JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Yang Yang,Honghao Deng,Liying Liu,Jiahong Pan,Ping Chen,Zhicong Shi
O3-type Cu/Fe/Mn-based layered oxides are regarded as promising cathode materials for sodium-ion batteries due to the abundance of elements in the Earth's crust and the imperative for large-scale energy storage. However, these materials still encounter some challenges, including low capacity and insufficient rate performance. In this study, Al-doped, cobalt-free, and nickel-free Na 0.9 Cu 0.18 Fe 0.3 Mn 0.52-x Al x O 2 (x = 0, 0.03, 0.05, 0.08) are successfully synthesized by using the solid-state method to introduce non-electrochemically active elements to stabilize the crystal structure and enhance the electrochemical performance. The impact of Al-doping is comprehensively analyzed by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), galvanostatic intermittent titration technique (GITT), and electrochemical impedance spectroscopy (EIS). Al-doping effectively enhances the diffusion coefficient of Na + , reduces the Jahn-Teller effect caused by Mn 3+ and mitigates the transition from O3 to P3 phase. Finally, it stops the partial phase transitions from O3 to P3, which can be found in pristine oxide without Al-doping during charge-discharge cycling. Notably, the Na 0.9 Cu 0.18 Fe 0.3 Mn 0.47 Al 0.05 O 2 electrode exhibits a reversible capacity of 123.89 mAh g −1 at 0.1 C, a capacity retention rate of 91.1 % after 200 cycles at 1 C, and a discharge capacity of 66.36 mAh g −1 at a high rate of 5 C.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Qun Huang,Sheng Xu,Lei Xiao,Pingge He,Jiatu Liu,Ying Yang,Peng Wang,Baiyun Huang,Weifeng Wei
Layered transition-metal oxides are one kind of the most promising cathode materials for sodium-ion batteries. In this study, we propose a strategy to enhance the electrochemical properties of P3-type manganese-based layered oxide cathode by introducing a small amount of layered P2 and Li–O′3 phases. Powder X-ray diffraction (PXRD) structural refinement and aberration-corrected scanning transmission electron microscopy (STEM) are performed to confirm the microstructures of different samples. PXRD refinement results show that the elevated annealing temperature leads to a partial conversion of the P3 phase to the P2 phase and the addition of lithium results in the formation of a new O′3 phase in the P3/P2-layered matrix. STEM results identify the intergrowth of P3/P2 and P3/P2/O′3 in biphasic and triphasic materials, respectively. Electron energy loss spectroscopy verifies that the alkali metal layer in the O′3 phase is occupied by the lithium ion. The intergrowth of biphasic and triphasic materials in these layered P3/P2 and P3/P2/O′3 hybrid structures brings forth a positive effect on the electrochemical properties. In particular, the formation of P3/P2/O′3-intergrown hybrid structures greatly improves the cycling stability of the P3 phase that the capacity retention of P3/P2/O′3 hybrid structures remains 78%, while capacity retention of the pure P3 phase is only 54.1% after 50 cycles at a rate of 0.2 C, and the rate performance of the P3 phase has also been enhanced.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Wei Lin,Wenxue Min,Qimeng Zhang,Shunzhang You,Song Han,Chenghao Yang
O3-type layered oxides have become a research hotspot in the development of sodium-ion batteries owing to their simple synthesis method and competitive theoretical capacity. However, their practical applications still face enormous challenges, especially concerning insufficient cyclic stability and poor kinetic performance. Herein, the Sb/Al co-doping NaNi 0.48 Mn 0.49 Sb 0.01 Al 0.02 O 2 (NMSA) material was produced via sol-gel process. Sodium-ion kinetics were investigated through Cyclic Voltammetry (CV) and Galvanostatic Intermittent Titration Technique (GITT), while the charge compensation mechanism was examined via ex-situ X-ray Photoelectron Spectroscopy (XPS). The successful doping of Al improves the stability of the transition metal oxide layer (TMO 2 ), thereby extending the cycle life of material. In-situ X-ray Diffraction (XRD) analysis reveals successful inhibition of the irreversible O3-P3 phase transition. In addition, Sb-doping increases the number of ions involved in charge compensation, thereby elevating the discharge specific capacity. Therefore, the NMSA material can provide a discharge specific capacity of 128.5 mAh g −1 at 0.1C and a capacity retention rate of 85 % after 100 cycles at 1C. Finally, the interface stability of the cycled material was studied to investigate the stability of the cathode/electrolytes interface (CEI) layer. This study provides new innovative views on proposing advanced cathode for high-energy sodium-ion batteries.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Lingfeng Shi,Ziwei Liu,Ke Li,Yanbin Ning,Shengwei Dong,Shenglu Geng,Mengjie Zhang,Yulin Ma,Geping Yin,Zhenjiang Yu,Shuaifeng Lou,Hua Huo
O3-NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathodes are promising candidates for sodium-ion batteries benefited of the high theoretical capacity. However, the inherently poor electronic conductivity limits rate performance and aggravates O3-P3 phase transition, further weakens phase transition reversibility and results in structural degradation. Herein, a localized electronic regulation strategy inspired by yttrium iron garnet (YIG) is employed to address the issue of sluggish electron transport. Specifically, Y 3+ ions are utilized to partially substitute Ni 2+ to rearrange the electronic configuration of Fe 3 d orbitals, which could trigger a transition from high-spin state ( t 2 g 3 e g 2 ) to low-spin state ( t 2 g 5 e g 0 ) as well as narrow the band gap due to the asymmetric splitting of the t 2 g ∗ band near the Fermi level. Moreover, the large ionic radius tends to construct a concentration gradient of Y 3+ , thereby generating a long-range built-in electric field. Benefiting from the improved electrical conductivity, Y0.25-NFM performs 64 mAh g −1 reversible capacity at 20 C, also the enhanced reversible phase transitions assist Y0.25-NFM maintains 80.9% of initial capacity at 1 C for 500 cycles (44.7% for baseline NFM). The thorough understanding of the dual regulatory effects for Y 3+ doping on short & long-range electronic interactions provides a novel strategy to construct outstanding layered oxide cathodes for advanced SIBs.
研究领域:
材料科学
·
电化学
·
储能技术
·
固态物理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）