Calculations of the stabilization energies for Li+ ions in poly(ethylene oxide)-based solid electrolytes

Structures are simulated for solid electrolytes based on poly(ethylene oxide) (PEO) and a PEO/branched-PEO copolymer, each containing 5% lithium perchlorate per oxygen atom. The Coulomb interaction energy for the lithium ions and the change in the polarization energy upon adding a lithium ion are calculated to give the total electrostatic stabilization energies for Li+ in the electrolyte, taking account of the permanent dipoles on the polymer segments. The Coulomb energy and the polarization energy per lithium ion act in opposite senses to give the total stabilization energy. For each electrolyte the stabilization energy distribution is centered at about − 5 eV with a half width of approximately 3 eV, indicating that branching does not affect the lithium ion energies significantly. The results are of use in simulations of ion transport.