The need for creating safe electrolytes for lithium batteries is significant given the continued safety problems associated with current lithium-ion batteries. Nonflammable polymer electrolytes offer a possible solution but the rate of lithium ion transport is too low for practical applications. In this talk, I will discuss some of the fundamental factors that limit ion transport in polymers. In all electrolytes, the current generated at steady state is proportional to the applied potential. The proportionality constant depends on Stefan-Maxwell diffusion coefficients that are negative over a substantial salt concentration range. The implications of this on battery performance is discussed.