On the Structure and Electrochemical Reactions with Lithium of Tin(II) Phosphate Chloride

Abstract

A crystalline solid of stoichiometry and orthorhombic structure was characterized and used as electrode material vs. a lithium metal anode. The structure of the solid resembles that of SnO; tin atoms protrude from layers of tetrahedra, while chlorine atoms are located between Sn layers. Two‐electrode electrochemical cells of the type (PC, propylene carbonate: EC, ethylene carbonate) were mounted and discharged to a maximum capacity close to 6.4 faradays per Sn atom. This corresponds to the complete reduction of Sn(II) to Sn(0) followed by the formation of noncrystalline Li‐Sn alloys up to a limiting composition of . The second step of the discharge shows an interesting reversibility. After a decrease in capacity during the first ten cycles, ascribable to the increase in the size of tin domains, the charge and discharge capacities remain close to 300 Ah/kg (Sn) up to ca. 40 cycles. © 2000 The Electrochemical Society. All rights reserved.