Surface Potential Well-Gated Piezocarrier Escape for Reversible Oxygen Redox in Lithium-Oxygen Chemistry.

Piezocatalysis offers a promising way to harness intrinsic mechanical energy for accelerating sluggish oxygen redox reactions in lithium-oxygen batteries. However, its efficiency depends not just on piezoelectric polarization strength, but critically on whether stress-induced charge carriers can escape surface potential traps at terminations and reach interfacial reactive states. Here, we introduce a surface-trap-gated carrier escape mechanism via a chemically bridged Co3O4@Ti3C2Tx MXene (Co3O4@TMX) interface. Co─O─Ti coupling induces local secondary symmetry breaking in Ti3C2Tx-MXene and reshapes the electrostatic potential at termination sites, converting deep-trapped states into low-barrier interfacial escape pathways. During battery operation, periodic Li2O2 evolution generates intrinsic mechanical stress, continuously activating the piezoelectric response. The resulting electrons overcome termination confinement, inject into the active domains of Co3O4, and sustain electron flux for O2 activation and reduction intermediate generation. Concurrently, interfacial holes create transient electron-deficient regions that extract electrons from Li2O2, promoting its oxidative decomposition. This shifts the core piezocatalytic criterion from "Can sufficient piezoelectric potential be generated?" to "Can piezoelectric carriers transition from trapped to interfacial reactive states?", enabling synergistic coupling of mechanical stress, interfacial potential, and oxygen electrochemistry.