Electrochemical lithium intercalation in lead-tin-aluminium solder

Electrochemical lithiation in a lead-tin-aluminium (ca. 1:2:1 atomic ratio) solder has been examined with a view to possible use as an anode material in Li-ion batteries. Electrochemical tests were carried out in a three-electrode laboratory metal cell against a lithium metal anode. The electrolyte used was 0.8 M LiPF6 + 0.2 M LiClO4 in ethylene carbonate/dimethyl carbonate/diethyl carbonate in the volume ratio 1:1:1. Charge and discharge cycles were carried out at a constant current density of 0.885 mA cm(-2) over the voltage range 10-900 mV. X-ray powder diffraction patterns were collected at various stages in the cycle and phases identified and refined by Rietveld analysis. Results are compared with those from cells containing pure lead and pure tin electrodes. All systems investigated showed a first discharge curve without steps. Subsequent cycling of cells resulted in behaviour more typical of lithium alloys. Loss of capacity in cells after extended cycling is attributed to macrostructural changes. (C) 2001 Elsevier Science B.V. All rights reserved.