A structural study on a specific Li-ion ordered complex in dimethyl carbonate-based dual-cation electrolytes.

Dimethyl carbonate (DMC) is a linear carbonate solvent commonly used as an electrolyte for electric double-layer capacitors (EDLCs) and Li-ion batteries. However, there are serious problems with the use of DMC as an electrolyte solvent: (1) low ionic conductivity when using Li salts (e.g. LiBF4) and (2) liquid-liquid phase separation when using spiro-type quaternary ammonium salts (e.g. SBPBF4). Dual-cation electrolytes, i.e., bi-salt (SBPBF4 and LiBF4) in DMC, are promising candidates to avoid the phase separation issue and to enhance the total and Li+ conductivities. Herein, we reported a specific Li-ion structure in DMC-based dual-cation electrolytes by combining high-energy X-ray total scattering (HEXTS) and all-atom molecular dynamics (MD) simulations. Quantitative radial distribution function analysis based on experimental and simulation results revealed that the phase-separated SBPBF4/DMC (i.e., the bottom phase of 1 M SBPBF4/DMC) forms long-range ion ordering based on the structured SBP+-BF4- ion pairs. When adding LiBF4 salt into SBPBF4/DMC (i.e., dual-cation electrolyte), the ordered SBP+-BF4- structure disappeared owing to the formation of Li-ion solvation complexes. We found that in the dual-cation electrolyte Li ions form multiple Li+-Li+ ordered complexes in spite of relatively low Li-salt concentration (1 M), being a promising Li+-conducting medium with reduced Li salt usage and low viscosity.

A structural and electrochemical study of lithium-ion battery electrolytes using an ethylene sulfite solvent: from dilute to concentrated solutions.

We report the structural and electrochemical characteristics of lithium (Li)-ion battery (LIB) electrolyte solutions using an ethylene sulfite (ES) solvent that is used as an electrolyte additive for LIBs. From dilute to highly concentrated ES solutions with lithium bis(fluorosulfonyl)amide (LiFSA), the formation of Li-ion complexes was investigated using a combined Raman and infrared spectroscopy study with the aid of density functional theory (DFT) calculations to quantitatively determine their solvation and ion-pair structures depending on the Li salt concentration (cLi). The results reveal that, in the dilute solutions (<1.0 mol dm-3), Li-ions are fully solvated with ES molecules to form a tetrahedral-like [Li(ES)4]+ complex; however, with the increasing cLi (up to 2.5 mol dm-3), the Li-ion complex changes in structure to form contact ion-pairs coordinated with both ES and FSA anions. It also reveals that further increasing cLi to approximately 3.0 mol dm-3 leads to the ionic aggregate formation, i.e., multiple Li-ion complexes linked via several FSA anions. LiFSA/ES electrolyte solutions exhibited a reversible Li-ion insertion/deinsertion reaction into/from the graphite anode irrespective of cLi. This is due to the high-grade ES-derived passivation films on the electrode as a result of the preferential reductive decomposition of the ES molecules trapped within the Li-ion coordination sphere. According to the charge-discharge test, the concentrated LiFSA/ES solutions exhibited the high C-rate performance, which is superior to the concentrated electrolyte solutions using conventional organic solvents.

Efficacy of pazopanib in FGFR1-amplified uterine carcinosarcoma: A case report.

•We reported the use of pazopanib in the treatment of recurrent uterine carcinosarcoma with FGFR1 amplification.•The expert tumor board recommended pazopanib for off-label use based on genetic mutations found in cancer gene panels.•Pazopanib, a multi-tyrosine kinase inhibitor, was effective against recurrent uterine sarcoma with FGFR1 amplification.•Pazopanib maintained the patient's quality of life for a certain period.

Fluorophosphate-Based Nonflammable Concentrated Electrolytes with a Designed Lithium-Ion-Ordered Structure: Relationship between the Bulk Electrolyte and Electrode Interface Structures.

We propose a molecular design for lithium (Li)-ion-ordered complex structures in nonflammable concentrated electrolytes that facilitates the Li-ion battery (LIB) electrode reaction to produce safer LIBs. The concentrated electrolyte, composed of Li bis(fluorosulfonyl)amide (FSA) salt and a nonflammable tris(2,2,2-trifluoroethyl) phosphate (TFEP) solvent, showed no electrode reaction (i.e., no Li-ion intercalation into the negative graphite electrode); however, introducing a small molecular additive (acetonitrile [AN]) into concentrated TFEP-based electrolytes is shown to improve the battery electrode reaction, leading to reversible charge/discharge behavior. Combined high-energy X-ray total scattering experiments incorporating all-atom molecular dynamics simulations were used to visualize Li-ion complexes at the molecular level and revealed that (1) Li ions form mononuclear complexes in a concentrated LiFSA/TFEP (without additives) owing to solvation steric effects arising from the molecular size of TFEP and (2) adding a small-sized additive, AN, reduces the steric effect and triggers a change in Li-ion structures, i.e., the formation of a specific Li-ion-ordered structure linked via FSA anions. These Li-ion-ordered complexes stabilize the energy of the lowest unoccupied molecular orbital (LUMO) on FSA anions, which is key to producing an anion-derived solid electrolyte interphase (SEI) at the graphite electrode. We performed in situ surface-enhanced infrared absorption spectroscopy and discussed the electrode/electrolyte interface and SEI formation mechanisms in TFEP-based concentrated electrolyte systems.

Fluorinated alkyl-phosphate-based electrolytes with controlled lithium-ion coordination structure.

Herein, we propose Li-ion solvation-controlled electrolytes based on non-flammable organic solvent TFEP and an LiFSA salt [TFEP: tris(2,2,2-trifluoroethyl)phosphate, LiFSA: lithium bis(fluorosulfonyl)amide] to allow Li-ion insertion into a graphite electrode for Li-ion batteries. Comprehensive structural study based on (1) infrared (IR)/Raman spectroscopy, (2) high-energy X-ray total scattering (HEXTS), and (3) molecular dynamics (MD) simulation revealed the solvation (or coordination) structures of Li ions in TFEP-based electrolytes at the molecular level. In binary LiFSA/TFEP with a Li salt concentration (cLi) < 1.0 mol dm-3, Li ions are coordinated with both TFEP and FSA components; in detail, two TFEP molecules coordinate in an O-donating monodentate manner and one FSA in an O-donating bidentate manner to form [Li(TFEP)2(bi-FSA)] as the major species. We demonstrated that adding acetonitrile (AN) to the LiFSA/TFEP electrolytes caused structural changes in the Li-ion complexes. The bi-FSA bound to the Li ion changed its coordination mode to mono-FSA, which was induced by solvating AN molecules to Li ions. The redox reaction corresponding to insertion/deinsertion of Li ions into/from the graphite electrode successfully occurred in 1.0 mol dm-3 LiFSA/TFEP with an AN electrolyte system, while there was no or reduced Li-ion insertion in the electrolyte without AN. We discussed the relationship between the structure and electrode reaction of the Li-ion complexes based on the FSA-coordination characteristics; i.e., in LiFSA/TFEP with the AN system, the mono-FSA bound to the Li ion is easier to decoordinate due to weaker Li+mono-FSA- interactions rather than the Li+bi-FSA- interactions, which mainly contribute to charge-transfer at the electrode/electrolyte interface to allow Li-ion insertion/deinsertion in the graphite anode.

Two cases of recurrent uterine cervical cancer with arterio-enteric fistula treated by femoro-femoral artery bypass in hybrid operation room.

Little has been reported regarding aortic-enteric fistula (AEF) as a complication of gynecologic cancers because of its rarity. However, since it is lethal if left untreated, medical practitioners involved with gynecologic diseases should be aware of this deadly condition. In our hospital, we encountered two cases of cervical cancer complicated by AEF. In both cases, contrast computed tomography (CT) revealed leakage of the contrast material from an artery into the small intestine, indicating AEF. Endovascular procedures with complete embolization of the affected arteries and femoro-femoral artery bypass (f-f bypass) were performed in the hybrid operation room. The activities of daily living improved dramatically for both patients, and they survived for 3 months before dying from cervical cancer. While embolization by endovascular methods and f-f bypass performed in a hybrid operation room is, therefore, an available option for treating AEF, literature is lacking and more research is required to improve long-term outcomes for this disease.