Porous Cathodes for Implantable Hybrid Cells

The in vivo power output of implantable power sources using porous platinum- or palladium-black cathodes is approximately four to five times greater than ones using commercially available cathodes of platinum black dispersed in Teflon. Porous electrodes produce a much lower foreign-body reaction than electrodes with plastic binders. Comparison of BET surface-area measurements for the powders and compacted electrodes illustrate that there is an approximate 20-percent decrease in surface area following compaction. The particle size, distribution, and shape of the powders were studied with the aid of scanning electromicrographs. In vitro galvanostatic measurements were made on the implantable power sources to study the electrochemical activity before implantation.