Lithium−sulfur (Li/S) technology holds great promise for efficient, safe, and economic next-generation batteries. However, commercialization is limited by some issues, which are related to the fast degradation of Li/S cells and poor rate capability. Existing strategies addressing these issues are often unsuitable for commercialization because of their complexity and lack of scalability. This Letter presents a simple, cheap, and scalable synthesis of a sulfur-based cathode material from commercially available poly(methyl methacrylate)/poly-(acrylonitrile) (PMMA/PAN) fibers. Thermal conversion of PMMA/PAN fibers with elemental sulfur yields sulfurized poly(acrylonitrile) (SPAN) with up to 46 wt % covalently bound sulfur. The fibrous morphology with cylindrical macropores helps to form electronic conduction networks in the cathode and provides directed diffusion pathways for ions. Consequently, these Li/SPAN cells show low internal resistances, high initial capacities up to 1672 mAh•g −1 sulfur , high rate capabilities up to 8C, and excellent cycle stabilities over 1200 cycles. In addition, structure and postmortem analysis allow the correlation of electrochemical performance with SPAN's chemical structure.

The flavoenzyme monoamine oxidase (MAO) is essential for the enzymatic decomposition of neurotransmitters. While it is commonly accepted that the rate limiting step of the reaction is the stereoselective abstraction of a hydrogen from the substrate, the precise mechanism is unknown. We modeled the reaction of human MAO-B with benzylamine by means of QM/MM calculations based on density functional theory. Oxidation of the unprotonated substrate was found to proceed with rates in good agreement with experimental values, while the protonated substrate does not react at room temperature. Our results support a concerted asynchronous polar nucleophilic mechanism. The lone pair of the amine-nitrogen interacts with a carbon atom of the flavin cofactor. During the reaction, this lone pair, as well as a proton, are transferred to the cofactor. Analysis of the electronic structure during the reaction rules out a radical mechanism.

Lithium–sulfur (Li/S) batteries are among the most promising next‐generation energy storage systems because of their high theoretical specific energy of ≈2600 Wh kg−1. However, conventional Li/S batteries require high amounts of redox‐inactive liquid electrolytes, which do not contribute to cell capacity. Thus, the practical specific energy of Li/S batteries is often relatively poor (<500 Wh kg−1) and barely competitive with Li‐ion batteries. Herein, a new hybrid Li/S battery that contains both a liquid and a solid cathode, i.e., dimethyl trisulfide (DMTS) and fibrous sulfurized poly(acrylonitrile) (SPAN) as active materials is presented. These Li/DMTS/SPAN cells exhibit high capacity (formally up to 7100 mA h gsulfur of cathode−1), high areal capacity up to 4.3 mA h cm−2, high rate capability up to 8 C, and excellent cycle stability (>700 cycles). In addition, both the working and aging mechanism are elucidated by NMR, Raman, X‐ray photoelectron and electronic impedance spectroscopy, X‐ray powder diffraction, cyclic voltammetry, and postmortem analysis.