  Thermoelectric (TE) conversion technology, capable of transforming heat into
electricity, is critical for sustainable energy solutions. Many promising TE
materials contain rare or toxic elements, so the development of cost-effective
and eco-friendly high-performance TE materials is highly urgent. Herein, we
explore the thermal transport and TE properties of transition metal vanadate
CuVO3 by using first-principles calculation. On the basis of unified theory of
heat conduction, we uncover the hierarchical thermal transport feature in
CuVO3, where wave-like tunneling makes a significant contribution to the
lattice thermal conductivity (\k{appa}l) and result in the anomalously weak
temperature dependence of \k{appa}l. This is primarily attributable to the
complex phononic band structure caused by the heterogeneity of Cu-O and V-O
bonds. Simultaneously, we report a high power factor of 5.45 mW K-2 m-1
realized in hole-doped CuVO3, which arises from a high electrical conductivity
and a large Seebeck coefficient enabled by the multiple valleys and large
electronic density of states near the valence band edge. Impressively, the low
\k{appa}l and the high power factor make p-typed CuVO3 have ZT of up to 1.39,
with the excellent average ZT above 1.0 from 300 to 600 K, which is superior to
most reported Cu-based TE materials. Our findings suggest that CuVO3 compound
is promising candidate for energy conversion applications in innovative TE
devices.
