High-Throughput Electrospinning System| High-performance triboelectricnanogenerators doped with carbonnanomaterials derived from cobalt-nickelbimetallic organic frameworks forharvesting low-frequency mechanicalenergy

Suzhou University Prof. Wang Ping & Prof. Zhang Yan: Highly Electronegative Electrospun Membranes for Triboelectric Nanogenerators

With the rapid development of IoT and AI technologies, portable electronics have gained significant attention for improving quality of life. Sustainable energy solutions are crucial for persistent hardware operation and distributed power needs in IoT, making energy harvesting a key to entering the smart era. Triboelectric nanogenerators (TENGs), capable of collecting low-frequency mechanical energy, are among the best choices for next-generation energy solutions.

Recently, Suzhou University’s Prof. Wang Ping and Prof. Zhang Yan published research in Chemical Engineering Journal titled "High-performance triboelectric nanogenerators doped with carbon nanomaterials derived from cobalt-nickel bimetallic organic frameworks for harvesting low-frequency mechanical energy." The team fabricated a highly electronegative polyvinylidene fluoride (PVDF) composite nanofiber membrane (CNF) via single-needle electrospinning, incorporating metal-organic framework (MOF)-derived CoNi-NC nanomaterials. Compared to pure PVDF nanofibers, the CoNi-NC/PVDF CNF exhibited superior triboelectric performance.

The cobalt-nickel carbon framework nanomaterials (CoNi-NC) were obtained through high-temperature carbonization, during which the carbonization of organic components led to surface shrinkage and partial structural collapse while largely maintaining the original framework. The metallic cobalt and nickel remained uniformly distributed across the surface, with particle sizes averaging 400±50 nm.

Figure 1: Morphology of CoNi-NC and its doping effect in PVDF.

The incorporation of CoNi-NC significantly enhances both the content of the more electronegative β-phase in PVDF and its dielectric properties. Under the synergistic effects of the high-voltage electrospinning field and filler incorporation, the β-phase formation is further promoted, as quantitatively verified through Fourier-transform infrared spectroscopy (FTIR).

Figure 2: β-phase content and dielectric properties.

Benefiting from the synergistic effect of bimetals, exposed active sites as well as high stability and conductivity are demonstrated. These uniformly distributed metal nodes serve as multiple charge carrier transfer pathways to accelerate electron emission. The TENG assembled with CoNi-NC/PVDF CNF not only shows significantly improved electrical output performance, but also possesses durability and stability for up to two hours of operation.

Figure 3: TENG performance.

In addition, it possesses powerful energy harvesting capability, and after bridge rectification can drive small low-power electronic devices and series-connected light-emitting diodes. Finally, the potential of TENG in self-powered touch devices was also investigated, providing direction for further application development.

Figure 4: Applications.