The battery chemistry must be diversified to achieve a sustainable energy landscape by effectively utilizing renewable energy sources. Alkali metal-ion, all-solid-state, metal-air batteries, and multivalent batteries offer unique cost, safety, raw material abundance, energy, and power density solutions. However, realizing these “Beyond Li-ion batteries” must uncover their working principles and performance & property relationship. In this aspect, mitigating chemo-mechanical instabilities in the structure and surface of the electrodes plays a crucial role in their performance. Unfortunately, the coupling between electrochemical and mechanical interactions is often poorly understood due to a lack of operando characterization. This review article explains the working principles of curvature measurement and digital image correlation for measuring stress and strain generations in battery materials. We provided specific examples of how these operando mechanical measurements shed light on instabilities in alkali-metal ion electrodes, solid electrolytes, Li-O2 batteries, and aqueous Zn-ion batteries. Operando mechanical measurements offer an effective way to map changes in the physical fingerprint of the battery materials, therefore providing crucial information to elucidate instabilities in battery materials. 
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                            Nanographene Cathode Materials for Nonaqueous Zn-Ion Batteries
                        
                    
    
            Robust multivalent ion interaction in electrodes is a grand challenge of next-generation battery research. In this manuscript, we design molecularly-precise nanographene cathodes that are coupled with metallic Zn anodes to create a new class of Zn-ion batteries. Our results indicate that while electrodes with graphite or flat nanographenes do not support Zn-ion intercalation, the larger intermolecular spacing in a twisted peropyrene enables peropyrene electrodes to facilitate reversible Zn-ion intercalation in an acetonitrile electrolyte. While most previous Zn-ion batteries utilize aqueous electrolytes, the finding that nonaqueous Zn electrolytes can support intercalation in nanographenes is important for expanding the design space of nonaqueous multivalent batteries, which often possess higher voltages than their aqueous counterparts. Furthermore, because these nanographenes can be synthesized using a bottom-up approach via alkyne benzannulation, this work paves the way for future battery electrodes that contain other molecularly-precise nanographenes with tailored electrochemical properties. 
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                            - Award ID(s):
- 2046105
- PAR ID:
- 10400599
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 169
- Issue:
- 11
- ISSN:
- 0013-4651
- Page Range / eLocation ID:
- 110517
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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