661,945 research outputs found
Li, C.P. -- 1976-82 -- Correspondence, Individual -- letter, 1976-09-07
No full textLetter from Li, C. P. to Sabin, Albert B. dated 1976-09-07.Sabin Collection Fair Use Policy</a
Mesoporous Si and multi-layered Si/C films by Pulsed Laser Deposition as Li-ion microbattery anodes
Full text linkSilicon is a very attractive Li-ion battery anode material due to its high theoretical capacity, but proper nanostructuring is needed to accommodate the large volume expansion/shrinkage upon reversible cycling. Hereby, novel mesoporous Si nanostructures are grown at room temperature by simple and rapid Pulsed Laser Deposition (PLD) directly on top of the Cu current collector surface. The samples are characterised from the structural/morphological viewpoint and their promising electrochemical behaviour demonstrated in lab-scale lithium cells. Depending on the porosity, easily tuneable by PLD, specific capacities approaching 250 μAh cm−2 are obtained. Successively, newly elaborated bicomponent silicon/carbon nanostructures are fabricated in one step by alternating PLD deposition of Si and C, thus resulting in novel multi-layered composite mesoporous films exhibiting profoundly improved performance. Alternated deposition of Si/C layers by PLD is proven to be a straightforward method to produce multi-layered anodes in one processing step. The addition of carbon and mild annealing at 400 °C stabilize the electrochemical performance of the Si based nanostructures in lab-scale lithium cells, allowing to reach very stable prolonged reversible cycling at improved specific capacity values. This opens the way to further reducing processing steps and processing time, which are key aspects when upscaling is sought
Wang Li (1900-1986)
No full textWang Li (Wang Liaoyi) was one of the three most prominent linguists in China in the 20th century. He was born August 10, 1900, in what is now Bobai County of the Guangxi Zhuang Autonomous Area
Li-iPSC differentiation into functional Li-HLCs.
No full text(A) Schematic illustration of the HLC differentiation procedure together with representative brightfield images taken at day 0, 5, 10 (scale bars = 250 μm) and 16 (scale bar 50 μm) during Li-HLC differentiation. (B) Li-HLCs at the end of differentiation protocol (day 16) co-stained positive for the hepatocyte specific markers HNF4A and Albumin, and for the pan epithelial marker E-Cadherin (C) by immunofluorescence analysis compared to isotype IgG control (scale bar 50 μm). (D) Fully differentiated Li-HLCs are functional with respect to the accumulation of lipids and glycogen as determined by Oil red O and Periodic Acid Schiff (PAS) staining (scale Bars 50 μm). Image quantification is described in S1 File.</p
Li3PO4-added garnet-type Li6.5La3Zr1.5Ta0.5O12 for Li-dendrite suppression
No full text
This paper proposes a strategy to stabilize the garnet/Li interface by introducing Li3PO4 as an additive in garnet-type Li6.5La3Zr1.5Ta0.5O12. The Li3PO4-added Li6.5La3Zr1.5Ta0.5O12 electrolyte exhibits a room temperature Li-ion conductivity of 1.4 x 10(-4) S cm(-1), which is less than that of the Li3PO4-free counterparts (4.6 x 10(-4) S cm(-1)). However, the presence of Li3PO4 improves the interfacial compatibility and suppresses Li-dendrite formation during Li-metal plating/stripping. The symmetric Li/garnet/Li cells with Li3PO4-added Li6.3La3Zr1.5Ta0.5O12 have been successfully cycled at a current density of 0.1 mA cm(-2) at 60 degrees C for 60 h; on contrast, the control cells with Li3PO4-free Li6.5La3Zr1.5Ta0.5O12 display noisy potential with large voltage polarization and get short-circuited completely after 33-h cycling under the same operating condition. The outstanding interface stability can be attributed to the in situ reaction of the Li flux with Li3PO4 to form a self-limiting and ion-conducting interphase, Li3P, which is confirmed experimentally. (C) 2017 Elsevier B.V. All rights reserved.</p
Regulating liquid and solid-state electrolytes for solid-phase conversion in Li–S batteries
No full textThe solid-phase conversion mechanism in lithium–sulfur (Li–S) batteries has emerged with many attractive advantages such as avoiding the parasitic “shuttle effect” of soluble polysulfides and allowing lean electrolyte operating conditions. Electrolyte regulation could be a vital strategy for taking full advantage of solid-phase conversion to realize high-energy Li–S batteries. This review aims to provide a comprehensive overview of the role of electrolyte regulation in promoting solid-phase conversion, thereby preparing high-energy Li–S batteries in liquid, quasi-solid-state, and solid-state media. The work introduces the significance and historical development roadmap of solid-phase conversion in Li–S batteries and explores a design strategy for functional electrolytes based on working mechanisms. Furthermore, it outlines the challenges and opportunities in developing modern Li–S batteries governed by solid-phase conversion. We aim to provide insights and design principles for regulating electrolytes to solve the challenges presented in Li–S batteries, and we hope to provide readers with guidelines for the development and utilization of high-energy Li–S batteries.No Full Tex
Class-C PA-VCO Cell for FSK and GFSK Transmitters
No full textIn this paper, a Class-C PA-VCO cell tailored to FSK/GFSK transmitters is presented. In the proposed solution, a Class-C VCO and a common-gate stage PA are stacked in a current-reuse architecture operating with 1.2 V power supply. The PA and the VCO efficiencies are maximized by adjusting their voltage headroom without the use of any DC-DC converters. The PA-VCO is inserted in a transmitter based on an open-loop architecture. The presented prototype, fabricated in 0.13 μm CMOS technology, occupies an active area of 0.2 mm2. A maximum TX efficiency of 17.5% is achieved while the TX is delivering an output power of -1 dBm at 2.45 GHz. A phase noise of -129 dBc/Hz at 2.5 MHz frequency offset results in a carrier-frequency drift below 7 Hz/s and an FSK error below 0.7%, which allows the transmitter to operate in open-loop while delivering long data-packets. The transmitter is also compliant to BLE specifications when FSK and GFSK modulations with index of 0.5 are applied
Interface-Engineered Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub>-Based Garnet Solid Electrolytes with Suppressed Li-Dendrite Formation and Enhanced Electrochemical Performance
No full textHigh grain-boundary resistance, Li-dendrite formation, and electrode/Li interfacial resistance are three major issues facing garnet-based solid electrolytes. Herein, interfacial architecture engineering by incorporating 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMP-TFSI) ionic liquid into a garnet oxide is proposed. The “soft” continuous BMP-TFSI coating with no added Li salt generates a conducting network facilitating Li+ transport and thus changes the ion conduction mode from point contacts to face contacts. The compacted microstructure suppresses Li-dendrite growth and shows good interfacial compatibility and interfacial wettability toward Li metal. Along with a broad electrochemical window larger than 5.5 V and an Li+ transference number that practically reaches unity, LiNi0.8Co0.1Mn0.1O2/Li and LiFePO4/Li solid-state batteries with the hybrid solid electrolyte exhibit superior cycling stability and low polarization, comparable to those with commercial liquid electrolytes, and excellent rate capability that is better than those of Li-salt-based ionic-liquid electrolytes.Accepted Author ManuscriptRST/Storage of Electrochemical Energ
Superatom Molecular Orbitals of Li@C-60 : Effects of the Li Position and the Substrate
Full text linkUnderstanding the character of superatom molecular orbitals (SAMOs) of fullerenes, especially those of the endohedral fullerenes, can potentially facilitate the utility of these molecules in organic electronics beyond conventional limits. However, the detailed nature of SAMOs in molecular films on substrates has yet to be unraveled. Using density functional theory, we investigate the wavefunction distributions and electronic structures of SAMO states of a Li@C-60 monolayer in dependence on the position of Li within the cage and the type of substrate species. We find that the characteristics of the SAMOs in terms of shape and energy are quite sensitive to the Li position due to different charge redistributions. The substrate affects the intermolecular distances in the Li@C-60 films and modifies the widths and dispersion of the SAMO bands while retaining energetics similar to that of the isolated Li@C-60 monolayer. The substrate also affects the SAMO effective masses, making it possible to tune them via substrate-induced interaction. A properly chosen substrate can so be beneficial for Li confinement and SAMO stability, reflecting the molecule-substrate interaction and the charge transfer at the interface. These findings provide insights into the design and engineering of SAMOs of molecular films
Tailoring Li6PS5BR ionic conductivity and understanding of its role in cathode mixtures for high performance all-solid-state Li-S batteries
No full textThe ultrafast ionic conductivity of Li 6 PS 5 Br, which is higher than 1 mS cm -1 at room temperature, makes it an attractive candidate electrolyte for the all-solid-state Li-S battery. A simple synthesis route with an easy scale up process is critical for practical applications. In this work, the highest room temperature ionic conductivity (2.58 × 10 -3 S cm -1 ) of Li 6 PS 5 Br is obtained by an optimal annealing temperature in a simple solid-state reaction method. Neutron diffraction and XRD show that the origin of the highest ionic conductivity is due to the higher purity, smaller mean lithium ion jumps and the optimal Br ordering over 4a and 4c sites. All-solid-state Li-S batteries using a S-C composite cathode in combination with the optimized Li 6 PS 5 Br electrolyte and Li-In anode show high (dis)charge capacities. Different cycling modes (charge-discharge and discharge-charge) reveal that the capacity of the S-C-Li 6 PS 5 Br/Li 6 PS 5 Br/Li-In battery arises from both the active S-C composite and the Li 6 PS 5 Br in the cathode mixture. The contribution of the latter is verified from all-solid-state batteries using Li 6 PS 5 Br and its analogues as active materials. Ex situ XRD and electrochemical performance results show that the contribution of capacity from Li 6 PS 5 Br in the cathode mixture may be associated with the decomposition product Li 2 S, while the Li 6 PS 5 Br in the bulk solid electrolyte layer is stable during cycling. Accepted Author ManuscriptRST/Storage of Electrochemical EnergyRST/Neutron and Positron Methods in Material
- …
