Tin-based intermetallic compounds proposed as negative electrode materials for Li-ion batteries not only suffer from capacity fade during cycling due to volume variations but also from aging phenomena in lithiated states. By using FeSn2 as a model compound, we propose an analysis of this process by combining electrochemical potential measurements, 119Sn and 57Fe Mössbauer spectroscopies, magnetic measurements, and impedance spectroscopy. We show that the Fe/Li7Sn2 composite obtained at the end of the first discharge is progressively transformed during the aging process occurring within the electrochemical cell in open circuit condition. The Fe nanoparticles are stable while the Li7Sn2 nanoparticles are progressively delithiated with time leading to Sn-rich LixSn nanoalloys without observable back reaction with Fe. The deinserted lithium atoms react with the electrolyte and modify the surface electrode interphase (SEI) by increasing its thickness and/or decreasing its porosity
Aging Processes in Lithiated FeSn2 Based Negative Electrode for Li- Ion Batteries: A New Challenge for Tin Based Intermetallic Materials / Chamas, M; Mahmoud, A; Tang, Jl; Sougrati, Mt; Panero, Stefania; Lippens, Pe. - In: JOURNAL OF PHYSICAL CHEMISTRY. C.. - ISSN 1932-7455. - STAMPA. - 121:(2017), pp. 217-224. [10.1021/acs.jpcc.6b11302]
Aging Processes in Lithiated FeSn2 Based Negative Electrode for Li- Ion Batteries: A New Challenge for Tin Based Intermetallic Materials
PANERO, Stefania;
2017
Abstract
Tin-based intermetallic compounds proposed as negative electrode materials for Li-ion batteries not only suffer from capacity fade during cycling due to volume variations but also from aging phenomena in lithiated states. By using FeSn2 as a model compound, we propose an analysis of this process by combining electrochemical potential measurements, 119Sn and 57Fe Mössbauer spectroscopies, magnetic measurements, and impedance spectroscopy. We show that the Fe/Li7Sn2 composite obtained at the end of the first discharge is progressively transformed during the aging process occurring within the electrochemical cell in open circuit condition. The Fe nanoparticles are stable while the Li7Sn2 nanoparticles are progressively delithiated with time leading to Sn-rich LixSn nanoalloys without observable back reaction with Fe. The deinserted lithium atoms react with the electrolyte and modify the surface electrode interphase (SEI) by increasing its thickness and/or decreasing its porosityI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
