Design of quasi-solid-state electrolyte with continuous Li+ pathways via bridging cellulose and α-Li2TiO3 for lithium batteries

Developing low-cost and renewable quasi-solid-state electrolytes (QSSEs) is critical for advancing energy storage technologies. Cellulose-based QSSEs have attracted considerable attention for their inherent renewability and cost advantages. However, discontinuous Li+ conduction pathways within cellulose frameworks severely limit their development as advanced electrolyte materials. Herein, an “ion-bridge” strategy is proposed, in which zeolitic imidazolate framework-67 (ZIF-67) serves as a bridge to connect α-Li2TiO3 and bacterial cellulose (BC), forming a BC/ZIF-67@Li2TiO3 hybrid electrolyte. This strategy effectively constructs interconnected long-range Li+ transport channels within the electrolyte, achieving a high ionic conductivity of 2.3 × 10-3 S cm-1 and a lithium-ion transference number of 0.81. Notably, α-Li2TiO3 serves as a highly favorable filler with excellent Li+ conductivity. Moreover, it provides an “active defense” mechanism against lithium dendrites through a tip-shielding effect, thereby reducing the risk of dendrite penetration. The Li|BC/ZIF-67@Li2TiO3|LiFePO4 (LFP) full cell demonstrates exceptional cycling stability, retaining 89% of its initial capacity after 900 cycles at 1 C. This work provides a robust strategy for developing QSSEs that balance electrochemical performance and sustainability.