High-capacity hydrogen storage in lithium decorated penta-BN2: A first-principles study

Abstract

The development of solid hydrogen storage materials is an important part of the large-scale application of hydrogen energy. The gravimetric density of hydrogen storage materials and modified metal atoms agglomeration are the key research issues in two-dimensional hydrogen storage materials. Based on first-principles calculations, lithium-modified penta-BN2(P-BN2) is developed as a new hydrogen storage material. The geometric and electronic structures of lithium-modified P-BN2 (Li-P-BN2) have been calculated. P-BN2 has strong binding ability to lithium metal atoms, preventing the formation of lithium metal clusters, and the material has a strong stability. Twenty-eight hydrogen molecules can be stably adsorbed by the Li-P-BN2 system, and the theoretical storage gravimetric density of hydrogen is 13.27 wt%. Ab initio molecular dynamics (AIMD) shows that the material has a useable capacity of 8.95 wt% at 300 K. The mean desorption temperature is 437.13 K. The excellent hydrogen adsorption capacity and high gravimetric density of Li-P-BN2 may make it a promising hydrogen storage material.