Browse Topic: Sodium
Additive manufacturing (AM) processes facilitate the production of components with high geometrical complexity, presenting substantial opportunities for innovation in demanding sectors such as aerospace and biomedical engineering. A significant challenge impeding their broader application is the characteristic surface roughness of as-fabricated parts, which results from the layer-wise construction and the presence of partially melted powder particles. While electrochemical polishing (EP) represents a viable post-processing technique for achieving a smooth surface finish, a comprehensive understanding of how the non-equilibrium microstructures characteristic of AM materials interact with the EP process remains incomplete. This investigation centers on the electrochemical polishing behavior of Ti-6Al-4V alloy fabricated by direct energy deposition (DED), utilizing a sodium chloride-ethylene glycol electrolyte. The findings reveal that the material's distinct engenders anisotropic anodic dissolution. This behavior is attributed to the differential electrochemical potentials among the constituent phases and their crystallographic orientations, which consequently narrows the operational process window for effective, uniform polishing. This preferential dissolution of certain phases results in the formation of a subtle, micro-scale topographical variation that mirrors the orientation of the original columnar grain structure. Notwithstanding this microstructural influence, the EP treatment proved highly successful in refining the surface finish, substantially decreasing the average surface roughness from 0.350 μm to 0.042 μm. Concurrently, the treatment led to a significant enhancement in the alloy's corrosion resistance, attributed to an oxide layer. These findings underscore the critical necessity of accounting for microstructural characteristics when developing optimized electrochemical polishing protocols for additively manufactured components.
Sodium-ion batteries (SIBs) are becoming a strong candidate for large-scale energy storage applications due to their cost-effectiveness and abundant sodium resource reserves. Ether solvents have advantages such as excellent low-temperature performance and good reduction stability. However, poor oxidation stability limits the use of ether-based electrolytes, which need to be addressed urgently. In this study, 1 M sodium tetrafluoroborate (NaBF4) and 0.05 M sodium difluoro(oxalato)borate (NaDFOB) were added in tetraethylene glycol dimethyl ether (G4), which is named “BDG4”. BDG4 electrolyte can promote the formation of cathode electrolyte interface (CEI) layers containing NaF and B─O/B─Na inorganic components on the surface of the cathode. The dense CEI layers can prevent the solvent from undergoing oxidation reactions. Therefore, thanks to the lower highest occupied molecular orbital (HOMO) energy level of G4 and its close coordination structure with Na+, the electrolyte has a high-voltage stability exceeding 4.5 V versus Na+/Na. Therefore, BDG4 electrolyte can be stably cycled on Na3(VO)2(PO4)2F (NVOPF) and NaNi1/3Fe1/3Mn1/3O2 (NFM) cathode for over 250 cycles at room temperature, exhibiting a high Coulombic Efficiency (CE) exceeding 99.8%. Furthermore, BDG4 demonstrated excellent rate performance of NFM cathode, maintaining 75% capacity retention even at 4 C. Due to the stable solid electrolyte interface (SEI) layers formed by the mixture of inorganic and organic components, BDG4 electrolyte can also cycle stably on the Hard Carbon (HC) anode. Therefore, the commercial NFM||HC pouch full cell can cycle stably with 88.3% capacity retention after 80 cycles. This work reveals the role of NaDFOB and provides a feasible approach for the design of high-voltage ether electrolytes of SIBs.
All-solid-state batteries are safe, powerful ways to power EVs and electronics and store electricity from the energy grid, but the lithium used to build them is rare, expensive, and can be environmentally devastating to extract. Sodium is an inexpensive, plentiful, less-destructive alternative, but the all-solid-state batteries they create currently don’t work as well at room temperature.
Anode-free sodium metal batteries (AFSMBs) with initial zero sodium anodes are promising energy-storage devices to achieve high energy density and low cost. The morphology and reversibility of sodium controls the cycling lifespan of the AFSMBs, which is directly affected by the separator. Here, we compared the sodium deposition and corresponding electrochemical behaviors under the influence of three commercial separators, which were Celgard 2500, Al2O3-coated PP separator and glass fiber (denoting as 2500, C-PP and GF). Firstly, the reversibility of sodium plating/stripping was tested using half-cells, where coulombic efficiencies were stable at ~99.89% for C-PP and GF compare to 99.65% for 2500, indicating more dead sodium were formed for 2500. Then, the morphologies of deposited sodium were compared using optical microscopy. Compared to inhomogeneous sodium growth under 2500, C-PP obtained more flatter sodium layer with less height difference, attributing to the high mechanical strength of Al2O3 layer. Differently, we discovered that sodium was grown into pores in GF to form sodium particles with large active surface, which contacts with sufficient electrolytes and could be reversibly stripped. The reversibility of the sodium in GF were further verified using in situ X-ray diffraction tests. Accordingly, cycling performance of AFSMBs were improved using C-PP and GF, where capacity retention after 120 cycles were 56.9%, 61.6% and 69.2% for 2500, C-PP and GF, respectively. Moreover, the AFSMB using 2 mAh cm-2 Na[Ni1/3Fe1/3Mn1/3]O2 as cathode with GF exhibiting excellent capacity of 117.61 mAh g-1 under high current density of 1 C. Subsequently, in situ EIS tests after/during charging/discharging process were further conducted to illustrate the enhancement of rate and cycling performance. This work demonstrates the effect of separators on the sodium deposition for higher irreversibility and stability, which could also offer insights for developing advanced separators to achieve high performance AFSMBs.
University of Chicago Pritzker Molecular Engineering Professor Y. Shirley Meng’s Laboratory for Energy Storage and Conversion (LESC) has created the world’s first anode-free sodium solid-state battery.
Sodium (Na), which is over 500 times more abundant than lithium (Li), has recently garnered significant attention for its potential in sodium-ion battery technologies. However, existing sodium-ion batteries face fundamental limitations, including lower power output, constrained storage properties, and longer charging times, necessitating the development of next-generation energy storage materials.
A unique wristwatch contains multiple modules, including a sensor array, a microfluidic chip, signal processing, and a data display system to monitor chemicals in human sweat. It can continuously and accurately monitor the levels of potassium (K+), sodium (Na+), and calcium (Ca2+) ions.
Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have invented and patented a new cathode material that replaces lithium ions with sodium and would be significantly cheaper. The cathode is one of the main parts of any battery. It is the site of the chemical reaction that creates the flow of electricity that propels a vehicle.
In the quest for sustainable materials for automotive interior trim, jute fiber is gaining traction due to its characteristics, which align with other renowned natural fibers. This study aimed to assess the efficacy of sodium bicarbonate as a treatment for jute fibers in comparison to conventional alkaline treatments. Both treated and untreated fibers were examined. Results showed that alkali-processed fibers demonstrated enhanced crystallization, thermal resistance, and surface quality relative to untreated ones. Specifically, alkali-treated jute fibers exhibited a degradation onset at 261.23°C, while those treated with sodium bicarbonate began degrading at 246.32°C. Untreated fibers had a degradation onset at 239.25°C. Although both treatments improved the thermal stability of the fiber, sodium bicarbonate processing, while beneficial, was slightly less effective than the traditional alkaline method. Overall, the research underscores the potential of sodium bicarbonate as an alternative treatment for fibrous materials, even if its efficacy is somewhat lesser than traditional methods. The findings offer insights into optimizing jute fiber for automotive interior trim applications.
A new sensor — so cheap and simple to produce that it can be hand-drawn with a pencil onto paper treated with sodium chloride — could clear the way for wearable, self-powered health monitors for use not only in “smart diapers” but also to predict major health concerns like cardiac arrest and pneumonia.
A new sensor could help workers in daycares, hospitals, and other settings provide more immediate care to their charges. The new sensor — so cheap and simple to produce that it can be hand drawn with a pencil onto paper treated with sodium chloride — could clear the way for wearable, self-powered health monitors for use not only in “smart diapers” but also to predict major health concerns like cardiac arrest and pneumonia.
A new battery design could help ease integration of renewable energy into the nation’s electrical grid at lower cost, using Earth-abundant metals, according to a study just published in Energy Storage Materials. A research team, led by the Department of Energy’s Pacific Northwest National Laboratory, demonstrated that the new design for a grid energy storage battery built with the low-cost metals sodium and aluminum provides a pathway toward a safer and more scalable stationary energy storage system.
Engineers at the University of California San Diego have developed a thin, flexible, stretchy sweat sensor that can show the level of glucose, lactate, sodium, or pH of your sweat — at the press of a finger. It is the first standalone wearable device that allows the sensor to operate independently — sans any wired or wireless connection to external devices — to directly visualize the measurement’s results.
Cheap and abundant, sodium is a prime promising candidate for new battery technology. But limited performance of sodium-ion batteries has hindered their large-scale applications. Now, a research team from the Department of Energy’s Pacific Northwest National Laboratory has developed a sodium-ion battery with greatly extended longevity in laboratory tests.
This specification establishes testing methods for testing chemical composition in nickel- and cobalt-based alloys.
Currently the preferred technology to power electric vehicles, lithium-ion (Li-ion) batteries, has become too expensive for long-duration grid-scale energy storage systems — not to mention that lithium itself is becoming more and more elusive.
The challenges of energy storage — which require the capacity to bank an intermittent and seasonally variable supply of solar energy — have kept the technology from being economically competitive. Researchers have used low-cost materials to create rechargeable batteries that will make energy storage more affordable. These materials could also provide a safer and more environmentally friendly alternative to lithium-ion batteries that currently dominate the market but are slow to charge and have a knack for catching fire.
Biodiesel production from Cucurbita pepo L. was explored in the present investigation. Bio-oil extraction from pumpkin seed was achieved using Soxhlet extraction method. Optimization of input process parameters for achieving the maximum pumpkin seed biodiesel (PkSBD) by a single-stage transesterification process using sodium hydroxide (NaOH) and methanol has been studied. A rotatable central composite design (RCCD) with 20 experimental trial runs was designed using Response Surface Methodology (RSM) to understand the interdependency between alcohol-to-bio-oil ratio, catalyst loading, and reaction duration. The developed model predicted maximum PkSBD at 0.84 v/v methanol-to-bio-oil ratio, 3.48 g/g catalyst loading, and 91.7 min reaction duration as 98.87%, and this was also validated experimentally. The physicochemical characterization was identified by Gas Chromatography-Mass Spectrometry (GC/MS) analysis, which revealed the presence of palmitic and linolenic acid in prominent proportions, and the properties fulfilled the requirement of global standards. Thus, producing biodiesel from pumpkin seed oil was found to be a viable option.
New synthesized materials open the way to govern the density of helicity, axial charge, and its flow, axial current. Air Force Research Laboratory, Arlington, Virginia The major factor determining transport properties of solids is the number of electron states in a vicinity of Fermi level. In equilibrium, no macroscopic flow of electrons exists and, therefore, in order to create such flow, electrons must be excited over their equilibrium distribution. However, electrons with energies well below the Fermi level (compared to the characteristic energy scale kBT, where kB is the Boltzmann constant and T is the temperature), cannot acquire small excitation energy. Indeed, in this case, they would have energy corresponding to already occupied states, which is prohibited by the Pauli principle. In turn, well above the Fermi level, where excitation of electrons is not constrained by the Pauli principle, the electron states are not populated, thus making their contribution to the response negligible. An elementary classification of materials as conductors and insulators is, therefore, based on the relation between the Fermi level and the energy bands characterizing electron states in the solid. In metals, such as copper or silver, the Fermi level is inside the band and, therefore, metals have high electric and thermal conductivities. In insulators, for instance, silicon dioxide (SiO2) or crystal sodium chloride (NaCl), the Fermi level is inside the wide, conventionally more than 4 eV, bandgap separating valence and conduction (below and above the Fermi level, respectively) bands, for example, Δ ≈ 8.9 eV in SiO2 and Δ ≈ 8.5 eV in NaCl.
Several elements affect the structure of eutectic silicon in hypoeutectic aluminum alloys [1, 2, 3, 4]. Among them, calcium has been investigated to a lesser extent compared to the typically used sodium and strontium. In order to enhance the thermal fatigue strength of a small engine, the morphology of eutectic silicon in hypoeutectic aluminum-silicon alloys is controlled by the addition of calcium. In addition, the castability and mechanical properties are investigated. Hence, samples containing different amounts of calcium are prepared at different cooling rates during solidification. The results revealed that, with the increase in the calcium amount and the cooling rate, eutectic silicon exhibits a fine morphology in cross-sectional images. Particularly, with the addition of at least 62 mass ppm of calcium in a specific range of cooling rates, refined eutectic silicon is obtained. In order to clarify additional effects of the added calcium, the amount of dissolved gas, fluidity, and porosity defects are evaluated. The amount of dissolved gas and the fluidity do not change in the range of the investigated calcium amounts. However, the sizes of each of the shrinkage porosities decrease and the region where porosities generated is spread, with spread-out regions. The sample strength with refined eutectic silicon is evaluated by tension and thermal fatigue tests. Refined samples exhibit greater elongation and thermal fatigue strength compared with those of eutectic silicon with a coarse morphology. The addition of calcium leads to the effective enhancement of the mechanical properties of hypoeutectic aluminum-silicon alloys.
As a consequence of the ongoing evolution of engines, where performance is continuously improving and the use of alternative fuels is being adopted by many engine manufacturers, thermal working conditions of the exhaust valves are increasingly critical. In order to better resist the higher temperature levels of the exhaust gases, current development ranges from improvement of the cooling concept for the overall system, new materials for valve set components up to the upgrade of the exhaust manifold material. Change in the design of several valvetrain components due to the increased thermal loads is a logical consequence of this technical evolution process. Hollow exhaust valves filled with Sodium (Na) are a known technology that is widely used in passenger car engines to improve thermal behavior and to avoid the need to change to expensive materials (Ni-base alloys). Nevertheless, shaker-cooling effect of Na for engine speeds below 3.000 [rpm] has been questioned in the past and this technology has not been fully explored in heavy duty (HD) applications [1]. In order to investigate the thermal efficiency or effectiveness and to confirm Na-filled valves as a potential technical solution for thermal issues in HD engines, back-to-back analyses (FEA) and tests (temperature measurements and endurance) were performed, mainly focused on heavy duty spark ignition (SI) engines (gas fueled) and on severe applications of diesel engines.
Laser and electro-optic technologies are under development to remotely measure sodium (Na) by adapting existing LiDAR technology with spaceflight heritage. The developed instrumentation will serve as the core for planning a heliophysics mission targeted to study the composition and dynamics of Earth's mesosphere based on a spaceborne LiDAR that will measure the mesospheric Na layer.
The metal layers at mesospheric altitudes are excellent tracers of neutral atmosphere dynamics, and have been used since the 1960s to study the chemistry and dynamics of the mesosphere. Ablation from meteors is believed to be the chief source of metals such as Na, Mg, K, Fe, and Ca in the middle atmosphere. Due to its relative abundance, large backscatter cross-section, and visible atomic transition, sodium (Na) has been used extensively for lidar studies of the mesosphere.
A satellite-borne sodium lidar will provide key measurements that elucidate the complex relation between the chemistry and dynamics of the Earth’s mesosphere, and thus provide a thorough understanding of the composition and dynamics of this region. The inclusion of a well-characterized mesosphere in global models is essential for weather and climate prediction in the lower atmosphere. It also will help to elucidate the complex vertical coupling processes through which atmospheric weather affects space weather. Furthermore, once the technique is developed, it can be used to study the composition of other planetary atmospheres, which is identified as a key point in the recent Planetary Decadal Survey.
Improvements in the efficiency of internal combustion engines and the development of renewable liquid fuels have both been deployed to reduce exhaust emissions of CO2. An additional approach is to scrub CO2 from the combustion gases, and one potential means by which this might be achieved is the reaction of combustions gases with sodium borohydride to form sodium carbonate. This paper presents experimental studies carried out on a modern direct injection diesel engine supplied with a solution of dissolved sodium borohydride so as to investigate the effects of sodium borohydride on combustion and emissions. Sodium borohydride was dissolved in the ether diglyme at concentrations of 0.1 and 2 % (wt/wt), and tested alongside pure diglyme and a reference fossil diesel. The sodium borohydride solutions and pure diglyme were supplied to the fuel injector under an inert atmosphere and tested at a constant injection timing and constant engine indicated mean effective pressure (IMEP). The 0.1 % sodium borohydride diglyme solution and pure diglyme exhibited durations of ignition delay shorter than that of the reference fossil diesel, while testing of the 2 % sodium borohydride solution resulted in failure of the fuel injector. Addition of the dissolved sodium borohydride was found to increase the duration of fuel injection required to maintain a constant engine IMEP by as much as 50 %, with a concurrent increase in the duration of combustion also observed. Levels of exhaust unburnt hydrocarbons did not increase with the addition of sodium borohydride suggesting a detrimental effect of the sodium borohydride on the injector efficiency. Measurement of exhaust emissions of particulate mass and scanning electron microscopy (SEM) of exhaust soot samples both indicated greatly increased soot emissions with the addition of sodium borohydride. Chemical analysis of the exhaust soot samples found no evidence of sodium carbonate or bicarbonate compounds, possibly suggesting deposition of sodium compounds inside the engine combustion chamber.
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