Of the various methods available for the preparation of graphene, thermal exfoliation via the modified Hummer's method provides a low cost, scalable process. However the process has several drawbacks: high temperature processing is required, the quality of the graphene is relatively poor, and chemical reduction is required to reduce the graphene oxide generated by the thermal exfoliation process. Electrochemical exfoliation can be carried out under ambient conditions, and by controlling the exfoliation conditions the properties of the graphene produced can be tuned. In this study we evaluate electrochemical exfoliation in aqueous solution, and in particular investigate the influence of the solution composition on the properties of the synthesized graphene. We find that the salt used influences the quality of the graphene, the surface functionality, thermal stability and the degree of oxidation. Graphene can be produced with a yield of order 65%, with a particle size of order 1 to 10 μm, a high proportion of single layer graphene, and a good electrical conductivity without the need for chemical reduction. Doping of heteroatoms such as nitrogen can be achieved by selecting a suitable salt solution. Furthermore, with a suitable salt a graphene with exceptional thermal stability can be prepared, with minimal mass loss up to 750°C and maintaining good conductivity after prolonged exposure to high temperature.