Self-terminating, heterogeneous solid-electrolyte interphase enables reversible Li-ether cointercalation in graphite anodes.

Ether solvents are suitable for formulating solid-electrolyte interphase (SEI)-less ion-solvent cointercalation electrolytes in graphite for Na-ion and K-ion batteries. However, ether-based electrolytes have been historically perceived to cause exfoliation of graphite and cell failure in Li-ion batteries. In this study, we develop strategies to achieve reversible Li-solvent cointercalation in graphite through combining appropriate Li salts and ether solvents. Specifically, we design 1M LiBF4 1,2-dimethoxyethane (G1), which enables natural graphite to deliver ~91% initial Coulombic efficiency and >88% capacity retention after 400 cycles. We captured the spatial distribution of LiF at various length scales and quantified its heterogeneity. The electrolyte shows self-terminated reactivity on graphite edge planes and results in a grainy, fluorinated pseudo-SEI. The molecular origin of the pseudo-SEI is elucidated by ab initio molecular dynamics (AIMD) simulations. The operando synchrotron analyses further demonstrate the reversible and monotonous phase transformation of cointercalated graphite. Our findings demonstrate the feasibility of Li cointercalation chemistry in graphite for extreme-condition batteries. The work also paves the foundation for understanding and modulating the interphase generated by ether electrolytes in a broad range of electrodes and batteries.

Regulating Li Nucleation and Growth Heterogeneities via Near-Surface Lithium-Ion Irrigation for Stable Anode-Less Lithium Metal Batteries.

The inhomogeneous nucleation and growth of Li dendrite combined with the spontaneous side reactions with the electrolytes dramatically challenge the stability and safety of Li metal anode (LMA). Despite tremendous endeavors, current success relies on the use of significant excess of Li to compensate the loss of active Li during cycling. Herein, a near-surface Li+ irrigation strategy is developed to regulate the inhomogeneous Li deposition behavior and suppress the consequent side reactions under limited Li excess condition. The conformal polypyrrole (PPy) coating layer on Cu surface via oxidative chemical vapor deposition technique can induce the migration of Li+ to the interregional space between PPy and Cu, creating a near-surface Li+-rich region to smooth diffusion of ion flux and uniform the deposition. Moreover, as evidenced by multiscale characterizations including synchrotron high-energy X-ray diffraction scanning, a robust N-rich solid-electrolyte interface (SEI) is formed on the PPy skeleton to effectively suppress the undesired SEI formation/dissolution process. Strikingly, stable Li metal cycling performance under a high areal capacity of 10 mAh cm-2 at 2.0 mA cm-2 with merely 0.5 × Li excess is achieved. The findings not only resolve the long-standing poor LMA stability/safety issues, but also deepen the mechanism understanding of Li deposition process.

Fermi level dependence of gas-solid oxygen defect exchange mechanism on TiO2 (110) by first-principles calculations.

In the same way that gases interact with oxide semiconductor surfaces from above, point defects interact from below. Previous experiments have described defect-surface reactions for TiO2(110), but an atomistic picture of the mechanism remains unknown. The present work employs computations by density functional theory of the thermodynamic stabilities of metastable states to elucidate possible reaction pathways for oxygen interstitial atoms at TiO2(110). The simulations uncover unexpected metastable states including dumbbell and split configurations in the surface plane that resemble analogous interstitial species in the deep bulk. Comparison of the energy landscapes involving neutral (unionized) and charged intermediates shows that the Fermi energy EF exerts a strong influence on the identity of the most likely pathway. The largest elementary-step thermodynamic barrier for interstitial injection trends mostly downward by 2.1 eV as EF increases between the valence and conduction band edges, while that for annihilation trends upward by 2.1 eV. Several charged intermediates become stabilized for most values of EF upon receiving conduction band electrons from TiO2, and the behavior of these species governs much of the overall energy landscape.

Bimetallic Nickel/Ruthenium Catalysts Synthesized by Atomic Layer Deposition for Low-Temperature Direct Methanol Solid Oxide Fuel Cells.

Nickel and ruthenium bimetallic catalysts were heterogeneously synthesized via atomic layer deposition (ALD) for use as the anode of direct methanol solid oxide fuel cells (DMSOFCs) operating in a low-temperature range. The presence of highly dispersed ALD Ru islands over a porous Ni mesh was confirmed, and the Ni/ALD Ru anode microstructure was observed. Fuel cell tests were conducted using Ni-only and Ni/ALD Ru anodes with approximately 350 µm thick gadolinium-doped ceria electrolytes and platinum cathodes. The performance of fuel cells was assessed using pure methanol at operating temperatures of 300-400 °C. Micromorphological changes of the anode after cell operation were investigated, and the content of adsorbed carbon on the anode side of the operated samples was measured. The difference in the maximum power density between samples utilizing Ni/ALD Ru and Pt/ALD Ru, the latter being the best catalyst for direct methanol fuel cells, was observed to be less than 7% at 300 °C and 30% at 350 °C. The improved electrochemical activity of the Ni/ALD Ru anode compared to that of the Ni-only anode, along with the reduction of the number of catalytically active sites due to agglomeration of Ni and carbon formation on the Ni surface as compared to Pt, explains this decent performance.

Digital Breast Tomosynthesis in Addition to Conventional 2DMammography Reduces Recall Rates and is CostEffective.

Digital breast tomosynthesis (DBT) as a breast cancer screening modality, through generation of three dimensional images during standard mammographic compression, can reduce interference from breast tissue overlap, increasing conspicuity of invasive cancers while concomitantly reducing falsepositive results. We here conducted a systematic review on previous studies to synthesize the evidence of DBT efficacy, eventually 18 articles being included in the analysis. The most commonly emerging topics were advantages of DBT screening tool in terms of recall rates, cancer detection rates and costeffectiveness, preventing unnecessary burdens on women and the healthcare system. Further research is needed to evaluate the potential impact of DBT on longerterm outcomes, such as interval cancer rates and mortality, to better understand the broader clinical and economic implications of its adoption.

A novel mathematical model to predict the severity of postoperative functional reduction before partial nephrectomy: the importance of calculating resected and ischemic volume.

PURPOSE: Preoperatively predicting postoperative kidney function is an essential step to achieve improved renal function and prevent chronic kidney disease. We introduce a novel formula especially to calculate resected and ischemic volume before partial nephrectomy. We examined whether resected and ischemic volume would have value for predicting postoperative renal function. MATERIALS AND METHODS: We performed a retrospective cohort study in 210 patients who underwent robotic partial nephrectomy between September 2006 and October 2013 at a tertiary cancer care center. Based on abdominopelvic computerized tomography and magnetic resonance imaging we calculated resected and ischemic volume by the novel mathematical formula using integral calculus. We comparatively analyzed resected and ischemic volume, and current nephrometry systems to determine the degree of association and predictability regarding the severity of the postoperative functional reduction. RESULTS: On multivariable analysis resected and ischemic volume showed a superior association with the absolute change in estimated glomerular filtration rate/percent change in estimated glomerular filtration rate (B = 6.5, p = 0.005/B = 6.35, p = 0.009). The ROC AUC revealed accurate predictability of resected and ischemic volume on the stratified event of an absolute change in estimated glomerular filtration rate/event of percent change in estimated glomerular filtration rate compared to 3 representative nephrometry systems. The calibration plot of this model was excellent (close to the 45-degree line) within the whole range of predicted probabilities. CONCLUSIONS: We report a method of preoperatively calculating resected and ischemic volume with a novel formula. This method has superior correlation with the absolute and percent change in estimated glomerular filtration rate compared to current nephrometry systems. The predictive model achieved a strong correlation for the absolute and percent change in estimated glomerular filtration rate.