ELECTROCHEMICAL APPARATUS AND ELECTRONIC DEVICE

An electrochemical apparatus includes a first electrode plate and a second electrode plate separated by a separator, and a first tab adhesive and a first electrode plate adhesive. The first electrode plate is provided with a first mounting groove for accommodating the first tab adhesive. The second electrode plate is provided with a second mounting groove on a surface facing the first electrode plate, the first electrode plate adhesive being accommodated in the second mounting groove. With the foregoing structure, the electrochemical apparatus of some embodiments of this application can effectively solve the problem of increased overall thickness of the electrochemical apparatus caused by the provision of the first tab adhesive and the first electrode plate adhesive.

CROSS-REFERENCE TO THE RELATED APPLICATION

This application claims priority to the Chinese Patent Application Ser. No. 202211736594.3, filed on Dec. 31, 2022, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

Some embodiments of this application relate to the field of electrochemical apparatus technologies, and in particular, to an electrochemical apparatus and an electronic device.

BACKGROUND

At present, to enhance the fast charging performance of batteries, the tab-centered structure in lithium-ion batteries has been widely used. In this structure, the tab is welded in the middle of the electrode plate so that the internal resistance of the batteries can be effectively reduced to achieve fast charging. The tab-centered structure solution may easily lead to the risk of short circuit between two electrode plates of different polarities. Therefore, it is necessary to dispose an insulating film in a region of the electrode plate corresponding to the tab to improve the safety performance of the batteries. However, after the electrode plate affixed with the insulating film is wound or stacked, the insulating film causes an increase in the thickness of the electrode assembly, affecting the energy density of the battery.

SUMMARY

A technical problem to be mainly solved by some embodiments of this application is to provide an electrochemical apparatus and an electronic device so as to effectively solve the technical problem of increased thickness of the electrochemical apparatus caused by insulating films.

To solve the foregoing technical problem, a technical solution used in some embodiments of this application is as follows: An electrochemical apparatus is provided, including a first electrode plate and a second electrode plate separated by a separator, where the first electrode plate includes a first tab, a first current collector, and a first active substance layer disposed on a surface of the first current collector, and the second electrode plate includes a second tab, a second current collector, and a second active substance layer disposed on a surface of the second current collector. The electrochemical apparatus further includes a first tab adhesive and a first electrode plate adhesive, the first active substance layer is provided with a first mounting groove and a first groove, the first groove is located between the first mounting groove and the first current collector along a thickness direction of the first electrode plate, the first current collector is partially exposed to the first groove, the first tab is located in the first groove and is connected to the first current collector, and the first tab adhesive is provided in the first mounting groove. The second active substance layer is provided with a second mounting groove, and the first electrode plate adhesive is provided in the second mounting groove. Along a first direction, a projection of the first tab is located in the first electrode plate adhesive and the first tab adhesive, the first direction being a normal direction of a plane on which the first electrode plate is located.

Optionally, along the first direction, a projection of the first tab adhesive is located in the first electrode plate adhesive.

Optionally, along the first direction, a thickness of the first tab adhesive is less than or equal to a depth of the first mounting groove.

Optionally, along the first direction, a thickness H1 of the first tab adhesive satisfies: 6 μm≤H1≤30 μm: and/or a depth H2 of the first mounting groove satisfies: 6 μm≤H2≤50 μm.

Optionally, along a length direction of the first current collector, a width L1 of the first tab adhesive satisfies: 5 mm≤L1≤20 mm; and/or a width L2 of the first mounting groove satisfies: 5 mm≤L2≤25 mm.

Optionally, along the first direction, a thickness of the first electrode plate adhesive is less than or equal to a depth of the second mounting groove.

Optionally, along the first direction, a thickness H3 of the first electrode plate adhesive satisfies: 6 μm≤H3≤30 μm: and/or a depth H4 of the second mounting groove satisfies: 6 μm≤H4≤40 μm.

Optionally, along a length direction of the second current collector, a width L3 of the first electrode plate adhesive satisfies: 7 mm≤L3≤30 mm; and/or a width L4 of the second mounting groove satisfies: 7 mm≤L4≤35 mm.

Optionally, the first electrode plate further includes a third active substance layer, the first current collector is located between the first active substance layer and the third active substance layer, and the third active substance layer is provided with a second groove, the second groove corresponding to the first groove. The electrochemical apparatus further includes a third electrode plate, a second tab adhesive, and a second electrode plate adhesive, where the second electrode plate and the third electrode plate are disposed on two sides of the first electrode plate, respectively: the third electrode plate includes a third current collector and a fourth active substance layer, the fourth active substance layer being disposed on a surface of the third current collector facing the first electrode plate: the second tab adhesive is provided in the third active substance layer; and the second electrode plate adhesive is provided in the fourth active substance layer. Along the first direction, a projection of the first tab is located in the second tab adhesive and the second electrode plate adhesive.

Optionally, along the first direction, a projection of the second tab adhesive is located in the second electrode plate adhesive.

Optionally, along the first direction, a sum of a thickness of the first tab adhesive and a thickness of the second tab adhesive is less than or equal to a depth of the first mounting groove.

Optionally, along the first direction, a sum of a thickness of the first electrode plate adhesive and a thickness of the second electrode plate adhesive is less than or equal to a depth of the second mounting groove.

Optionally, the third active substance layer is provided with a third mounting groove, the second groove is located between the third mounting groove and the first current collector, and the second tab adhesive is provided in the third mounting groove.

Optionally, along the first direction, a thickness of the second tab adhesive is less than or equal to a depth of the third mounting groove.

Optionally, along the first direction, a thickness H5 of the second tab adhesive satisfies: 6 μm≤H5≤30 μm; and/or a depth H6 of the third mounting groove satisfies: 6 μm≤H6≤50 μm.

Optionally, the fourth active substance layer is provided with a fourth mounting groove, and the second electrode plate adhesive is provided in the fourth mounting groove.

Optionally, along the first direction, a thickness of the second electrode plate adhesive is less than or equal to a depth of the fourth mounting groove.

Optionally, along the first direction, a thickness H5 of the second electrode plate adhesive satisfies: 6 μm≤H5≤30 μm: and/or a depth H6 of the fourth mounting groove satisfies: 6 μm≤H6≤40 μm.

To solve the foregoing technical problem, another technical solution adopted in some embodiments of this application is to provide an electronic device including the foregoing electrochemical apparatus.

The electrochemical apparatus in some embodiments of this application includes a first electrode plate and a second electrode plate separated by a separator, where the first electrode plate includes a first tab, a first current collector, and a first active substance layer disposed on a surface of the first current collector, and the second electrode plate includes a second tab, a second current collector, and a second active substance layer disposed on a surface of the second current collector. The electrochemical apparatus further includes a first tab adhesive and a first electrode plate adhesive. The first active substance layer is provided with a first mounting groove and a first groove running through the bottom of the first mounting groove. The first current collector is partially exposed to the first groove. The first tab is located in the first groove and is connected to the first current collector. The first tab adhesive is provided in the first mounting groove. The second active substance layer is provided with a second mounting groove, and the first tab adhesive is provided in the second mounting groove. Along a first direction, a projection of the first tab is located in the first electrode plate adhesive and the first tab adhesive, the first direction being a normal direction of a plane on which the first electrode plate is located. With the provision of the first mounting groove in the first active substance layer to accommodate the first tab adhesive and the provision of the second mounting groove in the second active substance layer to accommodate the first electrode plate adhesive, the thickness of the electrochemical apparatus can be effectively reduced.

DETAILED DESCRIPTION

For ease of understanding of this application, the following describes this application in more detail with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is referred to as being “fastened to” another element, it may be directly fastened to the another element, or there may be one or more elements in between. When an element is referred to as being “connected to” another element, it may be directly connected to the another element, or there may be one or more element in between. In the descriptions of this application, the orientations or positional relationships indicated by the terms “up”, “down”, “inside”, “outside”, “perpendicular”, “horizontal”, and the like are based on the orientations or positional relationships shown in the accompanying drawings. Such terms are intended merely for the ease and brevity of description of this application without indicating or implying that the apparatuses or components mentioned in this application must have specified orientations or must be constructed and operated in the specified orientations, and therefore shall not be construed as any limitations on this application. In addition, the terms “first” and “second” are merely intended for a purpose of description and shall not be understood as an indication or implication of relative importance.

Unless otherwise defined, all technical and scientific terms used herein shall have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are merely intended to describe specific embodiments but not to constitute any limitations on this application. The term “and/or” used herein includes any and all combinations of one or more associated items that are listed.

In addition, technical features involved in different embodiments of this application that are described below may be combined as long as they do not conflict with each other.

In order to enhance the charging performance of the electrochemical apparatus, the tab is generally fixed to the current collector by welding. However, even after appropriate treatment processes following welding, sharp burrs may still exist in the welding region. During the assembly process of the electrochemical apparatus, these sharp burrs may easily puncture the separator between the electrode plates of different polarities, causing the separator to lose the ion selection function. This can lead to a short circuit between the positive and negative electrode plates of the electrochemical apparatus, posing a safety hazard. Therefore, it is necessary to dispose tab adhesive in the welding region between the tab and the current collector. However, direct attachment of the tab adhesive can increase the thickness of the electrochemical apparatus and lead to deformation of the electrode plate. In severe cases, it may result in lithium precipitation in the electrochemical apparatus.

To make it easier for the reader to understand the technical solution of this application, the following description uses the first electrode plate10as the negative electrode plate and the second electrode plate20as the positive electrode plate as an example. Referring toFIG.1, the electrochemical apparatus100includes a first electrode plate10, a second electrode plate20, a separator80, a first tab adhesive40, and a first electrode plate adhesive50. The separator80is disposed between the first electrode plate10and the second electrode plate20. The first electrode plate10includes a first tab11, a first current collector12, and a first active substance layer13disposed on at least one surface of a first current collector12. The second electrode plate20includes a second tab, a second current collector21, and a second active substance layer22disposed on at least one surface of a second current collector21.

In an embodiment of this application, the first active substance layer13is provided with a first mounting groove131and a first groove132. Along a thickness direction of the first electrode plate10, the first groove is disposed between the first mounting groove and the first current collector so that the first current collector12is partially exposed to the first groove132. The first tab11is located in the first groove132and connected to the first current collector12to form electrical conduction. Along the first direction F, a projection of the first groove132is located in the first tab adhesive40. The first tab adhesive40is disposed in the first mounting groove131and is capable of covering at least the region where the first tab11is welded to the first current collector12. The first tab adhesive40can prevent sharp burrs in the welding region where the first tab11is welded to the first current collector12from puncturing the separator80, thereby ensuring that the separator80maintains its ion selection function during assembly of the electrochemical apparatus100. The first direction F is a normal direction of a plane where the first electrode plate10is located. The first direction F is substantially perpendicular to the width direction of the first electrode plate10.

By the provision of the first mounting groove131on the first active substance layer13, the first tab adhesive40can be attached behind the first active substance layer13, and along the first direction F, a thickness of the first tab adhesive40is less than or equal to a depth of the first mounting groove131. This ensures that a surface of the first tab adhesive40is nearly flush with a surface of the first active substance layer13, that is, a height difference between the surface of the first tab adhesive40and the surface of the first active substance layer13is in a range of 0 to 3 micrometers.

In some embodiments, referring toFIG.2, along the first direction F, the thickness H1 of the first tab adhesive40satisfies: 6 μm≤H1≤30 μm: and/or the depth H2 of the first mounting groove131satisfies: 6 μm≤H2≤50 μm. Along an extension direction of the first mounting groove131, a width L1 of the first tab adhesive40satisfies: 5 mm≤L1≤20 mm: and/or a width L2 of the first mounting groove131satisfies: 5 mm≤L2≤25 mm.

However, the provision of the first tab adhesive40in the first mounting groove131leads to a reduction in the space for intercalation or deintercalation of lithium ions on the surface of the first active substance layer13, and the precipitation of lithium ions in the form of lithium metal is very likely to occur during the charging and discharging process of the electrochemical apparatus100, commonly known as lithium precipitation in the battery industry. To avoid the phenomenon of lithium precipitation, it is necessary to dispose the first electrode plate adhesive50on the surface of the second active substance layer22to correspondingly reduce the space for intercalation or deintercalation of lithium ions on the surface of the second active substance layer22, so as to make the movement of lithium ions of the electrochemical apparatus100in the charging and discharging process to achieve a balance. However, directly disposing the first electrode plate adhesive50on the surface of the second active substance layer22will result in an increase in the thickness of the electrochemical apparatus100. Therefore, in some embodiments of this application, the second active substance layer22is provided with a second mounting groove221, the first electrode plate adhesive50being disposed in the second mounting groove221. Along the first direction F, a thickness of the first electrode plate adhesive50is less than or equal to a depth of the second mounting groove221. This ensures that a surface of the first electrode plate adhesive50is nearly flush with a surface of the second active substance layer22, that is, a height difference between a surface of the first electrode plate adhesive50and a surface of the second active substance layer22is in a range of 0 to 3 micrometers.

The second mounting groove221is provided in the second active substance layer22instead of the first active substance layer to avoid exacerbation of the lithium precipitation that would occur if the second mounting groove221is provided in the first active substance layer13.

In some embodiments, still referring toFIG.2, along the first direction F, the thickness H3 of the first electrode plate adhesive50satisfies: 6 μm≤H3≤30 μm: and/or the depth H4 of the second mounting groove221satisfies: 6 μm≤H4≤40 μm. Along an extension direction of the second mounting groove221, a width L3 of the first electrode plate adhesive50satisfies: 7 mm≤L3≤30 mm: and/or a width L4 of the second mounting groove221satisfies: 7 mm≤L4≤35 mm.

Through the provision of the first mounting groove131in the first active substance layer13to accommodate the first tab adhesive40, and the provision of the second mounting groove221in the second active substance layer22to accommodate the first electrode plate adhesive50, the thickness of the electrochemical apparatus100can be effectively reduced to enable the electrochemical apparatus100to be adaptable to a wider range of usage scenarios. In addition, to reduce the probability of lithium precipitation occurring in the electrochemical apparatus100, along the first direction F, a projection of the connection region between the first tab11and the first current collector12is located in the first tab adhesive40and the first electrode plate adhesive50.

In some embodiments, referring toFIG.2, along the first direction F, a projection of the first tab adhesive40is located in the first electrode plate adhesive50. In other words, the coverage range of the first electrode plate adhesive50on the second active substance layer22is greater than the coverage range of the first tab adhesive40on the first active substance layer13. During the charging and discharging process of the electrochemical apparatus100, the intercalation or deintercalation movement of the lithium ions is usually perpendicular to a surface of the current collector. However, in the edge region of the tab adhesive or electrode plate adhesive, the lithium ions also undergo diffusion movement: that is, the lithium ions move from the edge of the tab adhesive or electrode plate adhesive, bypassing the tab adhesive or the electrode plate adhesive, and move toward the adjacent active substance layer, resulting in lithium precipitation caused by the insufficiency of the space for intercalation of lithium ions. Therefore, to reduce the probability of lithium precipitation of the electrochemical apparatus100, an area of the first electrode plate adhesive50needs to be larger than an area of the first tab adhesive40, that is, the projection of the first tab adhesive40is located in the first electrode plate adhesive50.

Referring toFIG.3, the first electrode plate10further includes a third active substance layer14, the first current collector12being located between the first active substance layer13and the third active substance layer14. The third active substance layer14is provided with a second groove141corresponding to the first groove132, the first current collector12being partially exposed to the second groove141. The first current collector12is disposed in a bent way in the second groove141to enable the first current collector12to produce a mounting space, which facilitates the provision of the first tab11on the surface of the first current collector12.

The electrochemical apparatus100further includes a third electrode plate30, a second tab adhesive60, and a second electrode plate adhesive70. The second electrode plate20and the third electrode plate30are located on two sides of the first electrode plate10, respectively. The third electrode plate30includes a third current collector31and a fourth active substance layer32. The fourth active substance layer32is disposed on a surface of the third current collector31facing the first electrode plate10. The second tab adhesive60is attached to the third active substance layer14. The second electrode plate adhesive70is attached to the fourth active substance layer32. In addition, along the first direction F, a projection of the first tab11is located in the second tab adhesive60and the second electrode plate adhesive70. The second tab adhesive60is configured to cover a surface of the first current collector12exposed in the second groove141, preventing direct exposure of the first current collector12. Along the first direction F, a projection of the second tab adhesive60is located in the second electrode plate adhesive70. A coverage area of the second electrode plate adhesive70is larger than a coverage area of the second tab adhesive60. The second electrode plate adhesive70is configured to cover a portion of the fourth active substance layer32to reduce the space for intercalation or deintercalation of lithium ions in the fourth active substance layer32, avoiding lithium precipitation in the third electrode plate30.

It should be understood that when the electrochemical apparatus100is a stacked structure, the second electrode plate20and the third electrode plate30have the same polarity and are independent of each other. When the electrochemical apparatus100is a wound structure, the second electrode plate20and the third electrode plate30are portions of the same electrode plate from a partial perspective after winding, where the third current collector31in the third electrode plate30is the same current collector as the second current collector21, and the fourth active substance layer32is the same active substance layer as the second active substance layer22.

In some embodiments, referring toFIG.3, the electrochemical apparatus100is provided with the first mounting groove131to accommodate the first tab adhesive40only in the first active substance layer13, and is provided with the second mounting groove221to accommodate the first electrode plate adhesive50only in the second active substance layer22. The third active substance layer14and the fourth active substance layer32are not provided with a mounting groove. To reduce the thickness of the electrochemical apparatus100, along the first direction F, a sum of the thickness of the first tab adhesive40and a thickness of the second tab adhesive60is less than or equal to the depth of the first mounting groove131. A sum of a thickness of the first electrode plate adhesive50and the thickness of the second electrode plate adhesive70is less than or equal to a depth of the second mounting groove221. The first electrode plate10, the second electrode plate20, the third electrode plate30, and a plurality of separators80need to be compressed along the first direction F after being stacked or wound. As a result, with the increased depth of the first mounting groove131, after the first electrode plate10undergoes a deformation, the impact of the thickness of the second tab adhesive60can be mitigated by the first mounting groove131even though the third active substance layer14is not provided with a corresponding mounting groove to accommodate the second tab adhesive60. Similarly, with the increased depth of the second mounting groove221, after the first electrode plate10undergoes a deformation, the impact of the thickness of the second electrode plate adhesive70can be mitigated by the second mounting groove221even though the fourth active substance layer32is not provided with a corresponding mounting groove to accommodate the second electrode plate adhesive70. Through the increase in the depth of the first mounting groove131and the depth of the second mounting groove221, the impact of the second tab adhesive60and the second electrode plate adhesive70on the thickness of the electrochemical apparatus100can be reduced. Additionally, the need to open corresponding mounting grooves on the third active substance layer14and the fourth active substance layer32can be eliminated, enhancing productivity.

In some embodiments, referring toFIGS.4and5, the third active substance layer14is provided with a third mounting groove142, the second groove141runs through the bottom of the third mounting groove142, and the third mounting groove142is configured to accommodate the second tab adhesive60. Along the first direction F, a thickness of the second tab adhesive60is less than or equal to a depth of the third mounting groove142. This ensures that a surface of the second tab adhesive60is nearly flush with a surface of the third active substance layer14, that is, a height difference between the surface of the second tab adhesive60and the surface of the third active substance layer14is in a range of 0 to 3 micrometers. In an embodiment, along the first direction F, the thickness H5 of the second tab adhesive60satisfies: 6 μm≤H5≤30 μm: and/or the depth H6 of the third mounting groove142satisfies: 6 μm≤H6≤50 μm. Along an extension direction of the third mounting groove142, a width L5 of the second tab adhesive60satisfies: 5 mm≤L5≤20 mm: and/or a width L6 of the second mounting groove221satisfies: 5 mm≤L6≤25 mm.

In some embodiments, still referring toFIGS.4and5, the fourth active substance layer32is provided with a fourth mounting groove321, and the fourth mounting groove321is configured to accommodate the second electrode plate adhesive70. Along the first direction F, a projection of the first tab11is located in the second tab adhesive60and the second electrode plate adhesive70, and a coverage area of the second electrode plate adhesive70is larger than a coverage area of the second tab adhesive60. Along the first direction F, a thickness of the second electrode plate adhesive70is less than or equal to a depth of the fourth mounting groove321. This ensures that a surface of the second electrode plate adhesive70is nearly flush with a surface of the fourth active substance layer32, that is, a height difference between the surface of the second electrode plate adhesive70and the surface of the fourth active substance layer32is in a range of 0 to 3 micrometers. In an embodiment, along the first direction F, the thickness H5 of the second electrode plate adhesive70satisfies: 6 μm≤H5≤30 μm: and/or the depth H6 of the fourth mounting groove321satisfies: 6 μm≤H6≤40 μm. Along an extension direction of the fourth mounting groove321, a width L7 of the second electrode plate adhesive70satisfies: 7 mm≤L7≤30 mm: and/or a width L8 of the fourth mounting groove321satisfies: 7 mm≤L8≤35 mm.

The electrochemical apparatus100in some embodiments of this application includes a first electrode plate10and a second electrode plate20separated by a separator80, where the first electrode plate10includes a first tab11, a first current collector12, and a first active substance layer13disposed on a surface of the first current collector12, and the second electrode plate20includes a second tab, a second current collector21, and a second active substance layer22disposed on a surface of the second current collector21. The electrochemical apparatus100further includes a first tab adhesive40and a first electrode plate adhesive50. The first active substance layer13is provided with a first mounting groove131and a first groove132running through the bottom of the first mounting groove131. The first current collector12is partially exposed to the first groove132. The first tab11is located in the first groove132and is connected to the first current collector12. The first tab adhesive40is disposed in the first mounting groove131. The second active substance layer22is provided with a second mounting groove221, and the first electrode plate adhesive50is disposed in the second mounting groove221. Along a first direction F, a projection of the first tab11is located in the first electrode plate adhesive50and the first tab adhesive40, the first direction F being a normal direction of a plane where the first electrode plate10is located. Through the provision of the first mounting groove131in the first active substance layer13to accommodate the first tab adhesive40and the provision of the second mounting groove221in the second active substance layer22to accommodate the first electrode plate adhesive50, the thickness of the electrochemical apparatus100can be effectively reduced.

This application further provides an embodiment of an electronic device, where the electronic device includes an electrochemical apparatus. For the structure and function of the electrochemical apparatus, refer to the foregoing embodiments. Details are not repeated herein.

The foregoing descriptions are merely some embodiments of this application, but are not intended to limit the patent scope of this application. Any equivalent structural transformations or equivalent process transformations made by using the content of the specification and drawings or direct or indirect application of the content of the specification and drawings to other related technical fields should fall within the patent protection scope of this application.