A long cycle lifespan and high energy efficiency Li–CO₂ battery enabled by dual-active site AuRu catalysts on TiO₂

Lithium–carbon dioxide (Li–CO₂) batteries have attracted considerable attention due to their high theoretical energy densities and potential for capturing and converting CO₂ toward net-zero carbon dioxide emissions. However, the reversible cycling capability of Li–CO₂ batteries is greatly limited by the sluggish kinetics of the CO₂ evolution reaction (CO₂ER), which leads to excessive charge voltages exceeding 4.0 V, thus significantly hindering the practical advancement of the battery technology. Herein, we report dual-active-site AuRu catalysts supported on TiO₂ nanorod arrays, grown on carbon nanofiber, where TiO₂ layers effectively prevent carbon corrosion and the electronic synergy of the dual active site design comprising Au and Ru can lower the reaction energy barriers of the CO₂ reduction reaction (CO₂RR) and CO₂ER. Calculation results reveal that this synergy gives rise to complementary catalytic roles: Au facilitates CO₂ activation, whereas Ru promotes Li₂CO₃ breakdown, collectively enhancing the overall reaction kinetics. Consequently, Li–CO₂ batteries employing AuRu/TiO₂ cathode deliver an ultralong cycle life exceeding 1100 cycles (~ 2200 h), low charge voltages (2.9–3.1 V), high energy efficiency (~ 77.9%), and excellent stability at elevated temperatures. This work establishes a generalizable catalyst-support strategy for long lifespan metal–CO₂ batteries, offering a promising route toward high-performance carbon neutral energy storage devices.