Multiforce synergistic assembly-engineered chitosan-sodium carboxymethyl cellulose/LiFePO₄ composite thick electrodes...

Thick electrodes with high active material loading are considered ideal for Li-ion batteries, yet they suffer from intrinsic challenges of sluggish ion transport kinetics and poor mechanical stability. Although carbon-based scaffolds can enhance electron conductivity in conventional thick electrodes, their practical applications are hindered by complex fabrication processes, inefficient Li⁺ transport and high costs. This study constructed a three-dimensional conductive fibrous network through the synergistic integration of chitosan and sodium carboxymethyl cellulose, enabling the fabrication of high-loading self-supporting LiFePO₄ flexible paper electrodes. The fully aqueous processing eliminates conventional PVDF binders and metal current collectors, and the vacuum filtration-driven ordered deposition of active materials achieves precise control over interconnected porous structures and chemical compatibility. The unique gradient-layered porous architecture and continuous electron pathways significantly optimize ion/electron transport kinetics. The flexible paper electrode with a 20 mg cm^-2 LiFePO₄ mass loading delivers a high specific capacity of 165 mAh g^-1 at 0.1C, achieving a remarkable volumetric energy density of 578 Wh/L at a high LiFePO₄ mass loading of 40 mg cm^-2. This research enables the advancement an eco-friendly approach for developing high-energy-density and low-environmental-impact energy storage technologies.