  Endowed with a multitude of exquisite properties such as rich
electrochemistry, superb topology and eccentric electromagnetic phenomena,
honeycomb layered oxides have risen to the top echelons of science with
applications in diverse fields ranging from condensed matter physics,
solid-state chemistry, materials science, solid-state ionics to
electrochemistry. However, these oxides are vastly underutilised as their
underlying atomistic mechanisms remain unexplored. Therefore, in this study,
atomic-resolution imaging on pristine $\rm K_2Ni_2TeO_6$ along multiple zone
axes was conducted using spherical aberration-corrected scanning transmission
electron microscopy (Cs-corrected STEM) to reveal hitherto unreported nanoscale
topological defects and curvature which can be associated with various phase
transitions. Furthermore, we discover the coexistence of a stacking variant
with P3-type sequence alongside the well-reported P2-type stacking sequence in
such honeycomb layered oxides. Our findings have the potential to inspire
further experimental and theoretical studies into the role of stacking and
topology in the functionality of honeycomb layered oxides, for instance, as
high-performance electrode materials for rechargeable batteries.
