Various embodiments concern an electrode of an implantable medical device for delivering electrical stimulation to tissue. Such an electrode can include a main body formed from a substrate metal comprising one of titanium, stainless steel, a cobalt-chromium alloy, or palladium. The main body may not be radiopaque. The electrode may further include a first coating on at least one side of the main body, the first coating comprising a layer of one of tantalum or iridium metal that is at least about 2 micrometers thick. The first coating can be radiopaque and porous. The porosity of the first coating can increase the electrical performance of the electrode in delivering electrical stimulation to tissue.