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

The vanadium bronze Cs0.35V2O5 has been synthesized by a sol–gel process. It exhibits a hexagonal symmetry with lattice parameters a=13.341(1) Å, c=3.610(1) Å. These are very close to those given for Cs0.3V2O5 obtained by high temperature solid state reaction. Preliminary results on the electrochemical lithium insertion in the tunnel structure of the bronze 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 ions limits the cycling capacity to 145 A h kg−1 in the voltage range 4.2–1.8 V at a C/10 rate.