Ion-Gel-Driven Electroactive Phase Nucleation in PVDF-TrFE/MoS2 Composites for High-Throughput Triboelectric
Mukul Biswas1, Ritamay Bhunia2, Rahul Mondal3
1Department of Condensed Matter and Materials Physics, S.N. Bose National Centre for Basic Sciences, JD Block, Sector-III, Salt Lake City, Kolkata 700106, India.
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Triboelectric nanogenerators (TENGs) serve as multifunctional platforms for low-frequency ambient energy scavenging and self-powered sensing but often suffer from poor charge retention and mechanical durability. Herein, ternary composites (TCs) of MoS2 nanosheets integrated within a PVDF-TrFE/EMIM-TFSI (PMSI) matrix were developed to enhance charge retention by inducing a highly crystalline β-phase (∼85%). The EMIM-TFSI ionic liquid (IL) triggers electroactive β-phase nucleation in pristine PVDF-TrFE (∼61%) by enhancing polymer chain mobility, crystallinity, and dielectric properties. XPS binding-energy shifts reveal strong electrostatic interactions between MoS2 and PVDF-TrFE, inducing partial positive and negative charges on the Mo and F sites, respectively. Subsequently, the blue-shifted FTIR spectra suggest robust H-bonding between PVDF-TrFE (-CH2 groups) and TFSI- (-SO2, oxygen atoms), facilitating effective ionic-electronic coupling. A vertical contact-separation TENG with optimized PMSI@PDMS frictional layers delivers a VOC of ∼600 V, an ISC of ∼5.1 μA, and a power density of ∼4.8 W/m2. The TENG sustains stable output over 50,000 cycles, demonstrating robust durability for reliable energy harvesting. The TENG powers 120 LEDs, charges a capacitor to 8.3 V in 6 s, and operates as a self-powered interface for real-time digit recognition (0-9) and interactive gaming controllers (Simon Says). Driven by a targeted β-phase nucleation strategy, the PMSI-based TENG offers a scalable approach to developing high-output and reliable energy harvesters for expanding IoT ecosystems.
