Ti3CNTx MXene/rGO scaffolds directing the formation of a robust, layered SEI toward high-rate and long-cycle lithium metal batteries

Abstract

The practical usage of lithium (Li) metal anodes has been hindered by the inherent uncontrolled growth of Li dendrites during stripping/plating. Approaching regulation of uniform Li deposition and robust solid-electrolyte interphase (SEI) is of significance. Herein, we utilized the unique surface chemistry of two-dimensional titanium carbonitride (Ti3CNTx) and the three-dimensional reduced graphene oxide (rGO)-based conductive scaffold architecture, to regulate the Li nucleation and SEI. The lithiophilic functional groups on Ti3CNTx improve the charge-transfer-promoted decomposition of LiN(CF3SO2)2 and resulting in the formation of a uniform SEI layer decorated with evenly distributed LiF and ordered layered Li2O, as evidenced by cryogenic transmission electron microscopy. The Ti3CNTx-rGO-Li electrodes based full cells with LiFePO4 guarantee a superior cycling lifespan over 900 cycles with a capacity retention of 77.7% at 30 C. This work demonstrates that through surface engineering and multiscale architecture design, the suppression of Li dendrites and formation of robust SEI layer can be achieved simultaneously.