Sodium‐ion batteries (SIBs), as the next‐generation high‐performance electrochemical energy storage devices, have attracted widespread attention due to their cost‐effectiveness and wide geographical ...distribution of sodium. As a crucial component of the structure of SIBs, the anode material plays a crucial role in determining its electrochemical performance. Significantly, metal phosphide exhibits remarkable application prospects as an anode material for SIBs because of its low redox potential and high theoretical capacity. However, due to volume expansion limitations and other factors, the rate and cycling performance of metal phosphides have gradually declined. To address these challenges, various viable solutions have been explored. In this paper, the recent research progress of metal phosphide materials for SIBs is systematically reviewed, including the synthesis strategy of metal phosphide, the storage mechanism of sodium ions, and the application of metal phosphide in electrochemical aspects. In addition, future challenges and opportunities based on current developments are presented.
Metal phosphide has a wide application prospect as the anode material of sodium‐ion batteries (SIBs). In this paper, the mechanism of sodium storage, the preparation method of metal phosphide, and its latest application in SIBs are reviewed. The current challenges and prospects of metal phosphide are summarized and prospected.
A simple and novel method that combines the electrospinning technology with nonaqueous sol–gel method is developed to incorporate Fe
2
O
3
nanoparticles into ZIF-8-derived nitrogen-doped highly ...porous carbon fibers (NPCFs). The size of Fe
2
O
3
nanoparticles is about 5 nm. The interfacial interaction between Fe
2
O
3
and NPCFs is investigated by thermogravimetric analysis, Raman spectrum and X-ray photoelectron energy spectrum. We found that Fe
2
O
3
nanoparticles are anchored strongly in the NPCFs through the Fe–O–C covalent bond. The impact of the Fe
2
O
3
content in the composites on electrochemical performance is also studied. When served as the flexible and free-standing anode of lithium-ion batteries (LIBs), the Fe
2
O
3
/NPCFs-66.9% exhibits superior electrochemical performance with the high discharge capacity of 1351 mA h g
−1
at 50 mA g
−1
, remarkable rate capability (337 mA h g
−1
even at 5000 mA g
−1
), and stable cycling performance (1106 mA h g
−1
after 100 cycles at 100 mA g
−1
). The excellent anodic property can be ascribed to the ultra-small size of Fe
2
O
3
nanoparticles, and the one-dimensional (1D) structure combined with the excellent electrical conductivity of NPCFs matrix. Moreover, the robust interfacial interaction Fe–O–C bond can restrain the aggregation of Fe
2
O
3
nanoparticles and accommodate the volume change. This can effectively maintain the integrity of the whole electrode during the long-term cycles. The results show that the composite may be considered as a promising anode material for advanced LIBs.
Abstract
Despite the outstanding power conversion efficiency (PCE) of perovskite solar cells (PSCs) achieved over the years, unsatisfactory stability and lead toxicity remain obstacles that limit ...their competitiveness and large‐scale practical deployment. In this study, in situ polymerizing internal encapsulation (IPIE) is developed as a holistic approach to overcome these challenges. The uniform polymer internal package layer constructed by thermally triggered cross‐linkable monomers not only solidifies the ionic perovskite crystalline by strong electron‐withdrawing/donating chemical sites, but also acts as a water penetration and ion migration barrier to prolong shelf life under harsh environments. The optimized MAPbI
3
and FAPbI
3
devices with IPIE treatment yield impressive efficiencies of 22.29% and 24.12%, respectively, accompanied by remarkably enhanced environmental and mechanical stabilities. In addition, toxic water‐soluble lead leakage is minimized by the synergetic effect of the physical encapsulation wall and chemical chelation conferred by the IPIE. Hence, this strategy provides a feasible route for preparing efficient, stable, and eco‐friendly PSCs.
In recent years, lithium‐ion batteries (LIBs) have been widely used in many fields, and research on LIBs electrode materials have attracted much attention. Among them, transition metal selenides ...(TMSs) are the most promising candidates in the next generation LIBs due to their high theoretical specific capacity and electrical conductivity. However, poor cycle stability and severe volume variation result in serious capacity decay during the charge/discharge process, limiting the practical application. In this paper, CoSe2−MnSe2 composites are synthesized via Co−Mn‐based metal‐organic framework (MOF) precursor. Meanwhile, three types of materials are successfully synthesized including CoSe2‐MnSe2@reduced graphene oxide (rGO), CoSe2‐MnSe2@polypyrrole (PPy), and CoSe2‐MnSe2/glucose (C). According to the electrochemical test results, it can be seen that the electrochemical performance of CoSe2−MnSe2 has been improved significantly. CoSe2‐MnSe2@rGO electrode materials, in particular, of which the inactivation defect sites and special carbon structure of rGO could provide more attachment points for ions. Due to the perfect combination of rGO and CoSe2−MnSe2, the CoSe2‐MnSe2@rGO composites display outstanding rate performance (1266 mA h g−1 at current densities of 100 mA g−1) and high reversible capacity (1169 after 150 cycles at 100 mA g−1). We believe that CoSe2‐MnSe2@rGO is a kind of very promising anode material.
A winning combination: CoSe2‐MnSe2 composites were synthesized via Co−Mn‐based metal‐organic framework (MOF) precursor, and used as a negative electrode for LIBs with a voltage window of 0.01‐3.0 V (vs Li/Li+). The CoSe2‐MnSe2@rGO carbon composite exhibited outstanding rate performance and high reversible capacity compared to pure CoSe2‐MnSe2, CoSe2‐MnSe2/C, and CoSe2‐MnSe2@PPy composites. As seen from the electrochemical tests, rGO is more suitable as a matrix to coat CoSe2‐MnSe2 as anode for LIBs.
Materials for lithium‐ion batteries (LIBs) with excellent electrochemical performance are of significance to meet the increasing demand for rechargeable batteries. Niobium pentoxide (Nb2O5), as an ...intercalation material with promising electrochemical properties has caught our attention. In this study, Nb2O5 nanoparticles were successfully synthesized through a classical sol‐gel process. The nanoparticles with a size of less than 5 nm were uniformly coated on carbon materials, i. e., reduced graphene oxide (rGO) and three‐dimensionally ordered macroporous (3DOM) carbon, under the same proportion, to explore which kind of carbon materials is more suitable to improve the electrochemical performance of Nb2O5 as an anode for LIBs. Nb2O5/3DOM carbon composite exhibited a superior electrochemical performance to the other two materials, where a high reversible capacity of 519 mA h g−1 could be maintained at the current density of 5.0C (C=201.7 mA g−1). Furthermore, the specific capacity of Nb2O5/3DOM carbon composite maintained 1163 mA h g−1 at the current density of 0.2C (C=201.7 mA g−1) after 100 cycles.
Nb2O5 nanoparticles and two different Nb2O5/carbon composites are synthesized by a sol‐gel process and tested as negative electrodes for lithium‐ion batteries. The Nb2O5/3DOM carbon composite exhibited superior electrochemical performance (compared to pure Nb2O5 and the Nb2O5/rGO composite). Thus, 3DOM carbon is more suitable to be a matrix to coat Nb2O5 as an anode for lithium‐ion batteries than rGO.
Luminescent organic dyes with tuning emission in widely visible gamut are still interesting challenging. Herein, we report two naphthalimide derivatives (NAPP, NAPTPA), which can output the variable ...emission colors covering the whole visible spectra from purple to far-red in aqueous solution. Both naphthalimide derivatives can exhibit bright emission in aqueous solution by introducing a phenyl ring into 4-site of naphthalimide, which acts as a π-bridge in delocalized system and not affects the intramolecular charge transfer process of naphthalimide dyes. Comparison with three analogues (NAPDMP, NAPMOP and NAPDMA), we evidenced the bright emissions in aqueous solution are from the amorphous emission different from the common crystal emission of naphthalimide dyes. We further fabricated the NAPP and NAPTPA into different nanoparticles matrixes to construct the multi-color toolbox, which could output four colors (purple, blue, green and red) in aqueous solution and yellow emission in crystal. Moreover, the white emission system was obtained through solution doping method.
A series of 4-phenyl-1,8-napthalimides were synthesized, for which the fluorescence emission color can be tuned in aqueous solution. The phenyl ring introduced into the 4-position of naphthalimide was used to elicit a bright emission of the dyes in aqueous solution. We have also achieved the modulation of emission colors from purple to far-red by incorporating the dyes with different nanoparticles. Display omitted
•A series of naphthalimides (NAPs) with phenyl ring at 4-site of the NAP core.•Enhanced emissions in aggregated state were achieved in naphthalimide dyes.•Red-emission with large Stokes shift in aggregated state was obtained.•The modulation of emission colors were achieved from purple to far-red.
Bismuth sulfide (Bi2S3) as a potential Na‐storage material relies upon its special layered structure and high volumetric capacity. However, the electrochemical activity of pure Bi2S3 is greatly ...limited during the sodiation/desodiation process. The integration of Bi2S3 with reduced graphene and a particular carbon is explored to acquire active composite anodes for sodium ion batteries (SIBs). This special carbon is based on trimesic acid (H3BTC) as a carbon source, which effectively prevents the aggregation of Bi2S3 particles in the synthesis process. Compared with other carbon sources, this type of carbon source is more likely to diffuse into the interior of the precursor hole. Hence, the Bi2S3/C indicates higher reversible capacities (368 and 314 mAh g−1 after 100 cycles and 200 cycles at 100 mA g−1) than bare Bi2S3 or Bi2S3@RGO. Thus, Bi2S3/C is considered as a prospective electrode material for rechargeable batteries.
Bismuth sulfide (Bi2S3)‐integrated carbon derived from trimesic acid (H3BTC) is investigated as a potential anode for sodium‐ion batteries. H3BTC is added as a carbon source capable of forming porous carbon and prevents the particles aggregation in the synthesis process. The Bi2S3/C hybrid with reasonable nanorod structure delivers a high reversible capacity of 368 mAh g−1 after 100 cycles.
Seawater desalination which offers an abundant and reliable source of freshwater is a promising strategy to ensure water security; however, most present desalination membranes show low porosity and ...weak mechanical properties, and typically have an inevitable trade-off dilemma between permeate flux and salt rejection. Here, we present a unique strategy to create environmentally friendly polyurethane (PU) nanofiber membranes with desirable surface wettability, stable pore structures, and robust mechanical properties for desalination via green electrospinning technique and heat pressing treatment. The incorporation of polytetrafluoroethylene (PTFE) nanoparticles and heat pressing manipulation endow the nanofiber membranes with the integrated properties of robust hydrophobicity, small pore size, and hierarchical structures by constructing micro/nano surface roughness, low energy surface, and bonding points. Strikingly, the heat pressed PU/PTFE nanofiber membranes exhibit robust mechanical strength (23.5 MPa), remarkable liquid entry pressure (79.2 kPa), and exceptional vapor permeation (3395 g m−2 d−1), achieving high permeate flux of 44 kg m−2 h−1 and salt rejection of 99.96% for seawater desalination. This work provides a powerful platform for the design and development of the next-generation nanofiber materials for various filtration and separation applications.
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•Polyurethane nanofibers were fabricated via green-solvent-based electrospinning.•The hydrophobic surfaces were obtained with polytetrafluoroethylene nanoparticles.•The mechanically stable pore structures were achieved via heat pressing treatment.•The membranes showed permeate flux (44 kg m−2 h−1) and salt rejection (99.96%).
Mesoporous SnO2 microspheres are a class of promising electron transport materials for mesoscopic perovskite solar cells, but a smooth and dense film as requested by electron transport layer is ...difficult to realize using the microspheres. Here, a series of monodispersed SnO2 microspheres with high specific surface area and good crystallinity are synthesized via a surfactant-free solvothermal method. These SnO2 microspheres showing small diameters of about 75, 110 and 200 nm with narrow size distribution are achieved by precisely controlling the crystal growth process. They are suitable for constructing the electron transport layers whose thickness is only about hundreds nanometers. Besides, as the microspheres easily slip off from the substrate during the conventional spin coating process, the spray coating method is exploited to prepare high quality electron transport layers. As a result, a power conversion efficiency of 16.85% is yielded by using the 75 nm sized SnO2 microspheres as the electron transport layers. This high power conversion efficiency is attributed to the fast electron transport and inhibited charge recombination. To further improve the charge transfer between the electron transport layer and perovskite layer, graphene quantum dots are added into the SnO2 microspheres, and a best efficiency of 17.08% is obtained.
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•SnO2 microspheres with small diameters of 75, 110 and 200 nm are synthesized.•High quality SnO2 microsphere electron transport layers are prepared by spray coating.•A high efficiency of 17.08% is obtained for the mesoscopic perovskite solar cells.
