Electrochemical behaviors of SnO and Sn anodes for lithium rechargeable batteries

Electrochemical behaviors of Sn and SnO anodes are studied. Charging/discharging curves show irreversible capacities at the first cycle in both Sn and SnO electrodes. The irreversible capacity loss in Sn electrode is due to the incomplete Li removal from Sn after the first cycle. Although the largest capacity loss in SnO electrode is a result from the lithia formation during the first discharge, additional capacity loss arises from the residual Li in metallic Sn owing to the aggregation of Sn upon repeated cycling. Contrary to the previous studies, Li22Sn5 phase is not observed in the discharge product in Sn and SnO electrodes. The LiSn alloy electrode shows almost 100% cycling efficiency at the first cycle due to the pre-existing Li.

Research highlights► We carefully examined the discharge products in SnO and Sn electrodes during the first cycle. ► We observed the incomplete removal of Li from Sn after the first charge which causes the capacity loss in Sn electrode. ► The additional capacity loss due to the residual Li in metallic Sn was observed in SnO electrode. ► The LiSn alloy electrode showed almost 100% cycling efficiency at the first cycle due to the pre-existing Li.