Reaction mechanisms of tridymite iron phosphate with lithium ions in the low-voltage range

Kim, Tae-Gon; Lee, Joon-Gon; Son, Dongyeon; Jin, Seonghyun; Kim, Min; Park, Byungwoo

doi:10.1016/j.electacta.2007.08.037

Cited by 11 publications

(4 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the radial distribution function, (inset in Fig. 8a ) the increase of the Fe-(O, OH) distance (+0.1 Å) is also here consistent with a reduction to Fe(II) species 34 .The spectra resemble a mixed valence Fe(III)/Fe(II) phase 31 , note, however, that the sample now clearly contains a small Fe 0 component from the previous reduction step (non-phase-corrected Fe-Fe distance 4.5 Å in inset in Fig. 8a ).…”

Section: Resultssupporting

confidence: 77%

Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon

et al. 2018

View full text Add to dashboard Cite

The carbon–carbon coupling via electrochemical reduction of carbon dioxide represents the biggest challenge for using this route as platform for chemicals synthesis. Here we show that nanostructured iron (III) oxyhydroxide on nitrogen-doped carbon enables high Faraday efficiency (97.4%) and selectivity to acetic acid (61%) at very-low potential (−0.5 V vs silver/silver chloride). Using a combination of electron microscopy, operando X-ray spectroscopy techniques and density functional theory simulations, we correlate the activity to acetic acid at this potential to the formation of nitrogen-coordinated iron (II) sites as single atoms or polyatomic species at the interface between iron oxyhydroxide and the nitrogen-doped carbon. The evolution of hydrogen is correlated to the formation of metallic iron and observed as dominant reaction path over iron oxyhydroxide on oxygen-doped carbon in the overall range of negative potential investigated, whereas over iron oxyhydroxide on nitrogen-doped carbon it becomes important only at more negative potentials.

show abstract

Section: Resultssupporting

confidence: 77%

Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The major peak centered at 0.63 V has been attributed to the irreversible process by which the reduction of Fe 2+ and Co 2+ to their metallic forms occurs. This phenomenon was reported for FePO 4 29 , LiFePO 4 30 and M 0.5 TiOPO 4 (M = Ni, Co and Fe). [25][26][27][28] The third minor peak at 0.36 V can be attributed to the decomposition of the electrolyte, which results in the formation of the solid electrolyte interface (SEI) film.…”

Section: Electrochemical Propertiessupporting

confidence: 73%

Alluaudite Na₂Co₂Fe(PO₄)₃as an electroactive material for sodium ion batteries

et al. 2015

View full text Add to dashboard Cite

The electroactive orthophosphate Na2Co2Fe(PO4)3 was synthesized using a solid state reaction. Its crystal structure was solved using the combination of powder X-ray- and neutron-diffraction data. This material crystallizes according to the alluaudite structure (S.G. C2/c). The structure consists of edge sharing [MO6] octahedra (M = Fe, Co) resulting in chains parallel to [-101]. These chains are linked together via the [PO4] tetrahedra to form two distinct tunnels in which sodium cations are located. The electrochemical properties of Na2Co2Fe(PO4)3 were evaluated by galvanostatic charge-discharge cycling. During the first discharge to 0.03 V, Na2Co2Fe(PO4)3 delivers a specific capacity of 604 mA h g(-1). This capacity is equivalent to the reaction of more than seven sodium ions per formula unit. Hence, this is a strong indication of a conversion-type reaction with the formation of metallic Fe and Co. The subsequent charge and discharge involved the reaction of fewer Na ions as expected for a conversion reaction. When discharged to 0.9 V, the material intercalated only one Na(+)-ion leading to the formation of a new phase Na3Co2Fe(PO4)3. This phase could then be cycled reversibly with an average voltage of 3.6 V vs. Na(+)/Na and a capacity of 110 mA h g(-1). This result is in good agreement with the theoretical capacity expected from the extraction/insertion of two sodium atoms in Na3Co2Fe(PO4)3.

show abstract

“…In fact, previous X-ray diffraction (XRD) studies have shown that these materials lose crystallinity and become amorphous during lithiation [15,17,19,20,25,31], with the detrimental loss of capacity after the first cycle. Like in the case of tridymite iron phosphate [32], the discharge reaction was expected to be similar to the conversion reaction of transition metal oxides [33][34][35], where the lithiation process leads to the decomposition of the oxide and the subsequent formation of metallic nanoparticles dispersed in a lithium oxide matrix.…”

Section: Introductionmentioning

confidence: 99%

Toward understanding the lithiation/delithiation process in Fe0.5TiOPO4/C electrode material for lithium-ion batteries

Lasri

Mahmoud

Saadoune

et al. 2016

Solar Energy Materials and Solar Cells

View full text Add to dashboard Cite

Fe 0.5 TiOPO /C composite was used as anode material for LIB and exhibits excellent cycling performance when the electrode is cycled in two different voltage ranges [3.0-1.3V] and [3.0-0.02V] where different insertion mechanisms were involved. A detailed in situ XANES spectroscopy study coupled to the electrochemical analyses, clearly established that the structure of Fe 0.5 TiOPO 4 /C electrode materials is preserved when cycled between 3.0 and 1.3V. Furthermore, a formation of new phase at the end of first discharge was evidenced, with a reversible capacity of 100 mAhg-1 after 50 cycles at C/5 rate. At highly lithiated states, [3.0-0.02V] voltage range, a reduction-decomposition reaction highlights the Liinsertion/extraction behaviors, and low phase crystallinity is observed during cycling, in addition an excellent rate behavior and a reversible capacity of 250 mAhg-1 can still be maintained after 50 cycles at high cycling rate 5C.

show abstract

Reaction mechanisms of tridymite iron phosphate with lithium ions in the low-voltage range

Cited by 11 publications

References 35 publications

Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon

Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon

Alluaudite Na₂Co₂Fe(PO₄)₃as an electroactive material for sodium ion batteries

Toward understanding the lithiation/delithiation process in Fe0.5TiOPO4/C electrode material for lithium-ion batteries

Contact Info

Product

Resources

About

Reaction mechanisms of tridymite iron phosphate with lithium ions in the low-voltage range

Cited by 11 publications

References 35 publications

Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon

Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon

Alluaudite Na2Co2Fe(PO4)3as an electroactive material for sodium ion batteries

Toward understanding the lithiation/delithiation process in Fe0.5TiOPO4/C electrode material for lithium-ion batteries

Contact Info

Product

Resources

About

Alluaudite Na₂Co₂Fe(PO₄)₃as an electroactive material for sodium ion batteries