Digital System EV Battery-Type Considerations: Cycles

Digital System EV battery-type cycles vary according to the underlying battery type.  A battery cycle consists of going from a minimal charge state to a full charge state and back to minimal charge state after re-use of the stored energy.

EV Lithium-Ion batteries initially supported ~2000 battery cycles, while newer designs reach ~5000 battery cycles. As the number of battery cycles increase, the storage capacity decreases for Li-Ion batteries over time.  Mechanical batteries, typically a rotating-mass used as storage can range ~100,000 to ~10,000,000 battery cycles.  A mechanical battery is sometimes referred to as a flywheel battery.  A flywheel battery stores energy input as an electrical energy into a rotating mass energy; while reusing the flywheel energy when needed.  Formula E cars store vehicle brake energy into a flywheel battery entering a corner, and reuse the stored energy leaving the same corner as added current to the electrical drive-motor, for example.  

Flywheel Battery:
https://en.wikipedia.org/wiki/Flywheel_energy_storage

Advanced Flywheel Energy Systems (FES) have rotors made of high strength carbon fiber composites, suspended by magnetic bearings, and spinning at speeds from 20,000 to over 50,000 RPM in a vacuum enclosure. Such flywheels can come up to speed in a matter of minutes – reaching their energy capacity more quickly than some other forms of storage.

Super Capacitor Battery:  

https://en.wikipedia.org/wiki/Supercapacitor

It have inherent advantages in terms of battery cycles, and performance.  The latter two EV battery types have higher initial costs; yet provide other advantages, such that an EV battery design might consider a hybrid battery design for reduced weight, and improved efficiency:

(1) Flywheel + Li-Ion

(2) SuperCap + Li_Ion

Flywheel and SuperCap batteries become a digital cache equivalent in an EV battery system?