Battery temperature estimation method and apparatus, electronic device, and storage medium

A battery temperature estimation apparatus, comprising:

• a fitting module, configured to fit, when a battery is in an offline state, a first function relationship according to corresponding admittances of the battery at different test temperatures;
• and
• a first determination module, configured to obtain a temperature distribution model of the battery according to the shape and the size of the battery, and determine a second function relationship corresponding to internal temperatures and a surface temperature by combining with the first function relationship, the second function relationship being used for estimating the internal temperature of the battery by combining with the surface temperature and the admittances of the battery,
• wherein the fitting module further comprises:
• a first determination sub-module, configured to determine a feature test frequency when the battery is in the offline state, wherein the feature test frequency is within a target frequency range, and in the target frequency range, impedance of the battery does not change with a state of charge of the battery,
• wherein the first determination sub-module is specifically configured to:
• perform electrochemical impedance spectroscopy testing on the battery in a preset frequency range in different states of charge;
• determine the target frequency range from the preset frequency range according to a result of the testing;
• test response values of electrochemical impedance spectroscopy of the battery in a preset state of charge at different temperatures, and convert the response values into the corresponding admittances;
• and
• determine a frequency at which real parts of the admittances change most with temperatures in the target frequency range as the feature test frequency.

An electronic device, comprising:

• a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor, when executing the program, implementing a battery temperature estimation method to perform:
• fitting, when a battery is in an offline state, a first function relationship according to corresponding admittances of the battery at different test temperatures;
• and
• obtaining a temperature distribution model of the battery according to the shape and the size of the battery, and determining a second function relationship corresponding to internal temperatures and a surface temperature by combining with the first function relationship, the second function relationship being used for estimating the internal temperature of the battery by using the surface temperature and the admittances of the battery,
• wherein the fitting a first function relationship according to corresponding admittances of the battery at different test temperatures further includes:
• determining a feature test frequency when the battery is in the offline state, wherein the feature test frequency is within a target frequency range, and in the target frequency range, impedance of the battery does not change with a state of charge of the battery,
• wherein the determining a feature test frequency further includes:
• performing electrochemical impedance spectroscopy testing on the battery in a preset frequency range in different states of charge;
• determining the target frequency range from the preset frequency range according to a result of the testing;
• testing response values of electrochemical impedance spectroscopy of the battery in a preset state of charge at different temperatures, and converting the response values into the corresponding admittances;
• and
• determining a frequency at which real parts of the admittances change most with temperatures in the target frequency range as the feature test frequency.