Language of Lullabies: The Russification and De-Russification of the Baltic States

This article argues that the laws for promotion of the national languages are a legitimate means for the Baltic states to establish their cultural independence from Russia and the former Soviet Union

A Stable Polyaniline-Benzoquinone-Hydroquinone Supercapacitor

A Polyaniline‐Supercapacitor with quinone electrolytes remains stable over 50 000 galvanostatic charge‐discharge cycles. The quinones provide superior stability by preventing the conversion of porous polyaniline to a highly reactive state. Our work shows that highly stable polymer‐supercapacitors can be engineered by combining electrochemically active polymers and redox‐active electrolytes with concerted electrochemical properties

A Stable Polyaniline-Benzoquinone-Hydroquinone Supercapacitor

A Polyaniline‐Supercapacitor with quinone electrolytes remains stable over 50 000 galvanostatic charge‐discharge cycles. The quinones provide superior stability by preventing the conversion of porous polyaniline to a highly reactive state. Our work shows that highly stable polymer‐supercapacitors can be engineered by combining electrochemically active polymers and redox‐active electrolytes with concerted electrochemical properties

A High Capacity Calcium Primary Cell Based on the Ca–S System

Conversion reaction cells afford the ability to explore new energy storage paradigms that transcend the dogma of small, low‐charge cations essential to intercalative processes. Here we report the use of earth‐abundant and green calcium and sulfur in unprecedented conversion reaction Ca–S primary cells. Using S‐infiltrated mesoporous carbon (abbreviated S@meso‐C) cathodes, we achieve discharge capacities as high as 600 mAh g^(−1) (S basis) within the geometry Ca|Ca(ClO_4)_2/CH_3CN|S@meso‐C, at a discharge rate of C/3.5. The electrolyte system in the Ca–S battery is of paramount importance as the solid electrolyte interface (SEI) formed on the Ca anode limits the capacity and stability of the cell. We determine that 0.5 M Ca(ClO_4)_2 in CH_3CN forms an SEI that advantageously breaks down under anodic bias to allow oxidation of the anode. This same SEI, however, exhibits high impedance which increases over time at open circuit limiting the shelf life of the cell

A High Capacity Calcium Primary Cell Based on the Ca–S System

Conversion reaction cells afford the ability to explore new energy storage paradigms that transcend the dogma of small, low‐charge cations essential to intercalative processes. Here we report the use of earth‐abundant and green calcium and sulfur in unprecedented conversion reaction Ca–S primary cells. Using S‐infiltrated mesoporous carbon (abbreviated S@meso‐C) cathodes, we achieve discharge capacities as high as 600 mAh g^(−1) (S basis) within the geometry Ca|Ca(ClO_4)_2/CH_3CN|S@meso‐C, at a discharge rate of C/3.5. The electrolyte system in the Ca–S battery is of paramount importance as the solid electrolyte interface (SEI) formed on the Ca anode limits the capacity and stability of the cell. We determine that 0.5 M Ca(ClO_4)_2 in CH_3CN forms an SEI that advantageously breaks down under anodic bias to allow oxidation of the anode. This same SEI, however, exhibits high impedance which increases over time at open circuit limiting the shelf life of the cell

Sulfur-Functionalized Mesoporous Carbons as Sulfur Hosts in Li–S Batteries: Increasing the Affinity of Polysulfide Intermediates to Enhance Performance

The Li–S system offers a tantalizing battery for electric vehicles and renewable energy storage due to its high theoretical capacity of 1675 mAh g^(–1) and its employment of abundant and available materials. One major challenge in this system stems from the formation of soluble polysulfides during the reduction of S_8, the active cathode material, during discharge. The ability to deploy this system hinges on the ability to control the behavior of these polysulfides by containing them in the cathode and allowing for further redox. Here, we exploit the high surface areas and good electrical conductivity of mesoporous carbons (MC) to achieve high sulfur utilization while functionalizing the MC with sulfur (S–MC) in order to modify the surface chemistry and attract polysulfides to the carbon material. S–MC materials show enhanced capacity and cyclability trending as a function of sulfur functionality, specifically a 50% enhancement in discharge capacity is observed at high cycles (60–100 cycles). Impedance spectroscopy suggests that the S-MC materials exhibit a lower charge-transfer resistance compared with MC materials which allows for more efficient electrochemistry with species in solution at the cathode. Isothermal titration calorimetry shows that the change in surface chemistry from unfunctionalized to S-functionalized carbons results in an increased affinity of the polysulfide intermediates for the S–MC materials, which is the likely cause for enhanced cyclability