Dirac Nodal Line Semimetal of Three-Dimensional Cross-Linked Graphene Network as Anode Materials for Li-Ion Battery beyond Graphite

Li-ion batteries (LIBs) are common commercial rechargeable batteries with wide application. One of the huge challenges for LIBs is to find the high capacity anode materials. In this work, by employing first-principles calculations, we design a three-dimensional (3D) porous carbon honeycomb material by a cross-linked graphene sheet, named Immm-C16. It exhibits low energy and is thermally, dynamically, and mechanically stable. Immm-C16 possesses a unique electronic band structure with a Dirac line and exhibits a high Fermi velocity of 1.10 × 106 m s–1. More importantly, the high theoretical capacities of 557.87 mAh/g, low diffusion barriers of 0.0055 eV, the average voltages of 0.40 V, and small volume changes of 2.9% suggest that semimetallic Immm-C16 is a promising anode material in LIBs. Such excellent properties provide Immm-C16 with fast charge/discharge rates and longer cycling performance as an anode material for LIBs. Our study not only expands the family of 3D carbon honeycomb materials with extraordinary properties but also may open up an application for the next generation of LIBs as an anode material.