First-principles identification of interface effect on Li storage capacity of C3N/graphene multilayer heterostructure

The design and development of new and light weight two-dimensional (2D) heterostructures as anode materials to enhance the electrochemical properties for Li-ion batteries (LIB's) is a challenge. In this work, using first-principles study, we have demonstrated that the ratio of two-dimensional polyaniline (C3N) and graphene in the multilayer heterostructures plays a major role to define the Li storage properties and to provide metallicity for easy conduction of electrons. We have found that charge transfer between Li and the host depends on the interface and site, which helps in the improvement in specific capacity. The proposed heterostructures shows specific capacity varies from 558 mAh/gm to 423 mAh/gm. The specific capacity is high for heterostructures with more graphene in ratio which is correlated to higher charge accumulation in the host. Also, graphene helps to minimize the open-circuit voltage (OCV) of C3N and maintained an average of 0.4 V. The volume expansion for fully lithiated heterostructures is within 22 %. Li diffusion barrier energy varies in the range of 0.57 to 0.25 eV. The proposed 2D heterostructures could be a future material for anode in LIB's and the description of the interface effect on Li storage properties will help for further development of 2D heterostructure materials. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

The ratio of C3N and graphene in multilayer heterostructures plays a significant role in defining Li-ion battery performance, with higher graphene content leading to increased specific capacity. The proposed 2D heterostructures show promise as future anode materials for LIB's, with implications for further development in the field.