cell. The heat conduction structure comprises a first face and a second face which are oppositely arranged. The first surface is connected to the battery cell, and the second surface abuts against the inner wall. The heat conduction coefficient of the heat conduction structure is larger than or equal to that of the electrolyte. In the related technology, the heat generated by the battery cell is transferred to the aluminum shell through the electrolyte in the accommodating cavity for heat dissipation. On the basis, the heat generated by the battery cell of the short-knife battery is transferred to the shell through the heat conduction structure for heat dissipation, so that the speed of heat transfer between the battery cell and the shell is increased, the heat dissipation speed of the battery cell is further increased, the probability of thermal runaway of the battery is reduced, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a short-blade battery, a preparation method, a battery module and an electrical device. Background Art

[0002] The short-blade battery is a type of lithium-ion battery. Compared with the traditional square battery, the short-blade battery can greatly improve the space utilization and energy density of the battery pack, reduce the internal resistance, and facilitate the heat preservation and heat dissipation of the battery. The short-blade battery may include a shell and a battery cell. The shell has a receiving cavity, and the battery cell is arranged in the above-mentioned receiving cavity.

[0003] During the charging and discharging process of the battery, a large amount of heat is generated at both ends of the battery cell. In the related art, the heat generated by the battery cell is transferred to the aluminum shell through the electrolyte in the accommodating cavity for heat dissipation, but the heat dissipation effect is not ideal, so that the probability of thermal runaway is high. Summary of the invention

[0004] The present application provides a short knife battery, a preparation method, a battery module and an electrical device to solve the problem of high probability of thermal runaway of the battery, improve the heat dissipation efficiency of the battery, reduce the probability of thermal runaway of the battery, and thus extend the service life of the battery.

[0005] In a first aspect, the present application provides a short knife battery, comprising: a shell, a battery cell and a heat-conducting structure. The shell has a accommodating cavity, and the accommodating cavity is filled with an electrolyte. The battery cell is arranged in the accommodating cavity and immersed in the electrolyte. The heat-conducting structure is sleeved on the battery cell. The heat-conducting structure includes a first surface and a second surface arranged opposite to each other. The first surface is connected to the battery cell, and the second surface abuts against the inner wall of the shell. The thermal conductivity of the heat-conducting structure is greater than or equal to the thermal conductivity of the electrolyte.

[0006] According to the first aspect, in the related art, the heat generated by the battery cell is transferred to the aluminum shell through the electrolyte in the accommodating cavity for heat dissipation. Based on this, the heat generated by the battery cell of the short knife battery in the present application is transferred to the shell through the heat conduction structure for heat dissipation, and the thermal conductivity of the heat conduction structure is greater than or equal to the thermal conductivity of the electrolyte, thereby increasing the speed of heat transfer between the battery cell and the shell, thereby increasing the heat dissipation speed of the battery cell, reducing the probability of thermal runaway of the battery, and extending the service life of the battery.

[0007] In a possible design, two heat-conducting structures are provided on the battery core, and the two heat-conducting structures are respectively provided at two ends of the battery core along the length direction of the battery core.

[0008] Based on the description of the above embodiment, two heat-conducting structures are arranged at both ends of the battery cell along the length direction of the battery cell to increase the heat dissipation speed at the position where the short knife battery is prone to thermal runaway, thereby reducing the probability of thermal runaway of the battery and extending the service life of the battery.

[0009] In a possible design, the heat-conducting structure is an integrated structure.

[0010] Based on the description of the above embodiments, the heat-conducting structure is an integrated structure, so that the heat-conducting structure has good mechanical properties and high connection strength. At the same time, the assembly process of the heat-conducting structure and the battery core is simplified, the production efficiency is improved and the production cost is reduced.

[0011] In a possible design, the material of the heat conducting structure is elastic.

[0012] Based on the description of the above embodiments, when the heat-conducting structure is an integrated structure, the heat-conducting structure is elastic, so that the heat-conducting structure can be smoothly mounted on the battery cell, while also making the position between the heat-conducting structure and the battery cell relatively fixed, thereby ensuring stable and effective contact between the heat-conducting structure and the battery cell.

[0013] In a possible design, the elastic material is a CP-200 thermally conductive silicone sheet.

[0014] Based on the description of the above embodiments, the CP-200 thermally conductive silicone sheet has a high thermal conductivity and is elastic, which can enable the thermal conductive structure to be smoothly mounted on the battery cell while also making the position between the thermal conductive structure and the battery cell relatively fixed.

[0015] In a possible design, the heat-conducting structure includes a first part and a second part. The first part and the second part are buckled to form an installation space. The battery cell is arranged in the installation space.

[0016] Based on the description of the above embodiment, the heat-conducting structure includes a first part and a second part. The battery cell is arranged in an installation space formed by the first part and the second part being buckled. The buckled assembly method is easy to operate and easier to implement, which is conducive to simplifying the assembly process and reducing production costs.

[0017] In a possible design, the first part and the second part are detachably connected. Alternatively, the first part and the second part are fixedly connected.

[0018] Based on the description of the above embodiments, the detachable connection has advantages such as high maintenance efficiency, etc. The fixed connection has advantages such as high stability and good fatigue resistance, etc. The operator can select the connection method between the first part and the second part according to actual needs.

[0019] In a second aspect, the present application provides a method for preparing a short knife battery, which is used to prepare the short knife battery described in any one of the above embodiments, and the method comprises:

[0020] Get the battery cell;

[0021] Acquire a heat-conducting structure, wherein the heat conductivity of the heat-conducting structure is greater than the heat conductivity of the electrolyte;

[0022] Sleeve the heat-conducting structure on the battery core so that the first surface of the heat-conducting structure abuts against the battery core;

[0023] Obtaining a housing having a receiving cavity;

[0024] injecting the electrolyte into the containing cavity;

[0025] The battery cell is placed in the accommodation cavity and immersed in the electrolyte, and the second surface of the heat-conducting structure is abutted against the inner wall of the shell, wherein the first surface and the second surface are two surfaces arranged opposite to each other.

[0026] In a third aspect, the present application provides a battery module, comprising the short blade battery described in any one of the above embodiments, wherein one or more short blade batteries are arranged in the battery module.

[0027] In a fourth aspect, the present application provides an electrical device, comprising the battery module described in the above embodiment, and the battery module is used to provide electrical energy.

[0028] The beneficial effects of the preparation method provided in the second aspect, the battery module provided in the third aspect, and the electrical device provided in the fourth aspect can be referred to the beneficial effects brought about by the first aspect and the possible implementation methods of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic diagram of the structure of a short knife battery provided in an embodiment of the present application.

[0031] Figure 2 A schematic structural diagram of a heat-conducting structure provided in an embodiment of the present application.

[0032] Figure 3 for Figure 1 Cross-sectional view along direction A.

[0033] Figure 4 for Figure 3 Magnified view of section B.

[0034] Figure 5 for Figure 1 Views in other directions.

[0035] Description of reference numerals:

[0036] 100, short knife battery;

[0037] 1. Shell;

[0038] 2. Battery cells;

[0039] 3. Heat-conducting structure; 31. First surface; 32. Second surface; 3a. First part; 3b. Second part. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] The terms "comprising" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover but not exclude other contents. The word "a" or "an" does not exclude the presence of a plurality.

[0043] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0044] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0045] The directional words appearing in the following description are all directions shown in the drawings, and do not limit the specific structure of the present application. For example, in the description of the present application, the directions or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application.

[0046] In addition, the expressions of indicated directions such as the X direction, the Y direction, and the Z direction used to illustrate the operation and construction of the components of the present embodiment are not absolute but relative, and although these indications are appropriate when the components are in the positions shown in the figures, when these positions are changed, these directions should be interpreted differently to correspond to the changes.

[0047] In addition, the terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0048] In the description of the present application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two groups (including two).

[0049] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, the "connection" or "connection" of a mechanical structure may refer to a physical connection. For example, the physical connection may be a fixed connection, such as a fixed connection through a fixing member, such as a fixed connection through a screw, bolt or other fixing member; the physical connection may also be a detachable connection, such as a mutual snap connection or snap connection; the physical connection may also be an integral connection, such as welding, bonding or integral molding to form a connection for connection. The "connection" or "connection" of a circuit structure may refer to an electrical connection or a signal connection in addition to a physical connection. For example, it may be a direct connection, that is, a physical connection, or it may be an indirect connection through at least one intermediate element, as long as the circuit is connected, or it may be the internal connection of two elements; the signal connection may refer to a signal connection through a media medium, such as a radio wave, in addition to a signal connection through a circuit. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] An electrical device refers to an electrical device that uses electrical energy to perform specific functions. Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc. The above devices provide various functions or services by connecting to a power supply.

[0051] A battery module, also known as a battery pack or battery array, is a whole composed of multiple battery cells (such as lithium-ion battery cells) connected in series and / or in parallel in a specific way. This whole is designed to provide higher voltage and larger capacity to meet the needs of various applications, such as electric vehicles, energy storage systems, drones, etc.

[0052] A battery is the basic unit that makes up a battery module, usually a chemical device that can generate electrical energy. In a battery module, multiple battery cells are connected in series or in parallel to form the required voltage and current. For example, our common AA battery is a single cell, which contains chemical substances that can convert chemical energy into electrical energy.

[0053] The short-blade battery is a type of lithium-ion battery. Compared with the traditional square battery, the short-blade battery can greatly improve the space utilization and energy density of the battery pack, reduce the internal resistance, and facilitate the heat preservation and heat dissipation of the battery. The short-blade battery may include a shell and a battery cell. The shell has a receiving cavity, and the battery cell is arranged in the above-mentioned receiving cavity.

[0054] During the charging and discharging process of the battery, a large amount of heat is generated at both ends of the battery cell. In the related art, the heat generated by the battery cell is transferred to the aluminum shell through the electrolyte in the accommodating cavity for heat dissipation, but the heat dissipation effect is not ideal and thermal runaway is likely to occur.

[0055] Based on this, the present application provides a short knife battery, which improves the heat dissipation efficiency by arranging a heat-conducting structure in the accommodating cavity, thereby reducing the probability of thermal runaway of the battery and extending the service life of the battery. Figure 1-Figure 5 Provide detailed explanation.

[0056] First, as Figure 1 and Figure 2 As shown, the present application provides a short knife battery 100, including: a shell 1, a battery cell 2 and a heat-conducting structure 3. The shell 1 has a accommodating cavity, and the accommodating cavity is filled with an electrolyte (not shown in the figure). The battery cell 2 is arranged in the accommodating cavity and immersed in the electrolyte. The heat-conducting structure 3 is sleeved on the battery cell 2. The heat-conducting structure 3 includes a first surface 31 and a second surface 32 arranged opposite to each other. The first surface 31 is connected to the battery cell 2, and the second surface 32 abuts against the inner wall. The thermal conductivity of the heat-conducting structure 3 is greater than or equal to the thermal conductivity of the electrolyte.

[0057] Among them, the shell 1 has a accommodating cavity, which is used to protect the chemical substances inside the short knife battery 100, provide structural strength, prevent physical damage to the short knife battery 100, and prevent battery short circuit and electrolyte leakage. In addition, the shell 1 can also be used for heat dissipation of the short knife battery 100 to ensure that the short knife battery 100 operates within a safe temperature range. Specifically, the shell 1 may include an inner wall and an outer wall. The inner wall faces the inside of the accommodating cavity and is used to conduct heat inside the accommodating cavity. The outer wall faces the external environment and is used to exchange heat with the external environment, thereby achieving the purpose of heat dissipation. Specifically, the shell 1 can be an aluminum shell, which has a higher heat conduction efficiency.

[0058] Among them, the battery cell 2 is arranged in the accommodating cavity. And the battery cell 2 can participate in the charging and discharging reaction of the short knife battery 100. Among them, the charging and discharging process of the short knife battery 100 is usually accompanied by the release of energy, which causes the battery cell 2 to generate higher heat, and then easily causes thermal runaway. Among them, thermal runaway refers to the rapid rise in temperature of the short knife battery 100, which may cause fire or explosion. Thermal runaway is usually triggered by reasons such as internal short circuit of the short knife battery 100, overcharging, over-discharging, external heat source, electrolyte decomposition or failure of the battery management system. During the thermal runaway process, the heat generation rate inside the short knife battery 100 exceeds its heat dissipation capacity, resulting in a continuous increase in temperature, which may eventually cause structural damage to the short knife battery 100, and even trigger a chain reaction, affecting the safety of the entire battery.

[0059] Specifically, the accommodating cavity is filled with electrolyte, the battery core 2 is immersed in the electrolyte, and a charge-discharge reaction occurs with the electrolyte. Therefore, there is a gap between the surface of the battery core 2 and the inner wall of the housing 1. The above gap is used to store the electrolyte.

[0060] Specifically, the electrolyte may include ingredients such as an organic solvent, an electrolyte lithium salt, and an additive. Among them, the organic solvent may be ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), or ethyl methyl carbonate (EMC), etc. The organic solvent is used to dissolve the electrolyte lithium salt and provide a carrier for ion transport. Among them, ethylene carbonate (EC) is a commonly used organic solvent in related technologies. The thermal conductivity of ethylene carbonate is about 0.14W / (m·K).

[0061] The electrolyte lithium salt may be lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4) or lithium pentafluoroarsenate (LiAsF6), among which lithium hexafluorophosphate (LiPF6) is a commonly used electrolyte lithium salt in the related art. The thermal conductivity of lithium hexafluorophosphate (LiPF6) is about 0.2W / (m·K).

[0062] The additives may include membrane additives, conductive additives, flame retardant additives or overcharge protection additives, etc. The additives are used to improve the performance of the electrolyte and increase the safety and cycle life of the short knife battery 100.

[0063] Furthermore, the above-mentioned interval can also be used to accommodate the heat-conducting structure 3. The heat-conducting structure 3 is arranged between the battery core 2 and the housing 1. Moreover, the heat-conducting structure 3 can be sleeved on the battery core 2.

[0064] Among them, Figure 2 As shown, the heat conducting structure 3 may include a first surface 31 and a second surface 32 that are arranged opposite to each other. Specifically, the heat conducting structure 3 may be a sleeve structure, the first surface 31 is the inner wall of the sleeve structure, and the second surface 32 is the outer wall of the sleeve structure.

[0065] Among them, Figure 3 and Figure 4 As shown, the first surface 31 is connected to the battery cell 2, so that there is effective contact between the heat-conducting structure 3 and the battery cell 2, so that the heat on the battery cell 2 can be transferred to the heat-conducting structure 3. In addition, the first surface 31 is connected to the battery cell 2, so that the heat-conducting structure 3 and the battery cell 2 are assembled as an assembly unit, which is convenient for operators to perform subsequent assembly.

[0066] Among them, Figure 3 and Figure 4 As shown, the second surface 32 abuts against the housing 1 , so that there is effective contact between the heat-conducting structure 3 and the housing 1 , so that heat can be transferred to the housing 1 through the heat-conducting structure 3 and heat dissipated through the housing 1 .

[0067] In summary, in the related art, the heat generated by the battery cell 2 is transferred to the aluminum shell 1 through the electrolyte in the accommodating cavity for heat dissipation. Based on this, the heat generated by the battery cell 2 of the short knife battery 100 in the present application is transferred to the shell 1 through the heat conducting structure 3 for heat dissipation, and the thermal conductivity of the heat conducting structure 3 is greater than or equal to the thermal conductivity of the electrolyte, thereby increasing the speed of heat transfer between the battery cell 2 and the shell 1, thereby increasing the heat dissipation speed of the battery cell 2, reducing the probability of thermal runaway of the battery, and extending the service life of the battery.

[0068] Specifically, the material of the thermal conductive structure 3 can be thermal conductive silicone cloth (Thermal Film), and the thermal conductivity of the thermal conductive silicone cloth (Thermal Film) is about 5.0W / (m·K), which is much larger than the thermal conductivity of ethylene carbonate (EC) and the thermal conductivity of lithium hexafluorophosphate (LiPF6) in the above-mentioned electrolyte. Obviously, the larger the thermal conductivity, the faster the heat transfer speed and the better the heat dissipation effect. It should be noted that the material of the thermal conductive structure 3 includes but is not limited to the above-mentioned materials, and this application does not specifically limit this.

[0069] Furthermore, one or more heat-conducting structures 3 may be provided in the short-blade battery 100 to increase the effective contact area between the heat-conducting structure 3 and the battery cell 2 and the effective contact area between the heat-conducting structure 3 and the housing 1, thereby further improving the heat dissipation speed of the short-blade battery 100. In addition, the present application does not impose any specific restrictions on the size of the heat-conducting structure 3 along the length direction of the battery cell 2. The larger the size of the heat-conducting structure 3 along the length direction of the battery cell 2, the larger the effective contact area between the heat-conducting structure 3 and the battery cell 2. Similarly, the effective contact area between the heat-conducting structure 3 and the housing 1 is also larger.

[0070] In some embodiments, Figure 5 As shown, two heat-conducting structures 3 are sleeved on the battery core 2 , and the two heat-conducting structures 3 are respectively arranged at two ends of the battery core 2 along the length direction of the battery core 2 .

[0071] The battery cell 2 may include a positive electrode tab and a negative electrode tab, and the positive electrode tab and the negative electrode tab may be arranged at both ends of the battery cell 2 along the length direction of the battery cell 2. Specifically, the positive electrode tab and the negative electrode tab may be arranged at both ends of the battery cell 2 along the length direction of the battery cell 2, respectively.

[0072] During the charging and discharging process of the short-blade battery 100, the positive and negative ears are channels for lithium ion insertion and extraction. Therefore, the heat released at the positive and negative ears is relatively high, and the probability of thermal runaway at the positive and negative ears is also high.

[0073] Based on this, the two heat-conducting structures 3 are respectively arranged at the two ends of the battery cell 2 along the length direction of the battery cell 2, that is, the two heat-conducting structures 3 are respectively arranged at the positions where the probability of thermal runaway is higher, thereby improving the heat dissipation speed at the position, reducing the probability of thermal runaway of the short knife battery 100 at the position, and extending the service life of the battery.

[0074] According to the description of the above embodiment, two heat-conducting structures 3 are arranged at both ends of the battery cell 2 along the length direction of the battery cell 2, so as to increase the heat dissipation speed at the position where the short knife battery 100 is prone to thermal runaway, thereby reducing the probability of thermal runaway of the battery and extending the service life of the battery.

[0075] Furthermore, the heat-conducting structure 3 may include the following two structural forms.

[0076] Structural form 1: The heat conducting structure 3 is an integrated structure.

[0077] Among them, the characteristics of the integrated structure may include: stability, reliability, and integrity.

[0078] According to the description of the above embodiments, the heat conducting structure 3 may be a sleeve structure, which can realize quick connection and fixation between the heat conducting structure 3 and the battery cell 2. Therefore, the sleeve structure needs to have good mechanical properties and high connection strength.

[0079] Based on this, the stability and reliability of the integrated structure are used to ensure good mechanical properties and high connection strength of the sleeve structure. In addition, the integrity of the integrated structure can simplify the assembly process of the heat conducting structure 3 and the battery core 2, and improve production efficiency.

[0080] Specifically, the integrated structure can be mass-produced by designing a universal mold and adopting a production method such as injection molding, thereby reducing the production cost of the heat-conducting structure 3.

[0081] In summary, the heat-conducting structure 3 is an integrated structure, which enables the heat-conducting structure 3 to have good mechanical properties and high connection strength. At the same time, the assembly process of the heat-conducting structure 3 and the battery cell 2 is simplified, the production efficiency is improved, and the production cost is reduced.

[0082] Furthermore, based on the first structural form, the material of the heat conducting structure 3 has elasticity.

[0083] First, since the heat-conducting structure 3 is an integrated structure and is sleeved on the battery core 2 , the inner diameter of the sleeve of the heat-conducting structure 3 needs to be greater than or equal to the outer diameter of the battery core 2 .

[0084] Secondly, after the heat-conducting structure 3 is sleeved on the battery cell 2, the position between the heat-conducting structure 3 and the battery cell 2 is relatively fixed, so as to ensure a stable and effective contact between the heat-conducting structure 3 and the battery cell 2. Based on this, the inner diameter of the sleeve of the heat-conducting structure 3 needs to be slightly smaller than the outer diameter of the battery cell 2, so that the heat-conducting structure 3 and the battery cell 2 are in interference connection.

[0085] Among them, interference connection is a specific connection method of hole-shaft connection. In the interference connection, the size of the shaft is slightly larger than the size of the hole, so external force needs to be applied during assembly to press the shaft into the hole, thereby generating an interference. The interference refers to the amount of interference between the shaft and the hole. The interference determines the tightness and load-bearing capacity of the connection. Therefore, the thermal conductive structure 3 is interference-connected with the battery cell 2, so that the thermal conductive structure 3 can press the battery cell 2, thereby achieving a relatively fixed position between the thermal conductive structure 3 and the battery cell 2.

[0086] In summary, the present application can further optimize the thermal conductive structure 3, for example, making the thermal conductive structure 3 elastic. Among them, the elasticity can make the thermal conductive structure 3 produce a recoverable deformation to compensate for the size change of the thermal conductive structure 3. Specifically, when the thermal conductive structure 3 is in the initial state, the inner diameter of the sleeve is slightly smaller than the outer diameter of the battery cell 2. In the process of sleeve-mounting the thermal conductive structure 3 and the battery cell 2, the thermal conductive structure 3 is deformed by applying an external force, so that the inner diameter of the sleeve of the thermal conductive structure 3 becomes larger, so that the thermal conductive structure 3 can be smoothly sleeved on the battery cell 2. After the thermal conductive structure 3 is sleeved on the battery cell 2, the external force is removed, and the elastic property restores the inner diameter of the sleeve of the thermal conductive structure 3 to the initial state, and the thermal conductive structure 3 presses the battery cell 2, so that the position between the thermal conductive structure 3 and the battery cell 2 is relatively fixed.

[0087] Furthermore, there are many ways to make the heat-conducting structure 3 elastic. For example, the heat-conducting structure 3 can be made of elastic material.

[0088] In summary, when the heat-conducting structure 3 is an integrated structure, the heat-conducting structure 3 is elastic, so that the heat-conducting structure 3 can be smoothly mounted on the battery cell 2, and the position between the heat-conducting structure 3 and the battery cell 2 is relatively fixed, thereby ensuring stable and effective contact between the heat-conducting structure 3 and the battery cell 2.

[0089] Specifically, the elastic material may include but is not limited to CP-200 thermal conductive silicone sheet, etc. Among them, the CP-200 thermal conductive silicone sheet has good thermal conductivity, elasticity and insulation. Specifically, the thermal conductivity of the CP-200 thermal conductive silicone sheet is 2.0W / (m·K), which is much larger than the thermal conductivity of the above-mentioned electrolyte.

[0090] Structural form 2: Figure 4 As shown, the heat conducting structure 3 may include a first portion 3a and a second portion 3b. The first portion 3a and the second portion 3b are buckled together to form an installation space. The battery cell 2 is arranged in the installation space.

[0091] A structure that is divided into two or more independent modules can be called a split structure. The heat-conducting structure 3 may include a first part 3a and a second part 3b, wherein the first part 3a is a part of the sleeve structure, and the second part 3b is another part of the sleeve structure. The first part 3a and the second part 3b are buckled to form an installation space, and the battery cell 2 is arranged in the installation space. That is, the heat-conducting structure 3 is a split structure. The first part 3a and the second part 3b may both include a first surface 31 and a second surface 32 that are arranged opposite to each other, wherein the first surface 31 abuts against the battery cell, and the second surface 32 abuts against the inner wall of the shell. Specifically, the first surface 31 of the first part 3a and the first surface 31 of the second part 3b may abut against different positions of the battery cell 2. Similarly, the second surface 32 of the first part 3a and the second surface 32 of the second part 3b may abut against different positions of the inner wall of the shell 1.

[0092] Among them, the characteristics of the split structure may include: flexibility and replaceability.

[0093] According to the description of the above embodiments, the split structure can enable the heat conducting structure 3 to be connected to the battery core 2 in a snap-fit ​​assembly manner. The snap-fit ​​assembly manner is easy to operate and easier to implement.

[0094] In summary, the heat-conducting structure 3 includes a first part 3a and a second part 3b. The battery cell 2 is arranged in an installation space formed by the first part 3a and the second part 3b being buckled. The buckled assembly method is easy to operate and easier to implement, which is conducive to simplifying the assembly process and reducing production costs.

[0095] Further, based on the second structural form, the first part 3a and the second part 3b may include the following two connection modes:

[0096] Connection method 1: The first part 3a and the second part 3b are detachably connected.

[0097] Among them, the detachable connection may have advantages such as high maintenance efficiency.

[0098] Specifically, the detachable connection may include, but is not limited to, various connection structures such as snap connection, riveting, elastic connection or quick connection.

[0099] Connection method two: the first part 3a and the second part 3b are fixedly connected.

[0100] Among them, fixed connection can have the advantages of high stability and good fatigue resistance.

[0101] Specifically, the fixed connection may include but is not limited to connection structures such as bonding.

[0102] It should be noted that the above connection structures can be used alone or in combination.

[0103] In summary, the operator can select the connection mode between the first part 3a and the second part 3b according to the actual situation. In a second aspect, the present application provides a preparation method for preparing the short knife battery described in any one of the above embodiments, the method comprising the following steps:

[0104] Step 1: Get the battery.

[0105] Step 2: Obtain a heat-conducting structure, wherein the heat-conducting structure has a thermal conductivity greater than the thermal conductivity of the electrolyte.

[0106] Step 3: Sleeve the heat-conducting structure on the battery core so that the first surface of the heat-conducting structure abuts against the battery core.

[0107] Step 4: Obtain a shell having a receiving cavity.

[0108] Step 5: injecting the electrolyte into the containing cavity.

[0109] Step 6: Place the battery cell in the receiving cavity and soak it in the electrolyte, and make the second surface of the heat-conducting structure abut against the inner wall of the shell, wherein the first surface and the second surface are two surfaces arranged opposite to each other.

[0110] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0111] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A short knife battery, characterized in that: include: Shell, battery cell and thermal conductive structure; The housing has a receiving cavity, and the receiving cavity is filled with electrolyte; The battery core is arranged in the containing cavity and immersed in the electrolyte; The heat-conducting structure is sleeved on the battery core; The heat-conducting structure comprises a first surface and a second surface which are arranged opposite to each other; The first surface is connected to the battery core, and the second surface abuts against the inner wall of the shell; The thermal conductivity of the heat-conducting structure is greater than or equal to the thermal conductivity of the electrolyte.

2. The short knife battery according to claim 1, characterized in that: The battery core is provided with two heat-conducting structures; The two heat-conducting structures are respectively arranged at two ends of the battery core along the length direction of the battery core.

3. The short knife battery according to claim 1, characterized in that: The heat-conducting structure is an integrated structure.

4. The short knife battery according to claim 3, characterized in that: The material of the heat-conducting structure is elastic.

5. The short knife battery according to claim 4, characterized in that: The material of the heat-conducting structure is CP-200 heat-conducting silicone sheet.

6. The short knife battery according to claim 1, characterized in that: The heat-conducting structure comprises a first part and a second part; The first part and the second part are buckled together to form an installation space; The battery cell is arranged in the installation space.

7. The short knife battery according to any one of claim 6, characterized in that: The first part and the second part are detachably connected; or, The first part and the second part are fixedly connected.

8. A preparation method for preparing the short blade battery according to any one of claims 1 to 7, characterized in that: The method includes: Get the battery cell; Acquire a heat-conducting structure, wherein the heat conductivity of the heat-conducting structure is greater than the heat conductivity of the electrolyte; Sleeve the heat-conducting structure on the battery core so that the first surface of the heat-conducting structure abuts against the battery core; Obtaining a housing having a receiving cavity; injecting the electrolyte into the containing cavity; The battery cell is placed in the accommodation cavity and immersed in the electrolyte, and the second surface of the heat-conducting structure is abutted against the inner wall of the shell, wherein the first surface and the second surface are two surfaces arranged opposite to each other.

9. A battery module, comprising the short blade battery according to any one of claims 1 to 7, characterized in that: One or more short knife batteries are arranged in the battery module.

10. An electrical device, comprising the battery module as claimed in claim 9, characterized in that: The battery module is used to provide electrical energy.

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