Transition metal sulfides (TMSs) with high theoretical specific capacity and superior electrochemical performance are promising anode material candidates for sodium-ion batteries (SIBs). However, the structural pulverization because of the severe volume change in the discharge/charge process leads to a severe capacity decay, limited rate performance, and poor cycling stability, which inhibits their practical application. Herein, we report a novel strategy for the synthesis of TMS hollow nanoparticles@carbon fibers (TMS-HNP@CFs- T) by using seaweed-derived alginate as the template and precursor. When evaluated as anode materials for SIBs, the hybrids display excellent sodium storage performance. For instance, CoS-HNP@CFs-900 exhibits high reversible specific capacity, significant cycling stability (392.2 mA h g-1 at 1000 mA g-1 over 100 cycles), and rate performance (334.2 mA h g-1 can be achieved at 5000 mA g-1). The hollow TMP NPs and conductive carbon fibers could synergistically reduce the expansion of volume and shorten the ion transport path to boost the sodium storage performance.
Keywords: alginate fiber; anode materials; hollow nanoparticles; sodium-ion battery; transition metal sulfides.