Unfolding tin-cobalt interactions in oxide-based composite electrodes for li-lon batteries by Mossbauer spectroscopy

With a view to the development of new composite electrodes for lithium-ion batteries with electroactive tin and cobalt Co-doped tin dioxide samples are studied. The role played by oxygen and cobalt atoms in the electrochemical behavior of tin-based electrodes for Li-ion batteries is examined by the powerful and selective Sn-119 Mossbauer spectroscopy. For the discharged electrodes, the oxygen atoms in the lithio matrix tend to destabilize the Sn(0) atoms. In contrast, the presence of cobalt atoms helps to form a matrix that stabilizes the reduced tin atoms. Cobalt-tin interactions in electrochemical reduced CoxSn1-xO2 electrodes ore deduced from the electrochemical and Mossbauer results.