Multifunctional bamboo-derived porous carbon for efficient electrical-thermal energy management and electromagnetic interference shielding

Abstract

Joule heating is an effective heating method but is often limited by the extra heat dissipation. To address this, we developed bamboo-derived porous carbon (CB) for use as Joule heaters, which exhibits remarkable electrothermal conversion efficiency, driven by its high electrical conductivity and porous structure. The natural porous structure of bamboo reduces electrothermal conversion losses, allowing for a steady-state saturation temperature of 164 °C at 2 V. The microcrystalline graphite structure, 3D microporous channels, and low thermal conductivity (0.03 W m⁻¹ k⁻¹) contribute to an electrothermal conversion efficiency of 99.14 %. Moreover, CB heaters demonstrate remarkable surface heating and cooling rates of 114.36 °C/min and 113.78 °C/min, respectively. CB Joule heaters are suitable for de-icing and body-assisted heat treatment at various applied voltages. Its unique gradient porous structure also provides asymmetrical electromagnetic interference (EMI) shielding performance, with high absorption losses concentrated in the sparse inner layer. This sustainable CB material has significant potential for advanced Joule heating and EMI shielding applications.