Charge Localization in the Lithium Iron Phosphate Li3Fe2(PO4)3 at High Voltages in Lithium‐Ion Batteries

Younesi, Reza; Christiansen, Ane Sælland; Loftager, Simon; Garcı́a-Lastra, J. M.; Vegge, Tejs; Norby, Poul; Holtappels, Peter

doi:10.1002/cssc.201500752

Cited by 9 publications

(9 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The O 1s spectra of the lithiated sample also display a corresponding peak at about 534 eV, which is equivalent to the energy of the C−O bond. 23 A similar behavior was observed by Song et al 24 and attributed to adsorption/desorption of SEI/ electrolyte decomposition species during cycling. That bulk material is clearly detected at a photon energy of 2005 eV, meaning that the SEI is not more than 20 nm thick (assuming that the SEI is a compact layer).…”

Section: ■ Results and Discussionsupporting

confidence: 73%

See 1 more Smart Citation

Manganese in the SEI Layer of Li₄Ti₅O₁₂ Studied by Combined NEXAFS and HAXPES Techniques

et al. 2016

Self Cite

View full text Add to dashboard Cite

A combination of hard X-ray photoelectron spectroscopy (HAXPES) and near edge X-ray absorption fine structure (NEXAFS) are here used to investigate the presence and chemical state of crossover manganese deposited on Li-ion battery anodes. The synchrotron-based experimental techniquesusing HAXPES and NEXAFS analysis on the same sample in one analysis chamberenabled us to acquire complementary sets of information. The Mn crossover and its influence on the anode interfacial chemistry has been a topic of controversy in the literature. Cells comprising lithium manganese oxide (LiMn2O4, LMO) cathodes and lithium titanate (Li4Ti5O12, LTO) anodes were investigated using LP40 (1 M LiPF6, EC:DEC 1:1) electrolyte. LTO electrodes at lithiated, delithiated, and open circuit voltage (OCV-stored) states were analyzed to investigate the potential dependency of the manganese oxidation state. It was primarily found that a solid surface layer was formed on the LTO electrode and that this layer contains deposited Mn from the cathode. The results revealed that manganese is present in the ionic state, independent of the lithiation of the LTO electrode. The chemical environment of the deposited manganese could not be assigned to simple compounds such as fluorides or oxides, indicating that the state of manganese is in a more complex form.

show abstract

Section: ■ Results and Discussionsupporting

confidence: 73%

“…In the carbon spectra, there are three major peaks in the pristine sample at the binding energies of 284.5 eV, 286.8 and 291.6 eV, which are designated to C−C, −CH 2 −CF 2 , and −CF 2 bonds, respectively. 23 There is also a minor contribution at 294 eV from CF 3 groups in the Kynar binder.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Manganese in the SEI Layer of Li₄Ti₅O₁₂ Studied by Combined NEXAFS and HAXPES Techniques

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…[29] The mixed Mn valences can be introduced through oxygen vacancies, [40,41] controlled doping, [41,42] addition of an electronegative material, [43,44] or by intercalation of electrolyte ions inside the a-MnO 2 tunnels. [45][46][47] Oxygenv acancies are introduced during synthesis under reducing conditions;h owever,i ti sh ighlyu nlikely that oxygen vacancies at the surface of a-MnO 2 can withstand the highly oxidizingO ER conditions during long-term operation. [48] The work is organized in the following way.F irst, we compute bulk properties (magnetic structure and lattice constants) and make the (110) and (100) slabs.…”

Section: Introductionmentioning

confidence: 99%

“…A more detailed discussion of the catalytic role of Mn 3+ is provided in a recent review article . The mixed Mn valences can be introduced through oxygen vacancies, controlled doping, addition of an electronegative material, or by intercalation of electrolyte ions inside the α‐MnO 2 tunnels . Oxygen vacancies are introduced during synthesis under reducing conditions; however, it is highly unlikely that oxygen vacancies at the surface of α‐MnO 2 can withstand the highly oxidizing OER conditions during long‐term operation …”

Section: Introductionmentioning

confidence: 99%

Computational Screening of Doped α‐MnO₂ Catalysts for the Oxygen Evolution Reaction

2018

Self Cite

View full text Add to dashboard Cite

Minimizing energy and materials costs for driving the oxygen evolution reaction (OER) is paramount for the commercialization of water electrolysis cells and rechargeable metal-air batteries. Structural stability, catalytic activity, and electronic conductivity of pure and doped α-MnO for the OER are studied using density functional theory calculations. As model surfaces, we investigate the (110) and (100) facets, on which three possible active sites are identified: a coordination unsaturated, a bridge, and a bulk site. For pure and Cr-, Fe-, Co-, Ni-, Cu-, Zn-, Cd-, Mg-, Al-, Ga-, In-, Sc-, Ru-, Rh-, Ir-, Pd-, Pt-, Ti-, Zr-, Nb-, and Sn-doped α-MnO , the preferred valence at each site is imposed by adding/subtracting electron donors (hydrogen atoms) and electron acceptors (hydroxy groups). From a subset of stable dopants, Pd-doped α-MnO is identified as the best catalyst and the only material that can outperform pristine α-MnO . Different approaches to increase the bulk electron conductivity of semiconducting α-MnO are discussed.

show abstract

“…This finding recalls the recent observation where a similar oxygen-polaronic effect was found in another type of polyanionic material Li 3 Fe 2 (PO 4 ) 3 during delithiation, while in Li 3 V 2 (PO 4 ) 3 , the oxidation takes place on the vanadium ions. 57 A detailed discussion on the evolution of energy orbitals during delithiation explaining the above differences of the redox activity for the Li (2−x) TMSiO 4 family is provided in Supporting Information Notes 5 and 6.…”

mentioning

confidence: 99%

Mechanism of Exact Transition between Cationic and Anionic Redox Activities in Cathode Material Li₂FeSiO₄

Zheng

Teng

Yang

et al. 2018

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

The discovery of anion redox activity is promising for boosting the capacity of lithium-ion battery (LIB) cathodes. However, fundamental understanding of the mechanisms that trigger the anionic redox is still lacking. Here, using hybrid density functional study combined with experimental soft X-ray absorption spectroscopy (sXAS) measurements, we unambiguously proved thata widely-studied cathode material for LIBs, performs sequent cationic and anionic redox activity through delithiation. Specifically, Fe 2+ is oxidized to Fe 3+ during the first Li-ion extraction per formula unit (f.u.), while the second Li-ion extraction triggered the oxygen redox exclusively. The transition between cationic and anionic redox activities happens exactly at LiFeSiO 4 , with electron and hole polaronic behaviors, respectively. For other polyanionic transition-metal (TM) materials in this family, while Li 2 NiSiO 4 shows similar sequent redox activity as Li 2 FeSiO 4 , Li 2 MnSiO 4 shows the multiple cationic redox (Mn 2+ -Mn 4+ ) during the whole delithiation, and Li 2 CoSiO 4 shows a simultaneous cationic and anionic redox. The present finding not only provides new insights into the oxygen redox activity in polyanionic compounds for rechargeable batteries, but also sheds light on the future design of high-capacity rechargeable batteries. 2 3

show abstract

Charge Localization in the Lithium Iron Phosphate Li₃Fe₂(PO₄)₃ at High Voltages in Lithium‐Ion Batteries

Cited by 9 publications

References 21 publications

Manganese in the SEI Layer of Li₄Ti₅O₁₂ Studied by Combined NEXAFS and HAXPES Techniques

Manganese in the SEI Layer of Li₄Ti₅O₁₂ Studied by Combined NEXAFS and HAXPES Techniques

Computational Screening of Doped α‐MnO₂ Catalysts for the Oxygen Evolution Reaction

Mechanism of Exact Transition between Cationic and Anionic Redox Activities in Cathode Material Li₂FeSiO₄

Contact Info

Product

Resources

About

Charge Localization in the Lithium Iron Phosphate Li3Fe2(PO4)3 at High Voltages in Lithium‐Ion Batteries

Cited by 9 publications

References 21 publications

Manganese in the SEI Layer of Li4Ti5O12 Studied by Combined NEXAFS and HAXPES Techniques

Manganese in the SEI Layer of Li4Ti5O12 Studied by Combined NEXAFS and HAXPES Techniques

Computational Screening of Doped α‐MnO2 Catalysts for the Oxygen Evolution Reaction

Mechanism of Exact Transition between Cationic and Anionic Redox Activities in Cathode Material Li2FeSiO4

Contact Info

Product

Resources

About

Charge Localization in the Lithium Iron Phosphate Li₃Fe₂(PO₄)₃ at High Voltages in Lithium‐Ion Batteries

Manganese in the SEI Layer of Li₄Ti₅O₁₂ Studied by Combined NEXAFS and HAXPES Techniques

Manganese in the SEI Layer of Li₄Ti₅O₁₂ Studied by Combined NEXAFS and HAXPES Techniques

Computational Screening of Doped α‐MnO₂ Catalysts for the Oxygen Evolution Reaction

Mechanism of Exact Transition between Cationic and Anionic Redox Activities in Cathode Material Li₂FeSiO₄