<b>Although
the fascinatingly rich crystal chemistry of honeycomb layered oxides has been
accredited as the propelling force behind their remarkable electrochemistry,
the atomistic mechanisms surrounding their operations remain unexplored. Thus,
herein, we present an extensive molecular dynamics study performed
systematically using a refined set of inter-atomic potential parameters of <i>A</i><sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub>
(where <i>A</i> = Li, Na, and K). We
demonstrate the effectiveness of the Vashishta-Rahman form of the interatomic
potential in reproducing various structural and transport properties of this
promising class of materials and predict an exponential increase in cationic
diffusion with larger interlayer distances. The simulations further demonstrate
the correlation between broadened inter-layer (inter-slab) distances associated
with the larger ionic radii of K and Na compared to Li and the enhanced
cationic conduction exhibited in K<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> and
Na<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> relative to Li<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub>.
Whence, our findings connect lower
potential energy barriers, favourable cationic paths and wider bottleneck size
along the cationic diffusion channel within frameworks (comprised of larger
mobile cations) to the improved cationic diffusion experimentally observed in
honeycomb layered oxides. Furthermore, we explicitly study the role of
inter-layer distance and cationic size in cationic diffusion. Our theoretical
studies reveal the dominance of inter-layer distance over cationic size, a
crucial insight into the further performance enhancement of honeycomb layered
oxides.</b><br>
Phosphoric acid and thermal treatments reveal the peculiar role of surface oxygen anions in lithium and manganese-rich layered oxides
