Chain‐Networked Micro‐Silicon Electrodes Inducing Internal Isostatic Compressive Stress for High‐Energy and High‐Power Solid‐State Batteries

Abstract

Micron‐sized silicon (µ‐Si) offers a scalable pathway to high‐capacity anodes, and its application in solid‐electrolyte‐free systems has garnered attention as a strategy to maximize energy density. However, achieving both high energy and power densities in such configurations remains challenging due to the lack of internal ionic conduction pathways and stress‐accommodation mechanisms. Here, we report a Chain‐based Networking (CN)‐Si electrode architecture that overcomes these limitations and maximizes energy and power densities without incorporating solid electrolytes within the electrode. In this design, µ‐Si particles are tightly wrapped and interconnected by single‐walled carbon nanotubes (CNTs), forming a mechanically robust conductive network. The CNT wrapping imposes compressive stress during lithiation, distributing internal strain and preventing crack and void formation, mimicking the stress‐dissipation principle of Prince Rupert's drop. As a result, the CN‐Si electrode delivers superior electrochemical performance, with 78% capacity retention at 3C, significantly outperforming conventional Si electrodes using polymer or carbon black binders. In full‐cell configurations with LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NCM811) cathodes, the CN‐Si electrode retains 78.8% capacity after 3000 cycles at a high C‐rate (5C). These findings demonstrate that stress‐engineered micro‐Si architectures can simultaneously overcome kinetic limitations and maximize both energy and power densities in solid‐state battery systems, advancing practical high‐performance All‐Solid‐State Batteries (ASSBs).