Method for in-situ lithium pre-embedding of lithium ion battery electrode

Abstract

The invention relates to a method for in-situ lithium pre-embedding of a lithium ion battery electrode; the method comprises the following steps that S1, the top end of a metal electrode is connectedwith metal lithium to form a reference electrode, and the reference electrode is inserted into a battery electrolyte through a hole in the surface of a cover plate, wherein the reference electrode isnot in contact with a cell; S2, the negative electrode of the battery serves as a cathode, the reference electrode serves as an anode, small-current charging is adopted, and the negative electrode lithium pre-embedding is carried out; S3, the negative electrode potential change is monitored in real time; when the negative electrode potential is lower than the first end potential, the negative electrode lithium pre-embedding is stopped; S4, the positive electrode of the battery serves as a cathode, the reference electrode serves an anode, small-current charging is adopted, and the positive electrode lithium pre-embedding is carried out; and S5, the positive electrode potential change is monitored in real time; when the positive electrode potential is lower than the second end potential, thepositive electrode lithium pre-embedding is stopped. According to the method disclosed by the invention, in-situ lithium pre-embedding is carried out after the battery is aged, the positive and negative electrode lithium pre-embedding is independently controlled, and meanwhile, the positive electrode potential and the negative electrode potential are monitored in real time, and the lithium embedding amount is reasonably controlled, so that the failure electrode is quickly judged when the positive electrode and the negative electrode are abnormal.

Description

technical field [0001] The invention relates to a method for pre-embedding lithium in situ in electrodes of lithium ion batteries, belonging to the technical field of lithium ion batteries. Background technique [0002] With the development of modern industrial society, the consumption of fossil fuels has increased dramatically, and the fuel consumption of transportation is particularly prominent. As a new type of electric energy storage carrier, lithium-ion battery has attracted people's attention due to its advantages of high voltage, high specific energy, good safety and no pollution. [0003] The first coulombic efficiency of a large-capacity prismatic lithium-ion battery is an important indicator for evaluating the performance of a single battery, and its interface properties are closely related to cycle life. When the lithium-ion battery is pre-charged, the active lithium ions in it come from the extraction of the positive electrode. When the lithium ions are inserted...

AI Technical Summary

Problems solved by technology

The positive electrode pre-intercalation lithium process is generally to add lithium-rich materials to the positive electrode, such as Li 5 FeO 4 , which can release lithium ions during pre-charging, but the reaction is irreversible, and the generated LiFeO 2 will be left in lithium-ion batteries, which will inevitably reduce the energy density of lithium-ion batteries

It should be noted that these methods all pre-intercalate lithium on the positive and negative electrodes, and then assemble them, which have extremely high requirements on the environment and the process is extremely complicated.

[0005] In view of this, the present invention proposes a method for in-situ pre-intercalation of lithium-ion battery electrodes. After the battery is assembled, injected, and aged according to the normal process, it is pre-intercalated with lithium, and at the same time, the potential of the positive and negative electrodes is monitored in real time to prevent Too little or too much lithium intercalation, reasonable control of the amount of lithium intercalation, and rapid judgment of failed electrodes when the positive and negative electrodes are abnormal, so as to effectively solve the shortcomings and limitations of the existing technology

Images