Nickel-plated copper material and preparation method and application thereof

Abstract

The invention relates to a nickel-plated copper material and a preparation method and application thereof, and belongs to the technical field of battery manufacturing. The nickel-plated copper material sequentially comprises fine copper, a copper-nickel alloy layer, a dull nickel layer and a high-weldability nickel layer from inside to outside. The thickness of the copper-nickel alloy layer ranges from 0.2 micrometer to 0.6 micrometer. The thickness of the dull nickel layer ranges from 0.2 micrometer to 0.6 micrometer. The thickness of the high-weldability nickel layer ranges from 0.6 micrometer to 2.6 micrometers. The preparation method includes the steps that the activated fine copper serves as a base material; firstly, low current is supplied by a pulse power source to electrically deposit the dull nickel layer; then, direct current nickel plating at high current density is conducted in an electrolyte with high-weldability nickel plating additives; and after electroplating is finished, in combination with annealing treatment and dehydrogenation thermal treatment matched with the electroplating process, the nickel-plated copper material which is strong in coating binding force, resistant to corrosion and folding and easy to weld is obtained. When the prepared nickel-plated copper material is used for nickel-plated copper strip electrode tabs of large-magnifying-power lithium ion batteries, the performance of the electrode tabs are far superior to the performance of similar products. The preparation process is simple and controllable, and industrial production is conveniently achieved.

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...

AI Technical Summary

Problems solved by technology

[0004] The invention patent CN102330124A relates to a pulse electrochemical deposition and tissue adjustment process of nickel-plated copper strip. The cold rolling process is easy to cause damage to the nickel coating due to physical damage, reducing the corrosion resistance of the material; the invention patent CN101245480A discloses a method for preparing a nickel coating on the metal surface. On the tin layer, after the nickel layer is plated, potassium dichromate passivation, hydrogen removal heat treatment and high temperature annealing diffusion heat treatment are used. A large number of experiments have shown that the nickel coating after passivation cannot be tinned; the invention patent CN101705509A discloses a The low-stress nickel plating process is mainly used in the anti-corrosion field of high-strength stainless steel. Its innovations include hydrogen removal heat treatment before and after electroplating to eliminate the hydrogen evolution internal stress of the material and prevent 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.

Images