Fractional-order dynamics can form physically interpretable equivalent-circuit models (ECMs) of the diffusion overpotential in lithium-ion batteries (LIBs) but have complex formulations in the time domain. Meanwhile, resistor–capacitor circuits have simple implementations but little physical meaning. Thus, we propose a discrete-time state-space diffusion model, named “receding-horizon diffusion” (RHD). It combines physical interpretability with computational simplicity. Analogous to the Warburg element in impedance spectroscopy, the RHD constant is explicitly linked with the lithium-ion diffusion coefficient. Fivefold validation of the RHD model using simulated and experimental from lithium NiMnCo and NiCoAl cells up to 3 C-rate, temperatures from 0 °C to 25 °C, and wide ranges of states of health and charge. The model has less than 1% modeling error. Ohmic, charge-transfer, and diffusion overpotentials are tracked in real time. The RHD model could be integrated into battery management systems (BMSs) in electric vehicles (EVs) and used in standard state estimation techniques.
Interpretable Real-Time Modeling of the Diffusion Overpotential in Lithium Batteries
IEEE Transactions on Transportation Electrification ; 9 , 3 ; 4605-4612
2023-09-01
4325941 byte
Article (Journal)
Electronic Resource
English
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