In Situ Real-Time Mechanical and Morphological Characterization of Electrodes for Electrochemical Energy Storage and Conversion by Electrochemical Quartz Crystal Microbalance with Dissipation Monitoring

Abstract

Quartz crystal microbalance with dissipation monitoring (QCM-D) generates surface-acoustic waves in quartz crystal plates that can effectively probe the structure of films, particulate composite electrodes of complex geometry rigidly attached to quartz crystal surface on one side and contacting a gas or liquid phase on the other side. The output QCM-D characteristics consist of the resonance frequency (MHz frequency range) and resonance bandwidth measured with extra-ordinary precision of a few tenths of Hz. Depending on the electrodes stiffness/softness, QCM-D operates either as a gravimetric or complex mechanical probe of their intrinsic structure. For at least 20 years, QCM-D has been successfully used in biochemical and environmental science and technology for its ability to probe the structure of soft solvated interfaces. Practical battery and supercapacitor electrodes appear frequently as porous solids with their stiffness changing due to interactions with electrolyte solutions or as a result of ion intercalation/adsorption and long-term electrode cycling. Unfortunately, most QCM measurements with electrochemical systems are carried out based on a single (fundamental) frequency and, as such, provided that the resonance bandwidth remains constant, are suitable for only gravimetric sensing. The multiharmonic measurements have been carried out mainly on conducting/redox polymer films rather than on typical composite battery/supercapacitor electrodes. Here, we summarize the most recent publications devoted to the development of electrochemical QCM-D (EQCM-D)-based methodology for systematic characterization of mechanical properties of operating battery/supercapacitor electrodes. By varying the electrodes' composition and structure (thin/thick layers, small/large particles, binders with different mechanical properties, etc.), nature of the electrolyte solutions and charging/cycling conditions, the method is shown to be operated in different application modes. A variety of useful electrode-material properties are assessed noninvasively, in situ, and in real time frames of ion intercalation into the electrodes of interest. A detailed algorithm for the mechanical characterization of battery electrodes kept in the gas phase and immersed into the electrolyte solutions has been developed for fast recognition of stiff and viscoelastic materials in terms of EQCM-D signatures treated by the hydrodynamic and viscoelastic models. Working examples of the use of in situ hydrodynamic spectroscopy to characterize stiff rough/porous solids of complex geometry and viscoelastic characterization of soft electrodes are presented. The most demonstrative example relates to the formation of solid electrolyte interphase on LiTiO electrodes in the presence of different electrolyte solutions and additives: only a few cycles (an experiment during ∼30 min) were required for screening the electrolyte systems for their ability to form high-quality surface films in experimental EQCM-D cells as compared to 100 cycles (200 h cycling) in conventi...

Quartz Crystal Microbalance With Dissipation Monitoring: A Versatile Tool to Monitor Phase Transitions in Biomimetic Membranes

“…Excellent reviews on the working principle and data analysis can be found in Dixon (2008), Reviakine et al (2011), Johannsmann (2015. In the last decade, QCM-D has been successfully used in biotechnology and environmental science as a tool for investigating the structure and mechanics of soft and solvated interfaces (Dixon, 2008;Kanazawa and Cho, 2009;Campos et al, 2015), as well as hydrodynamic phenomena in non-uniform nanostructured surfaces (Shpigel et al, 2018). It has been particularly relevant in the field of lipid biophysics, as a useful technique to understand the kinetics of formation of supported lipid bilayers (Keller and Kasemo, 1998;Richter et al, 2003;Cho et al, 2010;Lind and Cárdenas, 2016), and their interactions with relevant biomolecules (Mechler et al, 2007;Michanek et al, 2010;Nielsen and Otzen, 2013).…”

Microgravimetric and Spectroscopic Analysis of Solid−Electrolyte Interphase Formation in Presence of Additives

“…Recently, a real breakthrough in the microgravimetric analysis of the battery electrode interfaces has been achieved by applying QCM in combination with dissipation monitoring. Using this set‐up in a multiharmonic mode the mechanical properties of Sn/electrolyte interface and the viscoelastic behavior of Li 4 Ti 5 O 12 and LiFePO 4 composite electrode coatings are revealed . Nevertheless, the in‐situ analysis of SEI formation and its mechanical properties is limited only to Sn/electrolyte and Li 4 Ti 5 O 12 /electrolyte interfaces.…”

“…Using this set-up in a multiharmonic mode the mechanical properties of Sn/electrolyte interface and the viscoelastic behavior of Li 4 Ti 5 O 12 and LiFePO 4 composite electrode coatings are revealed. [16][17][18][19] Nevertheless, the in-situ analysis of SEI formation and its mechanical properties is limited only to Sn/electrolyte and Li 4 Ti 5 O 12 /electrolyte interfaces. Hence, there is a large application window of this methodology for characterizing the mechanical and morphological properties of the SEI layer deposited under the influence of various functional additives.…”

Electrochemically Reduced Graphene Oxide‐Sheltered ZnO Nanostructures Showing Enhanced Electrochemical Performance Revealed by an In Situ Electrogravimetric Study

“…Compared with the ZnO nanostructures grown on the graphene, where only upper graphene surface is available to electrolyte, a thin layer of graphene covered ZnO nanostructures is postulated to provide higher number of electroactive sites for charge storage due to the accessibility of both surfaces (upper and lower) to electrolyte, allowing for more effective charge and mass exchange. The study of such architectures with coupled methods such as coupling electrochemistry with gravimetric analysis, i.e., quartz crystal microbalance (QCM) can significantly contribute to their further development.Electrochemical quartz crystal microbalance (EQCM) has developed into a powerful in situ technique to measure ionic fluxes in different electrochemical systems, [18][19][20][21][22][23][24] in which not only the current response (ΔI) but also the in situ capturing of global gravimetric change (Δm) at the electrode/electrolyte interface is The present work is on the synthesis and characterization of vertically aligned ZnO nanostructures sheltered by electrochemically reduced graphene oxide (ERGO), i.e., ZnO@ERGO, which are directly generated on quartz resonators of microbalance sensors. [3] However, fundamental importance of the ionic flux into the electrode, which plays an essential role in understanding the charge-storage mechanism of a specific electrochemical system is generally underestimated.…”

“…Electrochemical quartz crystal microbalance (EQCM) has developed into a powerful in situ technique to measure ionic fluxes in different electrochemical systems, [18][19][20][21][22][23][24] in which not only the current response (ΔI) but also the in situ capturing of global gravimetric change (Δm) at the electrode/electrolyte interface is The present work is on the synthesis and characterization of vertically aligned ZnO nanostructures sheltered by electrochemically reduced graphene oxide (ERGO), i.e., ZnO@ERGO, which are directly generated on quartz resonators of microbalance sensors. The vertical orientation of the ZnO nanorods is achieved by a two-step synthesis method involving an electrochemically grown seed layer and a subsequent hydrothermal growth.…”