Li+ Shuttle bus enables safe fast ion transport in solid polymer electrolytes
In the authors' words
Solid polymer electrolytes are important for lithium metal batteries, but their limited Li+ transference efficiency hinders large-scale deployment. Here we report a Li⁺ shuttle bus strategy that immobilizes anions at one-dimensional charged interface, promotes lithium salt dissociation, and guides Li⁺ enrichment. The effect of Coulombic repulsion among densely coordinated Li⁺ species weakens solvation structure for Li+, achieving fast, collective and one-dimensional ion shuttling at the microscopic scale. Consequently, the designed solid polymer electrolyte exhibits a high ionic conductivity of 0.92 × 10−3 S cm−1 at 28 °C. Li | |LiFePO4 cells operate nearly 5000 cycles at 5 C and maintain 77% capacity after 900 cycles at −40 °C. Li | |LiNi0.8Co0.1Mn0.1O2 pouch cell further realizes high specific energy (508 Wh kg−1, 200 cycles, 95.2% retention). This work establishes a Li⁺ shuttle-bus strategy for constructing solid polymer electrolytes with fast-charging capability and wide-temperature adaptability, offering findings into the design of solid-state lithium metal batteries. Solid polymer electrolytes suffer from sluggish Li⁺ transport. Here, authors develop a shuttle-bus strategy that weakens Li⁺ solvation through Coulombic repulsion, enabling collective ion transport and Li | |NCM811 pouch cells with 508 Wh kg⁻¹ and 95.2% capacity retention after 200 cycles.
Appeared: Saturday, September 26. Nature Communications. Peer-reviewed journal.