Tunnel-structured Na0.66[Mn0.66Ti0.34]O2-F  (x&lt;0.1) cathode for high performance sodium-ion batteries

Wang, Qin Chao; Qiu, Qi; Xiao, Na; Fu, Zheng; Wu, Xinming; Yang, Xiao Qing; Zhou, Yong Ning

doi:10.1016/j.ensm.2018.03.007

Cited by 35 publications

(24 citation statements)

References 31 publications

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“…When the current density returns to 0.5 C, the maximum discharge capacity of the [NL]MO electrode is recovered to 123.0 mA h g –1 , due to the activation of spinel LiMn 2 O 4 . Remarkably, compared with other cathode materials incorporating the tunnel‐type Na 0.44 MnO 2 and its analogs, [ 12–14,16–19,23,29,41–47 ] the [NL][ML]O composite achieves the highest rate capability; refer to Figure 3d.…”

Section: Resultsmentioning

confidence: 99%

“…During the Na + extraction process, most of the diffraction peaks appear at relatively higher 2θ angles (relative to the peaks obtained in their fresh state), which could be associated with the shrinkage of the unit cell caused by the decrease in electrostatic repulsion between adjacent O atoms after Na + extraction. [ 47 ] A new Na 2 Mn 5 O 10 phase is observed upon Na + extraction in Li‐free samples, indicating incomplete desodiation and the formation of an intermediate phase. In contrast, at the end of the first charge, the major diffraction peaks of [NL][ML]O appear at relatively higher 2θ angles without any observable new peaks, indicating that the active material undergoes a solution reaction.…”

Section: Resultsmentioning

confidence: 99%

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Lithium‐Substituted Tunnel/Spinel Heterostructured Cathode Material for High‐Performance Sodium‐Ion Batteries

Liang

Kim

Jung

et al. 2020

Adv Funct Materials

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Sodium manganese oxides as promising cathode materials for sodium‐ion batteries (SIBs) have attracted interest owing to their abundant resources and potential low cost. However, their practical application is hindered due to the manganese disproportionation associated with Mn3+, resulting in rapid capacity decline and poor rate capability. Herein, a Li‐substituted, tunnel/spinel heterostructured cathode is successfully synthesized for addressing these limitations. The Li dopant acts as a pillar inhibiting unfavorable multiphase transformation, improving the structural reversibility, and sodium storage performance of the cathode. Meanwhile, the tunnel/spinel heterostructure provides 3D Na+ diffusion channels to effectively enhance the redox reaction kinetics. The optimized [Na0.396Li0.044][Mn0.97Li0.03]O2 composite delivers an excellent rate performance with a reversible capacity of 97.0 mA h g–1 at 15 C, corresponding to 82.5% of the capacity at 0.1 C, and a promising cycling stability over 1200 cycles with remarkable capacity retention of 81.0% at 10 C. Moreover, by combining with hard carbon anodes, the full cell demonstrates a high specific capacity and favorable cyclability. After 200 cycles, the cell provides 105.0 mA h g–1 at 1 C, demonstrating the potential of the cathode for practical applications. This strategy might apply to other sodium‐deficient cathode materials and inform their strategic design.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Lithium‐Substituted Tunnel/Spinel Heterostructured Cathode Material for High‐Performance Sodium‐Ion Batteries

Liang

Kim

Jung

et al. 2020

Adv Funct Materials

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“…Figure 8a shows the CV curves at various scan rates ( v ) from 0.1 to 1.0 mV s –1 with clear redox peaks, indicating good reaction kinetics during the successive charge/discharge processes. [ 21 ] In general, with the increasing of scan rates, the peak currents ( I p ) of the oxidation and reduction peaks increase. As shown in Figure 8b, the peak currents I p shows a good linear dependence on the square root of the scan rate ( v 1/2 ) for intercalation/deintercalation process, indicating a diffusion‐controlled behavior for Na storage process.…”

Section: Resultsmentioning

confidence: 99%

“…Because of a good linear behavior of E versus τ 1/2 in Figure S13 in the Supporting Information, sodium ions diffusion coefficient can be calculated by Equation (S1) in the Supporting Information. [ 21,23 ] The voltage difference between the end of each interrupted constant current charge and the end of relaxation, defined as the overpotential, [ 15 ] can be used as an indicator of the reaction kinetics; the smaller the overpotential, the better the kinetics. In Figure 8c, the overpotential for first charge is very small and the calculated Na diffusion coefficient ( D Na+ ) decreases from 3.5 × 10 –11 to 2 × 10 –12 cm 2 s –1 when the potential increases from 2.75 to 4.2 V. However, P2‐Na 0.67 Mn 0.67 Ni 0.33 O 2 exhibits only 10 –11 to 10 –13 cm 2 s –1 diffusion coefficients of Na + during charge.…”

Section: Resultsmentioning

confidence: 99%

Tuning Sodium Occupancy Sites in P2‐Layered Cathode Material for Enhancing Electrochemical Performance

Wang

Shadike

et al. 2021

Advanced Energy Materials

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Different sodium occupancy sites in P2‐layered cathode materials can reorganize Na‐ion distribution and modify the Na+/vacancy superstructure, which have a vital impact on the Na‐ion transport and Na storage behavior during charge and discharge processes, but have not been investigated specifically and are not yet well understood. Herein, the occupancy ratio of two different Na sites (sites below transition metal ions and sites below oxygen ions along the c direction) in P2‐Na0.67[Mn0.66Ni0.33]O2 cathode is tuned successfully by inducing Sb5+ ions with strong repulsion toward Na sites right below transition metals. It is found that the decrease of Na occupancy right below transition metal ions is beneficial to the electrochemical performance of P2‐layered cathode materials, regarding cycle stability and rate capability. In situ X‐ray absorption spectroscopy reveals that the reversible Mn3.3+/Mn4+ and Ni2+/Ni3+ redox couples provide charge compensation in different voltage regions of 1.8–2.3 and 2.3–4.2 V, respectively. The transmission X‐ray microscopy confirms the uniform redox reaction over the whole electrode particle. In addition, Sb substitution can suppress the “P2‐O2” phase transition in high voltage region by preventing oxygen gliding in a–b planes, thus ensuring robust structure stability during cycling.

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“…Wang et al. [ 35 ] reported that tunnel‐structured Na 0.66 [Mn 0.66 Ti 0.34 ]O 2 cathode material exhibits enhanced electrode kinetics for Na + storage through constructing enlarged S‐shape channels by F − doping. Therefore, if active surface tuning and beneficial lattice regulation with accelerated charge transport can be achieved simultaneously in TiO 2 , it is likely to develop superior TiO 2 ‐based anodes with both large specific capacity and excellent rate performance.…”

Section: Introductionmentioning

confidence: 99%

Fluorine Triggered Surface and Lattice Regulation in Anatase TiO₂₋_xF_x Nanocrystals for Ultrafast Pseudocapacitive Sodium Storage

Sun

Zhu

et al. 2020

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Sodium‐ion batteries (SIBs) have been considered as one of the most promising secondary battery techniques for large‐scale energy storage applications. However, developing appropriate electrode materials that can satisfy the demands of long‐term cycling and high energy/power capabilities remains a challenge. Herein, a fluorine modulation strategy is reported that can trigger highly active exposed crystal facets in anatase TiO2−xFx, while simultaneously inducing improved electron transfer and Na+ diffusion via lattice regulation. When tested in SIBs, the optimized fluorine doped TiO2−xFx nanocrystals exhibit a high reversible capacity of 275 mA h g−1 at 0.05 A g−1, outstanding rate capability (delivering 129 mA h g−1 at 10 A g−1), and remarkable cycling stability with 91% capacity retained after 6000 cycles at 2 A g−1. Importantly, the optimized TiO2−xFx nanocrystals are dominated by pseudocapacitive Na+ storage, which can be attributed to the fluorine induced surface and lattice regulation, enabling ultrafast electrode kinetics.

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Tunnel-structured Na0.66[Mn0.66Ti0.34]O2-F (x<0.1) cathode for high performance sodium-ion batteries

Cited by 35 publications

References 31 publications

Lithium‐Substituted Tunnel/Spinel Heterostructured Cathode Material for High‐Performance Sodium‐Ion Batteries

Lithium‐Substituted Tunnel/Spinel Heterostructured Cathode Material for High‐Performance Sodium‐Ion Batteries

Tuning Sodium Occupancy Sites in P2‐Layered Cathode Material for Enhancing Electrochemical Performance

Fluorine Triggered Surface and Lattice Regulation in Anatase TiO₂₋_xF_x Nanocrystals for Ultrafast Pseudocapacitive Sodium Storage

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Tunnel-structured Na0.66[Mn0.66Ti0.34]O2-F (x<0.1) cathode for high performance sodium-ion batteries

Cited by 35 publications

References 31 publications

Lithium‐Substituted Tunnel/Spinel Heterostructured Cathode Material for High‐Performance Sodium‐Ion Batteries

Lithium‐Substituted Tunnel/Spinel Heterostructured Cathode Material for High‐Performance Sodium‐Ion Batteries

Tuning Sodium Occupancy Sites in P2‐Layered Cathode Material for Enhancing Electrochemical Performance

Fluorine Triggered Surface and Lattice Regulation in Anatase TiO2−xFx Nanocrystals for Ultrafast Pseudocapacitive Sodium Storage

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Product

Resources

About

Fluorine Triggered Surface and Lattice Regulation in Anatase TiO₂₋_xF_x Nanocrystals for Ultrafast Pseudocapacitive Sodium Storage