Tin-Modified MXene Composite Electrodes as Lithiophilic Hosts for Stable Lithium Metal Anodes

Lithium metal anodes provide a tenfold higher theoretical capacity than graphite but face issues such as dendritic growth, unstable solid–electrolyte interphases (SEIs), large volume changes, and “dead” lithium formation, which limit their practical application. In this work, a Sn-modified Ti3C2Tx MXene host (Sn@MX) is introduced to combine the lamellar architecture of MXene with Sn-derived lithiophilic sites, enabling controlled lithium deposition. The Sn@MX material was prepared through precursor-assisted expansion of MXene lamellae followed by incorporation of Sn-containing species. Electrochemical testing using the reservoir method shows that Sn@MX maintains stable plating and stripping for over 120 cycles at 1 mA cm−2, unlike copper and untreated MXene electrodes, which fail rapidly. Ex situ and operando optical microscopy indicate that lithium preferentially deposits within the Sn@MX electrode structure, resulting in more uniform deposition and reduced dendritic growth. These results emphasize the importance of combining porous lamellar architectures with lithiophilic sites to develop stable lithium metal anodes for advanced batteries.