Hierarchical hollow-structured anode for high-rate sodium-ion battery

Thanks to its larger surface and free volume, hollow nanostructure and nanomaterials are one kind of highly desirable electrodes for efficiently enhancing sodium-ion battery performance, especially at high rate. Herein, we demonstrate a design of hierarchical semi-open hollow structure, assembling with molybdenum selenide (MoSe2) nanosheets embedded on the nitrogen doped carbon matrix. The unique hollow structure can not only enable sufficient electrode/electrolyte interaction and fast electron transportation, but also suppress volume expansion during the insertion/extraction of sodium ion. As a direct outcome, the MoSe2/carbon anode exhibits excellent cycling and rate performance with a specific capacity of 431 mAh g(-1) at 200 mA g(-1), maintaining 87.7% capacity after 120 cycles. Notably, a discharge capacity of 199.1 mAh g(-1) can be achieved even at an ultra-high current density of 20 A g(-1), indicating quick Na+ storage ability. The results may open a new way to realize high-rate anode for ion battery applications.