Polymer electrolytes constitute a promising class of materials for rechargeable Li-batteries. The ionic conductivity behavior is dependent on the local morphology of the material, which in turn is dependent on the polymer host composition, salt content and temperature. We have synthesized novel polymer host materials – consisting of comb-shaped polymers in a block-copolymer arrangement – which have been investigated as electrolytes in prototype battery cells. To fully understand the electrochemical behavior of these systems, we need to understand how their morphology interplay with salt concentration and temperature. We therefore propose to investigate the polymer nano-structure by Small Angle Neutron Scattering (SANS).