Method and device for monitoring state of charge and state of health of lithium-ion battery

Patent metadata

Field	Value
Publication number	US-2019049518-A1
Application number	US-201716083318-A
Country	US
Kind code	A1
Filing date	Aug 8, 2017
Priority date	Nov 21, 2016
Publication date	Feb 14, 2019
Grant date	—

Abstract

The present invention discloses a method and device for monitoring state of charge and state of health of a battery, and relates to the technical field of battery. The method comprises: firstly, passing ultrasonic waves through a lithium-ion battery in different SOCs at different charging and discharging currents to obtain acoustic parameters, and then establishing respective corresponding relationships between the acoustic parameters and the lithium-ion battery SOC and SOH; and secondly, monitoring the acoustic parameters of a lithium-ion battery, and then estimating SOC and SOH of the lithium-ion battery by combining the monitored acoustic parameters with the respective corresponding relationships between the acoustic parameters and the lithium-ion battery SOC and SOH. The invention further provides a device implementing the above method. The method and device can monitor the battery SOC and SOH in a brand new way different from the electricity parameter measurement. The method can effectively monitor SOC and SOH of lithium-ion batteries of various types and shapes and thus has a good application prospect.

First claim

1 . A method for monitoring state of charge (SOC) and state of health (SOH) of a lithium-ion battery, comprising:
firstly, passing ultrasonic waves through a lithium-ion battery in different SOCs at different charging and discharging currents to obtain acoustic parameters, and then establishing respective corresponding relationships between the acoustic parameters and the lithium-ion battery SOC and SOH; and secondly, monitoring the acoustic parameters of a lithium-ion battery, and then estimating SOC and SOH of the lithium-ion battery by combining the monitored acoustic parameters with the respective corresponding relationships between the acoustic parameters and the lithium-ion battery SOC and SOH, wherein the acoustic parameters include an amplitude attenuation degree, a flight time and an acoustic fingerprint of the ultrasonic wave passing through the lithium-ion battery, the flight time refers to the time it takes for the ultrasonic wave to travel from an ultrasonic signal source to an ultrasonic signal receiver, with the ultrasonic signal source and the ultrasonic signal receiver connected to the same lithium-ion battery, and the acoustic fingerprint refers to a waveform of the ultrasonic wave passing through the lithium ion battery.

2 . The method for monitoring SOC and SOH of a lithium-ion battery of claim 1 , comprising:
firstly, passing ultrasonic waves with a specific frequency and amplitude through a lithium-ion battery in different SOCs at different charging and discharging currents to obtain respective amplitude attenuation degrees of the ultrasonic waves with the specific frequency and amplitude, and then establishing respective corresponding relationships between the amplitude attenuation degree and the lithium-ion battery SOC at different charging and discharging currents to obtain respective gauging maps; and secondly, during use of a lithium-ion battery, monitoring respective amplitude attenuation degrees of the ultrasonic waves with the specific frequency and amplitude passing through the lithium-ion battery at different charging and discharging currents, obtaining respective corresponding relationships between the amplitude attenuation degree of the ultrasonic waves with the specific frequency and amplitude and the SOC according to the gauging maps, and then estimating SOC of the lithium-ion battery.

3 . The method for monitoring SOC and SOH of a lithium-ion battery of claim 1 , comprising:
firstly, passing ultrasonic waves through a lithium-ion battery in different SOCs at different charging and discharging currents to obtain respective flight times, and then establishing respective corresponding relationships between the flight time and the lithium-ion battery SOC at different charging and discharging currents to obtain respective gauging maps; and secondly, during use of a lithium-ion battery, monitoring respective flight times of the ultrasonic waves passing through the lithium-ion battery at different charging and discharging currents, obtaining respective corresponding relationships between the flight time and the lithium-ion battery SOC at different charging and discharging currents according to the gauging maps, and then estimating SOC of the lithium-ion battery.

4 . The method for monitoring SOC and SOH of a lithium-ion battery of claim 1 , comprising:
firstly, passing ultrasonic waves with a specific frequency and amplitude through a healthy lithium-ion battery in different SOCs at different charging and discharging currents to obtain respective amplitude attenuation degrees of the ultrasonic waves with the specific frequency and amplitude, and then to obtain respective amplitudes of the ultrasonic waves passing through the healthy lithium-ion battery at different charging and discharging currents; and secondly, passing ultrasonic waves with the specific frequency and amplitude through a lithium-ion battery in different SOCs at different charging and discharging currents to monitor amplitudes of the ultrasonic waves with the specific frequency and amplitude passing through the lithium-ion battery, so that if the monitored amplitudes decrease abnormally compared to that of the healthy lithium-ion battery, it is determined that the lithium-ion battery SOH is poor.

5 . The method for monitoring SOC and SOH of a lithium-ion battery of claim 1 , comprising:
firstly, passing ultrasonic waves through a healthy lithium-ion battery in different SOCs at different charging and discharging currents to obtain respective flight times of a specific wave peak in the ultrasonic waves, and then to obtain respective flight times of the specific wave peak passing through the healthy lithium-ion battery at different charging and discharging currents; and secondly, passing ultrasonic waves through a lithium-ion battery in different SOCs at different charging and discharging currents to monitor respective flight times of the specific wave peak passing through the lithium-ion battery, so that if the monitored flight times increase abnormally compared to that of the healthy lithium-ion battery, it is determined that the lithium-ion battery SOH is poor.

6 . The method for monitoring SOC and SOH of a lithium-ion battery of claim 1 , comprising:
firstly, passing ultrasonic waves through a healthy lithium-ion battery in different SOCs at different charging and discharging currents, and recording ultrasonic signals passing through the lithium-ion battery to obtain reference acoustic fingerprints; and secondly, passing ultrasonic waves through a lithium-ion battery in different SOCs at different charging and discharging currents to obtain detection acoustic fingerprints, so that if the difference between the detection acoustic fingerprint and the reference acoustic fingerprint exceeds a set value, it is determined that the lithium-ion battery SOH is poor.

7 . A device for implementing the method according to claim 1 , comprising an ultrasonic signal source and an ultrasonic signal receiver, in which the ultrasonic signal source and the ultrasonic signal receiver are respectively located on both sides of a lithium-ion battery to be monitored, the ultrasonic signal source is used for emitting ultrasonic waves, and the ultrasonic signal receiver is used for receiving and recording the amplitude, flight time, and acoustic fingerprint of the ultrasonic waves.

Assignees

• Univ Huazhong Science Tech

Inventors

• Shen Yue
• Deng Zhe
• Huang Yunhui

Classifications

• G01N29/4427

  with stored values, e.g. threshold values · CPC title

• G01N2291/025

  Change of phase or condition · CPC title

• G01N29/11

  by measuring attenuation of acoustic waves · CPC title

• G01N29/12

  by measuring frequency or resonance of acoustic waves {(measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00)} · CPC title

• G01N29/07

  by measuring propagation velocity or propagation time of acoustic waves · CPC title