Patent Description:
At present, a conventional battery structure generally uses an adhesive layer to connect a cell with a package casing to prevent the cell from sliding relative to the package casing during the drop so as to prevent head and tail portions of the cell from colliding, which may otherwise result in deformation and hence a short circuit. A pull force generated during the drop acts on a single-sided anode area or on an uncoated aluminum foil of an outer layer of the cell, which will probably tear the aluminum foil. Additionally, in order to prevent the separator from folding during the drop, a few tapes are applied around the head and tail portions of the cell. But the tapes around the head and tail portions will also pull the aluminum foil, and hence have a high probability of tearing the aluminum foil. Many particles and burrs are produced after the aluminum foil is torn, and these particles and burrs probably pierce the separator, thereby leading to a short circuit between the aluminum foil and a copper foil or between a cathode and the copper foil, and eventually causing the cell to heat up and fail.

American patent application <CIT> discloses a rechargeable lithium battery including tape, an electrode assembly, and a case housing the electrode assembly. International patent application <CIT> discloses an electrode assembly with an adhesive coating layer coated on the outer surface of the electrode assembly. Korean patent application <CIT> discloses an electrode laminate in which electrodes and separators are alternately laminated and wound; and an adhesive binder layer surrounding an outer circumferential surface of the electrode laminate.

The present application aims to propose an electrode assembly and a battery including the electrode assembly, and the battery has an advantage of excellent safety performance. The invention is defined in claims <NUM> and <NUM>. Preferred embodiments are defined in claims <NUM>-<NUM>.

For the battery according to the present application, by providing the first area and the second area and connecting the first area with the second area, the adhesion of the second area to the battery is transferred to the first area during the drop of the battery. Therefore, the tear of the electrode assembly due to the drop, which may cause failure of the battery, is avoided.

These and/or additional aspects and advantages of embodiments of the present application will become apparent and more readily appreciated from the following descriptions made with reference to the drawings, in which:.

Embodiments of the present application will be described in detail and examples of the embodiments will be illustrated in the drawings, where same or similar reference numerals are used to indicate same or similar elements or elements with same or similar functions. The embodiments described herein with reference to drawings are explanatory, and only used to generally understand the present application. The embodiments shall not be construed to limit the present application.

The electrode assemblies and batteries according to embodiments of the present application will be described with reference to <FIG>.

<FIG> illustrates a front view of an electrode assembly <NUM> according to an embodiment of the present application. In this embodiment, the electrode assembly <NUM> includes a first electrode sheet and a second electrode sheet spaced apart from each other, and a separator is disposed between the first electrode sheet and the second electrode sheet. The first electrode sheet and the second electrode sheet are wound or stacked to form the electrode assembly. The electrode assembly <NUM> includes a first end portion <NUM>, a second end portion <NUM>, a first main plane <NUM>, a second main plane <NUM>, and a binding layer. The second end portion <NUM> and the first end portion <NUM> are arranged oppositely, and the first main plane <NUM> and the second main plane <NUM> are arranged oppositely. The binding layer includes a first area <NUM> and a second area <NUM>; the first area <NUM> is arranged at the first end portion <NUM> while the second area <NUM> is arranged at the first main plane <NUM>; the first area <NUM> winds around the first end portion <NUM> to connect to the second area <NUM>.

By providing the first area <NUM> and the second area <NUM> and connecting the first area <NUM> with the second area <NUM>, adhesion of the second area <NUM> to the battery is transferred to the first area <NUM> during the drop of the battery, to avoid tearing the electrode assembly <NUM> due to the drop, which may otherwise cause failure of the battery.

According to another embodiment of the present application, a part of the first area <NUM> may also be arranged at the separator or the first electrode sheet. Therefore an external force received during the use of the electrode assembly can be partially transferred to an interior of the electrode assembly <NUM> through the first area <NUM> which is connected to the second area <NUM>. Optionally, the first area <NUM> may extend from the separator or the first electrode sheet, such that an external force received by the first area <NUM> can also be partially transferred to the interior of the electrode assembly <NUM>.

According to an embodiment of the present application, a first adhesive layer can be provided to a first surface of the first area <NUM> close to the electrode assembly <NUM>, such that the first area <NUM> adheres to the electrode assembly <NUM>. By providing a first surface of the second area <NUM> close to the electrode assembly <NUM> with a second adhesive layer, the second area <NUM> can adhere to the electrode assembly <NUM>. The first area <NUM> and the second area <NUM> can be connected by means of the first adhesive layer or the second adhesive layer, as well. Certainly, according to another embodiment of the present application, the second area <NUM> may be an extension of the first area <NUM> on the first main plane <NUM> of the electrode assembly <NUM>.

<FIG> illustrate a rear view, a top view and a bottom view of the embodiment shown in <FIG>, respectively. Referring to <FIG>, a part of the first area <NUM> can be arranged at the separator or the first electrode sheet, or extend from the separator or the first electrode sheet, and be partially connected to the second area <NUM>. Referring to <FIG>, the first area <NUM> and the second area <NUM> can be partially overlapped and be connected.

Referring to <FIG>, in the electrode assembly <NUM> according to an embodiment of the present application, the binding layer can further include a third area <NUM> arranged at the second end portion <NUM>. The third area <NUM> has a first end arranged at the first main plane <NUM> and a second end arranged at the second main plane <NUM>, that is, the third area <NUM> can be winded around the second end portion <NUM> to connect to the second area <NUM>. Certainly, according to an embodiment of the present application, the third area <NUM> can be formed by extension of the separator or the first electrode sheet, and partially overlapped and connected to the second area <NUM>.

In addition, the electrode assembly according to an embodiment of the present application can further include a tab <NUM> provided to the first end portion <NUM>. The tab <NUM> can include a first tab <NUM> and a second tab <NUM>, and the first tab <NUM> and the second tab <NUM> are both located at one side of the first end portion <NUM>.

Referring to <FIG>, in an a-a' direction, the first area <NUM> may have a width smaller than a width of the second area <NUM>, and the third area <NUM> may have a width smaller than the width of the second area <NUM>. For example, the width of the third area <NUM> may be <NUM>.

According to another embodiment of the present application, in the a-a' direction, the width of the first area <NUM> may be greater than the width of the second area <NUM>, and the width of the third area <NUM> may be greater than the width of the second area <NUM>.

<FIG> illustrates the electrode assembly <NUM> according to an embodiment of the present application. Different from the embodiment shown in <FIG>, the binding layer includes two third areas <NUM> in this embodiment. The two third areas <NUM> are arranged in the a-a' direction shown in <FIG>. Each of the third regions <NUM> is winded around the second end portion <NUM>, and each third region <NUM> has a first end overlapping with and connecting to the second area <NUM>. Moreover, in the a-a' direction, each of the third regions <NUM> may have a width smaller than the width of the second area <NUM>. <FIG> shows a bottom view of the electrode assembly <NUM> according to the embodiment shown in <FIG>, and illustrates two third areas <NUM>.

<FIG> illustrate the electrode assembly <NUM> according to another embodiment of the present application. Different from the embodiment shown in <FIG>, the binding layer further includes a fourth area <NUM>; the fourth area <NUM> is arranged at the second main plane <NUM>, and overlaps with and adheres to a part of the first area <NUM> and a part of the third area <NUM>, respectively.

According to an embodiment of the present application, a third adhesive layer can be provided to a first surface of the fourth area <NUM> close to the electrode assembly <NUM>, such that the fourth area <NUM> adheres to the electrode assembly <NUM>. A fourth adhesive layer can be provided to a second surface of the fourth area <NUM> away from the electrode assembly <NUM>, and the fourth adhesive layer can be used to make the electrode assembly <NUM> adhere to a casing that accommodates the electrode assembly <NUM>. Certainly, according to another embodiment of the present application, the fourth area <NUM> may be an extension of the first area <NUM> on the second main plane <NUM> of the electrode assembly <NUM>; the fourth area <NUM> may be an extension of the third area <NUM> on the second main plane <NUM> of the electrode assembly <NUM>.

Referring to <FIG>, in the a-a' direction, the width of the third area <NUM> may be smaller than a width of the fourth area <NUM>, and the width of the first area <NUM> may be greater than the width of the fourth area <NUM>. According to another embodiment of the present application, the width of the third area <NUM> may be greater than the width of the fourth area <NUM>, and the width of the first area <NUM> may be smaller than the width of the fourth area <NUM>.

Referring to <FIG>, in order to facilitate the arrangement of the tab <NUM>, the first area <NUM> is provided with a through hole <NUM>. That is, when the width of the first area <NUM> is greater than a spacing between the tabs, the tab <NUM> can pass through the through hole <NUM>. The tab <NUM> partially or completely passes through the through hole <NUM>, that is, the through hole <NUM> may be an open or closed hole. <FIG> illustrates a case where the tab <NUM> completely passes through the through hole <NUM>. Thus, the structure described above is applicable to a battery with a narrow spacing between the two tabs <NUM>. Moreover, the operation is simple. Further, a tape is eliminated. And the energy density loss is little.

<FIG> illustrates another embodiment of the present application. According to <FIG>, when the spacing between the tabs is relatively wide, the first area <NUM> can be arranged between the first tab <NUM> and the second tab <NUM>, that is, orthographic projections of the first tab <NUM>, the second tab <NUM> and the second area <NUM> on the first main plane <NUM> do not overlap.

<FIG> illustrates another embodiment of the present application. According to <FIG>, when the spacing between the tabs is relatively narrow, the first tab <NUM> and the second tab <NUM> can be arranged at the same side of the first area <NUM>.

<FIG> illustrates the electrode assembly <NUM> according to another embodiment of the present application. In this embodiment, the second area <NUM> exhibits an irregular pattern (or abnormally shaped), which can be made by cutting a rectangular sheet. For example, the second area <NUM> is constructed by cutting a right angle of the rectangular sheet, and the orthographic projections of the first tab <NUM>, the second tab <NUM> and the second area <NUM> on the first main plane <NUM> do not overlap, thereby reducing an overall thickness of the battery.

<FIG> illustrates the electrode assembly <NUM> according to another embodiment of the present application. In this embodiment, the first area <NUM> can include a first binding unit 130a and a second binding unit 130b, and the first binding unit 130a and the second binding unit 130b connect to the second area <NUM>, respectively. The first binding unit 130a and the second binding unit 130b can be arranged at two sides of the tab <NUM>; or at least one of the first binding unit 130a and the second binding unit 130b can be arranged between the first tab <NUM> and the second tab <NUM>.

Reference throughout this specification to "an embodiment," "some embodiments," "an exemplary embodiment," "an example," "a specific example," or "some examples," means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. Thus, the appearances of the above phrases throughout this specification do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Claim 1:
An electrode assembly (<NUM>), comprising a first electrode sheet, a second electrode sheet, and a separator disposed therebetween, wherein the first electrode sheet and the second electrode sheet are wound or stacked to form the electrode assembly (<NUM>),
wherein the electrode assembly (<NUM>) comprises:
a first end portion (<NUM>) provided with a tab (<NUM>),
a second end portion (<NUM>) arranged opposite to the first end portion (<NUM>),
a first main plane (<NUM>),
a second main plane (<NUM>) arranged opposite to the first main plane (<NUM>), and
a binding layer comprising:
a first area (<NUM>) arranged at the first end portion (<NUM>), and
a second area (<NUM>) arranged at the first main plane (<NUM>),
wherein the first area (<NUM>) is connected to the second area (<NUM>) and
wherein the first area (<NUM>) is provided with a through hole (<NUM>), and the tab (<NUM>) passes through the through hole (<NUM>).