Boosting green EMI shielding and piezoelectric energy generation by defect-driven microstructure manipulation

Abstract

The rapid proliferation of sophisticated wireless industrial and remote sensing systems with limited power sources has created a need for the development of piezoelectric energy harvesting materials (PEHMs) with electromagnetic interference (EMI) shielding properties to ensure secure and reliable operations. Herein, a polydimethylsiloxane (PDMS)/single walled carbon nanotube (SWCNT)/graphitic carbon nitride doped lithium potassium niobate (GNLKN) based PEHM with excellent EMI shielding capability has been prepared. In contrast to the PDMS/LKN-based PEHM, which has a potential of 19.6 V, a current of 24.26 nA, and a power density of 29.7 nW cm⁻², the PDMS/GNLKN-based PEHM provides an astounding potential of 49.57 V, a current of 59.4 nA, and a power density of 188.4 nW cm⁻². Additionally, composites based on PDMS/SWCNT/GNLKN with regulated excluded volume exhibit an improved shielding performance of ∼85 dB by adjusting the excluded volume and SWCNT concentrations. The green index value of more than one for the composites signifies environmentally friendly absorption-controlled shielding efficacy with restricted reflection.