High-Mass-Loading Li-S Batteries Catalytically Activated by Cerium Oxide: Performance and Failure Analysis under Lean Electrolyte Conditions.

Increasing sulfur mass loading and minimizing electrolyte amount remains a major challenge for the development of high-energy-density Li-S batteries, which needs to be tackled with combined efforts of materials development and mechanistic analysis. This work, following the same team's most recent identification of the potential-limiting step of Li-S batteries under lean electrolyte conditions, seeks to advance the understanding by extending it to a new catalyst and into the high-sulfur-mass-loading region. CeOx nanostructures are integrated into cotton-derived carbon to develop a multifunctional 3D network that can host a large amount of active material, facilitate electron transport, and catalyze the sulfur lithiation reaction. The resulting S/CeOx /C electrode can deliver a stable areal capacity of 9 mAh cm-2 with a high sulfur loading of 14 mg cm-2 at a low electrolyte/sulfur ratio of 5 µL mg-1 . This study discovers that Li||S/CeOx /C cells usually fail during charging at high current density, as a consequence of local short circuiting caused by electrochemically deposited Li dendrites penetrating through the separator, a previously overlooked failure pattern distinctive to cells operating under lean electrolyte conditions. This work highlights the importance of developing new material structures and analyzing failure mechanisms in the advancement of Li-S batteries.

Solar-Driven CO2 Conversion via Optimized Photothermal Catalysis in a Lotus Pod Structure.

Photothermal CO2 reduction is one of the most promising routes to efficiently utilize solar energy for fuel production at high rates. However, this reaction is currently limited by underdeveloped catalysts with low photothermal conversion efficiency, insufficient exposure of active sites, low active material loading, and high material cost. Herein, we report a potassium-modified carbon-supported cobalt (K+ -Co-C) catalyst mimicking the structure of a lotus pod that addresses these challenges. As a result of the designed lotus-pod structure which features an efficient photothermal C substrate with hierarchical pores, an intimate Co/C interface with covalent bonding, and exposed Co catalytic sites with optimized CO binding strength, the K+ -Co-C catalyst shows a record-high photothermal CO2 hydrogenation rate of 758 mmol gcat -1 h-1 (2871 mmol gCo -1 h-1 ) with a 99.8 % selectivity for CO, three orders of magnitude higher than typical photochemical CO2 reduction reactions. We further demonstrate with this catalyst effective CO2 conversion under natural sunlight one hour before sunset during the winter season, putting forward an important step towards practical solar fuel production.

Optimization and Evaluation of Hydration Method for Cold Recovery of Oils and Defatted Meal from Pinus armandi Seed Kernels.

Large quantities of oils and proteins are demanded per year while their production needs environmentally friendly (green), safe, low cost, efficient and sustainable methods. Hydration method for producing Pinus armandi seed kernel oil and defatted meal rich in proteins was therefore developed, which had the following optimal conditions: baking kernels at 130 °C for 10 min, grinding them to pass through a 80-mesh sieve, mixing the ground kernel (10.00 g) with 1.00 mL of 8% brine or water and agitating at room temperature for 30 min. This method recovered 96.71% edible oil with vitamin E and K, phytosterols, carotenoids and squalene concentrated and de-oiled meal containing 57.98% proteins and 4.17% oils with ascorbic acid, thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, folate, total phenolic and flavonoids concentrated. It had higher recovery rate and other physicochemical indices of edible oil and was found to be more sustainable as compared with cold pressing, enzyme-assisted aqueous extraction and solvent extraction.

Free-Standing Crystalline@Amorphous Core-Shell Nanoarrays for Efficient Energy Storage.

Structures comprising high capacity active material are highly desirable in the development of advanced electrodes for energy storage devices. However, the structure degradation of such material still remains a challenge. The construction of amorphous and crystalline heterostructure appears to be a novel and effectual strategy to figure out the problem, owing to the distinct properties of the amorphous protective layer. Herein, crystalline-Co3 O4 @amorphous-TiO2 core-shell nanoarrays directly grown on the carbon cloth substrate are rationally designed to construct the free-standing electrode. In the unique structure, the 3D porous nanoarrays provide increased availability of electrochemical active sites, and the array with a unique heterostructure of crystalline Co3 O4 core and amorphous TiO2 shell exhibits intriguing synergistic properties. Besides, the amorphous TiO2 protective layer shows elastic behavior to mitigate the volume effect of Co3 O4 . Benefiting from these structural advantages, the as-prepared free-standing electrode exhibits superior lithium storage properties, including high coulombic efficiency, outstanding cyclic stability, and rate capability. Pouch cells with high flexibility are also fabricated and show remarkable electrochemical performances, holding great potential for flexible electronic devices in the future.