Spatial confinement of vertical arrays of lithiophilic SnS2 nanosheets enables conformal Li nucleation/growth towards dendrite-free Li metal anode

Abstract

The development of next-generation lithium metal batteries (LMBs) has been chronically hindered by uncontrollable dendrite growth and infinite dimension change of metal Li. Even though the porous carbon skeletons have been deemed as effective hosting materials to prepare low-stress Li metal anode (LMA), the lithiophobic feature and poor spatial regulation for Li nucleation/growth of carbon skeletons render the achievement of high-stable LMA to be challenging. Herein, vertical-aligned SnS2 nanosheet arrays (SnS2 NSA) with intrinsic lithiophilic nature, endowed by in situ formed Li13Sn5 via the alloying reaction of SnS2, are uniformly decorated on highly flexible carbon foam (SnS2 NSA@CF) to overcome the encountered issues of ordinary carbon skeletons. The vertical-aligned SnS2 nanosheet offers enriched lithiophilic surface area, thereby guiding the thin Li-nuclei layer uniformly deposited on nanosheet. Moreover, the continuous Li growth is proceeded on the initial Li-nuclei layer and spatially confined into the nanochannels of nanoarray to eliminate the volume change of LMA. The well-defined nanochannel effectively reduces the local current density and provides open spacing for quick charge transfer kinetics. Accordingly, the sustainable Li utilization with high Coulombic efficiency and highly stable Li plating/stripping with low polarization is achieved, shedding light on the feasibility of SnS2 NSA for dendrite-free LMA.