Electric field enhances the electronic and diffusion properties of penta-graphene nanoribbon anodes in lithium-ion batteries†
Abstract
Enhancement of the ionic conductivity and reduction of diffusion barriers of lithium-ion batteries are crucial for improving the performance of the fast-growing energy storage devices. Recently, the fast-charging capability of commercial-like lithium-ion anodes with the smallest modification of the current manufacturing technology has been of great interest. We used first principles methods computations with density functional theory and the climbing image-nudged elastic band method to evaluate the impact of an external electric field on the stability, electronic band gap, ionic conductivity, and lithium-ion diffusion coefficient of penta-graphene nanoribbons upon lithium adsorption. By adsorbing a lithium atom, these semiconductor nanoribbons become metal with a formation energy of −0.22 eV, and an applied electric field perpendicular to the surface of these nanoribbons further stabilizes the structure of these lithium-ion systems. Using the Nernst–Einstein relation, in the absence of an electric field, the ionic conductivity of these penta-graphene nanoribbons amounts to 1.24 × 10−4 S cm−1. In the presence of an electric field, this conductivity can reach a maximum value of 8.89 × 10−2 S cm−1, emphasizing the promising role of an electric field for supporting fast-charging capability. Our results highlight the role of an external electric field as a novel switch to improve the efficiency of lithium-ion batteries with penta-graphene nanoribbon electrodes and open a new horizon for the use of pentagonal materials as anode materials in the lithium-ion battery industry.