Mitigating ion flux vortex enables reversible zinc electrodeposition

Metal anodes hold considerable promise for high-energy-density batteries but are fundamentally limited by electrochemical irreversibility caused by uneven metal deposition and dendrite formation, which compromise battery lifespan and safety. The chaotic ion flow (or ion flux vortex) near the electrode surface, driving these instabilities, has remained elusive due to limitations in conventional techniques such as scanning electron and atomic force microscopies, which are invasive and incapable of probing internal structures of deposits. Here, we employ in-situ X-ray computed tomography (CT) to non-destructively visualize Zn deposition on LAPONITE-coated Zn anodes, thereby revealing the internal structural evolution and deposition orientation. Combined with computational fluid dynamics simulations, we demonstrate that the LAPONITE coating, with its separated positive and negative charge centers, suppresses ionic vortex formation, guiding uniform, dense, and vertically aligned Zn growth along (100) plane, thereby significantly mitigating dendrite growth. This translates into a 3.17-Ah Zn-MnO2 pouch cell with stable performance over 100 cycles, offering a viable path toward scalable, high-performance metal-anode batteries.