Search for: All records

Abstract Photothermal CO₂reduction 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 CO₂hydrogenation rate of 758 mmol g_cat⁻¹ h⁻¹(2871 mmol g_Co⁻¹ h⁻¹) with a 99.8 % selectivity for CO, three orders of magnitude higher than typical photochemical CO₂reduction reactions. We further demonstrate with this catalyst effective CO₂conversion under natural sunlight one hour before sunset during the winter season, putting forward an important step towards practical solar fuel production. 

Abstract The energetic chemical reaction between Zn(NO₃)₂and Li is used to create a solid‐state interface between Li metal and Li_6.4La₃Zr_1.4Ta_0.6O₁₂(LLZTO) electrolyte. This interlayer, composed of Zn, ZnLi_xalloy, Li₃N, Li₂O, and other species, possesses strong affinities with both Li metal and LLZTO and affords highly efficient conductive pathways for Li⁺transport through the interface. The unique structure and properties of the interlayer lead to Li metal anodes with longer cycle life, higher efficiency, and better safety compared to the current best Li metal electrodes operating in liquid electrolytes while retaining comparable capacity, rate, and overpotential. All‐solid‐state Li||Li cells can operate at very demanding current–capacity conditions of 4 mA cm⁻²–8 mAh cm⁻². Thousands of hours of continuous cycling are achieved at Coulombic efficiency >99.5 % without dendrite formation or side reactions with the electrolyte. 

Abstract This work demonstrates a new approach in using metal organic framework (MOF) materials to improve Li metal batteries, a burgeoning rechargeable battery technology. Instead of using the MIL‐125‐Ti MOF structure directly, the material is decomposed into intimately‐mixed amorphous titanium dioxide and crystalline terephthalic acid. The resulting composite material outperforms the oxide alone, the organic component alone, and the parent MOF in suppressing Li dendrite growth and extending cycle life of Li metal electrodes. Coated on a commercial polypropylene separator, this material induces the formation of a desirable solid electrolyte interphase layer comprising mechanically flexible organic species and ionically conductive lithium nitride species, which in turn leads to Li||Cu and Li||Li cells that can stably operate for hundreds of charging–discharging cycles. In addition, this material strongly adsorbs lithium polysulfides and can also benefit the cathode of lithium–sulfur batteries.