Highly uniform nitrogen-doped carbon decorated MoO2 nanopopcorns as anode for high-performance lithium/sodium-ion storage

Molybdenum dioxides (MoO 2 ) featuring low cost and high theoretical capacity endow them competitive anode materials for lithium-ion batteries (LIBs)/sodium-ion batteries (SIBs). However, the low electrical conductivity and severe volume expansion occurring during the ion insertion/extraction process hamper their practical application. Herein, a novel dual-annealing design has been developed for the synthesis of highly uniform MoO 2 nanopopcorns decorated with nitrogen-doped carbon shell (MoO 2 /NC). Owing to the unique structural characteristics and vital amorphous NC component, the MoO 2 /NC nanopopcorn hybrid composite exhibits stabilized charge storage capacity of 1073 mAh g −1 after 200 cycles for LIBs, while 301 mAh g −1 after 500 cycles for SIBs at 0.5 A g −1 . Furthermore, when the current density increases to 5 A g −1 , the specific capacity could still maintain 630 mAh g −1 and 174 mAh g −1 for LIBs and SIBs, respectively, which disclose the outstanding rate capability of MoO 2 /NC nanopopcorn anode.