Sn-based intermetallic materials

Ni ₃Sn ₄ and CoSn ₂ which are two Sn-based intermetallic compounds with different crystal structures have been tested as future negative electrodes for lithium-ion batteries. Various two-step reactions occur during the first discharge of these two electrodes. The first discharge shows good specific capacities: 515 mAh g ⁻¹ for the Ni ₃Sn ₄ electrode and 606 mAh g ⁻¹ for the CoSn ₂ electrode. These reactions lead to the formation of Li ₇Sn ₂, a Li-rich Li _xSn alloy characterized by ¹¹⁹ Sn Mössbauer spectroscopy.