Bifunctional Electrocatalysts in Rechargeable Lithium‐Gas Batteries: Material Evolution and Mechanistic Insights from Metal‐Free Carbons to Carbon‐Supported Single‐Atom Sites

batteries (LNBs) systems, offer superior energy density and promising long-term stability. However, their widespread implementation is hindered by slow gas-conversion kinetics, causing high overpotentials, low-rate performance, and limited electrochemical reversibility, which severely affects cycling stability. Addressing these challenges requires designing bifunctional electrocatalysts that enhance both discharge and charge reactions for efficient gas conversion. Carbon-based metal-free electrocatalysts (C-MFECs) and carbon-supported single-atom catalysts (CS-SACs) are highly promising alternatives, distinguished by their outstanding catalytic activity for efficient reactant activation and product decomposition. This review offers an in-depth analysis of LGBs, discussing the key challenges that hinder gas-conversion reversibility and emphasizing the origin of bifunctional catalytic activity in C-MFECs and CS-SACs. We further explore recent advances in LGB applications, highlighting strategies to improve catalytic efficiency and electrochemical reversibility. Finally, we outline future directions for developing bifunctional C-MFECs and CS-SACs, focusing on material innovation, mechanistic insights, and practical implementation to drive the development of sustainable next-generation LGBs.