Our analysis has also led us to propose voltage pulses, a novel method of measuring battery degradation, using a "fitness" framework . One of the key advantages of the voltage pulse method is the explicit physical separability of degradation mechanisms from the fitness framework, shown in Eq. 8. This contrasts with implicit formulations in current pulses by simplifying numerical calculations. Voltage pulses additionally mitigate population dynamics effects for phase-separating materials, increasing diagnostics accuracy . In addition, voltage pulses are physically closely linked to rate capability. Rate capability holds high importance in battery operation relative to conventional long-term degradation metrics, such as lifetime .