ACS Nano
·
2025
·
IF 16
Zhaowen Bai,Subash Kandasamy,Wei Wang,Rui Zhou,Zhenjie Zhang,Xuefeng Wang,Jiatu Liu,Zhenbin Wang,Guohua Chen,Qingyu Kong,Tianyi Li,Yang Ren
High-nickel layered oxides are promising cathode materials for next-generation lithium-ion batteries due to their high energy density, but their structural instability at high voltages remains a critical challenge. This study investigates how Ni migration influences phase segregation, Li/Ni antisite defect accumulation, and mechanical degradation in LiNiO2 (LNO) through a combination of synchrotron X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), transmission electron microscopy (TEM), and density functional theory (DFT) calculations. The results reveal that at high voltages, Ni migrates into tetrahedral sites, leading to the formation of coexisting R3̅m phases with distinct lattice behaviors. This phase segregation induces inhomogeneous lithium distribution, internal stress, and strain accumulation, ultimately promoting microcrack formation and accelerating structural degradation. While Ni migration is partially reversible upon discharge, continuous cycling leads to the progressive accumulation of Li/Ni antisite defects, which disrupt Li-ion transport and further destabilize the structure. The findings describe the role of bulk Ni migration in phase segregation, linking atomic-scale lattice distortions to long-term performance limitations in high-Ni cathodes. These insights suggest strategies such as selective doping to mitigate Ni migration and improve the structural stability.
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DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2023
·Vol. 35
·期 16
·2208800
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IF 29.4
Tianyang Wang,Xuan Luo,Jingjing Gao,Zhongzhu Jiang,Wei Wang,Xingcai Yang,Nan Zhou,Xiaoguang Zhu,Lei Zhang,Wenjian Lu,Wenhai Song,Hongyan Lv,Yuping Sun
Weyl semimetal T d -MoTe 2 has recently attracted much attention due to its intriguing electronic properties and potential applications in spintronics. Here, Fe-intercalated T d -Fe x MoTe 2 single crystals (0 < x < 0.15 ) are grown successfully. The electrical and thermoelectric transport results consistently demonstrate that the phase transition temperature T S is gradually suppressed with increasing x . Theoretical calculation suggests that the increased energy of the T d phase, enhanced transition barrier, and more occupied bands in 1T′ phase is responsible for the suppression in T S . In addition, a ρ α –ln T behavior induced by Kondo effect is observed with x ≥ 0.08, due to the coupling between conduction carriers and the local magnetic moments of intercalated Fe atoms. For T d -Fe 0.15 MoTe 2 , a spin-glass transition occurs at ≈10 K. The calculated band structure of T d -Fe 0.25 MoTe 2 shows that two flat bands exist near the Fermi level, which are mainly contributed by the d yz and d x 2 − y 2 ${{\rm{d}}_{{x^2} - {y^2}}}$ orbitals of the Fe atoms. Finally, the electronic phase diagram of T d -Fe x MoTe 2 is established for the first time. This work provides a new route to control the structural instability and explore exotic electronic states for transition-metal dichalcogenides.
研究领域:
凝聚态物理
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材料科学
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量子材料
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自旋电子学
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电子输运
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 13
·6191-6200
·
IF 3.3
Jiangzhi Xiong,Peng Xiao,Jian Luo,Yangjie Li,Peng Zhou,Liang Pang,Xilei Xie,Yang Li
Structural instability due to huge volume changes of silicon during charging and discharging limits its commercial applications. In this work, we prepare a novel fluorine-modified integrated silicon/carbon anode (denoted as F-SC), consisting of yolk–shell particles and hierarchical porous carbon sheets, via a simple one-step self-sacrificing strategy. This integrated structure requires no acid or base etching, making it more efficient and environmentally friendly than other template strategies. Detailed analysis of various characterization studies reveals that the well-designed structure can build a satisfactory expansion space for silicon, enhance lithium-ion reaction kinetics, offer stable interfacial contacts, and establish a three-dimensional conductive network. As a lithium-ion battery (LIB) anode, the prepared composite demonstrates a high initial coulombic efficiency (ICE) of 83.3%, a distinguished reversible capacity of 1013 mA h g−1 at 1 A g−1 after 400 cycles with an average Coulomb efficiency of 99.4% and a superior rate ability of 987 mA h g−1 at an ultrahigh rate of 5 A g−1. The reaction kinetics verify the synergy of solid-state diffusion and surface-controlled reactions. The current research can provide powerful ideas for the rapid commercialization of advanced silicon-based materials.
研究领域:
材料科学
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能源存储
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电化学
·
纳米技术
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DOI
高影响因子
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