Periodic Reporting for period 1 - Electroscopy (Electrochemistry of All-solid-state-battery Processes using Operando Electron Microscopy)
Berichtszeitraum: 2020-11-01 bis 2022-10-31
The overarching objective of the project Electroscopy is to advance all-solid-state battery (ASSB) technology. ASSBs offer a safer alternative to the traditional Li-ion battery with liquid electrolytes and thus are the focus of research throughout the world.
However, electrode-electrolyte interface problems pose a change to commercialization. In this project, I have utilized in situ transmission electron microscopy (TEM) and scanning electron microscopy (SEM), to obtain key information about battery process and materials. For this both solid-solid and solid-liquid electrode-electrolyte interfaces are studied in situ during battery operation and the material synthesis process is visualized to fast-forward ASSB technology.
However, electrode-electrolyte interface problems pose a change to commercialization. In this project, I have utilized in situ transmission electron microscopy (TEM) and scanning electron microscopy (SEM), to obtain key information about battery process and materials. For this both solid-solid and solid-liquid electrode-electrolyte interfaces are studied in situ during battery operation and the material synthesis process is visualized to fast-forward ASSB technology.
• I have used in situ TEM experiments to gain insight into the suitable TiO2 coating thickness that can be applied to the electrode particles. The result showed thickness-dependent coating rupture during battery cycling where thicker coatings crumble more readily than thinner coatings.
• Extending the above, I have prepared a protocol for screening the electrode/electrolyte coatings based on in situ TEM experiments. The current protocol presents an alternative procedure in which the potential coatings are applied on Si nanoparticles and are subjected to (de)lithiation during operando TEM experiments. The high volume changes of Si nanoparticles during (de)lithiation allow monitoring of the coating behaviour at relatively low magnification and offer a quick screening of potential coatings.
• In situ SEM is used to monitor the sintering behaviour of solid electrolytes. The in situ observation would allow optimizing phase purity, structure, and grain sizes of solid electrolytes.
These results have been disseminated as peer-reviewed open-access articles. I have written a review article where I have stressed the importance of correlation microscopy e.g. XCT when interpreting TEM data and linking the connection from nano to macro.
• Extending the above, I have prepared a protocol for screening the electrode/electrolyte coatings based on in situ TEM experiments. The current protocol presents an alternative procedure in which the potential coatings are applied on Si nanoparticles and are subjected to (de)lithiation during operando TEM experiments. The high volume changes of Si nanoparticles during (de)lithiation allow monitoring of the coating behaviour at relatively low magnification and offer a quick screening of potential coatings.
• In situ SEM is used to monitor the sintering behaviour of solid electrolytes. The in situ observation would allow optimizing phase purity, structure, and grain sizes of solid electrolytes.
These results have been disseminated as peer-reviewed open-access articles. I have written a review article where I have stressed the importance of correlation microscopy e.g. XCT when interpreting TEM data and linking the connection from nano to macro.
Aqueous electrolyte-based batteries go beyond the state-of-art and offer a futuristic solution to the energy challenge. Understanding the in-depth behavior of aqueous electrolyte-based battery processes requires creating a well-controlled chemical environment inside TEM and the lack of such liquid cells makes systematic studies with liquid electrolyte challenging. Thanks to the MSCA fellowship, I have collaborated with DENSSolutions and developed the know-how to create a well-controlled chemical environment using MEMS chips. These MEMS chips allow control of liquid thickness as well as electrolyte flow control. This work has been disseminated in form of a journal publication. I have further utilized these chips to study Zn deposition at various flow conditions and utilized advanced microscopy techniques to unveil important details about Zn deposition and stripping mechanism shedding light on how to control dendritic deposition. This paper will be submitted soon to a peer-review journal.
Silicon is one of the most attractive anode materials but the micron or bigger-sized particles break into smaller pieces during battery cycling leading to capacity loss. Silicon in the lab-scale is only used in form of nanoparticles to counter the volume expansion during lithiation and the industrial-scale production of these nanoparticles is one of the main bottlenecks. Now if one can find a way to balance the size and the morphology, by creating a porous structure, we can still use bigger-scale particles. I have looked into the workings of these porous electrodes using in situ TEM and X-ray tomography techniques. This paper too will be submitted soon to a peer-review journal.
Silicon is one of the most attractive anode materials but the micron or bigger-sized particles break into smaller pieces during battery cycling leading to capacity loss. Silicon in the lab-scale is only used in form of nanoparticles to counter the volume expansion during lithiation and the industrial-scale production of these nanoparticles is one of the main bottlenecks. Now if one can find a way to balance the size and the morphology, by creating a porous structure, we can still use bigger-scale particles. I have looked into the workings of these porous electrodes using in situ TEM and X-ray tomography techniques. This paper too will be submitted soon to a peer-review journal.