ENPOLITE: Comparing lithium-ion cells across energy, power, lifetime, and temperature
Abstract & Method
Lithium-Ion battery lifetimes from cyclic and calendar aging tests of more than 1000 cells were compared employing novel plots termed ENPOLITE (energy-power-lifetime-temperature). Battery aging data from in-house measurements and published data were combined into a uniform database; the total dataset size exceeds 1000 GB. At a glance, ENPOLITE plots inform about the nominal capacity, cell format, cell chemistry, average aging test duration, measurement temperature, specific power employed for testing, energy density, and the achieved lifetime for every cell. A battery lifetime coefficient was derived, allowing the comparison of lithium-ion batteries with different weights or volumes, capacities, and cell chemistries. The combination of multiple parameters in ENPOLITE facilitated a thorough comparison of various battery degradation. In addition to the cell-specific parameters during cycling, the specific stored energy and the storage temperature were depicted in a calendar ENPOLITE-Plot.
Part of the work was done within the research project “E2Fuels” (03EIV011F) funded by the German Federal Ministry for Economic Affairs and Energy (BMWi). This work was supported also by the US Department of Energy Office of Electricity, Energy Storage Program.