2D Ultrathin Titanium Nitride Nanosheets as Separator Coatings for Li-S Batteries.

Transition metal nitrides (TMNs) are affirmed to be an appealing candidate for boosting the performance of lithium-sulfur (Li-S) batteries due to their excellent conductivity, strong interaction with sulfur species, and the effective catalytic ability for conversion of polysulfides. However, the traditional bulk TMNs are difficult to achieve large active surface area and fast transport channels for electrons/ions simultaneously. Here, a 2D ultrathin geometry of titanium nitride (TiN) is realized by a facile topochemical conversion strategy, which can not only serve as an interconnected conductive platform but also expose abundant catalytic active sites. The ultrathin TiN nanosheets are coated on a commercial separator, serving as a multifunctional interlayer in Li-S batteries for hindering the polysulfide shuttle effect by strong capture and fast conversion of polysulfides, achieving a high initial capacity of 1357 mAh g-1 at 0.1 C and demonstrating a low capacity decay of only 0.046% per cycle over 1000 cycles at 1 C.

Fast Ionic Conducting Hydroxyapatite Solid Electrolyte Interphase Enables Ultra-Stable Zinc Metal Anodes.

Zn metal has been extensively utilized as an anode in aqueous zinc-ion batteries attributed to its affordable cost and superior theoretical capacity. Nevertheless, the presence of dendrites and undesirable side reactions poses challenges to its widespread commercialization. To address these issues, herein, a surface coating composed of hydroxyapatite (HAP) was developed on the Zn anode to create an artificial solid electrolyte interphase. After the application of a hydroxyapatite layer, dendrites and corrosion of the Zn anode are sufficiently inhibited. Furthermore, the hydroxyapatite interphase with a low ionic diffusion barrier enables fast anodic redox kinetics. Consequently, the Zn@HAP symmetric cell possesses a durable lifespan over 2000 h at 1 mA cm-2, while maintaining minimal polarization. Moreover, the practical feasibilities of the Zn@HAP anode are also manifested in full batteries combined with MnO2 cathodes, exhibiting exceptional cycling performance up to 500 cycles at 1 A g-1 and excellent rate capability with a retention of 109 mAh g-1 at 5 A g-1.

[Application of Microbial Fuel Cells in Reducing Methane Emission from Rice Paddy].

We aimed to study whether the methane emission from rice paddy with straw return can be alleviated in microbial fuel cells (MFCs). In our study, the soil mixed with 0. 5% ( mass fraction) rice straw was packed into MFCs reactors, then flooded with excess of sterilized water and transplanted with rice seedlings followed by the operation of MFCs. The MFCs were operated for 98 days covering five stages of seeding, tillering, mid-season aeration, rice filling, and ripening. The voltage data were recorded continuously and in real time during the MFCs operation and the methane emitted was collected once a week using the static chamber method and the methane emission flux was determined by gas chromatography. The results showed that the MFCs current increased and reached the peak value in the seeding and tillering stages and the operation of MFCs significantly reduced the accumulative methane emission in these two stages. The possible reason could be that the electrogens competed with methanogens for organic substrates. The height, the above and below ground biomass, and the productivity of rice plants were not significantly affected by the 98-day operation of MFCs. Our study provides a potential green and sustainable technology for the reduction of CH, emission from rice paddy fields.