Three-electrode battery and manufacturing method thereof

Abstract

The invention discloses a three-electrode battery. The three-electrode battery comprises an outer shell, a positive electrode, a negative electrode, diaphragms, electrolyte, a reference electrode and a nickel electrode lug; the reference electrode is arranged between the positive electrode and the negative electrode; the diaphragms are arranged respectively between the positive electrode and the reference electrode and between the reference electrode and the negative electrode; the whole three-electrode battery is packaged in the outer shell; and the outer shell is filled with the electrolyte. One end of the reference electrode is a naked copper wire which is completely arranged between the positive electrode and the negative electrode, and the three electrodes are subjected to lithium plating before an AC impedance test; the other end of the reference electrode is a varnished wire; one portion of the varnished wire is immerged in the electrolyte, and the other portion of the varnished wire is located outside the positive electrode and the negative electrode and extends to the outer side of the outer shell to be connected with the nickel electrode lug; and the nickel electrode lug is fixed with the outer shell. The invention also discloses a preparation method of the three-electrode battery. The three-electrode battery has the advantages that the signal interference resistance is strong, the manufacturing cost is low, transmission of the lithium ions between the positive electrode and the negative electrode is guaranteed, in-situ monitoring for the electric potential of the positive electrode, the electric potential of the negative electrode and the impedance of the lithium ion battery in a use process is carried out, the detection accuracy is improved obviously, and the detection efficiency is improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a three-electrode battery and a preparation method thereof. Background technique [0002] Due to the advantages of small size, high energy density, and no pollution to the environment, lithium-ion batteries have been more and more widely used in various electronic products and new energy vehicle industries. Especially with the development of new energy vehicles, lithium-ion batteries are growing explosively, but electric vehicles have higher and higher requirements on the life of lithium-ion batteries, among which the capacity attenuation and power attenuation of batteries are the bottlenecks restricting the further development of electric vehicles. [0003] During the use of lithium-ion batteries, the electrolyte of the battery and the positive and negative electrode materials slowly undergo side reactions, such as electrolyte consumption, negative electrode SEI film thicken...

AI Technical Summary

Problems solved by technology

During the cycle charge and discharge process of lithium-ion batteries, the lithium sheet of the reference electrode will block the transmission of lithium ions, and the corresponding positive and negative electrode areas cannot deintercalate lithium, forming a dead zone. The result of this method is unreliable.

[0005] In a three-electrode assembly method of a flexible-packaged lithium-ion battery (country: China, publication number: CN105470577A, publication date: 2016-04-06), the reference electrode in the three-electrode system is silver wire, gold wire or platinum wire, so The exposed metal wire in the electrolyte will interfere with the electrical signal, and the cost of the three electrodes made of precious metal wire will be relatively high

[0006] A three-electrode battery (country: China, announcement number: CN204130649U, announcement date: 2015-01-28) discloses a three-electrode system, wherein the reference electrode is a micron metal copper wire or a micron metal platinum wire, and its surface Set the lithium plating layer, and the lithium plating on the metal wire or the surface of the metal wire is exposed to the electrolyte, which will interfere with the electrical signals of the positive electrode-reference electrode and the negative electrode-reference electrode of the test through the electrolyte, and the results will be affected. In addition, platinum Wire as a reference electrode is more expensive

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