Electronic 'Bridge' Construction via Ag Intercalation to Diminish Catalytic Anisotropy for 2D Tin Diselenide Cathode Catalyst in Lithium–Oxygen Batteries

摘要

As cathode catalysts for lithium–oxygen batteries (LOBs), 2D materials areattracting significant attention due to their layered structures, tunable surfacechemistry, and unique electronic states. However, catalytic anisotropy,particularly the poor catalytic capability of the van der Waals forces containedin stack edge planes, has suppressed the enhancement of LOB performanceas 2D cathode catalysts. Here, an ion-intercalation strategy is proposed todiminish the catalytic anisotropy of 2D materials. Ag ions are successfullyintercalated into SnSe_2 layered structure and regulate the electronic statesbetween stack edge planes, leading to an improvement in the catalyticcapability of 2D SnSe_2. Notably, the catalytic capability of the 2D surface (001)plane of SnSe_2 is also significantly enhanced after Ag intercalation, whichcan efficiently accelerate charge transfer and suppress the passivation on the2D surface plane during the oxygen reduction/evolution reaction process. Asa consequence, the Ag-intercalated SnSe_2 cathode exhibits superior specificcapacity of 16871 mAh g~(?1) and an ultrastable cycle life over 2300 h at a currentdensity of 100 mA g~(?1) and 144 cycles at current density of 1000 mA g~(?1). Thiswork provides insights into the modulation of the catalytic capabilities of2D materials, which have significant potential for this application in LOBs.