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Abstract: Co2P nanocrystals were successfully synthesized by a polymer-assisted hydrothermal method. The reaction was carried out at 190 °C–220 °C using cobalt chloride hexahydrate (CoCl2·6H2O) as Co-source and yellow phosphorous as P-source. Polyacrylamide (PAM) was used as surfactant. By controlling the experiment parameters such as the reaction temperature and the amount of polyacrylamide (PAM), Co2P nanocrystals with the rod-like or flower-like morphology could be prepared successfully. The phase and the morphology of the samples were characterized by X-ray diffraction (XRD), transmission electron microscopes (TEM), electron diffraction pattern (ED) and high resolution transmission electron microscope (HRTEM). Furthermore, based on the results of the TEM observation, the possible formation processes of the Co2P nanorods or nanoflowers were also discussed. [Copyright &y& Elsevier]

The first success in the preparation of rare earth hydroxycarbonate thin films has been achieved. Cerium hydroxycarbonate films were prepared by a hydrothermal deposition method, the sample of a single orthorhombic phase was deposited at a lower temperature while those of orthorhombic and hexagonal phases were obtained at higher temperatures. The crystals in the films could be ellipsoidal, prismatic, or rhombic, depending on the deposition conditions applied. The thin films could be candidates for developing novel optical materials and for advanced ceramics processing. [Copyright &y& Elsevier]

Discusses the importance of nanocrystalline nickel in magnetic materials and the development of the ...-radiation method to prepare nanocrystalline materials. How to prepare nanocrystalline nickel powder; Increase of nickel particles and radiation-chemistry yield of nickel in irradiated solutions; Process of reducing Ni2+ ions in solution.

Abstract: Cadmium chalcogenide (CdE, E=S, Se, Te) polycrystalline nanotubes have been synthesized from precursor of CdS/cadmium thiolate complex at room temperature. The precursor was hydrothermally synthesized at 180°C using thioglycolic acid (TGA) and cadmium acetate as starting materials. The transformation from the rod-like precursor of CdS/cadmium thiolate complex to CdS, CdSe and CdTe nanotubes were performed under constant stirring at room temperature in aqueous solution containing S2−, Se2− and Te2−, respectively. The nanotube diameter can be controlled from 150 to 400nm related to the dimension of templates. The XRD patterns show the cadmium chalcogenide nanotubes all corresponding to face-centered cubic structure. [Copyright &y& Elsevier]

Abstract: In this paper, hollow spherical Cu3P nanopowders were synthesized by using copper sulfate pentahydrate (CuSO4⋅5H2O) and yellow phosphorus in a mixed solvent of glycol, ethanol and water at 140–180 ∘C for 12 h. X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), electron diffraction pattern (ED) and transmission electronic microscopy (TEM) studies show that the as-synthesized nanocrystal is pure hexagonal phase Cu3P with a hollow spherical morphology. Based on the TEM observations, a possible aggregation growth mechanism was proposed for the formation of Cu3P hollow structures. Meanwhile, the effects of some key factors such as solvents, reaction temperature and reaction time on the final formation of the Cu3P hollow structure were also discussed. [Copyright &y& Elsevier]

Titanium diboride (TiB2) has been synthesized via a benzene-thermal reaction of metallic sodium with amorphous boron powder and titanium tetrachloride at 400 °C in an autoclave; the temperature was much lower than that of traditional methods. The X-ray diffraction (XRD) pattern can be indexed with the hexagonal cell of TiB2 and the lattice constants a=3.027 and c=3.228 A˚. X-ray photoelectron spectroscopy (XPS) results show the mole ratio of Ti:B as 1:1.766. Transmission electron microscope (TEM) images indicate that the average particle size is in the range of 15–40 nm in diameter. [Copyright &y& Elsevier]

X-ray powder diffraction and high-resolution transmission electron microscopy (HRTEM) have found coexistence of three structures of GaN: wurtzite, zinc blende, and rocksalt in the samples prepared through benzene thermal process at 280–300 °C under pressure about 5 MPa. Previously, GaN with rocksalt structure only appeared at high pressure more than 37 GPa. HRTEM showed that there was a transitional region between the two cubic phases of GaN with zinc blende and rocksalt. X-ray photoelectron spectra analysis of the sample gave the average composition of Ga0.95N. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Vanadium‐based intercalation materials have attracted considerable attention for aqueous zinc‐ion batteries (ZIBs). However, the sluggish interlaminar diffusion of zinc ions due to the strong electrostatic interaction, severely restricts their practical application. Herein, oxygen vacancy‐enriched V2O5 structures (Zn0.125V2O5·0.95H2O nanoflowers, Ov‐ZVO) with expanded interlamellar space and excellent structural stability are prepared for superior ZIBs. In situ electron paramagnetic resonance (EPR) and X‐ray diffraction (XRD) characterization revealed that numerous oxygen vacancies are generated at a relatively low reaction temperature because of partially escaped lattice water. In situ spectroscopy and density functional theory (DFT) calculations unraveled that the existence of oxygen vacancies lowered Zn2+ diffusion barriers in Ov‐ZVO and weakened the interaction between Zn and O atoms, thus contributing to excellent electrochemical performance. The Zn||Ov‐ZVO battery displayed a remarkable capacity of 402 mAh g−1 at 0.1 A g−1 and impressive energy output of 193 Wh kg−1 at 2673 W kg−1. As a proof of concept, the Zn||Ov‐ZVO pouch cell can reach a high capacity of 350 mAh g−1 at 0.5 A g−1, demonstrating its enormous potential for practical application. This study provides fundamental insights into formation of oxygen‐vacant nanostructures and generated oxygen vacancies improving electrochemical performance, directing new pathways toward defect‐functionalized advanced materials. [ABSTRACT FROM AUTHOR]

Stable Zn anodes with a high utilization efficiency pose a challenge due to notorious dendrite growth and severe side reactions. Therefore, electrolyte additives are developed to address these issues. However, the additives are always consumed by the electrochemical reactions over cycling, affecting the cycling stability. Here, hexamethylphosphoric triamide (HMPA) is reported as an electrolyte additive for achieving stable cycling of Zn anodes. HMPA reshapes the solvation structures and promotes anion decomposition, leading to the in situ formation of inorganic‐rich solid‐electrolyte‐interphase. More interestingly, this anion decomposition does not involve HMPA, preserving its long‐term impact on the electrolyte. Thus, the symmetric cells with HMPA in the electrolyte survive ≈500 h at 10 mA cm−2 for 10 mAh cm−2 or ≈200 h at 40 mA cm−2 for 10 mAh cm−2 with a Zn utilization rate of 85.6 %. The full cells of Zn||V2O5 exhibit a record‐high cumulative capacity even under a lean electrolyte condition (E/C ratio=12 μL mAh−1), a limited Zn supply (N/P ratio=1.8) and a high areal capacity (6.6 mAh cm−2). [ABSTRACT FROM AUTHOR]

Stable Zn anodes with a high utilization efficiency pose a challenge due to notorious dendrite growth and severe side reactions. Therefore, electrolyte additives are developed to address these issues. However, the additives are always consumed by the electrochemical reactions over cycling, affecting the cycling stability. Here, hexamethylphosphoric triamide (HMPA) is reported as an electrolyte additive for achieving stable cycling of Zn anodes. HMPA reshapes the solvation structures and promotes anion decomposition, leading to the in situ formation of inorganic‐rich solid‐electrolyte‐interphase. More interestingly, this anion decomposition does not involve HMPA, preserving its long‐term impact on the electrolyte. Thus, the symmetric cells with HMPA in the electrolyte survive ≈500 h at 10 mA cm−2 for 10 mAh cm−2 or ≈200 h at 40 mA cm−2 for 10 mAh cm−2 with a Zn utilization rate of 85.6 %. The full cells of Zn||V2O5 exhibit a record‐high cumulative capacity even under a lean electrolyte condition (E/C ratio=12 μL mAh−1), a limited Zn supply (N/P ratio=1.8) and a high areal capacity (6.6 mAh cm−2). [ABSTRACT FROM AUTHOR]

Red phosphorus shows great promise as a high‐capacity anode material for Na batteries. Such electrodes that suffered from the fracturing impact of volume change during cycling can be effectively improved by 1D nanomaterials. However, the synthesis of 1D red phosphorus has rarely been studied and employed in sodium batteries. Here, a simple selenium‐induced method to generate fibrous nano red phosphorus is presented. It turns out that a small amount of selenium can not only induce high‐quality fibrous nano red phosphorus from commercial red phosphorus, but also benefit qualitatively to the sodium ionic conductivity. Interestingly, the selenium dopant can also manipulate the chemical state of phosphorus leading to valence tunability which is able to tolerate structural stability under the Na‐rich or Na‐poor condition. As a result, the optimal fibrous nano red phosphorus used as anode outperforms over the traditional red phosphorus ≈6 and ≈10 times in terms of rate performance and cycle stability, respectively. Furthermore, as employed for sodium metal anode protection, the symmetrical cell cycling maintains long stable at a low polarization voltage for over 1000 h. The full cell performs excellent cycling stability of 1500 cycles at 3 C and high‐rate performance up to 30 C. [ABSTRACT FROM AUTHOR]

V3O7·H2O (VO) is an attractive cathode material for high‐capacity aqueous Zn‐ion batteries (AZIBs), but it is limited by slow ion mobility and low working platform voltage. Here, a 1,3‐propane diamine (DP)‐intercalated VO with nanoribbon‐assembled thorn flower‐like structure is fabricated by a facile hydrothermal method, noted as VO‐DP. The study shows that the zinc ion diffusion coefficient in VO‐DP (3.1 × 10−8 cm−2 s−1) is five orders of magnitude higher than that of a pure VO counterpart. Auxiliary density functional theory simulation shows that the embedded energy of zinc ions in VO‐DP significantly decreases from 0.24 to −2.5 eV, thus leading to excellent diffusion kinetics and superior rate performance. Benefiting from these unique properties, AZIBs composed of VO‐DP cathodes exhibit high operating voltage (0.89 V), remarkable capacities of 473 mA h g−1 at 0.05 A g−1, excellent rate capability (144 mA h g−1 at 10 A g−1) and long‐term cycling performance (73% capacity retention over 15 000 cycles at 10 A g−1). [ABSTRACT FROM AUTHOR]

Improving the intrinsic catalytic activity of electrocatalysts is considered to be the "gold standard" to inhibit the shuttle effect in Li–S batteries. The question of how to expose active sites for anchoring and catalytic conversion of the polysulfides represents the direction of this research. The assembly of 0D nanoparticles or 2D nanosheets into 3D spherical superstructure is one of the problems of materials synthesis. Here, a spherical superstructure hafnium diboride derived from metal‐organic framework (MOF) nanoparticles is synthesized by one‐step borification. Benefiting from its unique superstructure, the obtained HfB2 exhibits excellent catalytic activity for the conversion of polysulfide. Theoretical calculations indicate that the strong spin–orbital coupling property of electron configuration of 5d Hf induces p orbitals of nonmetallic atoms closer to the Fermi level, thus endowing the anions with redox activity and unconventional superconductivity. These merits enable the HfB2‐based sulfur cathode to deliver a high initial discharge capacity of 1433 mAh g−1 at 0.2 C and 580 mAh g−1 at 5 C. With sulfur loading of 12.8 mg cm−2 and electrolyte dosage of 4 µL mg−1, the areal capacity can reach 15.5 mAh cm−2. This work provides a new understanding for designing superstructure borides involving 5d metals in Li–S batteries. [ABSTRACT FROM AUTHOR]

Highlights: Proposing a one-step pyrolysis strategy to fabricate a novel bilayer-shelled N, O-doped hollow porous carbon microspheres (NOHPC) anode. The optimized NOHPC anode displays a high K-storage capacity of 325.9 mAh g−1 at 0.1 A g−1 and excellent rate performance (201.1 mAh g−1 at 5 A g−1 after 6000 cycles). The assembled NOHPC//hollow porous activated carbon microspheres (HPAC) potassium ion hybrid capacitors deliver a high energy density of 90.1 Wh kg−1 at a power density of 939.6 W kg−1 even over 6000 cycles. With the advantages of high energy/power density, long cycling life and low cost, dual-carbon potassium ion hybrid capacitors (PIHCs) have great potential in the field of energy storage. Here, a novel bilayer-shelled N, O-doped hollow porous carbon microspheres (NOHPC) anode has been prepared by a self-template method, which is consisted of a dense thin shell and a hollow porous spherical core. Excitingly, the NOHPC anode possesses a high K-storage capacity of 325.9 mA h g−1 at 0.1 A g−1 and a capacity of 201.1 mAh g−1 at 5 A g−1 after 6000 cycles. In combination with ex situ characterizations and density functional theory calculations, the high reversible capacity has been demonstrated to be attributed to the co-doping of N/O heteroatoms and porous structure improved K+ adsorption and intercalation capabilities, and the stable long-cycling performance originating from the bilayer-shelled hollow porous carbon sphere structure. Meanwhile, the hollow porous activated carbon microspheres (HPAC) cathode with a high specific surface area (1472.65 m2 g−1) deriving from etching NOHPC with KOH, contributing to a high electrochemical adsorption capacity of 71.2 mAh g−1 at 1 A g−1. Notably, the NOHPC//HPAC PIHC delivers a high energy density of 90.1 Wh kg−1 at a power density of 939.6 W kg−1 after 6000 consecutive charge–discharge cycles. [ABSTRACT FROM AUTHOR]

Anode‐free batteriesgreatly promote overall energy density, but they require an extremely high Coulombic efficiency (CE, >99.7%) to function normally. It becomes very challenging in aqueous batteries, because of water‐related parasitic reactions and dendrite growth on Zn anodes. Herein, aluminum hydroxide fluoride coated on Cu foils (Cu@AOF) is used to realize the anode‐free aqueous batteries. AOF exhibits a high adsorption affinity to H2O and a low diffusion energy barrier for Zn adatoms, promoting the desolvation process and surface migration. Meanwhile, the strong interaction between AOF and Zn2+ enables it to regulate the Zn2+ flux and benefit lateral growth. Then, the anode‐free full cells of Cu@AOF||Zn0.5VO2 exhibit a record‐high cycle life of 2000 cycles at 1 A g−1 with an ultra‐high average CE of 99.95%. More impressively, the full cell shows a long cycle life of 400 cycles with a high CE of 99.94% at −20 °C. This work provides sheds light on the rational engineering of the electrode interfaces to obtain excellent performance at low temperatures. [ABSTRACT FROM AUTHOR]

A method for detecting large-size diamonds with low content in a complex mixture was described. Phase identification via conventional X-ray diffraction method is unsuitable because of the large-size and low-content characteristics of the diamonds. Thus, we proposed a convenient approach (i.e., rocking scan) for assessing the presence of low-content diamonds in a complex mixture. A thorough rocking scan of the (111), (220), and (311) planes revealed the presence of low-content diamonds prepared by reducing dense carbon dioxide with alkali metals. This procedure can be successfully applied to several standard mixture samples prepared by mixing α-SiO 2 , α-Al 2 O 3 , graphite, and pure diamond powders, which are commercially available. We estimated that the detection limit was at or below the 0.1 wt% level by using the proposed method under the current condition. This method is straightforward, routinized, and may be specifically developed to satisfy the requirements of public and private institutions for a rapid identification of other mixture phases, of which the large-size and low-content characteristics do not allow an instant phase identification by conventional X-ray diffraction methods. [ABSTRACT FROM AUTHOR]

Focuses on a simple means of forming diamond. Diamond powder as synthesized through a metallic-reduction-pyrolysis-catalysis route; The temperature as much lower than traditional methods; The x-ray powder diffractions as showing three strong peaks of diamond.

Novel sandwich-like porous carbon nanosheet-supported hexagonal carbon micro-flakes (WPWMC) are fabricated via a one-step hydrothermal route at 700 °C with polyethylene as the precursor and magnesium as the inducer. Through various characterizations, it is confirmed that the hexagonal carbon micro-flakes exhibit (002) orientation, which exposes abundant edge active sites and shortens the K+ transmission path. Moreover, the inside cross-linked carbon nanosheets with abundant pores can accelerate ion diffusion and increase the capacitive contribution. The WPWMC anode displays a high reversible capacity (528.7 mA h g−1 at 0.2 A g−1), good rate capability (152.7 mA h g−1 at 10 A g−1) and long-term cycle stability (112.1 mA h g−1 at 5 A g−1 after 10 000 cycles). Furthermore, the WPWMC//CMK-3 hybrid capacitor exhibits an energy density of 222.7 W h kg−1 at 446.2 W kg−1. This work provides an idea for transforming waste plastic into value-added materials. [ABSTRACT FROM AUTHOR]

Organic electrode materials (OEMs) are emerging green power because of the promising advantages such as environmental friendliness, abundant sources, easy recycling, and structural diversity. However, several inherent issues, including low electronic conductivity, dissolution of active materials, and particle pulverization restrict their practical application. MXene, as a novel 2D material has exhibited enormous potential to solve the issues of OEMs due to its high conductivity, unique structure, exceptional mechanical property, and abundant surface groups. Up to now, various effective strategies have been presented and achieved positive effects, such as constructing heterojunction structures, in situ assembly, dip-coating, preparing freestanding MXene paper, etc. Nonetheless, comprehensive review of the progress and status is rare. Herein, an overview of the application of MXene in organic electrode materials for rechargeable batteries is systematically put forward. Meanwhile, recent progress and future development directions are presented. This review can serve as a guide for future research. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries show promising potential for large‐scale energy storage. However, the large size and heavy mass of Na+ always results in huge volume change and inferior electrochemical stability, especially in alloy‐type anode materials. Here, molecular engineering of the polymer binders, i.e., cross‐linking of poly(acrylic acid) with glycerin (PAA‐GLY), reinforces the mechanical properties, eliminates the active protons of PAA, and benefits electrolyte diffusion, thereby remarkably improving electrochemical performance. Using µ‐Sn as an example, the cycle life at 2 A g−1 is extended from ≈26 cycles of PAA to ≈2000 cycles of PAA‐GLY. Meanwhile, the initial Coulombic efficiency is promoted to 90.3%, allowing the fabrication step of electrode presodiation for full cells to be eliminated. Thus, the full cells run 300 cycles at 2 A g−1. In addition, the binder allows the thick electrode to exhibit an areal capacity of 6.8 mAh cm−2. This binder is also applied for µ‐Bi and µ‐Sb. The simple operation, remarkable improvement, and wide applications indicate the promising prospects of this strategy for advanced electrodes in sodium ion batteries. [ABSTRACT FROM AUTHOR]

Herein, a chemical pre‐potassiation strategy via simultaneously treating both glucose derived carbon (GDC) anode and commercial activated carbon (CAC) cathode in potassium‐naphthalene‐tetrahydrofuran solution is developed for potassium ion hybrid capacitor (PIHC). Combined with in situ and ex situ characterizations, a radical reaction between pre‐potassiation reagent and carbon electrodes is confirmed, which not only deactivates electrochemical irreversible sites, but also promotes to pre‐form a uniform and dense KF‐rich electrolyte film on the electrodes. As a result, the pre‐potassiation treatment presents multiple advantages: (I) the initial Coulombic efficiency (CE) of the GDC anode increases from 45.4 % to 84.0 % with higher rate capability; (II) the CAC cathode exhibits the improved cycling CEs and stability due to the enhanced resistance to electrolyte oxidation at 4.2 V; (III) the assembled PIHC achieves a high energy density of 172.5 Wh kg−1 with cycling life over 10000 cycles. [ABSTRACT FROM AUTHOR]

Herein, a chemical pre‐potassiation strategy via simultaneously treating both glucose derived carbon (GDC) anode and commercial activated carbon (CAC) cathode in potassium‐naphthalene‐tetrahydrofuran solution is developed for potassium ion hybrid capacitor (PIHC). Combined with in situ and ex situ characterizations, a radical reaction between pre‐potassiation reagent and carbon electrodes is confirmed, which not only deactivates electrochemical irreversible sites, but also promotes to pre‐form a uniform and dense KF‐rich electrolyte film on the electrodes. As a result, the pre‐potassiation treatment presents multiple advantages: (I) the initial Coulombic efficiency (CE) of the GDC anode increases from 45.4 % to 84.0 % with higher rate capability; (II) the CAC cathode exhibits the improved cycling CEs and stability due to the enhanced resistance to electrolyte oxidation at 4.2 V; (III) the assembled PIHC achieves a high energy density of 172.5 Wh kg−1 with cycling life over 10000 cycles. [ABSTRACT FROM AUTHOR]

Regulating lithium deposition/stripping behavior in 3D hosts is critical for the development of stable lithium metal batteries. Herein, a low‐tortuosity wood derived carbon (WDC) with gradient‐distributed lithiophilic sites is rationally constructed via biomimetic capillary action, as an efficient scaffold for lithium deposition/stripping. Due to the merits of excellent spatial controllability, the gradient Ag particles modified WDC (WDC‐GDAg) displays favorable bottom‐up Li plating behavior with high columbic efficiency and long cycling stability. Finite element simulation reveals that gradient‐distributed Ag sites enable high lithium flux distribution at the bottom and homogeneous electric field distribution on the top of the WDC electrode. Moreover, the full cells with a WDC‐GDAg anode and a LiFePO4 cathode demonstrate high capacity retention of ≈78.9% after 2000 cycles at 10 C and remarkable rate performance even at 40 C, presenting great potential for practical applications. [ABSTRACT FROM AUTHOR]

Ce-doped α-FeOOH nanorods with high yields were conveniently prepared by a hydrothermal method followed by an acid-treatment process. It is found that Ce uniformly distributes in the α-FeOOH nanorod nanostructures through elemental mapping analysis. The 0.5 wt% Ce-doped α-FeOOH electrode displayed excellent cycling performance with a high discharge capacity of 830 mA h g −1 after 800 charge/discharge cycles at a high current of 2000 mA g −1 . The enhanced electrochemical performance can be attributed to the improved electronic conductivity, Li-ion diffusion kinetics and structure stability after Ce doping. Furthermore, a 0.5 wt% Ce-doped α-FeOOH//LiFePO 4 lithium ion cell with an initial discharge capacity of 580 mA h g −1 at 1000 mA g −1 based on the total weight of the anode material has been fabricated for the first time. The obtained 0.5 wt% Ce-doped α-FeOOH electrode as anode material for sodium-ion batteries also exhibits a high initial discharge capacity of 587 mA h g −1 at 100 mA g −1 . [ABSTRACT FROM AUTHOR]

Zn metal as one of promising anode materials for aqueous batteries suffers from notorious dendrite growth, serious Zn corrosion and hydrogen evolution. Here, a bifunctional electrolyte additive, N‐methyl pyrrolidone (NMP), is developed to improve the electrochemical performance of Zn anode. NMP not only alters the solvation structure of Zn2+, but also in situ produces a dense N‐rich solid‐electrolyte‐interphase layer on Zn foils. This layer protects Zn foils from corrosive electrolytes and benefits the uniform plating/stripping of Zn. Hence, the asymmetrical cells with NMP in the electrolyte retain a high coulombic efficiency of 99.8 % over 1000 cycles. The symmetric cells survive ≈200 h for 10 mAh cm−2 at a high Zn utilization of 85.6 %. The full cells of Zn||MnO2 show an impressive cumulative capacity even with lean electrolyte (E/C ratio=10 μL mAh−1), limited Zn supply (N/P ratio=2.3) and high areal capacity (5.0 mAh cm−2). [ABSTRACT FROM AUTHOR]

Zn metal as one of promising anode materials for aqueous batteries suffers from notorious dendrite growth, serious Zn corrosion and hydrogen evolution. Here, a bifunctional electrolyte additive, N‐methyl pyrrolidone (NMP), is developed to improve the electrochemical performance of Zn anode. NMP not only alters the solvation structure of Zn2+, but also in situ produces a dense N‐rich solid‐electrolyte‐interphase layer on Zn foils. This layer protects Zn foils from corrosive electrolytes and benefits the uniform plating/stripping of Zn. Hence, the asymmetrical cells with NMP in the electrolyte retain a high coulombic efficiency of 99.8 % over 1000 cycles. The symmetric cells survive ≈200 h for 10 mAh cm−2 at a high Zn utilization of 85.6 %. The full cells of Zn||MnO2 show an impressive cumulative capacity even with lean electrolyte (E/C ratio=10 μL mAh−1), limited Zn supply (N/P ratio=2.3) and high areal capacity (5.0 mAh cm−2). [ABSTRACT FROM AUTHOR]

Dual‐ion batteries have shown promising prospect in energy storage, owing to their low material costs, high power capability, and environmental friendliness. However, graphite as the cathode always suffers from structural damage and electrode/electrolyte interface instability, which greatly deteriorate their electrochemical performance. Here, tris(trimethyl‐silyl) phosphite (TMSP) is added as an electrolyte additive to improve the electrochemical performance. TMSP not only scavenges the deleterious species generated by electrolytes, but also produces a thin and uniform cathode–electrolyte interphase layer on graphite. Hence, the electrochemical performance is greatly promoted. In graphite||graphite, the capacity retention is ≈96.8% at 30 °C or 92.5% after 3000 cycles in the presence of TMSP, much better than those without TMSP (62% at 30 °C or 27% after 200 cycles). [ABSTRACT FROM AUTHOR]

Uncontrollable lithium dendrite growth which typically results in poor cycling stability and safety issues remains a great challenge for lithium metal batteries. Herein, we report a novel separator modification strategy by using polydimethylsiloxane (PDMS) to functionalize a glass fiber separator to inhibit dendrite growth. The PDMS-modified separator not only acts as a mechanical barrier but also promotes the desolvation of lithium ions. Consequently, Li/Li symmetric cells with optimal PDMS-modified separators are able to stably cycle for more than 1200 hours at 2 mA cm−2 with a stable polarization voltage (about 60 mV). Moreover, with the assistance of the functionalized separator, the assembled Li/LiFePO4 full cell can impressively achieve capacity retention up to 82.5% and a coulombic efficiency of ∼99.4% after 200 cycles at 1.0 C. The PDMS functionalization strategy provides a simple and efficient approach for developing safe and high-performance lithium metal batteries. [ABSTRACT FROM AUTHOR]

Designing water‐deficient solvation sheath of Zn2+ by ligand substitution is a widely used strategy to protect Zn metal anode, yet the intrinsic tradeoff between Zn nucleation/dissolution kinetics and the side hydrogen evolution reaction (HER) remains a huge challenge. Herein, we find boric acid (BA) with moderate ligand field interaction can partially replace H2O molecules in the solvation sheath of Zn2+, forming a stable water‐deficient solvation sheath. It enables fast Zn nucleation/dissolution kinetics and substantially suppressed HER. Crucially, by systematically comparing the ligand field strength and solvation energies between BA and the ever‐reported electrolyte additives, we also find that the solvation energy has a strong correlation with Zn nucleation/dissolution kinetics and HER inhibition ability, displaying a classic volcano behavior. The modulation map could provide valuable insights for solvation sheath design of zinc batteries and beyond. [ABSTRACT FROM AUTHOR]

Designing water‐deficient solvation sheath of Zn2+ by ligand substitution is a widely used strategy to protect Zn metal anode, yet the intrinsic tradeoff between Zn nucleation/dissolution kinetics and the side hydrogen evolution reaction (HER) remains a huge challenge. Herein, we find boric acid (BA) with moderate ligand field interaction can partially replace H2O molecules in the solvation sheath of Zn2+, forming a stable water‐deficient solvation sheath. It enables fast Zn nucleation/dissolution kinetics and substantially suppressed HER. Crucially, by systematically comparing the ligand field strength and solvation energies between BA and the ever‐reported electrolyte additives, we also find that the solvation energy has a strong correlation with Zn nucleation/dissolution kinetics and HER inhibition ability, displaying a classic volcano behavior. The modulation map could provide valuable insights for solvation sheath design of zinc batteries and beyond. [ABSTRACT FROM AUTHOR]

Although it is well acknowledged that regulating the adsorption behavior of oxygen-containing intermediates can prompt the reaction kinetics of lithium–oxygen batteries, its implementation still suffers from lacking a practical strategy. The amorphization strategy has great potential for custom-tuning surface engineering due to the induced atomic disorder possessing unique electronic structures and abundant defect sites. In this work, amorphous NiCo2O4 nanosheets (a-NiCo2O4 NSs) are reported for high-performance lithium–oxygen batteries by modulating the electron density around metal sites. The Li–O2 batteries with a-NiCo2O4 NSs deliver an overpotential as low as 0.74 V with an ultralong lifetime of over 1000 h. Theoretical calculations reveal that the enhanced binding energy of the LiO2 intermediate is stemmed from d-band center upshifting, mediated by atomic disordering, which consequently yields low oxygen evolution-reaction and oxygen-reduction-reaction overpotentials. More importantly, the amorphization strategy can be utilized as a general approach toward other materials, such as cobalt oxide and nickel oxide. [ABSTRACT FROM AUTHOR]

NiO polyhedron nanocrystals have been synthesized using a single source of nickel chloride through a calcination reaction. The electrochemical results displayed that the obtained sample is an outstanding anode material for lithium ion batteries (LIBs). The sample maintains a high specific capacity of 645.5 mAh g −1 at current density of 1000 mA g −1 after 100 cycles. Even at high current density of 4000 mA g −1 , the NiO polyhedron nanocrystals still deliver a capacity of 459.6 mAh g −1 . The high specific capacity, long stable cyclic property and good rate capability make the NiO polyhedron nanocrystals a good candidate anode material for high-performance LIBs. [ABSTRACT FROM AUTHOR]

Hollow structures of transition-metal oxides, particularly mixed-metal oxides, could be promising for various applications such as lithium-ion batteries (LIBs). Compared to the synthesis of metal oxide hollow spheres by the template method, non-spherical metal oxide hollow hexagonal polyhedra have not been developed to date. Herein, we report the controlled hydrothermal synthesis of a new phase of Co3V2O8⋅ n H2O hollow hexagonal prismatic pencils (HHPPs), which is composed of uniform structural units. By varying the amount of NaOH in the presence of NH4+ and without any template or organic surfactant, the hexagonal prismatic pencils gradually transform from solid into hollow structures, with sizes varying from 5 to 20 μm. The structure of pencils can be preserved only in a limited range of the molar ratio of OH−/NH4+. As a new anode material for LIBs, such hollow pencils exhibit impressive lithium storage properties with high capacity, good cycling stability, and superior rate capability. [ABSTRACT FROM AUTHOR]

Hollow structures of transition-metal oxides, particularly mixed-metal oxides, could be promising for various applications such as lithium-ion batteries (LIBs). Compared to the synthesis of metal oxide hollow spheres by the template method, non-spherical metal oxide hollow hexagonal polyhedra have not been developed to date. Herein, we report the controlled hydrothermal synthesis of a new phase of Co3V2O8⋅ n H2O hollow hexagonal prismatic pencils (HHPPs), which is composed of uniform structural units. By varying the amount of NaOH in the presence of NH4+ and without any template or organic surfactant, the hexagonal prismatic pencils gradually transform from solid into hollow structures, with sizes varying from 5 to 20 μm. The structure of pencils can be preserved only in a limited range of the molar ratio of OH−/NH4+. As a new anode material for LIBs, such hollow pencils exhibit impressive lithium storage properties with high capacity, good cycling stability, and superior rate capability. [ABSTRACT FROM AUTHOR]

[Display omitted] As an indispensable part of electric devices, separator play a key role in electrochemical performance. Thus, separator engineering is a promising way of constructing better energy storage and conversion systems. MXenes, a novel class of 2D transition metal nitrides, carbides, and carbonitrides, are emerging for separator engineering due to their unique properties, such as high conductivity, large surface area, controllable hydrophilicity, abundant surface chemistries, and superior mechanical performance. The related investigations have remarkably increased since 2020. However, comprehensive reviews on this topic are rare. Herein, an overview of MXenes in separator engineering for rechargeable batteries is systematically presented. Firstly, the fundamental principles of MXenes, including composition, synthesis techniques, and functionalization, are summarized. Subsequently, the basic information on separator design and its optimization is introduced. Finally, the applications of MXenes for separator engineering and their applications in rechargeable batteries are reviewed. In the end, the perspectives and challenges on the further development of MXenes-based separators in rechargeable batteries are proposed. This review will help researchers in the design and construction of functional separators for batteries, supercapacitors, fuel cells, etc. [ABSTRACT FROM AUTHOR]

Abstract: Graphene-like structure of V2O3 had been synthesized by a top-down precursor-pyrolyzation strategy. The first-order transformation of V2O3 disappeared with the increasing of temperature. It represents a positive temperature coefficient semiconductor behavior. It is a noteworthy and promising candidate for ultrathin energy-storage devices. The discharge capacity of V2O3 nanosheets is maintained at 300mAh/g after 75 cycles at the current density of 200mA/g, which exhibits excellent discharge capacity and superior cycling stability. Flower-like precursors composed of nanosheets were also successfully synthesized by adjusting temperature and time. V2O3 has perfectly inherited the morphology of its precursors. The new method demonstrated here provides a new way in the preparation of other ultrathin nanosheets materials. [Copyright &y& Elsevier]

Anode materials with a high initial coulombic efficiency and a long lifespan are highly desirable for sodium-ion batteries. Here, bimetallic μ-BiSn microspheres well combine the high capacity of Sn and the good stability of Bi together, exhibiting superior electrochemical performance, such as a high initial Coulombic efficiency (90.6%), a good cycling stability (541 mA h g−1 after 3000 cycles at 2 A g−1) and an excellent rate capability (393 mA h g−1 at 10 A g−1). [ABSTRACT FROM AUTHOR]

Although lithium–sulfur batteries have high theoretical energy density of 2600 Wh kg−1, the sluggish redox kinetics of soluble liquid polysulfide intermediates during discharge and charge is one of the main reasons for their limited battery performance. Designing highly efficient electrocatalysts with a core–shell like structure for accelerating polysulfide conversion is vital for the development of Li–S batteries. Herein, core–shell MoSe2@C nanorods are proposed to manipulate electrocatalytic polysulfide redox kinetics, thereby improving the Li–S battery performance. The 1D MoSe2@C is synthesized via a facile hydrothermal and subsequent selenization reaction. The electrocatalysis of MoSe2 is confirmed by the analysis of symmetric batteries, Tafel curves, changes of activation energy, and lithium‐ion diffusion. Density functional theory calculations also prove the low Gibbs free energy of the reaction pathway and the lithium‐ion diffusion barrier. Therefore, the Li–S batteries using MoSe2 electrocatalyst exhibit an excellent rate performance of 560 mAh g−1 at 1 C with a high sulfur loading of 3.4 mg cm−2 and an areal capacity of 4.7 mAh cm−2 at a high sulfur loading of 4.7 mg cm−2 under lean electrolyte conditions. This work provides a deeper insight into regulation of polysulfide redox kinetics in electrocatalysts for Li–S batteries. [ABSTRACT FROM AUTHOR]

Red phosphorus (RP), with high theoretical specific capacity and low working potential, has been regarded as one of the most promising anodes for high‐performance sodium‐ion batteries (SIBs). However, the unsatisfactory performance of RP anodes especially under high mass loading conditions severely limited the development for practical applications, due to its large volume variations during cycling processes, and the poor electronic and ionic conductivity. Here, a hierarchical WDC/CNTs@RP electrode with high mass loadings of RP (up to 14.1 mg cm−2) and superior conductivity is rationally designed for both ions and electrons. Such unique hierarchical structures enable an unprecedented rate performance (1.63 mAh cm−2 under 106.6 mA cm−2), long cycling life, and a decent gravimetric capacity of 468.88 mA h g−1 based on the whole electrode and inactive components. This work presents an essential step toward practical applications of RP anode materials for SIBs batteries. [ABSTRACT FROM AUTHOR]

The aqueous rechargeable sodium‐ion battery (ARSIB) is considered to be the most promising candidate for large‐scale energy storage applications, due to its low cost, safety, and eco‐friendliness. However, the poor cycle life and low energy density of ARSIB impede its practical applications. In this context, hollow NaTi2(PO4)3 nanocubes anode is engineered through a facile, low‐cost, and large‐scale hydrothermal approach. Na0.44MnO2 cathode delivers a high capacity of 75.16 mAh g−1 with the compensation of sodium ions by the zinc metal‐induced pre‐sodiation of the anode in a deep eutectic electrolyte. The well‐designed structure in hollow carbon‐coated NaTi2(PO4)3 nanocubes enables high stability and rate performance. Moreover, the adoption of deep eutectic electrolytes can minimize the Mn dissolution in the Na0.44MnO2 cathode. When coupling the cathode and anode, the as‐assembled ARSIB with a deep eutectic electrolyte exhibits an ultralong cycle life up to 3500 cycles (with capacity retention of 90%), an ultrahigh energy density of 50.0 Wh kg−1, and superior rate capability (maximum power density of 1500 W kg−1). This ARSIB represents an alternative promising candidate for large‐scale electrochemical energy storage. [ABSTRACT FROM AUTHOR]

[Display omitted] Chemical prelithiation is regarded as a crucial method for improving the initial Coulombic efficiency (ICE) of Li-storage anodes. Herein, a substituent-engineered Li-cyanonaphthalene chemical prelithiation system is designed to simultaneously enhance the ICE and construct a multifunctional interfacial film for SiO electrodes. X-ray photoelectron spectroscopy (XPS), electron energy-loss spectroscopy (EELS), nuclear magnetic resonance (NMR) spectroscopy and atomic force microscopy (AFM) prove that the Li-cyanonaphthalene prelithiation reagent facilitates the formation of a rectified solid electrolyte interface (SEI) film in two ways: (1) generation of a gradient SEI film with an organic outer layer (dense N-containing organics, ROCO 2 Li) and an inorganic LiF-enriched inner layer; (2) homogenization of the horizontal distribution of the composition, mechanical properties and surface potential. As a result, the prelithiated SiO electrode exhibits an ICE above 100%, enhanced CEs during cycling, better cycle stability and inhibition of lithium dendrite formation in the overcharged state. Notably, the prelithiated hard carbon/SiO (9:1)‖LiCoO 2 cell displays an enhancement in the energy density of 62.3%. [ABSTRACT FROM AUTHOR]

Highlights: [•] The nanosized CdO and CdO/CNTs nanocomposites were prepared by a facile solution route. [•] The CdO could be used as a novel high capacity anode with both alloying and conversion reactions. [•] Both the CNTs incorporation and binder choice can improve the cycle ability of CdO by buffering the volume changes and maintaining the integrity of the electrodes. The binder effect is more crucial. [•] The CdO/CNTs nanocomposites with water-soluble binder could deliver a capacity of 810 mAh g−1 even after 100 cycles at 0.1 A g−1 and a capacity of 720 mAh g−1 even at the rate of 1500mAg−1. [Copyright &y& Elsevier]

Abstract: Well dispersed chestnut-like Cd2Ge2O6 (CGO) and Cd2Ge2O6/reduced graphene oxide (CGO/RGO) nanocomposites are successfully prepared via a facile one-pot hydrothermal method and characterized as novel lithium storage materials for the first time. Electrochemical characterization of lithiation/delithiation of the CGO/RGO nanocomposites reveals a large capacity of 943mAhg−1 for the first cycle and a capacity retention of 721mAhg−1 even after 100 cycles. The superior electrochemical performance of the CGO/RGO nanocomposites electrode compared to the pure CGO electrode can be attributed to the well dispersed RGO which enhances the electronic conductivity and accommodate the volume change during the lithium storage process. [Copyright &y& Elsevier]

A new type of anode material in which small‐sized CoP nanoparticles coated with N‐doped carbon are immobilized into 1D nitrogen‐doped carbon frameworks (CoP@NC⊂NCFs) is accurately synthesized via self‐template catalysis. The hierarchical structure bears various structural advantages, including more active sites and ultrahigh electrical conductivity provided by enriched nitrogen, strong interface interaction between CoP and N‐doped carbon, and the stability of the structure. As a result, the rapid potassium ion reaction kinetics and the strong adsorption of potassium ions of CoP are realized, verified by galvanostatic intermittent titration and density function theory calculations. In addition, through the advanced in situ characterization techniques, the solid‐solution reaction mechanism of CoP and potassium ions is clarified. The zero‐strain structure of CoP further ensures structural robustness, giving CoP@NC⊂NCFs excellent potassium storage properties, especially cycle stability with a capacity of ≈206 mAh g−1 at 0.1 A g−1 for 1200 cycles, achieving an ultralow decay rate of 0.01%. The corresponding K‐ion full cell is also prepared, as expected, and shows stable capacity retention. [ABSTRACT FROM AUTHOR]

Promoting the solution phase formation of Li2O2 rather than on the cathode surface is a key issue for high‐performance Li–O2 batteries. Protic additives have been reported to guide the discharge of Li2O2 in the electrolyte solution, while further advances are stalled by the intrinsical reactivity to Li metal to deteriorate the lifespan of Li–O2 batteries. Herein, rhodamine B (RhB), a protic additive, is first introduced into electrolyte as a phase‐transfer catalyst to achieve solution phase formation of Li2O2. The yield of Li2O2 is 90.79%, and the discharge capacity is 46 000 mAh gcarbon−1 at current density of 1000 mA gcarbon−1, which is 23‐fold higher than that of blank electrolyte. Density functional theory calculations further demonstrate the feasibility of RhB to boost solution phase discharge. Most notably, the free chlorine ion in RhB assists the in situ formation of a stable Li+‐conducting solid electrolyte interphase to protect Li anode from corrosion and dendrite formation during cycling. As a result, Li||Li symmetric cells exhibit a long cycle performance up to 1300 h at 1 mA cm−2 with low hysteresis voltage. Benefiting from the above results, Li–O2 batteries with RhB present long cycle stability. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous batteries are emerging power sources due to the merits of high safety, low cost, environmental friendliness, etc. However, several key issues such as narrow electrochemical stability window, dissolution of active materials, notorious dendrite growth and poor cycling lifespan hinder the practical application of aqueous batteries. Recently, 2D MXenes and their derivatives for aqueous batteries have exhibited substantial encouraging progress due to the special characters. The related researches have dramatically increased since 2019. However, comprehensive reviews on this topic are rare. Herein, the latest advances of MXenes and their derivatives for aqueous Zn-, Li-, Na- and dual-ion batteries are systematically reviewed, including cathode fabrication, anode design and electrolyte optimization, etc. This review aims to boost rational design strategies for practical application of aqueous batteries by combining the fundamental principle and research developments. Firstly, the fundamental background of aqueous rechargeable batteries is introduced and the superior merits for electrochemical energy storage of MXenes and their derivatives are summarized. Subsequently, the design strategies and internal mechanism of MXenes and their derivatives for aqueous batteries are comprehensively summarized and discussed. Finally, perspectives on the future design tactics of MXenes-based materials for aqueous batteries are proposed. [ABSTRACT FROM AUTHOR]

The construction of hierarchical nanostructures is a fascinating target because of their promising applications in electronic analysis and catalysis. Herein, we establish a 3‐d hierarchical nanostructure Co−P@CoMo−P to enhance the catalytic ability. The hydrogen evolution reaction catalytic ability was enhanced significantly with a Tafel slope of 34 mV dec−1 and an overpotential of 37 mV to achieve 10 mA cm−2, which are superior to that of recently reported non‐noble metal catalysts. The high catalytic performance could be rationalized as follows: (1) Co−P nanowire intimately contacted with Ni foam enables good mechanical adhesion and facilitates the flow of electrons from Ni foam to CoMo−P nanosheet; (2) the hierarchical nanostructure can expose more active sites and transport reactants and products sufficiently; (3) the space between two separate hierarchical nanostructures is loose and open, allowing electrolyte to diffuse into all the active sites and make them used efficiently. This work is promising for the development of novel non‐noble metal catalysts for energy technologies. [ABSTRACT FROM AUTHOR]

Abstract: Large-scale Mn2O3 homogeneous core/hollow-shell structures with cube-shaped and dumbbell-shaped morphologies have been synthesized trough a facile and low-cost method. The microscopy analyses indicate that the core-shell microcubes have an average edge length of 2.5μm with a shell thickness of about 150nm, and the core-shell microdumbbells were formed with a length of about 3μm and shell thickness of about 160nm. The possible formation mechanism was discussed on the basis of transmission electron microscopy observations. The novel homogeneous core/hollow-shell structures were found to exhibit excellent performance in wastewater treatment. [Copyright &y& Elsevier]

Single-crystal six-horned nanospheres of Cu2O with a diameter of 760 nm in average were prepared in aqueous solution of CuCl2and NaOH by using ascorbic acid as the reductant in the presence of sodium dodecyl benzenesulfonate (SDBS) at room temperature. The horn grows along the <100> direction, which is consistent with the protuberant direction of an apex of octahedron. The formation process of six-horned nanospheres included two steps: the formation of Cu2O nanospheres via Ostwald ripening process, and the appearance of horns on the surface of nanospheres under low concentration of SDBS. As increasing the concentration of SDBS, the six-horned nanospheres could be transformed into octahedron-like Cu2O. And at the same concentration of SDBS, keeping the volume ratio of water and ethanol in mixed solutions as 1:1, Cu2O octahedra were obtained. Moreover, gas-sensing property showed that six-horned nanospheres of Cu2O had higher sensitivity compared with Cu2O nanospheres and Cu2O octahedra to ethanol gas (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Abstract: A shape-controlled synthesis of carbon-encapsulated Fe3O4 core/shell (Fe3O4@C) composites is reported in this paper. By tuning the reaction temperature from 500°C to 700°C and the amount of ammonium acid carbonate (1.0g, 0.5g and 2.0g) in a sealed reaction system, Fe3O4@C composites with hexapod-like, flake-like, and chain-like morphologies have been successfully obtained using ferrocene as the precursor. Corresponding hollow carbon structures can be obtained by acid treatments. The three kinds of Fe3O4@C composites show ferromagnetic properties at room temperature, while their saturation magnetizations and coercivities are obviously different from each other, due to the various shapes and structures. Possible formation processes of these Fe3O4@C composites and corresponding hollow carbon materials are discussed. The experimental results indicate that the reaction temperature and the amount of ammonium acid carbonate play key roles in the shape-controlled synthesis of hexapod-like, flake-like and chain-like Fe3O4@C composites. [Copyright &y& Elsevier]