Alkali metal-oxygen batteries promise high gravimetric energy densities but suffer from low rate capability, poor cycle life and safety hazards associated with metal anodes. Here we describe a safe, ...high-rate and long-life oxygen battery that exploits a potassium biphenyl complex anode and a dimethylsulfoxide-mediated potassium superoxide cathode. The proposed potassium biphenyl complex-oxygen battery exhibits an unprecedented cycle life (3,000 cycles) with a superior average coulombic efficiency of more than 99.84% at a high current density of 4.0 mA cm
. We further reduce the redox potential of biphenyl by adding the electron-donating methyl group to the benzene ring, which successfully achieved a redox potential of 0.14 V versus K/K
. This demonstrates the direction and opportunities to further improve the cell voltage and energy density of the alkali-metal organic-oxygen batteries.
Li-ion batteries are essential technologies for electronic products in the daily life. However, serious fire safety concerns that are closely associated with the flammable liquid electrolyte remains ...a key challenge. Tremendous effort has been devoted to designing nonflammable liquid electrolytes. It is critical to gain comprehensive insights into nonflammability design and inspire more efficient approaches for building safer Li-ion batteries. This review presents current mechanistic understanding of safety issues and discusses state-of-the-art nonflammable liquid electrolytes design for Li-ion batteries based on molecule, solvation, and battery compatibility level. Various safety test methods are discussed for reliable safety risk evaluation. Finally, the challenges and perspectives of the nonflammability design for Li-ion electrolytes are summarized.
TAZ promotes growth, development and tumorigenesis by regulating the expression of target genes. However, the manner in which TAZ orchestrates the transcriptional responses is poorly defined. Here we ...demonstrate that TAZ forms nuclear condensates through liquid-liquid phase separation to compartmentalize its DNA-binding cofactor TEAD4, coactivators BRD4 and MED1, and the transcription elongation factor CDK9 for transcription. TAZ forms phase-separated droplets in vitro and liquid-like nuclear condensates in vivo, and this ability is negatively regulated by Hippo signalling through LATS-mediated phosphorylation and is mediated by the coiled-coil (CC) domain. Deletion of the TAZ CC domain or substitution with the YAP CC domain prevents the phase separation of TAZ and its ability to induce the expression of TAZ-specific target genes. Thus, we identify a mechanism of transcriptional activation by TAZ and demonstrate that pathway-specific transcription factors also engage the phase-separation mechanism for efficient and specific transcriptional activation.
Redox flow batteries are promising technologies for large-scale electricity storage, but have been suffering from low energy density and low volumetric capacity. Here we report a flow cathode that ...exploits highly concentrated sulphur-impregnated carbon composite, to achieve a catholyte volumetric capacity 294 Ah l(-1) with long cycle life (>100 cycles), high columbic efficiency (>90%, 100 cycles) and high energy efficiency (>80%, 100 cycles). The demonstrated catholyte volumetric capacity is five times higher than the all-vanadium flow batteries (60 Ah l(-1)) and 3-6 times higher than the demonstrated lithium-polysulphide approaches (50-117 Ah l(-1)). Pseudo-in situ impedance and microscopy characterizations reveal superior electrochemical and morphological reversibility of the sulphur redox reactions. Our approach of exploiting sulphur-impregnated carbon composite in the flow cathode creates effective interfaces between the insulating sulphur and conductive carbon-percolating network and offers a promising direction to develop high-energy-density flow batteries.
A series of solid supramolecules based on acrylamide–phenylpyridium copolymers with various substituent groups (P−R: R=−CN, −CO2Et, −Me, −CF3) and cucurbit7uril (CB7) are constructed to exhibit ...tunable second‐level (from 0.9 s to 2.2 s) room‐temperature phosphorescence (RTP) in the amorphous state. Compared with other solid supramolecules P−R/CB7 (R=−CN, −CO2Et, −Me), P−CF3/CB7 displays the longest lifetime (2.2 s), which is probably attributed to the fluorophilic interaction of cucurbiturils leading to a uncommon host–guest interaction between 4‐phenylpyridium with −CF3 and CB7. Furthermore, the RTP solid supramolecular assembly (donors) can further react with organic dyes Eosin Y or SR101 (acceptors) to form ternary supramolecular systems featuring ultralong phosphorescence energy transfer (PpET) and visible delayed fluorescence (yellow for EY at 568 nm and red for SR101 at 620 nm). Significantly, the ultralong multicolor PpET supramolecular assembly can be further applied in fields of anti‐counterfeiting and information encryption and painting.
Solid supramolecules based on acrylamide–phenylpyridium copolymers with various substituent groups and cucurbit7uril not only exhibit tunable ultralong phosphorescence with lifetimes varying from 0.9 s to 2.2 s, but also co‐assemble with organic dyes Eosin Y or SR101 to display high‐performance phosphorescence energy transfer with multicolor delayed fluorescence properties.
We report the intrinsic oxygen reduction reaction (ORR) activity of polycrystalline palladium, platinum, ruthenium, gold, and glassy carbon surfaces in 0.1 M LiClO4 1,2-dimethoxyethane via rotating ...disk electrode measurements. The nonaqueous Li+-ORR activity of these surfaces primarily correlates to oxygen adsorption energy, forming a “volcano-type” trend. The activity trend found on the polycrystalline surfaces was in good agreement with the trend in the discharge voltage of Li-O2 cells catalyzed by nanoparticle catalysts. Our findings provide insights into Li+-ORR mechanisms in nonaqueous media and design of efficient air electrodes for Li-air battery applications.
Realizing a reversible and long-life nonaqueous lithium–oxygen (Li–O 2 ) battery has been proven extremely challenging due to reactive reaction products/intermediates that rapidly corrode and ...passivate the cathode. In this work, we effectively protect the cathode from oxygenated side reactions by manipulating the fluxes of reduced discharge mediator (rDM) and O 2 , thereby creating a steady-state rDM-rich region which completely covers the cathode. This rDM-rich region acts as a dynamic O 2 shield and isolates the cathode from oxygen reactions. We demonstrate that this strategy eliminates 98% of the by-products on the cathode, achieving a more than 10-fold increase in cycle life compared to conventional dual-mediator cells. A diffusion-reaction model is developed to assist understanding of the system and to guide future design. This work demonstrates an effective approach to achieve degradation-free cathodes for efficient and long-life Li–O 2 batteries.
Highly soluble iodide/triiodide (I-/I3-) couples are one of the most promising redox-active species for high-energy-density electrochemical energy storage applications. However, to ensure high ...reversibility, only two-thirds of the iodide capacity is accessed and one-third of the iodide ions act as a complexing agent to stabilize the iodine (I2), forming I3- (I2I-). Here, we exploit bromide ions (Br-) as a complexing agent to stabilize the iodine, forming iodine-bromide ions (I2Br-), which frees up iodide ions and increases the capacity. Applying this strategy, we demonstrate a novel zinc/iodine-bromide battery to achieve an energy density of 101 W h Lposolyte+negolyte-1 (or 202 W h Lposolyte-1), which is the highest energy density achieved for aqueous flow batteries to date. This strategy can be further generalized to nonaqueous iodide-based batteries (i.e. lithium/polyiodide battery), offering new opportunities to improve high-energy iodide-based energy storage technologies.
Measuring multiple omics profiles from the same single cell opens up the opportunity to decode molecular regulation that underlies intercellular heterogeneity in development and disease. Here, we ...present co-sequencing of microRNAs and mRNAs in the same single cell using a half-cell genomics approach. This method demonstrates good robustness (~95% success rate) and reproducibility (R
= 0.93 for both microRNAs and mRNAs), yielding paired half-cell microRNA and mRNA profiles, which we can independently validate. By linking the level of microRNAs to the expression of predicted target mRNAs across 19 single cells that are phenotypically identical, we observe that the predicted targets are significantly anti-correlated with the variation of abundantly expressed microRNAs. This suggests that microRNA expression variability alone may lead to non-genetic cell-to-cell heterogeneity. Genome-scale analysis of paired microRNA-mRNA co-profiles further allows us to derive and validate regulatory relationships of cellular pathways controlling microRNA expression and intercellular variability.
Cholesterol is dynamically transported among membrane-bound organelles primarily by nonvesicular mechanisms. Sterol transfer proteins (STPs) bind cholesterol in their hydrophobic pockets and ...facilitate its transfer across the aqueous cytosol. However, STPs alone may not account for the specific and efficient movement of cholesterol between intracellular membranes. Accumulating evidence has shown that membrane contact sites (MCSs), regions where two distinct organelles are in close apposition to one another, can facilitate STP-mediated cholesterol trafficking in a cell. At some MCSs, cholesterol can move against its concentration by using phosphatidylinositol 4-phosphate (PI4P) metabolism as the driving force. Finally, the emergence of more MCSs and the discovery of a new STP family further highlight the crucial roles of MCSs and STPs in intracellular cholesterol transport.
The close apposition between two cellular organelles allows efficient cholesterol transfer from one organelle to another.
Many STPs shuttle cholesterol between two adjacent organelles.
For some STPs, the metabolism of phosphoinositides drives cholesterol transport against its concentration gradient.
The list of membrane contacts is continuously expanding and a new STP family was recently identified.
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