Lithium-ion batteries (LIBs) have profoundly affected most aspects of human's society in recent years. [1] With wide applications of smarter electronics and electric vehicles, the fast charging/discharging capability and safety issues became the key challenges for further commercialization of LIBs. [2] However, this requirement might be hardly satisfied if the anode were still graphite-based materials, because of the safety issues of short circuits caused by lithium dendrite formation at high charge rates when near the working potential of graphite (only 0.2 V higher than Li + /Li). [3] Although insertion-type Li 4 Ti 5 O 12 (LTO) anode has an outstanding high-rate performance and a safety working potential at about 1.55 V (vs Li + /Li), it exhibits a rather low theoretical specific capacity of 175 mAh g −1 , which would severely limit the energy density of batteries. [4] Recently, the conversion and alloying anode materials with high specific capacities have been reported to promote their rate performance via introducing nano or porous structures to shorten diffusion distances. However, they still face many problems such as huge volume changes, electrolyte decomposition, low initial Coulombic efficiency and limited cycling life. [5] Notably, nano or porous materials usually exhibit enhanced rate performance but are not preferred by industry for the intrinsic shortage of volumetric energy density. [6] Thus, it is essential to explore anode materials combined with high rate performance, satisfying capacity and safety.Recently, niobium pentoxide (Nb 2 O 5 ) has drawn wide attentions and is expected as a suitable alternative anode material for its ultrafast Li storage kinetics, promising capacity and safe operating potential. [7] The Nb 2 O 5 owns various configurations under different preparation conditions, which are denoted by letters TT, T, B, M, and H. [8] Among these crystals, the T-type Nb 2 O 5 (T-Nb 2 O 5 ) has received the highest attention because it shows little structural change on intercalation (no phase transition) and high-rate behavior so called as an "intercalation pseudocapacitance" material. [9] However, its specific capacity is still below 200 mAh g −1 (1.0-3.0 V vs Li + /Li). [10] In contrast, H-type Nb 2 O 5 (H-Nb 2 O 5 ) owns specific capacity of as high as over 250 mAh g −1 (1.0-3.0 V versus Li + /Li) and a flat charge/discharge Exploring anode materials with fast, safe, and stable Li-(de)intercalation is of great significance for developing next-generation lithium-ion batteries. Monoclinic H-type niobium pentoxide possesses outstanding intrinsic fast Li-(de) intercalation kinetics, high specific capacity, and safety; however, its practical rate capability and cycling stability are still limited, ascribed to the asynchronism of phase change throughout the crystals. Herein this problem is addressed by homogenizing the electron and Li-ion conductivity surrounding the crystals. An amorphous N-doped carbon layer is introduced on the micrometer single-crystal H-Nb 2 O 5 particle to optimize...

No abstract

No abstract

Sodium-ion batteries are considered as a surrogate to conventional lithium-ion batteries for the commercial sector. One of the most auspicious anode materials for sodium-ion batteries is hard carbon. However, its...

No abstract

No abstract

A simple and no-drug resistance antibacterial method was developed by the synthesis of heat-stable and pH-tolerant nisin-loaded iron oxide nanoparticles polydopamine (IONPs@pDA) composites. The composites had a crystal structure and diameters of 25 ± 3 nm, with a saturation magnetization (M s) of 43.7995 emu g–1. Nisin was successfully conjugated onto the IONPs@pDA nanoparticles, as evinced by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses. The novel synthesized material showed good performance in reducing Alicyclobacillus acidoterrestris, a common food spoilage bacterium that represents a significant problem for the food industry. Treatment of A. acidoterrestris cells with composites resulted in membrane damage, as observed by live/dead staining and scanning electron microscopy and transmission electron microscopy analyses. Further, the composites exhibited highly efficient antibacterial activity against cells in only 5 min. Transcriptomic sequencing of culture RNA pools after exposure to composites resulted in a total of 334 differentially expressed genes that were primarily associated with transcriptional regulation, energy metabolism, membrane transporters, membrane and cell wall syntheses, and cell motility. Thus, these results suggested that changes in transcriptional regulation caused by aggregated composites on target cells led to major changes in homeostasis that manifested by decreased energy metabolism, pore formation in the membrane, and repressed cell wall synthesis. Concomitantly, cell motility and sporulation activities were both repressed, and finally, intracellular substances flowed out of leaky cells. The proposed biocontrol method represents a novel means to control microorganisms without inducing drug resistance. Further, these results provide novel insights into the molecular mechanisms underlying the antibacterial activity of composites against microorganisms.

As natural occurring antimicrobial substances, phenolic compounds have been used to inhibit various bacteria. Stenotrophomonas maltophilia 4–1, a strain isolated from food, exhibited spoilage potential in vitro with proteolysis and lipolysis at 25°C. The present study evaluated the antibacterial properties of 13 polyphenols on S. maltophilia 4–1, and selected 6 compounds (ferulic acid, p-coumaric acid, caffeic acid, chlorogenic acid, (−)-epigallocatechin, and phloretin) for binary combination treatments. The results revealed that antibacterial activities of polyphenols were structure-dependent, and cinnamic acid showed strong inhibitory effects, with a minimum inhibitory concentration (MIC) of 0.125 mg/mL. Importantly, we did not observe any obvious synergistic effects across all binary combinations. The antibacterial mechanism of cinnamic acid was related to membrane damage, caused by the loss of cell membrane integrity and alteration of cell morphology. These findings suggest that cinnamic acid is a promising candidate for the control of spoilage bacteria in food.