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Results for “lithium”
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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Deciphering pitting behavior of lithium metal anodes in lithium sulfur batteries
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Voltammetry measurements in lithium chloride-lithium oxide (LiCl–Li 2 O) salt: An evaluation of working electrode materials
Instrumentation to provide process monitoring (PM) and safeguards for the oxide reduction (OR) step in the electrochemical processing of used oxide nuclear fuel is necessary to ensure equipment is operated as declared. Cyclic voltammetry (CV) has been proposed for real-time monitoring of the operation of an OR process for safeguards purposes. In this study, different materials including 316 stainless steel (SS), tantalum (Ta), molybdenum (Mo), tungsten (W), platinum (Pt), and iridium (Ir) were evaluated as potential working electrode (WE) materials based on their chemical inertness, corrosion resistance, and sensitivity in detecting Li 2 O and other chloride salts in the OR electrolyte. Of the electrodes evaluated, 316 SS, Ir, and Pt all performed reasonably well in the LiCl-Li 2 O electrolyte. Here, stainless steel was operated in the cathodic potential and had reasonable corrosion resistance and is relatively inexpensive. Iridium could be operated in both the cathodic and anodic potentials and was the most corrosion resistant of those evaluated. Platinum is limited to the anodic potential range, had reasonable corrosion resistance, and was the most sensitive to Li 2 O concentrations in the salt. In the development of a stand-alone safeguards instrumentation, our recommendation is a CV sensor fitted with both Ir and Pt WEs. The results in this study may also be helpful for anode material selection in other electrometallurgy industries, such as molten salt electrolysis.
High-Efficiency Lithium-Metal Anode Enabled by Liquefied Gas Electrolytes
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Tracking inhomogeneity in high-capacity lithium iron phosphate batteries
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Stable lithium electrodeposition in salt-reinforced electrolytes
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High-rate lithium–sulfur batteries enabled by hierarchical porous carbons synthesized via ice templation
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Heat transfer enhancement in a lithium-ion cell through improved material-level thermal transport
We report that while Li-ion cells offer excellent electrochemical performance for several applications including electric vehicles, they also exhibit poor thermal transport characteristics, resulting in reduced performance, overheating and thermal runaway. Inadequate heat removal from Li-ion cells originates from poor thermal conductivity within the cell. This paper identifies the rate-limiting material-level process that dominates overall thermal conduction in a Li-ion cell. Results indicate that thermal characteristics of a Li-ion cell are largely dominated by heat transfer across the cathode-separator interface rather than heat transfer through the materials themselves. This interfacial thermal resistance contributes around 88% of total thermal resistance in the cell. Measured value of interfacial resistance is close to that obtained from theoretical models that account for weak adhesion and large acoustic mismatch between cathode and separator. Further, to address this problem, an amine-based chemical bridging of the interface is carried out. This is shown to result in in four-times lower interfacial thermal resistance without deterioration in electrochemical performance, thereby increasing effective thermal conductivity by three-fold. This improvement is expected to reduce peak temperature rise during operation by 60%. Finally, by identifying and addressing the material-level root cause of poor thermal transport in Li-ion cells, this work may contribute towards improved thermal performance of Li-ion cells.
A facile cathode design combining Ni-rich layered oxides with Li-rich layered oxides for lithium-ion batteries
A facile synthesis method was developed to prepare xLi 2 MnO 3 ·(1-x)LiNi 0.7 Co 0.15 Mn 0.15 O 2 (x = 0, 0.03, 0.07, 0.10, 0.20, and 0.30 as molar ratio) cathode materials, combining the advantages of high specific capacity from Ni-rich layered phase and surface chemical stability from Li-rich layered phase. X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM) and electrochemical charge/discharge performance confirm the formation of a Li-rich layered phase with C2/m symmetry. Most importantly, high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) reveals a spatial relationship that Li-rich nano-domain islands are integrated into a conventional Ni-rich layered matrix (R$\bar{3}$m). This is the first time that Li-rich phase has been directly observed inside a particle at the nano-scale, when the overall composition of layered compounds (Li 1+δ Ni x Mn y M 1-x-y-δ O 2 , M refers to transition metal elements) is Ni-rich (x > 0.5) rather than Mn-rich (y > 0.5). Remarkably, xLi 2 MnO 3 ·(1-x)LiNi 0.7 Co 0.15 Mn 0.15 O 2 cathode with optimized x value shows superior electrochemical performance at C/3, i.e., 170 mA h g -1 with 90.3 % of capacity retention after 400 cycles at 25 °C and 164 mA h g -1 with 81.3 % capacity retention after 200 cycles at 55 °C.