Method and additive for preparing electrolytic copper foil for high temperature power battery with high elongation

Abstract

The invention discloses a method and an additive for preparing an electrolytic copper foil for a high temperature power battery with high elongation. The method comprises the following steps: at first, heating and dissolving a high-purity copper wire to generate copper sulfate electrolyte; then, filtering the prepared copper sulfate electrolyte, filling the filtered copper sulfate electrolyte intoa head tank, adding the additive in the head tank, and carrying out electrolysis to generate the foil; and finally, treating the prepared copper foil through anti-oxidation liquid. The additive comprises a grain refiner, wherein the grain refiner is the aqueous solution of polyethyleneimine derivative, HP, polyethylene glycol and ethylene thiourea. According to the method, the tailor-made additive is added during the electrolytic copper foil preparing process, the prepared copper foil has high elongation at both room temperature and high temperature, the electrolytic copper foil can prevent the copper fol from cracking after the copper foil is coated with an active substance and is rolled by a roller and is in other flattening procedures; and during an overcharging characteristic test, the copper foil can bear the swelling stress caused by heating of overcharging and does not crack.

Description

technical field [0001] The invention relates to the technical field of electrolytic copper foil preparation, in particular to a preparation method of electrolytic copper foil for high temperature and high elongation power batteries. Background technique [0002] Lithium battery copper foil can be divided into two categories: power battery and non-power battery (such as 3C, energy storage, etc.). Due to the large amount of lithium batteries used in new energy vehicles, high energy density and cycle times, and high temperatures during operation or manufacturing, these put forward higher requirements for lithium battery copper foils for power batteries: 1) Yield strength requirements higher. When new energy vehicles use new anode materials in pursuit of high energy density, higher requirements are placed on the yield strength of copper foil (ie, the stress against micro-plastic deformation). 2) Higher requirements for high temperature stability. For example, in the productio...

AI Technical Summary

Problems solved by technology

[0003] If the good elongation rate of the electrolytic copper foil cannot be guaranteed, the copper foil will crack or break during coating, electric cycle and overcharging, which will cause the negative electrode carbon material on the copper foil to stick and become weak, and increase the contact between the copper foil and the negative electrode. The contact resistance of carbon materials will reduce the battery capacity and shorten the cycle life, making the battery a waste product, which will affect the performance of electric vehicles

Images