Experiment method for monitoring cathode lithium precipitation via use of reference electrode

Abstract

The invention discloses an experiment method for monitoring cathode lithium precipitation via use of a reference electrode. The method comprises the following steps: a brass wire of a certain dimension is used as a substrate and is pre-embedded in an electrical core during electrical core making processes, the electrical core is adjusted to a certain charging state after the electrical core makingprocesses are finished, the brass wire is subjected to electrochemical deposition of lithium, a uniform lithium layer of a certain thickness is obtained, and therefore the reference electrode is obtained; a three electrode battery is connected with charge-discharge equipment, a current is applied to an anode and a cathode, electric potential change of a whole battery is monitored via user of thereference electrode during battery charging and discharging processes, and accuracy is confirmed; at last whether lithium precipitation occurs in the cathode of the battery is analyzed. The beneficialeffects of the method are that the electric potential change of all electrodes in the battery can be monitored via use of the reference electrodes through an electrochemical method, and breakdown points of cathode lithium precipitation can be determined; compared with a conventional disassembling observation method, the method disclosed in the invention is advantaged by simplicity, convenience, high credibility and high practicality.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to an experimental method for monitoring negative electrode lithium separation by using a reference electrode. Background technique [0002] Lithium-ion batteries are widely used in notebook computers, mobile phones, cameras, instruments, electric tools and other terminals due to their excellent characteristics such as high energy density, high output voltage, low self-discharge rate, long service life, no memory effect and environmental friendliness. equipment. Its market share continues to expand, gradually replacing nickel-cadmium (Ni-Cd) and metal nickel-hydride (Ni-MH) batteries, occupying a dominant position. [0003] At present, there are soft packs, steel shells, aluminum shells and other types of lithium-ion batteries on the market. Among them, soft-packed lithium-ion batteries have the advantages of good safety performance, light weight, large capacity, smal...

AI Technical Summary

Problems solved by technology

The deposited lithium reacts with the electrolyte to consume active lithium, resulting in the loss of active lithium and the thickening of the SEI film on the surface, resulting in the loss of battery capacity and the reduction of battery life

In addition, the growth of lithium dendrites on the negative electrode and the formation of dead lithium can easily pierce the separator and cause a short circuit between the positive and negative electrodes of the battery, which in turn leads to safety issues.

[0006] Because lithium metal is very active, it reacts immediately when exposed to air, and is not sensitive to electrons, so it is difficult to monitor it. It is difficult to monitor the lithium precipitated from the negative electrode by means of energy spectroscopy and XRD.

At present, the detection method of lithium ionization at the negative electrode of lithium-ion batteries is relatively simple, mainly through dismantling the battery and observing the morphology of the negative electrode sheet for analysis. The microscope observed that the safety of the battery may have been compromised at this point

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