Journal of Materials Chemistry A
·
2025
·Vol. 13
·期 38
·32562-32576
·
IF 9.5
Chenshuo Yuan,Dongwang Feng,Hui Ye,Pengkai Shan,Lin Ge,Han Chen,Yifeng Zheng,Sheng Cui
Reversible solid oxide cells (RSOCs) represent a promising technology for efficient energy conversion and storage. However, the performance is often limited by the sluggish oxygen kinetics and poor structural stability of the air electrode. The cobalt-free Bi0.5Sr0.5FeO3−δ (BSF) air electrode exhibits a comparatively desirable performance and is expected to be further optimized. Herein, we propose a B-site co-doping strategy by incorporating high valence Nb5+ and Ta5+ into BSF to synergistically optimize the oxygen transport capacity and surface reactivity. The optimized Bi0.5Sr0.5Fe0.8Nb0.1Ta0.1O3−δ (BSFN0.1T0.1) demonstrates exceptional oxygen ion diffusivity (Dchem = 4.378 × 10−4 cm2 s−1) and exchange kinetics (Kchem = 1.330 × 10−3 cm s−1), leading to a 69% reduction in polarization resistance (from 0.195 to 0.06 Ω cm2) at 750 °C. Notably, the BSFN0.1T0.1 air electrode maintains stable performance under 3–10% CO2 atmosphere, demonstrating superior CO2 tolerance. In fuel cell mode, the single cell delivers a peak power density of 616 mW cm−2 (98% enhancement over BSF) at 750 °C. In electrolysis cell mode, a current density of 1370 mA cm−2 is obtained at 750 °C and 1.5 V in 70% CO2/30% CO atmosphere (116% enhancement over BSF). The synergistic effect of Nb5+ and Ta5+ co-doping arises from their similar ionic radii, stable high valence states, and electronegativity differences, which stabilize the perovskite lattice and facilitate oxygen migration, thereby optimizing oxygen reduction/evolution reaction (ORR/OER) activity and electrochemical performance. This work provides a rational design strategy for advanced RSOC air electrodes.
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DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Steven Hu,Xinghui Liang,Huimin Yuan,Zhenning Xu,Jun Wang,Hai Liu,Kaihua Xu,Xing Ou
The development of Co-free ultrahigh-Ni (Ni > 0.9) layered oxide cathode materials holds immense promise for addressing electric vehicle range limitations and cost efficiency, though substantial obstacles persist in structural durability, thermal stability, and safety. To concurrently enhance the structural integrity and interfacial stability of LiNi 0.95 Mn 0.05 O 2 , a dual-functional co-regulation strategy integrating Zr/Al bulk doping with Li 6 Zr 2 O 7 surface coating is implemented. Controlled Zr 4+ /Al 3+ co-incorporation expands interlayer spacing, strengthens transition metal–oxygen bonding, and stabilizes the oxygen framework, thereby improving Li + diffusion kinetics while suppressing cation disorder. Concurrently, the epitaxially Li 6 Zr 2 O 7 coating effectively passivates the surface by eliminating residual lithium species, inhibiting grain coarsening, and suppressing interfacial side reactions. These coupled bulk-surface modifications synergistically inhibit mechanical stress-induced crack propagation and deleterious phase transformations. Therefore, the optimized cathode achieves 96.9% capacity retention after 100 cycles at 1 C, while maintaining stable operation under extreme electrochemical conditions (4.5 V cutoff voltage) and thermal extremes (−10 °C/60 °C). This work demonstrates a synergistic modification paradigm for designing robust ultrahigh-Ni cathodes, thereby propelling the advancement of next-generation high-energy density lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
储能
·
电池技术
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DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-11
·
IF 12.121
Liu Wei,Li Jinxing,Li Wenting,Xu Hanying,Zhang Chao,Qiu Xinping
The low Coulombic efficiency during cycling hinders the application of Cobalt-free lithium-rich materials in lithium-ion batteries. Here we demonstrated that the dissolution of iron, rather than traditionally acknowledged manganese, is mainly responsible for the low Coulombic efficiency of the iron-substituted cobalt-free lithium-rich material. Besides, we presented an approach to inhibit the dissolution of transition metal ions by using concentrated electrolytes. We found that the cathode electrolyte interphase (CEI) layer formed in the concentrated electrolyte is a uniform and robust LiF-rich CEI, which is a sharp contrast with the uneven and fragile organic-rich CEI formed in the dilute electrolyte. The LiF-rich CEI not only effectively inhibits the dissolution of TMs but also stabilizes the cathode structure. The Coulombic efficiency, cycling stability, rate performance, and safety of the Fe-substituted cobalt-free lithium-rich cathode material in the concentrated electrolyte have been improved tremendously.
研究领域:
材料科学
·
电化学
·
能源存储
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Bao Zhang,Yongkang Liu,Yunfeng Gu,Ziliang Feng,Enfeng Zhang,Peng Luo,Quanyi Zhang,Peng Dong,Yingjie Zhang,Yannan Zhang
Spinel lithium manganate (LiMn 2 O 4 ) is considered a highly promising cobalt-free cathode material for lithium-ion batteries (LIBs) owing to its three-dimensional Li-ion diffusion channels and the abundance of manganese. However, its practical applications are limited due to the substantial capacity deterioration induced by the Jahn-Teller effect and interfacial instability with the organic electrolyte. In this work, we propose a polyanion-based surface engineering strategy that enables simultaneous doping and the formation of a protective coating on the LiMn 2 O 4 cathode. Boric acid surface modification can selectively stabilize the MnO₆ octahedron, while effectively suppressing manganese dissolution and interfacial side reactions. Additionally, the partial surface boron component reacts with PF 6 − in the electrolyte to form thermodynamically stable BF 4 − , which reduces the generation of HF in the electrolyte and stabilizes the cathode electrolyte interphase (CEI). Therefore, the modified BO3-LMO exhibits remarkable cycling stability, with a capacity retention rate of 80.6 % after 900 cycles at 1C, which is significantly superior to that of the unmodified LMO (61.1 %). Additionally, the BO3-LMO demonstrates excellent rate capability and thermal stability, retaining high performance even at elevated temperatures (55 °C) and under high-rate operation (5C). Through a combination of advanced characterization techniques—such as XRD refinement, XPS, HR-TEM and density functional theory calculations, we uncover the origins of the improved electrochemical stability after surface modification. The BO3-LMO demonstrates a higher density of states at the Fermi level, stronger Mn O electron bonding, and a lower lithium-ion diffusion energy barrier. This integrated strategy not only solves the interfacial instability and structural degradation challenges but also establishes a scalable strategy for designing high-performance, cobalt-free spinel manganese-based lithium-ion batteries (LIBs).
研究领域:
材料科学
·
电化学
·
储能技术
·
表面工程
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）