CN219716978U - Lithium battery and battery device - Google Patents

Abstract

The present utility model relates to a lithium battery and a battery device, the lithium battery includes: a core pack assembly; the heat pipe is arranged in the core pack assembly; and at least one fin, located at one side of the core pack assembly, connected to the heat pipe and extending outwards along the radial direction of the heat pipe, wherein at least one fin comprises a hollow cavity extending along the radial direction, and the surface of the fin is provided with a plurality of hollow holes communicated with the cavity. By arranging the heat pipe in the lithium battery core pack assembly and arranging at least one fin on one side of the core pack assembly, the heat pipe can be used for accelerating heat transfer in the core pack assembly, so that the risk of heat concentration in the core pack assembly is reduced, the heat dissipation efficiency of the lithium battery is further improved, the internal temperature and the external temperature of the lithium battery are further balanced, the lithium battery is kept in a reasonable temperature range during working, the influence of heat concentration on the performance of the lithium battery is reduced, and in addition, the heat pipe and the fin are simple and convenient in structural arrangement, and the maintenance difficulty of the lithium battery is reduced.

Description

Lithium battery and battery device

Technical Field

The utility model relates to the technical field of batteries, in particular to a lithium battery and a battery device.

Background

In recent years, the urgent demands for Electric Vehicles (EV) and battery energy storage stations (Battery Energy Storage System, BESS) are continuously increasing around the world. Among many energy storage technologies, lithium batteries are popular and dominant storage media with the advantages of high efficiency, low self-discharge rate, no memory effect, long cycle life and the like, and are widely applied to electric automobiles and battery energy storage stations.

During the charge and discharge process of the lithium battery, a great amount of heat is generated due to the internal electrochemical reaction and the internal impedance. If a large amount of heat generated inside the lithium battery is not effectively exchanged, the temperature of the lithium battery is gradually increased. When the temperature of the lithium battery exceeds a certain temperature range, the working performance of the lithium battery can be affected, and serious dangerous consequences such as burning or explosion of the lithium battery can be caused. In practical application, in order to meet the more popular application demands of electric automobiles, a lithium battery must realize rapid charge and discharge performance, and operate with high power in a short time, so that a large amount of heat is rapidly generated inside the lithium battery. Therefore, in order to ensure that the electric automobile can normally operate within a reasonable safety temperature range, it is very important to solve the problem of thermal safety of the lithium battery.

However, since the heat dissipation effect of the lithium battery is limited, heat transfer must be accelerated by means of some external cooling modes, so that the lithium battery can be kept within a reasonable temperature range in the working process, the influence on the performance of the lithium battery is reduced, and safety accidents are avoided. Some cooling methods exist at present, and although the technology is relatively mature, many defects still exist. For example, in the conventional gas cooling method, the air flow formed in the running process of the electric automobile is directly utilized to dissipate heat of the lithium battery pack, and the method is low in cost and easy to implement, but the temperature difference between the inside and the outside of the lithium battery is large, and the performance of the lithium battery is affected by poor temperature uniformity. For another example, although liquid cooling can achieve higher cooling efficiency, the whole cooling system needs to be provided with a liquid cooling pipeline, so that the structure is complex and maintenance is difficult. Therefore, there is a need to develop a simpler and more efficient lithium battery heat dissipation scheme.

Disclosure of Invention

In view of this, the utility model provides a lithium battery and a battery device, which can utilize a heat pipe to accelerate heat transfer inside a core pack assembly, reduce the risk of heat concentration inside the core pack assembly, further improve the heat dissipation efficiency of the lithium battery, further balance the internal and external temperatures of the lithium battery, keep the lithium battery in a reasonable temperature range during operation, reduce the influence of heat concentration on the performance of the lithium battery, and in addition, the heat pipe and the fin have simple and convenient structural arrangement, thereby reducing the maintenance difficulty of the lithium battery.

In a first aspect, an embodiment of the present utility model provides a lithium battery including: a core pack assembly; the heat pipe is arranged in the core pack assembly; and at least one fin, located at one side of the core pack assembly, connected to the heat pipe and extending outwards along the radial direction of the heat pipe, wherein at least one fin comprises a hollow cavity extending along the radial direction, and the surface of the fin is provided with a plurality of hollow holes communicated with the cavity.

In an embodiment, the core pack assembly comprises two core packs and a heat conducting sheet positioned between the two core packs, and the heat pipe is clamped to the heat conducting sheet.

In an embodiment, the heat pipe includes a first sub-pipe and a second sub-pipe, the first sub-pipe is sleeved outside the second sub-pipe and is clamped to the heat conducting fin, and the second sub-pipe extends out of the core package assembly and is connected to at least one fin.

In an embodiment, a bayonet extending along the axial direction of the first sub-tube is arranged at one end of the first sub-tube far away from the fin, and the heat conducting fin extends into the bayonet.

In an embodiment, the surface of the fin is provided with a socket hole for the second sub-tube to pass through.

In an embodiment, the number of the fins is a plurality, the fins are parallel to each other, and the distance between every two adjacent fins is equal.

In one embodiment, the fins are of a cylindrical-like structure.

In an embodiment, the plurality of hollowed holes of each fin are uniformly distributed.

In an embodiment, each of the hollow holes is honeycomb-shaped.

In a second aspect, an embodiment of the present utility model provides a battery device, where the battery device includes a heat source and the lithium battery, the heat source is connected to a heat pipe of the lithium battery, and the heat source is used to heat the heat pipe in a low-temperature environment.

By arranging the heat pipe in the lithium battery core pack assembly, the heat transfer in the core pack assembly can be quickened by utilizing the heat pipe according to aspects of the utility model, the risk of heat concentration in the core pack assembly is reduced, and the heat dissipation efficiency of the lithium battery is further improved; the heat pipe and the fins are simple and convenient in structural arrangement, and the maintenance difficulty of the lithium battery is reduced.

Drawings

The technical solution and other advantageous effects of the present utility model will be made apparent by the following detailed description of the specific embodiments of the present utility model with reference to the accompanying drawings.

Fig. 1 shows a front view of a lithium battery according to an embodiment of the present utility model.

Fig. 2 shows a perspective view of a lithium battery according to an embodiment of the present utility model.

FIG. 3 illustrates a front view of a heat pipe and fins of an embodiment of the present utility model.

Fig. 4 shows a perspective view of a fin according to an embodiment of the present utility model.

Detailed Description

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. It will be apparent that the described embodiments are only some, but not all, embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to fall within the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements or interaction relationship between the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The following disclosure provides many different embodiments, or examples, for implementing different features of the utility model. In order to simplify the present disclosure, components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. Furthermore, the present utility model may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present utility model provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials. In some instances, well known methods, procedures, components, and circuits have not been described in detail so as not to obscure the present utility model.

Fig. 1 shows a front view of a lithium battery according to an embodiment of the present utility model. As shown in fig. 1, the lithium battery may include a core pack assembly 1, a heat pipe 2, and at least one fin 3. Wherein the core pack assembly 1 may include at least two core packs, each of which may be provided therein with a separator, such as a positive electrode sheet, a negative electrode sheet, and the like. A gap may be left between every two core packs, and the interior of the gap is the interior of the core pack assembly 1. The heat pipe 2 may be provided inside the core pack assembly 1. Illustratively, the core pack assembly 1 is of a rectangular parallelepiped configuration. A housing 10 may also be provided around the core pack assembly 1, and the core pack assembly 1 may be placed in the housing 10.

In an embodiment, the at least one fin 3 may be located on one side of the core pack assembly 1. For example, referring to fig. 1, a fin 3 may be provided on the upper side of the core pack assembly 1. The at least one fin 3 may be connected to the heat pipe 2 and extend outward in a radial direction of the heat pipe 2, and the radial direction of the heat pipe 2 may be a horizontal direction in fig. 1. The fins 3 may extend leftward in the radial direction of the heat pipe 2 or rightward in the radial direction of the heat pipe 2.

In the present utility model, the heat pipe is a heat conductive member, has excellent heat conductivity, and can maintain good isothermicity. Because the internal central area of the lithium battery has smaller functionality, the arrangement of the heat pipe has smaller influence on the performance of the lithium battery. When the temperature of the battery is overhigh, the temperature of the central area of the lithium battery is highest, so that the heat pipe positioned in the central area of the lithium battery can rapidly guide out heat to other parts of the battery, thermal runaway caused by heat concentration is avoided, and the internal temperature of the lithium battery is controlled within a reasonable range.

In an embodiment, referring to fig. 1, at least one of the fins 3 includes a hollow cavity 31 extending along the radial direction, and a surface of the fin is provided with a plurality of hollow holes 32 communicating with the cavity. The number of the fins 3 and the number of the hollow holes 32 may be set according to actual needs, which is not limited in the present utility model.

By arranging the heat pipe in the lithium battery core pack assembly, the heat pipe can be utilized to accelerate heat transfer in the core pack assembly, so that the risk of heat concentration in the core pack assembly is reduced, and the heat dissipation efficiency of the lithium battery is further improved; the embodiment of the utility model can further balance the internal temperature and the external temperature of the lithium battery, ensure that the lithium battery is kept in a reasonable temperature range during working, reduce the influence of heat concentration on the performance of the lithium battery, and in addition, the heat pipe and the fins are simple and convenient in structural arrangement, and reduce the maintenance difficulty of the lithium battery.

Fig. 2 shows a perspective view of a lithium battery according to an embodiment of the present utility model. Referring to fig. 2, the core-pack assembly 1 may include two core packs, wherein the positive electrode tab 11 of one core pack may be connected to the positive electrode terminal 101 of the core pack, and the negative electrode tab 13 of the other core pack may be connected to the negative electrode terminal 102 of the core pack. For example, a negative electrode plate adapted to the positive electrode plate 11 may be further disposed at the position of the positive electrode plate 11, and a positive electrode plate adapted to the negative electrode plate 13 may be further disposed at the position of the negative electrode plate 12. In practical applications, the internal structure of each core pack of the core pack assembly 1 may be adjusted according to needs, which is not limited in the present utility model.

Further, the core pack assembly 1 may further include a heat conducting sheet 12 located between the two core packs, and the heat pipe 2 may be clamped to the heat conducting sheet 12. The heat conducting fins 12 are respectively attached to the outer surfaces of two adjacent core packages, so that heat of the two core packages can be transferred to the heat pipe 2 through the heat conducting fins 12. The thermally conductive sheet 12 may be a nickel foil, for example. The nickel foil has good electrical conductivity and thermal conductivity, mature manufacturing technology and relatively low price. By clamping the heat pipe to the heat conducting fin, the embodiment of the utility model can play a role in fixedly supporting the heat pipe by using the heat conducting fin, and simultaneously, the heat conduction efficiency is improved by using the sheet-shaped structure of the heat conducting fin.

Referring to fig. 2, the heat pipe 2 may include a first sub-pipe 21 and a second sub-pipe 22, the first sub-pipe 21 and the second sub-pipe 22 are defined by a junction between the heat pipe 2 and the core pack assembly 1, and a heat pipe located below the junction may be referred to as the first sub-pipe 21, and a heat pipe located above the junction may be referred to as the second sub-pipe 22. The first sub-tube 21 is used for converging heat in the battery, and the second sub-tube 22 is used for rapidly guiding out the heat, and the two sub-tubes are connected and act together.

Further, the first sub-tube 21 is sleeved outside the second sub-tube 22 and is clamped to the heat conducting fin 12, and the second sub-tube 22 extends out of the core pack assembly 1 and is connected to at least one fin 3. The first sub-tube 21 and the second sub-tube 22 may have a flat hollow structure, and the diameter of the first sub-tube 21 may be the same as or different from the diameter of the second sub-tube 22. Preferably, the diameter of the first sub-pipe 21 is smaller than 2mm to better collect heat inside the core-bag assembly 1; the diameter of the second sub-pipe 22 is smaller than 6mm so as to quickly conduct the heat inside the core-envelope assembly 1 to the outside of the core-envelope assembly 1.

In an embodiment, a bayonet 211 extending along the axial direction of the first sub-tube is provided at an end of the first sub-tube 21 away from the fin 3, and the heat conductive sheet 12 extends into the bayonet 211. The first sub-tube 21 can be firmly connected to the heat conductive sheet 12 by the bayonet 211. In fig. 2, the axial direction of the first sub-pipe 21 is the vertical direction. The length of the first sub-tube 21 is smaller than the width of the heat conductive sheet 12 in the axial direction of the first sub-tube 21. Illustratively, the bayonet 211 may be an arched door structure.

FIG. 3 illustrates a front view of a heat pipe and fins of an embodiment of the present utility model. Referring to fig. 3, the surface of the fin 3 may be provided with a socket hole 33 for the second sub-tube 22 to pass through. The number of the socket holes 33 of the fin 3 may be one or a plurality of. For example, in fig. 3, the number of the socket holes 33 of the fin at the tip may be provided with one, and the number of the socket holes 33 of the other fin in fig. 3 may be provided with two. For another example, when the number of the second sub-tubes 22 of fig. 3 is increased to two, the number of the fin holes 33 of the fins of the top cover may be provided with two.

Wherein, the socket hole 33 may be configured as a spherical protrusion or a spherical depression, so that the fin 3 is tightly socket-connected with the second sub-tube 22. The specific size of the socket hole 33 may be adaptively adjusted according to the diameter of the second sub-pipe 22, which is not limited in the present utility model.

In an embodiment, as shown in fig. 3, the number of the fins 3 may be plural, and plural fins 3 are parallel to each other, and the intervals between every two adjacent fins 3 are equal. By arranging the fins which are uniformly distributed, heat conduction outside the core-in-package assembly can be further balanced. In practical applications, the degree of the density of the fins 3 along the axial direction of the second sub-tube 22 may be adjusted as required. For example, if the heat concentration phenomenon of the second sub-tube 22 near the end of the first sub-tube 21 is more obvious than the heat concentration phenomenon of the second sub-tube 22 far from the end of the first sub-tube 21, a first fin assembly may be disposed at the end of the second sub-tube 22 near the first sub-tube 21, a second fin assembly may be disposed at the end of the second sub-tube 22 far from the first sub-tube 21, and the interval between every two adjacent fins in the first fin assembly is smaller than the interval between every two adjacent fins in the second fin assembly, that is, the arrangement of a plurality of fins presents a characteristic from sparse to dense along the axial direction of the second sub-tube 22 toward the first sub-tube 21.

Fig. 4 shows a perspective view of a fin according to an embodiment of the present utility model. Referring to fig. 4, the fin 3 may have a cylindrical-like structure, and the arrangement of the cylindrical-like structure can facilitate the production of the fin and reduce the generation of scraps. The cylindrical-like structure may be a combination of a cylindrical structure with the hollowed-out hole and the socket hole. It will be appreciated that the fins may also be provided in other similar configurations, for example, the ends of the fins may be oval.

Further, the plurality of hollowed-out holes 32 of each fin 3 are uniformly distributed. Through set up evenly distributed's fretwork hole 32 along the axial of fin 3, can further even heat at the conduction of fin 3, and then further even the inside and outside temperature of lithium cell, make the lithium cell during operation keep at reasonable temperature range, reduce the influence that heat concentrated to the lithium cell performance.

In an embodiment, the plurality of hollowed holes 32 of each fin 3 may be unevenly distributed along the axial direction of the fin 3. That is, the degree of the density of the hollowed-out holes 32 along the axial direction of the fin 3 can be adjusted according to the requirement. For example, if the heat concentration phenomenon at the junction of the fin 3 and the heat pipe 2 is more obvious than the heat concentration phenomenon at the junction of the fin 3 and the two ends of the heat pipe 2, a first hollow component may be disposed at the junction of the fin 3 and the heat pipe 2, a second hollow component may be disposed at the junction of the fin 3 and the two ends of the heat pipe 2, and the distance between every two adjacent hollow holes in the first hollow component is smaller than the distance between every two adjacent hollow holes in the second hollow component, that is, the arrangement of the hollow holes presents a dense-to-sparse characteristic from the middle to the two ends along the axial direction of the fin 3. Or the area of each hollow hole in the first hollow component is smaller than that of each hollow hole in the second hollow component.

Further, each of the hollow holes 32 is honeycomb-shaped. Because the fin is honeycomb network structure, possess very big radiating area, be connected with the heat pipe, can be with the heat pipe from the inside heat dissipation of deriving of battery fast to reach the effect that effectively reduces lithium cell temperature, promote battery safety. Illustratively, in fig. 4, the hollowed-out hole 32 may be a regular hexagon. The hollowed-out hole 32 may be provided in other shapes, such as regular octagon. Each hollowed-out hole 32 is arranged in a honeycomb shape, so that the stability of the frame of the fin 3 is facilitated, and the material abrasion phenomenon caused by unreasonable hollowed-out hole arrangement is reduced. It should be noted that, in fig. 4, the hollowed-out holes 32 do not extend to the edges 34 of the fins 3, i.e. the edges of the two ends of the fins 3 are not provided with hollowed-out holes, so that the heat conduction of the tail ends of the fins 3 can be enhanced, and the structural wear of the tail ends of the fins 3 can be reduced.

In an embodiment, the fins 3 may be made of copper, and the inner surfaces of the fins 3 are coated with a phase change material to form a phase change material layer. For example, the copper tubing can be made using copper foam. The foam copper material has higher heat conductivity and can play a role in enhancing heat transfer. The phase-change material has small temperature change, can play a role in heat buffering, and can effectively solve the problem of low heat conductivity of the traditional phase-change material by combining the foam copper fins and the phase-change material.

In summary, the heat pipe is arranged in the lithium battery core pack assembly, so that the heat transfer in the core pack assembly can be quickened by using the heat pipe, the risk of heat concentration in the core pack assembly is reduced, and the heat dissipation efficiency of the lithium battery is further improved; the embodiment of the utility model can further balance the internal temperature and the external temperature of the lithium battery, ensure that the lithium battery is kept in a reasonable temperature range during working, reduce the influence of heat concentration on the performance of the lithium battery, and in addition, the heat pipe and the fins are simple and convenient in structural arrangement, and reduce the maintenance difficulty of the lithium battery.

In addition, the utility model also provides a battery device, which comprises a heat source and the lithium battery, wherein the heat source is connected with the heat pipe 2 of the lithium battery, and is used for heating the heat pipe 2 in a low-temperature environment.

For example, a lithium battery may develop a charging lithium precipitation phenomenon under a low temperature condition. This is because the lithium intercalation resistance of the negative electrode at low temperature is significantly higher than the lithium deintercalation resistance of the positive electrode, and although lithium ions can be relatively rapidly deintercalated from the positive electrode at low temperature, they cannot be timely intercalated into the negative electrode, thereby causing lithium precipitation. The lithium precipitation not only reduces the battery performance and shortens the cycle life greatly, but also limits the quick charge capacity of the battery, and can cause disastrous consequences such as combustion, explosion and the like.

Therefore, in the utility model, the heat is quickly transferred into the battery through the fin-heat pipe structure by heating the fin under the low-temperature condition, and the heat pipe 2 positioned in the central area of the lithium battery transfers the heat to all parts of the battery, so that the temperature in the battery is controlled within a reasonable range, and the purpose of quickly heating the battery is achieved. By heating the heat pipe 2, lithium precipitation of the lithium battery and puncture of the diaphragm can be prevented during charging. Meanwhile, from the perspective of discharging, the lithium battery is kept in a reasonable working temperature range by heating the heat pipe 2 under the low temperature condition, and the discharging capability of the lithium battery is also improved. When the temperature of the battery is too low and the charging working condition is not supported, the heat pipe 2 can be heated outside the battery through the heat source, so that the temperature rising and heat collecting functions are realized, and the charging working condition of the battery is achieved.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

The above describes the lithium battery and the battery device provided by the embodiment of the present utility model in detail, and specific examples are applied to illustrate the principle and the implementation of the present utility model, and the description of the above embodiments is only used to help understand the technical solution and the core idea of the present utility model; those of ordinary skill in the art will appreciate that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (11)

1. A lithium battery, the lithium battery comprising:

a core pack assembly (1);

the heat pipe (2) is arranged in the core pack assembly (1); and

at least one fin (3) is located one side of the core-wrap assembly (1), is connected to the heat pipe (2) and extends outwards along the radial direction of the heat pipe (2), at least one fin (3) comprises a hollow cavity (31) extending along the radial direction, and a plurality of hollowed-out holes (32) communicated with the cavity (31) are formed in the surface of the fin (3).

2. The lithium battery according to claim 1, wherein the core pack assembly (1) comprises two core packs and a heat conducting sheet (12) positioned between the two core packs, and the heat pipe (2) is clamped to the heat conducting sheet (12).

3. The lithium battery according to claim 2, wherein the heat pipe (2) comprises a first sub-pipe (21) and a second sub-pipe (22), the first sub-pipe (21) is sleeved outside the second sub-pipe (22) and is clamped to the heat conducting fin (12), and the second sub-pipe (22) extends out of the core pack assembly (1) and is connected to at least one fin (3).

4. A lithium battery according to claim 3, characterized in that the end of the first sub-tube (21) remote from the fins (3) is provided with a bayonet (211) extending in the axial direction of the first sub-tube (21), the thermally conductive sheet (12) extending into the bayonet (211).

5. A lithium battery according to claim 3, characterized in that the surface of the fin (3) is provided with a socket hole (33) for the second sub-tube (22) to pass through.

6. A lithium battery according to any one of claims 3-5, characterized in that the number of the fins (3) is plural, the fins (3) are parallel to each other, and the interval between every two adjacent fins (3) is equal, or the fins (3) are arranged from sparse to dense along the axial direction of the second sub-tube (22) toward the first sub-tube (21).

7. A lithium battery according to any of claims 1-5, characterized in that the fins (3) are of a cylindrical-like structure.

8. Lithium battery according to any one of claims 1-5, characterized in that the plurality of hollowed-out holes (32) of each fin (3) are evenly distributed.

9. The lithium battery according to any one of claims 1-5, wherein each of the hollowed-out holes (32) is honeycomb-shaped.

10. A lithium battery according to any of claims 1-5, characterized in that the inner surface of the fins (3) is coated with a phase change material.

11. A battery device, characterized in that it comprises a heat source and a lithium battery according to any one of claims 1-10, said heat source being connected to a heat pipe (2) of said lithium battery, said heat source being adapted to heat said heat pipe (2) in a low temperature environment.