Nanostructured LiMnO2 with Li3PO4 Integrated at the Atomic Scale for High-Energy Electrode Materials with Reversible Anionic Redox

Sawamura, Miho; Kobayakawa, Sho; Kikkawa, Jun; Sharma, Neeraj; Goonetilleke, Damian; Rawal, Aditya; Shimada, Nanaka; Yamamoto, Kentaro; Yamamoto, Rina; Zhou, Yingying; Uchimoto, Yoshiharu; Nakanishi, Koji; Mitsuhara, Kei; Ohara, Koji; Park, Jiwon; Byon, Hye Ryung; Koga, Hiroaki; Okoshi, Masaki; Ohta, Toshiaki; Yabuuchi, Naoaki

doi:10.1021/acscentsci.0c01200

Cited by 28 publications

(29 citation statements)

References 61 publications

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“…The phase stability of partially delithiated samples was evaluated by plotting the formation energies, ΔE f , using energies of fully lithiated and delithiated compositions as references. 76,66…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li₃NbO₄–NiO Binary System

et al. 2022

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Dependence on lithium-ion batteries for automobile applications is rapidly increasing. The emerging use of anionic redox can boost the energy density of batteries, but the fundamental origin of anionic redox is still under debate. Moreover, to realize anionic redox, many reported electrode materials rely on manganese ions through π-type interactions with oxygen. Here, through a systematic experimental and theoretical study on a binary system of Li 3 NbO 4 −NiO, we demonstrate for the first time the unexpectedly large contribution of oxygen to charge compensation for electrochemical oxidation in Ni-based materials. In general, for Ni-based materials, e.g., LiNiO 2 , charge compensation is achieved mainly by Ni oxidation, with a lower contribution from oxygen. In contrast, for Li 3 NbO 4 −NiO, oxygen-based charge compensation is triggered by structural disordering and σ-type interactions with nickel ions, which are associated with a unique environment for oxygen, i.e., a linear Ni−O−Ni configuration in the disordered system. Reversible anionic redox with a small hysteretic behavior was achieved for LiNi 2/3 Nb 1/3 O 2 with a cation-disordered Li/Ni arrangement. Further Li enrichment in the structure destabilizes anionic redox and leads to irreversible oxygen loss due to the disappearance of the linear Ni−O−Ni configuration and the formation of unstable Ni ions with high oxidation states. On the basis of these results, we discuss the possibility of using σ-type interactions for anionic redox to design advanced electrode materials for highenergy lithium-ion batteries.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li₃NbO₄–NiO Binary System

et al. 2022

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“…The detailed relithiation process of the DR Li 3 FeO 3.5 phase is still an open question. For other compounds, several mechanisms of the relithiation have been put forward. , However, for DR Li 3 FeO 3 , further experimental observations, especially the accurate refinement of the positions of Li and O ions upon relithiation, are still needed.…”

Section: Results and Discussionmentioning

confidence: 99%

Exploring the Origin of Anionic Redox Activity in Super Li-Rich Iron Oxide-Based High-Energy-Density Cathode Materials

2022

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Super alkali-rich materials (alkali:transition metal ratio of ≥2:1), such as Li 5 FeO 4 , exhibit the potential to realize anionic redox upon deep delithiation. Li 5 FeO 4 was shown to undergo reversible cycling between Li 4 FeO 3.5 and Li 3 FeO 3.5 with combined cation/anion redox, a remarkable capacity of 189 mAh/g, and no O 2 release. However, the impact of phase transformations on the reaction thermodynamics and the correlation between the structural changes and reaction reversibility remain unclear. In this study, we use first-principles calculations to examine the delithiation and (re)lithiation reactions of Li 5 FeO 4 . We show that the experimentally observed charge and discharge processes go through non-equilibrium pathways. Upon delithiation, the compound undergoes a phase transformation from Li 5 FeO 4 , with tetrahedrally coordinated (T d ) Fe ions, to a delithiated disordered rocksalt structure, with octahedral (O h ) Fe ions. Fe-ion migration has an asymmetric kinetic barrier that makes T d → O h migration facile, whereas the reverse process has a much larger barrier, explaining the difficulties in reaction reversibility. We further elucidate the transition metal and O redox sequences during the charge cycle and identify the complex electrochemistry associated with the dual participation of cationic redox (Fe 3+ /Fe 4+ ) and anionic redox (O 2− /O − /O 0 ). Armed with this knowledge, we conduct high-throughput screening of known alkali-rich transition metal oxides by evaluating their potential to enable reversible anionic redox, with multiple candidates proposed for further experimental trials. Our work provides a useful guide for the further development of super alkali-rich anionicredox-active electrodes for high-energy-density batteries.

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“…S1b). In contrast, nanosized and agglomerated particles are observed after MM, which is a common feature for the samples synthesized by 23,24 Additionally, the uniform distribution of O, V, and Nb ions at the nanoscale is evidenced by using a transmission electron microscope coupled with energy-dispersive X-ray spectroscopy (Fig. S2).…”

Section: Electrochemical Measurementsmentioning

confidence: 94%

Metastable and Nanosized Li1.2Nb0.2V0.6O2 for High-Energy Li-ion Batteries

Campéon

Konuma

et al. 2022

Electrochemistry

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A Li-excess cation-disordered rocksalt oxide, Li1.2Nb0.2V0.6O2, with higher theoretical capacity than traditional stoichiometric and layered oxides, is synthesized and tested as positive electrode materials for battery applications. Although Li1.2Nb0.2V0.6O2 cannot be synthesized by conventional calcination method, a single phase and metastable oxide is successfully synthesized by high-energy mechanical milling. Electrode performance of metastable and nanosized Li1.2Nb0.2V0.6O2 is significantly improved by heat treatment at 600 °C. Heat treated Li1.2Nb0.2V0.6O2 with a partial cation ordered layered structure delivers a high reversible specific capacity of 320 mAh g -1 on the basis of highly reversible two-electron redox of V ions. Moreover, inferior cyclability originating from the dissolution of V ions is successfully improved by using concentrate electrolyte solution, and over 90% capacity retention is achieved after 50 cycles. This finding opens a new way to design high-capacity metastable Li-excess oxides for advanced Li-ion batteries with higher energy density.

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Nanostructured LiMnO₂ with Li₃PO₄ Integrated at the Atomic Scale for High-Energy Electrode Materials with Reversible Anionic Redox

Cited by 28 publications

References 61 publications

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li₃NbO₄–NiO Binary System

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li₃NbO₄–NiO Binary System

Exploring the Origin of Anionic Redox Activity in Super Li-Rich Iron Oxide-Based High-Energy-Density Cathode Materials

Metastable and Nanosized Li<sub>1.2</sub>Nb<sub>0.2</sub>V<sub>0.6</sub>O<sub>2</sub> for High-Energy Li-ion Batteries

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Nanostructured LiMnO2 with Li3PO4 Integrated at the Atomic Scale for High-Energy Electrode Materials with Reversible Anionic Redox

Cited by 28 publications

References 61 publications

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li3NbO4–NiO Binary System

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li3NbO4–NiO Binary System

Exploring the Origin of Anionic Redox Activity in Super Li-Rich Iron Oxide-Based High-Energy-Density Cathode Materials

Metastable and Nanosized Li<sub>1.2</sub>Nb<sub>0.2</sub>V<sub>0.6</sub>O<sub>2</sub> for High-Energy Li-ion Batteries

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Nanostructured LiMnO₂ with Li₃PO₄ Integrated at the Atomic Scale for High-Energy Electrode Materials with Reversible Anionic Redox

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li₃NbO₄–NiO Binary System

Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li₃NbO₄–NiO Binary System