Electrospray of room temperature ionic liquids (RTILs), which are solvent-free electrolytes with easily tailored ions, is emerging as a powerful tool in diverse fields. In particular, electrosprays of RTILs operating in the pure-ion mode have attracted significant attention recently. However, despite intensive technological development, these electrosprays have yet to achieve the robustness and effectiveness demanded by their applications. Mechanisms behind these electrosprays remain poorly understood.