(Battery Division Student Research Award Address Sponsored by Mercedes-Benz Research & Development) Elucidating the Surface-to-bulk Redox Chemistry and Design Principles of Stable Layered Cathode Materials

Abstract

Alkali-ion batteries have revolutionized modern life through enabling the widespread application of portable electronic devices. The call for adopting renewable energy in many applications will also see an increase in the demand of alkali-ion batteries, specially to account for the intermittent nature of the renewable energy sources. However, the advancement of batteries for such technologies will require innovation on the forefront of materials development as well as fundamental understanding on the physical and chemical processes from atomic to device length scales. In this presentation, we focus on cathode materials development and discovery as well as fundamental understanding through multiscale advanced synchrotron spectroscopy and microscopy. Multiscale electrochemical properties of cathode materials are unraveled through complementary characterizations and design principles are developed for stable cathode materials for Na-ion and Li-ion batteries. We present tuning nano/mesoscale elemental distribution of transition metal on each individual cathode particle as a pathway toward stable cathode materials.1 Surface-to-bulk redox chemistry of cathode particles is elucidated,2 and structural and chemical complexities of Na layered cathodes are explored as a means of designing stable cathode materials.3 We show that local transition metal‒oxygen symmetry induced structural and chemical processes majorly dictate the stability of oxygen redox in layered cathodes.4,5 The critical role of crystal defects on the stability of layered cathodes is unraveled. Finally, design principles of cathode materials for application in extreme environment such as outer space and nuclear reactors is presented.6 Reference M. M. Rahman et al., Energy Environ. Sci., 11, 2496–2508 (2018).M. M. Rahman et al., J. Phys. Chem. C, 123, 11428–11435 (2019).M. M. Rahman et al., ACS Mater. Lett., 1, 573–581 (2019).M. M. Rahman et al., ChemRxiv (2021) https://chemrxiv.org/engage/chemrxiv/article-details/60c75903ee301c953ec7b821.M. M. Rahman and F. Lin, Matter, 4, 490–527 (2021).M. M. Rahman et al., Nat. Commun., 11, 4548 (2020).