Spectroscopy — Operando Raman and ex situ characterization of an iron-based conductive MOF as a negative electrode in Li-ion batteries

7 measurement groups · 12 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

Fresh and cycled Fe-HHTP composite electrodes stopped at 0.1 V or 3 V · Electrode

Fresh non-cycled electrode and fully activated electrodes stopped at 0.1 V and 3 V; Renishaw inVia, 532 nm, 10% power, 60 s for cycled electrodes.

Atmosphere: cycled electrodes washed with DMC and dried under vacuum before ex situ Raman
Geometry: composite electrodes in Raman cell
Context: fresh and cycled composite electrodes containing Fe-HHTP
Measurement source: 7 · 2.3 Study of the electrochemical mechanism · Figure 5a

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source

synthesised Fe-HHTP powder · Powder

Bruker FTIR Vertex 70; 4000-600 cm-1; 40 scans averaged.

Geometry: powder
Context: pristine Fe-HHTP powder with HHTP ligand comparison
Measurement source: 10 · 4.2 Powder and electrodes ex situ characterization techniques · Figure 1c

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Powder FTIR band positions	approximately 3200 cm-1 (O-H), 1615 cm-1 (C=O), 1440 cm-1 (C=C), 1225 cm-1 (C-O), 1000 cm-1 (C-OH); HHTP C=C at approximately 1530 cm-1 disappears after coordination	—	—	Text Approximate	3 · 2.1 MOF powder characterization · Figure 1c

Fresh and cycled Fe-HHTP composite electrodes stopped at 0.1 V or 3 V · Electrode

Cycled electrodes stopped at 0.1 V (lithiated) and 3 V (delithiated); spectra shown over 2170-600 cm-1 and 3740-3525 cm-1.

Atmosphere: cycled electrodes washed with DEC and dried under vacuum before measurement
Geometry: composite electrodes
Context: cycled composite electrodes containing Fe-HHTP
Measurement source: 6 · 2.3 Study of the electrochemical mechanism · Figure 4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Fresh electrode FTIR bands	1625 cm-1 (C=O), 1255 cm-1 (C-O), 1074 cm-1 (C-C)	—	—	Text Exact Reported	6 · 2.3 Study of the electrochemical mechanism · Figure 4a
Cycled electrode FTIR lithium/oxygen interaction bands	new 1315 cm-1 band with 1255 cm-1; weak sharp high-frequency bands at 3676 and 3566 cm-1 assigned to LiOH/LiOH.H2O after air exposure	—	—	Text Exact Reported	6 · 2.3 Study of the electrochemical mechanism · Figure 4

Rectangular Fe-HHTP composite electrode in adapted operando Raman cell · Electrode

Renishaw inVia, 50x objective, 532 nm, 1% power, two accumulations, 90 s acquisition; Bio-Logic SP-150 applied galvanostatic current; CaF2 window.

Atmosphere: sealed adapted electrochemical Raman cell assembled in Ar glovebox
Geometry: rectangular electrode in Li electrochemical Raman cell
Context: composite Fe-HHTP electrode in operando Li cell
Measurement source: 10 · 4.3 Electrochemical measurements and operando Raman · Figure 5b; Figure S11

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Operando Raman aromatic C-C red-shift during lithiation	clear red-shift of the 1385 cm-1 band during lithiation, ascribed to decreased aromatic C-C bond strength	—	—	Text Rounded Reported	6 · 2.3 Study of the electrochemical mechanism · Figure 5b
Operando Raman open-circuit shifted bands	C-C stretching and HHTP breathing bands at 1588 cm-1 and 1373 cm-1 in open-circuit conditions	—	—	Text Exact Reported	6 · 2.3 Study of the electrochemical mechanism · Figure 5b
Fe-O Raman peaks in open-circuit conditions	Fe-O peaks at 567 cm-1 and 642 cm-1 show a red-shift during lithiation	—	—	Text Exact Reported	7 · 2.3 Study of the electrochemical mechanism · Figure 5b

synthesised Fe-HHTP powder · Powder

Dried powder in airtight Raman cell with borosilicate window; Renishaw inVia, 50x objective, 532 nm, 10% power, 1 accumulation, 20 s acquisition.

Atmosphere: airtight cell to avoid atmospheric water readsorption
Geometry: powder in Raman cell
Context: pristine Fe-HHTP powder
Measurement source: 10 · 4.2 Powder and electrodes ex situ characterization techniques · Figure 1d; Table S1

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Powder Raman band assignments	215, 280, 395, 492, 589, 642 cm-1 Fe-HHTP/Fe-O modes; 1050 cm-1 HHTP delta CH; 1345 cm-1 HHTP breathing; 1462 cm-1 catecholate; 1575 cm-1 HHTP nu CC; 2780 cm-1 overtone	—	—	SI Table Exact Reported	13 · Table S1 · Table S1

Fresh and cycled Fe-HHTP composite electrodes stopped at 0.1 V or 3 V · Electrode

Fresh electrode and lithiated/delithiated electrodes stopped at 0.1 V and 3 V after 1, 20 and 200 galvanostatic cycles.

Atmosphere: cycled electrodes washed with DEC and dried under vacuum before measurement
Geometry: composite electrodes
Context: cycled composite electrodes containing Fe-HHTP
Measurement source: 5 · 2.3 Study of the electrochemical mechanism · Figure 3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
C 1s evolution with cycling	C-Li interaction peak near 290.2 eV increases with cycles and is larger in lithiated electrodes; C=C/C-C and C=O/C-O ratios reduce in lithiated samples	—	—	Text Rounded Reported	5 · 2.3 Study of the electrochemical mechanism · Figure 3a
Fe redox/conversion during lithiation	Fe3+ reduces to Fe2+ during lithiation; Fe0 appears in lithiated samples at cycles 20 and 200 and weakly after 200-cycle delithiation	—	—	Text Qualitative	5 · 2.3 Study of the electrochemical mechanism · Figure 3b

synthesised Fe-HHTP powder · Powder

AXIS SupraTM with monochromated Al Kalpha = 1486.6 eV; C-C peak calibrated at 284.8 eV; CasaXPS analysis.

Geometry: powder
Context: pristine Fe-HHTP powder
Measurement source: 10 · 4.2 Powder and electrodes ex situ characterization techniques · Figure 1b; Figure S3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
C 1s component binding energies	283.9 eV (C=C), 284.8 eV (C-C), 285.9 eV (C-O), 287.8 eV (C=O), 290.4 eV (pi-pi stacked layers)	—	—	Text Rounded Reported	2 · 2.1 MOF powder characterization · Figure S3b
Fe oxidation state	mixed +2/+3	—	—	Text Qualitative	2 · 2.1 MOF powder characterization · Figure 1b
O 1s component binding energies	530.99 eV (Fe-O), 532.02 eV (C-O), 532.74 eV (C=O), 534.85 eV (O-H)	—	—	Text Rounded Reported	2 · 2.1 MOF powder characterization · Figure S3c