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<p>The rapid advancement of new energy vehicle technologies has drawn significant attention to silicon-based anodes due to their exceptionally high theoretical capacity and environmental friendliness. However, the substantial volume expansion (approximately 300%) during lithiation often leads to structural fracture and pulverization, thereby deteriorating cycling stability. Recently, nano-Si–Cu composite anodes fabricated via laser micro-cladding and dealloying have demonstrated improved mechanical stability and excellent cyclic charge–discharge performance. Yet, the influence of composite anode parameters—such as initial porosity, initial Si–Cu volume ratio, and skeleton modulus including copper—on the overall modulus of the composite anode, as well as the corresponding fracture behavior in relation to modulus evolution, remains challenging to elucidate through experiments alone. In this work, a two-dimensional representative volume element and a composite anode–current collector model are developed for porous Si–Cu composite anodes. By integrating chemo-mechanical coupling theory with numerical simulations and mathematical modeling, we systematically investigate the contributions of various parameters to modulus evolution under the dual—and opposing—mechanisms of softening effect and mesostructural evolution, along with the fracture response of the composite anode to modulus changes. Results indicate that as the initial porosity and Si–Cu volume ratio increase, the effective modulus of the electrode decreases; however, beyond critical values (58% porosity and a volume ratio of 3.6), the fully lithiated modulus exhibits an increase. Similarly, when the skeleton modulus falls below a threshold of 110 GPa, an increase in the composite modulus is observed. Although a higher modulus suppresses bending curvature, it shifts the neutral plane toward the current collector, exacerbating surface crack propagation and leading to a notable rise in the stress intensity factor. This study elucidates the role of composite anode parameters in modulus evolution and the corresponding fracture behavior, providing a theoretical foundation for the structural optimization of high-capacity, long-life silicon-based composite anodes.</p>

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Regulation Mechanisms of Component Parameters on Modulus in Silicon-Based Composite Anodes and Their Contributions to Fracture Behavior

  • 期刊论文

  • 发表日期：

    2026年4月20日

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  • Zhonglin Zhang,
  • Han Li,
  • Tao Wang,
  • Longfei Li,
  • Yutao Shi,
  • Feng Zhang,
  • Jianqiu Zhou

摘要

The rapid advancement of new energy vehicle technologies has drawn significant attention to silicon-based anodes due to their exceptionally high theoretical capacity and environmental friendliness. However, the substantial volume expansion (approximately 300%) during lithiation often leads to structural fracture and pulverization, thereby deteriorating cycling stability. Recently, nano-Si–Cu composite anodes fabricated via laser micro-cladding and dealloying have demonstrated improved mechanical stability and excellent cyclic charge–discharge performance. Yet, the influence of composite anode parameters—such as initial porosity, initial Si–Cu volume ratio, and skeleton modulus including copper—on the overall modulus of the composite anode, as well as the corresponding fracture behavior in relation to modulus evolution, remains challenging to elucidate through experiments alone. In this work, a two-dimensional representative volume element and a composite anode–current collector model are developed for porous Si–Cu composite anodes. By integrating chemo-mechanical coupling theory with numerical simulations and mathematical modeling, we systematically investigate the contributions of various parameters to modulus evolution under the dual—and opposing—mechanisms of softening effect and mesostructural evolution, along with the fracture response of the composite anode to modulus changes. Results indicate that as the initial porosity and Si–Cu volume ratio increase, the effective modulus of the electrode decreases; however, beyond critical values (58% porosity and a volume ratio of 3.6), the fully lithiated modulus exhibits an increase. Similarly, when the skeleton modulus falls below a threshold of 110 GPa, an increase in the composite modulus is observed. Although a higher modulus suppresses bending curvature, it shifts the neutral plane toward the current collector, exacerbating surface crack propagation and leading to a notable rise in the stress intensity factor. This study elucidates the role of composite anode parameters in modulus evolution and the corresponding fracture behavior, providing a theoretical foundation for the structural optimization of high-capacity, long-life silicon-based composite anodes.