CATL claims zero battery degradation after 5 years: While preventing the degradation of capacity over the first five years of use is a significant advancement in increasing the lifespan of batteries, the zero degradation of power is also important for energy storage power plants aiming to meet the requirements of new electric power systems.
The battery degradation in this use case was mainly driven by the cycling ageing (96%), caused by slow but deep cycles. Only 4% of the total capacity loss was caused by calendar ageing. Most battery degradation studies refer to modelled data without validating the models with real operational data, e.g. [10,12,17].
The impact of operating strategy and temperature in different grid applications Degradation of an existing battery energy storage system (7.2 MW/7.12 MWh) modelled. Large spatial temperature gradients lead to differences in battery pack degradation. Day-ahead and intraday market applications result in fast battery degradation.
Most battery degradation studies refer to modelled data without validating the models with real operational data, e.g. [10, 12, 17]. In this research, data from a BESS site in Herdecke (GER) operated by RWE Generation is used to analyse the degradation behaviour of a lithium-ion storage system with a capacity of 7.12 MWh.
Estimated state of health (SoH) for different temperatures of the examined BESS in Herdecke for operation in the FCR market (For interpretation of the references to color in this figure, the reader is referred to the web version of this article.). On average the battery packs degrade roughly 1.55% per year.
While preventing the degradation of capacity over the first five years of use is a significant advancement in increasing the lifespan of batteries, CATL says the zero degradation of power is also important for energy storage power plants that intend to meet the requirements of new electric power systems.