Latest ArticlesSilicon is recognized as the most advantageous next-generation anode material for LIBs in terms of its extremely high theoretical capacity and appropriate operating voltage. However, the application of Si anode is limited by huge volume expansion emerging with cycling, which in turn induces the collapse of the electrode structure, resulting in rapid capacity decay. Here, we report a strategy using self-swelling artificial laponite to prepare a laponite/MXene/CNT composite framework with both rigidity and flexibility, which can excellently address these challenges of Si anode. The self-swelling artificial laponite participates in the construction of hierarchical and porous structures, providing sufficient buffer space to mitigate the volume expansion of the LixSi alloying reaction. Meanwhile, tough and tightly cross-linked silicate nanosheets can improve the mechanical strength of the framework for strong structural stability. More importantly, the negative charge between the layers of artificial laponite can effectively promote fast Li-ion transport in the electrode. This free-standing silicon anode enables the preparation of high areal capacity electrodes to further enhance the energy density of LIBs and a higher reversible capacity of 2381.8 mAh/g at 0.1 C after 50 cycles with an initial coulombic of 85.6%. This work provides a simple and practical fabrication strategy for developing high-performance Si-based batteries, which can speed up their commercialization.
For several decades, the promise of implementing of lithium (Li) metal anodes for Li batteries has been a "holy grail" for researchers. Herein, we have proposed a facile design of a MOF-derived Co3O4 nanoparticles modified nickel foam, i.e., Co3O4-NF, as a 3D host to achieve a uniform infusion of the molten Li. The molten Li was uniformly absorbed on the Co3O4-NF host only in 10 s due to its high Li lithiophilicity. The obtained Li-Co3O4-NF composite electrode shows high cycling stability in symmetric cells with low voltage hysteresis even at a high current density of 5 mA/cm2. The full cells of Li-Co3O4-NF/LiFePO4 can cycle for more than 500 cycles at 2C without obvious capacity decay. SEM after cycling and in situ optical microscope results suggest that the unique 3D host structure of the Li-Co3O4-NF anode plays key roles on suppressing the dendrite growth and decreasing the local current inhomogeneity. We believe this work might provide a new strategy for fabricating dendrite-free Li metal anodes and facilitate practical applications in Li batteries.
Co-crystal formation can improve the physicochemical properties of a compound, thus enhancing its druggability. Therefore, artificial intelligence-based co-crystal virtual screening in the early stage of drug development has attracted extensive attention from researchers. However, the complexity of developing and applying algorithms hinders it wide application. This study presents a data-driven co-crystal prediction method based on the XGBoost machine learning model of the scikit-learn package. The simplified molecular input line entry specification (SMILES) information of two compounds is simply inputted to determine whether a co-crystal can be formed. The data set includs the co-crystal records presented in the Cambridge Structural Database (CSD) and the records of no co-crystal formation from extant literature and experiments. RDKit molecular descriptors are adopted as the features of a compound in the data set. The developed model shows excellent performance in the proposed co-crystal training and validation sets with high accuracy, sensitivity, and F1 score. The prediction success rate of the model exceeds 90%. The model therefore provides a simple and feasible scheme for designing and screening co-crystal drugs efficiently and accurately.
Benefitting from the development of non-fullerene acceptors (NFAs), remarkable advances have been achieved with the power conversion efficiency (PCE) exceeding 19% over the last few years. However, the major achievement comes from fused ring electron acceptors (FREAs) with complex structures, leading to high cost. Hence, it is urgent to design new materials to resolve the cost issues concerning basic commercial requirements of organic solar cells. Recently, great progress has been made in fully non-fused ring electron acceptors (NFREAs) with only single-aromatic ring in the electron-donating core, which might achieve a fine balance between the efficiency and cost, thus accelerating the commercial application of organic solar cells. Therefore, this article summarizes the recent advances of fully NFREAs with efficiency over 10%, which may provide a guidance for developing the cost-effective solar cells.
Chiral organic-inorganic metal halide semiconductors (OIMHSs) have recently attracted numerous interests due to their unique chirality, structural tunability, and extensive physical properties. However, most reported chiral OIMHSs contain toxic lead, which will be a potential obstacle to their further applications. Herein, we successfully synthesized a novel chiral lead-free tin(Ⅳ)-based OIMHS [(R)-3-hydroxyquinuclidinium]2SnCl6 ([R-HQ]2SnCl6). It exhibits a wide band gap (Eg) of about 4.11 eV. Moreover, [R-HQ]2SnCl6 undergoes a phase transition around 330 K (Tc) and shows distinct dielectric switching characteristics with good repeatability. This work enriches the chiral lead-free OIMHS family and stimulates further exploration of chiral lead-free OIMHS switching materials
Recently, two-dimension (2D) materials have fueled considerable interest in the field of gas sensing to cope urgent demands at specific scenarios. Unfortunately, the susceptibility to ambient humidity, and/or fragile operation stability always frustrate their further practicability. To overcome these drawbacks, we proposed one novel flexible gas sensor based on bismuth selenide (Bi2Se3) nanoplates for sensitive NO2 detection at room temperature. The as-prepared Bi2Se3 sensor exhibited favorable sensing performance, including remarkable NO2 selectivity, high response of 120% and fast response time of 81 s toward 5 ppm NO2, an ultralow detection limit of 100 ppb, and nice stability. Besides, the excellent humidity tolerance and mechanical flexibility endowed Bi2Se3 sensors with admirable reliability under harsh working conditions. The first-principles calculation further revealed the insights of extraordinary NO2 selectivity and the underlying gas-sensing mechanism.
Materials with facilely tunable spin configurations based on metal-radical coordination systems have potential applications for electronics and spintronics. Here, we report the ground state conversion of copper corrole radicals from singlet to triplet via the extension of the π-conjugation system by benzo-fusion at the β-position of corrole ligand. NMR spectroscopy, SQUID measurements and computational studies all support the ferromagnetic coupling between the Cu(Ⅱ) center and corrole π-radical of benzo-fused copper corrole 2-Cu, which is in sharp contrast with the antiferromagnetic coupling in regular non-extended copper corroles. The triplet 2-Cu is highly stable in air, and X-ray diffraction analysis revealed its unique highly planar corrole macrocycle. This work offers a promising strategy for creating high-spin systems in non-innocent metallocorroles.
The rapid evolution of portable and wearable electronic devices has fueled the development of smart functional textiles that are able to conduct electricity, sense body movements, or store energy. One main challenge inhibiting the further development of functional textile-based electronics is the lack of robust functional fibers with suitable electrical, electrochemical and sensing functionalities. MXenes, an emerging family of two-dimensional (2D) materials, have shown to be promising candidates for producing functional fibers due to their exceptional electrical and electrochemical properties combined with solution processability. The unique ability of MXenes to readily form liquid crystal phases in various solvents has allowed them to generate additive-free fibers using a wet spinning process. In this work, we review the recent exciting developments in the fabrication of neat MXenes fibers and present a critical evaluation of practical challenges in MXenes processing that influence the macroscale material properties and the performance of the subsequent devices. We also provide our assessment for the future opportunities and challenges in producing MXene fibers to help pave the way for their widespread use in advanced wearable applications.
Molecular oxygen within Polyoxometalates (POMs) based compounds are ideal oxidants with high atom economy and its use results in the production of water as the only byproduct. Significant progress has been made in the development of catalytic methods for aerobic alcohol oxidation to have aldehydes and ketones with POMs based compounds. They are alternative to the use of traditional hypervalent iodine catalyst systems which are with molecular oxygen as a terminal oxidant. Further, POMs based catalysts can be applied to catalytic reactions with different modes of energization such as thermocatalysis, photocatalysis and electrocatalysis. This review summarizes the frontier advances in polyoxometalates for catalytic alcohol selective oxidation in thermocatalytic, electrocatalytic, and photocatalytic applications. The three advantages of POM catalysts in terms of performance, economy, and environmental protection are highlighted. These include the use of sol-gel and electrostatic assembly methods to increase the reaction surface area, reduce the use of precious metals, and improve the stability of POMs catalysts. The field of selective alcohol oxidation is advanced. Finally, the challenges of preparing more efficient and "green" catalysts are presented.
Phosphorus-doped mesoporous carbons (PMCs) were prepared using a self-doping and self-templating approach via direct pyrolysis of sodium phytate (C6H17NaO24P6). The one-pot method allows simultaneous carbonization and P doping, eliminating the need for pre-synthesis or post-activation treatment. The C6H17NaO24P6 is the source of both carbon and phosphorus, and the nano-Na4P2O7 particles produced during pyrolysis act as hard templates for the honeycomb mesoporous structure with high specific surface area (884–827 m2/g), large mesopore volume ratio (67%–75%) and rich phosphorus content (0.53–2.34 at%). As electrodes of supercapacitors in 6 mol/L KOH, the PMCs showed outstanding performance with a high capacitance of 202 F/g and excellent rate performance of 148 F/g at 30 A/g. In addition, the PMCs-based symmetrical supercapacitors can operate in an expanded working voltage of 0–1.6 V in 3 mol/L H2SO4 aqueous electrolytes with high-density energy of 11.8 Wh/kg.