Highly flexible, porous electroactive biocomposite as attractive tribopositive material for advancing high-performance triboelectric nanogenerator

The triboelectric property of the tribomaterials is essential for high-performance triboelectric nanogenerators (TENGs). Currently, the available tribopositive material is still limited and there is a strong need to explore attractive tribomaterials with high positive tribopolarity, biocompatibility, and easy preparation. Herein, we proposed porous cellulose acetate (CA)-polyethyleneimine (PEI) biocomposite (CP biocomposite) and employed it as an effective tribopositive material, paired with flexible low-temperature vulcanized silicone rubber (LTV) tribonegative membrane, to develop high-output CP/LTV-TENG. The mass ratio of CA/PEI and thickness of CP biocomposite were optimized systematically, and the CP biocomposite with CA/PEI mass ratio of 3:1 and the thickness of 55 μm is recognized as an optimal sample. The corresponding CP/LTV-TENG could deliver the open-circuit voltage (VOC) of 478 V, short-circuit current density (JSC) of 6.3 μA/cm2, and power density of 2.21 mW/cm2 under the applied force of 16 N and frequency of 1.5 Hz, much higher than that of CA membrane-based CA/LTV-TENG. Further, the mechanism for the improved working performance of CP/LTV-TENG was discussed, and it revealed that the synergistic effect of surface electron-donating ability and inner porous structure of CP biocomposite is mainly responsible for the high electrical performance. Additionally, the CP/LTV-TENG presented outstanding electrical output stability and durability, and it is effectively capable of powering electronics and performing movement detection. This work confirms the feasibility of the proposed CP biocomposite as effective tribopositive material for developing high-power TENGs and offers insights for designing novel bio-tribomaterial in the advancement of eco-friendly TENGs.