A Metric for Benchmarking an Extreme Fast-Charging of Li-Ion Battery Electrode Materials

Abstract

In the search for a universal metric that would allow standard comparisons between the performance of different electrode materials, to evaluate extreme fast-charging capabilities, we suggest the definition of a universal metric, benchmarking battery electrode materials for extreme (BMX) fast charging (FC), as the maximum State-of-Charge (SoCmax) retained when a material is charged for 15 minutes under galvanostatic conditions. Our proposal for BMX-FC is based on a generic model that considers the influence of finite-diffusion, charge transfer kinetics, particle size, and  the overall charging rate (defined as a “C-rate”). In addition, a hierarchy of materials is established according to their lower or higher universal BMX-FC metric values, as well as predictions of modification in some parameters, required to enable extremely fast charging. The predictions are validated with experimental data from the literature.

Keywords: Fast-charging, Lithium-ion battery, benchmarking, Electrode materials, intercalation