Study on the performance of MnO${}_2$-MoO${}_3$ composite as lithium-ion battery anode using spent Zn-Mn batteries as manganese source

The recycling of Zn-Mn batteries was linked with the synthesis of MnO${}_2$-MoO${}_3$ composite in this paper. An intermediate product of MnSO${}_4$ was recycled from spent Zn-Mn batteries by hydrometallurgy recycling technology, and it was selected as manganese source to synthesize MnO${}_2$-MoO${}_3$ composite via a facile one-step hydrothermal method. The composition, morphology, and valence state of the final product MnO${}_2$-MoO${}_3$ are characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. As anode for lithium-ion batteries, the obtained composite of MnO${}_2$-MoO${}_3$ on copper foil presents outstanding electrochemical performance. The composite attains an initial specific capacity of 2333.1 mAh g${}^{-1}$ and stays 908.8 mAh g${}^{-1}$ after 50 cycles at a current rate of 100 mA g${}^{-1}$ in the voltage range of 0.01–3.0 V, much higher than that of pure MnO${}_2$. Even at a high current rate of 500 mA g${}^{-1}$, the capacity still remains at 371.1 mAh g${}^{-1}$ after 50 cycles. Moreover, the lithiation and delithiation processes of MnO${}_2$-MoO${}_3$ anode material were investigated in detail by X-ray diffraction characterization.