Downhole tools, systems, and methods for electric-based fracturing are disclosed. A downhole tool for electric-based fracturing may include an outer enclosure, an insulator chamber disposed at least partially within the enclosure, and an electrode disposed at least partially within the insulator chamber. The electrode may extend out from the insulator chamber and the enclosure, and may be configured to transfer electric energy to an exterior environment surrounding the downhole tool. The insulator chamber may be configured to thermally and electrically insulate at least a portion of the electrode from the exterior environment.