Lithiated bimetallic oxide, Li_3Fe(MoO_4)_3, as a high-performance anode material for lithium-ion batteries and its multielectron reaction mechanism

摘要

The lithiated bimetallic oxide, Li3Fe(MoO4)(3), is successfully synthesized by a glycine-assisted sol-gel combustion method at a low temperature in short time. Attributed to the large amount of gas generated in the combustion reaction, the morphology of the sample exhibits a fluffy porous nature like a coral, which is helpful for buffering the volume expansion in the charge/discharge process and improving the structural stability of the electrode material. Combined with the fluffy porous nature and the realization of a multielectron reaction, as-prepared Li3Fe(MoO4)(3) exhibits an excellent electrochemical performance, where a high reversible capacity of 988.2 mAh g(-1) can be obtained at a current density of 100 mA g(-1). Using in situ X-ray diffraction and high-resolution transmission electron microscopy technologies, the complex reaction mechanism of Li3Fe(MoO4)(3) during the lithium insertion/extraction process is discussed in detail for the first time. For the Li3Fe(MoO4)(3 )electrode, the reversible reaction mechanism is a typical conversion reactions between the metal element and the corresponding oxide amorphous phase. In addition, the practical application of Li3Fe(MoO4)(3) as anode material is also studied. When combined with a layered structure LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode in full cells, Li3Fe(MoO4)(3) presents good capacity and cycling stability.