Breaking insulating barriers in solid-phase conversion reactions with dual-atom catalysts for high-energy lithium batteries

Abstract

Batteries based on redox chemistry, such as lithium–sulfur and lithium–oxygen, can store more energy than conventional lithium-ion batteries. However, their chemical reactions are limited by sluggish and incomplete conversion reactions, especially those involving insulating solid intermediates (for example, Li2S2 and Li2O2), in which electrocatalysts play a decisive role. Here, through a large-scale theoretical analysis, we propose an electronic property criterion that emphasizes the efficient conduction of ions and electrons as essential for high catalytic activity. Guided by this insight, we have designed a CoCo dual-atom catalyst that accelerates the conversion of solid insulating Li2S2 and Li2O2 intermediates by effective orbital coupling, making these intermediates conductive and catalytically active. This strategy enables the fabrication of high-energy lithium–sulfur pouch cells at the ampere hour scale, achieving a specific energy of 459 Wh kg−1. Our results extend the fundamental understanding of rate-determining solid-phase reactions in redox chemistry and provide principles for the design of electrocatalysts for use in energy storage systems. Conversion-type batteries involving solid–solid transformations can store more energy than intercalation materials; however, their rates and cyclability have been limited by kinetics and incomplete conversion. This study introduces homonuclear dual-atom catalysts that increase the conductivity of insulating solid intermediates to enhance lithium–sulfur (and lithium–air) battery performance.