image: Bidirectional ion–electric field synergy via in situ grown BiOCl/Bi heterostructure enabling ultra–stable zinc anodes across wide temperatures
Credit: ©Science China Press
For years, the promise of safe, low-cost, and eco–friendly aqueous zinc–ion batteries (AZIBs) for large–scale energy storage has been just out of reach. The technology's Achilles' heel has been the Zn anode itself, which is plagued by internal short–circuits from dendrite growth and energy–wasting side reactions–problems that worsen in hot or cold weather.
Now, researchers have engineered an elegant and robust solution that finally tames the volatile zinc anode. By constructing a self–forming, dual–action Bi/BiOCl protective layer, they have created an anode capable of unprecedented performance and resilience.
This advanced interface works by establishing a powerful bidirectional regulation system. A built–in electric field from the BiOCl layer acts like an invisible shield, guiding zinc ions to deposit smoothly and evenly to prevent destructive dendrites. Simultaneously, it creates an energetic barrier that halts parasitic hydrogen reactions. Complementing this, metallic Bi sites act as magnets for zinc ions, dramatically lowering the energy needed for the battery to charge and discharge efficiently.
The results are a testament to the design's success. The engineered anode enables batteries to cycle for over 2500 hours under demanding conditions. Most critically, it demonstrates exceptional stability across a wide operational window, from a scorching 70 °C to a freezing –20 °C. A full battery based on this technology achieved over 1000 high–speed cycles, while a hybrid capacitor version endured over 15,000 cycles.
This breakthrough addresses the major hurdle for AZIBs, positioning them as a leading contender for practical, grid–scale applications. By ensuring consistent and reliable performance regardless of the temperature, this technology could accelerate the transition to a more sustainable and resilient energy future.