  We demonstrate electrochemical top gating of graphene by using a solid
polymer electrolyte. This allows to reach much higher electron and hole doping
than standard back gating. In-situ Raman measurements monitor the doping. The G
peak stiffens and sharpens for both electron and hole doping, while the 2D peak
shows a different response to holes and electrons. Its position increases for
hole doping, while it softens for high electron doping. The variation of G peak
position is a signature of the non-adiabatic Kohn anomaly at $\Gamma$. On the
other hand, for visible excitation, the variation of the 2D peak position is
ruled by charge transfer. The intensity ratio of G and 2D peaks shows a strong
dependence on doping, making it a sensitive parameter to monitor charges.
