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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Nickel hydroxide–nickel carbonate competitive growth on carbonate surfaces

The thermodynamic and kinetic factors controlling the competitive heterogeneous nucleation and growth of ubiquitous metal carbonate and hydroxide phases are poorly understood. In this work, calcite (CaCO 3 ) and magnesite (MgCO 3 ) powders were reacted with NiCl 2 (0–600 μM) for 7 days at 22 °C and 5 °C. The reacted powders were analyzed with X-ray photoelectron spectroscopy (XPS), scanning electron microscopy, and energy-dispersive X-ray spectroscopy to characterize the Ni surface precipitates formed. Evidence from these techniques pointed to the formation of mixed Ni carbonate-Ni hydroxide amorphous surface precipitates. On calcite, XPS detected primarily Ni(OH) 2 despite the initial solutions being more supersaturated with respect to gaspéite (NiCO 3 ) than to theophrastite (Ni(OH) 2 ) by a factor of 17–18. In contrast, NiCO 3 was the dominant component detected by XPS on magnesite in the same conditions. Decreasing the temperature had the effect of increasing the proportion of NiCO 3 to the detriment of Ni(OH) 2 . The experimental observations were consistent with low lattice/cation size mismatch favoring NiCO 3 nucleation and temperature most influencing Ni(OH) 2 nucleation. Comparison to previous work on Co-reacted powders indicated the differences in lattice/cation size mismatch and/or water exchange rate impacted the composition of the surface precipitates more than the relative thermodynamic stabilities of the competing minerals. This work explored the heterogeneous growth regime of Ni carbonate and hydroxide phases on carbonate surfaces and shed light on the factors that control the competition between surface precipitates when mineral surfaces are in contact with aqueous solutions supersaturated with respect to multiple mineral phases. In conclusion, these results contribute to geochemists’ efforts toward interpreting data from geochemical systems with elevated Ni concentrations, improving Ni environmental remediation and recovery strategies, and predicting the fate and transport of Ni in geochemical systems.

Heterogeneous nucleation↗
NASA NTRS1997

Studies of the Codeposition of Cobalt Hydroxide and Nickel Hydroxide

Topics considered include: chemistry, experimental measurements, planar film model development, impregnation model development, results and conclusion. Also included: effect of cobalt concentration on deposition/loading; effect of current density on loading distribution.

Ho, C. H.↗
NASA NTRS1986

Improvement of the process for electrochemical impregnation of nickel hydroxide electrodes

Nickel hydroxide electrodes containing 11g/dsqm hydroxide, with capacities of 3.6 to 3.8 Ah/dsqm were prepared at 353 K by electrochemical impregnation. The reproducibility of the results is obtained by readjusting the pH before each preparation. The control of each electrode is done during two cycles of charge and discharge following the manufacture by a potential relaxation method.

Comtat, M.↗
DOE OSTI2013

Preparation and supercapacitor application of the single crystal nickel hydroxide and oxide nanosheets

Graphical abstract: The nickel hydroxide and nickel oxide nanosheets prepared using CTAB at room temperature exhibit a high specific capacitance, prompt charge/discharge rate. - Highlights: • The nickel hydroxide nanosheets were prepared using CTAB at room temperature. • Ni(OH){sub 2} nanosheet can be successfully converted to NiO nanosheet via calcination. • The NiO nanosheet has a specific capacitance of 388 F g{sup −1} at 5 A g{sup −1} in KOH solution. • Anneal temperature impacts capacitive properties as electrode. - Abstract: The single crystalline Ni(OH){sub 2} nanosheets were synthesized by a simple chemical precipitation method using nickel chloride as precursors and ammonia as precipitating agent. The Ni(OH){sub 2} nanosheets were successfully converted to NiO nanosheets via calcination under appropriate conditions. Analytical methods such as X-ray diffraction (XRD) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and Fourier transformed infrared (FTIR) spectra were employed to characterize the morphology and microstructure of the final products. The experimental results revealed that Ni(OH){sub 2} nanosheets were shape-preserved transformed to NiO nanosheets at 250 °C for 24 h. Ni(OH){sub 2} and NiO nanosheets were directly functionalized as supercapacitor electrodes for potential energy storage applications, whose charge–discharge properties, electrochemical impedance spectra, cyclic voltammetry, and cycle performance were examined. The experimental results show that the single-crystalline NiO nanosheets are a promising candidate for the supercapacitor electrode. They exhibit a high specific capacitance, prompt charge/discharge rate.

36 MATERIALS SCIENCE↗
NASA NTRS1969

Cobalt improves nickel hydroxide electrodes for batteries

Positive nickel hydroxide electrodes containing 20 mole percent of cobalt hydroxide are more efficient than when impregnated to the same degree by weight with nickel hydroxide alone. Charge-acceptance and oxygen-evolution tests indicate cobalt electrodes are more efficient than plain positive nickel hydroxide electrodes at all rates of charge.

Lerner, S. R.↗
NASA NTRS1982

Nickel hydroxide electrode. 3: Thermogravimetric investigations of nickel (II) hydroxides

Water contained in Ni hydroxide influences its electrochemical reactivity. The water content of alpha and beta Ni hydroxides is different with respect to the amount and bond strength. Thermogravimetric experiments show that the water of the beta Ni hydroxides exceeding the stoichiometric composition is completely removed at 160 deg. The water contained in the interlayers of the beta hydroxide, however, is removed only at higher temperatures, together with the water originating from the decomposition of the hydroxide. These differences are attributed to the formation of II bonds within the interlayers and between interlayers and adjacent main layers. An attempt is made to explain the relations between water content and the oxidizability of the Ni hydroxides.

Dennstedt, W.↗
DOE OSTI2024

Thermal Conversion of Ultrathin Nickel Hydroxide for Wide Band Gap 2D Nickel Oxides

Wide band gap (WBG) semiconductors (E g > 2.0 eV) are integral to the advancement of next-generation electronics, optoelectronics, and power industries owing to their capability for high-temperature operation, high breakdown voltage, and efficient light emission. Enhanced power efficiency and functional performance can be attained through miniaturization, specifically via the integration of device fabrication into a two-dimensional (2D) structure enabled by WBG 2D semiconductors. However, as an essential subgroup of WBG semiconductors, 2D transition metal oxides (TMOs) remain largely underexplored in terms of physical properties and applications in 2D optoelectronic devices, primarily due to the scarcity of sufficiently large 2D crystals. Thus, our goal is to develop synthesis pathways for 2D TMOs possessing large crystal domains (e.g., >10 μm), expanding the 2D TMO family and providing insights for future engineering of 2D TMOs. Here, we demonstrate the synthesis of WBG 2D nickel oxide (NiO) (E g > 2.7 eV) thermally converted from 2D nickel hydroxide (Ni(OH) 2 ) with a lateral domain size larger than 10 μm. Moreover, the conversion process is investigated using various microscopic techniques, such as atomic force microscopy, Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy, providing significant insights into morphology and structural variations under different oxidative conditions. The electronic structure of the converted Ni x O y is further investigated using multiple soft X-ray spectroscopies, such as X-ray absorption and emission spectroscopies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Hydroxide Exchange Membrane Carbon Capture (HEMCC) Using Nickel Hydroxide Batteries and Flow-through Membranes

Proposed is an electrochemical nickel hydroxide based hydroxide exchange membrane carbon capture (HEMCC) device for Direct Air Capture (DAC) of CO2. DAC has been identified as one of the key net negative carbon technologies to achieve net zero carbon emissions. Net negative carbon technologies are required to offset continued emissions from dilute CO2 sources such as agriculture and construction. The majority of current DAC technologies at scale (>1 KT∙yr-1) are adsorbent based technologies with significant energy cost. The traditional DAC energy cost is primarily driven by the temperature swing required to regenerate the sorbent and has been shown to be 1.8 MWh·ton-1 at the system level. Electrochemical pH swing devices are a growing research area for carbon capture devices with the goal of lowering the energy cost required for DAC. A pH gradient is built by generating OH- at the cathode and consuming OH- at the anode. An acid-base equilibrium with CO2 allows for the capture of CO2 at the cathode and release at the anode. This extends from other electrochemical CO2 capture devices based on pKa shifts of an electrochemically active organic species allowing for the capture and release of CO2. Electrochemical CO2 capture is considered promising based on potentially low energy costs to capture CO2 in comparison with current temperature swing adsorption technologies. This work explores Ni(OH)2 electrodes to produce the pH gradient for CO2 capture and release. At the cathode NiOOH is reduced to Ni(OH)2 while at the anode Ni(OH)2 is oxidized to NiOOH. The symmetrical electrodes allow for a low voltage requirement; the thermodynamic potential difference of standard electrochemical reactions is zero. Most of the voltage observed is to produce the pH gradient with the remainder driving the polarization of the electrodes. There is a resistance component as well, but this is small in comparison due to the low current densities used in the device, nominally 2 mA·cm-1. Two similar devices are presented, a traditional MEA (membrane electrode assembly) and a flow-through MEA. The traditional MEA separates the two Ni(OH)2 electrodes with an 80μm Piperion® membrane. While the flow-through membrane separates the electrodes with a three piece membrane consisting of two 80μm Piperion® membranes with a porous membrane between them. In the traditional MEA system air is passed over the cathode for capture, while the flow-through MEA the air is passed through the porous membrane isolated from the electrodes. The traditional MEA has been used to establish a baseline performance of the device and has been shown to capture CO2 at an energy cost of 1 MWh·ton-1 at the device level. An understanding has been built around the components of that energy cost including the relationship of flux to current density, effect of a regeneration process, transient battery behavior, and gas losses coinciding with changing the polarization of the batteries. The flow-through MEA looks to address of transient battery behavior and gas losses. It allows for denser, higher capacity electrodes, which can lean on traditional Ni-MH battery technology used in alkaline batteries used today. The higher capacities, limit the transient battery effect on flux in the device. Gas losses are addressed by having a continuous inlet air stream to the device and continuous outlet product.

Buchen, James↗
DOE OSTI2018

Nickel hydroxide positive electrode for alkaline rechargeable battery

Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

25 ENERGY STORAGE↗
DOE OSTI2018

Nickel hydroxide positive electrode for alkaline rechargeable battery

Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

25 ENERGY STORAGE↗
NASA NTRS1987

Electrochemical impregnation of nickel hydroxide in porous electrodes

The electrochemical impregnation of nickel hydroxide in porous electrode was investigated both experimentally and theoretically. The loading level and plaque expansion were the most important parameters to be considered. The effects of applied current density, stirring, ratio of solution to electrode volume and pH were identified. A novel flow through electrochemical impregnation is proposed in which the electrolyte is forced through the porous nickel plaque. The thickening of the plaque can be reduced while maintaining high loading capacity. A mathematical model is presented which describes the transport of the nitrate, nickel and hydroxyl ions and the consecutive heterogeneous electrochemical reduction of nitrate and the homogeneous precipitation reaction of nickel hydroxide. The distributions of precipitation rate and active material within the porous electrode are obtained. A semiempirical model is also proposed which takes into account the plugging of the pores.

Ho, Kuo-Chuan↗
DOE OSTI2013

Structure and electrochemical properties of nanometer Cu substituted α-nickel hydroxide

Graphical abstract: Display Omitted Highlights: ► Cu substituted α-nickel hydroxide was prepared by ultrasonic assisted precipitation. ► The XRD peaks are anisotropic broadening. ► The electrode for 0.9 wt.% Cu has the highest capacity of 310 mAh/g at 0.2 C. -- Abstract: Nanometer Cu-substituted α-nickel hydroxide was synthesized by means of ultrasonic-assisted precipitation. Particle size distribution (PSD) measurement, X-ray diffraction (XRD), and high-resolution transmission electron microscope (HR-TEM) were used to characterize the physical properties of the synthesized samples. The results indicate that the average particle size of the samples is about 96–110 nm and the XRD diffraction peaks are anisotropic broadening. The crystal grains are mainly polycrystal structure with columnar or needle-like morphology, containing many defects. With increase of Cu content, the shape of primary particles transform from columnar to needle-like. The influences of doping amounts of Cu on the electrochemical performance were investigated through constant current charge/discharge and cyclic voltammetric measurements. The specific capacity increases initially and then decreases with increasing Cu-doping ratio, the electrode C containing 0.9 wt.% Cu shows the maximum discharge capacity of 310 mAh/g at 0.2 C, and it has the lowest charging voltage, higher discharge voltage plateau, better cycle performance and larger proton diffusion coefficient than the other electrodes.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Formation of {beta}-nickel hydroxide plate-like structures under mild conditions and their optical properties

Nanostructural {beta}-nickel hydroxide ({beta}-Ni(OH){sub 2}) plates were prepared using the microwave-hydrothermal (MH) method at a low temperature and short reaction times. An ammonia solution was employed as the coordinating agent, which reacts with [Ni(H{sub 2}O){sub 6}]{sup 2+} to control the growth of {beta}-Ni(OH){sub 2} nuclei. A trigonal {beta}-Ni(OH){sub 2} single phase was observed by X-ray diffraction (XRD) analyses, and the crystal cell was constructed with structural parameters and atomic coordinates obtained from Rietveld refinement. Field emission scanning electron microscopy (FE-SEM) images revealed that the samples consisted of hexagonal-shaped nanoplates with a different particle size distribution. Broad absorption bands assigned as transitions of Ni{sup 2+} in oxygen octahedral sites were revealed by UV-vis spectra. Photoluminescence (PL) properties observed with a maximum peak centered in the blue-green region were attributed to different defects, which were produced during the nucleation process. We present a growth process scheme of the {beta}-Ni(OH){sub 2} nanoplates. - Graphical abstract: Nanostructural {beta}-Ni(OH){sub 2} crystalline powders were prepared by rapid microwave-hydrothermal method for 1, 8 and 32 min. The hexagonal-shaped nanoplates obtained presented PL emission in the blue-green region and each decomposed component represents a different type of electronic transition, which can be linked to the structural arrangement or surface defects. Highlights: > Ammonia solution to control the growth of {beta}-Ni(OH){sub 2} nuclei. > Regular plates-shape related to crystallization-dissolution-recrystallization. > The surface states and lattice defects generated in growth mechanism of crystals. > Different defects produced in the growth process responsible by photoluminescence. > Each component of photoluminescence curve linked to structural arrangement or surface defects.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Direct Air Capture of Carbon Dioxide Using Nickel Hydroxide Batteries in a Membrane Electrode Assembly

Direct air capture (DAC) is a growing field responding to the need to remove carbon dioxide from the atmosphere. Several technologies are being developed today attempting to meet this need. The technology furthest in development are temperature swing adsorption technologies which have recently moved out of the pilot plant scale.1 This presentation looks to present an electrochemical device as alternative to these technologies. The electrochemical device proposed is a pair of nickel hydroxide (Ni(OH)2) battery electrodes which produce hydroxide (OH-). The hydroxide reacts with carbon dioxide (CO2) to create carbonate (CO32-) and bicarbonate (HCO3-). These carbonates can be transported from the cathode across an anion exchange membrane to the anode where they are evolved back into CO2 due to a pH reduction at the anode. This builds on work that optimized a Hydroxide Exchange Membrane Fuel Cell (HEMFC) for CO2 capture, showing the efficacy of an electrochemically mediated pH swing carbon capture device.2,3 The benefit of the nickel hydroxide battery approach is the low energy cost associated with separation. Because a pair of nickel hydroxide batteries undergo the same electrochemical reaction, low potentials, and thus low energy cost is required. Experiments have shown device level energy requirements of less than 1 MWh ton-1CO2. Most of the energy required by the device produces the pH gradient used to capture and release CO2. The biggest hurdle for this electrochemical approach is increasing the flux of CO2 to allow for more compact devices. Strategies for managing the transient charge and discharge behavior of the battery system will be discussed. Focus will be on improving flux to reduce the overall cost of the device.

Buchen, James↗