Homogeneous In-Plane Lattice Strain Enabling d-Band Center Modulation and Efficient d–π Interaction for an Ag2Mo2O7 Cathode Catalyst With Ultralong Cycle Life in Li-O2 Batteries

Although lithium–oxygen batteries (LOBs) hold great promise as future energy storage systems, they are impeded by insulated discharge product Li 2 O 2 and sluggish oxygen reduction reaction/oxygen evolution revolution (ORR/OER) kinetics. The application of a highly efficient cathode catalyst determines the LOBs performance. The d-band modulation and catalytic kinetics promotion are important concept guidelines for the performance enhancement of cathode catalysts. In this work, the homogeneous in-plane distortion-derived synergistic catalytic capability of an Ag 2 Mo 2 O 7 catalyst with modulated d-band centers and promoted ORR/OER kinetics is demontrated. The uniform elongation of Ag─O bonds and compression of Mo─O bonds in (020) plane leads to d-band splitting and d-band center optimization and delivers improved adsorption behavior for high ORR/OER capability. Furthermore, the spatial and energy overlap of Ag d xz and O 2 anti-bonding π * orbitals facilitate electron injection during ORR process and reduce the energy barrier for charge transfer and O 2 desorption during OER process, accelerating the ORR/OER kinetics. As a result, the (020) plane-exposed Ag 2 Mo 2 O 7 cathode exhibits ultralong cycle stability of 817 cycles at 500 mA g −1 and large specific discharge/charge capacities of 15898/15180 mAh g −1 . This work provides facile concept guidance for optimizing catalytic capability through controlled lattice distortion in cathode catalysts for LOBs.