Electrolytic capacitor having an anode formed from a tantalum powder with a relatively low specific charge

An electrolytic capacitor for use in an implantable medical device, the electrolytic capacitor comprising:

• a) a casing;
• b) at least one tantalum anode housed in the casing, the at least one tantalum anode comprising an anodically oxidized pellet formed from a pressed and sintered tantalum powder of agglomerated tantalum particles, wherein the at least one tantalum anode is characterized as having been formed to a voltage that ranges from 310 volts to about 430 volts, and wherein the tantalum powder has:
• i) tantalum particles with an aspect ratio of about 1 to about 2;
• ii) tantalum particles with sinter necks having a thickness that ranges from about 200 nanometers to about 1,100 nanometers;
• iii) a specific charge that ranges from about 9,000 μF*V/g to about 11,000 μF*V/g, and
• iv) wherein the at least one tantalum anode has a breakdown voltage that ranges from about 340 volts to about 450 volts;
• c) a lead wire that extends from the at least one tantalum anode to outside the casing, the lead wire being electrically isolated from the casing;
• d) a cathode comprising a cathode material coated on at least one inner surface of the casing or coated on a conductive substrate electrically connected to the casing, the cathode material facing the at least one tantalum anode;
• e) a separator positioned between the at least one tantalum anode and the cathode;
• and
• f) a fluidic working electrolyte contained in the casing in contact with the at least one tantalum anode and the cathode.