rGO-based artificial protective membrane modified with CTAB for stable sodium metal anode

Next-generation sodium-ion batteries (NIBs) require high energy densities and long-term cycling materials to achieve widespread applications. Although Na metal is one interesting candidate due to its theoretical specific capacity of 1165 mAh g −1 , the uncontrollable growth of Na dendrites and unstable surface during cycling prohibit practical implementation. For example, the inhomogeneous Na deposition and repeated formation of the solid electrolyte interphase are among the most significant issues related to the unstable surface in Na metal anodes, leading to continuous electrolyte depletion and poor cycling performance. This work develops a reduced graphene oxide (rGO) membrane containing cetyltrimethylammonium bromide (CTAB), which is applied as an artificial protective layer for NIBs. Compared with the bare Na, the designed membrane (CTAB-rGO) avoids the uneven Na deposition and unstable electrolyte/electrode interface, while enhancing the interfacial charge transfer. Incorporating CTAB into the rGO contributes to a higher stable cycling up to 1200 h and a lower Na nucleation overpotential than the rGO membrane and bare Na metal electrode. The Na 3 V 2 (PO 4 ) 3 |CTAB-rGO/Na metal full cell maintains a stable cycling performance after 120 cycles, retaining a specific capacity of 94.4% without short circuiting.