Nanoenergy Advances

With the advancement of Internet of Things (IoT) technology, flexible sensors with dual optoelectronic sensing modes have emerged as a research hotspot for next-generation smart devices, further driving the urgent demand for environmentally friendly functional materials. Here, we innovatively integrated wastepaper recycling technology with a polyethyleneimine (PEI)-assisted pulping strategy to develop a novel cellulose-based sustainable photo-triboelectric hybrid nanogenerator (PT-HNG). Based on the working mechanism of a freestanding triboelectric nanogenerator (TENG), the PT-HNG can directly convert pressure stimuli into electrical energy and triboelectrification-induced electroluminescence (TIEL) signals. It achieves luminescence brightness of 0.06 mW cm⁻² (3.84 cd m⁻²) and simultaneously delivers excellent electrical output performance (172.4 V, 6.36 μA, 43.7 nC) under sliding motion. More importantly, compatible with existing industrial papermaking processes, the PT-HNG is scalable for large-scale production. By combining PT-HNG with deep learning algorithms, a handwritten e-book system based on trajectory recognition was constructed, with a recognition accuracy of up to 95.5%. In addition, real-time intelligent control of PowerPoint presentations via PT-HNG was demonstrated. This study provides a new pathway for converting wastepaper into intelligent products and presents a novel idea for the interdisciplinary integration of the circular economy and advanced electronic technology.

This work deals with the comparative analysis of fluoride coatings, i.e., 5 wt.% AlF₃ and LiF, applied as surface layer of Li-rich Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ (LNCM) layered oxides synthesized via facile and cost-effective sol–gel route. The detailed structural and morphological characterizations demonstrate that AlF₃ and LiF deposits have a pivotal role in enhancing the electrochemical properties of LNCM. These electrochemical properties include galvanostatic charge–discharge (GCD), differential capacity (dQ/dV), electrochemical impedance spectroscopy (EIS), and area-specific impedance (ASI). A much lower decay of the discharge capacity of 0.22 and 0.25 mAh g⁻¹ per cycle was obtained for AlF₃- and LiF-coated LMNC, respectively, after 100 charge/discharge cycles at 0.1 C compared with 0.42 mAh g⁻¹ per cycle for pristine LNCM. Results evidence the non-evolution of the charge transfer resistance, enhanced lithium-ion kinetics and stabilization of electrode/electrolyte interface during cycling.

Tungsten oxide (WO₃) nanostructures have emerged as promising electroactive materials due to their high pseudocapacitance, structural versatility, and chemical stability, while reduced graphene oxide (rGO) provides excellent electrical conductivity and surface area. The strategic combination of these nanomaterials in hybrid electrodes has gained attention for enhancing the energy storage performance of supercapacitors. In this work, we report the fabrication and electrochemical performance of nanostructured multilayer films based on the electrostatic Layer-by-Layer (LbL) self-assembly of poly (amidoamine) (PAMAM) dendrimers alternated with tungsten oxide (WO₃) nanofibers dispersed in reduced graphene oxide (rGO). The films were deposited onto indium tin oxide (ITO) substrates and subsequently subjected to electrochemical reduction. UV-Vis spectroscopy confirmed the linear growth of the multilayers, while atomic force microscopy (AFM) revealed homogeneous surface morphology and thickness control. Electrochemical characterization by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) revealed a predominantly electrical double-layer capacitive (EDLC) behavior. From the GCD measurements (PAMAM/rGO-WO₃)₂₀ films achieved an areal capacitance of ≈2.20 mF·cm⁻², delivering an areal energy density of ≈0.17 µWh·cm⁻² and an areal power density of ≈2.10 µW·cm⁻², demonstrating efficient charge storage in an ultrathin electrode architecture. These results show that the synergistic integration of PAMAM dendrimers, reduced graphene oxide, and WO₃ nanofibers yields a promising strategy for designing high-performance electrode materials for next-generation supercapacitors.