Flexible low-resistance current collector and preparation method thereof

Abstract

The invention belongs to the technical field of current collectors. The invention provides a flexible low-resistance current collector. The current collector comprises a non-conductive base material and conductive coatings; the two faces of the non-conductive base material are each provided with one conductive coating. The thickness of the non-conductive base material is 1-30 microns; and the thickness of a single surface of each conductive coating is 0.1-4 microns. The invention also provides a preparation method of the flexible low-resistance current collector. The current collector can better adapt to large size change of an electrode material in the working process, and the effective surface area of the current collector for conducting electrons is increased; the mass per unit area of the current collector is small, the mass of a whole electrode is greatly reduced, and the weight is lighter; and the specific surface area of the current collector is large, so that the contact performance of an electrode material and the current collector is effectively improved, the interface resistance between the current collector and the electrode material is reduced, and the rate capability is improved.

Description

technical field [0001] The invention relates to the technical field of current collectors, in particular to a flexible low-resistance current collector and a preparation method thereof. Background technique [0002] Current collectors used in electrochemical systems including lithium-ion batteries, solid-state batteries, supercapacitors and lithium-sulfur batteries are mainly aluminum foil and copper foil. The main function of the current collector is to provide good electronic conduction ability and connect to the external circuit. The existing technology includes directly using aluminum foil, copper foil or other base films with electronic conduction ability as the current collector in the electrochemical system, and also Including the coating modified current collector used to improve the good contact between the current collector and the electrode material attached to the surface of the current collector, improve the electronic conductivity of the interface, and avoid th...

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Problems solved by technology

[0004] The surface conductive layer of the flexible non-conductive current collector used in the above-mentioned published patents is to form a conductive layer on the surface of the flexible non-conductive current collector by means of chemical plating, electroplating or vacuum sputtering. This kind of surface conductive layer treatment method There are the following problems: the adhesion between the conductive layer and the flexible non-conductive current collector is poor, and a metal layer is directly plated on the surface of the non-metallic non-conductive current collector by means of electroless plating, electroplating or vacuum sputtering, because the compatibility of the two layers is poor , the adhesion will be obviously deviated; the adhesion between the metal conductive layer and the electrode material layer during application is poor, resulting in poor electronic conduction ability of the electrode pole piece as a whole, which affects the performance of the electrochemical system under high current charge and discharge conditions; the electrode There will be a certain degree of dimensional change in the material layer during the operation of the battery, which will strengthen the interface connection between the originally weak metal conductive layer and the electrode material layer, resulting in a sharp deterioration in the performance of the electrochemical system; electroless plating, electroplating or both Both conductive layer coating methods will cause harm to the natural environment and the operator's body. The vacuum sputtering process has high costs and cannot be produced in large-scale and high-speed roll-to-roll, so it is not suitable for large-scale applications.

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