High‐Entropy Prussian Blue Analogues Enable Synergistic Electronic Coupling and Charge Compensation for Efficient Li–CO ₂ Batteries

Abstract Lithium–carbon dioxide (Li–CO ₂ ) batteries possess an ultrahigh theoretical energy density and significant carbon capture capabilities but face challenges such as poor reversibility and limited cycling stability. To address these issues, a series of Prussian blue analogues with different entropy values and catalytic activities are fabricated and used as cathode catalysts for Li–CO ₂ batteries. Among low‐entropy, medium‐entropy, and high‐entropy Prussian blue analogues (PBAs), the quinary high‐entropy PBAs (HE‐PBAs) show superior redox kinetics with a higher discharge capacity, a lower charge potential, and better cycling stability. By incorporating five non‐noble metal elements (Fe ³⁺ , Mn ²⁺ , Ni ²⁺ , Co ²⁺ , and Cu ²⁺ ), HE‐PBAs within the porous Prussian blue framework combine a high‐entropy engineering strategy, electronic coupling effects, and a charge compensation network, enabling multi‐metal synergistic effects and optimizing the electronic structure of the catalysts. As the entropy of the PBAs increases from low to medium to high values, an electron rearrangement phenomenon occurs between various metal centers, altering electron density on Cu and Co, improving the decomposition and formation of lithium carbonate, reducing reaction barriers, and enhancing catalytic efficiency. This work sheds light on the entropy engineering of the catalysts for boosting the performance of Li–CO ₂ batteries.