Rechargeable Li–CO2 batteries have attracted worldwide attention due to the capability of CO2 capture and superhigh energy density. However, they still suffer from poor cycling performance and huge overpotential. Thus, it is essential to explore highly efficient catalysts to improve the electrochemical performance of Li–CO2 batteries. Here, phytic acid (PA)‐cross‐linked ruthenium complexes and melamine are used as precursors to design and synthesize RuP2 nanoparticles highly dispersed on N, P dual‐doped carbon films (RuP2‐NPCFs), and the obtained RuP2‐NPCF is further applied as the catalytic cathode for Li–CO2 batteries. RuP2 nanoparticles that are uniformly deposited on the surface of NPCF show enhanced catalytic activity to decompose Li2CO3 at low charge overpotential. In addition, the NPCF its with porous structure in RuP2‐NPCF provides superior electrical conductivity, high electrochemical stability, and enough ion/electron and space for the reversible reaction in Li–CO2 batteries. Hence, the RuP2‐NPCF cathode delivers a superior reversible discharge capacity of 11951 mAh g−1, and achieves excellent cyclability for more than 200 cycles with low overpotentials (<1.3 V) at the fixed capacity of 1000 mAh g−1. This work paves a new way to design more effective catalysts for Li–CO2 batteries.

Lithium-carbon dioxide (Li-CO 2 ) batteries have received wide attention due to their high theoretical energy density and CO 2 capture capability. However, this system still faces poor cycling performance and huge overpotential, which stems from the leakage/volatilization of liquid electrolyte and instability of the cathode. A gel polymer electrolyte (GPE)-based Li-CO 2 battery by using a novel pencil-trace cathode and 0.0025 mol L −1 (M) binuclear cobalt phthalocyanine (Bi-CoPc)-containing GPE (Bi-CoPc-GPE) is developed here. The cathode, which is prepared by pencil drawing on carbon paper, is stable because of its typical limited-layered graphitic structure without any binder. In addition, Bi-CoPc-GPE, which consists of polymer matrix filled with liquid electrolyte, exhibits excellent ion conductivity (0.86 mS cm −1 ), effective protection for Li anode, and superior leakproof property. Moreover, Bi-CoPc acts as a redox mediator to promote the decomposition of discharge products at low charge potential. Interestingly, different from polymer-shaped discharge products formed in liquid electrolytebased Li-CO 2 batteries, the morphology of products in Li-CO 2 batteries using Bi-CoPc-GPE is film-like. Hence, this polymer-based Li-CO 2 battery shows superhigh discharge capacity, low overpotential, and even steadily runs for 120 cycles. This study may pave a new way to develop high-performance Li-CO 2 batteries.

A lithiophilic Co/Co4N-N-doped carbon electrode displays a high coulombic efficiency (98.5%) and dendrite-free morphology for long-life Li–air batteries.