Upadhyayula V Varadaraju

The exchange of lithium for univalent copper in CuNbO3 has been investigated. A new form of LiNbO3 with a lamellar structure has been synthesized from the topotactic reaction between CuNbO3 and a molten salt corresponding to the eutectic "LiCl/LiNO3". This compound crystallizes in the P21/a space group with a = 9.433 Å, b = 8.226 Å, c = 6.213 Å, and β = 90.2°. This new phase intercalates one lithium on the first discharge and shows reversibility of 0.7 lithium through a first-order transformation leading to a capacity of 120 mAh/g at a potential of 1.65 V vs Li+/Li. © 2011 American Chemical Society.

The monoclinic form of FeOHSO4 was prepared by dehydration of FeSO4·7H2O. We show that reversible insertion of up to ∼1Li/f.u. is possible in this compound at an average voltage of 3.2 V. The insertion/deinsertion is a biphasic process. The high voltage plateau, a reversible capacity of 110 mAh/g after 20 cycles and good cycling behavior make this compound an attractive positive electrode material for rechargeable Li-ion batteries, suggesting also that transition metal sulphates need to be explored. © 2009 Elsevier B.V. All rights reserved.

An original synthesis method for the synthesis of hydrated iron trifluorides is presented for the first time. This method, based on solvothermal process starting from iron salt and HF in alcool, is economic, simple and environmentally benign. The electrochemical performances of the composite phase FeF3·0.5H2O/graphene is showing enhanced capacity of 200 mAh/g at C/20.

An original synthesis method for the synthesis of hydrated iron trifluoride is presented. This method, based on solvothermal process starting from iron salt and HF in alcool, is economic and simple. The electrochemical performances of the composite phase FeF3·0.33H2O/Graphitic oxide is showing enhanced capacity of 250 mAh/g at 0.05 °C.