Non-invasive in situ dynamic monitoring of elastic properties of composite battery electrodes by EQCM-D.
Reversible Li-ion intercalation into composite Li-ion battery (LIB) electrodes is often accompanied by significant dimensional electrode changes (deformation) resulting in significant deterioration of the cycling performance. Viscoelastic properties of polymeric binders affected by intercalation-induced deformation of composite LIB electrodes have never been probed in situ on operating electrochemical cells. Here, we introduce a newly developed noninvasive method, namely electrochemical quartz-crystal microbalance with dissipation monitoring (EQCM-D), for in situ monitoring of elastic properties of polymeric binders during charging of LIB electrodes. As such, we find EQCM-D as a uniquely suitable tool to track the binder's structural rigidity/softness in composite Li insertion electrodes in real-time by the characteristic increase/decrease of the dissipation factor during the charging-discharging process. The binders partially swollen in aprotic solutions demonstrate intermediate viscoelastic charge-rate-dependent behavior, revealing rigid/soft behavior at high/low charging rates, respectively. The method can be adjusted for continuous monitoring of elastic properties of the polymeric binders over the entire LIB electrodes cycling life.
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel).
Netanel
N
Shpigel
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel). levimi@biu.ac.il.
Mikhael D
MD
Levi
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel).
Sergey
S
Sigalov
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel).
Olga
O
Girshevitz
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel). aurbach@biu.ac.il.
Doron
D
Aurbach
School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Ramat Aviv, 69978 (Israel).
Leonid
L
Daikhin
INM-Leibniz Institute for New Materials, 66123 Saarbrücken (Germany).|Department of Materials Science and Engineering, Saarland University, 66123 Saarbrücken (Germany).
Nicolas
N
Jäckel
INM-Leibniz Institute for New Materials, 66123 Saarbrücken (Germany).|Department of Materials Science and Engineering, Saarland University, 66123 Saarbrücken (Germany).
Volker
V
Presser
Li-ion batteries; deformations; polymeric binders; quartz-crystal microbalance; viscoelasticity