CN-121978550-A - Battery short-circuit degree calibration method and device, terminal equipment and storage medium

CN121978550ACN 121978550 ACN121978550 ACN 121978550ACN-121978550-A

Abstract

The application relates to the technical field of new energy batteries, in particular to a battery short-circuit degree calibration method, a device, terminal equipment and a storage medium, wherein the method comprises the steps of performing controllable external short-circuit tests of a plurality of preset resistance values on a target battery sample in an adiabatic environment, synchronously collecting test data under each preset resistance value, and establishing a calibration database according to the test data; in the same adiabatic environment, performing needling test on a target battery sample, synchronously collecting battery voltage and adiabatic temperature rise data in the needling process, calculating real-time heat generation power of the battery in the needling process based on the adiabatic temperature rise data, matching and inverting the real-time heat generation power with a calibration database to obtain an equivalent external short circuit resistance value corresponding to the same heat generation power generated at each moment in the needling process, and generating an equivalent resistance change curve with time according to the moment and the corresponding equivalent external short circuit resistance value. The quantitative evaluation of the short circuit degree in the battery is realized.

Inventors

GAO ZHE
Bai Zehui
CAO KAI
CHEN WEI

Assignees

溧阳中科海钠科技有限责任公司

Dates

Publication Date: 20260505
Application Date: 20260327

Claims (10)

1. The battery short-circuit degree calibration method is characterized by comprising the following steps of: In an adiabatic environment, carrying out controllable external short-circuit tests of a plurality of preset resistance values on a target battery sample, synchronously collecting test data under each preset resistance value, and establishing a calibration database according to the test data; In the same adiabatic environment, performing needling test on the target battery sample, and synchronously collecting battery voltage and adiabatic temperature rise data in the needling process; calculating real-time heat generation power of the target battery sample in the needling process based on the adiabatic temperature rise data; and matching and inverting the real-time heat generation power with the calibration database to obtain an equivalent external short circuit resistance value corresponding to the same heat generation power generated at each moment in the needling process, and generating an equivalent resistance change curve along with time according to the moment and the corresponding equivalent external short circuit resistance value.
2. The method of claim 1, wherein the adiabatic environment is provided by an accelerated calorimeter.
3. The method of claim 1, wherein the test data comprises battery voltage, current, and adiabatic temperature rise data.
4. The method for calibrating a battery short-circuit degree according to claim 1, wherein the calculating the real-time heat generation power of the battery during the needling process comprises: Deriving the adiabatic temperature rise data to obtain an instantaneous temperature rise rate, and calculating the real-time heat generation power based on the instantaneous temperature rise rate; the calculation expression of the real-time heat generation power is as follows: P Needle (t) = C batt (dT Needle (t)/dt); Wherein P Needle (t) is the real-time heat generation power, C batt is the overall heat capacity of the battery, and dT Needle (t)/dT is the instantaneous temperature rise rate.
5. The method for calibrating the short-circuit degree of a battery according to claim 2, wherein the step of establishing a calibration database according to the test data comprises the steps of: Calculating theoretical heat generation power and a heat capacity model through Joule's law to calculate actual heat generation power; and calculating a difference value between the theoretical heat-generating power and the actual heat-generating power, and if the difference value is smaller than a preset threshold value, taking the actual heat-generating power into a calibration database as effective data.
6. The method for calibrating the short-circuit degree of the battery according to claim 1, wherein the matching and inverting the real-time generated heat power with the calibration database to obtain the equivalent external short-circuit resistance value corresponding to the same generated heat power generated at each moment in the needling process comprises the following steps: and searching in the calibration database at any moment in the needling process to obtain an external short circuit resistance value which can generate the same heat generating power as the real-time heat generating power under the battery voltage at the moment, wherein the external short circuit resistance value is an equivalent external short circuit resistance value.
7. The battery short-circuit degree calibration method according to claim 1, further comprising: When no completely matched data item exists in the calibration database, an interpolation algorithm is adopted to construct a functional relation between the heat generating power and the external short circuit resistance based on the heat generating power-voltage relation under the adjacent resistance condition, and the equivalent external short circuit resistance value is obtained.
8. A battery short-circuit degree calibration device, comprising: the database establishing module is used for carrying out controllable external short-circuit tests of a plurality of preset resistance values on a target battery sample in an adiabatic environment, synchronously collecting test data under each preset resistance value, and establishing a calibration database according to the test data; the adiabatic temperature rise data acquisition module is used for performing needling test on the target battery sample in the same adiabatic environment, and synchronously acquiring battery voltage and adiabatic temperature rise data in the needling process; The calculation module is used for calculating the real-time heat generation power of the battery in the needling process based on the adiabatic temperature rise data; And the calibration module is used for matching and inverting the real-time heat generation power with the calibration database to obtain an equivalent external short circuit resistance value corresponding to the same heat generation power generated at each moment in the needling process, and generating an equivalent resistance time-varying curve according to the moment and the corresponding equivalent external short circuit resistance value.
9. A terminal device, characterized in that it comprises a processor and a memory, the memory storing a computer program, the processor being adapted to execute the computer program to implement the battery short-circuit degree calibration method according to any one of claims 1-7.
10. A readable storage medium, characterized in that it stores a computer program which, when executed on a processor, implements the battery short-circuit degree calibration method according to any one of claims 1-7.

Description

Battery short-circuit degree calibration method and device, terminal equipment and storage medium Technical Field The application relates to the technical field of new energy batteries, in particular to a battery short-circuit degree calibration method, a device, terminal equipment and a storage medium. Background The needling test is one of the most stringent, direct means of assessing sodium ion battery safety, which triggers thermal runaway by simulating an internal short circuit. However, the conventional needling test is only a qualitative evaluation method of "pass/fail" (e.g., observe whether fire, explosion occur). The test results are seriously dependent on specific conditions such as needling position, speed, needle material and the like, have poor repeatability and cannot provide any quantitative parameters. The core technical dilemma faced by the person skilled in the art is how to obtain a quantitative characteristic parameter of the transient, severe, non-repeatable process of the intra-needle short. Due to the lack of the parameters, the battery management system cannot set an accurate internal short circuit early warning threshold according to experimental data, a simulation engineer lacks critical boundary condition input when building a thermal runaway model, and battery designers are difficult to accurately compare the safety performance of different design schemes. In the prior art, the internal short circuit is simulated by external heating or external short circuit, but the intrinsic difference problem of the real needle internal short circuit in terms of heat distribution locality, process dynamic property and triggering chemical reaction cannot be solved, so that an equivalent quantitative index cannot be provided. Disclosure of Invention In view of the above, embodiments of the present application provide a method, an apparatus, a terminal device, and a storage medium for calibrating a battery short-circuit degree, which can effectively solve the problem that an equivalent quantization index cannot be provided. In a first aspect, an embodiment of the present application provides a method for calibrating a short-circuit degree of a battery, including: In an adiabatic environment, carrying out controllable external short-circuit tests of a plurality of preset resistance values on a target battery sample, synchronously collecting test data under each preset resistance value, and establishing a calibration database according to the test data; In the same adiabatic environment, performing needling test on the target battery sample, and synchronously collecting battery voltage and adiabatic temperature rise data in the needling process; Calculating the real-time heat generation power of the battery in the needling process based on the adiabatic temperature rise data; and matching and inverting the real-time heat generation power with the calibration database to obtain an equivalent external short circuit resistance value corresponding to the same heat generation power generated at each moment in the needling process, and generating an equivalent resistance change curve along with time according to the moment and the corresponding equivalent external short circuit resistance value. In some embodiments, the adiabatic environment is provided by an accelerated calorimeter and ambient heat loss is ignored. In some embodiments, the test data includes battery voltage, current, and adiabatic temperature rise data. In some embodiments, the calculating the real-time heat generation power of the battery during the needling process includes: Deriving the adiabatic temperature rise data to obtain an instantaneous temperature rise rate, and calculating the real-time heat generation power based on the instantaneous temperature rise rate; the calculation expression of the real-time heat generation power is as follows: P Needle (t) = Cbatt(dT Needle (t)/dt); Wherein P Needle (t) is the real-time heat generation power, C batt is the overall heat capacity of the battery, and dT Needle (t)/dT is the instantaneous temperature rise rate. In some embodiments, the building a calibration data base from the test data includes: Calculating theoretical heat generation power and a heat capacity model through Joule's law to calculate actual heat generation power; and calculating a difference value between the theoretical heat-generating power and the actual heat-generating power, and if the difference value is smaller than a preset threshold value, taking the actual heat-generating power into a calibration database as effective data. In some embodiments, the matching and inverting the real-time generated heat power with the calibration database to obtain an equivalent external short-circuit resistance value corresponding to the same generated heat power generated at each moment in the needling process includes: And searching in the calibration database at any moment in the needling process to obtain an external sh