Exciton Localization Modulated by Ultradeep Moiré Potential in Twisted Bilayer γ-Graphdiyne.

Twisted moiré superlattice is featured with its moiré potential energy, the depth of which renders an effective approach to strengthening the exciton-exciton interaction and exciton localization toward high-performance quantum photonic devices. However, it remains as a long-standing challenge to further push the limit of moiré potential depth. Herein, owing to the p orbital induced band edge states enabled by the unique sp-C in bilayer γ-graphdiyne (GDY), an ultradeep moiré potential of ∼289 meV is yielded.

[Prenatal diagnosis and genetic analysis of a fetus with partial deletion of Yq and mosaicism of 45,X].

Objective: To carry out prenatal diagnosis and genetic analysis for a fetus with disorders of sex development (DSDs).

Methods: A fetus with DSDs who was identified at the Shenzhen People's Hospital in September 2021 was selected as the study subject. Combined molecular genetic techniques including quantitative fluorescence PCR (QF-PCR), multiplex ligation-dependent probe amplification (MLPA), chromosomal microarray analysis (CMA), quantitative real-time PCR (qPCR), as well as cytogenetic techniques such as karyotyping analysis and fluorescence in situ hybridization (FISH) were applied.

[Analysis for 6-methyladenine modification of DNA in chorionic tissue from aborted fetuses with monosomy 21].

Objective: To study the correlation of genome-wide distribution of 6-methyladenine (6mA) of DNA in chorionic tissues from abortuses with monosomy 21.

Methods: Genomic DNA was extracted from chorionic samples from four abortuses with monosomy 21 and four without. After quality and purity test, partial DNA was subjected to chromatin immunoprecipitation with anti-6mA antibody, and then identified by sequencing.

Molecular crowding electrolytes for high-voltage aqueous batteries.

Developing low-cost and eco-friendly aqueous electrolytes with a wide voltage window is critical to achieve safe, high-energy and sustainable Li-ion batteries. Emerging approaches using highly concentrated salts (21-55 m (mol kg)) create artificial solid-electrode interfaces and improve water stability; however, these approaches raise concerns about cost and toxicity. Molecular crowding is a common phenomenon in living cells where water activity is substantially suppressed by molecular crowding agents through altering the hydrogen-bonding structure.

Critical Role of Anion Donicity in LiS Deposition and Sulfur Utilization in Li-S Batteries.

Lithium-sulfur batteries offer a high theoretical gravimetric energy density and low cost, but the full utilization of the sulfur electrode has been limited by the premature passivation of insulating lithium sulfide (LiS). Anion has been one of the major parameters to improve Li-S batteries in addition to solvent, additives, and electrode structures. Here, we reveal the role of anion donicity on the passivation of Li-S battery and its underlying working mechanism.

A high-rate and long-life organic-oxygen battery.

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.

Cation-Directed Selective Polysulfide Stabilization in Alkali Metal-Sulfur Batteries.

Alkali metal sulfur redox chemistry offers promising potential for high-energy-density energy storage. Fundamental understanding of alkali metal sulfur redox reactions is the prerequisite for rational designs of electrode and electrolyte. Here, we revealed a strong impact of alkali metal cation (Li, Na, K, and Rb) on polysulfide (PS) stability, redox reversibility, and solid product passivation.

Superoxide Stabilization and a Universal KO Growth Mechanism in Potassium-Oxygen Batteries.

Rechargeable potassium-oxygen (K-O ) batteries promise to provide higher round-trip efficiency and cycle life than other alkali-oxygen batteries with satisfactory gravimetric energy density (935 Wh kg ). Exploiting a strong electron-donating solvent, for example, dimethyl sulfoxide (DMSO) strongly stabilizes the discharge product (KO ), resulting in significant improvement in electrode kinetics and chemical/electrochemical reversibility. The first DMSO-based K-O battery demonstrates a much higher energy efficiency and stability than the glyme-based electrolyte.

Critical Role of Redox Mediator in Suppressing Charging Instabilities of Lithium-Oxygen Batteries.

Redox mediators have been widely applied to reduce the charge overpotentials of lithium-oxygen (Li-O2) batteries. Here, we reveal the critical role of redox mediator in suppressing the charging instability of Li-O2 batteries. Using high temporal resolution online electrochemical mass spectrometry, we show that charging with redox mediators (using lithium bromide as a model system) significantly reduces parasitic gas evolution and improves oxygen recovery efficiency.

Sulphur-impregnated flow cathode to enable high-energy-density lithium flow batteries.

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)).