Flexible electromagnetic interference (EMI) shielding materials with excellent thermal conductivities and Joule heating performances are of urgent demand in the communication industry, artificial intelligence, and wearable electronics. In this work, highly conductive silver nanowires (AgNWs) were prepared using the polyol method. Cellulose sheets were then prepared by dissolving natural cotton in a green and efficient NaOH/urea aqueous solution. Finally, multifunctional flexible EMI shielding AgNWs/cellulose films were fabricated based on vacuum-assisted filtration and hot-pressing. AgNWs are evenly embedded in the inner cellulose matrix and overlap with each other to form a 3D network. AgNWs/cellulose films, with a thickness of 44.5 μm, obtain the superior EMI shielding effectiveness of 101 dB, which is the highest value ever reported for shielding materials with the same thickness. In addition, AgNWs/cellulose films present excellent tensile strength (60.7 MPa) and tensile modulus (3.35 GPa), ultrahigh electrical conductivity (σ, 5571 S/cm), and excellent in-plane thermal conductivity coefficient (λ∥, 10.55 W/mK), which can effectively dissipate the heat accumulation. Interestingly, AgNWs/cellulose films also show outstanding Joule heating performances, good stability, and sensitive temperature response at driving voltages, absolutely safe for the human body. Therefore, our fabricated multifunctional flexible AgNWs/cellulose films have broad prospects in the fields of EMI shielding and protection of outdoor large-scale power transformers and wearable electronics.

通讯工业、人工智能和可穿戴电子产品领域亟需具有优异导热性能和焦耳热性能的柔性电磁干扰（EMI）屏蔽材料。本文采用多元醇法制备高导电银纳米线（AgNWs），通过天然棉花溶解于绿色且高效的NaOH/尿素水溶液体系制备纤维素（cellulose）片，再经真空辅助抽滤与热压相结合的方法制备多功能AgNWs/纤维素屏蔽膜。研究结果表明，AgNWs均匀地嵌在纤维素基体中，且相互搭接成三维网络结构。44.5 μm厚度的AgNWs/纤维素屏蔽膜具有101 dB的EMI SE，这是迄今报道过相同厚度下材料中的最高值。此外，AgNWs/纤维素屏蔽膜拥有卓越的拉伸强度（60.7 MPa）和拉伸模量（3.35 GPa），超高的导电率（s，5571 S/cm）和面内导热系数（λ∥，10.55 W/mK），可以有效耗散聚酰亚胺电热膜和陶瓷发热片工作过程中产生的热积聚。更有趣的是，AgNWs/纤维素屏蔽膜还显示出了出色的焦耳热性能，在对人体绝对安全的工作电压下具有良好的稳定性和灵敏的热响应性。因此，这种多功能柔性AgNWs/纤维素薄膜在户外大型变电设备和人体可穿戴设备的EMI屏蔽防护领域的应用具有广阔的前景。