Microwave Synthesis of LiFePO 4 from Iron Carbonyl Complex

Enhancement of Li2ZrO3 Modification of the Cycle Life of N/S-Doped LiMn0.5Fe0.5PO4/C Composite Cathodes for Lithium Ion Batteries

LiMn_0.5Fe_0.5PO₄ cathodes have a high energy density but a poor rate and poor cycling performance. To this end, a series of N/S-doped LiMn_0.5Fe_0.5PO₄/C composite cathodes modified with different contents of Li₂ZrO₃ were prepared by a solvothermal synthesis combined with calcination. The microstructure, chemical composition, and electrochemical properties are analyzed. Li₂ZrO₃ adsorbed on the LiMn_0.5Fe_0.5PO₄ primary particles' surface in an amorphous state and on spherical particles (5-10 nm). The cycling life and rate performance of the cathodes are improved by the modification of a moderate amount of Li₂ZrO₃. The LMFP/NS-C/LZO1 shows available capacities of 166.8 and 118.9 mAh·g^-1 at 0.1 and 5 C, respectively. The LMFP/NS-C/LZO1 shows no capacity loss after 100 cycles of charging/discharging (1 C), and still has a high capacity retention of 92.0% after 1000 cycles of charging/discharging (5 C). The excellent cycling performance of the LMFP/NS-C/LZO1 can be attributed to the improvement of the cathode microstructure and the electrochemical kinetics and the inhibition of Mn²⁺ dissolution by the moderate Li₂ZrO₃ modification.

Microwave-Assisted Synthesis: Can Transition Metal Complexes Take Advantage of This “Green” Method?

Microwave-assisted synthesis is considered environmental-friendly and, therefore, in agreement with the principles of green chemistry. This form of energy has been employed extensively and successfully in organic synthesis also in the case of metal-catalyzed synthetic procedures. However, it has been less widely exploited in the synthesis of metal complexes. As microwave irradiation has been proving its utility as both a time-saving procedure and an alternative way to carry on tricky transformations, its use can help inorganic chemists, too. This review focuses on the use of microwave irradiation in the preparation of transition metal complexes and organometallic compounds and also includes new, unpublished results. The syntheses of the compounds are described following the group of the periodic table to which the contained metal belongs. A general overview of the results from over 150 papers points out that microwaves can be a useful synthetic tool for inorganic chemists, reducing dramatically the reaction times with respect to traditional heating. This is often accompanied by a more limited risk of decomposition of reagents or products by an increase in yield, purity, and (sometimes) selectivity. In any case, thermal control is operative, whereas nonthermal or specific microwave effects seem to be absent.

SC. Microwave synthesis of molybdenum doped LiFePO4/C and its electrochemical studies

A Mo-doped LiFePO₄composite was prepared successfully from an iron carbonyl complex by adopting a facile and rapid microwave assisted solid state method.