CN-122025655-A - Winding type energy storage component, preparation method thereof and energy storage device

CN122025655ACN 122025655 ACN122025655 ACN 122025655ACN-122025655-A

Abstract

The invention provides a winding type energy storage component, a preparation method thereof and an energy storage device, wherein the winding type energy storage component comprises a winding core main body, a first lead-out tab and a second lead-out tab, the winding core main body is formed by laminating a layer of composite current collector and a layer of diaphragm, the composite current collector comprises a substrate layer, the substrate layer is provided with a first end face and a second end face which are oppositely arranged, the first end face is provided with a first conductive layer and a first blank area, the first conductive layer is provided with a positive electrode active layer, the second end face is provided with a second conductive layer and a second blank area, the second conductive layer is provided with a negative electrode active layer, orthographic projections of the first blank area and the second blank area on the substrate layer are positioned at two ends of the substrate layer, the first lead-out tab is connected with a part area of the first conductive layer opposite to the second blank area, and the second lead-out tab is connected with a part area of the second conductive layer opposite to the first blank area. The invention improves the energy density of the assembly and the safety of the energy storage device.

Inventors

FAN LINGLING
XIA HENGHENG
YANG ZHONGYANG
ZHANG YUMAN
YAO JINJIN
WU MINGXIA

Assignees

上海奥威科技开发有限公司

Dates

Publication Date: 20260512
Application Date: 20260209

Claims (10)

1. The winding type energy storage assembly is characterized by comprising a winding core main body, a first leading-out tab and a second leading-out tab; The winding core main body is formed by winding a layer of composite current collector and a layer of diaphragm after being overlapped, wherein the composite current collector extends along a first direction and comprises a substrate layer, and the substrate layer is provided with a first end face and a second end face which are oppositely arranged; The first end face is provided with a first conductive layer and a first blank area, the first conductive layer is provided with an anode active layer, the second end face is provided with a second conductive layer and a second blank area, the second conductive layer is provided with a cathode active layer, and orthographic projections of the first blank area and the second blank area on the substrate layer are respectively positioned at two ends of the substrate layer along a first direction; the first lead tab is located at the first end face and is connected with a partial area of the first conductive layer opposite to the second white area, and the second lead tab is located at the second end face and is connected with a partial area of the second conductive layer opposite to the first white area.
2. The wound energy storage assembly of claim 1, wherein the orthographic projections of the positive active layer and the negative active layer on the substrate layer are not contiguous with the orthographic projections of the first whitespace regions on the substrate layer, and are not contiguous with the orthographic projections of the second whitespace regions on the substrate layer.
3. The coiled energy storage assembly according to claim 1 or 2, wherein the distance between the first lead-out tab and the positive electrode active layer is not less than 1mm, and the distance between the orthographic projection of the positive electrode active layer on the substrate layer and the second lead-out tab is not less than 1mm; The distance between the second leading-out tab and the negative electrode active layer is more than or equal to 1mm, and meanwhile, the distance between the orthographic projection of the negative electrode active layer on the substrate layer and the first leading-out tab is more than or equal to 1mm.
4. The wound energy storage assembly of claim 1 or 2, wherein in a first direction, the length of the positive active layer is less than the length of the first conductive layer and the length of the negative active layer is less than the length of the second conductive layer; preferably, the orthographic projection of the negative electrode active layer on the substrate layer covers the orthographic projection of the positive electrode active layer on the substrate layer.
5. The wound energy storage assembly of any one of claims 1-4, wherein the linear lengths of the first and second whitespace zones in the first direction are each independently ≡5mm; preferably, the thickness of the substrate layer is 2-12 μm, and the thicknesses of the first conductive layer and the second conductive layer are 0.1-3.0 μm.
6. The wound energy storage assembly of any one of claims 1-5, wherein an innermost ring of the jellyroll body is wound from the separator or from the composite current collector and the separator simultaneously, the negative active layer in the jellyroll body being proximate to a winding center; at least one circle of the diaphragm is formed by self-winding before the winding core main body finishes winding.
7. The wound energy storage assembly of claim 6, wherein the outer surface of the winding core body is further coated with a negative electrode protective layer, the negative electrode protective layer comprising a metal foil layer and a negative electrode active coating disposed on at least one side surface of the metal foil layer, the negative electrode active coating being proximate the winding core body.
8. A method of making a coiled energy storage assembly according to any of claims 1 to 7, comprising: Coating a first conductive paste and a second conductive paste on partial areas of a first end face and a second end face of a substrate layer respectively to form a first conductive layer and a first blank area on the first end face, and forming a second conductive layer and a second blank area on the second end face, so that orthographic projections of the first blank area and the second blank area on the substrate layer are respectively positioned at two ends of the substrate layer along a first direction to obtain a composite current collector; Coating positive electrode active slurry on the surface of the first conductive layer to form a positive electrode active layer, and coating negative electrode active slurry on the surface of the second conductive layer to form a negative electrode active layer; Providing a first lead tab and a second lead tab, placing the first lead tab on the first end face and welding the first lead tab to a partial area of the first conductive layer opposite to the second blank area, and placing the second lead tab on the second end face and welding the second lead tab to a partial area of the second conductive layer opposite to the first blank area; And providing a diaphragm, laminating the diaphragm with a composite current collector, and then winding to obtain the winding type energy storage component.
9. The production method according to claim 8, wherein the negative electrode active layer is placed on the inner side and the positive electrode active layer is placed on the outer side for winding during the winding treatment.
10. An energy storage device, characterized in that the energy storage device comprises a shell, a winding type energy storage component is arranged in the shell, the winding type energy storage component is the winding type energy storage component according to any one of claims 1-7, and electrolyte or electrolyte is filled in the shell.

Description

Winding type energy storage component, preparation method thereof and energy storage device Technical Field The invention belongs to the technical field of electrochemical energy storage, and relates to a winding type energy storage component, a preparation method thereof and an energy storage device. Background At present, in the subdivision field of medium-high voltage and medium-small capacity, the bipolar internal series structure battery adopts solid electrolyte to realize internal series connection, so that the voltage of the battery is improved, and compared with the traditional electrode, the bipolar internal series structure battery has certain advantages and is widely focused. CN114824154a discloses a bipolar battery, a preparation method and application thereof, and the monomer voltage can reach 6V, even 9V. CN117613193a discloses a bipolar solid-state battery structure without negative sodium ions, and the cell voltage can reach 6-12 v. CN114094170a proposes a "folded" bipolar sodium ion battery structure, the single voltage can reach 9V. However, the existing bipolar inner string structure has obvious disadvantages, such as the need of preventing short circuit by adopting the inner string structure, and the edge of each pole piece is usually sealed by a complex sealing process. The bipolar inner string structure has no gain effect on capacity while increasing voltage, and the capacity needs to be increased by increasing the area of active substances, so that the volume and the weight of a single battery are greatly increased, and furthermore, the capacity needs may need to be met by adopting an external parallel connection mode. Therefore, how to use a good bipolar electrode to increase the energy density of an energy storage assembly is a major concern. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a winding type energy storage component, a preparation method thereof and an energy storage device, wherein a composite current collector adopts a dislocation structure, and a bipolar electrode structure is formed by respectively arranging an anode active layer and a cathode active layer on two sides of the composite current collector and leading out a tab in a dislocation region, so that the energy density of the component is effectively improved. To achieve the purpose, the invention adopts the following technical scheme: The invention provides a winding type energy storage component which comprises a winding core main body, a first leading-out tab and a second leading-out tab, wherein the winding core main body is formed by laminating a layer of composite current collector and a layer of diaphragm and winding, the composite current collector extends along a first direction, the composite current collector comprises a substrate layer, the substrate layer is provided with a first end face and a second end face which are oppositely arranged, the first end face is provided with a first conducting layer and a first white region, the first conducting layer is provided with an anode active layer, the second end face is provided with a second conducting layer and a second white region, the second conducting layer is provided with a cathode active layer, orthographic projections of the first white region and the second white region on the substrate layer are respectively positioned at two ends of the substrate layer along the first direction, the first leading-out tab is positioned at the first end face and is connected with a partial area of the first conducting layer which is opposite to the second white region, and the second conducting layer is positioned at the second end face which is opposite to the first white region. As a preferable technical scheme of the invention, the orthographic projections of the positive electrode active layer and the negative electrode active layer on the substrate layer are not connected with the orthographic projection of the first white-reserving area on the substrate layer, and are not connected with the orthographic projection of the second white-reserving area on the substrate layer. As a preferable technical scheme of the invention, the distance between the first leading-out tab and the positive electrode active layer is more than or equal to 1mm, and the distance between the orthographic projection of the positive electrode active layer on the substrate layer and the second leading-out tab is more than or equal to 1mm. The distance between the second leading-out tab and the negative electrode active layer is more than or equal to 1mm, and meanwhile, the distance between the orthographic projection of the negative electrode active layer on the substrate layer and the first leading-out tab is more than or equal to 1mm. According to the invention, the safe distance is reserved between the edges of the positive electrode active layer and the negative electrode active layer and the lugs on both sides, so that hig