Interfacial Phase Transformation Enabled Crystallographic Selectivity for Efficient Li 2 CO 3 Decomposition Toward Long‐Cycling Li‐CO 2 Batteries

ABSTRACT The formation and decomposition of Li 2 CO 3 dictate the reversibility of Li‐CO 2 batteries. However, as an electronically insulating and stable solid, the random deposition of Li 2 CO 3 causes interfacial blockage and high decomposition barriers, severely limiting performance. Herein, we propose a facet‐preferred growth strategy to regulate the structure of discharge products. Different Li 2 CO 3 facets possess distinct surface energies, atomic arrangements, and interfacial reactivities, making selective growth an effective route to optimize electrochemical behavior. This process is governed by catalyst‐product interfacial interactions, requiring both structural adaptability and tunable electronic coupling. Layered MoS 2 is selected as a model catalyst due to its two‐dimensional structure and phase‐dependent electronic properties. By constructing a MoS 2 @CuS heterointerface, a controllable 2H to 1T phase transition is induced, reconstructing the interfacial electronic structure and directing the oriented growth of Li 2 CO 3 . Consequently, the battery exhibits a low overpotential (0.46 V), high energy efficiency (∼92.4%), and excellent cycling stability (>1800 h). Theoretical calculations reveal that 1T‐MoS 2 exhibits stronger interfacial interactions with Li 2 CO 3 , preferentially stabilizing the (‐110) facet, lowering decomposition barriers, and promoting oriented nucleation and epitaxial growth. This work establishess a direct link among catalyst structure, interfacial interaction, and product crystallographic orientation, providing a new strategy for high‐performance Li‐CO 2 batteries.