Detecting method for judging influence of diaphragm material on battery performance

Abstract

The invention discloses a detecting method for judging influence of diaphragm material on battery performance, which includes steps of S1, preparing an experiment battery, and taking out a pair of positive pole piece and a negative pole piece which have consistent weight, preparing to be an experimental battery; S2, carrying out the formation of the experimental battery and 0.3C charge / 1C discharge partial volume circulation, and then fully charging the experimental battery; S3, measuring an electrochemistry impedance spectroscopy of the experimental battery to obtain impedance spectrogram-Nyquist curve; S4, after placing the experimental battery for a certain time, fully charging the experimental battery, and repeating the measurement process of S3; S5, fitting impedance spectrogram of experimental battery; and analyzing to obtain battery ohm inner resistance Rs and ohm inner resistance Rf of the battery inner solid- electrolyte interface film (SEI); S6, performing 0.3C charge / 1C discharge partial volume circulation on the placed battery; calculating the capacity retention ratio before and after placing the battery at high temperature. The detecting method has the beneficial effects that the application range is wide, and the high-temperature placing performance of the battery can be rapidly judged.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and relates to a detection method for judging the influence of diaphragm materials on battery performance. Background technique [0002] At present, lithium-ion batteries, as the preferred power battery for pure electric vehicles, have been produced and used on a large scale. Lithium-ion battery diaphragms have been industrialized in China, not only can produce various dry and wet diaphragms, but also can produce diaphragms coated with ceramics on one or both sides. In the battery, the separator plays the role of isolating the positive and negative electron paths and providing the lithium ion path, which not only affects the electrochemical performance of the battery, but also has a particularly critical impact on the safety of the battery. When designing power lithium-ion batteries, we not only require lithium-ion batteries to have a certain large porosity and be as light and thin...

AI Technical Summary

Problems solved by technology

Because the separator does not participate in the electrochemical reaction, it is difficult for us to judge how the separator affects the electrochemical performance of the battery in the selection of the separator.