Electrochemical energy storage of NiO/NiFe2O4 nanosheets derived from Ni-Fe layered double hydroxides

A simple method was proposed for synthesis of NiO/NiFe2O4 nanosheets as anode of lithium-ion batteries (LIBs) derived from layered double hydroxides (LDHs). The as-prepared NiO/NiFe2O4 composite exhibited two-dimensional (2D) nanostructures with size of about 500 nm, which can release the mechanical strain and provide available space between adjacent particles for accommodating the large volume expansion during the charge/discharge process. Moreover, 2D nanostructures possessed shortened transport path for Li+ and electrons as well as large exposed surface to supply more Li+ insertion/extraction channels. All of these advantages endowed NiO/NiFe2O4 with good electrochemical performance as lithium-ion battery (LIB) anode. The NiO/NiFe2O4 nanosheets delivered capacity of 772 mAh g−1 at 500 mA g−1 after 60 cycles. This work provided one research route to synthesize transition metal oxides (TMOs) or their composites for LIBs, capacitors, catalysis, and other fields.