The development of low-cost and long-lasting all-climate cathode materials for the sodium ion battery has been one of the key issues for the success of large-scale energy storage. One option is the ...utilization of earth-abundant elements such as iron. Here, we synthesize a NASICON-type tuneable Na
Fe
(PO
)
(P
O
)/C nanocomposite which shows both excellent rate performance and outstanding cycling stability over more than 4400 cycles. Its air stability and all-climate properties are investigated, and its potential as the sodium host in full cells has been studied. A remarkably low volume change of 4.0% is observed. Its high sodium diffusion coefficient has been measured and analysed via first-principles calculations, and its three-dimensional sodium ion diffusion pathways are identified. Our results indicate that this low-cost and environmentally friendly Na
Fe
(PO
)
(P
O
)/C nanocomposite could be a competitive candidate material for sodium ion batteries.
Recently, room‐temperature stationary sodium‐ion batteries (SIBs) have received extensive investigations for large‐scale energy storage systems (EESs) and smart grids due to the huge natural ...abundance and low cost of sodium. The SIBs share a similar “rocking‐chair” sodium storage mechanism with lithium‐ion batteries; thus, selecting appropriate electrodes with a low cost, satisfactory electrochemical performance, and high reliability is the key point for the development for SIBs. On the other hand, the carefully chosen elements in the electrodes also largely determine the cost of SIBs. Therefore, earth‐abundant‐metal‐based compounds are ideal candidates for reducing the cost of electrodes. Among all the high‐abundance and low‐cost metal elements, cathodes containing iron and/or manganese are the most representative ones that have attracted numerous studies up till now. Herein, recent advances on both iron‐ and manganese‐based cathodes of various types, such as polyanionic, layered oxide, MXene, and spinel, are highlighted. The structure–function property for the iron‐ and manganese‐based compounds is summarized and analyzed in detail. With the participation of iron and manganese in sodium‐based cathode materials, real applications of room‐temperature SIBs in large‐scale EESs will be greatly promoted and accelerated in the near future.
State‐of‐the‐art high‐abundance and low‐cost metal‐based cathode materials for sodium‐ion batteries are comprehensively summarized and analyzed, providing a step toward the real‐life, commercial application of sodium‐ion batteries. Constructive suggestions and guidance are provided and future prospects regarding this promising field are discussed.
In this work, gold nanoparticles (AuNPs) decorated Ti
3
C
2
T
x
nanosheets (MXene/AuNPs composite) are fabricated through a self-reduction reaction of Ti
3
C
2
T
x
nanosheets with HAuCl
4
aqueous ...solution. The obtained composite is characterized as AuNPs with the diameter of about 23 nm uniformly dispersing on Ti
3
C
2
T
x
nanosheets without aggregation. The composite (MXene decorated on 4.8 wt% AuNPs) is further employed to construct supercapacitor for the first time with a higher specific capacitance of 278 F·g
−1
at 5 mV·s
−1
than that of pure Ti
3
C
2
T
x
and 95% of cyclic stability after 10,000 cycles. Furthermore, MXene/AuNPs composite symmetric supercapacitor with filter paper as separator and H
2
SO
4
as electrolyte, is assembled. The supercapacitor exhibits a high volumetric energy density of 8.82 Wh·L
−1
at a power density of 264.6 W·L
−1
and ultrafast-charging/discharging performance. It exhibits as a promising candidate applied in integrated and flexible supercapacitors.
Ions doping is regarded as an efficient approach to improve the density of calcium hexaaluminate (CA6). In this work, different amounts of N3− have been tried to dope into CA6 (CaAl12O(19-1.5x)Nx, x ...= 0-0.8) by pressureless sintering under N2 at 1750 °C using CaO, Al2O3 and Al fine powder as the raw materials. The results of the synthesized specimens characterized by XRD in combination with SEM and EDS show that a small amount of N3- up to x = 0.30 can be incorporated into CA6, increasing the thickness of the CA6 grains. Besides, first-principle calculation and structure refinement analysis suggest that the structure formula of the N-doped CA6 is CaAl12O18.58N0.28, and it is preferential for N3− to substitute O(3) ions near Al(2) in the spinel block. Such a substitution occurs in the Al-O (Al2-O3) bond parallel to c axis, and the bond lengths for tetrahedral Al-N bonds are larger than those of Al-O bonds, showing a promising potential of N3− for increasing the c-axis crystallization thickness of CA6.
Herein, we introduce a 4.0 V class high‐voltage cathode material with a newly recognized sodium superionic conductor (NASICON)‐type structure with cubic symmetry (space group P213), Na3V(PO3)3N. We ...synthesize an N‐doped graphene oxide‐wrapped Na3V(PO3)3N composite with a uniform carbon coating layer, which shows excellent rate performance and outstanding cycling stability. Its air/water stability and all‐climate performance were carefully investigated. A near‐zero volume change (ca. 0.40 %) was observed for the first time based on in situ synchrotron X‐ray diffraction, and the in situ X‐ray absorption spectra revealed the V3.2+/V4.2+ redox reaction with high reversibility. Its 3D sodium diffusion pathways were demonstrated with distinctive low energy barriers. Our results indicate that this high‐voltage NASICON‐type Na3V(PO3)3N composite is a competitive cathode material for sodium‐ion batteries and will receive more attention and studies in the future.
A new NASICON‐type high‐voltage cathode material of Na3V(PO3)3N was synthesized and its electrochemical performance was improved by carbon matrix decoration. An in‐depth investigation of the material was performed through in situ XAS and XRD, and its 3D sodium pathways were clearly identified through DFT calculations.
The first iron‐catalyzed defluorosilylation of unactivated gem‐difluoroalkenes was developed, delivering gem‐disilylated alkenes and (E)‐silylated alkenes with excellent efficiency. This protocol ...features good functional group compatibility and excellent regio‐ and stereoselectivity, enabling the late‐stage silylation of biologically relevant compounds, thus providing good opportunities for applications in medicinal chemistry. Preliminary mechanistic studies and DFT calculations reveal that a nucleophilic addition and elimination of the second C−F bond might be involved in the disilylation catalytic system, demonstrating unusual reactivity characteristics of iron catalysis.
The first iron‐catalyzed defluorosilylation of unactivated gem‐difluoroalkenes was developed, delivering the gem‐disilylated alkenes and (E)‐silylated alkenes with excellent regio‐ and stereoselectivity. Preliminary mechanistic studies and DFT calculations reveal that a nucleophilic addition and elimination of the second C−F bond might be involved in the catalytic disilylation system, demonstrating an unusual reactivity of iron catalysis.
Demands for large‐scale energy storage systems have driven the development of layered transition‐metal oxide cathodes for room‐temperature rechargeable sodium ion batteries (SIBs). Now, an abnormal ...layered‐tunnel heterostructure Na0.44Co0.1Mn0.9O2 cathode material induced by chemical element substitution is reported. By virtue of beneficial synergistic effects, this layered‐tunnel electrode shows outstanding electrochemical performance in sodium half‐cell system and excellent compatibility with hard carbon anode in sodium full‐cell system. The underlying formation process, charge compensation mechanism, phase transition, and sodium‐ion storage electrochemistry are clearly articulated and confirmed through combined analyses of in situ high‐energy X‐ray diffraction and ex situ X‐ray absorption spectroscopy as well as operando X‐ray diffraction. This crystal structure engineering regulation strategy offers a future outlook into advanced cathode materials for SIBs.
An abnormal layered‐tunnel heterostructure Na0.44Co0.1Mn0.9O2 cathode material induced by chemical element substitution is described. The crystal‐structure engineering strategy that was used gives an outlook into high‐performance sodium ion batteries.
Anti-aging is a challenging and necessary research topic. Momordica charantia L. is a common edible medicinal plant that has various pharmacological activities and is often employed in daily health ...care. However, its anti-aging effect on mice and the underlying mechanism thereof remain unclear. Our current study mainly focused on the effect of Momordica charantia L. on d-galactose-induced subacute aging in mice and explored the underlying mechanism. UHPLC-Q-Exactive Orbitrap MS was applied to qualitatively analyze the chemical components of Momordica charantia L. ethanol extract (MCE). A subacute aging mice model induced by d-galactose (d-gal) was established to investigate the anti-aging effect and potential mechanism of MCE. The learning and memory ability of aging mice was evaluated using behavioral tests. The biochemical parameters, including antioxidant enzyme activity and the accumulation of lipid peroxides in serum, were measured to explore the effect of MCE on the redox imbalance caused by aging. Pathological changes in the hippocampus were observed using hematoxylin and eosin (H&E) staining, and the levels of aging-related proteins in the PI3K/AKT signaling pathway were assessed using Western blotting. The experimental results demonstrated that a total of 14 triterpenoids were simultaneously identified in MCE. The behavioral assessments results showed that MCE can improve the learning and memory ability of subacute mice. The biochemical parameters determination results showed that MCE can improve the activity of antioxidant enzymes and decrease the accumulation of lipid peroxides in aging mice significantly. Furthermore, aging and injury in the hippocampus were ameliorated. Mechanistically, the results showed a significant upregulation in the protein expression of P-PI3K/PI3K and P-AKT/AKT (p < 0.01), as well as a significant reduction in cleaved caspase-3/caspase-3, Bax and P-mTOR/mTOR (p < 0.01). Our results confirm that MCE could restore the antioxidant status and improve cognitive impairment in aging mice, inhibit d-gal-induced apoptosis by regulating the PI3K/AKT signaling pathway, and rescue the impaired autophagy caused by mTOR overexpression, thereby exerting an anti-aging effect.
Two-dimensional MXenes have become an important material for electrochemical sensing of biomolecules due to their excellent electric properties, large surface area and hydrophilicity. However, the ...simultaneous detection of multiple biomolecules using MXene-based electrodes is still a challenge. Here, a simple solvothermal process was used to synthesis the Ti3C2Tx coated with TiO2 nanosheets (Ti3C2Tx@TiO2 NSs). The surface modification of TiO2 NSs on Ti3C2Tx can effectively reduce the self-accumulation of Ti3C2Tx and improve stability. Glassy carbon electrode was modified by Ti3C2Tx@TiO2 NSs (Ti3C2Tx@TiO2 NSs/GCE) and was able simultaneously to detect dopamine (DA), ascorbic acid (AA) and uric acid (UA). Under concentrations ranging from 200 to 1000 μM, 40 to 300 μM and 50 to 400 μM, the limit of detection (LOD) is 2.91 μM, 0.19 μM and 0.25 μM for AA, DA and UA, respectively. Furthermore, Ti3C2Tx@TiO2 NSs/GCE demonstrated remarkable stability and reliable reproducibility for the detection of AA/DA/UA.
Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high temperatures. In this study, a new porous high-entropy (La
1/6
Ce
1/6
Pr
1/6
Sm
1/6
...Eu
1/6
Gd
1/6
)PO
4
(HE (6RE
1/6
)PO
4
) ceramics was prepared by combining the high-entropy method with the pore-forming agent method and the effect of different starch contents (0–60vol%) on this ceramic properties was systematically investigated. The results show that the porous HE (6RE
1/6
)PO
4
ceramics with 60vol% starch exhibit the lowest thermal conductivity of 0.061 W·m
−1
·K
−1
at room temperature and good pore structure stability with a linear shrinkage of approximately 1.67%. Moreover, the effect of large regular spherical pores (>10 µm) on its thermal insulation performance was discussed, and an optimal thermal conductivity prediction model was screened. The superior properties of the prepared porous HE (6RE
1/6
)PO
4
ceramics allow them to be promising insulation materials in the future.
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