Department of Physics, Panjab University, Chandigarh, India

TPSC seminar

Date and time: 14 February 2018 (Wednesday), 4:00 pm
Venue: Seminar Hall

Title: Clusters as building blocks of energy materials

Speaker: Prof. P. Jena, Distinguished Professor, Department Physics, Virginia Commonwealth University, Richmond, Virginia, USA

Abstract: Atomic clusters possess uncommon properties, which can be tailored by varying their size, structure, and composition, one atom at a time [1]. A quarter century ago it was suggested [2] that clusters, mimicking the chemistry of atoms, can be used to create a new three dimensional periodic table and that such clusters can be assembled to build novel materials. In this talk I will describe the progress that has been made in this regard. In particular, I will focus on two classes of clusters called superhalogens and superalkalis. The former have electron affinities that far exceed those of halogens and the later have ionization potentials that are lower than those of alkalis. These superions can be used to synthesize a new class of super-salts with applications in energy harvesting and storage. I will discuss how simple electron counting rules can be used to design these superions, which can then form the building blocks of halogen-free electrolytes in Li-ion batteries [3] as well as all solid-state batteries based on anti-perovskites [4]. If time permits, I will also discuss the design of water-resistant hybrid organic-inorganic solar cells [5] with super- and pseudo-halogens as building blocks. These results based on density functional theory will be validated by comparing with available experiment.
[1] Jena, P. and Castleman, Jr., A. W.: Clusters: A bridge across the disciplines of Physics and Chemistry, Proc. Nat. Acad. of Sciences, 103, 10560 (2006).
[2] Khanna, S.N. and Jena, P.: On Assembling Crystals from Clusters, Phys. Rev. Lett. 69, 1664 (1992).
[3] Giri, S., Behera, S., and Jena, P.: Superhalogens as Building Blocks of Halogen-freeElectrolytes in Li-ion Batteries, Angew. Chem. Int. Ed. 53, 13916 (2014).
[4] Fang, H. and Jena, P.: Li-rich antiperovskite superionic conductors based on cluster ions, Proc. Nat. Acad. Sci. 14, 1047 (2017).
[5] Fang, H. and Jena, P.: Atomic-level Design of Water-resistant Hybrid Perovskites for Solar Cells, J. Phys. Chem. Letts8, 3726 (2017).