Stable Harsh-Temperature Lithium Metal Batteries Enabled by Tailoring Solvation Structure in Ether Electrolytes.

For lithium metal batteries (LMBs), the elevated operating temperature results in severe capacity fading and safety issues due to unstable electrode-electrolyte interphases and electrolyte solvation structures. Therefore, it is crucial to construct advanced electrolytes capable of tolerating harsh environments to ensure stable LMBs. Here, we proposed a stable localized high-concentration electrolyte (LHCE) by introducing the highly solvating power solvent diethylene glycol dimethyl ether (DGDME). Computational and experimental evidence discloses that the original DGDME-LHCE shows favorable features for high-temperature LMBs, including high Li+-binding stability, electro-oxidation resistance, thermal stability, and nonflammability. The tailored solvated sheath structure achieves the preferred decomposition of anions, inducing the stable (cathode and Li anode)/interphases simultaneously, which enables a homogeneous Li plating-stripping behavior on the anode side and a high-voltage tolerance on the cathode side. For the Li||Li cells coupled with DGDME-LHCE, they showcase outstanding reversibility (a long lifespan of exceeding 1900 h). We demonstrate exceptional cyclic stability (∼95.59%, 250 cycles), high Coulombic efficiency (>99.88%), and impressive high-voltage (4.5 V) and high-temperature (60 °C) performances in Li||NCM523 cells using DGDME-LHCE. Our advances shed light on an encouraging ether electrolyte tactic for the Li-metal batteries confronted with stringent high-temperature challenges.

Kinetics-Driven MnO2 Nanoflowers Supported by Interconnected Porous Hollow Carbon Spheres for Zinc-Ion Batteries.

For rechargeable aqueous zinc-ion batteries (ZIBs), manganese dioxide is one of the most promising candidates as a cathode material because of its cost effectiveness, eco-friendliness, and high specific capacities. However, the ZIBs suffer from poor rate performance and low cycle life due to the weak intrinsic electronic conductivity of manganese dioxide, poor ion diffusion of lump manganese dioxide, and its volumetric expansion during the cycle. Herein, we prepare MnO2@carbon composites (MnO2@IPHCSs) by in situ growing MnO2 nanoflowers on an interconnected porous hollow carbon spheres (IPHCSs) template. IPHCSs, as excellent conductors, significantly improve the conductivity of the manganese dioxide cathode. The hollow porous carbon framework of IPHCSs can offer more ion diffusion paths to internal MnO2@IPHCS carbon composites and acts as a buffer room to cope with the drastic volume contraction and expansion during charge/discharge cycling. The rate performance tests show that MnO2@IPHCSs with high conductivity have a specific capacity of 147 mA h g-1 at 3 C. MnO2@IPHCSs with hollow and nanoflower structures are shown to have excellent ion diffusion performance (ion diffusion coefficient = 10-11 to 10-10 cm2 s-1) in the electrochemical kinetics of the galvanostatic intermittent titration technique. Long cycle performance testing and in situ Raman characterization reveal that MnO2@IPHCSs have high cycling stability (85.5% capacity retention after 800 cycles) and reversibility due to the enhanced structure and increased conductivity. The excellently conductive manganese dioxide supported by IPHCSs has good rate and cycling performance, which can be used to produce superior-performance ZIBs.

Ultra-stable Li||LiFePO4 batteries via advanced designing of localized high concentration electrolyte.

The High-Performance Li-LiFePO4 batteries (Li||LFP) realized by highly compatible electrolytes are considered to be the breakthrough point to achieve the stability and high energy density of lithium-ion battery (LIB) systems. However, the current prevailing commercial electrolytes can hardly be compatible with both LFP cathode and lithium anode simultaneously to an ideal extent. On this very note, we designed an advanced ether-based localized high concentration electrolyte (abbreviated as "ADE"), which exhibits extreme compatibility with LFP-based lithium metal batteries (Fb-LMBs). Equipped with ADE-electrolyte, the Li||LFP coin cell system can carry out more than 4000 fast-charging/discharging (3C for charge and 6C for discharge, respectively) rigorously cycles. Each cycle can not only sacrifice just 0.145‱ capacity on average compared with the original value, but also cycle at elevated temp (>200 fast charging/discharging cycles under 60 °C). This performance remains rare in liquid electrolyte systems in previous reports. The significantly enhanced electrochemical performance can be ascribed to the stabilization of both LFP-cathode/electrolyte and Li-metal-anode/electrolyte interphases. In addition, due to its specific solvated sheath structure, its wettability and flame-retarding properties are superior to those of the control group. This work expands the space for designing a stable fast-charge LFP-based system and sheds light on the possibility of replacing the most popular graphite||LFP system with Li ||LFP configuration with high energy density and stable cyclic performance.

Phenanthrene Antibiotic Targets Bacterial Membranes and Kills Staphylococcus aureus With a Low Propensity for Resistance Development.

New classes of antibiotics with different mechanisms of action are urgently required for combating antimicrobial resistance. Blestriacin, a dihydro-biphenanthrene with significant antibacterial activity, was recently isolated from the fibrous roots of Bletilla striata. Here, we report the further characterization of the antimicrobial potential and mode of action of blestriacin. The phenanthrene compound inhibited the growth of all tested clinical isolates of Staphylococcus aureus including methicillin-resistant S. aureus (MRSA). The minimum inhibitory concentrations (MICs) of blestriacin against these pathogens ranged from 2 to 8 µg/mL. Minimum bactericidal concentration (MBC) tests were conducted, and the results demonstrated that blestriacin was bactericidal against S. aureus. This effect was confirmed by the time-kill assays. At bactericidal concentrations, blestriacin caused loss of membrane potential in B. subtilis and S. aureus and disrupted the bacterial membrane integrity of the two strains. The spontaneous mutation frequency of S. aureus to blestriacin was determined to be lower than 10-9. The selection and whole genome sequencing of the blestriacin -resistant mutants of S. aureus indicated that the development of blestriacin resistance in S. aureus involves mutations in multi-genes. All these observations can be rationalized by the suggestion that membrane is a biological target of blestriacin.

Endogenous Production of n-3 Polyunsaturated Fatty Acids Promotes Fracture Healing in Mice

Bone fracture is a global healthcare issue for high rates of delayed healing and nonunions. Although n-3 polyunsaturated fatty acid (PUFA) is considered as a beneficial factor for bone metabolism, only few studies till date focused on the effects of n-3 PUFAs on fracture healing. In this study, we investigated the effect of endogenous n-3 PUFAs on fracture healing by measuring femur fracture repair in both fat-1 transgenic mice and WT mice. Proximal femoral fracture model was established in fat-1 transgenic mice and WT mice, respectively, and then the fracture was analyzed by using X-ray, micro-computed tomography (micro-CT), and histological assessment at 7, 14, 21, 28, and 35 days after fixation. The results showed that compared with WT mice, fat-1 mice exhibited acceleration in fracture healing through radiographic and histological analysis (18­21 days versus 21­28 days postfracture). Meanwhile, X-ray and micro-CT analysis that showed better remodeling callus formation were in the fat-1 group compared to WT group. Furthermore, histological analysis revealed that endogenous n-3 PUFAs promoted local endochondral ossification and accelerated the remodeling of calcified calluses after fracture. In conclusion, the present study indicated that endogenously produced n-3 PUFAs promote fracture healing process and accelerate bone remodeling in mice, and supplementation of n-3 PUFAs was positively associated with fracture healing.

Endogenous Production of n-3 Polyunsaturated Fatty Acids Promotes Fracture Healing in Mice.

Bone fracture is a global healthcare issue for high rates of delayed healing and nonunions. Although n-3 polyunsaturated fatty acid (PUFA) is considered as a beneficial factor for bone metabolism, only few studies till date focused on the effects of n-3 PUFAs on fracture healing. In this study, we investigated the effect of endogenous n-3 PUFAs on fracture healing by measuring femur fracture repair in both fat-1 transgenic mice and WT mice. Proximal femoral fracture model was established in fat-1 transgenic mice and WT mice, respectively, and then the fracture was analyzed by using X-ray, micro-computed tomography (micro-CT), and histological assessment at 7, 14, 21, 28, and 35 days after fixation. The results showed that compared with WT mice, fat-1 mice exhibited acceleration in fracture healing through radiographic and histological analysis (18-21 days versus 21-28 days postfracture). Meanwhile, X-ray and micro-CT analysis that showed better remodeling callus formation were in the fat-1 group compared to WT group. Furthermore, histological analysis revealed that endogenous n-3 PUFAs promoted local endochondral ossification and accelerated the remodeling of calcified calluses after fracture. In conclusion, the present study indicated that endogenously produced n-3 PUFAs promote fracture healing process and accelerate bone remodeling in mice, and supplementation of n-3 PUFAs was positively associated with fracture healing.