Abstract
-
To develop a long cycle life and good rate capability electrode, 3D hierarchical
porous α-Fe2O3 nanosheets are fabricated on copper foil and directly used
as binder-free anode for lithium-ion batteries. This electrode exhibits a high
reversible capacity and excellent rate capability. A reversible capacity up to
877.7 mAh g −1 is maintained at 2 C (2.01 A g −1 ) after 1000 cycles, and even
when the current is increased to 20 C (20.1 A g −1 ), a capacity of 433 mA h g −1
is retained. The unique porous 3D hierarchical nanostructure improves electronic–
ionic transport, mitigates the internal mechanical stress induced by
the volume variations of the electrode upon cycling, and forms a 3D conductive
network during cycling. No addition of any electrochemically inactive
conductive agents or polymer binders is required. Therefore, binder-free electrodes
further avoid the uneven distribution of conductive carbon on the current
collector due to physical mixing and the addition of an insulator (binder),
which has benefi ts leading to outstanding electrochemical performance.