Sectional type interval coating pole piece and naked battery cell

Abstract

The invention relates to the technical field of batteries, and discloses a sectional type interval coating pole piece and a naked battery cell. The sectional type interval coating pole piece comprises a current collector, material areas and empty foil areas are arranged on the front face and the back face of the current collector, the material areas are arranged at intervals in the length direction of the current collector, and the empty foil areas are arranged around the material areas. The interval length of every two adjacent material areas increases progressively according to an arithmetic progression. And the material area and the empty foil area are separated from each other to prevent material falling when the pole piece is folded. The invention further provides a naked battery cell, the naked battery cell comprises the pole pieces and the diaphragms which are coated at intervals in a sectional mode, and the positive pole pieces, the negative pole pieces and the diaphragms are stacked in a layered mode and then continuously wound in the same direction to form a naked battery cell body; the cross section of the bare cell main body is rectangular, and the rectangular bare cell overcomes the defect of the arc end of the bare cell in the prior art, ensures that the CB value of the bare cell does not deviate from the design value, ensures that the current densities at the two sides of the current collector are consistent, and prevents voltage instability caused by voltage polarization.

Description

Technical field [0001] The present invention relates to the field of battery technology, and more particularly to a segmented interval coating plate and a bare core. Background technique [0002] Lithium-ion batteries are a wide range of rechargeable batteries, and the lithium ion battery mainly includes a positive electrode plate and a negative electrode sheet, an electrolyte, a diaphragm, and structural member. [0003] In the prior art, a method of continuously coating the corresponding substrate is continuously applied to the corresponding substrate, and then the substrate is cut into the desired size, and the pole sheets in the lithium ion cell are produced. The positive electrode plate, the negative electrode plate, and the diaphragm are then made into a bare-electrical core, a bare core, and a structural member, a battery cell of a lithium ion battery. When charging, the electrons enter the external circuit from the positive electrode region through the positive electrode ...

AI Technical Summary

Problems solved by technology

This structure will have the following defects: 1. The curvature of the inner side of the winding is relatively large, which will cause material drop during the folding process of the pole piece, posing a safety hazard

2. The inner and outer dressing states of the arc formed by the side pole pieces are different, which causes the CB value here (the excess ratio of the negative electrode capacity per unit area to the positive electrode capacity) to deviate from the design value, which makes it easy to be damaged

3. During the charge and discharge process, the arc on the side is easy to deform and twist, resulting in a decrease in the performance of the battery cell, and even a potential safety hazard

4. During the discharge process, the current density on both sides of the current collector is different, the voltage polarization is large, and the discharge voltage is unstable

5. The commonly used structural parts are regular cuboids, and the arcs on both sides of the bare cells will cause waste of internal space in the structural parts, and the volumetric energy is low

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