Smart construction of three-dimensional hierarchical tubular transition metal oxide core/shell heterostructures with high-capacity and long-cycle-life lithium storage

In order to realize new high performance electrodes for lithium-ion batteries (LIBs), the careful design of nanoarchitectures and effective hybridization of active materials are research areas of great interest. Here, we present a simple and highly controllable two-step fabrication technique, followed by a heat treatment process, for the large-scale in situ growth of 3D hierarchical tubular CuO/other metal oxides core/shell heterostructure arrays that are directly grown on Cu foam. As a proof-of-concept demonstration of the application of such 3D hierarchical tubular heterostructure arrays, the prepared tubular CuO/CoO core/shell arrays are investigated as binder- and conductive agent-free anodes for LIBs, exhibiting an impressive capacity of 1364mAhg^-1 at a current density of 100mAg^-1 after 50 cycles and maintaining 1140mAhg^-1 after 1000 cycles at 1.0Ag^-1. This excellent electrochemical performance can be attributed to the unique hollow porous architecture consisting of 3D hierarchical tubular core/shell architectures, and the effective hybridization of two electrochemically cohesive active materials. Our work shows that this material has great potential for high-energy and high-power energy storage applications.