Formation of NiCo2 V2 O8 Yolk-Double Shell Spheres with Enhanced Lithium Storage Properties.

Complex nanostructures with multi-components and intricate architectures hold great potential in developing high-performance electrode materials for lithium-ion batteries (LIBs). Herein, we demonstrate a facile self-templating strategy for the synthesis of metal vanadate nanomaterials with complex chemical composition of NiCo2 V2 O8 and a unique yolk-double shell structure. Starting with the Ni-Co glycerate spheres, NiCo2 V2 O8 yolk-double shell spheres are synthesized through an anion-exchange reaction of Ni-Co glycerate templates with VO3- ions, followed by an annealing treatment. By virtue of compositional and structural advantages, these NiCo2 V2 O8 yolk-double shell spheres manifest outstanding lithium storage properties when evaluated as anodes for LIBs. Impressively, an extra-high reversible capacity of 1228 mAh g-1 can be retained after 500 cycles at a high current density of 1.0 Ag-1 .