Resting-Potential-Inspired Solid-State Iontronic Osmotic Power Source Enabled by Polarized MXene

Abstract Bio-inspired osmotic energy has shown great potential as a portable energy source or artificial electrical organ for green and sustainable power generation. However, ion-electron decoupling problem and complex structures resulting from over-engineering often limit output power and portability. Here, we propose a comprehensive design strategy that exploits the unique ion-electron coupling properties of polarized MXene to mimic transmembrane ion transport at resting potential, thereby developing an all-MXene solid-state iontronics osmotic power source (IOPS). Density functional theory calculations and multiscale characterizations reveal that its operating mechanism is based on the diffusion dynamics of K + under a concentration gradient and the Fermi level difference between two polarized MXene electrodes. The device achieves an initial open-circuit voltage exceeding 0.57 V and a high volumetric power density of 1030 μW cm −3 . The highly integrated architecture of the IOPS module allows for straightforward scalability and reconfiguration to power commercial electronic devices. This work integrates the principles of biological ion gradients with emerging iontronics, providing a solid-state iontronic design strategy for compact osmotic power source. Here, taking the natural resting potential as a design blueprint, we report a solid-state iontronic osmotic energy generator, termed IOPS, which fully leverages the ion–electron coupling effect in polarized MXene. Its mechanism arises from the diffusion kinetics of K + under an ion gradient and the Fermi level difference between two distinct polarized MXenes at the positive and negative electrodes. An initial open-circuit voltage exceeding 0.57 V and a high volumetric power density of 1030 μW cm -3 were achieved. This work integrates the fundamental principles of biological ion gradients with emerging iontronics technology, offering a paradigm for the practical deployment of osmotic energy.