A facile and robust route to polyvinyl alcohol-based triboelectric nanogenerator containing flame-retardant polyelectrolyte with improved output performance and fire safety

Interfacial Polarization and Dual Charge Transfer Induced High Permittivity of Carbon Dots‐Based Composite as Humidity‐Resistant Tribomaterial for Efficient Biomechanical Energy Harvesting

“…The optimized CPP‐TENGs deliver a highest power density of 1.71 W m −2 at an external resistance of 6 MΩ under a force of 100 N with a frequency of 3 Hz, which is 28.5 times higher than pure PVA‐based TENGs (0.06 W m −2 ) (Figure 3f and Figure S13, Supporting Information). Moreover, CPP‐TENGs can even deliver a power density of 1.391 W m −2 under a small impact force of 10 N at a frequency of 3 Hz (Figure S14, Supporting Information), which is still higher than previously reported PVA‐based TENGs [ 47,60–66 ] (Figure 3g and Table S1, Supporting Information). To evaluate the reliability of CPP‐TENGs in practical applications, the output durability and stability of the optimized CPP‐TENGs were tested under a force of 100 N with a frequency of 3 Hz.…”

“…Owing to the presence of abundant hydrophilic groups, water molecules can be spontaneously adsorbed onto the surface of CPP composite to form a water membrane. At high humidity, polycation PEI will dissociate into a fixed‐charge polymer chain and attract mobile anions (OH − ) on electrovalent bond [ 47,54 ] (Figure 1c‐II). When CPP composite contacts the counterpart (PDMS), water membrane is regarded as a water bridge to provide a transfer channel for mobile ions.…”

“…The clusters may deteriorate moisture absorption ability and decrease the mobility of mobile ions. Meanwhile, with the increase of NCDs‐PEI concentration, the effective quantity of PVA chains served as electron donors will be also reduced, [ 47 ] resulting in a further reduction of surface charge density. In addition, it has been reported that the surface potential of triboelectric materials is highly correlative with the electrical performance of TENGs.…”

“…[ 45 ] The amino (NH 2 ) at the terminal of PEI, an outstanding electron‐donating group, [ 46 ] can be used to enhance surface charge density of tribomaterials and improve the electric performance of TENGs. Additionally, PEI has been proven to dissociate into fixed‐charge polymer chains and draw mobile ions, [ 47 ] in which mobile ions as additional charges to further increase surface charge density of tribomaterials. Thus, PEI is an ideal candidate as surface functional moiety of CDs for developing high‐output TENGs.…”

Multifunctional and Physically Transient Supercapacitors, Triboelectric Nanogenerators, and Capacitive Sensors

“…In this work, a flame-retardant biodegradable polyelectrolyte was fabricated by doping PVA with phosphonic acid and branched polyethyleneimine and polyvinylidene fluoride (PVDF) was used as the counter layer with limited biodegradability. [46] A self-powered triboelectric nanogenerator was demonstrated for electronic skin applications interfacing human-machine interactions and monitoring physiological signals and joint movements using PVA and PLGA sandwiching a Ag nanowire network. [16] Even though the materials were biocompatible and harmless to the environment, transiency aspects were not explored.…”