High-precision fixture and method for measuring lithium plug impedance of negative pole piece of lithium ion battery

Abstract

The invention provides a high-precision fixture and method for measuring the lithium plug impedance of the negative pole piece of a lithium ion battery. The fixture comprises a sealing chamber device,a lithium sheet interface flattening and fixing device, a pole spacing adjusting device, and a to-be-tested pole piece fixing device. The sealing chamber device is used to ensure that the measuring environment is free of water and oxygen. The lithium sheet interface flattening and fixing device is used to install a lithium piece reference electrode. Through a flat thread on the upper section, thesurface of a lithium piece is flattened to ensure consistent pole spacing. When the surface is flattened, good contact between the lithium piece and an electrode fixing device is ensured through large pressure. The pole spacing adjusting device adjusts the interface spacing between the reference electrode and a measured electrode according to the interface flatness of the measured electrode, so as to sure that the pole spacing between different groups is consistent. The to-be-tested pole piece fixing device uses micro-pore negative pressure to fix the tested pole piece to ensure good contactbetween a pole piece current collector and a lead. The high-precision impedance measuring method for the negative pole piece of the lithium battery can quickly evaluate the impedance of the negative electrode formula between different groups, can significantly reduce the screening time and the evaluation cost of the groups, improves the economic benefit of an enterprise, can be widely applied in application, and has a significant practical significance in production.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, and in particular relates to a fixture and method for measuring the impedance of lithium-embedded lithium-ion battery negative electrodes with high precision. Background technique [0002] After more than 20 years of development, lithium-ion batteries have a rich industrial chain and a diversified development trend of battery models. The performance of batteries can meet the needs of many industries for power supplies. At present, they have been widely used in electric vehicle power supplies, communication base station power supplies, communication tools and In the field of electric tools and other fields, the electrochemical performance of lithium-ion batteries directly affects its application fields, especially the impedance of lithium-ion batteries, which seriously affects the ambient temperature and heat preservation measures of battery applications. The impedance of lithium-ion bat...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the present invention aims to propose a fixture and method for measuring the lithium-intercalation impedance of the negative pole piece of a high-precision lithium-ion battery, so as to solve the problem of inaccurate measurement and isolation caused by the fluctuation of the reference electrode between different groups. Technical difficulties that cannot be eliminated due to membrane effects

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