High-voltage lithium-metal batteries enabled by ethylene glycol bis(propionitrile) ether-LiNO3 synergetic additives.

The employment of Li metal anodes is a key to realizing ultra-high energy batteries. However, the commercialization of lithium metal batteries (LMBs) remains challenging partially due to the thermodynamic instability and competitive oxidative decomposition of the solvent. Herein, a bi-functional electrolyte for stabilizing the interfaces of both the Li metal anode and LiCoO2 (LCO) cathode is designed by introducing lithium nitrate (LiNO3) through Ethylene Glycol Bis(Propionitrile) Ether (DENE). For the anode, the C8H12N2O2-LiNO3 coordination-solvation contributes to forming a stable Li3N-enhanced solid electrolyte interphase (SEI), which increases the average Li coulombic efficiency (CE) up to 98.5%. More importantly, in situ electrochemical dilatometry further reveals that the highly reversible behavior and a low volume expansion of lithium deposition are related to the stable Li3N-enhanced SEI. The designed electrolyte enables the Li‖LCO cell to achieve an average CE of 99.2% and a high capacity retention of 88.2% up to 4.6 V after 100 cycles. This work provides a strategic guidance in developing high-voltage Li‖LCO batteries with dual electrolyte additives.

The diversity and abundance of bacterial and fungal communities in the rhizosphere of Cathaya argyrophylla are affected by soil physicochemical properties.

Cathaya argyrophylla is an ancient Pinaceae species endemic to China that is listed on the IUCN Red List. Although C. argyrophylla is an ectomycorrhizal plant, the relationship between its rhizospheric soil microbial community and soil properties related to the natural habitat remains unknown. High-throughput sequencing of bacterial 16S rRNA genes and fungal ITS region sequences was used to survey the C. argyrophylla soil community at four natural spatially distributed points in Hunan Province, China, and functional profiles were predicted using PICRUSt2 and FUNGuild. The dominant bacterial phyla included Proteobacteria, Acidobacteria, Actinobacteria, and Chloroflexi, and the dominant genus was Acidothermus. The dominant fungal phyla were Basidiomycota and Ascomycota, while Russula was the dominant genus. Soil properties were the main factors leading to changes in rhizosphere soil bacterial and fungal communities, with nitrogen being the main driver of changes in soil microbial communities. The metabolic capacities of the microbial communities were predicted to identify differences in their functional profiles, including amino acid transport and metabolism, energy production and conversion, and the presence of fungi, including saprotrophs and symbiotrophs. These findings illuminate the soil microbial ecology of C. argyrophylla, and provide a scientific basis for screening rhizosphere microorganisms that are suitable for vegetation restoration and reconstruction for this important threatened species.

Elucidating the cation hydration ratio in water-in-salt electrolytes for carbon-based supercapacitors.

The solvation of cations is one of the important factors that determine the properties of electrolytes. Rational solvation structures can effectively improve the performance of various electrochemical energy storage devices. Water-in-Salt (WIS) electrolytes with a wide electrochemically stable potential window (ESW) have been proposed to realize high cell potential aqueous electrochemical energy storage devices relying on the special solvation structures of cations. The ratio of H2O molecules participating in the primary solvation structure of a cation (a cation hydration ratio) is the key factor for the kinetics and thermodynamics of the WIS electrolytes under an electric field. Here, acetates with different cations were used to prepare WIS electrolytes. And, the effect of different cation hydration ratios on the properties of WIS electrolytes was investigated. Various WIS electrolytes exhibited different physicochemical properties, including the saturated concentration, conductivity, viscosity, pH values and ESW. The WIS electrolytes with a low cation hydration ratio (<100%, an NH4-based WIS electrolyte) or a high cation hydration ratio (>100%, a K-based WIS electrolyte and a Cs-based WIS electrolyte) exhibit more outstanding conductivity or a wide ESW, respectively. SCs constructed from active carbon (AC) and these WIS electrolytes exhibited distinctive electrochemical properties. A SC with an NH4-based WIS electrolyte was characterized by higher capacity and better rate capability. SCs with a K-based WIS electrolyte and a Cs-based WIS electrolyte were characterized by a wider operating cell potential, higher energy density and better ability to suppress self-discharge and gas production. These results show that a WIS electrolyte with a low cation hydration ratio or a high cation hydration ratio is suitable for the construction of power-type or energy-type aqueous SCs, respectively. This understanding provides the foundation for the development of novel WIS electrolytes for the application of SCs.

EQCM Investigation of a Dual-Doped Polymer Electrode for Li-Ion Batteries with Improved Reversible Capacity.

Polymer-based materials with the incorporation of redox-active dopants serve as promising electrodes for Li-ion batteries but their use is restricted by the limited doping level and inevitable dissolution behavior of the dopants. Here, we proposed a conjugated polymer-based electrode with an assistant dopant to realize the reversible capacity contribution of a redox-active dopant. By employing phosphate anion (PO) as the assistant dopant to stable the polymer matrix, the reversible capacity was improved by introducing indigo carmine (IC) into the polymer electrode. Based on the real-time monitoring of the electrochemical quartz crystal microbalance toward the mass change, the charge storage behavior of the redox-active dopant IC was observed and the stabilizing effect of the assistant dopant PO was revealed. The modified electrode delivered an increased capacity of 191 mA h g-1, and the reversible capacity remained 56% higher than that of the PO-undoped electrode after 200 cycles. The dual-doping strategy with the assistant dopant and the redox-active dopant is used to develop advanced polymer-based electrodes for high-capacity and long-cycling batteries.

Insight into the reversible conversion-(de)incorporation of redox-active dopants within a polymer-based electrode.

We combined a microporous polymer backbone with an organic redox-active dopant to construct a reversible electrode system based on the conversion-(de)incorporation behaviour of the dopant. The correspondence between the reversible conversion-(de)incorporation mechanism of the dopant and the electrochemical performance of the designed electrode system was established by electrochemical quartz crystal microbalance and in situ Fourier transform infrared spectroscopy.

Hybrid Aqueous/Nonaqueous Water-in-Bisalt Electrolyte Enables Safe Dual Ion Batteries.

Dual ion batteries (DIBs) have recently attracted ever-increasing attention owing to the potential advantages of low material cost and good environmental friendliness. However, the potential safety hazards, cost, and environmental concerns mainly resulted from the commonly used nonaqueous organic solvents severely hinder the practical application of DIBs. Herein, a hybrid aqueous/nonaqueous water-in-bisalt electrolyte with both broad electrochemical stability window and excellent safety performance is developed. The lithium-based DIB assembled using KS6 graphite and niobium pentoxide as the active materials in the cathode and anode exhibits good comprehensive performance including capacity, cycling stability, rate performance, and medium discharge voltage. Initial capacities of ≈47.6 and 29.6 mAh g-1 retention after 300 cycles can be delivered with a medium discharge voltage of around 2.2 V in the voltage window of 0-3.2 V at the current density of 200 mA g-1 . Good rate performance for the battery can be indicated by 29.7 mAh g-1 discharge capacity retention at 400 mA g-1 . It is noteworthy that the coulombic efficiency of the battery can reach as high as 93.9%, which is comparable to that of the corresponding DIBs using nonaqueous organic electrolytes.

Quantitative assessment of the effect of pre-gestational diabetes and risk of adverse maternal, perinatal and neonatal outcomes.

Pregnancies complicated by pre-gestational diabetes (PGD) are associated with a higher rate of adverse outcomes, including an increased rage of preterm delivery, pregnancy-induced hypertension, pre-eclampsia, caesarean section, perinatal mortality, stillbirth, shoulder dystocia, macrosomia, small for gestational age, large for gestational age, low birth weight, neonatal hypoglycemia, neonatal death, low Apgar score, NICU admission, jaundice and respiratory distress. In the past two decades, numerous reports have been published regarding associations between PGD and risk of adverse outcomes. However, study results are inconsistent. To provide a synopsis of the current understanding of PGD for risk of adverse pregnancy outcomes, a random-effects meta-analysis over 40 million subjects from 100 studies was performed to calculate the pooled ORs. Potential sources of heterogeneity were systematically explored by multiple strata analyses and meta-regression. Overall, PGD were significantly associated with increased risk of preterm delivery (OR=3.48), LGA (OR=3.90), perinatal mortality (OR=3.39), stillbirth (OR=3.52), pre-eclampsia (OR=3.48), caesarean section (OR=3.52), NICU admission (OR=3.92), and neonatal hypoglycemia (OR=26.62). Significant results were also observed for 7 adverse outcomes with OR range from 1.54 to 2.82, while no association was found for SGA and respiratory distress after Bonferroni correction. We found that women with T1DM had higher risks for most of adverse pregnancy outcomes compared with women with T2DM. When stratified by study design, sample size, type of diabetes, geographic region, and study quality, significant associations remains. Our findings demonstrated that PGD is a strong risk-conferring factor for adverse maternal, perinatal and neonatal outcomes.