Cellulose Nanofiber/Mxene-Agnws Double Layered Composite Films for Efficient Electromagnetic Interference Shielding, Triboelectric Energy Harvesting, and Thermal Management

Integrating multifunctional characteristics into one flexible electromagnetic interference (EMI) shielding material is highly desirable in improving their working performances and holding a broad range of modern applications. To simultaneously promote EMI shielding efficiency with integrated thermal management and triboelectric energy harvesting, we fabricated cellulose nanofiber-MXene/silver nanowire (CMA) composite film with a double-layered structure by the simple two-step vacuum-assisted filtration process. Contributed by the unique synergism generated from the combination of two different nanofillers, the obtained double-layered CMA composite (dCMA) film possesses satisfying EMI shielding effectiveness (EMI SE) of 67 dB and in-plane thermal conductivity of 12.3 W/mK while maintaining the excellent electrical conductivity of 2515 S/cm with desirable mechanical strength and thermal durability. Compared with homogeneously mixed composite films, the dCMA film delivers excellent electrical conductivity, EMI shielding efficiency and thermal management performance. More importantly, dCMA-based triboelectric nanogenerator (TENG) can generate a maximum open-circuit voltage of 489 V and short-circuit current of ~14.9 μA with a maximum power of 686.4 μW that can successfully power up portable electronics by harvesting energy from simple hand tapping motion. Collectively, our developed dCMA films hold promising potential for a wide range of commercial applications in multifunctional thermally conductive EMI shielding and energy harvesting.