A microstructure design-assisted prelithiation method for SiO/Graphite composite anode enabling controllable prelithiation efficiency and homogeneity

Abstract

Prelithiation emerges as a promising strategy to compensate the irreversible initial capacity loss of the SiO/Graphite (SiO/Gr) composite anode. However, many scalable prelithiation methods encounter challenges of low efficiency and inhomogeneity, primarily stemming from a limited understanding of the spatial and temporal variations in prelithiation kinetics within large-scale electrodes. Utilizing an electrochemical prelithiation model, we integrated optimal electrode structure design with an electrochemically controllable method to concurrently enhance prelithiation efficiency and homogeneity. We demonstrated that prelithiation efficiency can be controlled by specifying the prelithiation current, while the design of the channel arrangement in the perforated electrode can enhance prelithiation homogeneity. Furthermore, we elucidated the interaction mechanism among channels under varying prelithiation currents and explored the impacts of channel size, channel spacing, and channel arrangement on prelithiation homogeneity under high prelithiation efficiency. With the insight gained from our simulation, the SiO/Gr composite anode featuring a channel diameter of 500 μm and a square channel arrangement with a spacing of 8.7 mm was designed. This design achieved a high prelithiation efficiency within 10 h, and maintained the prelithiation nonuniformity parameter below 0.1, accelerating the practical implementation of high-energy-density SiO/Gr composite anodes.