Surface Superlattice-Induced Spatial Confinement Enables High Voltage and Long Cycle Life in Li-CO₂ Batteries

The development of high-performance lithium-carbon dioxide (Li-CO₂) batteries is crucial for advancing carbon-neutral energy storage systems. However, this system still faces the challenge of balancing high discharge voltage with long-term stability. To address this issue, we have successfully designed and synthesized a novel nanocrystalline PtIrFeCoCuZn (PIFCCZ) high-entropy intermetallic cathode catalyst with an L1₂-type atomic ordered structure. The surface superlattice of PIFCCZ induces a molecular-level spatial confinement effect, which effectively disrupts the conventional crystallization pathway of discharge products, enabling the separated nucleation and growth of finely crystalline Li₂CO₃ and amorphous Li₂C₂O₄. The precisely controlled interfacial coupling between discharge products and catalyst surface significantly enhances the reversible decomposition of discharge products and reduces the CO₂ evolution overpotential to 0.24 V. The Li-CO₂ battery incorporating this catalyst achieved a high discharge voltage of 3.08 V, an energy efficiency of 93.7%, and stable operation for over 1000 h at a current density of 20 μA·cm^-2. This study provides a breakthrough strategy for resolving the inherent trade-offs among output voltage, energy efficiency, and cycling stability in Li-CO₂ batteries.