Abstract:
Transition metal sulfides have great potential as anode materials for sodium-ion batteries (SIBs) due to their high theoretical specific capacities. However, the inferior intrinsic conductivity and large volume variation during sodiation–desodiation processes seriously affect its high-rate and long-cycle performance, unbeneficial for the application as fast-charging and long-cycling SIBs anode. Herein, the three-dimensional porous Cu
1.81S/nitrogen-doped carbon frameworks (Cu
1.81S/NC) are synthesized by the simple and facile sol–gel and annealing processes, which can accommodate the volumetric expansion of Cu
1.81S nanoparticles and accelerate the transmission of ions and electrons during Na
+ insertion/extraction processes, exhibiting the excellent rate capability (250.6 mAh·g
−1 at 20.0 A·g
−1) and outstanding cycling stability (70% capacity retention for 6000 cycles at 10.0 A·g
−1) for SIBs. Moreover, the Na-ion full cells coupled with Na
3V
2(PO
4)
3/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g
−1 at 5.0 A·g
−1 and long-cycle performance with the 86.9% capacity retention at 2.0 A·g
−1 after 750 cycles. This work proposes a promising way for the conversion-based metal sulfides for the applications as fast-charging sodium-ion battery anode.