Graphene
coating is commonly used to improve the performance of electrode materials,
while its steric hindrance effect hampers fast ion transport with compromised rate capability. Herein, a unique
single-walled carbon nanotubes (SWNTs) coating layer, as an alternative to graphene, has been developed to improve the
battery behavior of iron-based anodes. Benefiting
from the structure merits of mesoporous SWNTs layer for fast electron/ion
transport and hollow Fe
3O
4 for volume accommodation,
as-prepared Fe
3O
4@SWNTs exhibited excellent lithium
storage performance. It delivers a high capacity, excellent rate capability, and long
lifespan with capacities of 582 mA·h·g
-1 at 5 A·g
-1 and 408 mA·h·g
-1 at 8 A·g
-1 remained after 1000 cycles. Such performance is better
than graphene-coated Fe
3O
4 and other SWNT-Fe
3O
4 architectures. Besides, SWNTs coating is also used to improve the sodium and
potassium storage performance of FeSe
2. The kinetics analysis and
ex-situ experiment further reveal the effect of SWNTs coating for fast
electron/ion transfer kinetics and good structure stability, thus leading to
the superior performance of SWNTs-coated composites.