ABSTRACT
Developing rechargeable batteries with high power delivery at low temperatures (LT) below 0 °C is significant for cold-climate applications. Initial anode-free sodium metal batteries (AFSMBs) promise high LT performances because of the low de-solvation energy and smaller Stokes radius of Na+, nondiffusion-limited plating/stripping electrochemistry, and maximized energy density. However, the severe reduction in electrolyte ionic conductivity and formation of unstable solid electrolyte interphase (SEI) hinder their practical applications at LT. In this study, a 2-methyltetrahydrofuran-based dilute electrolyte is designed to concurrently achieve an anion-coordinated solvation structure and impressive ionic conductivity of 3.58 mS cm-1 at -40 °C. The dominant aggregate solvates enable the formation of highly efficient and LT-resistant Na+ hopping channels in the electrolyte. Moreover, the methyl-regulated electronic structure in 2-methyltetrahydrofuran induces gradient decomposition toward an inorganic-organic bilayer SEI with high Na+ mobility, composition homogeneity, and mechanical robustness. As such, a record-high Coulombic efficiency beyond 99.9% is achieved even at -40 °C. The as-constructed AFSMBs sustain 300 cycles with 80% capacity maintained, and a 0.5-Ah level pouch cell delivers 85% capacity over 180 cycles at -25 °C. This study affords new insights into electrolyte formulation for fast ionic conduction and superior Na reversibility at ultralow temperatures.
ABSTRACT
INTRODUCTION: Lymphadenectomy is a cornerstone in the surgical management of resectable primary lung cancer. However, its prognostic significance in early-stage metachronous second primary lung cancer (MSPLC) remains poorly understood. This retrospective study aimed to evaluate the prognostic impact of lymphadenectomy in these patients using data from the Surveillance, Epidemiology, and End Results (SEER) Database. METHODS: A retrospective cohort study was conducted using data from the SEER Database for patients surgically treated for stage I MSPLC between 2004 and 2015. Propensity score-matching was employed to create comparable cohorts, and the Cox proportional hazards model was utilized to estimate the hazard ratio (HR) for overall survival after lymphadenectomy compared to non-lymphadenectomy. Survival analysis was performed using Kaplan-Meier curves and the log-rank test. RESULTS: Among 920 identified patients with MSPLC, 574 (62.4%) underwent lymphadenectomy. Propensity score-matching yielded 255 patients in both the lymphadenectomy and non-lymphadenectomy groups. Over a median follow-up of 38 months, the 5-year overall survival probability after a diagnosis of MSPLC was 58.7% in the lymphadenectomy group and 43.9% in the non-lymphadenectomy group (HR: 0.76; 95% confidence interval 0.64-0.90; p = 0.002). CONCLUSION: In this population-based study, lymphadenectomy is associated with prolonged overall survival in patients with stage I MSPLC. These findings suggest the potential benefit of incorporating lymphadenectomy into the surgical management of MSPLC, providing valuable guidance for thoracic surgeons in clinical decision-making.
Subject(s)
Lung Neoplasms , Lymph Node Excision , Neoplasms, Second Primary , SEER Program , Humans , Male , Female , Lymph Node Excision/mortality , Lymph Node Excision/methods , Retrospective Studies , Lung Neoplasms/surgery , Lung Neoplasms/mortality , Lung Neoplasms/pathology , Middle Aged , Aged , Neoplasms, Second Primary/surgery , Neoplasms, Second Primary/mortality , Neoplasms, Second Primary/pathology , Neoplasm Staging , Prognosis , Propensity Score , Kaplan-Meier Estimate , Survival RateABSTRACT
The reversible and durable operation of sodium metal batteries at low temperatures (LT) is essential for cold-climate applications but is plagued by dendritic Na plating and unstable solid-electrolyte interphase (SEI). Current Coulombic efficiencies of sodium plating/stripping at LT fall far below 99.9%, representing a significant performance gap yet to be filled. Here, the solvation structure of the conventional 1 m NaPF6 in diglyme electrolyte by facile cyclic ether (1,3-dioxolane, DOL) dilution is efficiently reconfigured. DOL diluents help shield the Na+-PF6 - Coulombic interaction and intermolecular forces of diglyme, leading to anomalously high Na+-ion conductivity. Besides, DOL participates in the solvation sheath and weakens the chelation of Na+ by diglyme for facilitated desolvation. More importantly, it promotes concentrated electron cloud distribution around PF6 - in the solvates and promotes their preferential decomposition. A desired inorganic-rich SEI is generated with compositional uniformity, high ionic conductivity, and high Young's modulus. Consequently, a record-high Coulombic efficiency over 99.9% is achieved at an ultralow temperature of -55 °C, and a 1 Ah capacity pouch cell of initial anode-free sodium metal battery retains 95% of the first discharge capacity over 100 cycles at -25 °C. This study thus provides new insights for formulating electrolytes toward increased Na reversibility at LT.