Cerium vanadate/carbon nanotube hybrid composite nanostructures as a high-performance anode material for lithium-ion batteries

Abstract

Li + insertion/de-insertion process into/out for the pristine CeVO 4 and CeVO 4 /CNT HCNS electrodes. • Pristine CeVO 4 and CeVO 4 /CNT HCNS were successfully prepared via a silicone oil-bath method. • The Li insertion/de-insertion electrochemical reaction with the CeVO 4 was analyzed. • The discharge performance of CeVO 4 /CNT HCNS electrode was improved compared to the pristine CeVO 4 . • The electrode delivered a reversible capacity of 586.82 mA h g −1 after 1200 cycles at 500 mA g −1 . The pristine CeVO 4 and CeVO 4 /CNT hybrid composite nanostructured samples were facilely synthesized using a simple silicone oil-bath method. From the X-ray diffraction results, the formation of tetragonal CeVO 4 with an additional minor phase of V 2 O 5 was identified. When investigated as an anode material for lithium (Li)-ion batteries, the CeVO 4 /CNT hybrid composite nanostructure (HCNS) electrode demonstrated improved Li storage performance over the pristine CeVO 4 . The Li insertion/de-insertion electrochemical reaction with the CeVO 4 was analyzed on the basis of cyclic voltammetry study. The cyclic voltammetry analysis revealed that the three-step reduction of V 5+ to V 3+ , V 3+ to V 2+ , and V 2+ to V + processes is involved and among them, only V 5+ to V 3+ is reversible during the Li-ion insertion into CeVO 4 . The CeVO 4 /CNT HCNS electrode exhibited a discharge capacity as high as 443 mA h g −1 (capacity retention of 96.3%) over 200 cycles at 100 mA g −1 , whereas the pristine CeVO 4 is limited to 138 mA h g −1 (capacity retention of 48%). Even at a high current density of 500 mA g −1 , the CeVO 4 /CNT HCNS electrode delivered an excellent reversible capacity of 586.82 mA h g −1 after 1200 cycles.