Twin-Graphene: A Promising Anode Material for Lithium-Ion Batteries with Ultrahigh Specific Capacity

Lithium-ion batteries have long been the focus of energystorage.The potential application of carbon-derived structures as lithium-ionbattery anodes was examined using the first-principles density functionaltheory approach. The results of our calculations revealed that themodified lattice constant, structure, and parameters are similar tothose found in earlier research. It is worth noting that the twin-graphenedouble layer has several stable adsorption sites for lithium. Meanwhile,we discovered that the characteristics of semiconductors of pristinetwin-graphene changed into metal properties after absorbing lithium.From climbing image nudged elastic band calculations, we got a mediumdiffusion barrier of 0.42 eV for lithium ion on twin-graphene, whichdenotes strong diffusivity. Therefore, it has an ultrahigh theoreticalcapacity of 3916 mAh/g, about 5 times that of graphene (744 mAh/g).Twin-graphene double-layer lithium-ion batteries have an average opencircuit voltage of 0.32 V, which ensures long service life and quickcharging in practical applications. The relatively good conductivityand stability of the twin-graphene double layer are further demonstratedthroughout the charge-discharge operation. By reason for theforegoing, twin-graphene double layers will be excellent battery anodesthat can be applied.