Bone mineral density in children,adolescents and adults with glycogen storage disease type Ia: a cross-sectional and longitudinal study

The occurrence of (symptoms related to) osteopenia is a known complication in glycogen storage disease type Ia (GSD Ia) patients. However, only limited information is available about bone mineral density (BMD). Using dual energy x-ray absorptiometry, we studied both cross-sectional and longitudinal lumbar spine areal BMD (BMD_areal in g/cm²), areal BMD corrected for delayed bone maturation (BMD_{bone age} in g/cm²), and volumetric BMD (BMD_vol in g/cm³). Prepubertal GSD Ia patients (n = 8) had normal BMD (median z-scores BMD_areal -0.6, BMD_{bone age} -0.5 and BMD_vol - 0.5), whereas adolescent patients (n = 12) and adult patients (n = 9) had significantly reduced BMD (BMD_areal -2.3, BMD_{bone age} -1.6, BMD_vol -2.0, and BMD_areal -1.9, BMD_vol-1.5, respectively). Our longitudinal study, showing a stable BMD_areal but a trend to a decrease in BMD_vol in prepubertal patients during follow-up, did not clarify whether the difference in BMD between prepubertal and adolescent/adult patients reflects a diminished accretion of BMD during childhood or reflects historica l differences in treatment. In adolescent and adult GSD Ia patients, BMD_areal and BMD_vol were reduced but stable during follow-up. Especially patients with delayed bone maturation were at risk for reduced BMD. No correlation between parameters of metabolic control and BMD could be detected. Daily calcium intake was within recommended allowances ranges. Abnormal biochemical results included hypomagnesaemia (29%), hypercalciuria (34%) and reduced tubular resorption of phosphate (21%).Although the underlying pathophysiology of reduced BMD in GSD Ia remains unsolved, metabolic control should be optimized to correct as much as possible metabolic and endocrine abnormalitie s that may influence both bone matrix formation and bone mineral accretion. This revised version was published online in August 2006 with corrections to the Cover Date.     

Co-Precipitation Synthesis of Co3[Fe(CN)6]2·10H2O@rGO Anode Electrode for Lithium-Ion Batteries

Rechargeable lithium-ion batteries (LIBs) are known to be practical and cost-effective devices for storing electric energy. LIBs have a low energy density, which calls for the development of new anode materials. The Prussian blue analog (PBA) is identified as being a candidate electrode material due to its facile synthesis, open framework structures, high specific surface areas, tunable composition, designable topologies and rich redox couples. However, its poor electrical conductivity and mechanical properties are the main factors limiting its use. The present study loaded PBA (Co₃[Fe(CN)₆]·10H₂O) on graphene oxide (Co-Fe-PBA@rGO) and then conducted calcination at 300 °C under the protection of nitrogen, which reduced the crystal water and provided more ion diffusion pathways. As a result, Co-Fe-PBA@rGO showed excellent performance when utilized as an anode in LIBs, and its specific capacities were 546.3 and 333.2 mAh g⁻¹ at 0.1 and 1.0 A g⁻¹, respectively. In addition, the electrode also showed excellent performance in the long-term cycle, and its capacity reached up to 909.7 mAh g⁻¹ at 0.1 A g⁻¹ following 100 cycles.     

Micron-Sized Monodisperse Particle LiNi0.6Co0.2Mn0.2O2 Derived by Oxalate Solvothermal Process Combined with Calcination as Cathode Material for Lithium-Ion Batteries

Ni-rich cathode LiNi_xCo_yMn_1-x-yO₂ (NCM, x ≥ 0.5) materials are promising cathodes for lithium-ion batteries due to their high energy density and low cost. However, several issues, such as their complex preparation and electrochemical instability have hindered their commercial application. Herein, a simple solvothermal method combined with calcination was employed to synthesize LiNi_0.6Co_0.2Mn_0.2O₂ with micron-sized monodisperse particles, and the influence of the sintering temperature on the structures, morphologies, and electrochemical properties was investigated. The material sintered at 800 °C formed micron-sized particles with monodisperse characteristics, and a well-order layered structure. When charged–discharged in the voltage range of 2.8–4.3 V, it delivered an initial discharge capacity of 175.5 mAh g⁻¹ with a Coulombic efficiency of 80.3% at 0.1 C, and a superior discharge capacity of 135.4 mAh g⁻¹ with a capacity retention of 84.4% after 100 cycles at 1 C. The reliable electrochemical performance is probably attributable to the micron-sized monodisperse particles, which ensured stable crystal structure and fewer side reactions. This work is expected to provide a facile approach to preparing monodisperse particles of different scales, and improve the performance of Ni-rich NCM or other cathode materials for lithium-ion batteries.     

Enhancement of Y5−xPrxSb3−yMy (M = Sn,Pb) Electrodes for Lithium- and Sodium-Ion Batteries by Structure Disordering and CNTs Additives

The maximally disordered (MD) phases with the general formula Y_5−xPr_xSb_3−yM_y (M = Sn, Pb) are formed with partial substitution of Y by Pr and Sb by Sn or Pb in the binary Y₅Sb₃ compound. During the electrochemical lithiation and sodiation, the formation of Y_5-xPr_xSb_3-yM_yLi_z and Y_5−xPr_xSb_3−yM_yNa_z maximally disordered–high entropy intermetallic phases (MD-HEIP), as the result of insertion of Li/Na into octahedral voids, were observed. Carbon nanotubes (CNT) are an effective additive to improve the cycle stability of the Y_5−xPr_xSb_3−yM_y (M = Sn, Pb) anodes for lithium-ion (LIBs) and sodium-ion batteries (SIBs). Modification of Y_5−xPr_xSb_3−ySn_y alloys by carbon nanotubes allowed us to significantly increase the discharge capacity of both types of batteries, which reaches 280 mAh · g⁻¹ (for LIBs) and 160 mAh · g⁻¹ (for SIBs), respectively. For Y_5−xPrxSb_3−yPb_y alloys in which antimony is replaced by lead, these capacities are slightly smaller and are 270 mAh · g⁻¹ (for LIBs) and 155 mAh · g⁻¹ (for SIBs), respectively. Results show that structure disordering and CNT additives could increase the electrode capacities up to 30% for LIBs and up to 25% for SIBs.     

Effect of Residual Trace Amounts of Fe and Al in Li[Ni1/3Mn1/3Co1/3]O2 Cathode Active Material for the Sustainable Recycling of Lithium-Ion Batteries

As the explosive growth of the electric vehicle market leads to an increase in spent lithium-ion batteries (LIBs), the disposal of LIBs has also made headlines. In this study, we synthesized the cathode active materials Li[Ni_1/3Mn_1/3Co_1/3]O₂ (NMC) and Li[Ni_1/3Mn_1/3Co_1/3Fe_0.0005Al_0.0005]O₂ (NMCFA) via hydroxide co-precipitation and calcination processes, which simulate the resynthesis of NMC in leachate containing trace amounts of iron and aluminum from spent LIBs. The effects of iron and aluminum on the physicochemical and electrochemical properties were investigated and compared with NMC. Trace amounts of iron and aluminum do not affect the morphology, the formation of O3-type layered structures, or the redox peak. On the other hand, the rate capability of NMCFA shows high discharge capacities at 7 C (110 mAh g⁻¹) and 10 C (74 mAh g⁻¹), comparable to the values for NMC at 5 C (111 mAh g⁻¹) and 7 C (79 mAh g⁻¹), respectively, due to the widened interslab thickness of NMCFA which facilitates the movement of lithium ions in a 2D channel. Therefore, iron and aluminum, which are usually considered as impurities in the recycling of LIBs, could be used as doping elements for enhancing the electrochemical performance of resynthesized cathode active materials.     

Improving Fast Charging-Discharging Performances of Ni-Rich LiNi0.8Co0.1Mn0.1O2 Cathode Material by Electronic Conductor LaNiO3 Crystallites

Fast charging-discharging is one of the important requirements for next-generation high-energy Li-ion batteries, nevertheless, electrons transport in the active oxide materials is limited. Thus, carbon coating of active materials is a common method to supply the routes for electron transport, but it is difficult to synthesize the oxide-carbon composite for LiNiO₂-based materials which need to be calcined in an oxygen-rich atmosphere. In this work, LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) coated with electronic conductor LaNiO₃ (LNO) crystallites is demonstrated for the first time as fast charging-discharging and high energy cathodes for Li-ion batteries. The LaNiO₃ succeeds in providing an exceptional fast charging-discharging behavior and initial coulombic efficiency in comparison with pristine NCM811. Consequently, the NCM811@3LNO electrode presents a higher capacity at 0.1 C (approximately 246 mAh g⁻¹) and a significantly improved high rate performance (a discharge specific capacity of 130.62 mAh g⁻¹ at 10 C), twice that of pristine NCM811. Additionally, cycling stability is also improved for the composite material. This work provides a new possibility of active oxide cathodes for high energy/power Li-ion batteries by electronic conductor LaNiO₃ coating.     

Synthesis and Characterization of Sn/SnO2/C Nano-Composite Structure: High-Performance Negative Electrode for Lithium-Ion Batteries

Tin oxide (SnO₂) and tin-based composites along with carbon have attracted significant interest as negative electrodes for lithium-ion batteries (LIBs). However, tin-based composite electrodes have some critical drawbacks, such as high volume expansion, low capacity at high current density due to low ionic conductivity, and poor cycle stability. Moreover, complex preparation methods and high-cost carbon coating procedures are considered main challenges in the commercialization of tin-based electrodes for LIBs. In this study, we prepared a Sn/SnO₂/C nano-composite structure by employing a low-cost hydrothermal method, where Sn nanoparticles were oxidized in glucose and carboxymethyl cellulose CMC was introduced into the solution. Scanning electron microscope (SEM) and transmission electron microscope revealed the irregular structure of Sn nanoparticles and SnO₂ phases in the conductive carbon matrix. The as-prepared Sn/SnO₂/C nano-composite showed high first-cycle reversible discharge capacity (2248 mAhg⁻¹) at 100 mAg⁻¹ with a first coulombic efficiency of 70%, and also displayed 474.64 mAhg⁻¹ at the relatively high current density of about 500 mAg⁻¹ after 100 cycles. A low-cost Sn/SnO₂/C nano-composite with significant electrochemical performance could be the next generation of high-performance negative electrodes for LIBs.     

Flake (NH4)6Mo7O24/Polydopamine as a High Performance Anode for Lithium Ion Batteries

Ammonium molybdate tetrahydrate ((NH₄)₆Mo₇O₂₄) (AMT) is commonly used as the precursor to synthesize Mo-based oxides or sulfides for lithium ion batteries (LIBs). However, the electrochemical lithium storage ability of AMT itself is unclear so far. In the present work, AMT is directly examined as a promising anode material for Li-ion batteries with good capacity and cycling stability. To further improve the electrochemical performance of AMT, AMT/polydopamine (PDA) composite was simply synthesized via recrystallization and freeze drying methods. Unlike with block shape for AMT, the as-prepared AMT/PDA composite shows flake morphology. The initial discharge capacity of AMT/PDA is reached up to 1471 mAh g⁻¹. It delivers a reversible discharge capacity of 702 mAh g⁻¹ at a current density of 300 mA g⁻¹, and a stable reversible capacity of 383.6 mA h g⁻¹ is retained at a current density of 0.5 A g⁻¹ after 400 cycles. Moreover, the lithium storage mechanism is fully investigated. The results of this work could potentially expand the application of AMT and Mo-based anode for LIBs.     

Enhanced Cyclability of Cr8O21 Cathode for PEO-Based All-Solid-State Lithium-Ion Batteries by Atomic Layer Deposition of Al2O3

Cr₈O₂₁ can be used as the cathode material in all-solid-state batteries with high energy density due to its high reversible specific capacity and high potential plateau. However, the strong oxidation of Cr₈O₂₁ leads to poor compatibility with polymer-based solid electrolytes. Herein, to improve the cycle performance of the battery, Al₂O₃ atomic layer deposition (ALD) coating is applied on Cr₈O₂₁ cathodes to modify the interface between the electrode and the electrolyte. X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscope, and Fourier transform infrared spectroscopy, etc., are used to estimate the morphology of the ALD coating and the interface reaction mechanism. The electrochemical properties of the Cr₈O₂₁ cathodes are investigated. The results show that the uniform and dense Al₂O₃ layer not only prevents the polyethylene oxide from oxidization but also enhances the lithium-ion transport. The 12-ALD-cycle-coated electrode with approximately 4 nm Al₂O₃ layer displays the optimal cycling performance, which delivers a high capacity of 260 mAh g⁻¹ for the 125th cycle at 0.1C with a discharge-specific energy of 630 Wh kg⁻¹.     

Composite Fe3O4-MXene-Carbon Nanotube Electrodes for Supercapacitors Prepared Using the New Colloidal Method

MXenes, such as Ti₃C₂T_x, are promising materials for electrodes of supercapacitors (SCs). Colloidal techniques have potential for the fabrication of advanced Ti₃C₂T_x composites with high areal capacitance (C_S). This paper reports the fabrication of Ti₃C₂T_X-Fe₃O₄-multiwalled carbon nanotube (CNT) electrodes, which show C_S of 5.52 F cm⁻² in the negative potential range in 0.5 M Na₂SO₄ electrolyte. Good capacitive performance is achieved at a mass loading of 35 mg cm⁻² due to the use of Celestine blue (CB) as a co-dispersant for individual materials. The mechanisms of CB adsorption on Ti₃C₂T_X, Fe₃O₄, and CNTs and their electrostatic co-dispersion are discussed. The comparison of the capacitive behavior of Ti₃C₂T_X-Fe₃O₄-CNT electrodes with Ti₃C₂T_X-CNT and Fe₃O₄-CNT electrodes for the same active mass, electrode thickness and CNT content reveals a synergistic effect of the individual capacitive materials, which is observed due to the use of CB. The high C_S of Ti₃C₂T_X-Fe₃O₄-CNT composites makes them promising materials for application in negative electrodes of asymmetric SC devices.     

Recycling spent LiNi1-x-yMnxCoyO2 cathodes to bifunctional NiMnCo catalysts for zinc-air batteries

The skyrocketing production of lithium-ion batteries (LIBs) for electric vehicles portends that tremendous numbers of used LIBs will be generated. However, the recycling of used LIBs is limited by the complicated separation processes of traditional pyrometallurgy and hydrometallurgy methods. Here, we applied a rapid thermal radiation method to convert spent LiNi_1-x-yMn_xCo_yO₂ (NMC) cathodes from used LIBs into highly efficient NiMnCo-based catalysts for zinc-air batteries (ZABs) through acid leaching and radiative heating processes, which avoids sophisticated separation of different metals and can synthesize the catalysts rapidly. The prepared NiMnCo-activated carbon (NiMnCo-AC) catalyst presents a unique core-shell structure, with face-centered cubic Ni in the core and spinel NiMnCoO₄ in the shell, which redistributes the electronic structure of the NiMnCoO₄ shell to decrease the energy barrier for oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) processes and ensures high electrocatalytic activities. The NiMnCo-AC catalyst in ZABs as cathode materials exhibits a high power density of 187.7 mW cm⁻², low voltage gap of 0.72 V at the initial three cycles, and long cycling duration of 200 h at the current density of 10 mA cm⁻². This work provides a promising strategy to recycle spent LIBs to highly efficient catalysts for ZABs.

The worldwide trend of developing electric vehicles largely increases the demand for lithium-ion batteries (LIBs), which causes the price of related metals (e.g., Li, Ni, Co, and Mn) to soar and generates millions of tons of used LIBs (1–4). The large amount of LIBs waste leads to serious environmental pollution (5–7). To alleviate the environmental problems and mitigate the shortage of related metals, it is of critical importance to recycle these metals from spent LIBs (8–11). LiNi_1-x-yMn_xCo_yO₂ (NMC)-type cathodes are largely used in LIBs due to their high energy density and good electrochemical stability; therefore, bountiful Li, Ni, Mn, and Co metals in spent NMC cathodes can be recovered (12–14). Transition metals (e.g., Ni, Mn, and Co) usually exhibit promising bifunctional oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) performance (15–17). As one of the most promising energy storage devices, zinc-air batteries (ZABs) need the ORR/OER in the cathode side, which calls for low-cost bifunctional catalysts as cathode materials (18–20). Thus, converting the NMC scraps into highly efficient NiMnCo-based catalyst cathodes for ZABs can not only alleviate environmental pollution, but also significantly reduce the cost of ZABs.Various strategies have been proposed to recover Ni, Mn, and Co from spent NMC cathodes, among which typical pyrometallurgy and hydrometallurgy methods are commonly used (21–23). Pyrometallurgy smelts the spent cathode materials in a blast furnace at high temperatures to produce transition metal alloys, followed by multistep purification and separation processes (24, 25). Hydrometallurgy dissolves the metals through an acid leaching process and separates the transition metals by subsequent extraction and precipitation steps (26–28). However, both the pyrometallurgy and hydrometallurgy methods involve multistep separation processes of the transition metals, which largely increases the difficulty in recycling the NMC cathode, leading to low recovery efficiency and high recovery cost (29, 30). To avoid the complicated separation processes, methods of directly converting cathode scraps into highly efficient catalysts have been pursued (31, 32). It is verified that the layered lithium transition metal oxides (typical cathode materials in LIBs) exhibit improved catalytic activity of OER after the delithiation process (33–36). In addition, with the modification of Ni, the spent LiFePO₄ cathode presents high OER performance because of the in situ evolution of Ni-LiFePO₄ active materials (16). Even though the spent cathode materials can be used as catalysts after modification, the large particle size limits their applications in ORR, and they are rarely studied in ZABs as cathode materials. Therefore, it is important to directly convert NMC cathodes into nanosized catalysts to improve the bifunctional ORR/OER catalytic activities, which makes it possible to use them as cathode materials in ZABs.Herein, we report a rapid thermal radiation method to synthesize NiMnCo-activated carbon (NiMnCo-AC) catalysts from spent NMC cathodes efficiently. The NiMnCo nanoparticles are determined to be a core-shell structure with face-centered cubic (fcc) Ni in the core and spinel NiMnCoO₄ in the shell, which delivers competitive ORR/OER performance in alkaline solutions. Density functional theory (DFT) calculations elucidate that the Ni core induces the redistribution of the electronic structure of the NiMnCoO₄ shell, and the NiMnCoO₄ shell provides efficient active sites for the ORR/OER processes; therefore, the synergistic effect between the Ni core and the NiMnCoO₄ lowers the energy barrier of the rate-determining step. Based on the unique core-shell structure of the NiMnCo-AC cathode, the ZAB exhibits a high discharge capacity of 779 mAh g⁻¹ at the high current density of 50 mA cm⁻¹, the low voltage gap of 0.72 V at the initial three cycles, superior cycling stability for 200 h at the current density of 10 mA cm⁻², and excellent flexibility to power the light-emitting diode (LED) at a bending state.     

Resonant frequency does not predict high-frequency chest compression settings that maximize airflow or volume

High‐frequency chest compression (HFCC) is a therapy for cystic fibrosis (CF). We hypothesized that the resonant frequency (f_res), as measured by impulse oscillometry, could be used to determine what HFCC vest settings produce maximal airflow or volume in pediatric CF patients. In 45 subjects, we studied: f_res, HFCC vest frequencies that subjects used (f_used), and the HFCC vest frequencies that generated the greatest volume (f_vol) and airflow (f_flow) changes as measured by pneumotachometer. Median f_used for 32 subjects was 14 Hz (range, 6–30). The rank order of the three most common f_used was 15 Hz (28%) and 12 Hz (21%); three frequencies tied for third: 10, 11, and 14 Hz (5% each). Median f_res for 43 subjects was 20.30 Hz (range, 7.85–33.65). Nineteen subjects underwent vest‐tuning to determine f_vol and f_flow. Median f_vol was 8 Hz (range, 6–30). The rank order of the three most common f_vol was: 8 Hz (42%), 6 Hz (32%), and 10 Hz (21%). Median f_flow was 26 Hz (range, 8–30). The rank order of the three most common f_flow was: 30 Hz (26%) and 28 Hz (21%); three frequencies tied for third: 8, 14, and 18 Hz (11% each). There was no correlation between f_used and f_flow (r² = ?0.12) or f_vol (r² = 0.031). There was no correlation between f_res and f_flow (r² = 0.19) or f_vol (r² = 0.023). Multivariable analysis showed no independent variables were predictive of f_flow or f_vol. Vest‐tuning may be required to optimize clinical utility of HFCC. Multiple HFCC frequencies may need to be used to incorporate f_flow and f_vol. Pediatr. Pulmonol. 2011; 46:604–609. © 2011 Wiley‐Liss, Inc.     

Self-Supported Fibrous Sn/SnO2@C Nanocomposite as Superior Anode Material for Lithium-Ion Batteries

Low-cost and simple methods are constantly chased in order to produce less expensive lithium-ion batteries (LIBs) while possibly increasing the energy and power density as well as the volumetric capacity in order to boost a rapid decarbonization of the transport sector. Li alloys and tin-carbon composites are promising candidates as anode materials for LIBs both in terms of capacity and cycle life. In the present paper, electrospinning was employed in the preparation of Sn/SnO_x@C composites, where tin and tin oxides were homogeneously dispersed in a carbonaceous matrix of carbon nanofibers. The resulting self-standing and light electrode showed a greatly enhanced performance compared to a conventional electrode based on the same starting materials that are simply mixed to obtain a slurry then deposited on a Cu foil. Fast kinetics were achieved with more than 90% of the reaction that resulted being surface-controlled, and stable capacities of about 300 mAh/g over 500 cycles were obtained at a current density of 0.5 A/g.     

Confined Polysulfides in N-Doped 3D-CNTs Network for High Performance Lithium-Sulfur Batteries

Improving the utilization efficiency of active materials and suppressing the dissolution of lithium polysulfides into the electrolyte are very critical for development of high-performance lithium-sulfur batteries. Herein, a novel strategy is proposed to construct a three-dimensional (3D) N-doped carbon nanotubes (CNTs) networks to support lithium polysulfides (3D-NCNT-Li₂S₆) as a binder-free cathode for high-performance lithium-sulfur batteries. The 3D N-doped CNTs networks not only provide a conductive porous 3D architecture for facilitating fast ion and electron transport but also create void spaces and porous channels for accommodating active sulfur. In addition, lithium polysulfides can be effectively confined among the networks through the chemical bond between Li and N. Owing to the synergetic effect of the physical and chemical confinement for the polysulfides dissolution, the 3D-NCNT-Li₂S₆ cathodes exhibit enhanced charge capacity and cyclic stability with lower polarization and faster redox reaction kinetics. With an initial discharge capacity of 924.8 mAh g⁻¹ at 1 C, the discharge capacity can still maintain 525.1 mAh g⁻¹ after 200 cycles, which is better than that of its counterparts.     

Flexible Quasi-Solid-State Composite Electrolyte of Poly (Propylene Glycol)-co-Pentaerythritol Triacry-Late/Li1.5Al0.5Ge1.5(PO4)3 for High-Performance Lithium-Sulfur Battery

With a higher theoretical specific capacity (1675 mAh g⁻¹) and energy density (2600 Wh kg⁻¹), the lithium-sulfur (Li-S) battery is considered as a promising candidate for a next-generation energy storage device. However, the shuttle effect of polysulfides as well as the large interfacial impedance between brittle solid electrolyte and electrodes lead to the capacity of the Li-S battery decaying rapidly, which limits the practical commercial applications of the Li-S battery. Herein, we reported a facile in situ ultraviolet (UV) curing method to prepare a flexible quasi-solid-state composite electrolyte (QSSCE) of poly(propylene glycol)-co-pentaerythritol triacrylate/Li_1.5Al_0.5Ge_1.5(PO₄)₃ (PPG-co-PETA/LAGP). By combining the high Li-ion conductivity and mechanical strength of inorganic NASICON-structure LAGP and good flexibility of the crosslinked PPG-co-PETA with nanopore structure, the flexible QSSCE with 66.85 wt% LAGP exhibited high Li-ion conductivity of 5.95 × 10⁻³ S cm⁻¹ at 25 °C, Li-ion transference number of 0.83 and wide electrochemical window of ~5.0 V (vs. Li/Li⁺). In addition, the application of QSSCE in the Li-S battery could suppress the shuttle effect of polysulfides effectively, thus the Li-S battery possessed the excellent electrochemical cyclic performance, showing the first-cycle discharge-specific capacity of 1508.1 mAh g⁻¹, the capacity retention of 73.6% after 200 cycles with 0.25 C at 25 °C and good rate performance.     

Scalable Synthesis and Electrochemical Properties of Porous Si-CoSi2-C Composites as an Anode for Li-ion Batteries

Si-based anodes for Li-ion batteries (LIBs) are considered to be an attractive alternative to graphite due to their higher capacity, but they have low electrical conductivity and degrade mechanically during cycling. In the current study, we report on a mass-producible porous Si-CoSi₂-C composite as a high-capacity anode material for LIBs. The composite was synthesized with two-step milling followed by a simple chemical etching process. The material conversion and porous structure were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy. The electrochemical test results demonstrated that the Si-CoSi₂-C composite electrode exhibits greatly improved cycle and rate performance compared with conventional Si-C composite electrodes. These results can be ascribed to the role of CoSi₂ and inside pores. The CoSi₂ synthesized in situ during high-energy mechanical milling can be well attached to the Si; its conductive phase can increase electrical connection with the carbon matrix and the Cu current collectors; and it can accommodate Si volume changes during cycling. The proposed synthesis strategy can provide a facile and cost-effective method to produce Si-based materials for commercial LIB anodes.     

Boosting Lithium Storage of a Metal-Organic Framework via Zinc Doping

Lithium-ion batteries (LIBs) as a predominant power source are widely used in large-scale energy storage fields. For the next-generation energy storage LIBs, it is primary to seek the high capacity and long lifespan electrode materials. Nickel and purified terephthalic acid-based MOF (Ni-PTA) with a series amounts of zinc dopant (0, 20, 50%) are successfully synthesized in this work and evaluated as anode materials for lithium-ion batteries. Among them, the 20% atom fraction Zn-doped Ni-PTA (Zn_0.2-Ni-PTA) exhibits a high specific capacity of 921.4 mA h g⁻¹ and 739.6 mA h g⁻¹ at different current densities of 100 and 500 mA g⁻¹ after 100 cycles. The optimized electrochemical performance of Zn_0.2-Ni-PTA can be attributed to its low charge transfer resistance and high lithium-ion diffusion rate resulting from expanded interplanar spacing after moderate Zn doping. Moreover, a full cell is fabricated based on the LiFePO₄ cathode and as-prepared MOF. The Zn_0.2-Ni-PTA shows a reversible specific capacity of 97.9 mA h g⁻¹ with 86.1% capacity retention (0.5 C) after 100 cycles, demonstrating the superior electrochemical performance of Zn_0.2-Ni-PTA anode as a promising candidate for practical lithium-ion batteries.     

Enhanced Electrochemical Performance Promoted by Tin in Silica Anode Materials for Stable and High-Capacity Lithium-Ion Batteries

Although the silicon oxide (SiO₂) as an anode material shows potential and promise for lithium-ion batteries (LIBs), owing to its high capacity, low cost, abundance, and safety, severe capacity decay and sluggish charge transfer during the discharge–charge process has caused a serious challenge for available applications. Herein, a novel 3D porous silicon oxide@Pourous Carbon@Tin (SiO₂@Pc@Sn) composite anode material was firstly designed and synthesized by freeze-drying and thermal-melting self-assembly, in which SiO₂ microparticles were encapsulated in the porous carbon as well as Sn nanoballs being uniformly dispersed in the SiO₂@Pc-like sesame seeds, effectively constructing a robust and conductive 3D porous Jujube cake-like architecture that is beneficial for fast ion transfer and high structural stability. Such a SiO₂@Pc@Sn micro-nano hierarchical structure as a LIBs anode exhibits a large reversible specific capacity ~520 mAh·g⁻¹, initial coulombic efficiency (ICE) ~52%, outstanding rate capability, and excellent cycling stability over 100 cycles. Furthermore, the phase evolution and underlying electrochemical mechanism during the charge–discharge process were further uncovered by cyclic voltammetry (CV) investigation.     

High Electrochemical Performance Silicon Thin-Film Free-Standing Electrodes Based on Buckypaper for Flexible Lithium-Ion Batteries

Recently, applications for lithium-ion batteries (LIBs) have expanded to include electric vehicles and electric energy storage systems, extending beyond power sources for portable electronic devices. The power sources of these flexible electronic devices require the creation of thin, light, and flexible power supply devices such as flexile electrolytes/insulators, electrode materials, current collectors, and batteries that play an important role in packaging. Demand will require the progress of modern electrode materials with high capacity, rate capability, cycle stability, electrical conductivity, and mechanical flexibility for the time to come. The integration of high electrical conductivity and flexible buckypaper (oxidized Multi-walled carbon nanotubes (MWCNTs) film) and high theoretical capacity silicon materials are effective for obtaining superior high-energy-density and flexible electrode materials. Therefore, this study focuses on improving the high-capacity, capability-cycling stability of the thin-film Si buckypaper free-standing electrodes for lightweight and flexible energy-supply devices. First, buckypaper (oxidized MWCNTs) was prepared by assembling a free stand-alone electrode, and electrical conductivity tests confirmed that the buckypaper has sufficient electrical conductivity (10⁻⁴(S m⁻¹) in LIBs) to operate simultaneously with a current collector. Subsequently, silicon was deposited on the buckypaper via magnetron sputtering. Next, the thin-film Si buckypaper freestanding electrodes were heat-treated at 600 °C in a vacuum, which improved their electrochemical performance significantly. Electrochemical results demonstrated that the electrode capacity can be increased by 27/26 and 95/93 μAh in unheated and heated buckypaper current collectors, respectively. The measured discharge/charge capacities of the USi_HBP electrode were 108/106 μAh after 100 cycles, corresponding to a Coulombic efficiency of 98.1%, whereas the HSi_HBP electrode indicated a discharge/charge capacity of 193/192 μAh at the 100th cycle, corresponding to a capacity retention of 99.5%. In particular, the HSi_HBP electrode can decrease the capacity by less than 1.5% compared with the value of the first cycle after 100 cycles, demonstrating excellent electrochemical stability.     

High Capacity Nanocomposite Layers Based on Nanoparticles of Carbon Materials and Ruthenium Dioxide for Potassium Sensitive Electrode

This work presents the new concept of designing ion-selective electrodes based on the use of new composite materials consisting of carbon nanomaterials and ruthenium dioxide. Using two different materials varying in microstructure and properties, we could obtain one material for the mediation layer that adopted features coming of both components. Ruthenium dioxide characterized by high electrical capacity and mixed electronic-ionic transduction and nano-metric carbon materials were reportedly proved to improve the properties of ion-selective electrodes. Initially, only the materials and then the final electrodes were tested in the scope of the presented work, using scanning and transmission electron microscope, contact angle microscope, and various electrochemical techniques, including electrochemical impedance spectroscopy and chronopotentiometry. The obtained results confirmed beneficial influence of the designed nanocomposites on the ion-selective electrodes’ properties. Nanosized structure, high capacity (characterized by the electrical capacitance value from approximately 5.5 mF for GR + RuO₂ and CB + RuO₂, up to 14 mF for NT + RuO₂) and low hydrophilicity (represented by the contact angle from 60° for GR+RuO₂, 80° for CB+RuO₂, and up to 100° for NT + RuO₂) of the mediation layer materials, allowed us to obtain water layer-free potassium-selective electrodes, characterized by rapid and stable potentiometric response in a wide range of concentrations-from 10⁻¹ to 10⁻⁶ M K⁺.