Sintering Temperature Induced Evolution of Microstructures and Enhanced Electrochemical Performances: Sol-Gel Derived LiFe(MoO4)2 Microcrystals as a Promising Anode Material for Lithium-Ion Batteries

Abstract

A facile sol-gel process was used for synthesis of LiFe(MoO4)2 microcrystals. The effects of sintering temperature on the microstructures and electrochemical performances of the as-synthesized samples were systematically investigated through XRD, SEM and electrochemical performance characterization. When sintered at 650°C, the obtained LiFe(MoO4)2 microcrystals show regular shape and uniform size distribution with mean size of 1–2 μm. At the lower temperature (600°C), the obtained LiFe(MoO4)2 microcrystals possess relative inferior crystallinity, irregular morphology and vague grain boundary. At the higher temperatures (680 and 700°C), the obtained LiFe(MoO4)2 microcrystals are larger and thicker particles. The electrochemical results demonstrate that the optimized LiFe(MoO4)2 microcrystals (650°C) can deliver a high discharge specific capacity of 925 mAh g−1 even at a current rate of 1 C (1,050 mA g−1) after 500 cycles. Our work can provide a good guidance for the controllable synthesis of other transition metal NASICON-type electrode materials.

Compositing redox-rich Co–Co@Ni–Fe PBA nanocubes into cauliflower-like conducting polypyrrole as an electrode material in supercapacitors

“…51 The peak at 712.1 eV was ascribed to Fe 2p 3/2 , representing Fe 3+ . 52 All the Fe peaks also shifted towards higher BEs with respect to Co–Co@Ni–Fe core–shell PBA. Hence, the iron in the Ni–Fe PBA was present in mixed oxidation states of Fe 2+ and Fe 3+ as both Ni 2+ –CN–Fe 3+ and Ni 2+ –CN–Fe 2+ .…”