The main difference between aluminum polymer capacitors and traditional aluminum electrolytic capacitors 

lies in their construction and the electrolyte materials used, which lead to significant differences in their performance:

Electrolyte material:

Traditional aluminum electrolytic capacitors typically use liquid electrolytes (such as borate solutions) or in some cases semi-solid paste electrolytes.

Aluminum polymer capacitors use conductive polymers as cathode materials, which are solid electrolytes commonly found in materials such as polypyrrole and polythiophene.

Equivalent series resistance (ESR):

Aluminum polymer capacitors typically have very low ESR due to the high conductivity of solid electrolytes, which makes them more outstanding in high-frequency applications, 

effectively filtering out ripple currents and reducing noise.

Traditional aluminum electrolytic capacitors have lower high-frequency performance compared to polymer capacitors due to the higher resistance and ESR of liquid electrolytes.

Temperature stability:

The capacitance of polymer capacitors changes little with temperature and has good temperature stability.

Capacitors with liquid electrolytes are greatly affected by temperature, and their capacitance and ESR will vary significantly with temperature.

Lifespan and reliability:

Aluminum polymer capacitors have no liquid leakage or drying problems, reducing the risk of bloating and bursting, longer lifespan, and higher reliability.

The electrolyte of traditional aluminum electrolytic capacitors may evaporate or dry over time, leading to a decrease in capacitance value and eventual failure.

Physical form:

Polymer capacitors can achieve smaller size and lighter weight, making them suitable for high-density packaging and miniaturization design.

Traditional aluminum electrolytic capacitors may require more space to accommodate and prevent leakage due to the liquid electrolyte.

Applicable fields:

Aluminum polymer capacitors are more suitable for high demand applications such as high-end motherboards, power converters, automotive electronics,
high-frequency communication equipment, etc. due to their superior performance.

Traditional aluminum electrolytic capacitors still hold a place in cost sensitive fields with less stringent requirements for volume and performance.

Aluminum polymer capacitors are superior to traditional aluminum electrolytic capacitors in terms of high-frequency performance, temperature stability,
lifespan, and reliability, but correspondingly, the cost may also be higher. The choice of which type of capacitor to use depends on the specific application requirements and budget.