Revisiting the Kinetics Enhancement Strategies of Si Anode through Deconstructing Particle-Interface-Electrode Integration

Abstract

The successive introduction of silicon (Si) graphite composite anodes into the global market highlights the tremendous commercial potential of Si anodes. Good kinetic performance related to fast charging capability is the central topic of next-generation Si anodes. However, there is a lack of critical reviews to explore the fundamental limiting factors affecting the kinetics of Si and evaluate the effectiveness of the current strategies. In this review, we deconstruct the particle-interface-electrode integration to analyze key limiting factors of kinetics from a practical application perspective for the first time, involving long Li+ diffusion distance and poor conductivity for particles, high Li+ migration impedance at the interface, and insufficient or even interrupted Li+ diffusion paths inside the electrodes. Then, the kinetics enhancement strategies on progressively addressing the above issues are systematically investigated and the quantitative relationships between kinetics and these strategies are deeply discussed. Accordingly, the necessary challenges in quantification and balance for fast-charging Si anodes are identified as the remaining issues, and potential solutions are provided. This review can provide valuable guidance on fast-charging Si anodes and suggest promising directions in commercial-oriented Si anode studies.