A kind of nickel-plated copper material and its preparation method and application

Abstract

The invention relates to a nickel-plated copper material and a preparation method and application thereof, belonging to the technical field of battery manufacturing. The nickel-plated copper material of the present invention comprises pure copper, a copper-nickel alloy layer, a dark nickel layer, and a high-solderability nickel layer sequentially from the inside to the outside; wherein the thickness of the copper-nickel alloy layer is 0.2-0.6 μm, and the thickness of the dark nickel layer is The thickness of the high solderability nickel layer is 0.6-2.6 μm. In the present invention, activated pure copper is used as the base material. First, a pulse power supply is used to apply a small current to electrodeposit a dark nickel layer, and then a high-current-density DC nickel plating is performed in an electrolyte containing a high-weldability nickel-plating additive, and the electroplating is completed. Finally, supplemented by annealing treatment and dehydrogenation heat treatment that match the electroplating process, a nickel-plated copper material with strong coating adhesion, corrosion resistance, folding resistance, and easy welding is obtained. When the nickel-plated copper material prepared by the invention is used for tabs of nickel-plated copper strips of high-rate lithium-ion batteries, its performance is far superior to similar products. The preparation process of the invention is simple and controllable, and is convenient for realizing industrialized production.

Description

technical field [0001] The invention relates to a nickel-plated copper material and a preparation method and application thereof, belonging to the technical field of battery manufacturing. Background technique [0002] At present, it is difficult for commercial lithium-ion batteries to achieve continuous discharge at a rate above 20C. The main reason is that when the battery is discharged at a high rate, the tabs heat up severely, and the overall temperature of the battery is too high, which makes the battery prone to thermal runaway, which leads to the battery rate. Discharge performance and cycle performance deteriorate. Conventional lithium-ion battery manufacturers use nickel lugs for the negative electrode, which has poor conductivity, with a conductivity of 1.4×10 5 S / cm, the positive electrode uses aluminum lugs, and its conductivity is 3.69×10 5 S / cm. During high-rate discharge, due to the low electrical conductivity and poor thermal conductivity of the negative t...

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Problems solved by technology

[0004] Invention patent CN 102330124 A relates to a process of pulse electrochemical deposition and structure adjustment of nickel-plated copper strip. The cold rolling process in the process is easy to cause damage to the nickel coating due to physical damage, reducing the corrosion resistance of the material; the invention patent CN101245480 A discloses a method for preparing a nickel coating on the metal surface. Before the tin layer was firstly plated, after the nickel layer was plated, potassium dichromate passivation, hydrogen removal heat treatment and high-temperature annealing diffusion heat treatment were used. A large number of experiments showed that the nickel coating after passivation could not be tinned; invention patent CN 101705509 A discloses a low-stress nickel plating process, which is mainly used in the anti-corrosion field of high-strength stainless steel. Its innovations include hydrogen removal heat treatment before and after electroplating of materials, eliminating the hydrogen evolution internal stress of materials, and preventing hydrogen evolution corrosion

Due to the different requirements for nickel plating on nickel-plated copper lugs and nickel-plated metal products in other fields, common process methods cannot meet the requirements for producing high-rate lithium-ion battery negative pole lugs.

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