OPTICAL MATERIALS
·
2020
·
IF 2.779
Guonan Cui,Yanchun Yang,Ruilan Chen,Chengjun Zhu
Cations substitutions are known to make much significant contribution on achieving the high-quality kesterite Cu 2 ZnSn(S,Se) 4 thin films . And the optimal ratios of Mn, Ni and Co substitutions are reported to be ~0.05, belong to the low doping to reduce their defect density , which looks like to some extent the effect of Na doping. In this study, learning the research experience of alkali metal doping, we introduced the extra trace Mn 2+ ion into the precursor solution without affecting the compositions of other elements (i.e. Cu, Zn, and Sn), and the effect of trace addition on properties of the absorber layer was also studied. It was discovered that crystalline, electrical properties, and hole carrier concentration of Cu 2 ZnSn(S,Se) 4 thin films increased with an increase of Mn incorporation, and the best doping ratio of Mn/(Cu + Zn + Sn) was considered to be 0.03. In addition, the effect of extra trace Mn-doping on the film thickness and elemental compositions of Cu 2 ZnSn(S,Se) 4 absorber layer were studied in detail.
研究领域:
材料科学
·
半导体物理
·
薄膜制备
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光伏材料
·
固体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Liying Xian,Min Li,Daping Qiu,Chuang Qiu,Cheng Yue,Feng Wang,Ru Yang
Layered P-type structures are integral to most competitive cathodes for sodium-ion batteries (SIBs). However, the performance of P2-type cobalt-based layered materials is unsatisfactory owing to a low initial discharge capacity caused by Na deficiency. Here, Mn-doped Na x CoO 2 with a P3 structure is synthesized by using a modified solvent-thermal method with calcination . A structural analysis shows that partial Mn doping can effectively control P3 phase formation and increase d -layer spacing, thereby improving the diffusion of Na + . In addition, enhanced electrochemical performance is observed in optimized P3-type Na 0.26 Co 0.48 Mn 0.52 O 2 (NCMO-1), which exhibits a reversible specific capacity of 64 mAh g −1 at 3 A g −1 and a good capacity retention of 58% after 500 cycles. Furthermore, the Na-ion full cell constructed with an NCMO-1 cathode and a hard carbon anode yields a competitive energy density of 175.9 Wh kg −1 at 0.4 A g −1 with excellent cycle stability. Thus, this work provides a new viewpoint on the development of P3 structural materials with higher electrochemical performance for SIBs.
研究领域:
材料科学
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电化学
·
能源存储
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无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 4
·2887-2894
·
IF 2.22
Liu Yuan,Gu Yi-Jing,Deng Jia-Li,Luo Gui-Yang,Wu Fu-Zhong,Mai Yi,Dai Xin-Yi,Li Jun-Qi
A series of LiFe 1− x Mn x PO 4 /C composites were successfully synthesized through a simple hydrothermal method. The effects of doped Mn on their micro-structures and electrochemical performances were investigated. The XRD results indicate that Mn doping cannot change the olivine lattice type of LiFePO 4 . Appropriate Mn doping can reduce the particle size of LiFePO 4 . The electrochemical performance data show that the electrochemical performances of the composite materials are enhanced at first and then decrease as the doping amount of Mn increases. Both the CV and EIS results illustrate that a small amount of doped Mn will reduce the electrode polarization and electrochemical impedance of the samples and simultaneously improve the electrochemical performance. Among all the samples, the LiFe 0.98 Mn 0.02 PO 4 /C sample has a desirable electrochemical performance, with its specific discharge capacity reaching 156.0 mAh g −1 at a rate of 0.1 C. Even at a high rate of 5 C, it can still reach 110.0 mAh g −1 . All the results indicate that an appropriate amount of doped Mn has an emphatic effect on the electrochemical performance of LiFePO 4 /C.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
纳米材料
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Wenbin Wu,Ping Zhang,Siqi Chen,Xiaohong Liu,Guilin Feng,Meihua Zuo,Wangyan Xing,Bin Zhang,Weifeng Fan,Heng Zhang,Ping Zhang,Jie Zhang,Wei Xiang
O3 phase layered oxides are highly attractive cathode materials for sodium-ion batteries because of their high capacity and decent initial Coulombic efficiency. However, their rate capability and long cycling life are unsatisfactory due to the narrow Na + transfer channel and irreversible phase transitions of O3 phase during sodiation/desodiation process. Constructing O3/P2 multiphase structures has been proven to be an effective strategy to overcome these challenges. In this study, we synthesized bi-phasic structured O3/P2 Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 1- x Mn x O 2 ( x = 0.01, 0.02, 0.03, 0.04, 0.05) materials through Mn doping during sodiation process. Benefiting from surface P2 phase layer with the enhanced Na + transfer dynamics and high structural stability , the Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 0.98 Mn 0.02 O 2 (NFCM-M2) cathode delivers a reversible capacity of 139.1 mA h g −1 at 0.1 C, and retains 71.4 % of its original capacity after 300 cycles at 1 C. Our work provides useful guidance for designing multiphase cathodes and offers new insights into the structure-performance correlation for sodium-ion cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子