A 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 oxides (LRLOs) in lithium-ion batteries is hampered by their severe interface reactions and poor interface dynamics. Herein, an OR gate (OG) is constructed on the surface of a LRLO to alleviate its interface issues. The OR gate, consisting of layered hydrotalcite with a negatively charged interlayer and high dielectric constant, selectively enhances the Li⁺ transportation. Benefiting from the Li⁺ selectivity, the OG-coated LRLO shows outstanding cycle performance, with a capacity retention rate of 91.9% after 100 cycles at 1C (from 197.9 mA h g⁻¹ to 182.0 mA h 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 0.2C and an ultrahigh electrode–electrolyte energy density of 437.2 W h kg⁻¹. This approach presents a simple and effective mechanism for adapting LRLOs to solid-state batteries, enhancing the practical utilization of high-energy-density solid-state batteries.