Li-storage and cyclability of urea combustion derived ZnFe2O4 as anode for Li-ion batteries

The cubic ZnFe2O4 with the spinel structure is prepared by the urea combustion method. Powder X-ray diffraction and HR-TEM studies confirm the single-phase nature with particle size in the range, 100–300 nm. A stable and reversible capacity, 615(±10) mAh g−1 (5.5 moles of Li per mole of ZnFe2O4) when cycled in the range, 0.005–3.0 V vs. Li at a current of 60 mA g−1(0.1C) has been achieved between 15 and 50 cycles. The underlying reaction mechanism contributing to the observed capacity is the combination of ‘de-alloying–alloying’ and ‘conversion’ reactions of ‘LiZn–Fe–Li2O composite’. Ex situ HR-TEM and SAED data on the charged-electrode confirmed the proposed reaction mechanism.