Shear-aligned nanocelluloses enabling stable all-solid-state lithium batteries

Abstract

Composite polymer electrolytes (CPE) combining polymer matrix and functional fillers have gained significant attention due to their potential to overcome the limitations of single-component electrolytes. However, the disordered ion transport networks in conventional CPE limit their ionic conductivity and interfacial stability. Here, we propose a shear-induced alignment strategy to construct anisotropic architectures through precisely orienting lithiated cellulose nanocrystals (CNCs-Li) within poly(ethylene oxide) matrices. This ordered microstructure establishes planar Li⁺ transport highways with optimized coordination environments, achieving a room temperature (RT) ionic conductivity of 0.107 mS cm-1, representing a 1.7-fold enhancement over randomly structured counterparts. Facilitated ion migration enables homogeneous lithium deposition, demonstrating long-term cycling of 3200 h at 0.1 mA cm-2 under 60 °C in Li symmetric cells. The assembled LiFePO4/Li ASSLBs can maintain steady operation 500 cycles with an 85% capacity retention at 1 C and 60 °C and deliver RT capacities of 140 mAh g-1 at 0.5 C. This work provides a scalable strategy for designing high-performance CPE through structural anisotropy control.