Tin–Transition Metal–Carbon Systems for Lithium-Ion Battery Negative Electrodes

Abstract

Magnetron cosputter deposited ternary libraries of (, V and Co) ( and ) have been studied structurally and electrochemically using combinatorial and high-throughput methods. Each of the sputtered binary systems shows an amorphous composition range where the specific capacity for lithium decreases with M content. Adding carbon to the amorphous binaries, to make ternaries, causes the precipitation of crystalline Sn in the cases when or V, but not when . We believe this is because stable carbides of Ti and V exist but stable Co carbides do not. The sputtered system was found to have a large amorphous range and the initial amorphous atomic arrangement in certain compositions are stable over at least 27 charge-discharge cycles of . Crystalline Sn was found to precipitate in composition ranges having competitive specific capacity in the and libraries causing rearrangement of the atoms during cycling leading to poor capacity retention.