CN-115939534-B - Lithium ion battery lithium separation nondestructive diagnosis method

CN115939534BCN 115939534 BCN115939534 BCN 115939534BCN-115939534-B

Abstract

The invention relates to the technical field of batteries, in particular to a lithium ion battery lithium analysis nondestructive diagnosis method which comprises the following steps of S1, analyzing characteristic parameters of an electrochemical curve of a battery, S2, if the characteristic parameters of the electrochemical curve are smaller than zero, carrying out the next step, and returning to the previous step, S3, placing a pressure sensing film on a pressure loading device, placing the battery on the pressure sensing film, applying set pre-pressure to the battery by using the pressure loading device, S4, carrying out cyclic charge and discharge on the battery within set time, S5, determining a lithium analysis area by using a display device in communication connection with the pressure sensing film, and S6, carrying out nondestructive scanning on the lithium analysis area by using a neutron Bragg edge imaging characterization method to obtain Bragg Bian Yanshe spectrum. The invention can analyze the lithium-separating area and the lithium-separating content of the lithium ion battery.

Inventors

YANG LUFENG
CHEN JIE
WANG SHENGXIANG
TAN ZHIJIAN

Assignees

散裂中子源科学中心
中国科学院高能物理研究所

Dates

Publication Date: 20260512
Application Date: 20221124

Claims (8)

1. The lithium ion battery lithium separation nondestructive diagnosis method is characterized by comprising the following steps: s1, analyzing characteristic parameters of an electrochemical curve of a battery; s2, if the characteristic parameters of the electrochemical curve are smaller than zero, performing the next step, and if not, returning to the previous step; S3, placing a pressure sensing film on a pressure loading device, placing the battery on the pressure sensing film, and applying set pre-pressure to the battery by using the pressure loading device; S4, circularly charging and discharging the battery in a set time; s5, determining a lithium precipitation area by using a display device in communication connection with the pressure sensing membrane; s6, carrying out nondestructive scanning on the lithium separation region by using a neutron Bragg edge imaging characterization method to obtain a Bragg Bian Yanshe spectrum; in the step S5, the display device displays colors of different shades according to the pressed condition of the pressure sensing film.
2. The method according to claim 1, wherein in the step S1, the electrochemical curve is a voltage fluctuation curve of the battery.
3. The lithium ion battery lithium-ion analysis nondestructive diagnosis method according to claim 1, wherein in the step S3, the pre-pressure is set according to the type and the volume of the battery.
4. The method according to claim 1, wherein in the step S3, a first pressing pad is disposed on an upper end surface of the battery, and a second pressing pad is disposed on a lower end surface of the pressure sensing membrane.
5. The lithium ion battery lithium-ion separation nondestructive diagnosis method according to claim 4, wherein an area of a lower end face of the first pressure pad is larger than an area of an upper end face of the battery.
6. The lithium ion battery lithium-ion separation nondestructive diagnosis method according to claim 4, wherein an area of an upper end face of the second pressure pad is larger than an area of a lower end face of the battery.
7. The lithium ion battery lithium-ion battery nondestructive diagnosis method according to claim 1, wherein in the step S3, a pressure display is provided on the pressure loading device, and the pressure display is used for displaying the value of the pre-pressure.
8. The method according to claim 1, wherein in step S5, the lithium-ion battery is marked by scribing in the lithium-ion battery area.

Description

Lithium ion battery lithium separation nondestructive diagnosis method Technical Field The invention relates to the technical field of batteries, in particular to a lithium ion battery lithium-precipitation nondestructive diagnosis method. Background Lithium ion batteries are used in large numbers in production and life. When the lithium ion battery is charged, li+ is released from the positive electrode and is inserted into the negative electrode, but when abnormal conditions such as insufficient lithium insertion space of the negative electrode, too large resistance of the Li+ inserted into the negative electrode, too fast release of Li+ from the positive electrode but incapacity of equally inserting into the negative electrode occur, li+ which cannot be inserted into the negative electrode can only obtain electrons on the surface of the negative electrode, so that silvery white metal lithium simple substance is formed, and lithium precipitation occurs. The lithium precipitation not only reduces the battery performance and shortens the cycle life greatly, but also limits the quick charge capacity of the battery, and possibly causes disasters such as combustion, explosion and the like. However, in the prior art, it is only possible to determine whether a lithium precipitation phenomenon occurs, but it is impossible to analyze a lithium precipitation area and a lithium precipitation content of a lithium ion battery, so that further analysis and optimization of the lithium ion battery are impossible. Therefore, there is a need for a lithium ion battery lithium-precipitation non-destructive diagnostic method to solve the above-mentioned problems. Disclosure of Invention The invention aims to provide a lithium ion battery lithium-precipitation nondestructive diagnosis method which can analyze a lithium-precipitation area and the lithium-precipitation content of a lithium ion battery. To achieve the purpose, the invention adopts the following technical scheme: The lithium ion battery lithium separation nondestructive diagnosis method comprises the following steps: s1, analyzing characteristic parameters of an electrochemical curve of a battery; s2, if the characteristic parameters of the electrochemical curve are smaller than zero, performing the next step, and if not, returning to the previous step; S3, placing a pressure sensing film on a pressure loading device, placing the battery on the pressure sensing film, and applying set pre-pressure to the battery by using the pressure loading device; S4, circularly charging and discharging the battery in a set time; s5, determining a lithium precipitation area by using a display device in communication connection with the pressure sensing membrane; s6, carrying out nondestructive scanning on the lithium separation region by using a neutron Bragg edge imaging characterization method to obtain a Bragg Bian Yanshe spectrum. Further, in the step S1, the electrochemical curve is a voltage fluctuation curve of the battery. Further, in the step S3, the pre-pressure is set according to the type and the volume of the battery. Further, in the step S3, a first pressing pad is disposed on an upper end face of the battery, and a second pressing pad is disposed on a lower end face of the pressure sensing film. Further, the area of the lower end surface of the first pressing pad is larger than the area of the upper end surface of the battery. Further, the area of the upper end surface of the second pressing pad is larger than the area of the lower end surface of the battery. Further, in the step S3, a pressure display is provided on the pressure loading device, and the pressure display is used for displaying the value of the pre-pressure. Further, in the step S5, the display device displays different colors according to the pressed condition of the pressure sensing film. Further, in the step S5, a scribe mark is performed in the lithium analysis region. The invention has the beneficial effects that: According to the lithium ion battery lithium-ion analysis nondestructive diagnosis method provided by the invention, whether a lithium-ion analysis phenomenon exists is judged by analyzing characteristic parameters of a chemical curve of a battery, if the lithium-ion battery is in existence, the battery is placed on a pressure sensing film of a pressure loading device, the pressure loading device is used for applying set pre-pressure to the battery, the battery is circularly charged and discharged in set time, and as the lithium-ion analysis position is expanded relative to the lithium-ion-analysis-free position, the forces applied to the pressure sensing film by different positions of the battery are different in the charging and discharging processes, the lithium-ion-analysis region is determined by a display device in communication connection with the pressure sensing film, and then the lithium-ion battery is subjected to nondestructive scanning by utilizing a neutron Bragg edge ima