CeO2 quantum-dots engineering 3D carbon architectures toward dendrite-free Na anode and reversible Te cathode for high-performance Na-Te batteries

Abstract

Sodium-tellurium (Na-Te) battery, thanks to high theoretical capacity and abundant sodium source, has been envisaged as one promising battery technology, its practical application yet faces daunting challenges regarding how to mitigate the critical issues of uncontrollable dendrites growth at Na anode and polytellurides shuttling effect at Te cathode. We here report an elaborative design for fabrication of microsphere skeleton nanohybrids with three-dimensional (3D) hierarchical porous carbon loading CeO2 quantum dots (CeO2-QDs/HPC), which feature highly favorable properties of sodiophilic and catalysis for hosting sodium and tellurium, respectively. The systematic investigations coupling with first-principle calculations demonstrate the CeO2-QDs/HPC not only offers favorable structure and abundant electrocatalytic sites for facilitating interconversion between Te and NaxTe as a cathode host, but also can function as dendrite inhibitor anode host for reversible sodium electro-plating/deposition. Such Na-Te battery exhibits admiring electrochemical performance with an impressive specific capacity of 392 mAh g−1, a long cycling stability over 1000 cycles, as well as remarkably high energy density of 192 Wh kg−1 based on the total mass of anode and cathode. Such proof-of-concept bifunctional host design for active electrode materials can render a new insight and direction to the development of high-performance Na-Te batteries. (Figure presented.).