Study of Solid Electrolyte Interface Formation and Lithium Intercalation in Li-Ion Batteries by Acoustic Emission

Abstract

This paper has the aim to demonstrate that Acoustic Emission (AE) is an appropriate technique to become a diagnostic tool for state of charge, state of health and state of security of lithium-ion cells. These issues are actually key parameters for both performance and durability improvement. The presented results deal with the monitoring of the SEI formation and the first lithium ion intercalation on the surface and inside the graphite electrode. AE events coming from different sources have thus been identified. A large number of acoustic emission events occur during the film formation corresponding to gas evolution and cracking processes happening at the electrode surface (lithium intercalation). The acoustic emission signals were analyzed and correlated with electrochemical phenomena taking place during the cell operation.

The Sound of Batteries: An Operando Acoustic Emission Study of the LiNiO2 Cathode in Li–Ion Cells

“…Accordingly, the imaging data in combination with the EIS results support our conclusion that the first increase in acoustic activity is because of cSEI formation (see also Figure S8 of the Supporting Information for high-and low-magnification SEM images recorded after charging to different voltages in the initial cycle). [39][40][41] This also corroborates indirectly our assumption that the AE detected beyond the monoclinic phase and up to the upper cutoff voltage is due to crack formation (Figure 4c and d), and this is further confirmed by direct comparison with the following cycles. In the second charge cycle, the already formed cSEI was clearly visible by SEM until~3.8 V. Only for higher voltages (� 4.0 V), notable fracture of the primary and Batteries & Supercaps secondary particles was apparent (see Figure S9 of the Supporting Information).…”

“…[17,18] Based on both test measurements and literature data, a possible contribution of the lithium anode to the acoustic activity can be neglected (see Figure S2 of the Supporting Information). [39,49] Using electrochemical impedance spectroscopy (EIS), Zhan et al suggested the successive formation/growth of cSEI layers with different properties: a resistive layer followed by its conversion into a more conductive cSEI. [50,51] Hence, the further increase in acoustic activity from 3.9 to 4.3 V (HV region) may be explained by growth/conversion of the initial cSEI.…”

“…For instance, Kircheva et al used AE to probe the solid-electrolyte interphase (SEI) formation and lithium intercalation into the bulk of graphite electrodes. [39] Moreover, Choe et al analyzed damage mechanisms in lithium cobalt oxide (LiCoO 2 , LCO) and graphite electrodes by classifying AE signals into distinct types, [40] and Villevieille et al investigated conversion-type reactions in NiSb 2 electrodes. [41] Other LIB materials, such as silicon and metal hydrides, have also been studied; yet, Ni-rich layered oxide cathode materials have not been examined to date.…”

Electrolytes and Interphases in Li-Ion Batteries and Beyond

“…Kircheva et al revealed that the acoustic hits or the absolute energy released recorded in the first cycle far outnumbered those in the subsequent cycles ( Figure 58b). 644 They attributed the source of these acoustic events to the formation of SEI accompanied by the generation of gaseous products as well as fracture of graphite crystallites during Li + -intercalation. Note that the largest accumulated energy occurred during the voltage range 1.5−0.75 V, which was considered to be the potential range where carbonate molecules start to decompose reductively.…”

Operando flow regime diagnosis using acoustic emission in a polymer electrolyte membrane water electrolyser

“…Rhodes et al [21] monitored particle fracture in Sibased anodes of Li-ion batteries and showed that the fracture of Si particles can be modelled using a thermal analogy model [22]. This technique has also been applied to Li/NiSb2 batteries [23], solid electrolyte interface (SEI) formation and Li intercalation in Li-ion batteries [24], solid oxide fuel cell seal cracking [25,26], Nafion dehydration [27], and flooding [28] and localised operation [29] in polymer electrolyte membrane fuel cells.…”