Electrochemical lithium insertion in the hexagonal cesium vanadium bronze Cs0.35V2O5

The vanadium bronze Cs0.35V2O5 has been synthesized by a sol-gel process, I t exhibits a hexagonal symmetry with lattice parameters a = 13.341(1) Angst rom, c = 3.610(1) Angstrom. These are very close to those given for Cs0.3V2 O5 obtained by high temperature solid state reaction. Preliminary results o n the electrochemical lithium insertion in the tunnel structure of the bron ze Cs0.35V2O5 show two main insertion steps in the potential range 3.5-1.8 V with a maximum Li uptake of 1.65. The irreversible trapping of some Li io ns limits the cycling capacity to 145 A h kg(-1) in the Voltage range 4.2-1 .8 V at a C/10 rate. (C) 1999 Elsevier Science S.A. All rights reserved.