Wearable electromagnetic interference (EMI) shielding fabrics with excellent electromagnetic shielding performance, oxidation resistance, and structural stability are highly demanded for the rapid development of electronic devices and wireless communication. MXenes are metallic conductive materials with exceptional EMI shielding properties, but they are prone to oxidation in air and have poor structural stability and durability on fabric substrates. Herein, we present a one-step assembly method to fabricate fabrics coated with MXenes and polymeric sodium alginate (SA) composite (MXene-SA). SA protects MXenes from oxidation and forms a stable interlayer structure by bonding to MXenes. The MXene-SA coated fabrics are breathable and flexible, and have a low sheet resistance of 2.12 ± 0.08 Ω/sq and a high EMI shielding performance of 37.05 dB at X-band, which is comparable to the best 42.31 dB. Moreover, the MXene-SA coated fabrics exhibit high structural stability and oxidation resistance under various conditions of sonication disintegration, mechanical abuse, chemical corrosion, and humidity, compared to pure MXenes coated fabrics. We believe that the wearable and high-performance MXene-SA fabrics have great potential for the next generation of ultra-portable and wearable EMI shielding products.

MXenes are two-dimensional transition metal carbides and/or nitrides with unique physiochemical properties and have attracted extensive interest in numerous fields. However, current MXene synthesis methods are limited by hazardous synthesis conditions, high production costs, or difficulty in large-scale production. Therefore, a general, safe, cost-effective, and scalable synthesis method for MXenes is crucial. Here, we report the fast synthesis of MXenes in the open air using a molten salt-shielded synthesis (MS³) method, which uses Lewis-acid salts as etchants and a low-melting-point eutectic salt mixture as the reaction medium and shield to prevent MXene oxidation at high temperatures. Carbide and nitride MXenes, including Ti₃C₂T_x, Ti₂CT_x, Ti₃CNT_x, and Ti₄N₃T_x, were successfully synthesized using the MS³ method. We also present the flexibility of the MS³ method by scaling the etching process to large batches of 20 and 60 g of Ti₃AlC₂ MAX precursor in one pot. When used as negative electrodes, the prepared MS³-MXenes delivered excellent electrochemical properties for high-rate Li-ion storage.