Small Methods
·
2018
·Vol. 3
·期 4
·1800111
·
IF 0
Yuruo Qi,Junmei Zhao,Chao Yang,Huizhou Liu,Yong-Sheng Hu
Sodium vanadium fluorophosphate, Na 3 (VO 1− x PO 4 ) 2 F 1+2 x (0 ≤ x ≤ 1), is proved to be a series of very promising cathode materials for Na-ion batteries, owing to the high operating voltage and structural stability. However, the selective preparation of phase-pure Na 3 (VO 1− x PO 4 ) 2 F 1+2 x (0 ≤ x ≤ 1) with outstanding electrochemical performance still remains a big challenge. Moreover, there are lots of discrepancies concerning the Na-storage properties, including a diversity of voltage profiles and capacities reported, based on the variety of synthetic methods. Herein, a comprehensive investigation is conducted about the fabrication of phase-pure Na 3 (VO 1− x PO 4 ) 2 F 1+2 x (0 ≤ x ≤ 1) by employing different starting materials and corresponding synthetic conditions, based on a facile low-temperature hydrothermal strategy. Results show that the pH in the reaction system may be of vital importance for the successful preparation of Na 3 (VO 1− x PO 4 ) 2 F 1+2 x (0 ≤ x ≤ 1) with special microarchitecture. Furthermore, it is found that NaH 2 PO 4 ·2H 2 O is the most appropriate phosphorus source, while VCl 3 , VOSO 4 · x H 2 O, and NH 4 VO 3 are the best choices of vanadium sources to prepare Na 3 (VO 1− x PO 4 ) 2 F 1+2 x (0 ≤ x ≤ 1) with superior Na-storage performance. This is the first time that the underlying correlations between the starting materials and the Na-storage performance, are investigated and further that guidance for the selective synthesis of phase-pure Na 3 (VO 1− x PO 4 ) 2 F 1+2 x (0 ≤ x ≤ 1) with superior performance is provided.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
Advanced Energy Materials
·
2018
·Vol. 8
·期 15
·1703217
·
IF 21.875
Panxing Bai,Yongwu He,Xiaoxi Zou,Xinxin Zhao,Peixun Xiong,Yunhua Xu
Hard carbons (HCs) are the most promising candidate anode materials for emerging Na-ion batteries (NIBs). HCs are composed of misaligned graphene sheets with plentiful nanopores and defects, imparting a complex correlation between its structure and sodium-storage behavior. The currently debated mechanism of Na + -ion insertion in HCs hinders the development of high-performance NIBs. In this article, ingenious and reliable strategies are used to elaborate the correlation between the structure and electrochemical performance and further illuminate the sodium-storage mechanism in HCs. First, filling sulfur into the micropores of HCs can remove the low-voltage plateau, providing solid evidence for its association with the pore-filling mechanism. Along with the decreased concentration of defects/heteroatoms at higher treatment temperature, the reduced sloping capacity confirms the adsorption mechanism in the sloping region. Finally, the similar sodium-insertion behaviors of HCs with ether-based and ester-based electrolytes indicate that no Na + ions intercalate between the graphene layers. The determined adsorption-pore-filling mechanism encourages the design of more efficient HC anode materials with high capacity for high-energy NIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2024
·Vol. 130
·期 7
·1-10
·
IF 2.5
Chen Wanhao,Shen Xiaowei,Huan Yunfei,Yan Chenglin,Qian Tao,Liu Xuejun
The potential application of anode-less sodium metal batteries (ALSBs) is severely affected by the irreversible depletion of sodium ions. Cathode sodium compensation (SC) additive is an effective way for sodium supplement due to its simplicity and flexibility. However, developing SC additives with no toxicity, low cost, low sensitivity to air and humidity is still a huge challenge. In this work, we propose a low-cost, environmentally friendly and air-stable organic sodium salt as sodium reservoir to compensate sodium ion, thus improving the cycle stability of ALSBs. The capacity of ALSBs with N: P as low as 0.5:1 could maintain capacity retention of 91.3% after 100 cycles with this SC additive, while the cell without this SC additive would decline to almost zero after 10 cycles. The inexpensive price and ease of preparation also make it suitable for industrialization. This work provides a realistic SC approach for improving the cycling stability for ALSBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 34
·18272-18279
·
IF 12.732
Dongmei Dai,Jinxu Qiu,Hongying Hou,Xiaojuan Wang,Siyuan Li,Bobo Cao,Xinxin Zhou,Dai-Huo Liu,Bao Wang,Bao Li
P2-layered metal oxide cathodes exhibit great promise for use in sodium ion batteries due to their unique two-dimensional tunnel structure, high energy density and high redox potential, etc. However, the inferior structural stability and irreversible phase change of P2-layered cathodes inhibit their development. The best effective strategies to improve their structural stability and sodium storage properties are via the optimization of the P2-layered tunnel structure and morphology by adjusting the Na+ contents, lithium substitution and rational element doping. Herein, the first sub-group element (Cu2+, Ag+ and Au+) doped Na0.5Li0.07Mn0.61Co0.16Ni0.16O2 cathodes were successfully prepared and systematically studied using operando X-ray powder diffraction (XRD), Rietveld refinement with corresponding Fourier electron cloud maps and the galvanostatic intermittent titration technique (GITT). These data indicate that the lattice parameters (a/b, c and V), energy barrier, and Na+ diffraction coefficient of sub-group element-doped Na0.5Li0.07Mn0.61Co0.16Ni0.16O2 cathodes are gradually improved in line with an increase in the sub-group element radii, which facilitate the kinetics of Na+ migration due to the synergistic effect between the valence and radius. Additionally, the structural stability and sodium storage mechanism of the optimized hybrid Na0.5Li0.07Mn0.6Co0.16Ni0.16Au0.01O2 electrode was revealed via operando XRD.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2023
·
IF 13.1
Fanghong Zeng,Lidan Xing,Wenguang Zhang,Zhangyating Xie,Mingzhu Liu,Xiaoyan Lin,Guangxia Tang,Changyong Mo,Weishan Li
Compared with graphite, the lower sodiation potential and larger discharge capacity of hard carbon (HC) makes it the most promising anode material for sodium-ion battery. Utilizing ether-based electrolyte rather than conventional carbonate-based electrolyte, HC achieves superior electrochemical performance. Nevertheless, the mechanism by which ether-based electrolyte improves the properties of HC is still controversial, primarily focusing on whether it forms solid electrolyte interphase (SEI) film. In this work, according to the sodium storage mechanisms in HC at low voltage (<0.1 V), including Na + -diglyme co-interaction into the carbon layer (SEI forbidden) and desolvated Na + insertion in the irregular carbon holes (SEI required), the NaPF 6 concentration in ether-based electrolyte was regulated, so as to construct a discontinuous-SEI on the surface of the HC anode, which significantly enhances the electrochemical performances of HC. Specifically, with 0.2 M NaPF 6 ether-based electrolyte, HC deliverers a discharge capacity of 459.7 mA h g −1 at 0.1 C and stays at 357.2 mA h g −1 after 500 cycles at 1 C, which is substantially higher than that of higher/lower salt concentration electrolytes.
研究领域:
电化学
·
材料科学
·
能源存储
·
电池技术
·
纳米材料
·
界面化学
·
应用物理
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
J.C. Xi,Y.F. Yuan,G.C. Cai,B.X. Wang,Y.Z. Huang,S.Y. Guo,P.F. Du
As a novel anode material for sodium-ion batteries, ultrafine Ni 0.85 Se nanoparticles encapsulated inside hollow porous carbon spheres (HPCS@Ni 0.85 Se) are prepared by impregnating Ni(NO 3 ) 2 into HPCSs, calcination and selenization, which is based on the strong capillary effect of HPCSs. Material characterization reveals that Ni 0.85 Se nanoparticles with a diameter of 5–15 nm are evenly dispersed and intimately coupled to the internal wall of HPCSs, and the content of Ni 0.85 Se reaches 52.81%. HPCSs as unique reactors and Ni 0.85 Se carriers improve electronic conductivity of Ni 0.85 Se, facilitate electrolyte penetration and storage, buffer volume variation of Ni 0.85 Se, effectively confine Ni 0.85 Se during long-term cycles. Consequently, HPCS@Ni 0.85 Se exhibits excellent cycling durability and extraordinary rate capability. High reversible capacities of 341 mA h g −1 at 1 A g −1 after 1000 cycles, 280 mA h g −1 at 5 A g −1 after 2000 cycles and 305 mA h g −1 at 10 A g −1 after 540 cycles are achieved. The reaction kinetics and Na + storage mechanism are further analyzed by galvanostatic intermittent titration technique, cyclic voltammetry and electrochemical impedance spectra measurements. Ex-situ characterizations confirm outstanding structural stability of HPCS@Ni 0.85 Se. It is demonstrated that HPCS@Ni 0.85 Se is an excellent anode material, and this unique HPCS-based nanoencapsulation structure is an effective composite strategy for transition metal selenides .
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Xianyang Li,Jiakang Qu,Zuojun Hu,Hongwei Xie,Huayi Yin
Facile synthesis methods and rich-reserve feedstocks are the keys to accelerating the scale commercial use of Sb-based anodes for sodium-ion batteries (SIBs). In this paper, we synthesize Sb/carbon nanotubes (CNTs) composite anodes by a straightforward electrochemical approach using stibnite and CNTs as feedstocks. The concentrated sodium hydrate solution profits the formation of antimony and electrons enables the solid-state electrochemical desulfurization . The low-cost stibnite can be directly obtained from the earth's crust avoiding the intermediate processes and pollution of preparing the common-used raw materials SbCl 3 and metallic Sb. CNTs provides a network for both electron and ion transport, thereby resulting in producing Sb particles anchored in the CNTs network as well as restraining the cluster of electrolytic Sb particles. The electrolytic Sb-0.5CNTs anode delivers a decent capacity of 510 mAh g −1 at 0.1 A g −1 after 200 cycles and even 425 mAh g −1 at 1 A g −1 over 100 cycles. The excellent sodium-storage performances are attributed to the unique structure of the electrolytic Sb/CNTs composite. This electrochemical desulfurization method can be expanded to prepare other metal-carbon type anodes from metal sulfides ores and carbon materials composites.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Jiapin Liu,Yun Huang,Zhixing Zhao,Wenhao Ren,Zhuangzhi Li,Chao Zou,Ling Zhao,Zhaomin Tang,Xing Li,Mingshan Wang,Yuanhua Lin,Haijun Cao
The sodium super ion conductor (NASICON) structure materials are essential for sodium-ion batteries (SIBs) due to their robust crystal structure, excellent ionic conductivity, and flexibility to regulate element and valence. However, the poor electronic conductivity and inferior energy density caused by the nature of these materials have always been obstacles to commercialization. Herein, using yeast as a template to derive NASICON structure Na3MnTi(PO4)3 (NMTP) materials (noted as Yeast@NMTP/C) is presented. The Yeast@NMTP/C material retains the microsphere morphology of the yeast template and not only controls the particle size (around 2 μm) to shorten the Na+ diffusion pathways but also improves the electronic conductivity to optimize the electrochemical kinetics. The Yeast@NMTP/C cathode delivers reversible multielectron redox reactions including Ti4+/3+, Mn3+/2+, and Mn4+/3+ and exhibits a high capacity of 108.5 mAh g–1 with a 79.2% capacity retention after 1000 cycles at a 2C rate. The sodium storage mechanism of Yeast@NMTP/C reveals that the addition of Ti4+/3+ redox plays a key role in improving the Na+ diffusion kinetics, and both solid-solution and two-phase reactions take place during the desodiation and sodiation process. Additionally, the high-rate and long-span cycle performance of Yeast@NMTP/C at 10C is ascribed to contribute to pseudocapacitance.
研究领域:
材料科学
·
电化学
·
电池技术
✓ 已验证
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）