Exploring the influence of iron substitution in lithium rich layered oxides Li₂Ru_1−xFe_xO₃: triggering the anionic redox reaction

Abstract

The partial substitution of Ru with Fe in Li2RuO3 stabilises the layered structure during cycling, leading to a stable capacity of ∼250 mA h g–1.

Inhibition of oxygen dimerization by local symmetry tuning in Li-rich layered oxides for improved stability

“…11a , the capacity retention of ID-Li 2 RuO 3 is significantly higher than that of R-Li 2 RuO 3 in all cases, even when the initial specific discharge capacity of ID-Li 2 RuO 3 (260 mAh g –1 for 2.0–5.0 V) turns higher than that of R-Li 2 RuO 3 (246 mAh g –1 for 2.0–4.2 V). The relatively low capacity retention of R-Li 2 RuO 3 is consistent with previous literature reports 44 – 47 . Thus, we conclude that the ID-Li 2 RuO 3 electrode is more stable than the R-Li 2 RuO 3 electrode upon cycling, as predicted above.…”

A Cobalt‐Free Li(Li0.16Ni0.19Fe0.18Mn0.46)O2 Cathode for Lithium‐Ion Batteries with Anionic Redox Reactions

“…In addition, the plot of the average discharge potential is displayed in Figure d. A high discharge potential, which was above 3.63 V (vs. Li/Li + ) at the first discharge, was maintained at 3.38 V after 100 cycles, indicating a suppressed potential fade. The discharge potential was much higher than other Li‐rich materials owing to Fe substitution …”

“…demonstrated that the reversible capacity of Li 1+ x Fe y Mn 1− x − y O 2 is generated from the Fe 3+ /Fe 4+ redox couple at approximately 4 V, which was further confirmed by the 57 Fe Mössbauer spectrum . Tarascon and co‐workers also found that in Li 4 FeSbO 6 and Li 2 Ru 1‐ x Fe x O 3 , Fe 3+ can be oxidized to Fe 4+ , which was accompanied by the oxidation of O 2− to O 2 2− during delithiation. Although most observations verify the oxidation of Fe 3+ , a clear explanation of the redox mechanism for either Fe or O in the Ni‐, Fe‐, and Mn‐containing Li‐rich materials is still lacking.…”

“…The dischargep otential was much highert han other Li-rich materials [22] owing to Fe substitution. [12] Thermals tability is one of the mostf undamentalp roperties required for LIBs in EVs. In this work, differential scanning calorimetry (DSC) was performedt oe xamine the thermals tability of delithiated NFM (after it was first charged to 4.8 V).…”

The application of synchrotron X-ray techniques to the study of rechargeable batteries

“…The details of the redox reaction mechanism in Li-rich x Li 2 MnO 3 •(1-x )LiMO 2 cathode is still ambiguous and under intense discussion, although it is generally accepted that the anionic (O 2 − ) redox processes plays an important role. Combing oxygen K-edge and transition metal l -edges soft XAS and in situ hard XAS, the charge compensation mechanism in this system has been extensively investigated [173][174][175][176][177][178] . Typically reversibly shifts between the charged/discharged states are observed for Ni and Co l -edge XAS spectra, indicating that the Ni and Co ions reversibly participate in the charge compensation.…”