Electrochemical insertion of lithium into YBa 2Cu 3O 7- y

Abstract

Lithium insertion into the superconductor YBa 2Cu 3O 7- y has been studied with the cell Li| 1 M LiClO 4 in PC|Li x YBa 2 Cu 3O 7- y . The open circuit voltage of the cell decreases gradually from 3.4 V to 2.2 V as the lithium content x increases from 0 to 0.3. Then a voltage plateau is reached that continues up to x=1.0. The chemical diffusion coefficient of lithium has been determined by the galvanostatic intermittent titration technique. A value of 1.65 to 2.13 × 10 −7 cm 2/s for x<0.1 is obtained. The reversibility of the lithium insertion was shown by voltammetry and repeated cycling of YBa 2Cu 3O 7- y . A battery has been made with a capacity of 24.4 mAh, corresponding to a volume capacity of 256.7 Ah/1.