41 research outputs found

    Ternary polymer electrolytes incorporating pyrrolidinium-imide ionic liquids

    Get PDF
    Herein is reported the performance of ternary polymer electrolytes incorporating ionic liquids, showing higher ionic conductivity over a wide temperature range than binary polymer-salt systems, while guaranteeing higher safety compared to liquid, organic electrolytes or gel electrolytes. In particular, the electrochemical performance and the interactions between poly(ethylene oxide) (PEO), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and several pyrrolidinium-based ionic liquids is comparatively investigated. Eight different polymer electrolytes were produced to test the ionic conductivity and long-time (more than 1400 hours) cycling stability in symmetrical lithium cells. Thermal analysis was used to investigate the thermal stability and degree of crystallinity. Six of the eight investigated samples are found fully amorphous at room temperature. In general, the properties of the polymer electrolytes are influenced by both Ionic liquid ions. The ether function in the side chain of the pyrrolidinium increases the ionic conductivity but, in some cases, lowers the thermal and electrochemical stability

    Ionic liquid-based electrolytes for sodium-ion batteries : tuning properties to enhance the electrochemical performance of manganese-based layered oxide cathode

    Get PDF
    Ionic liquids (ILs) are considered as appealing alternative electrolytes for application in rechargeable batteries, including the next-generation sodium-ion batteries, because of their safe and eco-friendly nature, resulting from their extremely low volatility. In this work, two groups of advanced pyrrolidinium based ILs electrolytes are concerned, made by mixing sodium bis(fluorosulfonyl)imide (NaFSI) or sodium tri(fluoromethanesulfonyl)imide (NaTFSI) salts with N-Methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide (Pyr13FSI), N-Butyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (Pyr14FSI) and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI). The characterization of eight different electrolytes, including single anion electrolytes and binary anions mixtures, in terms of thermal properties, density, viscosity and conductivity as well as electrochemical stability window and cycling performance in room temperature sodium cells is reported here. Among all the blends, those containing Pyr14FSI outperform the others in terms of cell performance enabling the layered P2-Na0.6Ni0.22Al0.11Mn0.66O2 cathode to deliver about 140 mAh g-1 for more than 200 cycles

    Exceptional long-life performance of lithium-ion batteries using ionic liquid-based electrolytes

    Get PDF
    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Advanced ionic liquid-based electrolytes are herein characterized for application in high performance lithium-ion batteries. The electrolytes based on either N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr(14)TFSI), N-butyl-N-methylpyrrolidinium bis(fluoro-sulfonyl) imide (Pyr(14)FSI), N-methoxy-ethyl-N-methylpyrrolidinium bis(trifluoromethane-sulfonyl) imide (Pyr(12O1)TFSI) or N-N-diethyl-N-methyl-N-(2methoxyethyl) ammonium bis(trifluoromethanesulfonyl) imide (DEMETFSI) ionic liquids and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt are fully characterized in terms of ionic conductivity, viscosity, electrochemical properties and lithium-interphase stability. All IL-based electrolytes reveal suitable characteristics for application in batteries. Lithium half-cells, employing a LiFePO4 polyanionic cathode, show remarkable performance. In particular, relevant efficiency and rate-capability are observed for the Py14FSI-LiTFSI electrolyte, which is further characterized for application in a lithium-ion battery composed of the alloying Sn-C nanocomposite anode and LiFePO4 cathode. The IL-based full-cell delivers a maximum reversible capacity of about 160 mA h g(-1) (versus cathode weight) at a working voltage of about 3 V, corresponding to an estimated practical energy of about 160 W h kg(-1). The cell evidences outstanding electrochemical cycle life, i.e., extended over 2000 cycles without signs of decay, and satisfactory rate capability. This performance together with the high safety provided by the IL-electrolyte, olivine-structure cathode and Li-alloying anode, makes this cell chemistry well suited for application in new-generation electric and electronic devices

    Prognostic significance of sealed-off perforation in colon cancer: a prospective cohort study

    Get PDF
    Background Perforated colon cancer is a rare complication, but has a high risk of recurrence. However, most studies have not distinguished sealed-off perforation from free perforation, and the prognosis is unclear. The aim of this study was to evaluate the oncologic outcome of colon cancer with sealed-off perforation. Methods Eighty-six consecutive patients who underwent resection for colon cancer with sealed-off or free perforation were included. We defined sealed-off perforation as a colon perforation with localized abscess identified on operative, computed tomography, or pathologic findings, with no evidence of free perforation, including fecal contamination and dirty fluid collection in the peritoneal cavity. Oncologic outcomes were compared between patients with colon cancer with sealed-off perforation and free perforation using a log-rank test and Cox regression analysis. Results The sealed-off perforation group included 62 patients, and 24 patients were in the free perforation group. TNM stage and lymphatic, venous, and perineural invasion were similar between the groups. The median follow-up period was 28.9 months (range 0–159). The sealed-off perforation group had better prognosis compared with the free perforation group in terms of progression-free survival (PFS) and overall survival (OS), although there were no statistically significant differences in PFS (5-year PFS 53.7% vs. 40.5%, p = 0.148; 5-year OS 53.6% vs. 22.9%, p = 0.001). However, in multivariable analysis using the Cox progression test, sealed-off perforation did not show a significant effect on cancer progression (p = 0.138) and OS (p = 0.727). Conclusions Colon cancer with sealed-off perforation showed no difference in prognosis compared with free perforation.Not applicable

    The acidic tumor microenvironment enhances PD-L1 expression via activation of STAT3 in MDA-MB-231 breast cancer cells

    Get PDF
    Abstract Tumor acidosis, a common phenomenon in solid cancers such as breast cancer, is caused by the abnormal metabolism of cancer cells. The low pH affects cells surrounding the cancer, and tumor acidosis has been shown to inhibit the activity of immune cells. Despite many previous studies, the immune surveillance mechanisms are not fully understood. We found that the expression of PD-L1 was significantly increased under conditions of extracellular acidosis in MDA-MB-231 cells. We also confirmed that the increased expression of PD-L1 mediated by extracellular acidosis was decreased when the pH was raised to the normal range. Gene set enrichment analysis (GSEA) of public breast cancer patient databases showed that PD-L1 expression was also highly correlated with IL-6/JAK/STAT3 signaling. Surprisingly, the expression of both phospho-tyrosine STAT3 and PD-L1 was significantly increased under conditions of extracellular acidosis, and inhibition of STAT3 did not increase the expression of PD-L1 even under acidic conditions in MDA-MB-231 cells. Based on these results, we suggest that the expression of PD-L1 is increased by tumor acidosis via activation of STAT3 in MDA-MB-231 cells.This work was supported by grants from the National Research Foundation of Korea (NRF) funded by the Korean government (NRF-2018R1A5A2025964) and the Seoul National University Hospital (SNUH) Research Fund (04–20200230). This study was also carried out with support from the R&D Program for Forest Science Technology (Project No. 2020195A00–2122-BA01) of the Korea Forest Service (Korea Forestry Promotion Institute) and Cooperative Research Program for the Agriculture Science and Technology Development (Project No. PJ01589402 and No. PJ016202022) Rural Development Administration, Republic of Korea

    COVID-19 variants’ cross-reactivity on the paper microfluidic particle counting immunoassay

    No full text
    SARS-CoV-2 has mutated many times since the onset of the COVID-19 pandemic, and the omicron is currently the most dominant variant. Determining the specific strain of the virus is beneficial in providing proper care and containment of the disease. We have previously reported a novel method of counting the number of particle immunoagglutination on a paper microfluidic chip using a smartphone-based fluorescence microscope. A single-copy-level detection was demonstrated from clinical saline gargle samples. In this work, we further evaluated two different SARS-CoV-2 monoclonal antibodies to spike vs. nucleocapsid antigens for detecting omicron vs. delta and spike vs. nucleocapsid proteins. The SARS-CoV-2 monoclonal antibody to nucleocapsid proteins could distinguish omicron from delta variants and nucleocapsid from spike proteins. However, such distinction could not be found with the monoclonal antibody to spike proteins, despite the numerous mutations found in spike proteins among variants. This result may suggest a clue to the role of nucleocapsid proteins in recognizing different variants.Technology and Research Initiative Fund (TRIF) of the Arizona Board of RegentsNo embargo COVID-19This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    A Total Crop-Diagnosis Platform Based on Deep Learning Models in a Natural Nutrient Environment

    No full text
    This paper proposes a total crop-diagnosis platform (TCP) based on deep learning models in a natural nutrient environment, which collects the weather information based on a farm’s location information, diagnoses the collected weather information and the crop soil sensor data with a deep learning technique, and notifies a farm manager of the diagnosed result. The proposed TCP is composed of 1 gateway and 2 modules as follows. First, the optimized farm sensor gateway (OFSG) collects data by internetworking sensor nodes which use Zigbee, Wi-Fi and Bluetooth protocol and reduces the number of sensor data fragmentation times through the compression of a fragment header. Second, the data storage module (DSM) stores the collected farm data and weather data in a farm central server. Third, the crop self-diagnosis module (CSM) works in the cloud server and diagnoses by deep learning whether or not the status of a farm is in good condition for growing crops according to current weather and soil information. The TCP performance shows that the data processing rate of the OFSG is increased by about 7% compared with existing sensor gateways. The learning time of the CSM is shorter than that of the long short-term memory models (LSTM) by 0.43 s, and the success rate of the CSM is higher than that of the LSTM by about 7%. Therefore, the TCP based on deep learning interconnects the communication protocols of various sensors, solves the maximum data size that sensor can transfer, predicts in advance crop disease occurrence in an external environment, and helps to make an optimized environment in which to grow crops

    A multiple electrolyte concept for lithium-metal batteries

    No full text
    A cross-linked polymer membrane formed by poly(ethylene oxide) (PEO), N-methoxyethyl-N-methylpyrrolidium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (Pyr12O1FTFSI) ionic liquid and LiFTFSI salt is proposed as the electrolyte for lithium-metal batteries. The ternary membrane has a PEO:Pyr12O1FTFSI:LiFTFSI composition of 20:6:4 by mole, which ensures thermal stability up to 220 °C, overall ionic conductivity of 10â\u88\u92 3S cmâ\u88\u92 1at 40 °C and suitable Li+transport properties. Combined with the LiFePO4composite electrode, whose pores are filled with the Pyr12O1FTFSI:LiFTFSI electrolyte, and Li-metal anode, it yields Li/LiFePO4cells delivering at 40 °C stable capacity (150 mAh gâ\u88\u92 1or 0.7 mAh cmâ\u88\u92 2) with coulombic efficiency higher than 99.5%. Impedance spectroscopy measurements reveal low resistance of the electrode/electrolyte interface at both the anode and the cathode. Preliminary results at 20 °C indicates a capacity of 130 mAh gâ\u88\u92 1at C/10 rate (17 mA gâ\u88\u92 1) with coulombic efficiency higher than 99.5%, thereby suggesting PEO:Pyr12O1FTFSI:LiFTFSI as suitable electrolyte for lithium-metal polymer batteries for stationary storage applications, coupled for example with PV and wind generation
    corecore