Scalable Synthesis of Si Nanosheets as Stable Anodes for Practical Lithium-Ion Batteries.

Silicon (Si) is regarded as a promising anode material because of its outstanding theoretical capacity, abundant existence, and mature infrastructure, but it suffers from an inherent volume expansion problem. Herein, a facile, scalable, and cost-effective route to produce Si nanosheets (Si NSs) using a low-cost silica fume as the start materials is proposed. After coated with carbon, the as-prepared Si-NSs@C material delivers ultrahigh capability (2770 mAh g-1 at 0.1 C), high initial Coulombic efficiency (87.9%), and long cycling lifespan (100 cycles at 0.5 C with a capacity decay rate of 0.3% per cycle). Beyond proof of concept, this work demonstrates a Si-NSs based pouch cell with an impressive capacity retention of 70.9% after 400 cycles, making it more promising for practical application. Revealed by the theoretical simulation, kinetics analysis, and in situ thickness/pressure detection, it is found that the superior performance of Si-NSs is attributed to the improved diffusivity and reversibility of Li+ ions and low expansion.

Agar-Derived Slope-Dominated Carbon Anode with Puparium Like Nano-Morphology for Cost-Effective SIBs.

The microstructure of hard carbons (HCs) including interlayer distance and lateral ab direction and pore size distribution plays a key role in regulating the sodium ions storage performance. Herein, by employing the gelatinous agar as a model precursor, series P-doping HCs (P-HC-x, x = 1, 2, 3, 4) are facilely prepared in batches via controllably regulating its crosslinking state by phytic acid (PA) at a low carbonization temperature of 750 °C, in which PA plays three roles (acid, flame retardant, and P-doping precursor) in promoting the final structure of P-HC-x. Among those, the puparium like P-HC-2 with expanded carbon interlayer distance of 3.91 Å and shortened lateral ab direction of 9.4 nm delivers a high reversible capacity of 394 mAh g-1 at 0.1 A g-1 with high increased slope capacity of 363 mAh g-1 as well as an ultrafast charge-discharge feature and a superlong cycle life. Pairing with the Na3 V2 (PO4 )3 cathode, the fabricated sodium-ion full cells exhibit the 132 mAh g-1 reversible capacity at 0.1 A g-1 , and 86% capacity retention after 100 cycles. This work successfully develops slope-dominated high-performance carbon anode, which will provide new insights for the microstructure regulation and design of other precursor-derivedHCs.

A specific and rapid method for detecting Bacillus and Acinetobacter species in Daqu.

Daqu is a spontaneous, solid-state cereal fermentation product used for saccharification and as a starter culture for Chinese Baijiu production. Bacillus and Acinetobacter, two dominant microbial genera in Daqu, produce enzymes and organic acids that influence the Daqu quality. However, there are no rapid analytical methods for detecting Bacillus and Acinetobacter. We designed primers specific to the genera Bacillus and Acinetobacter to perform genetic comparisons using the 16 S rRNA. After amplification of polymerase chain reaction using specific primers, high-throughput sequencing was performed to detect strains of Bacillus and Acinetobacter. The results showed that the effective amplification rates for Bacillus and Acinetobacter in Daqu were 86.92% and 79.75%, respectively. Thus, we have devised and assessed a method to accurately identify the species associated with Bacillus and Acinetobacter in Daqu, which can also hold significance for bacterial typing and identification.

Exploration of microbiome diversity of stacked fermented grains by flow cytometry and cell sorting.

Sauce-flavor baijiu is one of the twelve flavor types of Chinese distilled fermented product. Microbial composition plays a key role in the stacked fermentation of Baijiu, which uses grains as raw materials and produces flavor compounds, however, the active microbial community and its relationship remain unclear. Here, we investigated the total and active microbial communities of stacked fermented grains of sauce-flavored Baijiu using flow cytometry and high-throughput sequencing technology, respectively. By using traditional high-throughput sequencing technology, a total of 24 bacterial and 14 fungal genera were identified as the core microbiota, the core bacteria were Lactobacillus (0.08-39.05%), Acetobacter (0.25-81.92%), Weissella (0.03-29.61%), etc. The core fungi were Issatchenkia (23.11-98.21%), Monascus (0.02-26.36%), Pichia (0.33-37.56%), etc. In contrast, using flow cytometry combined with high-throughput sequencing, the active dominant bacterial genera after cell sorting were found to be Herbaspirillum, Chitinophaga, Ralstonia, Phenylobacterium, Mucilaginibacter, and Bradyrhizobium, etc., whereas the active dominant fungal genera detected were Aspergillus, Pichia, Exophiala, Candelabrochaete, Italiomyces, and Papiliotrema, etc. These results indicate that although the abundance of Acetobacter, Monascus, and Issatchenkia was high after stacked fermentation, they may have little biological activity. Flow cytometry and cell sorting techniques have been used in the study of beer and wine, but exploring the microbiome in such a complex environment as Chinese baijiu has not been reported. The results also reveal that flow cytometry and cell sorting are convenient methods for rapidly monitoring complex microbial flora and can assist in exploring complex environmental samples.

Gelation-Assisted Assembly of Large-Area, Highly Aligned, and Environmentally Stable MXene Films with an Excellent Trade-Off between Mechanical and Electrical Properties.

Layered MXene films have shown enormous potential for wide applications due to their high electrical conductivity and unique laminated microstructure. However, the intrinsic susceptibility to oxidation and the mechanical fragility of MXene films are the two major bottlenecks that prevent their widespread industrial applications. Here, a facile yet efficient assembly strategy is proposed to address these issues by increasing the alignment and compactness of MXene layers as well as strengthening the interlayer interactions. This method involves the gelation of MXene flakes with a multifunctional inorganic "mortar" polymer (ammonium polyphosphate, APP) followed by quasi-solid-state assembly enabled by a mechanical rolling process, by which the 3D gel network is transformed into 2D freestanding MXene films with unprecedented flake alignment and compactness. Besides, due to the multiple molecular-level interactions (hydrogen bonding, coordination bonding, and electrostatic force) between APP and MXene flakes, the resultant MXene-APP film (MAF) displays high mechanical strength (286.4 ± 20.3 MPa) and excellent electrical conductivity (8012.4 ± 325.6 S cm-1 ), along with remarkable environmental stability. As an application demonstration, MAF exhibits outstanding electromagnetic interference shielding effectiveness with long-term durability, highlighting the great potential of this gelation-assisted assembly strategy in fabricating large-area, high-performance MXene films for diverse real-world applications.