An implantable device, such as a pacer, defibrillator, or other cardiac rhythm management device, can include one or more MRI Safe components. In an example, the implantable device includes a battery including a first electrode and a second electrode separate from the first electrode. The second electrode includes a first surface and a second surface. The second electrode includes a slot through the second electrode from the first surface toward the second surface. The slot extends from a perimeter of the second electrode to an interior of the second electrode. The slot is configured to at least partially segment a surface area of the second electrode to reduce a radial current loop size in the second electrode.