Unveiling the (de)lithiation heterogeneity of SiO/Graphite composite anodes in a 150 Ah high-energy-density Li-ion prismatic cell

Silicon monoxide (SiO)-graphite (Gr) composite anodes are considered as an ideal choice for next-generation lithium-ion batteries. However, the (de)lithiation heterogeneity within composite electrodes and the effect of SiO incorporation on batteries are not studied clearly. To get a deep insight, an extended pseudo-2-dimension (P2D) model based on a 150 Ah high-energy-density (HED) Li-ion prismatic cell with SiO/Gr blended anode and Ni-rich ternary cathode couple is established. The effect of SiO content, the interaction between SiO and graphite particles, and the inhomogeneity through the whole electrode are all investigated at a multiscale of material-electrode-battery. We find that SiO particles are preferential lithiation and lagging de-lithiation in the SiO/Gr blended anodes at the SOC range of 0 similar to 0.91. Unlike the SiO particles, the big SOC inconsistency in graphite particles across the electrode thickness direction cannot be eliminated by Li+ redistribution during the relaxation process, when particles with different SOCs (such as 0.65-0.95) have the same equilibrium potential. Therefore, the potential plateaus of graphite are the main obstacle to its high-rate charging performance. Incorporating SiO particles is beneficial to the high-rate and low-temperature charging performance to a certain extent, owing to its relatively higher equilibrium potential and preferential lithiation behaviour.