Abstract: The vigorous development of modern electronic communication demands multi-functional materials with exceptional electromagnetic interference (EMI) shielding. However, constructing lightweight and highly efficient metal-free carbon-based EMI shielding materials remains a huge challenge, particularly with robust EMI responses across a broadband frequency. Herein, a broadband (8-27 GHz) and strong EMI shielding response nitrogen-doped carbon plate (NCP) is constructed by a pressing and two-step pyrolysis process. The layered stacking structure and N-doping impart extraordinary EMI shielding performance to the carbon plate, achieving EMI shielding effectiveness values of 82.60, 95.44, and 104.12 dB in the X band, Ku band, and K band, respectively. Notably, the overall thickness of NCP was <1 mm. Moreover, the NCP exhibits remarkable joule heating performance with a low driving voltage (≤3 V) and a fast electrothermal response. This work enables the potential for the development of metal-free carbon materials with lightweight, highly efficient and broadband-strong EMI shielding performance.

Key words: Carbon plate, Nitrogen-doped, Electromagnetic shielding, Broadband frequency, Joule heating performance