Operando acoustic emission monitoring of degradation processes in lithium-ion batteries with a high-entropy oxide anode

Abstract

In recent years, high-entropy oxides are receiving increasing attention for electrochemical energy-storage applications. Among them, the rocksalt (Co0.2Cu0.2Mg0.2Ni0.2Zn0.2)O (HEO) has been shown to be a promising high-capacity anode material. Because high-entropy oxides constitute a new class of electrode materials, systematic understanding of their behavior during ion insertion and extraction is yet to be established. Here, we probe the conversion-type HEO material in lithium half-cells by acoustic emission (AE) monitoring. Especially the clustering of AE signals allows for correlations of acoustic events with various processes. The initial cycle was found to be the most acoustically active because of solid-electrolyte interphase formation and chemo-mechanical degradation. In the subsequent cycles, AE was mainly detected during delithiation, a finding we attribute to the progressive crack formation and propagation. Overall, the data confirm that the AE technology as a non-destructive operando technique holds promise for gaining insight into the degradation processes occurring in battery cells during cycling.

How beam damage can skew synchrotron operando studies of batteries

“…Operando experiments in batteries have offered valuable insights into the mechanisms at play inside the devices and thus have been performed us-ing a variety of probes, e.g. neutrons, photons (from visible light to X-rays), electrons, acoustic or nuclear magnetic resonance [1,2,3,4,5,6,7,8]. In particular, synchrotron radiation techniques such as spectroscopy, imaging or diffraction offer a good penetration depth, element selectivity, and a large sensitivity that enable fast acquisitions, taking advantage of the intense photon flux available.…”

High‐entropy oxide: A future anode contender for lithium‐ion battery

“…The amount of evolved gas was appreciably reduced after the second cycle, while the onset potential of C 2 H 4 evolution shifted to a lower position, indicating the formation of a rather stable SEI. For the first time, Schweidler et al 45 monitored the capacity attenuation mechanism of HEO anode by acoustic emission technology. The acoustic responses in the first lithiation cycle (0.3-0.01 V vs. Li + /Li) and each subsequent delithiation cycle (>1 V) can be respectively assigned to chemical mechanical decay (including particle fracture and pulverization) and progressive crack formation/propagation (Figure 4A), which offers the possibility to limit mechanical decay by adjusting the potential window.…”

“…Reproduced with permission. 45 Copyright 2021, Springer Nature. (B) Cycling performance of S-HEO synthesized by alloy oxidation.…”

The effect of configurational entropy on acoustic emission of P2-type layered oxide cathodes for sodium-ion batteries

“…LiCoO 2 [43], LiMnO 2 [44], LiNiO 2 [39] and HE Li x (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2 )OF x [45]] and anode active materials [e.g. graphite [46], silicon [47][48][49], NiSb 2 [50] and HE (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2 )O [51]]. For these materials, analysis of AE signals, with a single acoustic event usually referred to as a hit, allows gaining insights into solid electrolyte interphase (SEI) formation on the one hand and crack formation and propagation both on the particle and electrode level on the other hand.…”

“…For these materials, analysis of AE signals, with a single acoustic event usually referred to as a hit, allows gaining insights into solid electrolyte interphase (SEI) formation on the one hand and crack formation and propagation both on the particle and electrode level on the other hand. These processes can be distinguished by signal classification due to acoustic wave characteristics, such as peak frequency, rise time, duration or amplitude [39,[43][44][45][46][47]51].…”