Three-electrode measurement based online monitoring method for electrochemical properties of positive electrode and negative electrode of lithium battery

Abstract

The invention discloses a three-electrode measurement based online monitoring method for electrochemical properties of a positive electrode and a negative electrode of a lithium battery. The method is characterized by comprising steps of 1, selecting appropriate material for assembling a three-electrode measurement device; 2, adopting a charge / discharge testing instrument to connect with the positive electrode and the negative electrode of a three-electrode lithium ion battery separately and performing charge / discharge testing; 3, performing online synchronous monitoring on positive voltage and negative voltage of the lithium ion battery; 4, performing online synchronous electrochemical impedance testing on the lithium ion battery and utilizing an impedance spectroscopy testing instrument to measure the positive electrode and the negative electrode and the electrochemical impedance spectroscopy of the whole battery after the battery is charged or discharged until a stable state is reached. The invention has beneficial effects that the novel testing method capable of collecting electrochemical information of the whole battery, the positive electrode and the negative electrode at the same time is provided and a defect that electrochemical information in the battery cannot be measured accurately by using a current traditional two-electrode testing method for commercial batteries is made up.

Description

technical field [0001] The invention relates to an online monitoring method for the electrochemical characteristics of positive and negative electrodes of a lithium battery based on three-electrode measurement, and belongs to the technical field of lithium battery testing. Background technique [0002] With the rise of electric vehicles in recent years, lithium batteries as an energy source are very important components in the electric vehicle system, especially for the efficiency and safety of electric vehicles, lithium batteries are even more crucial. However, battery aging is still a thorny problem in the commercial application of lithium batteries, and the aging process of batteries is also quite complicated. The loss of battery energy and the weakening of efficiency are not caused by a single factor, but by many different processes, such as: depth of discharge, charge and discharge speed, operating temperature, external pressure, and the interaction between various fact...

AI Technical Summary

Problems solved by technology

[0008] But what the above patents mentioned are all new test devices, and there are still some shortcomings

For example 1, these devices cannot be reused. On the one hand, materials are wasted. On the other hand, for experimental research, the assembly consistency of each experiment cannot be guaranteed.

2. These patents mainly lie in the innovation of the device, and the method of synchronously monitoring the electrochemical characteristics of the positive and negative electrodes inside the battery has not been reported yet.

Images