Interfacial Phase Transformation Enabled Crystallographic Selectivity for Efficient Li₂CO₃ Decomposition Toward...

The formation and decomposition of Li₂CO₃ dictate the reversibility of Li-CO₂ batteries. However, as an electronically insulating and stable solid, the random deposition of Li₂CO₃ 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 Li₂CO₃ 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 MoS₂ is selected as a model catalyst due to its two-dimensional structure and phase-dependent electronic properties. By constructing a MoS₂@CuS heterointerface, a controllable 2H to 1T phase transition is induced, reconstructing the interfacial electronic structure and directing the oriented growth of Li₂CO₃. 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-MoS₂ exhibits stronger interfacial interactions with Li₂CO₃, 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-CO₂ batteries.