Advanced yolk-shell microstructure for high-efficiency electromagnetic wave absorption: A critical review on composition-structure synergy

Abstract

The rapid proliferation of 5G/6G communication technologies and high-frequency electronic devices has led to escalating electromagnetic (EM) pollution and EM wave absorbing materials (EWAMs) are crucial for mitigating EM pollution. Beyond conventional composition optimization, rational microstructure engineering (such as porous, hollow, and aerogel architectures) has emerged as an alternative and effective route to enhance the performance of EWAMs. Among these diverse architectures, the yolk-shell structure has garnered significant attention by integrating the advantages of both hollow and core-shell configurations. Its unique core-void-shell geometry not only facilitates impedance matching through the regulation of effective permittivity but also provides abundant heterogeneous interfaces for intensified dielectric and magnetic losses. This review provides a comprehensive overview of recent advancements in yolk-shell EWAMs, focusing on the synergy between chemical composition and microstructural design. We first summarize typical preparative strategies, including nanocasting, phase engineering, and heterointerface anti-contraction techniques. And then we categorize and discuss various yolk-shell systems, which range from conventional configurations with single-component cores and single-component shells to novel architectures featuring multi-component cores and shells. Ultimately, we present the prospects and unresolved challenges of yolk-shell materials, and anticipate that this review can provide a meaningful reference for advancing the structural design of EWAMs in subsequent research.