02056nas a2200241   4500008004100000022001400041245009200055210006900147260000800216300001600224490000800240520121300248100003801461700002601499700002901525700001801554700003301572700001801605700001501623700002401638700003001662856012201692       2019                        eng d  a0002-786300aImidazole-linked crystalline two-dimensional polymer with ultrahigh proton-conductivity0 aImidazolelinked crystalline twodimensional polymer with ultrahig  cSEP  a14950-149540 v1413 a<p>Proton-exchange membrane fuel cells are promising energy devices for a sustainable future due to green features, high power density, and mild operating conditions. A facile proton-conducting membrane plays a pivotal role to boost the efficiency of fuel cells, and hence focused research in this area is highly desirable. Major issues associated with the successful example of Nafion resulted in the search for alternate proton conducting materials. Even though proton carrier loaded crystalline porous organic frameworks have been used for protonconduction, the weak host-guest interactions limited their practical use. Herein, we developed a crystalline 2D-polymer composed of benzimidazole units as the integral part, prepared by the condensation of aryl acid and diamine in polyphosphoric acid medium. The imidazole linked-2D-polymer exhibits ultrahigh proton conductivity (3.2 X 10(-2) S cm(-1)) (at 95% relative humidity and 95 degrees C) in the pristine state, which is highest among the undoped porous organic frameworks so far reported. The present strategy of a crystalline proton-conducting 2D-polymer will lead to the development of new high performing crystalline solid proton conductor.</p>
1 aRanjeesh, Kayaramkodath, Chandran1 aIlathvalappil, Rajith1 aVeer, Sairam, Dnyaneshwa1 aPeter, Joseph1 aWakchaure, Vivek, Chandrakan1 aGoudappagouda1 aRaj, Vipin1 aKurungot, Sreekumar1 aBabu, Sukumaran, Santhosh  uhttps://library.ncl.res.in/content/imidazole-linked-crystalline-two-dimensional-polymer-ultrahigh-proton-conductivity02618nas a2200253   4500008004100000022001400041245008400055210007000139260000800209490000700217520178600224653001202010653001302022653001902035653001702054653003102071100001802102700002502120700002402145700002002169700003002189700003002219856011502249       2023                        eng d  a1433-785100aIsomer effect on energy storage of π-extended S-shaped double[6]heterohelicene0 aIsomer effect on energy storage of πextended Sshaped double6hete  cNOV0 v623 a<p>Recently, chiral and nonplanar cutouts of graphene have been the favorites due to their unique optical, electronic, and redox properties and high solubility compared with their planar counterparts. Despite the remarkable progress in helicenes, pi-extended heterohelicenes have not been widely explored. As an anode in a lithium-ion battery, the racemic mixture of pi-extended double heterohelical nanographene containing thienothiophene core exhibited a high lithium storage capability, attaining a specific capacity of 424 mAh g-1 at 0.1 A g-1 with excellent rate capability and superior long-term cycling performance over 6000 cycles with negligible fade. As a first report, the pi-extended helicene isomer (PP and MM), with the more interlayer distance that helps faster diffusion of ions, has exhibited a high capacity of 300 mAh g-1 at 2 A g-1 with long-term cycling performance over 1500 cycles compared to the less performing MP and PM isomer and racemic mixture (150 mAh g-1 at 2 A g-1). As supported by single-crystal X-ray analysis, a unique molecular design of nanographenes with a fixed (helical) molecular geometry, avoiding restacking of the layers, renders better performance as an anode in lithium-ion batteries. Interestingly, the recycled nanographene anode material displayed comparable performance. A pi-extended double heterohelical nanographene of thienothiophene core fused with two hexabenzocoronene units exhibits excellent performance as an anode in a lithium-ion battery. The isomer (PP and MM) with more interlayer distance exhibited a high lithium storage capability compared to the other isomer and racemic mixture. Helical nanographene anodes display excellent rate capability, superior long-term cycling performance, and recyclability.image</p>
10aBattery10agraphene10aLi-ion battery10ananographene10aOrganic Electrode Material1 aKumar, Viksit1 aBharathkumar, H., J.1 aDongre, Sangram, D.1 aGonnade, Rajesh1 aKrishnamoorthy, Kothandam1 aBabu, Sukumaran, Santhosh  uhttps://library.ncl.res.in/content/isomer-effect-energy-storage-%CF%80-extended-s-shaped-double6heterohelicene