About this Research Topic
Battery material research has been one of the major areas of study in the last ~30 years due to the huge impact of battery technology in our daily lives. Both the discovery of new materials and their electrochemical optimization requires an in-depth and fundamental understanding of the composition and structure at different length scales. Local, long-range structure, polymorphism, microstructure, composite formulation and nanoscale engineering all contribute to a materials innate ability to deliver the best performance as an electrode in a battery. Importantly, the evolution of all these components during battery function determine essentially all the pertinent battery characteristics such as lifetime and energy storage density. For these reasons, it is critical to determine materials structure at various length scales, in order to be able to predict or understand their properties and propose changes to improve their electrochemical behavior. In this sense, conventional characterization techniques of the material itself are very useful in the first stages of research but, in many cases, the use of in-situ or in operando characterization techniques provides a unique way of understanding materials performance or evolution during battery operation. The challenge becomes greater in terms of experimental design because these techniques involve devising and fabricating specific electrochemical cells that fulfill the requirements of the technique but deliver electrochemical performance akin to a real-life device.
Many in-situ characterization techniques have been implemented for Li-ion and Na-ion batteries and recently K-ion, Li-S and to some extent Li-O2 batteries. These range from:
• Neutron and synchrotron X-ray diffraction for long-rang ordered structural information,
• Solid-state NMR or X-ray absorption spectroscopy for local or shorter range structural information
• Raman spectroscopy for tracking charge/discharge products
• X-ray photoelectron spectroscopy for surface structure.
Over time, these techniques are becoming more and more widely used and in the future some of them will likely become a staple technique to elucidate battery materials structure-function relationships. All these techniques make up a great bundle of resources to go inside battery materials during operation, such as to probe the crystal structure evolution of electrodes while an electrochemical process is occurring inside a battery, even tracking lithium or sodium ion migration paths, to follow how the redox couple and its environment evolve, or even to be able to observe how electrode-electrolyte interface develops.
There is a distinct opportunity to obtain unparalleled insight into the structure and electrochemistry or property relationships inside batteries from which research and development can be stimulated and performance potentially exponentially enhanced. In this Research Topic we wish to create a means to illustrate the state of the art for in-situ and in-operando techniques and their results. We welcome submissions in the form of perspectives, mini-reviews, reviews and exemplary original research covering the spectrum of techniques.
Keywords: Battery, Electrode, In-situ, In-operando, Spectroscopy
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.