Crack pinning enables stable cycling of micro-sized silicon anodes for wide-temperature lithium-ion batteries

Abstract

Silicon anodes promise revolutionary lithium-ion battery energy density, yet commercial viability remains constrained by catastrophic volume expansion and interfacial degradation under demanding thermal conditions. Here, we demonstrate engineered crack pinning mechanisms within a gradient-structured hybrid solid–electrolyte interphase (H-SEI) that enables unprecedented cycling stability of micro-sized silicon anodes across extreme temperatures. The dual-layer H-SEI architecture features nanocrystalline inorganic domains providing grain-boundary strengthening, while polymer-integrated outer layers incorporate distributed nanocrystals as crack arresters, preventing fracture propagation through synergistic stress redistribution. This crack pinning strategy maintains structural integrity under ∼200% volumetric expansion, preserving continuous wide-temperature lithium-ion transport. Paired with NCM811 cathodes, 1-Ah pouch cells exhibit long cycle life, retaining >80% capacity from −20 °C to 70 °C over extended cycling, substantially exceeding existing silicon technologies. These findings establish crack pinning as a transformative approach for thermally-robust silicon batteries, enabling next-generation energy storage across diverse environmental conditions.