Porous Ni3S4/C aerogels derived from carrageenan-Ni hydrogels for high-performance sodium-ion batteries anode

Abstract Nickel sulfide (Ni 3 S 4 ) has been recognized as one of the most advanced anode materials for sodium-ion batteries (SIBs) on account of its cost effectiveness, commendable redox reversibility and high theoretical capability. However, like other metal sulfide (MS) anodes, the Ni 3 S 4 suffers from poor cycle life and inferior rate capability owing to large volume changes during the repeated Na + de/insertion process and unsatisfied electronic conductivity. Herein, we fabricated porous Ni 3 S 4 /carbon aerogels (Ni 3 S 4 /CAs) using carrageenan-Ni hydrogels as the precursor via the pyrolysis route. The sulfate groups located uniformity and confinement for Ni 2+ ions in carrageenan double-helix structures converted into uniform Ni 3 S 4 nanoparticles (NPs) embedded in porous carbon through the decomposition. Remarkably, the as-prepared Ni 3 S 4 /CAs-1 sample as the anode material for SIBs exhibits a high reversible capacity of 297 mAh g −1 at a current density of 1 A g −1 after 100 cycles. This work develops a facile way to synthesize Ni 3 S 4 /CAs as a promising anode material for SIBs from marine biomass resources.