Nanoparticles-constructed spinel ZnFe2O4 anode material with superior lithium storage performance boosted by pseudocapacitance

Abstract The practical application of ZnFe2O4 in lithium ion batteries (LIBs) is severely hampered by its fast capacity fading and poor rate performance. To overcome these issues, herein, ZnFe2O4 powders consist of aggregated nanoparticles (50∼100 nm) with porosity were prepared by a facile co-precipitation method and subsequent thermal decomposition. When used as anode material for LIBs, the ZnFe2O4 sample delivers capacities of 920, 820, 650, 485, and 421 mA h g−1 at current densities of 0.5, 1, 3, 7, and 10 A g−1, respectively. Moreover, the sample can maintain a capacity of 814 mA h g−1 even after 300 cycles at the current density of 1 A g−1, implying an excellent rate capability and cycling stability. Cyclic voltammetry analysis reveals that both diffusion-controlled lithium storage and surface pseudocapacitive lithium storage contribute to the total stored charge of ZnFe2O4, which boosts the high rate capability and superior cycling stability of the ZnFe2O4.