@article {48939,
	title = {Isomer effect on energy storage of π-extended S-shaped double[6]heterohelicene},
	journal = { Angewandte chemie-international edition},
	volume = {62},
	year = {2023},
	month = {NOV},
	type = {Article},
	abstract = {<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>
},
	keywords = {Battery, graphene, Li-ion battery, nanographene, Organic Electrode Material},
	issn = {1433-7851},
	doi = {10.1002/anie.202311657},
	author = {Kumar, Viksit and Bharathkumar, H. J. and Dongre, Sangram D. and Gonnade, Rajesh and Krishnamoorthy, Kothandam and Babu, Sukumaran Santhosh}
}
@article {49590,
	title = {Heteroatom-synergistic effect on anchoring polysulfides in chalcone-linked nanographene covalent organic frameworks for high-performance Li--S batteries},
	journal = {Advanced Science},
	volume = {12},
	year = {2025},
	month = {APR},
	type = {Article},
	abstract = {<p>
	Lithium-sulfur (Li \&amp; horbar;S) batteries are an attractive option for future energy storage devices because they offer higher theoretical specific capacity, energy density, and cost-effectiveness than commercial lithium-ion batteries. However, the practical applications of Li \&amp; horbar;S batteries are significantly limited by the shuttle effect caused by intermediate lithium polysulfides (LiPSs) and slow redox kinetics. In this study, the molecular engineering of chalcone-linked, sp(2)-bonded nanographene-type covalent organic frameworks (COFs) as sulfur hosts is reported to enhance interactions with LiPSs, thereby effectively suppressing the shuttle effect. The developed sulfur-hosting cathode material demonstrated outstanding battery performance, surpassing most reported materials by achieving a specific capacity of 1228 mA h g(-1) at 0.5C, with 80\% retention after 500 cycles and an average Coulombic Efficiency (C.E.) of 99\%. Additionally, the mechanisms of sulfur immobilization, the subsequent conversion into lithium polysulfides (LiPSs), and their binding energies with COFs are investigated using density functional theory (DFT) calculations. These findings offer valuable insights into the structure-property relationships essential for developing more efficient sulfur-hosting cathodes.</p>
},
	keywords = {anion-pi interaction, covalent organic frameworks, lithium-sulfur battery, nanographene, polysulfide shuttle},
	doi = {10.1002/advs.202415897},
	author = {Ranjeesh, Kayaramkodath Chandran and Javaregowda, Bharathkumar H. and Gaber, Safa and Bhauriyal, Preeti and Kumar, Sushil and Skorjanc, Tina and Finsgar, Matjaz and Heine, Thomas and Krishnamoorthy, Kothandam and Shetty, Dinesh}
}
