02618nas 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