Kinetic origin and mitigation of sudden capacity fade in silicon-based lithium-ion batteries

Abstract

Silicon (Si)-based full cells maintain stable cycling at elevated temperatures yet exhibit a sudden capacity fade at room temperature. This temperature-dependent behavior is specific to Si-based full cells and cannot be explained by conventional graphite-based degradation models. This study identifies the origin of the fade mechanism as a Si-intrinsic, kinetics-driven degradation process and proposes a corresponding mitigation strategy. Electrochemical and post-mortem analyses show that intrinsically sluggish Si kinetics at 25 degrees C induce a large overpotential that drives lithium plating and accelerates surface degradation. Guided by this understanding, a formation strategy is introduced to suppress lithium plating onset, which is shown to prevent sudden capacity fade and improve capacity retention from 38% to 85% in NCM/Si cells and from 55% to 93% in NCM/Si-Gr cells. By elucidating the kinetic origin of the sudden capacity fade and establishing formation engineering as an effective and scalable control strategy, this work addresses key challenges in the practical implementation of high-energy Si-based lithium-ion batteries. (c) 2026 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.