High Retention Efficiency Research Articles

Sn/SnOx core-shell structure encapsulated in nitrogen-doped porous carbon frameworks for enhanced lithium storage

Sn-based materials are promising as high-capacity anode materials for lithium-ion batteries. A novel Sn/carbon composite is obtained facilely by using Sn-based metal-organic frameworks and dicyandiamide as precursors. The composites are composed of Sn/SnOx core-shell microspheres encapsulated in 3D porous nitrogen-doped carbon frameworks (denoted as Sn/SnOx@NC). When used as anode material for lithium-ion batteries, the Sn/SnOx@NC composite exhibites a high reversible capacity of 817.8 mA h g−1 at 100 mA g−1 after 200 cycles and 525.7 mA h g−1 at 1 A g−1 after 800 cycles. It also exhibits high capacity retention and high Coulombic efficiency. The excellent electrochemical performance can be primarily ascribed to the peculiar porous N-doped carbon frameworks, which can effectively buffer the huge volume change of Sn and promote the transmission of electrons and Li+, thereby indicating its potential for use as an anode material for Li-ion batteries.

High-Performant All-Organic Aqueous Sodium-Ion Batteries Enabled by PTCDA Electrodes and a Hybrid Na/Mg Electrolyte.

Aqueous sodium‐ion batteries (ASIBs) are aspiring candidates for low environmental impact energy storage, especially when using organic electrodes. In this respect, perylene‐3,4,9,10‐tetracarboxylic dianhydride (PTCDA) is a promising anode active material, but it suffers from extensive dissolution in conventional aqueous electrolytes. As a remedy, we here present a novel aqueous electrolyte, which inhibits the PTCDA dissolution and enables their use as all‐organic ASIB anodes with high capacity retention and Coulombic efficiencies. Furthermore, the electrolyte is based on two, hence “hybrid”, inexpensive and non‐fluorinated Na/Mg‐salts, it displays favourable physico‐chemical properties and an electrochemical stability window >3 V without resorting to the extreme salt concentrations of water‐in‐salt electrolytes. Altogether, this paves the way for ASIBs with both relatively high energy densities, inexpensive total cell chemistries, long‐term sustainability, and improved safety.

High‐Performant All‐Organic Aqueous Sodium‐Ion Batteries Enabled by PTCDA Electrodes and a Hybrid Na/Mg Electrolyte

AbstractAqueous sodium‐ion batteries (ASIBs) are aspiring candidates for low environmental impact energy storage, especially when using organic electrodes. In this respect, perylene‐3,4,9,10‐tetracarboxylic dianhydride (PTCDA) is a promising anode active material, but it suffers from extensive dissolution in conventional aqueous electrolytes. As a remedy, we here present a novel aqueous electrolyte, which inhibits the PTCDA dissolution and enables their use as all‐organic ASIB anodes with high capacity retention and Coulombic efficiencies. Furthermore, the electrolyte is based on two, hence “hybrid”, inexpensive and non‐fluorinated Na/Mg‐salts, it displays favourable physico‐chemical properties and an electrochemical stability window >3 V without resorting to the extreme salt concentrations of water‐in‐salt electrolytes. Altogether, this paves the way for ASIBs with both relatively high energy densities, inexpensive total cell chemistries, long‐term sustainability, and improved safety.

Fabricating nanostructured HoFeO3 perovskite for lithium-ion battery anodes via co-precipitation

Nanostructured HoFeO3 perovskite was successfully prepared via co-precipitation of Fe3+ and Ho3+ ions in ethanol, followed by heat treatment. Analysis revealed the orthorhombic structure, uniaxial orientation, and nanograin size. This anode material exhibited excellent electrochemical properties in lithium-ion batteries including high capacity retention and Coulombic efficiency, good cyclability, low charge transfer, high Li+ diffusion coefficient, and excellent rate performance. They delivered reversible capacity of 437 mAh g−1 after 120 cycles at current density of 0.1 A g−1, a charge capacity of 299 mAh g−1 even at high current density of 10 A g−1. Outstanding performance can be ascribed to unique nanostructured perovskite. Nanosized materials offer a larger electrode/electrolyte interface, and reduce Li-ion diffusion length, improving reaction kinetics. Perovskite structure effectively prevented anode degradation during cycling, demonstrating excellent reversible storage. Kinetics of electrochemical reactions were also studied. All indicate the great potential of HoFeO3 perovskite as an anode material in LIBs.

Viability and stability evaluation of Lactobacillus casei LC03 co-encapsulated with red onion (Allium cepa L.) peel extract

This study aimed to evaluate the effects of adding different concentrations (5, 20, and 40%) of red onion (Allium cepa L.) peel extract to probiotic microparticles on the viability and stability of a Lactobacillus casei LC03 probiotic. The survival of the probiotic under simulated gastrointestinal conditions, its viability in storage, and the resistance of the microparticles to thermal treatments were evaluated, as well as the morphology, size distribution, and encapsulation efficiency of probiotics and compounds in the extract. All microparticle formulations showed high probiotic retention efficiency (>90%). The sizes of the microparticles ranged from 149.29 to 167.05 μm. The treatment containing alginate +20% extract increased probiotic survival under simulated gastrointestinal conditions than the other treatments. It was possible to increase the heat resistance of encapsulated probiotics over free microorganisms. During storage at 25 °C, the alginate microparticles +5 and + 20% extract stood out, whereas the most prolonged period of viability was reached by alginate alone and alginate microparticles +5% extract at 7 °C. At −18 °C, all microparticle formulations remained stable during 90 days of storage. These findings suggest that such microparticles can promote the extended viability and stability of the probiotic L. casei under different conditions.

Plasma treated carbon nanofiber for flexible supercapacitors

Ambient plasma is applied to carbon nanofiber (CNF) and investigated for flexible supercapacitor applications. For the flexible supercapacitor applications, gel electrolyte and nickel foam as a supporting collector electrode were used. The plasma treatment increases active surface area of CNF by three times and decreases electrochemical charge-transfer resistance dramatically from 9.5 to 3.7 Ω. Resultant capacitances of 210 ± 3 Fg−1 and 129 ± 1 Fg−1 (0.5 Ag−1) in three-electrode system and two-electrode system, respectively, are obtained with high specific energy of 11.5 Whkg−1 and specific power of 200 Whkg−1. Finally, it shows reliable flexibility as well as high specific capacitance retention (84%) and coulombic efficiency (81%) after 10,000 cycles. The result demonstrates that the as-prepared materials may be suitable for flexible all-solid-state supercapacitor devices.

Phosphate Electrolyte Design for Highly Reversible Sodium Ion Batteries

Sodium ion battery (NIB) is a very promising technology for the next generation of energy storage systems because of the abundance and low cost of Na in the Earth’s crust. However, the large-scale application of NIBs is still a challenge because of limited cycle life and potential safety concerns. In this regard, electrolyte plays a critical role in both cycle life and safety of NIBs. The battery stability is directly related to the properties of the electrode-electrolyte interphase. Therefore, designing advanced electrolytes with a stable electrode-electrolyte interphase is crucial to develop stable NIBs for their practical applications in large-scale energy storage. In this work, we report a phosphate-based electrolyte for sodium ion batteries with high capacity retention and excellent coulombic efficiency (99.9 %) during long term cycling. The details together with postmortem analysis of the cycled electrode will be discussed at the presentation. The insights obtained in this work can be used to further improve cycling stability and safety of rechargeable batteries.

Macro- and Micronutrient Cycling and Crucial Linkages to Geochemical Processes in Mangrove Ecosystems

High mangrove productivity is sustained by rapid utilization, high retention efficiency and maximum storage of nutrients in leaves, roots, and soils. Rapid microbial transformations and high mineralization efficiencies in tandem with physiological mechanisms conserve scarce nutrients. Macronutrient cycling is interlinked with micronutrient cycling; all nutrient cycles are linked closely to geochemical transformation processes. Mangroves can be N-, P-, Fe-, and Cu-limited; additions of Zn and Mo stimulate early growth until levels above pristine porewater concentrations induce toxicity. Limited nutrient availability is caused by sorption and retention onto iron oxides, clays, and sulfide minerals. Little N is exported as immobilization is the largest transformation process. Mn and S affect N metabolism and photosynthesis via early diagenesis and P availability is coupled to Fe-S redox oscillations. Fe is involved in nitrification, denitrification and anammox, and Mo is involved in NO3− reduction and N2-fixation. Soil Mg, K, Mn, Zn and Ni pool sizes decrease as mangrove primary productivity increases, suggesting increasing uptake and more rapid turnover than in less productive forests. Mangroves may be major contributors to oceanic Mn and Mo cycles, delivering 7.4–12.1 Gmol Mn a−1 to the ocean, which is greater than global riverine input. The global Mo import rate by mangroves corresponds to 15–120% of Mo supply to the oceanic Mo budget.

Development of microcapsules using chitosan and alginate via W/O emulsion for the protection of hydrophilic compounds by comparing with hydrogel beads

It is a critical challenge to protect hydrophilic compounds in food or pharmaceutical applications due to their strong tendency to leak out of the capsules into the external aqueous phase. In this work, we developed an encapsulation system that can protect hydrophilic ingredients using polyelectrolyte complexes prepared with chitosan and alginate via water-in-oil (W/O) emulsion. Unlike the traditional preparation of hydrogel beads, in which one material was added dropwise to another that had an opposite charge, we prepared microcapsules by electrostatic interaction between the positively charged -NH3+ groups of chitosan and the negatively charged -COO− groups of alginate by W/O emulsion via ultrasonication, which prevented the formation of large complexes. The preparation conditions were optimized at an ultrasonic power of 375 W and alginate/chitosan ratio of 7:5, in which the alginate/chitosan microcapsules presented a good polydispersity index of 0.26 and zeta potential of −44.6 mV. The SEM and TEM images showed the microcapsule contained multiple, irregular, conglutinated spheres with a core and shell structure. High encapsulation efficiency and retention efficiency showed its potential to protect hydrophilic components from harsh environments. This method provides a simple route that can efficiently encapsulate a wide range of food or pharmaceutical hydrophilic ingredients.

An investigation of calcium carbonate core-shell particles for incorporation of 225Ac and sequester of daughter radionuclides: in vitro and in vivo studies

Alpha therapy provides an outstanding prospect in the treatment of recalcitrant and micrometastatic cancers. However, side effects on the normal tissues and organs (especially, kidneys) due to the release of daughter isotopes from α-emitters remain a bottleneck. In this work, calcium carbonate core-shell particles of different sizes were considered as isotope carriers for encapsulation of 225Ac (highly powerful alpha-emitter that generates 4 net alpha particle isotopes in a short decay chain) in order to achieve in vitro and in vivo retention of 225Ac and its daughter isotopes. According to the in vitro studies, the developed calcium carbonate core-shell particles were able to retain 225Ac and its daughter isotopes (221Fr and 213Bi) exhibited good stability in biological media and dose-dependent biocompatibility (over 30 d). The SPECT imaging demonstrated the size-dependent distribution of 225Ac-doped core-shell particles. Further, in vivo studies confirmed the high retention efficiency of calcium carbonate core-shell particles, which was demonstrated in normal Wistar rats (up to 10 d). Interestingly, the radioactivity accumulation in kidney and urine was significantly less for encapsulated 225Ac than in case of non-encapsulated form of 225Ac (225Ac conjugated with albumin), indicating the absence of radioisotope leakage from the developed particles. Thus, our study validates the application of 225Ac-doped core-shell particles to sequester α-emitter (225Ac) and its decay products in order to reduce their systemic toxicity during alpha therapy.

Effects of Shallow Water Table Depth on Vegetative Filter Strips Retarding Transport of Nonpoint Source Pollution in Controlled Flume Experiments

Vegetative filter strips (VFSs) have been recommended as the best management practice for reducing runoff nonpoint source (NPS) pollution. The efficiency of VFSs located adjacent to water bodies can vary with shallow water table depths (WTD). A vegetated soil tank containing silt loam soil and Shortleaf Lilyturf vegetation was designed to study the effects of VFSs under shallow WTD (0.08, 0.22, and 0.36 m) on retentions of surface runoff, sediment, phosphorus, and bromide. Experiments were conducted with a simulated rainfall intensity of 28 mm h−1 and inflow rates of 4.02–4.56 L min−1. The results revealed that a deep WTD, low grass spacing, and low slope had high VFS retention efficiencies. The retention efficiencies varied greatly from 35%, 70%, 64%, and 55% at the 0.08-m WTD in the experimental group with high grass spacing (6.69 cm) and low slope (5%) to 96%, 98%, 96%, and 95% at the 0.36-m WTD in the experimental group with low grass spacing (4.18 cm) and low slope (5%) for surface runoff, sediment, phosphorus, and bromide, respectively. A steeper slope (at the same grass spacing) increased the effects of the WTD on VFS performance. For each experimental group, the average surface runoff outflow rate decreased with the WTD, whereas the average subsurface lateral flow rate increased. The transport of phosphorus in the surface runoff almost resembled that of bromide, and the average concentration (C/C0 Ave) of phosphorus and bromide decreased with the WTD. For the subsurface lateral flow, the transport of bromide and phosphorus exhibited typical breakthrough behaviors during each experiment, and both the normalized phosphorus and bromide concentrations in increasing limbs could be described by power equations. The high concentration of pollutants in the subsurface lateral flow may have affected the adjacent water bodies and groundwater. In quantification of the impact of WTD on effectiveness of VFS, we can effectively control the NPS pollutants in a watershed.

Fabricating Nanostructured HoFeO <sub>3</sub> Perovskite for Lithium-Ion Battery Anodes via Co-Precipitation

Nanostructured HoFeO3 perovskite was successfully prepared via co-precipitation of Fe3+ and Ho3+ ions in ethanol, followed by heat treatment. Analysis revealed the orthorhombic structure, uniaxial orientation, and nanograin size. This anode material exhibited excellent electrochemical properties in lithium-ion batteries including high capacity retention and Coulombic efficiency, good cyclability, low charge transfer, high Li+ diffusion coefficient, and excellent rate performance. They delivered reversible capacity of 437 mAh g-1 after 120 cycles at current density of 0.1 A g-1, a charge capacity of 299 mAh g-1 even at high current density of 10 A g-1. Outstanding performance can be ascribed to unique nanostructured perovskite. Nanosized materials offer a larger electrode/electrolyte interface, and reduce Li-ion diffusion length, improving reaction kinetics. Perovskite structure effectively prevented anode degradation during cycling, demonstrating excellent reversible storage. Kinetics of electrochemical reactions were also studied. All indicate the great potential of HoFeO3 perovskite as an anode material in LIBs.

Synthesis of nitrogen-doped plasma treated carbon nanofiber as an efficient electrode for symmetric supercapacitor

A nitrogen-doped plasma treated carbon nanofiber is prepared by using melamine and ambient plasma for supercapacitor applications. Nitrogen of 11 wt% was doped, and electrochemical active surface area increased by almost four times, compared to precursor CNF, resulting that high specific capacitance of 495 Fg−1 at 0.5 Ag−1, which is more than six times larger than 73 Fg−1 of CNF, with remarkable rate capability and cyclic stability was obtained. Electrochemical impedance is also dramatically reduced from 249 to 24 Ω at 100 Hz. Specific energies of 21 Whkg−1 and 12.2 Whkg−1 at the specific power of 200 Wkg−1 and 4,000 Wkg−1, respectively, were obtained with high capacitance retention (94%) and coulombic efficiency (92%) after 10,000 cycles. The results demonstrate that the as-prepared electrode can be a good alternative electrode material for stable and reliable supercapacitors.

Artificial Lithium Isopropyl-Sulfide Macromolecules as an Ion-Selective Interface for Long-Life Lithium-Sulfur Batteries.

The persistent reduction reactions between the hyperactive lithium metal (Li) and dissolved polysulfides would passivate the Li metal and rapidly decrease the cathodic active materials, thus leading to low Coulombic efficiency and a short cycle life of lithium-sulfur (Li-S) batteries. Herein, we construct artificial lithium isopropyl-sulfide macromolecules as an ion-selective interface on the Li metal (IS-Li) by a facile electrochemical polymerization method, in which the polymer network improves the elasticity and toughness to accommodate the volume change of the Li anode and the formed lithium-organosulfides provide great mechanical strength to resist the destruction of Li dendrites. Importantly, this interfacial layer is proved to be sufficient in damping polysulfide anion diffusion and stopping irreversible reduction between polysulfides and metallic Li, which greatly contribute to the performance improvement of Li-S batteries. The resulting Li-S batteries exhibit long-term stability with high capacity retention and Coulombic efficiency. This effective strategy sets a new approach for regulating the interfacial chemistry of Li metal anodes, which is significant for highly stable Li-S batteries.

Redox chemistry of nitrogen-doped CNT-encapsulated nitroxide radical polymers for high energy density and rate-capability organic batteries

To enhance the electrochemical performance and identify the redox reaction of a nitroxide radical-based organic battery, poly(2,2,6,6-tetramethylpiperidinyloxy-4-vinylmethacrylate) (PTMA) as nitroxide radical polymer is synthesized and used to fill the central pore of nitrogen-doped carbon nanotubes (NCNTs). The PTMA-filled NCNTs demonstrate high rate capability, stable cycling, and high electrode stability, owing to their high charge transfer and ion diffusion; further, they prevent the dissolution of organic active material. The nitrogen doping on CNTs improves the electrochemical properties by created defects. The PTMA-filled NCNT cells have a high reversible capacity of 199.8 mAh g−1 and high energy density of 489.4 Wh kg−1 on electrode level at 0.2C with a two-step redox couple. Moreover, the cells with the two-step redox couple exhibit excellent stable cycle performance with high capacity retention and Coulombic efficiency for 3000 cycles. The nitroxide radical of PTMA can be converted to either an oxoammonium cation or an aminoxy anion; further, the redox reaction of each step exhibits different performance. The nitroxide radical–oxoammonium cation redox step in NCNTs shows a high rate capability owing to the high charge transfer rate and ion diffusion coefficient. The unusual results will help further improve the properties and commercialization of rechargeable organic batteries.

Stabilize lithium metal anode through constructing a lithiophilic viscoelastic interface based on hydroxypropyl methyl cellulose

Due to higher theoretical specific capacity and lower electrochemical redox potential, lithium metal is considered an ideal anode material for high specific energy batteries. However, safety problems related to the uncontrolled growth of lithium dendrites and the volume expansion of lithium have hindered its commercialization. This paper reports a viscoelastic interface based on viscoelastic polymer (hydroxypropyl methyl cellulose) to protect lithium metal anode. The lithiophilic interface has good chemical, electrochemical and mechanical stability, which makes the dendrite-free and low volume expansion lithium possible. The Li/Li symmetrical battery based on anode protected by viscoelastic interface show better cycle stability and longer cycle life. The morphologies after cycles show a relatively smooth and dense lithium deposition. Li/LFP full battery test results show higher reversible capacity at higher C-rate, high capacity retention (85.2%) and stable coulomb efficiency (99.5%) at 0.2C after 200 cycles. This work provides insight into the strategy of interfacial engineering to protect lithium metal anode.

Dietary butyrate alone or in combination with succinate and fumarate improved survival, feed intake, growth and nutrient retention efficiency of juvenile Penaeus monodon

Organic acids and their salts have been used in commercial aquafeeds as an alternative to antibiotics, growth promoters and their effect on performance and survival continue to be investigated in aquatic organisms including shrimp with a few reports on Penaeus monodon. We assessed production performance and nutrient retention efficiency of juvenile black tiger shrimp fed diets supplemented without (control – CON) or with organic acids (butyrate - BUT, succinate – SUC, and fumarate - FUM) individually (10 g kg−1) or in combination (ALL; 30 g kg−1). After 42 days, survival was significantly higher in the BUT and ALL treatments compared to the CON (98% and 90% vs. 70%; P < .01). Addition of BUT, SUC, and ALL reduced feed conversion ratio compared to the CON group (1.3–1.7 vs. 2.4; P < .01). Biomass gain in BUT and ALL feeds was statistically higher than the rest of the dietary treatments (28.3 g vs. 11.2–19.1 g; P < .01). Non-linear and linear regressions displayed a strong relationship between biomass gain and total feed intake across dietary treatments with R2 varying from 0.71 to 0.99. The supplementation of SUC, BUT, and ALL increased the overall nutrient retention efficiency (RE) in comparison to the CON, with BUT and ALL displaying the highest RE for all tested macronutrients (e.g., crude protein = 26.7% and 24.6% vs. 15.3%, total lipid = 19.2% and 17.7% vs. 10.6%, ash = 25.1% and 23.1% vs. 12.1%, and gross energy = 17.7% and 16.3% vs. 10.2%). In summary, supplementation of ALL organic acids (fumarate, butyrate, and succinate) improved survival, feed intake, growth, and nutrient retention efficiency of juvenile P. monodon. Individually, BUT appears to be the most potent organic acid followed by SUC, whereas the use FUM isn't justified in P. monodon diets.

Application of spherical polyelectrolyte brushes microparticle system in flocculation and retention.

In this paper, a microparticle system consisting of cationic polyacrylamide (CPAM) and anionic spherical polyelectrolyte brushes (ASPB) is proposed to improve the retention of pulp suspension containing bleached reed kraft pulp and precipitated calcium carbonate (PCC). We first describe the preparation of ASPB. The ASPB, consisting of a carbon sphere (CS) core and a shell of sodium polystyrene sulfonate (PSSNa) brushes, was synthesized by surface-initiated polymerization. The structure and morphology of ASPB were characterized by Fourier-transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Then, flocculation and retention of pulp suspension by a CPAM/ASPB dual-component system were examined. Our results indicate that more highly effective flocculation and higher retention efficiency could be achieved simultaneously by a CPAM/ASPB dual-component system when compared to the conventional microparticle system. Bridging flocculation and electrostatic attraction might be the main flocculation mechanism for CPAM/ASPB systems.

Geochemical interactions in the trace element-soil-clay system of treated contaminated soils by Fe-rich clays.

Clays have been widely applied in contaminated soils in order to reduce the mobility of potentially toxic elements (PTEs), such as Pb, Zn and Cu. In the present study, three Fe-rich clays from Greece were selected as amendments of three contaminated soils with distinct physicochemical and mineralogical characteristics. The amendments consisted of palygorskite-rich (PCM), Fe-smectite-rich (SCM) and natural palygorskite/Fe-smectite-rich (MCM) clays. The changes induced in the environment of the soil-PTE-clay system were assessed by examining the water-labile fraction of Pb, Zn and Cu, as well as the bioaccessibility of Pb, in the contaminated soils. The initial water-leachable concentrations of PTEs in soil were within the range 1826-6160μg/kg Pb, 152-645μg/kg Cu and 370-4052μg/kg Zn. All three Fe-rich clays exhibited high retention efficiency toward PTEs, following the order Pb (55-70%) > Zn (45-55%) > Cu (0-45%). The high reactive surface area of the clay particles acted as a substrate for the deposition of Fe-Al oxides with a concomitant removal of PTEs that were transported through the colloidal fraction. Furthermore, the decrease in relative bioaccessibility of Pb (5-10% compared to the control) suggests dissolution of primary clays followed by entrapment of the element in secondary Fe-rich precipitates. In conclusion, the use of Fe-rich clays as soil amendments may have a positive effect in reducing the environmentally significant PTE fraction in soils, especially when different clay phases coexist.

Auto-affitech: an automated ligand binding affinity evaluation platform using digital microfluidics with a bidirectional magnetic separation method.

The dissociation constant (Kd) is a crucial parameter for characterizing binding affinity in molecular recognition, including antigen-antibody, DNA-protein, and receptor-ligand interactions. However, conventional methods for Kd characterization usually involve a multi-step process and time-consuming operations for incubation, washing, and detection, thus causing problems, such as time delays, microbead loss, degradation of sensitive molecules, and personal errors. Here we demonstrate an automated ligand binding affinity evaluation platform (Auto-affitech) using digital microfluidics (DMF), with individual droplets at the microliter level, programmed to rapidly perform the incubation and separation of target-beads and binding ligands. Because the loss of the beads influences the detection results, we propose a new strategy for magnetic bead separation using DMF, termed the bidirectional separation method. By splitting one droplet into two asymmetric droplets, high bead retention efficiency (89.57% ± 0.05%) and high washing efficiency (99.59% ± 0.17%, with four washings) were obtained. We demonstrate the determination of Kd of an aptamer-protein system (EpCAM and its corresponding aptamer SYL3C) and an antigen-antibody system (H5N1 antigen and antibody), proving the capability and universality of Auto-affitech in various receptor-ligand systems. Integrating all the sample processing procedures, the Auto-affitech not only saves manual labor and minimizes personal errors, but also conserves samples and shortens analysis time. Overall, this platform successfully demonstrates to be an automated approach for dissociation constant evaluation and exhibits great potential for highly efficient screening of ligands.