02617nas a2200253   4500008004100000022001400041245008400055210007000139260000800209490000700217520178600224653001202010653001302022653001902035653001702054653003102071100001802102700002502120700002402145700002002169700003002189700003002219856011402249       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  uhttp://library.ncl.res.in/content/isomer-effect-energy-storage-%CF%80-extended-s-shaped-double6heterohelicene02229nas a2200217   4500008004100000022001400041245010100055210006900156260000900225490000700234520148200241653001601723653001301739653001901752653001901771653001701790100002301807700002501830700003001855856012601885       2023                        eng d  a2196-021600aLinear polymer comprising dual functionalities with hierarchical pores for lithium ion batteries0 aLinear polymer comprising dual functionalities with hierarchical  cOCT 0 v103 a<p>Organic materials with carbonyl, azo, nitrile and imine moieties are widely used in lithium batteries. The solubility of these materials in battery electrolytes is an issue. Aggregation of the organic molecules can suppress the solubility, but the accessibility of lithium-ion is hindered. Therefore, insoluble porous organic materials are desired. Herein, we synthesized a linear polymer with carbonyl and azo functionalities. Due to the presence of easily isomerizable azo moiety, a porous polymer was obtained. The polymer showed nano and micropores. The battery with the porous polymer showed an impressive specific capacity of 400 mA h/g at 0.2 A/g. If the battery is pre-conditioned, the specific capacity increased to 615 mA h/g at the same current density. The post-mortem analysis of the battery confirmed that the polymer didn't dissolve in the battery electrolyte. The control material is a small molecule with carbonyl and azo moieties that showed a poor specific capacity of 40 mA h/g indicating the necessity to have a hierarchically porous dual-functional polymer. Polymers for batteries: A linear polymer with micro and Nano pores with azo and carbonyl functionalities renders increased accessibility to Li ions after preconditioning. During charge-discharge experiment Azo-Carb-PDI electrode had impressive discharge capacity of 469 mA h/g after 500 cycle which is almost 15 times higher than the monomer (Azo-PDI-Azo, 30 mA h/g after 100 cycle).image</p>
10aazo polymer10acarbonyl10aLi-ion battery10aporous polymer10aRylene-imide1 aAher, Jagadish, D.1 aPalani, Sathishkumar1 aKrishnamoorthy, Kothandam  uhttp://library.ncl.res.in/content/linear-polymer-comprising-dual-functionalities-hierarchical-pores-lithium-ion-batteries