Elevated electrochemical property of LiMn2O4 originated from nano-sized Mn3O4

By employment of nano-sized pre-prepared Mn 3 O 4 as precursor, LiMn 2 O 4 particles have been successfully prepared by facile solid state method and sol-gel route, respectively. And the reaction mechanism of the used precursors of Mn 3 O 4 is studied. The structure, morphology, and element distribution of the as-synthesized LiMn 2 O 4 samples are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Compared with LiMn 2 O 4 synthesized by facile solid state method (SS-LMO), LiMn 2 O 4 synthesized by modified sol-gel route (SG-LMO) possesses higher crystallinity, smaller average particle size (~175 nm), higher lithium chemical diffusion coefficient (1.17 × 10 −11 cm 2 s −1 ), as well as superior electrochemical performance. For example, the cell based on SG-LMO can deliver a capacity of 85.5 mAh g −1 at a high rate of 5 °C, and manifests 88.3% capacity retention after 100 cycles at 0.5 °C when cycling at 45 °C. The good electrochemical performance of the cell based on SG-LMO is ascribed mainly to its small particle size, high degree of dispersion, and uniform element distribution in bulk material. In addition, the lower polarization potential accelerates Li + ion migration, and the lower atom location confused degree maintains integrity of crystal structure, both of which can effectively improve the rate capability and cyclability of SG-LMO.