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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2

The Role and Substitution of Cobalt in the Cobalt‐Lean/Free Nickel‐Based Layered Transition Metal Oxides for Lithium Ion Batteries

Here, the Nickel-based layered transition metal oxide cathode represented by NCM (LiNi x Co y Mn z O 2 , x+y+z=1) and NCA (LiNi x Co y Al z O 2 , x+y+z=1) is widely used in the electric vehicle market due to its specific capacity and high working potential, in which Cobalt (Co) plays a huge role in improving the structural stability during the cycle. However, the limited supply of Co, due to its scarcity and the influence of geopolitics, poses a significant constraint on the further advancement of the Nickel-based layered transition metal oxide cathode in the field of energy storage. In this paper, the mechanism of Co in the Nickel-based layered transition metal oxides is reviewed, including its critical role for structural stability such as the inhibition of cationic mixing and the release of lattice oxygen et al. Subsequently, it outlines various strategies to enhance the performance of Co-lean/free materials, such as ion doping, including single-ion doping and multi-ion co-doping, and various surface coating strategies, so as to eliminate the adverse effects of Co loss on materials. Ultimately, this paper offers a glimpse into the promising future of Cobalt-free strategies for high performance of Nickel-based layered transition metal oxides.

25 ENERGY STORAGE↗

Temperature effects on cobalt hydroxide–cobalt carbonate competitive growth on carbonate surfaces

Cobalt (Co), a critical metal essential for various environmental and industrial processes, undergoes speciation and immobilization in natural systems, primarily interacting with existing mineral surfaces. Understanding the underlying mechanisms of Co immobilization on abundant carbonate surfaces under different environmental conditions is critical for predicting Co mobility, availability, and recovery. In this study, we investigated the temperature-dependent competition between CoCO 3 and Co(OH) 2 formation on calcite (CaCO 3 ) and magnesite (MgCO 3 ) surfaces. Using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), we analyzed carbonate substrates exposed to CoCl 2 solutions at varying concentrations (0–500 μM) and temperatures (22, 50, and 80 °C). Magnesite surfaces promoted CoCO 3 formation due to its low lattice mismatch with sphaerocobaltite (CoCO 3 ). However, this slow-growing CoCO 3 component was progressively outcompeted by Co(OH) 2 formation as the temperature and/or initial Co concentration increased. On calcite surfaces, the poor lattice mismatch between calcite and sphaerocobaltite led to Co(OH) 2 outcompeting CoCO 3 formation at all three temperatures. These findings provide critical insights into the roles of substrate composition, solution chemistry, and temperature in controlling Co speciation and mobility. They carry important implications for environmental transport, geochemical cycling, and industrial recovery of cobalt in carbonate-rich systems.

Calcite↗

Superior Fischer-Tropsch Performance of Uniform Cobalt Nanoparticles Deposited into Mesoporous SiC

Electrochemically-derived well-crystalline mesoporous silicon carbide (pSiC) was used to host cobalt nanoparticles and to show superior catalytic performance during the CO hydrogenation according to Fischer-Tropsch. Colloidal metal particles (9 ± 0.4 nm) were prepared independently before depositing them into pSiC and, for comparison purposes, into commercially available silica (Davisil) and foam-like MCF-17 supports. The Co/pSiC catalyst demonstrated the highest catalytic activity of 117 ?molCO gCo-1 s-1 at 220 °C in the Fischer-Tropsch reaction, while the silica supported cobalt samples showed about one order of magnitude less activity. A significant increase in the C5+ hydrocarbons selectivity for Co/pSiC was observed. The stable performance of the catalyst is attributed to the high dispersion of the active phase and the use of silicon carbide acting as a thermally conductive and chemically inert porous support.

lablokou, V. S.↗

A Cobalt– and Manganese–Free High–Nickel Layered Oxide Cathode for Long–Life, Safer Lithium–Ion Batteries

High-nickel LiNi 1–x–y Mn x Co y O 2 and LiNi 1–x–y Co x Al y O 2 cathodes are receiving growing attention due to the burgeoning demands on high-energy-density lithium-ion batteries. The presence of both cobalt and manganese in them, however, triggers multiple issues, including high cost, high toxicity, rapid surface deterioration, and severe transition-metal dissolution. Herein, a Co- and Mn-free ultrahigh-nickel LiNi 0.93 Al 0.05 Ti 0.01 Mg 0.01 O 2 (NATM) cathode that exhibits 82% capacity retention over 800 deep cycles in full cells, outperforming two representative high-Ni cathodes LiNi 0.94 Co 0.06 O 2 (NC, 52%) and LiNi 0.90 Mn 0.05 Co 0.05 O 2 (NMC, 60%) is presented. It is demonstrated that a titanium-enriched surface along with aluminum and magnesium as the stabilizing ions in NATM not only ameliorates unwanted side reactions with the electrolyte and structural disintegrity, but also mitigates transition-metal dissolution and active lithium loss on the graphite anode. As a result, the graphite anode paired with NATM displays an ultrathin (≈8 nm), monolayer anode-electrolyte interphase architecture after extensive cycling. Furthermore, NATM displays considerably enhanced thermal stability with an elevated exothermic temperature (213 °C for NATM vs 180 and 190 °C for NC and NMC, respectively) and remarkably reduced heat release. This work sheds light on rational compositional design to adopt ultrahigh-Ni cathodes in lithium-based batteries with low cost, long service life, and improved thermal stability.

25 ENERGY STORAGE↗

Proton-Coupled Electron Transfer Mechanisms for CO 2 Reduction to Methanol Catalyzed by Surface-Immobilized Cobalt Phthalocyanine

Immobilized cobalt phthalocyanine (CoPc) is a highly promising architecture for the six-proton, six-electron reduction of CO 2 to methanol. This electroreduction process relies on proton-coupled electron transfer (PCET) reactions that can occur by sequential or concerted mechanisms. Immobilization on a conductive support such as carbon nanotubes or graphitic flakes can fundamentally alter the PCET mechanisms. We use density functional theory (DFT) calculations of CoPc adsorbed on an explicit graphitic surface model to investigate intermediates in the electroreduction of CO 2 to methanol. Our calculations show that the alignment of the CoPc and graphitic electronic states influences the reductive chemistry. These calculations also distinguish between charging the graphitic surface and reducing the CoPc and adsorbed intermediates as electrons are added to the system. This analysis allows us to identify the chemical transformations that are likely to be concerted PCET, defined for these systems as the mechanism in which protonation of a CO 2 reduction intermediate is accompanied by electron abstraction from the graphitic surface to the adsorbate without thermodynamically stable intermediates. Furthermore, this work establishes a mechanistic pathway for methanol production that is consistent with experimental observations and provides fundamental insight into how immobilization of the CoPc impacts its CO 2 reduction chemistry.

Adsorption↗

Electromagnetic containerless reaction of samarium with cobalt for the formation of samarium-cobalt alloys

The electromagnetic levitation technique has been used to obtain nearly stoichiometric SmCo5, with the reaction temperature controlled by a gas jet. The results of several experiments carried out at a 450 kHz, 25 kw RF power levitation facility using different reaction times and cooling rates are presented. It is shown that reaction rates achieved with the levitation technique are larger than the expected diffusion rate in the system liquid samarium-solid cobalt. It is also shown that substantial mixing occurs in the RF-levitated melt.

Chang, C. W.↗

Low-cobalt and cobalt-free, high-energy cathode materials for lithium batteries

Described herein are low or no-cobalt materials useful as electrode active materials in a cathode for lithium or lithium-ion batteries. For example, compositions of matter are described herein, such as electrode active materials that can be incorporated into an electrode, such as a cathode. The disclosed electrode active materials exhibit high specific energy and voltage, and can also exhibit high rate capability and/or long operational lifetime.

Manthiram, Arumugam↗

Cobalt-Group 13 Complexes Catalyze CO 2 Hydrogenation via a Co(-I)/Co(I) Redox Cycle

The Co(-I) dihydrogen complexes, [(η 2 -H 2 )CoML]-, where ML is the group 13 metalloligand, N(o-(NCH 2 PiPr 2 )C 6 H 4 ) 3 M, and M is Al, Ga, or In, were previously reported ( J. Am. Chem. Soc. 2017, 139, 6570-6573). In this work, the related Co(-I) end-on dinitrogen adducts, [(N 2 )CoML]-, were isolated and investigated as precatalysts for CO 2 hydrogenation. The Co–Ga catalyst was highly active, achieving 19,200 formate turnovers with an initial turnover frequency of 27,000 h –1 under 34 atm of 1:1 CO 2 /H 2 and using Verkade’s proazaphosphatrane as a base at ambient temperature. The Co–Al catalyst was moderately active, while the Co–In complex was inactive. Hence, tuning the group 13 ion greatly influences the catalytic activity at the Co site. To elucidate the role of the group 13 support, experimental and theoretical mechanistic studies of the Co–Ga and Co–Al catalysts were conducted. The Co(-I) H 2 species are potent hydride donors with estimated thermodynamic hydricities (ΔG° H– ) of 32.0(1) and 37.4(1) kcal/mol in CH 3 CN for M = Al and Ga, respectively. By acting as masked Co(I) dihydrides, the Co(-I) H 2 species operate via an unusual Co(-I)/Co(I) redox cycle. After hydride transfer to CO 2 , the resulting intermediate is the Co(I) hydride complex, HCoML, which was independently synthesized and structurally characterized for M = Al and Ga. The Gibbs free energy for H 2 binding, ΔG° bind (1 atm), to generate (η 2 -H 2 )HCoML was slightly more favorable for HCoGaL (-4.2(1) kcal/mol) than for HCoAlL (-2.7(1) kcal/mol). In the subsequent step, the deprotonation reaction to regenerate the initial catalyst was much more favorable for (η 2 -H 2 )HCoGaL (pK a of 31.4, CH 3 CN) than for (η 2 -H 2 )HCoAlL (pK a of 34.3). Finally, the straightforward substitution of Al with Ga perturbs the energy profile of the catalytic reaction (|ΔΔG° H– | = 5.4 kcal/mol, |ΔΔG° bind | = 1.5 kcal/mol, and |ΔΔG° K a | = 4.0 kcal/mol) and thus provides a thermodynamic rationale for the higher catalytic efficiency of Co–Ga over Co–Al.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗