It is a major challenge to achieve fast charging and high reversible capacity in potassium ion storing carbons. Here, we synthesized sulfur-rich graphene nanoboxes (SGNs) by one-step chemical vapor deposition to deliver exceptional rate and cyclability performance as potassium ion battery and potassium ion capacitor (PIC) anodes. The SGN electrode exhibits a record reversible capacity of 516 mAh g −1 at 0.05 A g −1 , record fast charge capacity of 223 mA h g −1 at 1 A g −1 , and exceptional stability with 89% capacity retention after 1000 cycles. Additionally, the SGN-based PIC displays highly favorable Ragone chart characteristics: 112 Wh kg −1 at 505 W kg −1 and 28 Wh kg −1 at 14618 W kg −1 with 92% capacity retention after 6000 cycles. X-ray photoelectron spectroscopy analysis illustrates a charge storage sequence based primarily on reversible ion binding at the structural−chemical defects in the carbon and the reversible formation of K−S−C and K 2 S compounds. Transmission electron microscopy analysis demonstrates reversible dilation of graphene due to ion intercalation, which is a secondary source of capacity at low voltage. This intercalation mechanism is shown to be stable even at cycle 1000. Galvanostatic intermittent titration technique analysis yields diffusion coefficients from 10 −10 to 10 −12 cm 2 s −1 , an order of magnitude higher than S-free carbons. The direct electroanalytic/analytic comparison indicates that chemically bound sulfur increases the number of reversible ion bonding sites, promotes reaction-controlled over diffusion-controlled kinetics, and stabilizes the solid electrolyte interphase. It is also demonstrated that the initial Coulombic efficiency can be significantly improved by switching from a standard carbonate-based electrolyte to an ether-based one.

6 and C 3 H 8 adsorption capacities compared to HKUST-1 and some other metal− organic frameworks, which reached as high as 6.47 and 7.80 mmol/g at ambient conditions. Its C 2 H 6 /CH 4 and C 3 H 8 /CH 4 adsorption selectivities were up to 12.6 and 173.5, respectively. Fixed-bed experiments showed that 0.3Gly@HKUST-1 could separate the CH 4 /C 2 H 6 /C 3 H 8 mixtures completely at ambient conditions, showing excellent separation property toward the light hydrocarbons. More importantly, stability experiments confirmed that after the two samples were exposed to moist air (RH of 55%) for 20 days, 0.3Gly@HKUST-1 still remained its crystal structure, while parent HKUST-1 lost most of its crystallinity. Computational simulations showed that Gly grafting onto unsaturated Cu site played a critical role in enhancing stability against water vapor and improving capacity due to its shielding of unsaturated Cu site as well as introduction of −COOH or −NH 2 as the H-binding sites. Gly@HKUST-1 is promising for practical application of efficiently recovering ethane and propane from natural gas by adsorption.

Battery separators play a vital role in the safety, sustainability, and electrochemical performance of lithium ion batteries (LIBs). In this work, thermally resistant composite membranes were fabricated by a wet-laid process using northern bleached softwood kraft (NBSK) fibers, polysulfonamide (PSA) fibers, and nanofibrillated cellulose (NFC), for lithium ion battery applications. NFC functioned as a mediator to control and optimize pore size in the composite membranes, while the PSA fibers provided superior heat resistance to the membranes. The as-prepared composite separator membranes have more uniform micropores and superior thermal stability and electrolyte absorption in comparison with a commercial separator membrane (Celgard 2350).

Developing ethane-selective adsorbents is critical for efficient separation and purification of ethylene from the cracked gas, which is a great challenge in the petrochemical industry. Herein, a facile and robust MOF, MIL-53(Al)-FA, was prepared and investigated for its ethylene/ethane separation properties. Singlecomponent ethylene and ethane isotherms of MIL-53(Al)-FA showed a higher ethane capacity than that of ethylene, with an ethane uptake of 3.7 mmol/g at 100 kPa and 1.2 mmol/g at 6.25 kPa (the proportion of ethane in the cracked gas) under 308 K. In addition, its IAST-predicted selectivity for an equimolar ethylene/ ethane mixture was 1.9 at 100 kPa, while a dynamic selectivity of 1.8 could be achieved from breakthrough experiments. The mechanism for preferential adsorption of ethane over ethylene on MIL-53(Al)-FA was further revealed by molecular simulation. The average energies between the adsorbates and the sample were −10 kcal/mol and −8 kcal/mol for ethane and ethylene, respectively, resulting in preferential adsorption of ethane. Thus, MIL-53(Al)-FA is a promising material for efficient separation of ethane from ethylene.

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