Boosting the Efficiency and Stability of Li-CO₂ Batteries via a Ruthenium-Based Olefin-Metathesis Catalyst

The practical application of Li-CO₂ batteries is significantly hindered by high charge potential and short lifespan, mainly due to sluggish reaction kinetics and inadequate reaction reversibility. Homogeneous catalysts added to the electrolyte provide a promising strategy to address these issues. In this work, the third-generation Grubbs catalyst (G-III), which is efficient for olefin metathesis reactions, has been adopted as a homogeneous catalyst for Li-CO₂ batteries. Batteries with G-III exhibited a low overpotential of 0.86 V and a lifespan of 1300 h at a current density of 300 mA g^-1. Even at a high current density of 2000 mA g^-1, the batteries remained stable for over 300 cycles, with an initial overpotential of 1.11 V. A two-step discharge/charge reaction involving Li₂C₂O₄ as an intermediate was well illustrated, attributed to both low overpotentials and high specific capacity. These findings provide insights into catalyst selection and mechanism analysis for Li-CO₂ batteries, offering practical strategies for Li-CO₂ battery performance enhancement and practical applications.