公开(公告)号：US20240361394A1

公开(公告)日：2024-10-31

申请号：US18650083

申请日：2024-04-30

Applicant: BEIJING UNIVERSITY OF TECHNOLOGY

Inventor： Yan Lyu ,  Jie Gao ,  Xuan Liu ,  Bin Wu ,  Cunfu He

IPC: G01R31/387 ,  G01N29/07 ,  G01N29/24 ,  G01R31/367

CPC classification number: G01R31/387 ,  G01N29/07 ,  G01N29/2437 ,  G01R31/367 ,  G01N2291/023

Abstract: The present invention discloses a method for in-situ detection of the state of charge (SOC) of pouch-type lithium-ion batteries using ultrasonic guided waves. The invention involves attaching two circular piezoelectric patches symmetrically at a fixed distance from each other on the surface of the lithium-ion battery using a coupling agent. A function generator is controlled to produce a Hanning-window-modulated five-cycle sine signal to excite the circular piezoelectric patch located on the left side of the battery, generating ultrasonic guided waves within the battery. These waves are then received by the circular piezoelectric patch located on the right side of the battery. The received guided wave signal is processed to extract the time-domain characteristic parameters of the wave (transit time). Based on the correspondence between the guided wave characteristic parameters (transit time) and the state of charge, the method enables the detection of the SOC of the pouch-type lithium-ion battery. The invention employs a pair of circular piezoelectric patches in a one-actuation, one-reception manner for the detection of lithium-ion batteries, achieving in-situ detection of the SOC of pouch-type lithium-ion batteries without the need to record external parameters such as current and voltage.

公开(公告)号：US20240280643A1

公开(公告)日：2024-08-22

申请号：US18650011

申请日：2024-04-29

Applicant: BEIJING UNIVERSITY OF TECHNOLOGY

Inventor： Yan Lyu ,  Jie Gao ,  Xuan Liu ,  Bin Wu ,  Cunfu He

IPC: G01R31/387 ,  G01R31/367 ,  G01R31/378

CPC classification number: G01R31/387 ,  G01R31/367 ,  G01R31/378

Abstract: The present invention discloses a method for characterizing the State of Charge (SOC) of lithium-ion batteries using an ultrasonic reflection coefficient, which employs a water immersion ultrasonic detection method for measuring the reflection coefficient angular spectrum of lithium-ion batteries. This invention pertains to the field of non-destructive testing technology. A pouch-type lithium-ion battery can be regarded as a laminated structure composed of multiple materials, and when the State of Charge (SOC) of the lithium-ion battery varies, its reflection coefficient changes accordingly. The invention acquires the reflection coefficient angular spectrum of lithium-ion batteries at different SOCs through ultrasonic water immersion detection, establishes a mapping relationship between the angular spectrum and the SOC of the lithium-ion battery, and uses the distance between the two peak values of the angular spectrum to characterize the SOC of the lithium-ion battery. The invention enables non-destructive characterization of the SOC of lithium-ion batteries and allows for localized SOC measurement of the batteries.