Lithium-selective “OR-gate” enables fast-kinetics and ultra-stable Li-rich cathodes for polymer-based solid-state batteries

Abstract

The utilization of high-capacity lithium-rich layered oxide (LRLO) in lithium-ion batteries is hampered by its severe interface reactions and poor interface dynamics. Herein, an OG gate (OG) is constructed on the surface of LRLO to alleviate its interface issues. The OR gate, consisted of layered hydrotalcite with a negatively charged interlayer and high dielectric constant, enable selectively enhance the Li+ transportation. Benefited from the Li+ selectivity, OG-coated LRLO shows outstanding cycle performance, with a capacity retention rate of 91.9 % after 100 cycles at 1C (from 197.9 mAh g−1 to 182.0 mAh g−1). Moreover, the OG demonstrates a good voltage-division effect and interface stability, making it suitable for solid polymer electrolyte (SPE) systems. Interestingly, when combined with an SPE, the OG-coated LRLO delivers a capacity retention rate of 80.0 % after 150 cycles at 0.2 C and an ultrahigh electrode-electrolyte energy density of 437.2 Wh Kg−1. This approach presents a simple and effective mechanism for adapting LRLO to solid-state battery, enhancing the practical utilization of high-energy-density solid-state batteries.