“…[ 18 ] This can be effectively achieved by the introduction of defects, such as 0D point defects, [ 19–22 ] 1D dislocations, [ 23,24 ] and 2D nanostructures, [ 25–27 ] for a strong phonon scattering. Moreover, utilizing the intrinsic features, including complex crystal structures, [ 5,28–30 ] liquid‐like ions, [ 31,32 ] weak chemical bonding, [ 28,33,34 ] and low cutoff frequency of acoustic phonons, [ 35 ] also results in a low κ L .…”