02263nas a2200217 4500008004100000022001400041245014400055210006900199260000800268300001600276490000600292520144900298100002701747700001701774700002401791700002801815700002101843700002501864700002401889856013201913 2018 eng d a2168-048500aWater-in-acid gel polymer electrolyte realized through a phosphoric acid-enriched polyelectrolyte matrix toward solid-state supercapacitors0 aWaterinacid gel polymer electrolyte realized through a phosphori cOCT a12630-126400 v63 aA new concept of water-in-acid gel polymer electrolytes (GPEs) is introduced. The simple and scalable UV-light-assisted synthesis of a copolymer matrix possessing polyelectrolyte behavior, followed by swelling in minimally diluted H3PO4 (15.1 M/88 wt % aqueous solution), effects formation of a high proton-conducting, self-standing, and mechanically stable polyelectrolyte GPE (PGPE). Retention of high mechanical stability despite the presence of a large amount of liquid species makes it a promising candidate for replacing conventional GPEs. The high proton conductivity (9.8 X 10(-2) S cm(-1)) of the PGPE at an ambient temperature of 303 K is attributed to the high concentration of the conducting species present in the polymer matrix. The PGPE-based polyaniline (PANI) supercapacitor device (PANI-1) with a mass loading of 1 mg cm(-2) exhibits a high specific gravimetric capacitance of 385 F g(-1) at a current density of 0.25 mA cm(-2). At the same current density, the PANI-5 device retains high gravimetric and areal capacitance values of 258 F g(-1) and 1288 mF cm(-2), respectively. The low equivalent series resistance value of 0.78 Omega (for the PANI-5 device) further proves the excellent electrode-electrolyte interface formed by the water-in-acid GPE. A 100% capacitance retention even after 9000 continuous charge-discharge cycles strongly indicates the feasibility of adopting water-in-acid GPEs in future supercapacitors.1 aVijayakumar, Vidyanand1 aGhosh, Meena1 aTorris, Arun, A. T.1 aChandran, Nikhil, M. K.1 aNair, Sanoop, B.1 aBadiger, Manohar, V.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/water-acid-gel-polymer-electrolyte-realized-through-phosphoric-acid-enriched-polyelectrolyte06517nas a2200205 4500008004100000245012300041210006900164260000800233490000700241520576600248100002806014700002706042700001806069700001706087700002206104700001906126700002406145700002006169856012206189 2019 eng d00aWeak intermolecular interactions in covalent organic framework-carbon nanofiber based crystalline yet flexible devices0 aWeak intermolecular interactions in covalent organic frameworkca cAUG0 v113 a

The redox-active and porous structural backbone of covalent organic frameworks (COFs) can facilitate high-performance electrochemical energy storage devices. However, the utilities of such 2D materials as supercapacitor electrodes in advanced self-charging power-pack systems have been obstructed due to the poor electrical conductivity and subsequent indigent performance. Herein, we report an effective strategy to enhance the electrical conductivity of COF thin sheets through the in situ solid-state inclusion of carbon nanofibers (CNF) into the COF precursor matrix. The obtained COF-CNF hybrids possess a significant intermolecular π···π interaction between COF and the graphene layers of the CNF. As a result, these COF-CNF hybrids (DqTp-CNF and DqDaTp-CNF) exhibit good electrical conductivity (0.25 × 10–3 S cm–1), as well as high performance in electrochemical energy storage (DqTp-CNF: 464 mF cm–2 at 0.25 mA cm–2). Also, the fabricated, mechanically strong quasi-solid-state supercapacitor (DqDaTp-CNF SC) delivered an ultrahigh device capacitance of 167 mF cm–2 at 0.5 mA cm–2. Furthermore, we integrated a monolithic photovoltaic self-charging power pack by assembling DqDaTp-CNF SC with a perovskite solar cell. The fabricated self-charging power pack delivered excellent performance in the areal capacitance (42 mF cm–2) at 0.25 mA cm–2 after photocharging for 300 s.

1 aMohammed, Abdul, Khayum1 aVijayakumar, Vidyanand1 aHalder, Arjun1 aGhosh, Meena1 aAddicoat, Matthew1 aBansode, Umesh1 aKurungot, Sreekumar1 aBanerjee, Rahul uhttps://library.ncl.res.in/content/weak-intermolecular-interactions-covalent-organic-framework-carbon-nanofiber-based02736nas a2200229 4500008004100000022001400041245010700055210006900162260000900231300001400240490000700254520195100261100002702212700001702239700001702256700001402273700002002287700001702307700002402324700002802348856013002376 2024 eng d a2050-748800aWater-chain mediated proton conductivity in mechanically flexible redox-active organic single crystals0 aWaterchain mediated proton conductivity in mechanically flexible cMAR  a5866-58740 v123 a

Investigating electrochemical features of proton-conducting organic crystalline materials is relevant in developing efficient energy storage and conversion devices. However, the poor structural flexibility of the crystalline materials at the molecular level often impedes hydrogen bond reorganization of the proton carriers during proton migration, ultimately leading to low ionic conductivity. Here, we report crystals of azobenzene, functionalized with dipicolylamine at both ends (Azo-DPA), which contain an extended hydrogen-bonding network with water molecules in its structure. Interestingly, the crystals display remarkable mechanical flexibility explicitly probed by the nanoindentation technique. The mechanically flexible neutral organic crystals devoid of any acidic moieties (-COOH, -PO3H2, etc.) within the system, exhibit promising proton conductivity (1.63 x 10-4 S cm-1 at 30 degrees C under 95% relative humidity) which is almost 100 times better compared to the neutral organic systems reported to date. Mechanically flexible redox-active crystalline organic material (Azo-DPA) capable of impressive proton conduction was employed as an electrode material for the first time in an aqueous battery containing Zn2+ ions. The experimental and theoretical studies on the charge storage mechanism revealed the redox activity of the azo (-N 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 N-) centers involving reversible insertion/extraction of protons and Zn2+ ions. Ultimately, the electrode displayed a specific capacity similar to 49 mA h g-1 with almost 100% retention after 1400 cycles, encouraging the scope of redox-active organic crystalline materials for energy storage applications. Investigating the electrochemical features of proton-conducting flexible organic crystalline materials is crucial for the development of efficient energy storage and conversion devices.

1 aHossain, Munshi, Sahid1 aGhosh, Meena1 aMondal, Amit1 aAjmal, P.1 aSaha, Monochura1 aReddy, Malla1 aKurungot, Sreekumar1 aBandyopadhyay, Subhajit uhttps://library.ncl.res.in/content/water-chain-mediated-proton-conductivity-mechanically-flexible-redox-active-organic-single