Gyroidal Porous Carbon Activated with NH₃ or CO₂ as Lithium−Sulfur Battery Cathodes

Abstract

Ordered mesoporous carbon materials, prepared from co‐assembly of a block copolymer and a commercial resol, were investigated as a sulfur host for LiS‐battery cathodes. We studied two activation methods for such carbons, namely annealing in ammonia (NH3) and carbon dioxide (CO2). We found that both activation environments drastically increased the specific surface area and establish a micro‐ and mesoporous pore structure. Treatment with NH3 also introduced nitrogen groups, which increased the initial specific capacity. The non‐activated carbon yielded carbon/sulfur cathodes with an initial capacity of ∼900 mAh/gsulfur (150 mAh/gsulfur after 100 cycles). The initial capacity was increased to 1300 mAh/gsulfur for the NH3 activated sample but with poor cycling stability. Enhanced performance stability was found for the CO2 treated sample with an initial capacity of 1100 mAh/gsulfur (700 mAh/gsulfur after 100 cycles).

High-Desalination Performance via Redox Couple Reaction in the Multichannel Capacitive Deionization System

“…As the flow rate at the SC increased from 5 to 10 mL/min (at M 100 S 100 , a semi-batch mode), the desalination performance drastically enhanced (12% salt removal to 22% salt removal from the feed concentration of 100 mM NaCl), indicating that the systematic resistance, attributed to the mass transfer, exhibits fundamental role in the desalination performance of MC-RCDI. Not only optimizing the operating condition but also improving the porous structure of the ACC (e.g., increasing the porous size) as well as introducing more effective catalysts (e.g., nanosize electrocatalysts) − could further enhance the desalination performance of the MC-RCDI. Overall, the novel systematic improvement could be considered as one of stepping stones for desalinating highly concentrated feed solutions with further studies.…”

Block copolymers for supercapacitors, dielectric capacitors and batteries

“…High-capacity functional materials usually suffer from high electrical resistance and poor cycling stability, and thus they are integrated with conductive carbons to address their shortcomings. For example, sulfur [157][158][159][160], NiO [161], and Nb 2 O 5 [162] are representative functional materials coupled with block copolymer-derived carbons. The incorporation of the functional materials is achieved by either conversion of preloaded precursors or direct post-infiltration into mesoporous carbons.…”

A Highly Efficient Sulfur Host Enabled by Nitrogen/Oxygen Dual‐Doped Honeycomb‐Like Carbon for Advanced Lithium–Sulfur Batteries

“…Carbon with reasonable structure and heteroatom doping can effectively improve the electrochemical performance of sulfur cathode attributed to the strong covalent bonding to effectively immobilize LiPSs at the molecular level. [ 30 ] There are various methods for doping these atoms into carbon, including surface treatment with different acids, [ 31 ] or under diverse atmospheres, [ 32 ] or the design of a polymer precursor [ 33 ] before carbonization. The latter keeps more advantages because of its controllability and one‐step process.…”