Pristine and Defective 2D Borophene/Graphene Heterostructure as the Potential Anode of Lithium‐Ion Batteries

Abstract Borophene has received much attention due to its unique structure and electronic properties. However, the application of borophene has been limited by the template effect of the growth metal substrate. A stable borophene/graphene (B/G) heterostructure is designed and prepared by the resonance ball milling method and one‐step molding strategy to realize the application of borophene in the lithium‐ion battery for the first time. Graphene serves as a supporting substrate for borophene, and the B/G anode has a better specific capacity and rate performance than the reduced graphene (G) oxide skeleton. By comparing the electrochemical performance of boron powder samples under different ball milling times, it is found that the anode of B/G heterostructure with 6 h boron powder has the largest specific capacity of 192.3 mAh g –1 , which is 39% higher than that of the graphene framework. Oxidation functional groups on the surface of borophene are beneficial for the rate performance of the anode. And the influence of the surface functional groups of borophene are analyzed on the diffusion performance through the first principles. It is believed that the B/G has potential for further applications in the field of lithium‐ion batteries.