This application claims the priority of China patent application Ser. No. 202022373057.X, filed on Oct. 22, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The disclosure relates to the technical field of batteries, and especially to a battery, a battery module and a battery pack.
A rechargeable device is usually provided with rechargeable battery/batteries, such as lithium battery. To ensure the safety of the rechargeable device, on the one hand, it must be ensured that the battery is safe, for example, to avoid accidental explosions or fires caused by the battery.
Based on the above, how to design the battery and improve the safety of the battery is a technical problem to be solved urgently by those skilled in the art.
The disclosure provides a battery, a battery module, and a battery pack.
In the first aspect, an embodiment of the disclosure provides a battery. The battery includes a housing, an electrode element accommodated in the housing, a first terminal, a second terminal and a fuse structure. The electrode element includes a first electrode and a second electrode. The first terminal protrudes to an outside of the housing and is electrically connected to the first electrode. The second terminal protrudes to the outside of the housing and is electrically connected to the second electrode. The fuse structure is electrically connected to the first terminal and the housing, and the fuse structure is configured to disconnect an electrical connection between the housing and the first terminal when a current between the housing and the first terminal is greater than a preset fuse point. The fuse structure is located outside an electrical conduction path of the first terminal and the first electrode.
The second aspect of the disclosure provides a battery module including at least one battery as described above.
The third aspect, of the disclosure provides a battery pack, which includes at least one battery module as described above.
For a better understanding of the disclosure, reference may be made to exemplary embodiments shown in the following drawings. The components in the drawings are not necessarily to scale and related elements may be omitted, or in some instances proportions may have been exaggerated, so as to emphasize and clearly illustrate the features described herein. In addition, related elements or components can be variously arranged, as known in the art. Further, in the drawings, like reference numerals designate same or like parts throughout the several views.
The specific implementations of the battery, battery module and battery pack provided in the embodiments of the disclosure will be described in detail below in conjunction with the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the disclosure, rather than all the embodiments. Based on the embodiments of the disclosure, all other embodiments obtained by those of ordinary skill in the art without inventive effort shall fall within the protection scope of the disclosure.
The embodiment of the disclosure provides a battery. The structure shown in
By providing a fuse structure in the battery, the disclosure can control the housing to be insulated from the first terminal when the current between the housing and the first terminal is greater than the preset fuse point, that is, to disconnect the electrical connection between the housing and the first terminal to cut off the conductive path between the first terminal and the housing. In this way, it is possible to avoid damage to the housing due to excessive current, thereby avoiding damage to the battery and improving the safety and stability of the battery.
Moreover, by providing the fuse structure, when the current between the housing and the first terminal is not greater than the preset fuse point, the first terminal and the housing can be electrically connected, so that the housing and the first terminal have the same potential. In this way, electrochemical corrosion of the housing can be avoided, and the stability of the housing can be enhanced.
Optionally, in the embodiment of the disclosure, the fuse structure may be at least one of a wire and a fuse.
Specifically, when the fuse structure is a wire, the wire can be made of but not limited to a metal wire, such as but not limited to aluminum wire, to simplify the difficulty of making the fuse structure.
Further, in the embodiment of the disclosure, when the fuse structure is a wire, the resistance of the wire can satisfy the following relationship expression (hereinafter referred to as relationship expression 1):
Specifically, R is the resistance of the wire, c is the specific heat capacity of the wire, m is the mass of the wire, ΔT1 is the increase in temperature of the wire; K is the heat transfer coefficient of the wire, A is the heat dissipation area of the wire, and ΔT2 is the temperature difference between the wire and the heat dissipation environment, I is the current passing through the wire, and t is the fusing time required for the wire.
In addition, for the heat transfer coefficient, the heat transfer coefficient may be a positive value, and the unit may be watts/(m2·° C.), that is, W/(m2·° C.).
To be precise, optionally, the selection of the length and cross-sectional area of the wire (that is, the selection of the resistance R) can be made based on the calculation of the current (I) to form a short circuit when the insulation of the series battery in the battery module fails as well as the required fusing time (t).
Specifically, the fuse structure is disconnected when the temperature rises ΔT1 and reaches the fuse point. If the fuse structure is a wire, the above relationship expression can be determined according to the following process.
When the heat changes (indicated by Q) as the wire heats up ΔT1, then:
Specifically, Q1 represents the heat generated by the wire when it heats up ΔT1, Q2 represents the heat released by the wire, I represents the current passing through the wire, and φ represents the heat dissipation power.
Through the modification of the above expression, the relational expression 1 can be determined, and the relation between the resistance of the wire and other parameters can be determined, so that when the wire is adopted as the fuse structure, the performance parameters of the fuse structure can be controlled, so as to meet the needs of various application scenarios and improve design flexibility.
Certainly, in specific implementation, the fuse point can be set to 500 A, but not limited thereto, or set to other values according to the actual situation, as long as the safety of the battery and even the battery module can be improved through the fuse structure. The disclosure provides no limitation to the specific setting of the fuse point.
Similarly, the fusing time of the fuse structure can be set between 0.01 s and 10 s, but not limited thereto, or set to other values according to the actual situation, as long as the safety of the battery and even the battery module can be improved through the fuse structure. The disclosure provides no limitation to the specific setting of the fuse point.
In addition, optionally, in the embodiment of the disclosure, the fuse structure may also be a fuse.
That is to say, in the specific implementation, the simplest wire, or an electrical safety device (such as fuse structure, a ready-made fuse or thermal cut-off, and so on) can be adopted to realize the fuse structure to meet the needs of different application scenarios and improve the flexibility of the design.
Optionally, in the embodiment of the disclosure, the first terminal 31 is electrically connected to the first electrode 21 through the connecting member 50, as shown in the partial schematic diagram of
Alternatively, the first terminal 31 is directly electrically connected to the first electrode 21, as shown in the dashed circle al in
In other words, for the first terminal and the first electrode, the connection relationship between the two can be set in two manners. One of the connection relationship between the two is that the first terminal and the first electrode are directly connected, and there is no structure such as a connector between the two. Another connection relationship between the two is an indirect connection between the first terminal and the first electrode, that is, a connecting member is provided between the two, and the first terminal and the first electrode are connected through the connecting member.
Certainly, in actual situations, one connection configuration can be selected from the above two configuration methods according to actual needs and structural design of the battery, etc., to meet the needs of different application scenarios and improve design flexibility.
In addition, the connecting member can be made of the same material as the fuse structure, and can be made of other manufacturing materials as well, as long as the connecting member can realize electrical connection between the first terminal and the first electrode. The disclosure provides no limitation to the specific configuration method of the connecting member.
It should be noted that when the housing and the first terminal is electrically disconnected and insulated from each other, the first electrode is still electrically connected to the first terminal, and the second electrode is still electrically connected to the second terminal. That is, when the fuse structure is disconnected, it has no influence on the status of electrical connection between the first terminal and the first electrode as well as the second terminal and the second electrode. Therefore, even if the fuse structure is disconnected, it can still be ensured that the battery can work normally and effectively, such that the battery can work normally and properly while the safety and stability of the battery can be improved.
Likewise, a connection manner similar to the connection manner of the first terminal and the first electrode can also be adopted for the second terminal and the second electrode. For details, please refer to the above description, which will not be described in detail here.
Optionally, in the embodiment of the disclosure, the manufacturing material of the housing includes conductive materials. When the conductive material is metallic aluminum, the first electrode is positive, and the second electrode is negative. Alternatively, when the conductive material is an iron-based material or a copper-based material, the first electrode is negative, and the second electrode is positive.
The reason for the above configuration is as follows. The negative electrode can generally be made of carbon materials, tin-based materials, lithium-containing transition metal nitrides or alloys and other materials. The positive electrode can generally be made of lithium-containing compounds such as lithium cobaltate, lithium manganate, or lithium iron phosphate and so on. The housing can generally be made of aluminum, iron-based or copper-based materials.
During the production or use of the battery, in some cases such as internal insulation failure may cause the negative or positive electrode to be electrically connected to the housing. If the housing is made of aluminum material and the negative electrode is electrically connected to the housing, and if the potential of the housing made of aluminum material is low, lithium intercalation will occur during the process of charging and discharging or standing still and forms lithium aluminum alloy, which causes the housing made of aluminum material to corrode.
In light of the above, under the circumstances, the housing may be set to be electrically connected to the positive electrode, that is, the housing is electrically connected to the positive electrode through the first terminal, so as to prevent the housing made of aluminum material from having a low potential, thereby preventing the housing from corroding and enhancing the reliability of the housing.
If the housing is made of iron-based material or copper-based material and the positive electrode is electrically connected to the housing, and if the housing made of iron-based material or copper-based material is at a high potential, oxidation reaction may occur and cause that the housing made of iron-based material or copper-based material to corrode. In light of the above, under the circumstances, the housing may be set to be electrically connected to the negative electrode, that is, the housing is electrically connected to the negative electrode through the first terminal, so as to prevent the housing made of iron-based material or copper-based material from having a high potential, thereby preventing the housing from corroding and enhancing the reliability of the housing.
In specific implementation, in the embodiment of the disclosure, as shown in
That is to say, when setting the fuse structure, to allow the fuse structure to electrically connect the first terminal and the housing, the fuse structure can be implemented in two manners as follows.
Method 1: The fuse structure electrically connects the first terminal and the cover plate. Specifically, since the cavity is electrically connected to the cover plate, and since the cover plate is part of the housing, the fuse structure can realize electrical connection between the first terminal and the housing.
Method 2: The fuse structure is electrically connected to the first terminal and the cavity. Specifically, likewise, since the cavity is electrically connected to the cover plate, and since the cavity is part of the housing, the fuse structure can realize electrical connection between the first terminal and the housing.
In actual situations, the above method 1 and method 2 can be selected according to actual needs, battery design mode, etc., to meet the needs of different application scenarios and improve design flexibility.
Optionally, in the embodiment of the disclosure, both the cavity and the cover can be made of conductive materials. Under the circumstances, insulating films can be provided on the outer surface of the cavity and the surface on one side of the cover plate facing away from the cavity. Specifically, the insulating film can be made of inorganic materials or organic materials with insulating properties, as long as the insulating properties can be achieved, and the disclosure provides no limitation to the specific production materials. In this way, insulation between two adjacent batteries can be achieved, and short circuits between adjacent batteries can be avoided, thereby facilitating assembly of multiple batteries.
Specifically, in the embodiment of the disclosure, the position of the fuse structure may be set as described in the conditions below.
Condition 1: Optionally, in the embodiment of the disclosure, as shown in
In addition, because the fuse structure is arranged outside the housing, the battery module can be repaired and replaced more simply, quickly and effectively when the battery module is repaired in the future, which improves the after-sales maintenance efficiency of the battery module and even the battery pack.
Specifically, in the embodiment of the disclosure, as the partial structural diagram corresponding to the first terminal shown in
In details, the insulating block 13 has a second through hole k2, and the first through hole k1 overlaps the second through hole k2 in a direction perpendicular to the surface of the first terminal 31, so that one end of the rivet 31b can pass through the first through hole k1 and the second through hole k2 in sequence to be electrically connected to the first pole 31a. The other end of the rivet 31b may be directly electrically connected to the first electrode (as shown in
2). In this way, the electrical connection between the electrode and the pole can be realized through the rivet, which facilitates the subsequent implementation of the batteries in series or in parallel.
To be precise, optionally, the arrangement of the partial structure corresponding to the first terminal is basically similar to the arrangement of the partial structure corresponding to the second terminal. For the partial structure corresponding to the second terminal, please refer to
Condition 2: Optionally, in the embodiment of the disclosure, as shown in
In details, the direction M in
Specifically, in the embodiment of the disclosure, as shown in
In specific implementation, in the embodiment of the disclosure, as shown in
Since the fuse structure includes a through hole or a through slot, and is a conductive structure, with the configuration of the through hole or through slot, the surface area of the conductive structure can be reduced, so that the resistance of the conductive structure increases. When a large current passes through the fuse structure, since the resistance is large, more heat can be released. When the current passing through is large enough to cause the conductive structure to fuse, that is, the current passing through the conductive structure is greater than the fuse point of the conductive structure, which causes the conductive structure to fuse, the housing is disconnected from the first terminal, such that insulation is realized, thus protecting the housing from damage and preventing occurrence of worse situation, thereby improving the safety and stability of the battery.
Specifically, in an embodiment of the disclosure, the fuse structure includes: two first divisions extending in a first direction and arranged in parallel, and at least one second division extending in a second direction. One of the first divisions is electrically connected with the first terminal, and the other one of the first divisions is electrically connected with the housing; the second division is electrically connected between the two first divisions; and the first direction intersects the second direction.
For example, as shown in
In this way, current can flow from one of the first divisions to the other first division through the second division, such that the current can reach the housing from the first terminal, thus forming the conductive path.
Certainly, the position and number of the second division are not limited to those shown in
It should be noted that, optionally, as shown in
Specifically, the direction M in
Optionally, in the embodiment of the disclosure, the fuse structure is a conductive structure or a wire. The battery further includes an insulating structure that wraps the fuse structure. For example, as shown in
Since the fuse structure is a conductive structure or a wire, the material adopted for forming the fuse structure can be selected from conductive metal, conductive metal oxide, or other conductive inorganic materials. The property of conductive materials causes the conductive materials to be more likely to be oxidized or corroded, resulting in a decrease in the conductivity of the fuse structure, which reduces the chemical corrosion resistance performance of the housing.
Moreover, for conductive materials, especially some conductive metals which normally have higher thermal conductivity, if the battery is in an environment with high temperature, the bare fuse structure (that is, the fuse structure that is not protected by an insulating structure) is affected by the temperature of surrounding environment, and thus is more likely to be fused, which leads to the decrease in chemical corrosion resistance performance of the housing.
Therefore, by wrapping the insulation structure on the surface of the fuse structure, the insulation structure can protect the fuse structure from corrosion and oxidation whiling preventing the fuse structure from being affected by the surrounding environment, thus providing better protection and heat insulation function for the fuse structure, so as to ensure good electrical conductivity of the fuse structure and ensure that the housing has good chemical corrosion resistance performance.
Optionally, in the embodiment of the disclosure, in addition to the first electrode and the second electrode, the electrode element may also include an electrolyte, a diaphragm, and other structures, and the first electrode and the second electrode can be separated through the diaphragm, thereby preventing the contact between the first electrode and the second electrode. Ion transmission can be achieved through the electrolyte, so that ions can be transmitted between the first electrode and the second electrode.
Specifically, the specific arrangement of each structure in the electrode element can be set according to actual needs. For details, please refer to the related art, and no further description is narrated herein.
Based on the same concept for the disclosure, an embodiment of the disclosure provides a battery module, as shown in
Optionally, in an embodiment of the disclosure, as shown in
Optionally, in an embodiment of the disclosure, as shown in
To be precise, optionally, on the wire bundling plate, a through hole k0 may be provided corresponding to the setting position of each fuse structure, that is, the through hole and the fuse structure are arranged in a one-to-one configuration. Although only one through hole is shown in
Specifically, as shown in
Specifically, in actual situations, when the battery module confronts squeezing, impact, foreign object intrusion or other abnormal conditions, damage is likely to be caused to the insulation film of the battery adjacent to another battery and arranged in series configuration in the battery module, or other situation may be caused and result in insulation failure, which then causes short circuit in the battery module. Under the circumstances, the short circuit can be disconnected by the fusing of the fuse structure, thereby avoiding safety risks such as ignition or thermal runaway of the battery module.
In details, the short circuit that occurs can involve the following situations.
Condition 1: Please refer to
Condition 2: Please refer to
In the actual condition, no matter which of the above situations occurs, by providing a fuse structure in the battery, and when the current between the housing and the first terminal is greater than the preset fuse point, it is possible to control the housing to be insulated from the first terminal, that is, to disconnect the electrical connection between the housing and the first terminal, thus cutting off the conductive path between the first terminal and the housing. In this way, it is possible to avoid damage to the housing due to excessive current, thereby avoiding damage to the battery and improving safety and stability of the battery.
Based on the same concept of the disclosure, an embodiment of the disclosure provides a battery pack, as shown in
Optionally, in the embodiment of the disclosure, as shown in
Certainly, in actual situations, in addition to the battery module and the tray, the battery pack also includes other structures for assembling the battery pack. For details, please refer to the related art, and no further description is narrated herein.
Apparently, those skilled in the art can make various changes and modifications to the disclosure without departing from the spirit and scope of the disclosure. Accordingly, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and equivalent technologies, the present disclosure is also intended to involve these modifications and variations.
Number | Date | Country | Kind |
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202022373057.X | Oct 2020 | CN | national |