N-Rich Bilayer Solid Electrolyte Interphase toward Highly Reversible Lithium Metal Batteries.

Continuous lithium (Li)/electrolyte interfacial reactions and uncontrollable Li dendrites severely hamper the application of paradigmatic Li metal batteries (LMBs). Aiming to address the above-mentioned crucial issues, N-rich polymer-inorganic bilayers at the Li/electrolyte interface are designed via nitrate-rich electrolytes, achieving high-energy-density and long-lifespan LMBs. The inner layer of Li3N favors rapid and uniform Li+ deposition, while the outer layer of N-containing flexible polymers facilitates uniform Li+ distribution at the interlayer and accommodates volume changes during cycling. The synergistic effect of N-rich polymer-inorganic bilayers promotes the formation of dense uniform spherical nuclei morphology instead of dendrites, thus significantly improving the plating-stripping reversibility of LMBs. Attributed to the unique interphase, the Li|Li cell can stably run for over 1000 h at 1.0 mA cm-2 with an even deposition morphology, which is monitored and proven by in situ optical microscopy. Moreover, the assembled Li|S cell displays a high capacity of 697.6 mA h g-1 for over 150 cycles and a 99% Coulombic efficiency. This work paves the way for designing high-energy and long-lifespan LMBs.

Highly Efficient Thermal Energy Storage Using a Hybrid Hypercrosslinked Polymer*.

In this work, an organic/inorganic hybrid polymer containing siloxyl functional groups was synthesized and applied to encapsulate phase change materials (PCMs). Owing to the mild conditions of the hypercrosslinking reaction, which only requires the addition of a catalytic amount of aqueous alkaline solution, both organic and inorganic PCMs are tolerated. It is noteworthy that the initial homogeneous state of the reaction mixture allowed the ultimate encapsulation rate of the PCMs and the uniform blending of the third nano-additives with the aim of thermal conductivity enhancement. Further study reveals that the presence of this hybrid hydrophobic polymer in a phase change composite endows the latter with a unique self-cleaning property. This novel PCM encapsulation protocol is suitable for nanoparticles including carbon-based nanomaterials, metal oxide nanoparticles, and inorganic oxide nanoparticles. A thermal conductivity enhancement of 600 % was achieved along with 93.7 % light-to-thermal conversion efficiency with a latent heat of 180 J g-1 without leakage.

In-situ synthesis of Fe7S8 nanocrystals decorated on N, S-codoped carbon nanotubes as anode material for high-performance lithium-ion batteries.

Fe7S8 has emerged as an attractive anode material for lithium-ion batteries (LIBs) due to its outstanding features such as low cost, high theoretical capacity, as well as environmental benignity. However, the rapid capacity fading derived from the tremendous volume change during the charging/discharging process hinders its practical application. Nanostructure engineering and the combination with carbonaceous material are essential to address this issue. In this work, Fe7S8 nanocrystals decorated on N, S-codoped carbon nanotubes (Fe7S8-NSC) were synthesized through a facile one-step pyrolysis of Fe-containing polypyrrole (PPy) nanotubes with sulphur powders under nitrogen atmosphere. When evaluated as anode of LIBs, Fe7S8-NSC demonstrates excellent cycling stability (718.8 mAh g-1 at 100 mA g-1 after 100 cycles) and superior rate ability (290.8 mAh g-1 at 2000 mA g-1). Moreover, Fe7S8-NSC shows a typical specific capacity recovery phenomenon, an extraordinary capacity of 744.4 mAh g-1 at 2000 mA g-1 after 1000 cycles can be achieved, which outperforms most of the Fe7S8-based anode materials reported before. The Fe7S8-NSC should be a promising anode material for high-performance LIBs.

Enhanced photo-H2 production by unsaturated flow condition in continuous culture.

A biofilm photobioreactor under unsaturated flow condition (BFPBR-U) is proposed using a polished optical fiber as the internal light source for photo-H2 production in continuous culture. The main chamber was filled with spherical glass beads to create the reaction bed and the cells were immobilized to form a biofilm under unsaturated flow condition obtained by pumping substrate solution over a packing bed at a rate to create a thin fluid film and injecting the argon to maintain the gas phase space. The effects of operational conditions, including flow rate and influent substrate concentration, on the photo-H2 production performance were investigated. The unsaturated flow conditions eliminated the inhibition caused by high organic loading rate and enhanced light transmission efficiency, leading to an improvement in the photo-H2 production performance.