Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “cathode materials”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Propagation topography of redox phase transformations in heterogeneous layered oxide cathode materials

Redox phase transformations are relevant to a number of metrics pertaining to the electrochemical performance of batteries. These phase transformations deviate from and are more complicated than the conventional theory of phase nucleation and propagation, owing to simultaneous changes of cationic and anionic valence states as well as the polycrystalline nature of battery materials. Herein, we propose an integrative approach of mapping valence states and constructing chemical topographies to investigate the redox phase transformation in polycrystalline layered oxide cathode materials under thermal abuse conditions. We discover that, in addition to the three-dimensional heterogeneous phase transformation, there is a mesoscale evolution of local valence curvatures in valence state topographies. The relative probability of negative and positive local valence curvatures alternates during the layered-to-spinel/rocksalt phase transformation. In conclusion, the implementation of our method can potentially provide a universal approach to study phase transformation behaviors in battery materials and beyond.

25 ENERGY STORAGE↗
DOE OSTI2020

LiNi x Fe y Al z O 2 , a new cobalt-free layered cathode material for advanced Li-ion batteries

Recently, rapid fluctuations in cobalt prices have created a worsening supply chain constraint that has become a serious cause of concern amidst global battery manufacturers. To address this challenge, we report herein a new class of cobalt-free, nickel-rich layered cathode material termed the NFA class with general formula LiNi x Fe y Al z O 2 (x + y + z = 1). Using co-precipitation reaction in a continuous stirred tank reactor, we synthesized NFA(OH) 2 precursors with the constituent Ni, Fe and Al elements successfully incorporated. The obtained LiNFAO 2 cathode was characterized using X-Ray diffraction, Mössbauer spectroscopy and scanning electron microscopy. Electrochemical behavior was assessed using cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy and galvanostatic intermittent titration technique at various states of lithiation/delithiation. Electrochemical performance evaluations revealed that our cobalt-free material delivers high capacity of 190 mAh/g at 0.1C. Rate and cycling performance evaluations also indicated good rate capability and cycling stability with 88% capacity retention after 100 cycles at C/3. Using NFA cathodes, we also fabricated a 0.5Ah (C/3) cobalt-free Li-ion battery which demonstrated reasonable cycling stability with ~72% capacity retained after 200 cycles. Overall, our work demonstrates the immense potential of the cobalt-free NFA class cathodes as viable candidates towards development of next generation cost effective lithium ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2021

Synthesis and Processing by Design of High-Nickel Cathode Materials

The high demand of lightweight, high energy density batteries for energy storage promotes new materials discovery and development. Despite the large number of battery materials being discovered, very few of them have been commercially deployed, mostly bottlenecked by synthesis and processing – namely, making certain phases with the desired structure and properties to meet the multifaceted performance requirements. Alternative to the traditional trial and error, we present here an in situ study aided synthesis- and processing-by-design approach. With specific examples, we illustrate how to use the approach to identify reaction pathways in synthesis and processing of high-Nickel (Ni) cathode materials for next-generation lithium-ion batteries, thereby ensuring precise control of their structure, morphology, and surface properties. Furthermore, perspectives are provided on the wide applicability of the approach to solving critical issues inherent to high-Ni cathodes and the new directions and opportunities in the area.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Selectively extracting lithium from single and mixed cathode materials

With the burgeoning reliance on lithium-ion batteries for sustainable energy solutions and electric transportation, the environmental and resource management associated with battery disposal are increasingly critical. Addressing these challenges necessitates innovative recycling techniques that recover valuable battery components, particularly lithium. This research introduces a universal, eco-friendly approach tailored for the efficient selective extraction of lithium from both single and mixed cathode materials, achieving impressive selective leaching efficiencies of lithium (99.51 % for LFP, 90 % for NMC, and 97.24 % for mixed cathode). Surprisingly, leaching efficiency of lithium from NMC can be significantly improved by introducing LFP since LFP can remove the dense transition-metal salts on the surface of NMC. The extracted lithium is recovered as lithium carbonate with battery-grade purity. This study also highlights the reuse of formic acid and the adoption of oxygen as an oxidizing agent to prevent wastewater production. Therefore, this method provides a robust foundation for sustainable lithium battery recycling.

economically and environmentally feasible↗
DOE OSTI2020

Sample Dependence of Magnetism in the Next-Generation Cathode Material LiNi 0.8 Mn 0.1 Co 0.1 O 2

We present a structural and magnetic study of two batches of polycrystalline LiNi 0.8 Mn 0.1 Co 0.1 O 2 (commonly known as Li NMC 811), a Ni-rich Li ion battery cathode material, using elemental analysis, X-ray and neutron diffraction, magnetometry, and polarized neutron scattering measurements. We find that the samples, labeled S1 and S2, have the composition Li 1–x Ni 0.9+x–y Mn y Co 0.1 O 2 , with x = 0.025(2), y = 0.120(2) for S1 and x = 0.002(2), y = 0.094(2) for S2, corresponding to different concentrations of magnetic ions and excess Ni 2+ in the Li + layers. Both samples show a peak in the zero-field-cooled (ZFC) dc susceptibility at 8.0(2) K, but the temperature at which the ZFC and FC (field-cooled) curves deviate is substantially different: 64(2) K for S1 and 122(2) K for S2. The ac susceptibility measurements show that the transition for S1 shifts with frequency whereas no such shift is observed for S2 within the resolution of our measurements. Our results demonstrate the sample dependence of magnetic properties in Li NMC 811, consistent with previous reports on the parent material LiNiO 2 . Here, we further establish that a combination of experimental techniques is necessary to accurately determine the chemical composition of next-generation battery materials with multiple cations.

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

High performance layered cathode materials for high voltage sodium-ion batteries

A cathode active material includes NaxMO2 having at least a first phase, a second phase different from the first phase, and a third phase that is different from the first and second phases, wherein each phase is independently selected from Pm or On, where m and n are individually an integer, M is a transition metal or a mixture of transition metals, and x is greater than 0 and less than or equal to 1.

25 ENERGY STORAGE↗
DOE OSTI2022

Binary Fe/Mn-Based Nanocomposites as Li-Free Cathode Materials for Li Batteries Assembled in Charged State

Li-ion batteries play important roles in this mobile society. The ever-increasing demand for energy storage, particularly from electric vehicles, requires next-generation Li batteries with higher energy density and better safety. In contrast to existing Li-ion batteries using lithiated cathodes and Li-free anodes, we explore Li-free cathodes coupled with lithium/ lithiated anodes in order to construct new Li batteries assembled in a charged state. Here, two highly promising Li-free cathode materials of 1-D FeOF nanorods and 2-D monolayer MnO 2 nanosheets are integrated to make FeOF@MnO 2 nanocomposites. FeOF nanorods are sandwiched by monolayer MnO 2 nanosheets where FeOF nanoparticles could prevent the restacking of the monolayer MnO 2 nanosheets and the presence of monolayer MnO 2 nanosheets could enhance the electrical integration of the FeOF nanorods. Synergistic effects of the binary Fe/Mn-based cathodes can lead to both high voltage and high capacity, compared to individual components. Electrochemical evaluation reveals that binary Fe/Mn-based Li-free cathodes demonstrate promising performances and are worthy of further investigation and optimization.

25 ENERGY STORAGE↗
DOE OSTI2014

Surface modified CF x cathode material for ultrafast discharge and high energy density

Li/CF x primary possesses the highest energy density of 2180 W h kg⁻¹ among all primary lithium batteries. However, a key limitation for the utility of this type of battery is in its poor rate capability because the cathode material, CF x , is an intrinsically poor electronic conductor. Here, we report on our development of a controlled process of surface de-fluorination under mild hydrothermal conditions to modify the highly fluorinated CF x . The modified CF x , consisting of an in situ generated shell component of F-graphene layers, possesses good electronic conductivity and removes the transporting barrier for lithium ions, yielding a high-capacity performance and an excellent rate-capability. Indeed, a capacity of 500 mA h g⁻¹ and a maximum power density of 44 800 W kg⁻¹ can be realized at the ultrafast rate of 30 C (24 A g⁻¹), which is over one order of magnitude higher than that of the state-of-the-art primary lithium-ion batteries.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Simultaneous oxygen and boron trifluoride functionalization of hexagonal boron nitride: a designer cathode material for energy storage

Covalent functionalization is a way to tune the electrochemical properties of hexagonal boron nitride (h-BN) monolayers. The wide bandgap insulator h-BN may become metallic conductor upon functionalization with strong oxidants, such as (fluorosulfonyl)oxy radicals (·OSO 2 F), as known since 1978 ( Bartlett et al in J Chem Soc Chem Commun 5:200, 1978), with electrical conductivity of 1.5 S/cm (Shen et al in J Solid State Chem 147:74, 1999) that greatly surpasses commercial cathode material Li x CoO 2 while retaining excellent ionic conductivity. Functionalized boron nitrides (FBN-s) have great potential for cathode applications in energy storage devices, for example, in solid-state batteries. While (fluorosulfonyl)oxy functionalization is unlikely to result in rechargeable cathodes, similarly to graphene fluoride (CF x ), some other FBN-s discussed here may do. In the present work, fluorene, oxygen and combined oxygen and boron trifluoride functionalizations are studied, on the basis of band structure calculations. Due to the open surfaces of FBN-s, fast ionic diffusion with Li, Na and Mg ions is possible, enabling batteries with voltages of 2.1–5.6 V, theoretical energy densities of 800–1200 Wh/kg and fast charge and discharge.

Chemistry↗
DOE OSTI2021

Scaling up of High-Performance Single Crystalline Ni-rich Cathode Materials (CRADA 509)

This is a collaborative effort between Battelle Memorial Institute as manager and operator of Pacific Northwest National Laboratory (PNNL) and Albemarle Corporation (“Participant”) to develop and scale up an innovative and low-cost synthesis approach for preparing high-performance single crystalline Ni-rich cathode materials, i.e., LiNi0.8Mn0.1Co0.1O2 (NMC811) and LiNi0.9Mn0.05Co0.05O2 (NMC90) for next-generation LIBs. At the end of this project, the team will (1) develop a cost-effective synthesis approach for preparing single crystalline MNC811 (>200 mAh/g) and NMC90 (>210 mAh/g) by using advanced lithium salts, (2) address the performance issues of single crystals prepared from large-scale synthesis, and (3) demonstrate the processing/scaling up capabilities of up to 1 kg/batch of high-performance NMC811 and NMC90 single crystals.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Interplay of cation and anion redox in Li 4 Mn 2 O 5 cathode material and prediction of improved Li 4 (Mn,M) 2 O 5 electrodes for Li-ion batteries

Significant research effort has focused on improving the specific energy of lithium-ion batteries for emerging applications, such as electric vehicles. Recently, a rock salt–type Li 4 Mn 2 O 5 cathode material with a large discharge capacity (~350 mA·hour g –1 ) was discovered. However, a full structural model of Li 4 Mn 2 O 5 and its corresponding phase transformations, as well as the atomistic origins of the high capacity, warrants further investigation. We use first-principles density functional theory (DFT) calculations to investigate both the disordered rock salt–type Li 4 Mn 2 O 5 structure and the ordered ground-state structure. The ionic ordering in the ground-state structure is determined via a DFT-based enumeration method. We use both the ordered and disordered structures to interrogate the delithiation process and find that it occurs via a three-step reaction pathway involving the complex interplay of cation and anion redox reactions: (i) an initial metal oxidation, Mn 3+ →Mn 4+ (Li x Mn 2 O 5 , 4 > x > 2); (ii) followed by anion oxidation, O 2– → O 1– (2 > x > 1); and (iii) finally, further metal oxidation, Mn 4+ → Mn 5+ (1 > x > 0). This final step is concomitant with the Mn migration from the original octahedral site to the adjacent tetrahedral site, introducing a kinetic barrier to reversible charge/discharge cycles. Armed with this knowledge of the charging process, we use high-throughput DFT calculations to study metal mixing in this compound, screening potential new materials for stability and kinetic reversibility. We predict that mixing with M = V and Cr in Li 4 (Mn,M) 2 O 5 will produce new stable compounds with substantially improved electrochemical properties.

25 ENERGY STORAGE↗
DOE OSTI2019

Influence of the composition on the electrochemical properties of cathode materials {sub x}Li{sub 2}MnO{sub 3}•(1–x)LiMn{sub 1/3}Ni{sub 1/3}Co{sub 1/3}O{sub 2} for lithium-ion batteries

Lithium-rich transition metal complex oxides of the general composition xLi{sub 2}MnO{sub 3}• •(1–x)LiMO{sub 2} (M = Mn{sub a}Ni{sub b}Co{sub c}, a + b + c = 1) were synthesized by coprecipitation and modified Pechini method. The influence of the oxide phase composition on their electrochemical performance as cathode materials was studied in lithium half-cells. Effects of the synthetic approach and synthesis conditions on the morphology and electrochemical characteristics of the materials obtained were considered. The composition 0.35Li{sub 2}MnO{sub 3}• •0.65LiMn{sub 1/3}Ni{sub 1/3}Co{sub 1/3}O{sub 2} demonstrates the highest discharge capacity retention during cycling. The samples with discharge capacity of 290 mA h g{sup –1} were obtained.

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

A dicyanobenzoquinone based cathode material for rechargeable lithium and sodium ion batteries

Organic quinone materials allow a sustainable approach for electric energy storage, yet, their intrinsic electrical insulation and dissolution into the electrolyte during cycling have hampered their wide applications. To handle these two issues, we have synthesized a novel organic cathode material by anchoring a quinone compound, 2,3-dicyano- p -benzoquinone (DCBQ) with a high redox potential of 3.37 V vs. Li/Li + , onto carbon nanotubes (CNTs) (CNTs-DCBQ) through a facile ‘‘grafting to’’ method. The elaborate combination of excellent electron conductivity and large surface area of CNTs and stable and reversible redox reaction of DCBQ enables CNTs-DCBQ to deliver high reversible capacities of 206.9 and 175.8 mA h g –1 at a current density of 10 mA g –1 and also remarkable capacities of 110.2 and 82.1 mA h g –1 at a higher current density of 200 mA g –1 with a capacity retention approaching 100% after 1000 cycles for lithium and sodium ion batteries, respectively.

25 ENERGY STORAGE↗
DOE OSTI2021

Revisiting Discharge Mechanism of CF x as a High Energy Density Cathode Material for Lithium Primary Battery

Lithium/fluorinated graphite (Li/CFx) primary batteries show great promise for applications in a wide range of energy storage systems due to their high energy density (>2100 Wh kg –1 ) and low self-discharge rate (<0.5% per year at 25 °C). While the electrochemical performance of the CF x cathode is indeed promising, the discharge reaction mechanism is not thoroughly understood to date. In this article, a multiscale investigation of the CF x discharge mechanism is performed using a novel cathode structure to minimize the carbon and fluorine additives for precise cathode characterizations. Titration gas chromatography, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, cross-sectional focused ion beam, high-resolution transmission electron microscopy, and scanning transmission electron microscopy with electron energy loss spectroscopy are utilized to investigate this system. Results show no metallic lithium deposition or intercalation during the discharge reaction. Crystalline lithium fluoride particles uniformly distributed with <10 nm sizes into the CF x layers, and carbon with lower sp2 content similar to the hard-carbon structure are the products during discharge. This article deepens the understanding of CF x as a high energy density cathode material and highlights the need for future investigations on primary battery materials to advance performance.

25 ENERGY STORAGE↗
DOE OSTI2023

Unlocking the Potential of A-Site Ca-Doped LaCo 0.2 Fe 0.8 O 3-δ : A Redox-Stable Cathode Material Enabling High Current Density in Direct CO 2 Electrolysis

Massive carbon dioxide (CO 2 ) emission from recent human industrialization has affected the global ecosystem and raised great concern for environmental sustainability. The solid oxide electrolysis cell (SOEC) is a promising energy conversion device capable of efficiently converting CO 2 into valuable chemicals using renewable energy sources. However, Sr-containing cathode materials face the challenge of Sr carbonation during CO 2 electrolysis, which greatly affects the energy conversion efficiency and long-term stability. Thus, A-site Ca-doped La1– x CaxCo 0.2 Fe 0.8 O 3-δ (0.2 ≤ x ≤ 0.6) oxides are developed for direct CO 2 conversion to carbon monoxide (CO) in an intermediate-temperature SOEC (IT-SOEC). With a polarization resistance as low as 0.18 O cm 2 in pure CO 2 atmosphere, a remarkable current density of 2.24 A cm –2 was achieved at 1.5 V with La 0.6 Ca 0.4 Co 0.2 Fe 0.8 O 3-δ (LCCF64) as the cathode in La 0.8 Sr 0.2 Ga 0.83 Mg 0.17 O 3-δ (LSGM) electrolyte (300 µm) supported electrolysis cells using La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) as the air electrode at 800 °C. Furthermore, symmetrical cells with LCCF64 as the electrodes also show promising electrolysis performance of 1.78 A cm –2 at 1.5 V at 800 °C. In addition, stable cell performance has been achieved on direct CO 2 electrolysis at an applied constant current of 0.5 A cm –2 at 800 °C. The easily removable carbonate intermediate produced during direct CO 2 electrolysis makes LCCF64 a promising regenerable cathode. The outstanding electrocatalytic performance of the LCCF64 cathode is ascribed to the highly active and stable metal/perovskite interfaces that resulted from the in situ exsolved Co/CoFe nanoparticles and the additional oxygen vacancies originated from the Ca 2 Fe 2 O 5 phase synergistically providing active sites for CO 2 adsorption and electrolysis. Here this study offers a novel approach to design catalysts with high performance for direct CO 2 electrolysis.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2019

Targeted Surface Doping with Reversible Local Environment Improves Oxygen Stability at the Electrochemical Interfaces of Nickel-Rich Cathode Materials

Elemental doping represents a prominent strategy to improve interfacial chemistry in battery materials. Manipulating the dopant spatial distribution and understanding the dynamic evolution of the dopants at the atomic scale can inform better design of the doping chemistry for batteries. Herein, we create a targeted hierarchical distribution of Ti 4+ , a popular doping element for oxide cathode materials, in LiNi 0.8 Mn 0.1 Co 0.1 O 2 primary particles. We apply multiscale synchrotron/electron spectroscopy and imaging techniques as well as theoretical calculations to investigate the dynamic evolution of the doping chemical environment. The Ti 4+ dopant is fully incorporated into the TMO6 octahedral coordination and is targeted to be enriched at the surface. Ti 4+ in the TMO 6 octahedral coordination increases the TM–O bond length and reduces the covalency between (Ni, Mn, Co) and O. The excellent reversibility of Ti 4+ chemical environment gives rise to superior oxygen reversibility at the cathode–electrolyte interphase and in the bulk particles, leading to improved stability in capacity, energy, and voltage. Our work directly probes the chemical environment of doping elements and helps rationalize the doping strategy for high-voltage layered cathodes.

25 ENERGY STORAGE↗
DOE OSTI2022

A New Cathode Material for a Li–O 2 Battery Based on Lithium Superoxide

Li–O 2 batteries suffer from large charge overpotentials due to the high charge transfer resistance of Li 2 O 2 discharge products. A potential solution to this problem is the development of LiO 2 -based batteries that possess low charge overpotentials due to the lower charge transfer resistance of LiO 2 . In this report, IrLi nanoparticles were synthesized and implemented for the first time as a LiO 2 battery cathode material. The IrLi nanoparticle synthesis was achieved by a temperature- and time-optimized thermal reaction between a precise ratio of iridium nanoparticles and lithium metal. Li–O 2 batteries employing the IrLi-rGO cathodes were cycled up to 100 cycles at moderate current densities with sustained low cell charge potentials (<3.5 V). Further, various characterization techniques, including SEM, DEMS, TEM, Raman, and titration, were used to demonstrate the LiO 2 discharge product and the absence of Li 2 O 2 . On the basis of first-principles calculations, it was concluded that the formation of crystalline LiO 2 can be stabilized by epitaxial growth on the (111) facets of IrLi nanoparticles present on the cathode surface. These findings demonstrate that, in addition to the previously studied Ir 3 Li intermetallic, the IrLi intermetallic also provides a means by which LiO 2 discharge products can be stabilized and confirms the importance of templating for the formation process.

25 ENERGY STORAGE↗
DOE OSTI2021

1-D NiO nanorods pillared 2-D MnO 2 nanosheets as lithium-free cathode materials for charged-state lithium batteries

Theoretically monolayer MnO 2 sheets have an impressive high capacity of 616 mAh/g, but practically monolayer MnO 2 sheets have poor performances due partially to monolayer restacking. In this paper, we report the preparation of three-dimensional porous NiO nanorod pillared δ-MnO 2 nanosheets as integrated nanoarchitectures as lithium-free cathode materials. The as-synthesized NiO pillared δ-MnO 2 nanosheets have resulted in a moderately high specific capacity of 185 mA h g –1 , with more than 63% capacity retention after 200 cycles. In comparison, 2D MnO 2 nanosheets without NiO pillared structures only achieved a low initial capacity of 137 mA h g –1 , with just 17% capacity retention after 200 cycles. The dramatically improved electrochemical performances could be attributed to high surface areas with excellent porosity which provides more electrochemically active sites and thermodynamically favorable insertion pathways for the lithium ions. Furthermore, our results reveal that insertion of pillars is a promising strategy to explore in order to mitigate the restacking issues and achieve electrochemical performances close to theoretical values for monolayer MnO 2 .

25 ENERGY STORAGE↗