Search NASA⌕ Search

SEARCH · Search NASA

Results for “NMC Cathode”

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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Reciprocal Ternary Molten Salts Enable the Direct Upcycling of Spent Lithium‐Nickel‐Manganese‐Cobalt Oxide (NMC) Mixtures to Make NMC 622

Cathode active material is the most valuable component of spent lithium‐ion batteries, accounting for ≈30% of their overall value. Direct recycling of cathode materials involves recovering, regenerating, and reusing them without breaking down their chemical structure. This approach maximizes the added value of the cathode compound and reduces manufacturing costs by avoiding the need for virgin material production. However, one key challenge in scaling direct recycling from lab to industry is the requirement for highly purified cathode materials, contrasting with the low purity of black mass generated from battery shredding. No efficient separation process currently exists to isolate different lithium‐nickel‐manganese‐cobalt oxides (NMCs) from each other. Thus, direct recycling technologies that can operate with mixtures of multiple NMC stoichiometries will be best‐suited for industrial adoption. This study explores the direct recycling of NMC mixtures into NMC 622 using a “reciprocal ternary molten salts (RTMS)” system. Ionothermal relithiation and upcycling within the RTMS system successfully restore the layered structure, lithium content, and electrochemical performance of degraded NMCs, yielding results comparable to pristine NMC 622 (P‐NMC 622).

25 ENERGY STORAGE↗
DOE OSTI2024

Stabilizing Nickel‐Rich Cathodes in Aqueous Process through Nanocellulose as Water Barrier

Nickel-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NMC 811) cathode offers high voltage and high specific capacity, making it promising for high energy density batteries. However, large-scale manufacturing of aqueous-processed NMC 811 electrodes remains challenging due to proton exchange causing material decomposition and capacity loss. This work addresses this issue by constructing an in situ nanocellulose protective layer for NMC 811 particles via electrostatic interactions during the slurry preparation. For the first time, the interatomic spacing between inter-chains of nanocellulose is measured through wide-angle X-ray scattering and demonstrate the ability to effectively confine interlayer water using atomistic simulations. Moreover, this nanocellulose coverage simultaneously minimizes Li + surface segregation and mitigates water infiltration. Owing to less material decomposition during the aqueous processing, nanocellulose-protected NMC electrodes exhibit higher initial coulombic efficiency (83% vs 62% at 0.1C) and capacity (133 vs 59 mAh g −1 at 6C) than unprotected electrodes. Additionally, optimized aqueous-processed NMC electrodes offer comparable or even superior electrochemical properties compared to the electrodes fabricated using the conventional toxic organic solvent, N-methyl-2-pyrrolidone. Consequently, the developed approach enables affordable, sustainable aqueous processing for Nickel-rich NMC 811 cathodes with excellent electrochemical performances.

25 ENERGY STORAGE↗
DOE OSTI2023

Direct recycling of spent nickel-rich cathodes in reciprocal ternary molten salts

Lithium-ion batteries (LIBs) have revolutionized portable electronics and electric vehicles (EVs), but the growing accumulation of end-of-life (EOL) batteries poses environmental challenges. Recycling high-value cathodes from EOL LIBs can minimize waste and reduce the need for mining critical minerals. Here, this study focuses on the direct recycling of Ni-rich cathodes, particularly lithium-manganese-cobalt-oxide (NMC) 622 in a “reciprocal ternary molten salts (RTMS)" system. The ionothermal relithiation in the RTMS system successfully restores the layered structure, lithium content, and electrochemical performance of the NMC 622 cathode, comparable to the pristine material. The cost analysis reveals that cathode regeneration through ionothermal relithiation is more economical than virgin production or conventional recycling methods.

25 ENERGY STORAGE↗
DOE OSTI2023

Influence of Single-Crystalline Morphology on the Electrochemical Behavior of High-Nickel Layered Oxide Cathodes

High-Nickel layered oxides are being pursued for their high specific capacities. With increasing nickel content, the layered oxides also suffer from structural and morphological instabilities, which degrade the electrochemical performance. Single-crystalline morphology presents an attractive solution to these problems, simultaneously reducing surface area available for parasitic reactions and preventing electrolyte penetration into the bulk with the removal of grain boundaries. Single-crystal cathodes have already shown promising results with NMC composition cathodes, but there are still gaps in the fundamental understanding of how single-crystalline morphology alters electrochemical behavior. We attempt to fill some of these gaps by studying in detail the electrochemical operation of polycrystalline and single-crystalline LiNiO 2 (LNO). Single-crystal LNO is prepared through a molten salt method yielding high-quality, distinct crystals with comparable lattice chemistry to polycrystalline LNO. The single-crystal LNO achieves far greater stability during long-term cycling, reaching 500 cycles with 82.5% capacity retention. Interestingly, the single-crystalline LNO also displays superior rate performance, delivering 157 mA h g −1 at 10C discharge rate. Investigation of the phase evolution behavior during cycling strongly suggests that the absence of grain boundaries in single-crystalline LNO is responsible for the superior performance.

25 ENERGY STORAGE↗
DOE OSTI2022

Locking oxygen in lattice: A quantifiable comparison of gas generation in polycrystalline and single crystal Ni-rich cathodes

High-energy Ni-rich NMC (LiNi x Mn y Co 1-x-y O 2 , x ≥ 0.6) is a very promising cathode material in Li-ion batteries but the gas generation during cycling is a significant safety concern and becomes the major roadblock of the large-scale commercialization of Ni-rich NMC cathode materials. Micron-sized single crystal Ni-rich NMC has a potential to address the common issues that polycrystals have. However, it is unknown if gassing issue will be mitigated or even eliminated by using single crystals, not mentioning a quantifiable understanding of gas generation from single crystals and polycrystals. This work takes LiNi 0.76 Mn 0.14 Co 0.1 O 2 (NMC76) as a model material to study the mechanism of gas generation from single crystal and polycrystalline NMC by using both coin cells and pouch cells, which provides different conclusions on the generated gases, highlighting the importance of using relevant testing conditions for fundamental diagnostic study on battery materials. Further, the information from single crystal NMC also provides critical insights from material perspective to enhance the safety attributes of Ni-rich NMC cathodes.

25 ENERGY STORAGE↗
DOE OSTI2020

Facile and scalable dry surface doping technique to enhance the electrochemical performance of LiNi 0.64 Mn 0.2 Co 0.16 O 2 cathode materials

Lithium nickel manganese cobalt oxide (NMC) is one of the dominant cathode materials in lithium-ion batteries. In this study a simple, efficient and scalable surface doping technique is successfully demonstrated, which can be readily used in mass production of cathode materials. For the first time neodymium oxide (Nd 2 O 3 ) has been employed as the surface doping agent. The Nd-doped NMC shows greatly improved cycling and rate performance, and the enhanced cycling stability has been demonstrated in full pouch cells, with a 17.5% increase in capacity retention after 300 cycles. Fewer cracks have been observed in the doped NMC after cycling, and in situ X-ray diffraction reveals the suppressed lattice collapse by Nd doping. Greatly suppressed surface phase change has been confirmed by HR-TEM and EELS. The result suggests great promise in using this dry doping technique to enhance the electrochemical performance of NMC cathodes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Structure–Property Relationships of Recycled Lithium-Ion Battery Cathodes: Microstructure Optimization Using Virtual Materials Testing

The increasing demand for sustainable battery technologies requires effective recycling strategies for end-of-life lithium-ion battery cathodes. In this study, virtual materials testing, a well-established framework for modeling conventionally manufactured NMC-based cathodes, is applied to partially recycled cathodes. To this end, virtual cathodes consisting of mixtures of pristine and recycled NMC particles are utilized to systematically analyze structure–property relationships depending on mixing ratios and different spatial arrangement strategies. For this purpose, a stochastic 3D model is developed that is capable of generating virtual cathodes with arbitrary volume fractions of active materials and mixing ratios of pristine and recycled NMC particles. Particularly, the stochastic 3D model can mimic the different size distributions of pristine and recycled particles that are observed in image data. Additionally, the model allows the structuring of pristine and recycled NMC either uniformly mixed or layer-wise arranged, mimicking single- and dual-layer cathodes. Subsequently, a systematic computational analysis is conducted to assess the influence of increasing active material ratios of recycled particles, ranging from 0 % to 100 %, while maintaining a constant overall active material volume fraction. The impact of particle mixing on cathode performance is evaluated by examining transport-relevant geometrical descriptors and effective properties, such as geodesic tortuosity, specific surface area, and tortuosity factor.

25 ENERGY STORAGE↗
DOE OSTI2022

Extreme fast charge aging: Effect of electrode loading and NMC composition on inhomogeneous degradation in graphite bulk and electrode/electrolyte interface

Empowering extreme fast charging (XFC) requires a comprehensive understanding of its application with advanced anode and cathode materials in lithium-ion batteries. No report exists for the full extent of limitations for the anode with crosstalk effect from paired cathode as well as Li plating due to electrode loading under XFC. In this study, a combination of cell testing and multiple length characterization is used to investigate XFC aging mechanism in cells with a low loading of 1.5 mAh cm -2 and high loading of 2.5 mAh cm -2 for graphite (Gr)/Ni-rich LiNi x Mn y Co 1-x-y O 2 (NMCs). Operando XRD mappings show 1.5 mAh cm -2 loadings result in higher strain in graphite for all three cathode types. Among the three NMC cathodes, the graphite from NMC532 and NMC811 cells show comparable strain. Scanning electron microscopy (SEM) images show distinct differences between 6-C-charged anodes in two loadings. Significantly increased electrode thickness can be seen due to more damage in the graphite bulk and accumulation of the electrolyte decomposition products in electrode pores. X-ray photoelectron spectroscopy (XPS) reveals both cathode chemistry and Li plating influence the non-uniform SEI composition on graphite surface. We report higher Ni content in NMC811 promotes the higher levels of salt decomposition on the SEI and formation of higher mass of electrolyte aging products.

25 ENERGY STORAGE↗
DOE OSTI2021

Self-Stabilized LiNi 0.8 Mn 0.1 Co 0.1 O 2 in thiophosphate-based all-solid-state batteries through extra LiOH

Nickle-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NMC 811) cathode material exhibits engaging properties in high energy density and low cost, making it great potential for the next generation high-energy all-solid-state lithium batteries (ASSLBs). However, NMC 811 suffers from severe surface electrochemical, chemical, and voltage incompatibility towards solid-state electrolytes (SSE), especially thiophosphate-based electrolytes like Li 6 PS 5 Cl. Although diverse coating methods have been made to overcome this issue, they are typically cumbersome and expensive. A coating strategy that satisfied all the requirements of cost-efficiency, stability, uniformity, scalability, and easy-achieving is still challenging. Here, we developed a LiOH-based surface stabilization strategy that provides a ~10 nm stable permeable layer on NMC 811. After one-step sintering of NMC 811 precursor mixed with LiOH, which is commonly used for NMC 811 lithiation process, excessive LiOH simultaneously distributes on NMC 811 particles. Unlike other reported methods, this coating method can be easily controlled and fabricated without additional complicated processes. By simply controlling the thickness of LiOH layer, which protects the Li 6 PS 5 Cl solid electrolyte materials from being oxidized, optimized cycling stability can be obtained for 600 cycles with capacity of 130 mAh g – 1 on average at a wide electrochemical window of 2.50–4.20 V (vs. Li-In).

25 ENERGY STORAGE↗
DOE OSTI2020

Direct Observation of Defect‐Aided Structural Evolution in a Nickel‐Rich Layered Cathode

Abstract Ni‐rich LiNi 1− x − y Mn x Co y O 2 (NMC) layered compounds are the dominant cathode for lithium ion batteries. The role of crystallographic defects on structure evolution and performance degradation during electrochemical cycling is not yet fully understood. Here, we investigated the structural evolution of a Ni‐rich NMC cathode in a solid‐state cell by in situ transmission electron microscopy. Antiphase boundary (APB) and twin boundary (TB) separating layered phases played an important role on phase change. Upon Li depletion, the APB extended across the layered structure, while Li/transition metal (TM) ion mixing in the layered phases was detected to induce the rock‐salt phase formation along the coherent TB. According to DFT calculations, Li/TM mixing and phase transition were aided by the low diffusion barriers of TM ions at planar defects. This work reveals the dynamical scenario of secondary phase evolution, helping unveil the origin of performance fading in Ni‐rich NMC.

Li, Shuang↗
DOE OSTI2022

The impact of residual solvent on catholyte performance in solid-state batteries

All-solid-state batteries (ASSBs) are attractive due to their safety, use of the Li metal anode, high energy density, and innovative processing routes. However, high interfacial resistance, especially on the cathode side, is one of the major challenges for commercialization of ASSBs. Catholyte, either a liquid or solid, is added to lower the cathode/electrolyte interfacial resistance. In this study, we find that residual N-methylpyrrolidone solvent remaining in a PVDF/LiTFSI solid polymer catholyte after incomplete drying can dramatically lower the interfacial resistance between the Li 6.25 Al 0.25 La 3 Zr 2 O 12 electrolyte and LiNi 1/3 Mn 1/3 Co 1/3 O 2 cathode-active material. Cells with varying amounts of residual solvent are compared to optimize the residual solvent loading. With moderate residual solvent, the discharge capacity reaches 142 mA h g -1 when cycled at 25 °C and 0.5 C and the capacity retention is 60.5% after 125 cycles. Discharge capacity retention is improved at -10 °C. The conductivity of the free-standing PVDF/LiTFSI film, mimicking the PVDF/LiTFSI catholyte, verifies the role of residual NMP in the cathode. Finally, this study demonstrates the possibility of widely differing results for ASSBs when the cathode is not completely dried. Also, it provides a hint for a potential method to lower the cathode/electrolyte interfacial resistance.

25 ENERGY STORAGE↗
DOE OSTI2021

Surface Modification of Nickel-Rich Cathode Materials by Ionically Conductive Materials at Room Temperature

Nickel-rich cathode materials (LiNi x Mn y Co 1-x-y O 2 , NMC) are promising to push the limits of lithium-ion batteries to higher energy density. This approach is favored in practical applications including electric vehicles and aviation transportation. However, the instability of the NMC at charged state results in safety concerns and poor cycling stability. Surface coating is a practical and effective strategy to address this. Cubic Li7La3Zr2O12 (LLZO) is an ideal coating material regarding the low electron transfer rate and high Li+ conductivity. Thus, a LLZO coating layer can suppress the parasitic reactions in the electrode/electrolyte interface without deteriorating the lithium migration. However, high-temperature calcination seems to inevitably create the chemical couplings between NMC and LLZO, leading to the interdiffusion and degradation of NMC and LLZO crystal structures. This work presents a simple mechanochemical method to effectively coat LLZO on the NMC particle surface. Furthermore, the coated cathode demonstrates superior electrochemical performance compared with the pristine NMC cathode.

25 ENERGY STORAGE↗
DOE OSTI2022

Resolving Charge Distribution for Compositionally Heterogeneous Battery Cathode Materials

The isostructural nature of Li-layered cathodes allows for accommodating multiple transition metals (TMs). However, little is known about how the local TM stoichiometry influences the charging behavior of battery particles thus impacting battery performance. In this work, we develop heterogeneous compositional distributions in polycrystalline LiNi 1–x–y Mn x Co y O 2 (NMC) particles to investigate the interplay between local stoichiometry and charge distribution. These NMC particles exhibit a broad, continuous distribution of local Ni/Mn/Co stoichiometry, which does not compromise the global layeredness. The local Mn and Ni concentrations in individual NMC particles are positively and negatively correlated with the electrochemically induced Ni oxidation, respectively, whereas the Co concentration does not impose a clear effect on the Ni oxidation. The resulting material delivers excellent reversible capacity, rate capability, and cycle life at high operating voltages. Engineering Ni/Mn/Co distribution in NMC particles may provide a path toward controlling the charge distribution and thus chemomechanical properties of polycrystalline battery particles.

25 ENERGY STORAGE↗
DOE OSTI2025

Operando neutron imaging-guided gradient design of Li-ion solid conductor for high-mass-loading cathodes

High-mass-loading cathodes are crucial for achieving high energy density in all-solid-state batteries from the lab scale to industry. However, as mass-loading increases, electrochemical performance is significantly compromised due to sluggish kinetics. In this work, operando neutron imaging is deployed on a high-mass-loading NMC 811 cathode of 33 mg/cm 2 (5.0 mAh/cm 2 ) and directly visualizes the lithiation prioritization of the cathode active material (CAM) from the solid electrolyte membrane side to the current collector side. In addition to the tortuosity, another key limitation on ion transfer in the cathode arises from the mismatch between the uniform distribution of the solid electrolyte (catholyte) in the conventional composite cathode and the non-uniform Li + flux generated by the faradaic reaction of CAMs. Therefore, we engineer a gradient in the catholyte concentration to match the Li + flux distribution as a means of eliminating the ion transfer obstacle. This approach demonstrates enhanced rate performance, even with high-mass-loading cathodes. A LiCoO 2 composite cathode with 100 mg/cm 2 high-mass-loading exhibits an areal capacity of 10.4 mAh/cm 2 at a current density of 2.25 mA/cm 2 . This work provides insight into the ion-transport limitation in thick cathodes and demonstrates an effective gradient design to overcome the kinetic barrier and achieve high battery performance.

Batteries↗
DOE OSTI2023

3D–Integrated, Multi–Functional Carbon Fibers for Stable, High–Areal–Capacity Batteries

Increasing lithium-ion batteries' (LIBs) electrode areal capacity can boost energy density and lower manufacturing costs, but faces challenges in manufacturing, rate performance, and cycling stability. A conductive framework made of commercial micro-sized carbon fibers (Cfs) is presented that serves as a host for both the LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC 532) cathode and Cfs anode. The Cf framework has multiple functions that offer high electronic conductivity (270 mS cm –1 ), low tortuosity (1.7), low Li + diffusion resistance (22 Ω), and high thermal conductivity (200 W mK –1 ). Additionally, the Cf-integrated electrodes can have an extremely high mass loading of NMC 532 (70 mg cm –2 ) with a theoretical capacity of 14 mAh cm –2 . Thus, the practical full cells assembled with the Cfs-enabled electrodes exhibit an initial areal capacity of 4.1 mAh cm –2 and capacity retention of 90.4% at 500 cycles at a cycling rate of C/3, 1.5 mA cm –2 . Data collected from the operando isothermal microcalorimetry suggest that full cells utilizing the Cf anode experience less heat release from side reactions compared to cells utilizing a conventional graphite anode. Finally, this present approach is scalable and cost-effective and can fabricate practical LIBs that boast high areal capacity, rate performance, and a lengthy cycling lifetime.

25 ENERGY STORAGE↗
DOE OSTI2023

Fast Charge Induced Phase Evolution and Element Contribution of Nickel-Rich Layered Cathode for Lithium-Ion Batteries

In nickel-rich layered cathode materials, three transition metals (TM = Ni, Co and Mn) play critical roles in Li storage performance. However, rate-dependent phase evolution and elemental contribution of nickel-rich cathode materials are not well understood, but very important for further design and development of these cathodes in high-power applications. Here, the rate-dependent phase evolution and elemental contribution of LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532) cathode are investigated thoroughly by using time-resolved synchrotron-based in situ X-ray diffraction and absorption techniques. The increase of Ni content in NMC532 has been found to be the main cause of the complex structural changes, resulting in distortion of TM-O 6 octahedron and strong static vibration between TM and O coordination. It is revealed that the fast charge (10C and 30C) of NMC532 leads to intermediate Li-poor phases, shrinking of H2 phase region, and prolonged O1 phase. During high-rate charging, Co is oxidized easily in low voltage region, while Ni mainly dominates charge compensation in high voltage region. It is found that delithiation-induced local structure distortion transfers from Ni to Co sites in fast kinetic process. In conclusion, these findings provide in-depth understanding for the fast charge behavior of Ni-rich layered cathode materials and help to guide further development of advanced high-power lithium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2023

Long-life lithium-ion batteries realized by low-Ni, Co-free cathode chemistry

The increasing demand for lithium-ion battery-powered electric vehicles (EVs) has led to a surge in recent prices of strategic battery materials such as cobalt (Co) and nickel (Ni). While all EV makers are eager to eliminate Co usage, Ni has rapidly become another ‘pain point’ for the industry, as its price is nearing half that of Co. The sustainability issue facing both Ni and Co puts forward a grand materials challenge, that is, to reduce Ni content and eliminate Co while maintaining high specific energy and stability. Here in this work, a complex concentrated doping strategy is used to eliminate Co in a commercial NMC-532 cathode. The LiNi 0.5 Mn 0.43 Ti 0.02 Mg 0.02 Nb 0.01 Mo 0.02 O 2 cathode shows potential cost advantage with relatively high specific energy and significantly improved overall performance (~95% capacity retained after 1,000 cycles in pouch-type cells, 2.8–4.3 V vs graphite, at 1 C, 1.5 mA cm -2 ). Combining X-ray techniques and electron microscopy, we uncover the origins of the superior stability.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Computational modeling of coupled mechanical damage and electrochemistry in ternary oxide composite electrodes

Performance degradation of ternary layered oxide cathodes largely originates from their loss of structural integrity in cyclic usage. Mechanical damage, such as intergranular fracture of the active particles, is not only a mechanical cleavage process but also interferes with electrochemical kinetics such as infiltration of liquid electrolyte, surface corrosion of the constituent primary particles, and may eventually isolate the primary grains from the electron conducting network. Here, in this work, we develop a computational framework that integrates electrochemistry of a LiNi x Mn y Co 1−x−y O 2 (NMC) composite cathode with mechanical damage of the active particles. To fully examine the intricate chemomechanical behavior of the electrode, we evaluate the effects of the anisotropic material properties, the influence of mechanical potential on Li transport, and the concurrent intergranular fracture and electrolyte penetration along the grain boundaries upon multiple cycles. Electrolyte infiltration benefits capacity retention but aggravates further mechanical damage by corrosion. Structural failure mostly occurs in the first charging due to the anisotropic mechanical strain between the primary grains, while the resulting damage remains stable in the later few cycles. The results are consistent with experimental observations and the integration of electrochemistry and mechanical failure enables a step further understanding of the complex mechanism of battery degradation.

Battery degradation↗