S1 Supporting Information Strain Engineered Blue P-MoS 2 van der Waals Heterostructure with Improved Lithiation/Sodiation for LIBs and SIBs Gayatree Barik, 1 and Sourav Pal 1,2 * 1 Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India 2 Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India Email: s.pal@iiserkol.ac.in Fig. S1 Schematic views of the charge density difference of single Li (top line) and Na (bottom line) adsorption on unstrained Blue P-MoS 2 heterostructure. Adsorption on the out-surface of MoS 2 (left); Adsorption at the interlayer of Blue P and MoS 2 (middle) and Adsorption on the out-surface of phosphorene (right). The loss of electrons is indicated in pink and gain of electrons is indicated in blue colour. Fig. S2 Schematic views of the charge density difference of single Li (top line) and Na (bottom line) adsorption on Blue P-MoS 2 heterostructure at 10% Tensile strain. Adsorption on the out- surface of MoS 2 (left); Adsorption at the interlayer of Blue P and MoS 2 (middle) and Adsorption on the out-surface of phosphorene (right). The loss of electrons is indicated in pink and gain of electrons is indicated in blue colour. Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is © the Owner Societies 2019