Silver Honeycomb Layered Tellurate Exhibiting Ag Subvalency and Metallophilic Bilayers

Silver (Ag+) conducting electrolytes are already being pursued for utilisation in solid-state batteries (e.g. [1] ). Herein, we fortuitously synthesise a novel class of honeycomb layered tellurates, characterised by a global composition of Ag2 M 2TeO6 (where M = Co, Ni etc represents transition metals). These compounds feature argentophilic Ag-atom bilayers (Figure 1), as revealed through aberration-corrected transmission electron microscopy. [2,3,4] Due to metallophilicity and Ag subvalency, impalpable challenges reproducing the Ag bilayered structure exist within standard computational techniques. [5] Thus, the origin of the bilayers is theoretically understood via the emergence of non-commutative gauge interactions with three distinct valency states of Ag associated with well-known subvalent states, alongside the usual electromagnetic interaction. [2,3,4,6] Breaking these gauge symmetries generates a mass term, corresponding to the bifurcation of the Ag honeycomb lattice into argentophilic bilayers. [3,4] Moreover, since this novel class displays oxygen anion electrochemistry and relatively fast ionic conductivities, this work not only promises to inspire next-generation Ag-based honeycomb layered oxide cathodes but also provide a platform for further inquiry into the novel role of non-Euclidean and non-commutative geometries and gauge interactions respectively play within the broader class of honeycomb layered materials typically poised for secondary battery applications. [3,6,7,8,9] References: [1] K. Kirshenbaum et al., Handbook of Solid State Batteries, 779-818 (2016) [2]T. Masese, G. M. Kanyolo, Y. Miyazaki, T. Saito et al., Adv . S ci., 10, 2204672 (2024) [3]G. M. Kanyolo, T. Masese, Y. Miyazaki, T. Saito et al., Prog . Mater. S ci., 141, 101205 (2024) [4]G. M. Kanyolo, T. Masese et al., Mater . Today Chem., 33, 101657 (2024) [5] K. Tada, T. Masese, and G. M. Kanyolo, Comput. Mater. Sci. 207 111322 (2022) [6]G. M. Kanyolo and T. Masese, Mater . Today Phys., 39, 101271 (2024) [7]G. M. Kanyolo, T. Masese et al., Chem. Soc. Rev ., 50, 3990 (2021) [8] G. M. Kanyolo and T. Masese, Sci. Rep. 12 (1) 6465 (2022) [9] G. M. Kanyolo and T. Masese, arXiv:2202.10323 [cond-mat.mtrl-sci] Figure 1. HAADF-STEM image taken along [100] axis illustrating bilayer arrangement of silver atoms in honeycomb layered oxides with a global composition of Ag2Ni2TeO6. [2,3] Figure 1