Acoustic Response Characteristics of Lithium Cobaltate/Graphite Battery during Cycling

Abstract

Lithium-ion batteries (LIB) have become an essential part of various advanced energy storage products due to their excellent performance, but research on battery degradation is always challenging. The technology of using ultrasound to characterize the state of LIBs has unique advantages compared with other non-destructive testing methods. However, there have only been a few studies on the analysis of battery cycle performance through acoustic response results. In this paper, from the perspective of electrochemical-acoustic field coupling, the ultrasonic count is introduced to characterize the battery state. The acoustic response characteristics of the LIB in the cycling are analyzed combined with the conventional acoustic metrics. Based on the continuous fatigue damage model, the acoustic count can infer partial change evolution of the overall effective Young’s modulus of the battery. This study shows that the characterization of the battery state can provide further thinking for the mechanical evolution of the batteries.

Quantitative Ultrasound Spectroscopy for Screening Cylindrical Lithium‐Ion Batteries for Second‐Life Applications

“…These characteristics have led to the consideration of graphite intercalation mechanics as the main contributor to the ultrasonic response of the battery [75] . The changes in graphite stiffness alter its acoustic impedance, affecting the mismatch of acoustic impedance at certain interfaces (“Cu | C”, “C | separator”, “separator | C” and “C | Cu”), and thus influencing how ultrasound scatters across these interfaces [41,62] . Our results show that MBf, in particular, is affected by these changes as it tracks the charging and discharging (Figure 2).…”

“…[36][37][38][39] In addition, since ultrasound wave propagation is directly influenced by changes in the mechanical properties within the specimens tested, it can give insight into a battery's internal state. [40,41] Ultrasound was introduced for SOH monitoring of LIBs in Ref. [42], who observed a decrease in the amplitude of an ultrasound transmission signal when comparing the cycled state to the original battery state.…”

“…The versatility and relatively low cost of ultrasound equipment compared to other NDE techniques has stimulated research using various acoustic approaches for SOC and SOH estimation purposes [36–39] . In addition, since ultrasound wave propagation is directly influenced by changes in the mechanical properties within the specimens tested, it can give insight into a battery's internal state [40,41] …”

Application of Nondestructive Testing Technology in Device‐Scale for Lithium‐Ion Batteries

“…[73] The difference in acoustic impedance between the anode and cathode and the difference in stresses generated during the charging and discharging processes may both contribute to this phenomenon. [63,74] Besides, Sextl et al investigated the relationship between fast and slow waves in ultrasound and battery SoC. [72a] As shown in Figure 10c, the peak height and ToF of the fast wave were constant with the change of SoC, while the peak height of the slow wave was proportional to SoC and ToF was inversely proportional to SoC.…”

“…[ 62 ] Ultrasound imaging is utilized to visualize this process which propagates differently in different media. [ 63 ] In a dry electrode, a solid electrode particle is the only propagation medium, whereas, in a wet electrode, an electrolyte can be another way (Figure 9b). [ 64 ] As a result, the ultrasonic signals obtained in the two situations are significantly different.…”