First-principles study on the electronic structure of a LiFePO4 (0 1 0) surface adsorbed with carbon

Highlights: ► LiFePO4 adsorbed with C are studied by first-principles and experimental method. ► The more stable surface is LiFePO4 (0 1 0) with Li exposed. ► Electrons in Fe-d orbitals play a key role in the microelectronic structure change. ► C-coating restrained the grain growth and improved of the electrochemical properties. ► C reacts with Fe by chemisorption when C is adsorbed on the outermost layer. - Abstract: The electronic structures of a LiFePO4 (0 1 0) surface adsorbed with C are studied by a first-principles method based on DFT. The results show that the system is more stable when the LiFePO4 (0 1 0) surface is cut through Li atoms. PDOS analysis shows that the electronic structure of atoms in the sub-surface is similar to that of atoms in the bulk. The unpaired electrons in Fe-d orbital play a key role in the changes in the microelectronic structure; these changes lower the band gap and generate new bands that favor the transfer of electrons. Atom C reacts with Fe by chemisorptions when C is adsorbed on the outermost layer. Therefore, the materials may have better electrochemical properties by the improvement of diffusion of both electrons and Li ions when limiting the crystal growth with C coating.