No abstract

Discovering new chemistry and materials to enable rechargeable batteries with higher capacity and energy density is of paramount importance. While Li metal is the ultimate choice of a battery anode, its low efficiency is still yet to be overcome. Many strategies have been developed to improve the reversibility and cycle life of Li metal electrodes. However, almost all of the results are limited to shallow cycling conditions (e.g., 1 mAh cm) and thus inefficient utilization (<1%). Here we achieve Li metal electrodes that can be deeply cycled at high capacities of 10 and 20 mAh cm with average Coulombic efficiency >98% in a commercial LiPF/carbonate electrolyte. The high performance is enabled by slow release of LiNO into the electrolyte and its subsequent decomposition to form a LiN and lithium oxynitrides (LiN O)-containing protective layer which renders reversible, dendrite-free, and highly dense Li metal deposition. Using the developed Li metal electrodes, we construct a Li-MoS full cell with the anode and cathode materials in a close-to-stoichiometric amount ratio. In terms of both capacity and energy, normalized to either the electrode area or the total mass of the electrode materials, our cell significantly outperforms other laboratory-scale battery cells as well as the state-of-the-art Li ion batteries on the market.

An organotrisulfide (RSSSR, R is an organic group) has three sulfur atoms which could be involved in multi-electron reduction reactions; therefore it is a promising electrode material for batteries. Herein, we use dimethyl trisulfide (DMTS) as a model compound to study its redox reactions in rechargeable lithium batteries. With the aid of XRD, XPS, and GC-MS analysis, we confirm DMTS could undergo almost a 4 e(-) reduction process in a complete discharge to 1.0 V. The discharge products are primarily LiSCH3 and Li2 S. The lithium cell with DMTS catholyte delivers an initial specific capacity of 720 mAh g(-1) DMTS and retains 82 % of the capacity over 50 cycles at C/10 rate. When the electrolyte/DMTS ratio is 3:1 mL g(-1) , the reversible specific energy for the cell including electrolyte can be 229 Wh kg(-1) . This study shows organotrisulfide is a promising high-capacity cathode material for high-energy rechargeable lithium batteries.

Background: The aim of the present study was to compare the effects of gliclazide, liraglutide, and metformin in type 2 diabetes mellitus (T2DM) patients with non-alcoholic fatty liver disease (NAFLD). Methods: Eighty-seven subjects were randomized to receive liraglutide, metformin, or gliclazide for 24 weeks. Primary outcomes included HbA1c levels, intrahepatic fat (IHF) content, and liver function. Results: Both HbA1c levels and IHF content were reduced after treatment in all three groups. However, HbA1c levels were lower in the liraglutide-and metformin-treated groups than in the gliclazide-treated group, and reductions in IHF content were greater with liraglutide than with gliclazide. Liraglutide and metformin treatments reduced weight and improved liver function. Changes in IHF content were positively correlated with reductions in serum alanine aminotransferase and triglyceride levels, as well as weight. At 24 weeks, reductions in IHF content were greater in subjects with weight loss ≥5%, changes in waistline ≤0 cm (including decreases in waistline), HbA1c reductions ≥2.5%, and HbA1c levels <6.5%. Conclusions: In T2DM patients with NAFLD, compared with liraglutide and metformin, gliclazide resulted in less improvement in liver function, reductions in IHF content and HbA1c levels, and less weight loss; in addition, slightly better improvements were achieved with liraglutide than with metformin.

Two extremely stable anthraquinone negolytes were synthesized from inexpensive precursors that potentially decrease the mass production cost. The carbon-linked anthraquinones eliminate S N 2 or S N Ar side reactions. Pairing with a Fe(CN) 6 3À/4À posolyte, they exhibited an open-circuit voltage of 1.0 V. By operating at pH 14, a record low capacity fade rate of <1% per year was demonstrated.

This study analyzes the energetic cost of CO2 separation using a pH swing created by electrochemical redox reactions of organic molecules involving PCET in aqueous electrolyte, and compares the experimental energetic cost to other methods.

Developing Na metal anodes that can be deeply cycled with high efficiency for a long time is a prerequisite for rechargeable Na metal batteries to be practically useful despite their notable advantages in theoretical energy density and potential low cost. Their high chemical reactivity with the electrolyte and tendency for dendrite formation are two major issues limiting the reversibility of Na metal electrodes. In this work, we introduce for the first time potassium bis(trifluoromethylsulfonyl)imide (KTFSI) as a bifunctional electrolyte additive to stabilize Na metal electrodes, in which the TFSI anions decompose into lithium nitride and oxynitrides to render a desirable solid electrolyte interphase layer while the K cations preferentially adsorb onto Na protrusions and provide electrostatic shielding to suppress dendritic deposition. Through the cooperation of the cations and anions, we have realized Na metal electrodes that can be deeply cycled at a capacity of 10 mAh cm for hundreds of hours.

Organotrisulfide (RSSSR) is a new class of high-capacity cathode materials for rechargeable lithium batteries. The organic R group can tune the structure and property of organotrisulfide as well as electrochemical performance in batteries. Herein, a nominal diphenyl trisulfide (DPTS, C6H5SSSC6H5) catholyte is reported for rechargeable lithium batteries. Three sulfur atoms allow 4e– storage per molecule, affording DPTS with a theoretical capacity of 428 mAh g–1. The DPTS catholyte is synthesized from a coupling reaction of diphenyl disulfide (DPDS) and elemental sulfur in liquid electrolyte at 70 °C. It is found that the DPTS catholyte is a mixture of DPTS, DPDS, and elemental sulfur in the electrolyte. The lithium cell with the DPTS catholyte delivers an initial specific capacity of 330 mAh g–1 DPTS and retains 79% of the initial capacity over 100 cycles at the C/2 rate. The cell delivers an initial discharge specific energy of 751 Wh kg–1 DPTS with a high energy efficiency of over 95% at the C/5 rate. The achievable energy density of the DPTS catholyte (1.0 M) is 158 Wh L–1. This study shows that DPTS is a promising high-capacity cathode material for highly reversible lithium batteries.