The SiCWell project investigated how the use of silicon carbide (SiC) power converters influences the lifetime of traction batteries in electric vehicles. SiC devices enable higher switching frequencies and steeper switching edges, which increase the power density and efficiency of the inverter but also raise the amplitude and frequency of the DC‑bus ripple that the battery must tolerate. Laboratory life‑time tests on lithium‑ion cells were carried out with systematically varied switching frequencies, amplitudes and other parameters. The measurements demonstrated that overlapped ripple currents accelerate cell degradation, and an aging model was derived that quantitatively links the inverter design to the battery’s capacity fade. A simulation model based on this aging law was then developed, allowing designers to predict the impact of different inverter topologies and high‑voltage (HV) bus configurations on battery health. Parallel to the synthetic tests, real ripple currents were measured on a SiC inverter prototype, and the resulting data were incorporated into the simulation. The battery cells tested under a realistic driving profile proved highly durable; however, the planned cycle end could not be reached within the original project duration, prompting a nine‑month extension to May 2022 and a subsequent extension to November 2022. Open questions that remain include the quantitative effect of higher switching frequencies on capacitive currents, the influence of increased voltage gradients on electromagnetic interference (EMI), and the additional filtering measures required to mitigate these effects. The project’s findings were disseminated in several peer‑reviewed publications, including the SiCWell dataset, a study on the impact of fast‑switching SiC semiconductors on vehicle battery lifetime, and a paper on the influence of overlaid ripple current on battery aging.

SiCWell was a collaborative effort led by Mercedes‑Benz AG (MBAG) and supported by the Technical University of Berlin (TU Berlin) and other academic partners. MBAG was responsible for defining battery requirements, selecting test vehicles, and coordinating the overall project schedule. TU Berlin performed the numerical simulations of inverter currents, developed the aging model, and carried out the measurement campaigns on the SiC inverter. Other partners contributed data, expertise in battery chemistry, and support for the long‑term cycling tests. The project ran from 1 September 2018 to 30 November 2022, with two extensions approved by the funding agency. The grant was awarded by VDI/VDE Innovation + Technik GmbH under reference 16EMO0261K. During the project, 23 person‑months of effort were logged instead of the planned 29, largely due to early completion of the battery requirement phase and synergies that allowed simultaneous measurement campaigns. Material costs were reduced because battery cells were sourced from an existing production line and inverter components were provided from an internal project, while travel expenses fell below the budget because many meetings were held online amid COVID‑19 restrictions. The final report, submitted on 20 February 2023, confirms that the SiCWell project achieved its core objective of quantifying the impact of SiC inverter ripple on battery degradation and providing a validated simulation tool for future vehicle design.