Elucidating the Role of Rational Separator Microstructures in Guiding Dendrite Growth and Reviving Dead Li.

Li metal has attracted considerable attention as the preferred anode material for high-energy batteries. However, Li dendrites have limited the development of Li-metal batteries. Herein, the effects of tuning the porous separator microstructure (SM) for guiding Li dendrite growth and reviving dead Li are revealed using a mechano-electrochemical phase-field model. A strategy of guiding, instead of suppression, was applied to avoid disordered Li dendrite growth. By analyzing the effects of the number of layers, thickness, degree of staggered overlap in the separator, interlayer spacing, and porosity of SM on Li dendrite behavior, we discovered that applying a rationally designed SM can finely guide the Li nucleation and growth direction toward dense deposition. The revival of dead Li was also observed via an in situ experiment on Li dendrites. The reactivation of dead Li after it recontacts Li metal was verified. These findings not only provide fundamental information for the tuning of the SM but can also help better understand the dendrite growth of other alkali metal-ion batteries.

Studying antibiotic-membrane interactions via X-ray diffraction and fluorescence microscopy.

Antibiotic drug resistance is a serious issue for the treatment of bacterial infection. Understanding the resistance to antibiotics is a key issue for developing new drugs. We used penicillin and sulbactam as model antibiotics to study their interaction with model membranes. Cholesterol was used to target the membrane for comparison with the well-known insertion model. Lamellar X-ray diffraction (LXD) was used to determine membrane thickness using successive drug-to-lipid molar ratios. The aspiration method for a single giant unilamellar vesicle (GUV) was used to monitor the kinetic binding process of antibiotic-membrane interactions in an aqueous solution. Both penicillin and sulbactam are found positioned outside the model membrane, while cholesterol inserts perpendicularly into the hydrophobic region of the membrane in aqueous solution. This result provides structural insights for understanding the antibiotic-membrane interaction and the mechanism of antibiotics.