Polyoxometalate Cluster-Incorporated High Entropy Oxide Sub-1 nm Nanowires.

High entropy oxides (HEOs) with fascinating physical and chemical properties have exhibited unprecedented application potential in many fields. However, it remains a huge challenge to realize the precise control of the dimension and morphology at the sub-1 nm scale. Herein, with the aid of polyoxometalate (POM) clusters, we first develop a versatile strategy to realize the controllable incorporation of multiple immiscible metal oxides into sub-1 nm nanowires (SNWs) under 140 °C to obtain a wide range of HEO-POM SNWs with highly ordered structures, where the species of metal oxides and POMs could be regulated flexibly. Meanwhile, these obtained HEO materials are first to be used as anodes in Na-ion batteries. Benefiting from the effect of entropy modulation, these HEO-POM SNWs show better electrochemical properties in Na-ion batteries with the increase of metal oxide species stepwise. A long cycle life with a capacity retention of ∼92% even after 5000 cycles at 10C further confirms the good stability under fast discharging/charging. This method opens a new insight for designing and preparing HEOs at the sub-1 nm scale under facile conditions.