Method and apparatus for detecting lithium plating, and method and apparatus for obtaining polarization proportion

Patent metadata

Field	Value
Publication number	US-2023052544-A1
Application number	US-202217976402-A
Country	US
Kind code	A1
Filing date	Oct 28, 2022
Priority date	Apr 30, 2020
Publication date	Feb 16, 2023
Grant date	—

Abstract

Example methods and apparatuses for detecting lithium plating and obtaining a polarization proportion are provided. One example method includes obtaining an open-circuit voltage of a rechargeable battery and a negative electrode open-circuit voltage of the rechargeable battery based on a state of charge of the rechargeable battery. A negative electrode polarization voltage of the rechargeable battery is obtained based on the open-circuit voltage, a terminal voltage of the rechargeable battery, and a polarization proportion of the rechargeable battery. A negative electrode voltage of the rechargeable battery is obtained based on the negative electrode open-circuit voltage and the negative electrode polarization voltage. It is determined, based on the negative electrode voltage, whether lithium plating occurs in the rechargeable battery.

First claim

1 . A method, comprising:
obtaining an open-circuit voltage of a rechargeable battery and a negative electrode open-circuit voltage of the rechargeable battery based on a state of charge of the rechargeable battery; obtaining a negative electrode polarization voltage of the rechargeable battery based on the open-circuit voltage of the rechargeable battery, a terminal voltage of the rechargeable battery, and a polarization proportion of the rechargeable battery, wherein the polarization proportion of the rechargeable battery represents a proportion that is of the negative electrode polarization voltage of the rechargeable battery to a polarization voltage of the rechargeable battery and that is obtained when the rechargeable battery is at a lithium plating critical point; obtaining a negative electrode voltage of the rechargeable battery based on the negative electrode open-circuit voltage of the rechargeable battery and the negative electrode polarization voltage of the rechargeable battery; and determining, based on the negative electrode voltage of the rechargeable battery, whether lithium plating occurs in the rechargeable battery.

2 . The method according to claim 1 , wherein the determining, based on the negative electrode voltage of the rechargeable battery, whether lithium plating occurs in the rechargeable battery comprises:
when the negative electrode voltage of the rechargeable battery is less than a reference voltage threshold, determining that lithium plating occurs in the rechargeable battery.

3 . The method according to claim 1 , wherein the obtaining a negative electrode polarization voltage of the rechargeable battery based on the open-circuit voltage of the rechargeable battery, a terminal voltage of the rechargeable battery, and a polarization proportion of the rechargeable battery comprises:
obtaining the polarization voltage of the rechargeable battery based on the open-circuit voltage of the rechargeable battery, the terminal voltage of the rechargeable battery, and a first reference relationship, wherein the first reference relationship is a relationship among the open-circuit voltage of the rechargeable battery, the terminal voltage of the rechargeable battery, and the polarization voltage of the rechargeable battery; and obtaining the negative electrode polarization voltage of the rechargeable battery based on the polarization voltage of the rechargeable battery and the polarization proportion of the rechargeable battery.

4 . The method according to claim 1 , wherein before the obtaining a negative electrode polarization voltage of the rechargeable battery based on the open-circuit voltage of the rechargeable battery, a terminal voltage of the rechargeable battery, and a polarization proportion of the rechargeable battery, the method further comprises:
obtaining a polarization voltage of a first reference battery when the first reference battery is charged by using a target charging current and is at the lithium plating critical point; obtaining a negative electrode polarization voltage of the first reference battery when the first reference battery is charged by using the target charging current and is at the lithium plating critical point; and obtaining the polarization proportion of the rechargeable battery based on the negative electrode polarization voltage of the first reference battery and the polarization voltage of the first reference battery.

5 . The method according to claim 4 , wherein the obtaining a polarization voltage of a first reference battery when the first reference battery is charged by using a target charging current and is at a lithium plating critical point comprises:
obtaining a state of charge of the first reference battery and a terminal voltage of the first reference battery when the first reference battery is charged by using the target charging current and is at the lithium plating critical point; querying a correspondence between an open-circuit voltage of the first reference battery and the state of charge of the first reference battery based on the state of charge of the first reference battery to obtain the open-circuit voltage of the first reference battery; and obtaining the polarization voltage of the first reference battery based on the open-circuit voltage of the first reference battery, the terminal voltage of the first reference battery, and a second reference relationship, wherein the second reference relationship is a relationship among the open-circuit voltage of the first reference battery, the terminal voltage of the first reference battery, and the of the first reference battery.

6 . The method according to claim 4 , wherein the obtaining a negative electrode polarization voltage of the first reference battery when the first reference battery is charged by using the target charging current and is at the lithium plating critical point comprises:
obtaining the state of charge of the first reference battery and a negative electrode voltage of the first reference battery when the first reference battery is charged by using the target charging current and is at the lithium plating critical point; querying a correspondence between a negative electrode open-circuit voltage of the first reference battery and the state of charge of the first reference battery based on the state of charge of the first reference battery to obtain the negative electrode open-circuit voltage of the first reference battery; and obtaining the negative electrode polarization voltage of the first reference battery based on the negative electrode open-circuit voltage of the first reference battery, the negative electrode voltage of the first reference battery, and a third reference relationship, wherein the third reference relationship is a relationship among the negative electrode voltage of the first reference battery, the negative electrode open-circuit voltage of the first reference battery, and the negative electrode polarization voltage of the first reference battery.

7 . The method according to claim 1 , wherein the obtaining an open-circuit voltage of the rechargeable battery and a negative electrode open-circuit voltage of the rechargeable battery based on a state of charge of the rechargeable battery comprises:
querying a correspondence between the open-circuit voltage of the rechargeable battery and the state of charge of the rechargeable battery based on the state of charge of the rechargeable battery to obtain the open-circuit voltage of the rechargeable battery; and querying a correspondence between the negative electrode open-circuit voltage of the rechargeable battery and the state of charge of the rechargeable battery based on the state of charge of the rechargeable battery to obtain the negative electrode open-circuit voltage of the rechargeable battery.

8 . The method according to claim 1 , wherein before the obtaining an open-circuit voltage of the rechargeable battery and a negative electrode open-circuit voltage of the rechargeable battery based on a state of charge of the rechargeable battery, the method further comprises:
obtaining a correspondence between an open-circuit voltage of a first reference battery and a remaining capacity of the first reference battery based on a charging and discharging test performed on the first reference battery, and obtaining the correspondence between the open-circuit voltage of the rechargeable battery and the state of charge of the rechargeable battery based on the correspondence between the open-circuit voltage of the first reference battery and the remaining capacity of the first reference battery; or obtaining a correspondence between an open-circuit voltage of a second reference battery and a remaining capacity of the second reference battery bas

Assignees

• Huawei Tech Co Ltd

Inventors

• Yuan Shifei
• Liu Bingxiao
• Wu Zhiwei

Classifications

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• G01R31/378

  specially adapted for the type of battery or accumulator · CPC title

• G01R31/392 Primary

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• G01R31/388

  involving voltage measurements · CPC title

• H01M10/44

  Methods for charging or discharging (circuits for charging H02J7/00) · CPC title