A nanogenerator based on metal nanoparticles and magnetic ionic gradients

Developing a new technique/method and/or mechanism for separating ionic charges is critical to the fabrication of a high-performance nanogenerator. Inspired by charge migration and/or separation under an electric bias, herein, we demonstrate a reverse process in which the ionic charge gradients within a metal nanoparticle film are used to output electrical energy. The metal nanoparticle core is ‘jammed’ within the film, while the counterion itself is mobile and magnetic; therefore, ionic gradients are created through an external magnetic field. The distribution gradient of magnetic counterions is subsequently transformed into an electric potential within the metal nanoparticle film and into an electron flow in the external circuit. The performance of the nanoparticle nanogenerator is also optimized, and the highest output open-circuit voltage reaches 0.55 V. Finally, we develop a continuum charge-transport model combining Poisson and Nernst‒Planck diffusion equations to simulate the production of electrical energy within metal nanoparticle films.