This application relates to the field of energy storage technologies, and in particular, to an electrochemical apparatus and an electronic device.
With the development of electronic devices, batteries for electronic devices are expected to have larger capacities to satisfy battery life requirements of the electronic devices. A battery for electronic devices generally includes a housing and an electrode assembly that is located inside the housing. The housing plays a role of protecting the electrode assembly. The housing and the electrode assembly may be bonded by using an insulation tape. When the electronic device drops, the insulation tape may possibly tear out the electrode assembly, giving rise to a risk of internal short circuit of the electrode assembly. When the insulation tape is not well bonded, a risk of breaking a top cover may arise, which affects safety of the electronic device.
This application provides an electrochemical apparatus and an electronic device. The electrochemical apparatus is capable of improving reliability of connection between an electrode assembly and a housing, improving drop resistance, and increasing an energy density of the electrochemical apparatus.
A first aspect of this application provides an electrochemical apparatus. The electrochemical apparatus includes a housing, an electrode assembly, and an insulation tape, where at least part of the electrode assembly is located inside the housing, and the insulation tape is located between the housing and the electrode assembly. The insulation tape includes a first surface that is bonded to the electrode assembly and a second surface that is bonded to the housing, the first surface includes a first bonding zone, and the second surface includes a second bonding zone, where an area A of the first bonding zone and an area B of the second bonding zone satisfy 0.08≤B/A≤0.965. In another possible design, 0.15≤B/A≤0.85.
In a possible design, the first bonding zone has a first outer edge, and the second bonding zone has a second outer edge, where a distance between an orthographic projection of the second outer edge onto the first surface and the first outer edge is h, and a width of the first bonding zone is W2, where 0.035×W2≤h≤0.4×W2. In another possible design, 0.05×W2≤h≤0.35×W2.
In a possible design, the electrode assembly has a third surface that is bonded to the insulation tape, and the first bonding zone covers an orthographic projection of the second bonding zone onto the third surface.
In a possible design, the electrode assembly has a third surface that is bonded to the insulation tape, and a length of the third surface is L1; and along a width direction of the electrochemical apparatus, the first bonding zone has a first axis, the third surface has a second axis, and a distance between an orthographic projection of the first axis onto the third surface and the second axis is D, where D≤0.1×L1.
In a possible design, a width of the third surface is W1, and along a length direction of the electrochemical apparatus, the first bonding zone has a third axis, the third surface has a fourth axis, and a distance between an orthographic projection of the third axis onto the third surface and the fourth axis is E, where E≤0.1×W1.
In a possible design, an orthographic projection of a geometric center of the second bonding zone onto the first surface coincides with a geometric center of the first bonding zone. In a possible design, a ratio of a distance from the geometric center of the first bonding zone to the first outer edge along a direction to a distance from the geometric center of the first bonding zone to the second outer edge along the same direction is the same as a ratio of a distance from the geometric center of the second bonding zone to the first outer edge along the direction to a distance from the geometric center of the second bonding zone to the second outer edge along the same direction.
In a possible design, a length of the first bonding zone is L2 and a width of the first bonding zone is W2, where 0.4×L1≤L2≤0.8×L1 and 0.4×W1≤W2≤0.8×W1.
In a possible design, the insulation tape includes a first adhesive, a substrate, and a second adhesive that are laminated, the first adhesive is bonded to the electrode assembly, and the second adhesive is bonded to the housing.
In a possible design, a shape of the first bonding zone and the second bonding zone is selected from any one of square, rectangle, trapezium, octagon, circle, or oval.
A second aspect of this application provides an electronic device, and the electronic device includes the electrochemical apparatus described above.
When the housing of the electrochemical apparatus receives an external force (for example, the housing receives an external force during a drop test), the external force can be transferred from the housing to the second bonding zone of the insulation tape, from the second bonding zone to the first bonding zone, and from the first bonding zone to the electrode assembly. Because the area of the first bonding zone is larger than the area of the second bonding zone, a peeling force per unit area between the first bonding zone and the electrode assembly can be reduced, thereby reducing a risk of the electrode assembly being torn out by the insulation tape under the external force, improving reliability of connection between the electrode assembly and the insulation tape, and further improving safety of the electrode assembly. In addition, when the second surface of the insulation tape that is connected to the housing has a smaller area, the insulation tape is smaller and lighter while reliability of connection between the insulation tape and the housing is ensured, thereby helping increase an energy density of the electrochemical apparatus.
It should be understood that the foregoing general description and the following detailed description are only exemplary and are not intended to limit this application.
The accompanying drawings herein are incorporated into this specification and form a part of this specification, illustrate the embodiments conforming to this application, and are intended to explain the principles of this application together with this specification.
To help better understand the technical solutions of this application, the following describes the embodiments of this application in detail with reference to the accompanying drawings.
Apparently, the described embodiments are merely some rather than all of the embodiments of this application. All other embodiments obtained based on the embodiments of this application shall fall within the protection scope of this application.
The terms used in the embodiments of this application are merely intended to describe specific embodiments, but not intended to limit this application. The terms “a/an”, “the” and “this” of singular forms used in the embodiments and the appended claims of this application are also intended to include plural forms, unless otherwise specified in the context clearly.
It should be understood that in this specification, the term “and/or” is merely an association relationship that describes associated objects, indicating that three relationships may exist. For example, A and/or B may indicate three cases: only A, both A and B, and only B. In addition, the character “/” in this specification generally indicates that associated objects are in an “or” relationship.
It should be noted that the directional terms such as “upper”, “lower”, “left”, and “right” described in the embodiments of this application are described as seen from the angles shown in the accompanying drawings, and should not be understood as limitations to the embodiments of this application. In addition, in the context, it should be further understood that when an element is referred to as being “above” or “under” another element, the element can not only be directly connected “above” or “under” the another element, but also be indirectly connected “above” or “under” the another element through an intermediate element.
An embodiment of this application provides an electrochemical apparatus. As shown in
When the electrochemical apparatus is in a drop test, risks such as breaking of a top cover and peeling of aluminum foil of the electrode assembly 2 are prone to arise, thereby causing short circuit in the electrode assembly 2 and causing damage to the electrochemical apparatus. To resolve this technical issue, as shown in
In this embodiment, an area of the first bonding zone 31 is larger than an area of the second bonding zone 32, that is, an area of a surface where the insulation tape 3 is bonded to the housing 1 is smaller than an area of a surface where the insulation tape 3 is bonded to the electrode assembly 2.
When the housing 1 of the electrochemical apparatus receives an external force (for example, the housing 1 receives an external force during a drop test), the external force can be transferred from the housing 1 to the second bonding zone 32 of the insulation tape 3, from the second bonding zone 32 to the first bonding zone 31, and from the first bonding zone 31 to the electrode assembly 2. Because the area of the first bonding zone 31 is larger than the area of the second bonding zone 32, a peeling force per unit area between the first bonding zone 31 and the electrode assembly 2 can be reduced, thereby reducing a risk of the aluminum foil of the electrode assembly 2 being torn out by the insulation tape 3, improving reliability of connection between the electrode assembly 2 and the insulation tape 3, and further improving safety of the electrode assembly 2. In addition, when the second bonding zone 32 of the insulation tape 3 that is connected to the housing 1 has a smaller area, the insulation tape 3 is smaller and lighter while reliability of connection between the insulation tape 3 and the housing 1 is ensured, thereby helping increase an energy density of the electrochemical apparatus.
Specifically, the area A of the first bonding zone 31 and the area B of the second bonding zone 32 satisfy 0.08≤B/A≤0.965. In a specific embodiment, 0.1≤B/A≤0.6. For example, B/A may be specifically 0.1, 0.3, 0.4, 0.6, 0.8, 0.9, or the like.
In this embodiment, when B/A is excessively large (for example, greater than 0.965), it indicates that the area A of the first bonding zone 31 is close to the area B of the second bonding zone 32. As a result, a peeling force per unit area between an edge of the first bonding zone 31 and the electrode assembly 2 cannot be effectively reduced, thereby increasing the risk of the aluminum foil of the electrode assembly 2 being torn out by the insulation tape 3, and reducing safety of the electrode assembly 2. In addition, the insulation tape 3 is made excessively heavy and excessively large, and the energy density of the electrochemical apparatus is decreased. When B/A is excessively small (for example, less than 0.08), the area B of the second bonding zone 32 is excessively small, which results in a larger peeling force per unit area between the insulation tape 3 and the housing 1, and reduces the reliability of connection.
More specifically, as shown in
In this embodiment, when h is excessively large, it indicates that a difference between the area of the second bonding zone 32 and the area of the first bonding zone 31 is excessively large, that is, an area of a bonding surface between the insulation tape 3 and the housing 1 is excessively small, which causes an excessively large peeling force per unit area between the insulation tape 3 and the housing 1, thereby causing excessively low reliability of connection between the insulation tape 3 and the housing 1. When h is excessively small, it indicates that the difference between the area of the second bonding zone 32 and the area of the first bonding zone 31 is excessively small, that is, an area of the first bonding zone 31 beyond an edge of the second bonding zone 32 is excessively small, which causes an excessively small action area of stress transferred from the edge of the second bonding zone 32 to an edge of the first bonding zone, that is, an excessively large peeling force per unit area between the edge of the first bonding zone 31 of the insulation tape 3 and the electrode assembly 2, thereby causing the aluminum foil of the electrode assembly 2 to be easily torn out by the insulation tape 3. In addition, this further causes the insulation tape 3 to be excessively large and decreases the energy density of the electrochemical apparatus. Therefore, when 0.035×W2≤h≤0.4×W2, the areas of the first bonding zone 31 and the second bonding zone 32 are appropriate, so that connection between the insulation tape 3 and the housing 1 and connection between the insulation tape 3 and the electrode assembly 2 are both more reliable, and the energy density of the electrochemical apparatus can be increased.
A drop test was performed by using a lithium-ion battery whose maximum projection surface is a rectangle to compare drop pass rates. Group 1 has a structure shown in
It can be learnt from the test results in the foregoing table that after the insulation tape 3 of this application is provided such that the area A of the first bonding zone and the area B of the second bonding zone satisfy 0.08≤B/A≤0.965, all the electrochemical apparatuses have relatively high pass rates in the drop test, and have higher pass rates (≥90%) when 0.05×W2≤h≤0.35W2.
In a specific embodiment, as shown in
In this embodiment, when the first bonding zone 31 covers the orthographic projection of the second bonding zone 32 onto the third surface 21, an external force transferred from the second bonding zone 32 can be fully transferred to the first bonding zone 31 via the insulation tape 3 and thereby transferred to the third surface 21 of the electrode assembly 2. This reduces a risk of breaking of the insulation tape 3 under an action of the external force and improves a structural strength and service life of the insulation tape 3, thereby improving reliability of connection between the housing 1 and the electrode assembly 2.
Specifically, as shown in
A distance between D and L1 and a distance between E and W1 can be set as appropriate to the actual situation, as long as reliability of connection between the insulation tape 3 and the electrode assembly 2 can be improved and a risk of breaking them at an edge can be reduced.
In this embodiment, a weight of the electrode assembly 2 at various positions is uneven and the reliability of connection between the insulation tape 3 and the electrode assembly 2 is affected by gravity of the electrode assembly 2. Therefore, when the weight of the electrode assembly 2 is uneven, an impact of the gravity of the electrode assembly 2 on the reliability of connection between the insulation tape 3 and the electrode assembly 2 can be reduced by changing a location of the insulation tape 3 on the third surface 21.
In a possible design, as shown in
In this embodiment, because the orthographic projection of the geometric center of the second bonding zone 32 onto the first surface coincides with the geometric center of the first bonding zone 31, the geometric center of the second bonding zone 32 is located on a same straight line as the geometric center of the first bonding zone 31. Therefore, after the insulation tape 3 is bonded to the housing 1 and the electrode assembly 2, the first bonding zone 31 and the second bonding zone 32 receives relatively even force, which improves a structural strength of the insulation tape 3. In addition, because the ratio of the distance from the geometric center of the first bonding zone 31 to the first outer edge 311 along a direction to the distance from the geometric center of the first bonding zone 31 to a second outer edge 321 along the same direction is the same as the ratio of the distance from the geometric center of the second bonding zone 32 to the first outer edge 311 along the direction to the distance from the geometric center of the second bonding zone 32 to the second outer edge 321 along the same direction, the orthographic projection of the second bonding zone 32 onto the first surface is located in the middle of the first bonding zone 31. This can further improve evenness of a force transferred from the second bonding zone 32 to the first bonding zone 31 and improve the structural strength of the insulation tape 3 and a strength of bonding between the insulation tape 3 and the electrode assembly 2.
In the foregoing embodiments, as shown in
A relationship between L1 and L2 and that between W1 and W2 are not limited to the foregoing relationships, and can be set as appropriate to the actual situation, as long as the reliability of connection between the insulation tape 3 and the electrode assembly 2 can be improved and the electrode assembly 2 can be prevented from being torn out.
In a first specific embodiment, as shown in
In a second specific embodiment, as shown in
In a third specific embodiment, as shown in
As shown in
In this embodiment, the substrate 35 of the insulation tape 3 is capable of playing a role of supporting the first adhesive 33 and the second adhesive 34, thereby improving the structural strength of the insulation tape 3, further reducing a risk of damage to the insulation tape 3 under an action of an external force, and improving reliability of connection between the housing 1 and the electrode assembly 2. In addition, the separately structured insulation tape 3 has advantages of simple structure and convenient processing, and can easily implement that the first bonding zone 31 and the second bonding zone 32 of the insulation tape 3 have different bonding forces.
In the foregoing embodiments, as shown in
The electrochemical apparatus in the embodiments of this application can be used in a plurality of fields. Devices can use the electrochemical apparatus in the embodiments of this application as long as the devices can use electrochemical apparatuses for power supply. For example, the electrochemical apparatus may be used for components such as an electrochemical apparatus and an electronic apparatus of an electric vehicle. The electronic apparatus may be a mobile phone, a tablet computer, a desktop computer, a laptop computer, a handheld computer, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, a cellular phone, a personal digital assistant (PDA), an augmented reality (AR) device, a virtual reality (VR) device, an artificial intelligence (AI) device, a wearable device, an onboard device, a smart home device and/or a smart city device, an electric tool, an energy storage apparatus, an electric tricycle, an electric vehicle, or the like. A specific type of the electronic apparatus is not specially limited in the embodiments of this application.
Specifically, the electronic device may include components such as a housing, a screen, a circuit board, and an electrochemical apparatus, where the screen, circuit board, and electrochemical apparatus are all installed inside the housing, and the electrochemical apparatus is the electrochemical apparatus according to any one of the foregoing embodiments.
The foregoing descriptions are merely preferred embodiments of this application, but are not intended to limit this application. Persons skilled in the art understand that this application may have various modifications and variations. Any modification, equivalent replacement, and improvement made without departing from the spirit and principle of this application shall fall within the protection scope of this application.
This application is the Continuation application of PCT international application: PCT/CN2021/074459 filed on Jan. 29, 2021, the disclosure of which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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Parent | PCT/CN2021/074459 | Jan 2021 | US |
Child | 18128424 | US |