Differential pulse voltammetry analytics for lithium-ion battery degradation

Highlights•An analytics approach based on pulse voltammetry is developed for lithium-ion batteries•A physics-based model is developed to capture key degradation mechanisms•Distinct degradation signatures manifest at different temperatures•Active material cracking plays a major role in the capacity fade at low temperaturesSummaryWith the growing need for lithium-ion batteries in high-power applications, an accurate estimation of battery state of health is critical for long cyclability. In this work, an analytics approach based on pulse voltammetry is presented for lithium-ion batteries. A physics-based modeling framework is developed to predict pulse voltammogram signatures for generic voltage pulses. In combination with a parameter estimation technique, this model presents an in situ diagnostic tool that captures key electrode-specific parameters with rapid accuracy. Using this approach, we quantify degradation descriptors such as the growth of the resistive layer, interfacial area evolution, and lithium-intercalation state. Pulse voltammetry signatures, obtained periodically during fast-charge cycling experiments, show distinct trends at low temperature and room temperature. Active particle cracking plays a major role in the low-temperature capacity fade of lithium-ion cells, while a combination of cracking and impedance rise is the major cause of degradation at room temperature.