Active Ions Research Articles

Enabling Ultrafast Single Mg2+ Insertion Kinetics of Magnesium-Ion Batteries via In Situ Dynamic Catalysis and Re-equilibration Effects.

Magnesium-ion batteries (MIBs) have great potential in large-scale energy storage field with high capacity, excellent safety, and low cost. However, the strong solvation effect of Mg2+ will lead to the formation of solvated ions in electrolytes with larger size and sluggish diffusion/reaction kinetics. Here, the concept of interfacial catalytic bond breaking is first introduced into the cathode design of MIBs by hybriding MoS2 quantum dots with VS4 (VS4@MQDs) as the cathode. The "in situ dynamic catalysis and re-equilibration" effects can catalyze the Cl-Mg bond breaking and trigger single Mg2+ insertion/extraction chemistries, which can significantly accelerate the diffusion and reaction kinetics, as verified by the decreased diffusion energy barriers (0.26 eV for Mg2+ vs 2.47 eV for MgCl+) and fast diffusion coefficient. Benefitting from these dynamic catalysis effects, the constructed VS4@MQD-based MIBs deliver a high discharge capacity of ∼120 mA h g-1 at 200 mA g-1 and a long-term cyclic stability of 1000 cycles at 1 A g-1. The improved performance and detailed characterizations well prove that the active ions in MIBs change from MgCl+/Mg2Cl3+ to Mg2+ with fast kinetics.

Comparison of the consequences of state of charge and state of health on the thermal runaway behavior of lithium ion batteries

In this work the influence of the SoC and the SoH on the thermal runaway was analyzed in depth (SoC 30–100 % /SoH 75–100 %). Generally, the results show a decrease in the strength of the TR reactions with decreasing SoC/SoH. The determined surface temperatures decrease by >100 °C when SoC and SOH are reduced to 50 % SoC or 75 % SoH because there are fewer stored and active lithium ions as well as less overall stored energy and more inactive components. Released particles and gas caused a mass loss reduction of 12.5 % (SoC) and 7 % (SoH), respectively, with measurable gas concentrations of decomposition products and linear hydrocarbons decreasing. At the same time the concentrations of gaseous electrolyte components increase. A comparative analysis at SoC 80 % or SoH 80 % shows that the amount of stored energy or Li-ions incorporated at the time of penetration into the anode is responsible for the main reaction characteristics, which include the course of the voltage drop, the temperature evolution and the composition of the reaction gases. However, despite aging effects occurring with SoH reduction, the surface temperatures and determined gas concentrations reach the same values. At microscopic scale, changes in the reactions, e.g. SEI-decomposition, are expected, but no effect on the macroscopic TR is measurable. In general, it has been shown that both lower SoC and SoH minimize the severity of an occurring TR. In summary, it could be determined that cell surface temperatures drop by the same average values, up to 100 °C, for the same reduction in SoC and SoH. Gas concentrations decrease, as do cell mass loss parameters. With lower energy, the amount of carbonate compounds in the gas phase increases, with decomposition products increasing with increased energy. In general, it has been shown that both lower SoC and SoH minimize the severity of an occurring TR. In a comparative analysis of decreased SoC and SoH, it was shown that the type of decrease in stored Li-ion amounts, setting SoC 80 % or SoH 80 %, does almost not affect the macroscopically detectable responses of TR. The surface temperatures reached on the cell, as well as the gas concentrations determined and parameters such as the penetration depth to the TR and the mass loss show identical values for SoC 80 % and SoH 80 %. In the final analysis, it is the quantity of stored Li-ions that determines the effects and strength of the TR, and effects such as cyclic aging or state of charge are negligible on a macroscopic level. The results help to better allocate the effects of aging and charging to the utilization phase and existing hazards, and form the basis for further predictions and simulations.

On the Quenching Mechanism of Ce, Tb Luminescence and Scintillation in Compositionally Disordered (Gd, Y, Yb)3Al2Ga3O12 Garnet Ceramics

Two series of (Gd, Y, Yb)3Al2Ga3O12 quintuple compounds with a garnet structure and solely doped with Ce and Tb were prepared in the form of ceramics by sintering in oxygen at 1600 °C for two hours and studied for the interaction of activator ions with ytterbium ions entering the matrix. It was shown that the photoluminescence and scintillation of Ce3+ ions are completely suppressed, predominantly by tunneling ionization through the charge transfer state (CTS) of the Ce4+-Yb2+ ions. The photoluminescence of Tb3+ ions is quenched in the presence of ytterbium, but not completely due to the poor resonance conditions of Tb3+ intraconfiguration transitions and the CTS of the single Yb3+ and the CTS of Ce4+-Yb2+ ions. The scintillation in the visible range of both Ce3+- and Tb3+-doped samples is intensely quenched as well, which indicates strong competition from Yb3+ ions to activators in interaction with the Gd substrate.

Adjustment of Bi3+ Luminescence and Thermal Quenching Properties by B'-Site Ion Substitution Strategy in Double Perovskite CaLaMgSb/TaO6:Bi3+ Phosphor.

Thermal quenching has always been one of the most difficult issues in creating high-quality phosphor conversion light-emitting diodes (pc-LED), and a family of strategies are urgently needed to improve the luminescence performance of phosphors at high temperatures. In this contribution, a novel B'-site substitution CaLaMgSbxTa1-xO6:Bi3+ phosphor was constructed using an ion substitution strategy in the matrix with a green activator Bi3+ and a novel double perovskite material. When Sb5+ replaces Ta5+, a surprising increase in luminescence intensity occurs and the thermal quenching properties are greatly improved. The shift of the Raman characteristic peak to a smaller wavenumber and the reduction of the Bi-O bond length confirm that the crystal field environment around Bi3+ changes, which has a substantial effect on the crystal field splitting and nepheline effect of Bi3+ ions, affecting the crystal field splitting energy (Dq). This results in a corresponding increase of the band gap and the thermal quenching activation energy (ΔE) of the activator Bi3+. From the perspective of Dq, the intrinsic relationships among the activator ion band gap, bond length, and Raman characteristic peak changes were analyzed, and a mechanism for regulating luminescence thermal quenching properties was constructed, which provides an effective strategy for improving the promising new materials such as double perovskite.

Imbalance of active ions through segmented electrodes: Mass transfer characteristics of vanadium redox flow batteries

The mass transfer that occurs at the interface between the porous electrode and electrolyte is important because it is closely related to the electrochemical performance of batteries. In general, as the materials used for electrodes have irregularly connected microscale pores, various methods exist to predict the permeation path of the electrolyte between the inlet and outlet. In this study, we investigate the use of segmented cells to experimentally visualize the mass transfer properties that occur during electrochemical reactions in porous electrodes. In this work, the measured voltages are quantitatively compared with the voltage deviation for each electrode position for a segment cell that is divided into 25 active areas, each measuring 25 cm2. As a result, the electrochemical reaction for each charge/discharge process caused by the physical and electrochemical properties of the VRFB electrolyte showed a relatively uniform reactivity during the charging process. The strategy of enhancing the supply of active ions by increasing the flow rate does not contribute to reducing the voltage difference inside the active region. When the current density is increased by 100%, the rate of increase of the voltage deviation by the electrode position is 70% and 140% in the charging and discharging process, respectively. Furthermore, in the DoD 100% discharge stage based on the cell voltage, the voltage difference is approximately 6.3 times higher than the average voltage deviation in the SoC 0–100% and DoD 0–90% stages. This paper presents a strategy to ensure stable operation during the system charge/discharge process by measuring the voltage at each position of the porous electrode used as an electrode.

First-principles calculations of electronic and optical properties of Ce3+-activated phosphors toward evaluating valence stability of Eu ions

The valence stability of activator ions with multiple stable valence states has always been a major concern in the field of luminescent materials. Here we present a computational protocol that is able to predict the valence stability of the europium (Eu) ion in its activated phosphors, in terms of the energy difference between the ground-state level of Eu2+ and the Fermi level of the host. The protocol is based on hybrid density functional theory (DFT) and wavefunction-based multiconfigurational ab initio calculations of the dopant Ce3+, in conjunction with the established relationship between energy levels of Ce3+ and Eu2+. The predictions are in good agreements with experimental findings. It is demonstrated that across the study set consisting of five borate-containing phosphors, the valence stability of the dopant Eu2+ is positively correlated with the host band gap, and this positive correlation is more significant than the negative correlation with the energy level of Eu2+ within the host band gap. Microscopic analysis reveals that a strong bonding of electrons within the anion groups together with a large dopant site is beneficial for the reduction of Eu3+ into Eu2+. The influence of hybrid DFT functional on the predicted valence stability of a given compound was found be negligible due to cancellation of changes in the host band gap and the Eu2+ ground level. This study clarifies the reasons for the stabilization of Eu2+ in phosphors synthesized in air at high temperature and is expected to help to screen out the host compounds that could stabilize Eu2+ activators for diverse optical applications.

Optimized osteogenesis of biological hydroxyapatite-based bone grafting materials by ion doping and osteoimmunomodulation.

Biological hydroxyapatite (BHA)-based bone grafting materials have been widely used for bone regeneration in implant surgery. Much effort has been made in the improvement of their osteogenic property as it remains unsatisfactory for clinical use. Osteoimmunomodulation plays a significant role in bone regeneration, which is highly related to active inorganic ions. Therefore, attempts have been made to obtain osteoimmunomodulatory BHA-based bone grafting materials with optimized osteogenic property by ion doping. To summarize and discuss the active inorganic ions doped into BHA and their effects on BHA-based bone grafting materials. A literature search was performed in databases including Google Scholar, Web of Science and PubMed, with the elementary keywords of "ion doped" and "biological hydroxyapatite", as well as several supplementary keywords. All document types were included in this search. The searching period and language were not limited and kept updated to 2022. A total of 32 articles were finally included, of which 32 discussed the physiochemical properties of BHA-based biomaterials, while 12 investigated their biological features in vitro, and only three examined their biological performance in vivo. Various ions were doped into BHA, including fluoride, zinc, magnesium and lithium. Such ions improved the biological performance of BHA-based biomaterials, which was attributed to their osteoimmunomodulatory effect. The doping of active inorganic ions is a reliable strategy to endow BHA-based biomaterials with osteoimmunomodulatory property and promote bone regeneration. Further studies are still in need to explore more ions and their effects in the crosstalk between the skeletal and immune systems.

Preparation, microstructures and luminescence properties of transparent red-emitting Eu2Ca0.6(MoO4)3.6 suspension

Eu2Ca1−x(MoO4)4−x (x = 0, 0.20, 0.40, 0.60, 0.80, 1), non-concentration quenching phosphors with 100% of Eu3+ activator ion, were synthesized. Nano-sized phosphors were synthesized via a solvothermal reaction by using non-polar Ca-oleate, Eu-oleate and TOA–MoO4 complexes as surfactant complexes prepared through a phase-transfer method in a water-toluene bilayer system. Among the Eu2Ca1−x(MoO4)4−x, Eu2Ca0.6(MoO4)3.6 showed the strongest red emission at 615 nm due to the 5D0 → 7F2 transition of the Eu3+ ions. The mean size of the Eu2Ca0.6(MoO4)3.6 is ∼5 nm, which is sufficiently small to avoid light-scattering behavior. Thus, the Eu2Ca0.6(MoO4)3.6 nanophosphor can be used as a red-emitting material in transparent displays.

Chemically and electronically active metal ions on InAs quantum dots for infrared detectors

Colloidal InAs quantum dots (QDs) are emerging candidates for NIR-SWIR optoelectronic applications because of their excellent electrical and optical properties. However, the syntheses of InAs QDs, which demand strongly reducing atmospheres or highly reactive precursors, are difficult because of their highly covalent bonding and lack of Group 15 precursors. While the coreduction method with commercially available arsenic precursors enables facile syntheses of InAs QDs, it results in broad size distributions requiring subsequent size-selection processes. In this study, we introduced zinc ions in the form of coordination complexes during coreduction of the indium and arsenic precursors. The Zn ions chemically passivated the surfaces of the InAs QDs, narrowed the size distribution and removed surface defects. When the InAs QDs were integrated into infrared photodiodes as IR absorbers, the surface-attached Zn ions electrically modulated the energy level and carrier concentration. Infrared photodiodes with the InAs:Zn QD layers exhibited dark currents and photoresponses that were two orders of magnitude lower and approximately twice as fast, respectively, as those seen for bare InAs QDs.

Nanoengineering multifunctional extracellular vesicles availably mitigate bone loss in osteoporosis through binding to RANKL and rebalancing the Treg/Th17 cells

The balance between regulatory T cells (Treg) and T helper 17 cells (Th17) plays an important role in bone loss in osteoporosis. Hyperactivation of Th17 cells, where a large amount of cytokine RANKL is secreted, promotes the osteoclast phenotype. The restoration of immune homeostasis of Treg/Th17 cells could inhibit bone loss. However, the engineered strategy is still absent. Herein, we report an immunomodulatory bioactive glass nanoparticle-engineered bone marrow-derived macrophages (BMDMs) to generate extracellular vesicles (SrBGN + Mφ-EVs), which could regulate the Treg/Th17 balance and inhibit the bone loss in osteoporosis. SrBGN + Mφ-EVs contain both SrBGNs immunomodulatory active ions and anti-inflammatory factors of M2-type BMDMs and have good biocompatibility in vitro. SrBGN + Mφ-EVs regulated the Treg/Th17 balance by promoting Treg cell differentiation and inhibiting Th17 cell differentiation in vitro. More importantly, more RANK was enriched on the surface of SrBGN + Mφ-EVs with strong affinity to RANKL, which acted as a competitive inhibitor of RANKL-RANK interaction and inhibited the activation of osteoclasts. In vivo experiments, SrBGN + Mφ-EVs showed excellent biocompatibility and improved the immune environment of osteoporotic mice to inhibit bone loss. This study may provide new ideas for the regulatory strategy of bioactive glass and its engineered extracellular vesicles in re-establishing immune homeostasis in osteoporosis, as well as a solution for treating bone resorption disorders.

A 3D-Printed Wound-Healing Material Composed of Alginate Dialdehyde-Gelatin Incorporating Astaxanthin and Borate Bioactive Glass Microparticles.

In this study, a wound dressing composed of an alginate dialdehyde-gelatin (ADA-GEL) hydrogel incorporated by astaxanthin (ASX) and 70B (70:30 B2O3/CaO in mol %) borate bioactive glass (BBG) microparticles was developed through 3D printing. ASX and BBG particles stiffened the composite hydrogel construct and delayed its in vitro degradation compared to the pristine hydrogel construct, mainly due to their cross-linking role, likely arising from hydrogen bonding between the ASX/BBG particles and ADA-GEL chains. Additionally, the composite hydrogel construct could hold and deliver ASX steadily. The composite hydrogel constructs codelivered biologically active ions (Ca and B) and ASX, which should lead to a faster, more effective wound-healing process. As shown through in vitro tests, the ASX-containing composite hydrogel promoted fibroblast (NIH 3T3) cell adhesion, proliferation, and vascular endothelial growth factor expression, as well as keratinocyte (HaCaT) migration, thanks to the antioxidant activity of ASX, the release of cell-supportive Ca2+ and B3+ ions, and the biocompatibility of ADA-GEL. Taken together, the results show that the ADA-GEL/BBG/ASX composite is an attractive biomaterial to develop multipurposed wound-healing constructs through 3D printing.

Structure and persistent luminescence of novel Pr-doped Mg3Lu2Ge3O12 garnet

Garnet-based materials are widely investigated for applications in optics. In this research, we report the structure and spectroscopic properties of novel Mg3Lu2Ge3O12: Pr3+ garnet that exhibits orange persistent luminescence. The atomic positions of Mg3Lu2Ge3O12 were calculated using Rietveld refinement. The local structure analysis using extended X-ray absorption fine structure (EXAFS) and site-selective spectroscopy revealed that activator ions predominantly incorporate in the Lu3+ position. The persistent luminescence processes in Mg3Lu2Ge3O12: Pr3+ were analysed using photoluminescence (PL), thermostimulated luminescence (TSL), and electron paramagnetic resonance (EPR) spectroscopy methods. The comparison of PL and persistent luminescence spectra imply that electron and hole traps are filled due to the photoionization of Pr3+ ions. Two paramagnetic defects related to O- sites were detected after the excitation. TSL analysis indicates a quasi-continuous charge trap distribution ranging from 0.57 to 1.51 eV in the investigated host, enabling efficient persistent luminescence. The persistent luminescence mechanism of Mg3Lu2Ge3O12: Pr3+ is proposed.

The simulation of active ions luminescence in the preform core under the pumping through the lateral surface

A description of the model of luminescence of active erbium ions in the core of an optical fiber with subsequent experimental verification is presented. The author suggested a verification technique based on local irradiation of the erbium-doped medium at the dopant absorption wavelength and subsequent registration of the power of induced luminescence. These data are necessary to establish the physical limit of the detection frequency of the system for analyzing the distribution of active erbium ions in the preform of the optical fiber. Calculations showed that the order of values of the luminescence steady-state duration is 10 ms, which agrees with the experimental results and other references. Thus, it was found that the fundamental limit of the acquisition frequency of any system investigating the luminescence properties of erbium cannot exceed 200 Hz. The phenomenon of parasitic back reflection from the preform was also simulated. In the future, this may help to further optimize the measurement process.

Activation of silver nanoparticles by hydrophilic encapsulation for antimicrobial powder coated surfaces

Silver nanoparticles (AgNP) are known as an antimicrobial agent, but they cannot be efficiently converted to active silver ions due to the lack of hydrophilic reaction environment when incorporated into a dry powder coating film. To make these agents effective in the powder coated surface, a novel encapsulation approach was proposed. Silver nanoparticles were first synthesized on the surface of synthetic zeolite A by in-situ chemical reduction method, which was followed by the addition of copper ions through ion exchange. The functionalized zeolite was then encapsulated with different water-soluble hydrophilic polymers to facilitate the generation of silver ions from nanoparticles. The encapsulated additives were incorporated into the resin system for making the antimicrobial powder coating film. The properties of the additives and films were carefully analyzed, and results show that appropriate loading of silver guarantees a high concentration and uniform distribution of silver nanoparticles on the zeolite surface. The strength of the encapsulation with the additive is found to depend on the cations present in the additives. Anionic polymer encapsulation is the most effective solution for releasing silver ions from antimicrobial coated surface. Excessive hydrophilicity is not beneficial to antimicrobial ability and brings cracks on the surface. Additives with non-polymeric hydrophilic encapsulation made from the precipitation of calcium nitrate and sodium phosphate also shows acceptable antimicrobial efficiency. The proposed hydrophilic encapsulation method can well facilitate the activation of silver nanoparticles and ensure an effective antimicrobial property of the powder coating film.

Halide Double Perovskite Nanocrystals Doped with Rare-Earth Ions for Multifunctional Applications.

Most lead-free halide double perovskite materials display low photoluminescence quantum yield (PLQY) due to the indirect bandgap or forbidden transition. Doping is an effective strategy to tailor the optical properties of materials. Herein, efficient blue-emitting Sb3+ -doped Cs2 NaInCl6 nanocrystals (NCs) are selected as host, rare-earth (RE) ions (Sm3+ , Eu3+ , Tb3+ , and Dy3+ ) are incorporated into the host, and excellent PLQY of 80.1% is obtained. Femtosecond transient absorption measurement found that RE ions not only served as the activator ions but also filled the deep vacancy defects. Anti-counterfeiting, optical thermometry, and white-light-emitting diodes (WLEDs) are exhibited using these RE ions-doped halide double perovskite NCs. For the optical thermometry based on Sm3+ -doped Cs2 NaInCl6 :Sb3+ NCs, the maximum relative sensitivity is 0.753% K-1 , which is higher than those of most temperature-sensing materials. Moreover, the WLED fabricated by Sm3+ -doped Cs2 NaInCl6 :Sb3+ NCs@PMMA displays CIE color coordinates of (0.30, 0.28), a luminous efficiency of 37.5lm W-1 , a CCT of 8035 K, and a CRI over 80, which indicate that Sm3+ -doped Cs2 NaInCl6 :Sb3+ NCs are promising single-component white-light-emitting phosphors for next-generation lighting and display technologies.

Designing hybrid-guidance large mode area fiber for high-power lasers

All-solid large-mode-area antiresonant fibers possess unique characteristics of broadband, low-loss transmission of fundamental mode with effective single mode operation. Hinging on the principle, we propose a unique hybrid guidance mechanism, combining antiresonant guidance with total internal reflection-based guidance to design bend-tolerant, ultra large mode field area (>3000 µm2) fibers for high-power laser applications. Low-index rods are strategically interspersed into the antiresonant cladding to enhance the modal confinement in the fiber, resulting in lower confinement loss of the fundamental mode and its increased tolerance to bending and to the refractive index dip caused by non-uniform doping of active ions in the fiber core. We show that total internal reflection guidance greatly helps confine the fundamental mode without masking the characteristic features of antiresonant guidance, like effective single mode operation over broad spectral bandwidth. We present a detailed theoretical analysis to design a bendable, effectively single-moded passive and active hybrid-guidance antiresonant fibers, optimized to work in the 1 µm wavelength band. The design principles are universal and can be extended to shift the operating wavelength to the 2 µm range as well.

Effective time of a diffusion source in a pack cementation process on the AZ91D magnesium alloy

The powder thermal diffusion alloying method is an important method to fabricate intermetallic coatings on magnesium alloy substrates. The diffusion source, the diffusion time and the diffusion temperature are key parameters for a diffusion alloying process. While the effective time of an active diffusion source at the diffusion temperature is still unclear. Clarification of the effective time of a diffusion source is important, as the diffusion source could be utilized effectively and economically only if the effective time of the active diffusion source is known. Here, the effective time of a diffusion source at 400 °C was investigated. Results show that, the effective time of the diffusion source which contains 10 g ZnO and 1 g NH4Cl is around 150 h at 400 °C. For a more compact diffusion source, the effective time is relatively shorter. Then, chemical reactions in the diffusion source at elevated temperature were analyzed. The failure of the diffusion source is related to the reduction in the number of active metal ions, while an ineffective diffusion source can be reactivated by addition of new halide powder. These results could deepen the understanding of the role of the diffusion source in a powder thermal diffusion alloying process and indicate a limit under which the diffusion source could be utilized effectively.

A novel smart coating with hexacyanoferrate intercalated layered double hydroxides nanoadditive for early detection of carbon steel corrosion

The detection of corrosion at early stages could increase the service life of metal-based infrastructures in a cost-effective manner. Despite the recent progress in “smart” self-reporting corrosion sensing coatings, the development of environmentally friendly systems appropriate for steel substrate used in offshore applications remains a relevant challenge. In this study, a novel smart corrosion sensing coating, based on hexacyanoferrate intercalated Mg-Al LDH nanoadditive, was developed, aiming at the detection of early-stage corrosion of carbon steel. The detection mechanism is based on the ability of hexacyanoferrate ions to react with iron cations generated during the corrosion process, giving rise to a colorimetric signal, while LDH carriers provide a controlled release of active ions under corrosion conditions. The sensing nanoadditive was embedded into a commercial pigment-free water-based acrylic polyurethane coating. The nanomaterial was characterized structurally (XRD) and morphologically (STEM). The compatibility of the additive with the polymer formulation and its influence on the resulting coating performance was investigated in terms of rheological behavior, structure (FTIR), morphology (SEM/EDS), thermal (TGA, DSC) and mechanical (adhesion, hardness) properties. The corrosion protection ability of the coating was evaluated via EIS, while the sensing functionality was analyzed by visual analysis of the surface. The developed coating successfully detects early-stage corrosion of steel substrate at a lab scale, in conditions relevant to the use of metallic structures in offshore applications, demonstrating a correlation between the level of material degradation and the spectroscopic signal associated with the presence of the LDH functional nanoadditive. Furthermore, the observed decrease in coating barrier properties, caused by the presence of LDH, was overcome by the subsequent development of a multilayer coating system. Two different topcoats (epoxy- and polyurethane-based) were surveyed for this purpose, showing an improvement in the coating barrier properties without influencing the corrosion detection functionality of the sensing layer. The results were successfully validated by standard salt spray tests. The multilayer approach opens up the possibility to model coatings with different characteristics for various operating conditions.

Transparent Gd3Al2Ga3O12 nanocrystals/glass system: Al2O3 enhanced photoluminescence and optical nonlinearity

Nanocrystals doped transparent materials have shown promising enhanced optical absorption and luminescence properties. In this study, we report the in-situ crystallization of Gd3Al2Ga3O12 in tellurite glass under the modification of Al2O3, and the influence on glass network structure and optical performances as a function of the size, coordination states, crystal structure, and defects of nanocrystals Gd3Al2Ga3O12 garnet (GAGG). 10-20 nm-cubic Gd3Al2Ga3O12 (Ia3d space group) nanocrystals formed in glass whose size increased with the Al2O3 content. Due to the existence of nanocrystals Gd3Al2Ga3O12, Sm3+ containing glass showed enhanced 9 absorption bands due to electron transitions of activator ions. In addition, Al2O3-activated GAGG crystallization decreased the Eg of glass, resulting in greatly improved red luminescence at 600 nm. The CIE chromaticity diagram revealed good luminescence stability. The polarizability was significantly increased which contributed to the huge third-order nonlinear behaviors. As Al2O3 increased, the χ(3) and n2 increased while the optical limiting threshold decreased. Glass A75 exhibited excellent optical linear, nonlinear, and emission properties which are promising for photonics device applications.

Ultra-high-performance aluminum-based hybrid supercapacitors prepared for nitrogen-doped micro-mesoporous carbon sphere

Aluminum-based devices are promising candidates for the next generation of energy storage due to the advantages of high energy density, high safety, and low cost. The aluminum ion batteries (AIBs) are based on the electrochemical intercalation/deintercalation reactions against the electrodes, but the selection of the cathode is limited to the present. The cathode reactions of cation-type AIBs are plagued by the poor kinetics of solid-state diffusion from high charge density of Al3+ and anion-type AIBs show poor capacity due to the intercalation of large-sized chloroaluminate (AlCl4−) active ions into the cathode. Here, we deliberately adopted a hybrid capacitor-battery mechanism and employed a nitrogen-doped micro-mesoporous carbon sphere of a high specific area as the cathode and aluminum as the anode to construct an aluminum-based energy storage device. After optimization, it exhibits an excellent discharge capacity of 224 mA h g−1 at a current density of 300 mA g−1, and exceptional cycling performance with a discharge capacity as high as 114 mA h g−1 at 10 A g−1 after 35000 cycles. The ultra-high-performance aluminum-based hybrid supercapacitor (Al-HSC) may lead to a new direction for the development of aluminum-based energy storage devices.