  Electroconvection in rechargeable batteries enhances the growth of dendrites
at the electrode surface. The addition of low molecular weight polymers to the
electrolyte in batteries results in the formation of a thin layer of higher
polymer concentration near the electrode. This is due to van der Waals forces
of attraction between the metal electrode and the polymers dissolved in the
electrolyte. The van der Waals forces act as a restoring body force on the
electrolyte and oppose the growth of perturbations. Using linear stability
analysis, we show that this force opposes electroconvective flow. This
increases the critical voltage required for the onset of electroconvection.
