Synergistic Integration of MgAl-LDH Nanosheets into Bacterial Cellulose for High-Performance Triboelectric Nanogenerators

A novel nanocomposite design is presented in which magnesium aluminum layered double hydroxide (MgAl-LDH) nanosheets are synergistically integrated with bacterial cellulose (BC) to fabricate a flexible triboelectric nanogenerator (TENG). Utilizing a facile solution synthesis combined with a casting process, composite films with controlled MgAl-LDH loadings (0.25–5% v/v) were developed. The optimal composite, containing 1.5% v/v MgAl-LDH, exhibits an open-circuit voltage (VOC) of 88.5 V, a short-circuit current (ISC) of 87.7 μA, and a maximum output power (Pmax) of 1250 μW (power density ≈138 μW/cm²), which is > 35 times higher than that of pristine BC. Notably, this performance corresponds to a superior filler efficiency metric, demonstrating a highly effective use of the nanosheet additive compared to other reported systems. This performance enhancement is attributed to the multifunctional role of MgAl-LDH nanosheets in increasing the dielectric constant through improved interfacial conductivity and the formation of parallel microcapacitors under an induced electric field. Finite element simulations corroborate the proposed mechanism, and practical demonstrations show the nanocomposite powering 200 LEDs as well as functioning as a self-powered sensor for finger movement monitoring. These findings advance the development of high-performance, flexible energy-harvesting devices.