Electrical heaters for exhaust aftertreatment systems and assemblies

An electrical heater assembly comprising:

• a heater body comprising a plurality of slots disconnecting portions of the heater body from each other, each slot comprising:
• a first end portion extending from an intersection with an outer periphery of the heater body to a second end portion that terminates within the heater body;
• and
• a receptacle portion located between the first end portion and the second end portion,
• wherein portions of the heater body not disconnected by the plurality of slots form a serpentine current-carrying path through the heater body,
• wherein the first end portion of each slot has a first width, the second end portion of each slot has a second width, and the receptacle portion of each slot has a third width, and
• wherein the third width of the receptacle portion of the slot is larger than both the first width and the second width.