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Hu, Anming

Publications and source records attributed to Hu, Anming.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

High performance aluminum-air flow batteries through double-face architecture and laser-modified and friction-stir processed 3D anode

Aluminum-air batteries (AAB) are regarded as one of the most promising beyond-lithium high-energy-density storage candidates. Here, this paper introduces a three-dimensional (3D) Al 7075 anode enabled by femtosecond laser and friction-stir process which, along with a special double-face anode architecture provides world-class performance. Electrochemical characterizations prove that the corrosion resistance of the modified 3D Al 7075 FSP anode was enhanced, and electrochemically active surface area (ECSA) was increased compared with that of normal Al 7075 anode. Friction-stir processing reduced the mean grain size from 30 μm to 3 μm. The discharge performance of 3D Al 7075 FSP anode is shown to be quite stable, and the average values of energy density are significantly increased from 2256 mWh g –1 to 2941 mWh g –1 at 100 mA cm –2 . In a double-face flowing Al-air battery system, the 3D Al 7075 FSP anode exhibited significantly better electrocatalytic performance (discharge voltage of 0.76 V at 400 mA cm –2 , and power density of 337.8 mW cm –2 ) than that of a commercial Al 7075 anode.

25 ENERGY STORAGE↗
DOE OSTI2023

Femtosecond Laser-Induced Nano-Joining of Volatile Tellurium Nanotube Memristor

Nanowire/nanotube memristor devices provide great potential for random-access high-density resistance storage. However, fabricating high-quality and stable memristors is still challenging. This paper reports multileveled resistance states of tellurium (Te) nanotube based on the clean-room free femtosecond laser nano-joining method. The temperature for the entire fabrication process was maintained below 190 °C. A femtosecond laser joining technique was used to form nanowire memristor units with enhanced properties. Femtosecond (fs) laser-irradiated silver-tellurium nanotube-silver structures resulted in plasmonic-enhanced optical joining with minimal local thermal effects. This produced a junction between the Te nanotube and the silver film substrate with enhanced electrical contacts. Noticeable changes in memristor behavior were observed after fs laser irradiation. Capacitor-coupled multilevel memristor behavior was observed. Compared to previous metal oxide nanowire-based memristors, the reported Te nanotube memristor system displayed a nearly two-order stronger current response. The research displays that the multileveled resistance state is rewritable with a negative bias.

42 ENGINEERING↗
DOE OSTI2022

Pulse Strengthened and Laser Edge Sealed Vacuum Insulation Glazing

A scalable, low-cost processing strategy for glass strengthening and sealing is proposed to improve the thermal performance of insulating glass units and develop innovative window technologies. In this project, a combination of large area photonic processing, additive manufacturing, and laser encapsulation techniques is reported to realize a vacuum glazing technology to meet the cost, performance, reliability, and throughput demands. A modeling framework for evaluating the mechanical and thermal response was established to verify the structural deformation and thermal conductance. Micro-size glass frits in printing ink and a continuous-wave laser curing were employed to allow the formation of a hermetic bonding layer and led to improvement of glass edge sealing. Various sealing parameters, including laser traveling speed, spot diameter, and laser power were optimized. The water seepage and mechanical strength of the resulting glass-to-glass bonding were examined as well. These results showcase the development of a practical vacuum insulating glazing with several unique features through a combination of photonic processing, laser encapsulation, and additive manufacturing.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Laser strengthening of additive manufactured edge seal for vacuum insulated glazing with micro-size glass frit

Sealing of glass edge is a key step in developing cost-effective and durable vacuum insulated glazing for the drive towards net-zero energy buildings. In this study, to achieve a high-strength sealing with scalable and low-cost processing, we investigated a novel sealing method based on additive manufacturing and laser process and reported quantitative analysis of the laser assisted method sealing strength and the requirement of vacuum insulation glazing. Micro-size glass frits in printing ink and a continuous-wave laser curing were employed to allow the formation of a hermetic bonding layer with low thermal budget. Controlling various sealing parameters including laser traveling speed, spot diameter, and laser power, the water seepage and mechanical strength of the resulting glass-to-glass bonding were examined. Through the response surface methodology, we identified the optimized sealing condition where the bonding strength reached 5.68 MPa. A comparation of the bonding strength between thermal sealing method and laser-assisted method has been analyzed as well.

42 ENGINEERING↗
DOE OSTI2019

Concentration dependence of hydrogen diffusion in α-iron from atomistic perspectives

Evaluation of hydrogen diffusion in structural materials is essential to predict the leakage and embrittlement of hydrogen storage applications. Here, we investigate the atomic-scale diffusion of interstitial hydrogen (H) in α-iron (Fe) over a temperature range from 350 to 900 K with different H concentrations (0.01–5%), employing classical molecular dynamics (MD) simulations. The self-diffusivity of H atoms increases with increasing temperature and decreasing concentration. With low concentrations, the calculated diffusion properties agree well with prior experiments. However, with a higher concentration (≥1%), the H diffusivity at low temperatures deviates from a high-temperature Arrhenius behavior. Through the energetic and structural analysis, we suggest that this deviation is attributed to a reduced mobility due to increased energy barrier by other H interstitials. This work contributes to the effective design of H storage applications by identifying temperature and concentration effects on permeability and addressing possible microstructural transformation.

08 HYDROGEN↗
DOE OSTI2019

All-solid-state supercapacitors from natural lignin-based composite film by laser direct writing

Lignin as a renewable natural resource has been the aim of numerical interest in applications ranging from pitch to porous carbon material. In this work, a facile method is reported to transform lignin into porous conductive carbon structures and interdigitated circuits for supercapacitor devices using femtosecond laser direct writing. Comparative studies revealed that the laser irradiation induced tetrahedral amorphous carbon while only graphitic carbon was obtained through pyrolysis. At the same time, the composite membrane was easily prepared to further optimize the capacities by mixing functional materials (MoS 2 ) into the lignin/polyacrylonitrile (PAN) composite polymers. A MoS2 decorated porous carbon network material could be fabricated through focused femtosecond pulsed laser irradiation of the corresponding composite membranes. The microstructure and spectroscopic features of these laser induced hybrid carbon materials have been deeply investigated. The supercapacitor based on lignin/PAN has high areal specific capacitances of 6.7 mF cm –2 (0.9 F cm –3 ) at 10 mV s –1 . Moreover, doped microsupercapacitors with MoS2 demonstrated enhanced areal capacitances up to 16 mF cm –2 (2.2 F cm –3 ) and at 10 mV s –1 , respectively. The relatively high areal capacitances indicate that the introduced method is potential for innovative manufacturing energy storage devices based on natural lignin.

36 MATERIALS SCIENCE↗
NASA NTRS2019

Fabrication and Performance of NiCuCoFeMn High Entropy Alloy Nanopastes for Brazing Inconel 718

Overview: High entropy alloys (HEAs) are a class of metallic alloys consisting of 5 plus elemental components and have four core effects - 1. High mixing entropy - 2. Sluggish diffusion kinetics - 3. High lattice distortion - 4. Cocktail effect; Boron-free, silicon-free brazing materials for nickel superalloys to avoid brittle intermetallic and eutectic phase formation; Size-dependent melting point depression can eliminate the need for boron, silicon and other melting point depressants; A Ni-Mn-Fe-Co-Cu HEA with low solidus and liquidus temperatures (1080 °C and 1150 °C) was developed; Low solidus and liquidus temperatures of the HEA combined with the nanoscale melting point depression in this study; Bulk HEA fabricated by induction melting of elemental powders; HEA nanoparticles (NPs) fabricated by ball milling of the HEA micropowder; Inconel 718 was laser brazed in air using the HEA and bulk and NP performances are compared.

Bridges, Denzel↗
DOE OSTI2019

Fe-based ceramic nanocomposite membranes fabricated via e-spinning and vacuum filtration for Cd 2+ ions removal

Here, vacuum filtered and polymer mixed e-spinning membranes (ESPMs) made from or doped with Fe-based nanomaterials were successfully fabricated to remove Cd 2+ ions from a neutral aqueous solution. The used Fe-based nanomaterials including FeOOH precursor Nanowires (NWs), α-Fe 2 O 3 NWs and Fe 3 O 4 nanoparticles (NPs) were synthesized by elevating the hydrothermal reaction temperature from 250 °C to 500 °C or doing post-heating treatment. The adsorption results showed that vacuum filtered membranes (VFMs) overall performed a better Cd 2+ ions removal behavior than e-spinning ones. Among them, VFM made from Fe 3 O 4 NPs has the highest adsorption capacity (qt) with the adsorption amount of Cd 2+ ions reaching about 29.3 mg/g within only 2 min due to the high specific surface area of NPs. Models of pseudo-first-order, pseudo-second-order and intraparticle diffusion were used to study the kinetics of Cd 2+ ions removal process, and a high correlation coefficient (R 2 ) of 0.99 was obtained when pseudo-second-order model was used. It was measured that the equilibrium rate constant of VFM made from Fe 3 O 4 NPs has reached about 0.28 g mg –1 min –1 , much smaller than those of other membranes, which suggested a high Cd 2+ ions removal efficiency.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Direct-Write Printed Current Sensor for Load Monitoring Applications

We report on a flexible current sensor development employing direct-write printing and additive manufacturing techniques. The integrated current sensor unit incorporates sensing, data processing & storage, and in-field calibration capabilities. A combination of direct-write printing technique and low-temperature curable metallic ink is used to print Ag wires around a 12.5-μm -thick permalloy film. The overall thickness of the polyimide substrate and permalloy sheet remains well-below 500 μm enabling wrap-around sensor functionality. Fused deposition modeling (FDM) additive manufacturing is used to build custom parts for sensor mounting, encapsulation, and an in-field calibration unit using heat and chemical-resistant thermoplastic which responds well to mechanical stress. In the present configuration, the integrated current sensor unit can be powered through USB or 4 AAA batteries to allow data collection and sensor calibration in the field. The flexible current sensor employing a continuous sheet of the permalloy exhibited a well-behaved signal output response at peak current levels exceeding 15A and in the applied ac frequency range of 60 Hz–10 kHz. Overall, the combination of direct-write printing, thin permalloy material, and additive manufacturing technique shows promise for the development of a reconfigurable low-cost current sensor that can be deployed in large numbers at locations of interest to avail the cost and energy-saving opportunities in industrial/commercial and residential applications.

Yu, Yongchao↗
DOE OSTI2018

Laser-Induced Carbon-Based Smart Flexible Sensor Array for Multiflavors Detection

We report a flexible sensor array electronic tongue system that is fabricated on a polymer substrate by the laser direct writing process for multiflavor detection. Electronic tongue is a sensing system that is applied to detect different elements with the same sensor array. By analyzing responses from different measurement units, it enables a cross-sensitivity, namely, the ability of the system to responding to a range of different analytes in solution without specific functionalization of sensors. In this article, a six-unit sensing array system was fabricated by a laser direct writing process. Sensing units were introduced on a flexible polyamide surface. A high surface–volume ratio porous carbon structure was created by a laser-induced carbonization process, which provides stable conductive carbon electrodes with high sensitivity. Different surface treatments, such as gold plating, reduced-graphene oxide coating, and polyaniline coating, were accomplished for different measurement units. By applying principal component analysis, this sensing system shows a promising result for the detection of multiple flavors. The detection limit for each element is about 0.1 mM for NaCl and sugar solutions. Also, it is able to detect 10 –4 times diluted commercial table vinegar solution, which originally contains 5% acetic acid. The detection limit is theoretically lower than the human threshold of 10 mM for NaCl and sugar. Besides, the sensing system shows a high sensitivity and selectivity for mixed elements. Here, by mapping the data points, the sensor system could detect flavor combinations and provide a reliable prediction of analyte concentration ratios.

47 OTHER INSTRUMENTATION↗
DOE OSTI2018

Recent Progress on Laser Manufacturing of Microsize Energy Devices on Flexible Substrates

We report on the impact of laser processing on material and device performance characteristics for integrated energy applications. A femtosecond laser was used for development of flexible and transparent supercapacitors, while a nanosecond laser was successfully exploited for high-performance Al–air battery development. A laser direct-write process enabled integration of a three-dimensional-structured micro-supercapacitor on flexible polymer substrate, exhibiting peak specific capacitance of 42.6 mF/cm 2 at current density of 0.1 mA/cm 2 . Femtosecond laser processing was also exploited for development of a novel transparent supercapacitor on silk substrate. The MnO 2 -coated transparent supercapacitors exhibited high transmittance exceeding 59%. Laser processing in combination with printing technique was used for development of a novel Al–air battery. The nanosecond laser process was effective in sintering the anode printed using Al nanoparticle ink. The efficiency of the laser sintering process was reflected in good battery discharge performance.

25 ENERGY STORAGE↗
NASA NTRS2018

Preparation of Thick NI/AL Reactive Multilayer Films and Prospective Use for Self-Powered Brazing of TI-6AL-4V

In this study we demonstrate a new method for depositing thick reactive multilayer films (RMFs) (thickness > 14 µm) by using Ti interlayer integration and substrate preheating during fabrication. These two adjustments are designed to alleviate internal planar stresses that cause delamination between deposited layers and peeling off the substrate. Decreasing the distance between Ti interlayers helps to eliminate delamination between deposited layers. Through high speed camera measurements, the reaction propagation speed of an RMF sample with preheating is 42% slower than the same RMF that was not preheated, indicating a slower heat release rate. The preliminary experiments on brazing Ti-6Al-4V coated with BAlSi-4 brazing material revealed dendritic structure branching out from the RMF surface into the brazing material. The dendrite structures most likely form because of rapid melting and solidification of the brazing material. However, this rapid melting and solidification cycle does not appear to occur uniformly across the BAlSi-4RMF interface which is linked to its low bonding strength. When the Ti-6Al-4V substrate is heated to 150 °C prior to ignition, the strength increases to 0.47 MPa when the total RMF thickness is 84 µm and 15 MPa of pressure is applied.

Cheng, Jinquan↗
DOE OSTI2018

Colossal Photon Bunching Driven by Phonon Recombination Dynamics

We report photon bunching g(2)(0) ≈ 49 due to phonon sidebands in spectrally filtered cathodoluminescence from NV centers in diamond. The result is consistent with fast, phonon-mediated recombination dynamics, and supported by a stochastic model.

Feldman, Matthew A.↗
DOE OSTI2018

Laser Sintering of Printed Anodes for Al-Air Batteries

We report on a 3D printed Al anode for Al-air battery combined with laser sintering method. We verified that laser sintering contributed to effective removal of the organic solvent in the slurry and increased the conductivity of the printed anode. By application of infrared laser sintering, we significantly improved electrical contacts of Al nanoparticles and electrochemical performance of Al-air cells. A Pt/C coated hydrophobic carbon paper was used for air cathode to provide a good electrical contact, an oxygen flow ability, and the water sealing. Gel-style KOH was introduced as the electrolyte and waterways also utilized in the chemical reaction. The laser sintered Al-air battery could provide 239 mAh/g discharge capacity and a 0.95 V operation voltage. Also, a 3D structured anode was fabricated by 3D printing the active material on current collectors to achieve a high mass-loading with active material thickness of 360 μm, 560 μm and 680 μm for 1, 2 and 3 layers 3D printed electrodes. The battery cells provide areal discharge capacities of 1.5 mAh/cm 2 , 2.8mAh/cm 2 , and 3.23 mAh/cm 2 , respectively for 1, 2 and 3 layers-electrodes.

25 ENERGY STORAGE↗