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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 289 records · Page 16

Transition Metal Dissolution in Lithium-Ion Cells: A Piece of the Puzzle

Static leaching tests were performed using the chemically delithiated positive electrode materials, LiFePO 4 , LiCoO 2 , LiMn 2 O 4 , LiNiO 2 , and LiNi 0.8 Mn 0.1 Co 0.1 O 2 . Instead of the common electrolyte, which contains LiPF 6 , the solvent consisted of only ethylene carbonate (EC) and ethyl methyl carbonate (EMC), limiting the possible reactions to only those that depend on the solvent. The product liquids from these experiments showed that there were lithium-bearing species in common, such as Li(EC) + and Li(EMC) + . Interestingly, we found evidence of electrolyte degradation products in both the positive-and negative-ion mass spectral results. The positive-ion results showed that the products tended to coordinate to lithium. In conclusion, the negative-ion results showed that most of the products tended to complex with transition metals. It was difficult to discern which positive ion was associated with which negative ion.

25 ENERGY STORAGE↗

Characterization of Tank 9H Dissolution Batches in Support of Tank Closure Cesium Removal (TCCR) 1A Batch 1 Preparations

Savannah River Remediation (SRR) is currently preparing the first batch of material to be processed through the Tank Closure Cesium Removal (TCCR) 1A system. The feed for TCCR 1A will consist of dissolved saltcake from Tank 9H. Two batches of salt (Batch 1A and Batch 1B) have been dissolved in Tank 9H and subsequently transferred to Tank 10H to prepare Batch 1 for TCCR 1A. Savannah River National Laboratory (SRNL) received samples from each batch of dissolved salt prior to transfer for characterization. SRNL received both a surface and a variable depth sample from Batches 1A and 1B. In both cases no solids were observed in the surface sample, but were observed in the depth sample. For Batch 1A the variable depth sample was only slightly cloudy, while for Batch 1B the variable depth sample contained a significant amount (10.14 wt%) of solids. The solids were determined to be primarily aluminum containing phases, with only a small fraction (0.22 wt%) being sludge solids. In general, the samples from Batch 1A were more concentrated salt solutions than Batch 1B, with sodium concentrations of 8.53 and 8.57 M for the surface and filtered depth samples in Batch 1A, respectively. The sodium concentrations in Batch 1B samples ranged from 4.27 M for the surface sample to 7.57 M for the depth sample filtrate, indicating some stratification within the tank. The 137 Cs activity as well as the total Cs concentration in the filtered Batch 1A depth sample were approximately double the activity and concentration measured in the filtrate from the Batch 1B depth sample. The total Cs concentration in the Batch 1A depth sample filtrate was 22.4 mg/L, while for the Batch 1B depth sample filtrate the total Cs concentration was calculated to be 12.0 mg/L. These Cs concentrations are significantly higher than was measured in Batches 1-3 from Tank 10H dissolved saltcake which was previously processed through the original TCCR unit.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Characterization of Tank 9H Salt Dissolution Batch 2A in Support of Tank Closure Cesium Removal (TCCR) 1A Batch 2 Preparations

Savannah River Remediation (SRR) is currently preparing the second batch of material to be processed through the Tank Closure Cesium Removal (TCCR) 1A system. The feed for TCCR 1A consists of dissolved saltcake from Tank 9H. The first batch of salt to make up Batch 2 (Batch 2A) has been dissolved in Tank 9H and will later be transferred to Tank 10H. Savannah River National Laboratory (SRNL) received samples from the batch of dissolved salt for characterization.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Characterization of Tank 9H Salt Dissolution Batch 2B in Support of Tank Closure Cesium Removal (TCCR) 1A Batch 2 Preparations

Savannah River Mission Completion (SRMC) is currently preparing the second batch of material to be processed through the Tank Closure Cesium Removal (TCCR) 1A system. The feed for TCCR 1A consists of dissolved saltcake from Tank 9H. The second batch of salt to make up processing Batch 2 (Batch 2B) has recently been dissolved in Tank 9H and transferred to Tank 10H where it was composited with the first part of the batch (Batch 2A) in preparation for processing through the TCCR 1A unit. Savannah River National Laboratory (SRNL) received samples from the recent batch (2B) of dissolved salt for characterization. Two samples from Batch 2B were received for characterization, a surface sample and a variable depth sample (VDS). Neither sample contained significant solids, although the VDS appeared slightly cloudy as compared to the surface sample. The sodium concentrations of both the surface and VDS filtrate samples were approximately 5.8 M, and the 137 Cs activity was 9.8E+07 dpm/mL in the surface sample and 9.5E+07 dpm/mL in the VDS. The total Cs concentrations were 2.5 mg/L and 2.4 mg/L in the surface sample and VDS, respectively, using the gamma activity and the Cs isotopic ratios determined by ICP-MS. The alpha activity was below the detection limit in both samples. Nitrate was the dominant anion present, and the samples were primarily concentrated sodium nitrate solutions with hydroxide, nitrite, and carbonate present at 0.1 – 0.2 M. In general, the Batch 2B samples were more dilute than the previously characterized Batch 2A samples.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Lab Scale Mercury Dissolution Testing

Researchers at the Savannah River National Laboratory were requested by Savannah River Mission Completion to perform laboratory testing and modeling designed to understand why the Defense Waste Processing Facility (DWPF) is not collecting elemental mercury (Hg 0 ) despite long boiling times designed to recover Hg 0 . In response to a Technical Task Request, a Task Technical and Quality Assurance Plan was written and approved to authorize this work.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Recent advances in acid-free dissolution and separation of rare earth elements from the magnet waste

The availability of REEs is limiting the successful deployment of some environmentally friendly and energy-efficient technologies. In 2019, the U.S. generated more than 15.25 billion pounds of e-waste. Only ~15% of it was handled, leaving ~13 billion pounds of e-waste as potential pollutants. Of the 15% collected, the lack of robust technology limited REE recovery for re-use. Key factors that drive the recycling of permanent magnets based on rare earth elements (REEs) and the results of our research on magnet recycling will be discussed, with emphasis on neodymium and samarium-based rare earth permanent magnets.

36 MATERIALS SCIENCE↗

Bromine Assisted MnO 2 Dissolution Chemistry: Toward a Hybrid Flow Battery with Energy Density of over 300 Wh L −1

Abstract Mn 2+ /Mn 3+ redox pair has been considered as a promising cathode for high energy density batteries, due to its attractive features of high redox potential, solubility and outstanding kinetics. However, the disproportionation side reaction of Mn 3+ , which results in accumulation of “dead” MnO 2 limits its reversibility and further energy density. Herein, a novel catholyte based on mixture of Mn 2+ and Br − was proposed for flow batteries with high energy density and long cycle life. In the design, the “dead” MnO 2 can be fully discharged via Br − by a chemical‐electrochemical reaction. Coupled with Cd/Cd 2+ as anode, the assembled Bromine‐Manganese flow battery (BMFB) demonstrates a high energy efficiency of 76 % at 80 mA cm −2 with energy density of 360 Wh L −1 . The battery assembled with silicotungstic acid as anode could continuously run for over 2000 cycles at 80 mA cm −2 . With high power density, energy density and durability, the BMFB shows great potential for large‐scale energy storage.

Chemistry↗