High-capacity hydrogen storage in Li-decorated defective penta-BN2: A DFT-D2 study

The high gravimetric density is important for the application of the materials in hydrogen storage. In this study, a defective penta-BN2 monolayer structure (P-BN2) with Li decoration (Li-C1-P-BN2) is proposed for hydrogen storage. The geometric and electronic properties of Li-C1-P-BN2 are studied. Li atoms could be strongly adsorbed on the defective P-BN2 substrate with an average binding energy of 4.168 eV. The Li atoms are committed to the double-sided adsorption of hydrogen molecules. The adsorption energy and capacity of hydrogen on the P-BN2 are significantly enhanced because of the presence of defects and the Li decoration. A high hydrogen gravimetric density of 9.17 wt% is obtained on the Li-C1-P-BN2. The average adsorption energy of hydrogen on the Li-C1-P-BN2 is −0.139 eV. The hydrogen adsorbed system could maintain stable at 300 K. Therefore, the Li-decorated defective P-BN2 material has great potential in the application of hydrogen storage.