Thermomechanical Polymer Binder Reactivity with Positive Active Materials for Li Metal Polymer and Li-Ion Batteries: An XPS and XPS Imaging Study

Abstract

The lithium and lithium-ion battery electrode chemical stability in the pristine state has rarely been considered as a function of the binder choice and the electrode processing. In this work, X-ray photoelectron spectroscopy (XPS) and XPS imaging analyses associated with complementary Mössbauer spectroscopy are used in order to study the chemical stability of two pristine positive electrodes: (i) an extruded LiFePO4-based electrode formulated with different polymer matrices [polyethylene oxide and a polyvinylidene difluoride (PVdF)] and processed at different temperatures (90 and 130 °C, respectively) and (ii) a Li­[Ni0.5Mn0.3Co0.2]­O2 (NMC)-based electrode processed by tape-casting, followed by a mild or heavy calendering treatment. These analyses have allowed the identification of reactivity mechanisms at the interface of the active material and the polymer in the case of PVdF-based electrodes.

Stabilizing lithium metal anode by octaphenyl polyoxyethylene-lithium complexation

“…In C 1s XPS spectrum (Fig. 4a), compared with untreated electrolyte, the electrolyte with OP-10 or PEGDME contains more different peaks, the visible peak at 286.7, 284.7, and 284 eV are found from the surface of Li electrode, which can be attributed to ethylene oxide group of OP-10/PEGDME, benzene group, and Li-C-O bond, respectively [42][43][44][45][46] . While in O 1s, the peak at 533.8 eV is assigned to the characteristic peak of Li-C-O, which is both observed in the cell using OP-10 or PEGDME as additives, but it could not observe in the cell using blank electrolyte 44 .…”

Performance and ageing behavior of water-processed LiNi0.5Mn0.3Co0.2O2/Graphite lithium-ion cells

“…Carbon black particles contribute mainly to the C-C/C-H peak in the C 1s spectrum. CH2 and CF2 groups in PVDF binder are revealed in the lines at 286.2 and 290 eV respectively for the electrode F0 40,41 .…”

“…The latter functional group also contributes to the peak near 687.2 eV in the F 1s spectrum 40,41 . In the water-based electrodes F1' and F2-c, the binders are composed of 1wt% Na-CMC and 2wt% latex with acrylic functions.…”

Selective adsorption-involved formation of NMC532/PANI microparticles with high ageing resistance and improved electrochemical performance

“…After 100 cycles at 1C, the broad peaks in NMC532-RT F 1 s can be fitted into three components centered at 684.6 ± 0.3, 685.6 ± 0.5, and 686.8 ± 0.4 eV, corresponding separately to MÀF, Li-F and covalent F (Fig. 7a) [52,56,64]. The covalent F results from LiPF 6 /Li x PO y F z (P-F) and PVDF (C-F), which can be degraded during charge/discharge cycles [64].…”

“…7a) [52,56,64]. The covalent F results from LiPF 6 /Li x PO y F z (P-F) and PVDF (C-F), which can be degraded during charge/discharge cycles [64]. As the thinning number increases, the concentration of covalent F increases whereas the Li-F concentration decreases in the F 1 s spectra of NMC532-RT ( Fig.…”