I came across a document from Nichicon comparing different aluminum electrolytic capacitor technologies which you might find interesting.
In particular, although solid conductive polymer-aluminum capacitors have a number of compelling characteristics, including lower ESR at high frequencies, high ripple current capability, and long life, they have inconsistent self-healing and low resistance to humidity, which makes them more susceptible to short-circuiting. That susceptibility to shorting means that conductive polymer-aluminum caps are not suitable for automotive applications.
However, hybrid polymer-aluminum caps solve the self-healing problem by including a liquid electrolyte, which allows for self-healing, thus solving the shorting issue of standard conductive polymer-aluminum caps, while still retaining many of the advantages of them.
Here’s a link to our offering of hybrid polymer-electrolytic capacitors.
Nichicon paper comparing standard aluminum, polymer-aluminum, and hybrid polymer-aluminum capacitors:
nichicon-hybrids-vs-polymers-vs-aluminums.pdf (377.2 KB)