Small
·
2024
·
IF 13
Haotian Yan,Dandan Chai,Xiang Li,Yongzhu Fu
O3-type cathodes with sufficient Na content are considered as promising candidates for sodium-ion batteries (SIBs). However, these cathodes suffer from insufficient utilization of the active elements, restraining the delivered capacity. In this work, a high entropy strategy is applied to a typical O3 cathode NaLi 0.1 Ni 0.35 Mn 0.55 O 2 (NLNM), forming a high entropy oxide NaLi 0.1 Ni 0.15 Cu 0.1 Mg 0.1 Ti 0.2 Mn 0.35 O 2 (Na-HE). Results show that the active elements are fully exploited in Na-HE, with a two-electron reaction by Ni 2+/4+ (further extended to Cu redox and even oxygen redox), vastly different from a one-electron reaction of Ni 2+/3+ in NLNM. The full utilization of the active elements dramatically improves the output capacity of the cathode (122.6 mAh g −1 of Na-HE versus 81 mAh g −1 of NLNM). Moreover, the detrimental phase transition is well suppressed in Na-HE. The cathode exhibits high capacity retention of 88.7% after 100 cycles at 130 mA g −1 , compared to only 36.4% for NLNM. These findings provide new insight for the design of new cathode materials for SIBs with high energy density and robust stability.
研究领域:
材料科学
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电化学
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电池技术
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2025
·
IF 26
Hongwei Bi,Xia Sun,Boyang Zhao,Ruiyi Li,Yongguang Zhang,Xiaoen Wang,Meng Zhang,Dan Luo,Zhongwei Chen
Na-ion layered oxides have attracted considerable interest due to their structural and electrochemical similarities to Li-ion counterparts, positioning them as promising cathode materials for sustainable energy storage. However, O3-type Na-ion layered oxides experience severe structural distortions and phase transitions during electrochemical cycling, which significantly deteriorate battery performance. In this study, an ultra-stable O3-type high-entropy doping cathode material is developed, NaNi 0.3 Mn 0.5 Fe 0.05 Li 0.05 Ti 0.05 Cu 0.05 O 2 (NMFLTC), for high-performance Na-ion battery. By partially substituted Ni of NaNi 0.5 Mn 0.5 O 2 (NM) with Fe, Li, Ti, and Cu, Na + diffusion and maintained the structural integrity of NMFLTC is successfully enhanced through the in situ formation of a high-entropy rock salt phase on the surface of the cathode material. This modification not only protects the cathode from structural degradation but also effectively mitigates phase transitions during cycling, leading to favored sodiation/de-sodiation electrochemistry and enhanced structure stability. Attributed to its structural superiorities, the high-entropy doping layered oxide cathode maintains 85.9% and 73.7% capacity retention at 0.1 C and 0.3 C after 200 and 600 cycles, respectively, which marks a significant improvement over traditional undoped NM cathodes. The proposed facile synthesis strategy enables the high entropy cathode material with possibility for large scale production, holding great promises to be utilized for practicalization.
研究领域:
储能
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材料科学
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电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Liling Dai,Hao Li,Wanli Wei,Tonghui Xu,Wenwen Xue,Ya-Jun Cheng,Yonggao Xia
O3-type NaNi 1/3 Fe 1/3 Mn 1/3 O 2 is considered as one of the most promising cathode candidates for sodium-ion batteries due to its high specific density and low cost. However, rapid capacity degradation and sluggish diffusion kinetics , caused by structural distortions and irreversible phase transitions, present significant challenges to its commercial application. In this study, we design a series of O3-NaNi 1/3-x Fe 1/3 Mn 1/3 Al x O 2 cathodes with varying Al 3+ doping concentrations, synthesized through a one-step liquid-phase modified precursor method followed by post-calcination. Notably, an optimal level of Al 3+ substitution at the transition metal sites significantly enhances the structural stability during long cycling. However, excessive Al doping at the Na-site hampers sodium-ions diffusion, thereby limiting the rate performance. The optimal performance is achieved with the O3-NaNi 1/3-0.005 Fe 1/3 Mn 1/3 Al 0.005 O 2 cathode, which exhibits remarkable overall electrochemical performance including a high specific capacity of 151 mAh g -1 at 1 C, superior cycle stability with 85 % capacity retention after 150 cycles in a half cell, and improved rate performance (74 mAh g -1 at 10 C). This work provides valuable insights into the behavior of inactive element substitution, offering a pathway for the development of long-cycle life O3-type oxide cathodes and contributing to novel materials design strategies.
研究领域:
材料科学
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电化学
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能源存储
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无机化学
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固体化学
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电池技术
✓ 已验证
产品关联
DOI
高影响因子
Carbon Energy
·
2024
·Vol. 7
·期 1
·e627
·
IF 19.5
Yingcong Liu,Xing Zhou,Dongwei He,Xiaowei Liu,Chao Yang,Dawei Xu,Meilong Wang,Ruitao Sun,Bin Zhang,Jingjing Xie,Jin Han,Wen Chen,Ya You
The O3-type layered cathode with high Ni content has attracted much attention because of its high capacity and simple synthesis process. However, surface side reaction and O3–P3 phase transitions would occur during Na + insertion/extraction, resulting in unsatisfying electrochemical performance. Herein, O3-Na[Ni 0.6 Co 0.2 Mn 0.2 ]O 2 (NNCM622) cathode is modified by a NaTiO x coating layer in a wet chemistry method, which reduces the parasitic reaction and facilitates Na + migration. Simultaneously, the partially doped Ti improves structural stability by restraining the irreversible multiple-phase transition. As a result, the modified NNCM622 cathode obtains a high specific capacity of 143.4 mAh g −1 and an improved capacity retention of 69% after 300 cycles. Our work offers new prospects for stabilizing the NNCM622 cathode with a feasible coating strategy.
研究领域:
材料科学
·
电化学
·
储能
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Weidong Li,Qiuyi Chen,Dongyun Zhang,Chen Fang,Song Nian,Wenxu Wang,Cong Xu,Chengkang Chang
Aiming for promoting the capacity and cycling stability of O3-type NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM), the cathode material of sodium ion batteries (SIBs) with the most potential for industrialization, Na(Ni 1/3 Fe 1/3 Mn 1/3 ) 0.99 Mo 0.01 O 1.99 F 0.01 (NFM-MoF), Na(Ni 1/3 Fe 1/3 Mn 1/3 ) 0.99 Mo 0.01 O 2 (NFM-Mo) and NaNi 1/3 Fe 1/3 Mn 1/3 O 1.99 F 0.01 (NFM-F) were successfully synthesized by solid phase method. The electrochemical performance of the doped samples was compared with that of the pristine NFM. The mechanism of the single- or dual-doping was explored by XRD Rietveld refinement and XPS. The NFM-MoF exhibits the highest initial specific discharge capacity of 137mAhg −1 at 1 C with a retention of 91.97% after 100 cycles and the smallest polarization (0.32 V), which could be contributed to the highest Ni 2+ content and highest D Na + (7.335 ×10 −13 cm 2 ·s −1 ) caused by the synergistic effect of Mo and F dual-doping. The highest Fe 3+ content in the NFM-Mo leads to the higher initial discharge capacity of 1 36 mAhg −1 at 1 C with a relative lower retention of 83.38%, which is due to the structure instability resulting from Fe migration and the lowest Mn content, than that of the NFM-F (85.31%). It illustrates that the Mn 4+ plays a crucial role in stabilizing the structure during Na + migrating. The superiority of the discharge capacity of the NFM-Mo become narrow with rates rise, due to its lower D Na + (4.229 ×10 −13 cm 2 ·s −1 ) than that of the NFM-F D Na + (5.681 ×10 −13 cm 2 ·s −1 ). It verifies that it is a diffusion control process at high rates. Mo and F dual-doping in NFM was proved to amplify the benefit of Ni 2+ increasing, meanwhile restrain undesirable Fe increasing due to the synergistic effect.
研究领域:
材料科学
·
电化学
·
储能技术
·
无机化学
·
固体物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）