SEARCH · Search NASA
Results for “composite 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.
Probing Operando Electrochemical Strain Generation in α-NaFeO 2 Composite Cathodes during Cycling of Na-Ion Batteries
The transition metal oxide (TMO) cathodes in Na-ion batteries suffer from low-capacity retention. Chemo-mechanical instabilities lead to the deterioration of the electrochemical performance of TMO cathodes in Li-ion batteries. However, there is not much known about the chemo-mechanical instabilities in the TMO cathodes for Na-ion batteries. Understanding the governing forces behind the interplay between the electrochemical performance and mechanical stability in TMO cathodes is critical for the development of Na-ion batteries. Here, we synchronize the digital image correlation (DIC) technique with electrochemical analysis to capture the real-time deformation behavior of the α-NaFeO 2 cathodes during cycling. When the charge cutoff voltage is 3.6 V, the cathode experiences reversible deformations (except for the first cycle). There is negative strain (shrinkage) generation during Na extraction and positive strain (expansion) generation during the subsequent Na insertion. A detailed analysis of the potential-dependent strain rate evolution points out complicated phase transformations and nonequilibrium conditions in the α-NaFeO 2 cathodes during cycling. When the charge cutoff voltage was increased to 4.2 V, there was a rapid capacity loss and large plastic deformations in the α-NaFeO 2 cathodes. We provide an in-depth discussion about the possible mechanisms behind the chemo-mechanical instabilities in the α-NaFeO 2 . In conclusion, the correlation is critical to develop material-based strategies to mitigate instability mechanisms in TMO cathodes for Na-ion batteries.
Lithium Iron Phosphate Enhances the Performance of High-Areal-Capacity Sulfur Composite Cathodes
Not provided.
A Mo 2 C/Carbon Nanotube Composite Cathode for Lithium–Oxygen Batteries with High Energy Efficiency and Long Cycle Life
Although lithium-oxygen batteries are attracting considerable attention because of potential for extremely high energy density, their practical use has been restricted due to a low energy efficiency and poor cycle life compared to lithium-ion batteries. Here we present a nanostructured cathode based on molybdenum carbide nanoparticles (Mo2C) dispersed on carbon nanotubes (CNT), which dramatically increase the electrical efficiency up to 88 % with a cycle life of more than 100 cycles. We found that the Mo2C nanoparticle catalysts contribute to the formation of a well-dispersed lithium peroxide nanolayers (Li2O2) on the Mo2C/CNTs with large contact area during oxygen reduction reaction (ORR). This Li2O2 structure can be decomposed at low potential upon oxygen evolution reaction (OER) by avoiding the energy loss associated with the decomposition of the typical Li2O2 discharge products.
High-capacity Li2S-graphene oxide composite cathodes with stable cycling performance
Explore the source record for details and available documents.
Long-Term Cr Poisoning Effect on LSCF-GDC Composite Cathodes Sintered at Different Temperatures
Here, the impact of sintering temperature on Cr-poisoning of solid oxide fuel cell (SOFC) cathodes was systematically studied. La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O 3-δ - Ce 0.9 Gd 0.1 O 2-δ symmetric cells were aged at 750°C in synthetic air with the presence of Crofer 22 APU, a common high temperature interconnect, over 200 hours and electrochemical impedance spectroscopy (EIS) was used to determine the degradation process. Both the ohmic resistance (R Ω ) and polarization resistance (R P ) of LSCF-GDC cells, extracted from EIS spectra, for different sintering temperatures increase as a function of aging time. Furthermore, the Cr-related degradation rate increases with decreased cathode sintering temperature. The polarization resistance of cathode sintered at lower temperature (950°C) increases dramatically while aging with the presence of Cr and also significantly decreases the oxygen partial pressure dependence after aging. The degradation rate shows a positive correlation to the concentration of Cr. The results indicate that decreased sintering temperature increases the total surface area, leading to more available sites for Sr-Cr-O nucleation and thus greater Cr degradation.
Performance of Li-SeS2 Solid State Cathodes: Composition and Process Dependence
Explore the source record for details and available documents.
Composite Cathode Architectures for High Performance All-Solid-State Lithium-Sulfur Batteries
Explore the source record for details and available documents.
Nanoscale XANES Tomography of High Voltage Lithium Rich NMC Composite Cathodes
Explore the source record for details and available documents.
High voltage cathode compositions for lithium-ion batteries
A lithium transition metal oxide composition. The composition has the formula Li.sub.a[Li.sub.bNi.sub.cMn.sub.dCo.sub.e]O.sub.2, where a.gtoreq.0.9, b.gtoreq.0, c>0, d>0, e>0, b+c+d+e=1, 1.05.ltoreq.c/d.ltoreq.1.4, 0.05.ltoreq.e.ltoreq.0.30, 0.9.ltoreq.(a+b)/M.ltoreq.1.06, and M=c+d+e. The composition has an O3 type structure.
Cation Aggregation on Extended Defects, Grain Boundaries and Phase Boundaries in LSM/YSZ Composite Cathodes
23rd International Conference on Solid State Ionics (SSI-23), Boston, MA, July 17-22, 2022