A solid electrolytic capacitor comprising a capacitor element is provided. The capacitor element comprises a sintered porous anode body, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric and that includes conductive polymer particles. The anode body has an exterior surface that spans in a longitudinal direction to define a length of the anode body, wherein at least one channel is recessed into the exterior surface of the anode body. The channel is defined by opposing sidewalls that intersect at a base, wherein the channel has a width of from about 0.4 millimeters to about 3 millimeters and a depth of from about 50 micrometers to about 350 micrometers.