Hydrogen‐Bonded Organic Frameworks (HOFs): A New Class of Porous Crystalline Proton‐Conducting MaterialsAvishek Karmakar, Rajith Illathvalappil, Bihag Anothumakkool et al.|Angewandte Chemie International Edition|2016 Two porous hydrogen-bonded organic frameworks (HOFs) based on arene sulfonates and guanidinium ions are reported. As a result of the presence of ionic backbones appended with protonic source, the compounds exhibit ultra-high proton conduction values (σ) 0.75× 10(-2) S cm(-1) and 1.8×10(-2) S cm(-1) under humidified conditions. Also, they have very low activation energy values and the highest proton conductivity at ambient conditions (low humidity and at moderate temperature) among porous crystalline materials, such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs). These values are not only comparable to the conventionally used proton exchange membranes, such as Nafion used in fuel cell technologies, but is also the highest value reported in organic-based porous architectures. Notably, this report inaugurates the usage of crystalline hydrogen-bonded porous organic frameworks as solid-state proton conducting materials.
Novel scalable synthesis of highly conducting and robust PEDOT paper for a high performance flexible solid supercapacitorA scalable method to produce flexible PEDOT/cellulose paper by surfactant-free interfacial polymerization is developed and its application is demonstrated for a flexible solid-state supercapacitor.
<i>In situ</i>polymerization process: an essential design tool for lithium polymer batteriesA comprehensive review article addressing the prospects of the<italic>in situ</italic>polymerization strategy as a tool for surpassing the challenges of electrode|electrolyte interfaces & interphases in lithium polymer batteries.
Sodium Storage and Electrode Dynamics of Tin–Carbon Composite Electrodes from Bulk Precursors for Sodium‐Ion BatteriesAbstract Here, a Sn–C composite material prepared from bulk precursors (tin metal, graphite, and melamine) using ball milling and annealing is reported. The composite (58 wt% Sn and 42 wt% N‐doped carbon) shows a capacity up to 445 mAh g Sn+C −1 and an excellent cycle life (1000 cycles). For the graphite, the ball milling leads to graphene nanoplatelets (GnP) for which the storage mechanism changes from solvent co‐intercalation to conventional intercalation. The final composite (Sn at nitrogen‐doped graphite nanoplatelets (SnNGnP)) is obtained by combining the GnPs with Sn and melamine as the nitrogen source. Rate‐dependent measurements and in situ X‐ray diffraction are used to study the asymmetric storage behavior of Sn, which shows a more sloping potential profile during sodiation and more defined steps during desodiation. The disappearance of two redox plateaus during desodiation is linked to the preceding sodiation current density (memory effect). The asymmetric behavior is also found by in situ electrochemical dilatometry. This method also shows that the effective electrode expansion during sodiation is much smaller (about +14%) compared to what is expected from Sn (+420%), which gives a reasonable explanation for the excellent cycle life for the SnNGnP (and likely other nanocomposites in general). Next to the advantages, challenges, which result from the nanocomposite approach, are also discussed.
Tuning of multiple luminescence outputs and white-light emission from a single gelator molecule through an ESIPT coupled AIEE processArunava Maity, Firoj Ali, Hridesh Agarwalla et al.|Chemical Communications|2014 A unique example of an ESIPT coupled AIEE process, associated with a single molecule (1), is utilized for generating multiple luminescent colors (blue-green-white-yellow). The J-aggregated state of 1 forms a luminescent gel in THF and this luminescent property is retained even in the solid state.