Challenges and strategies for ultrafast aqueous zinc-ion batteries

With the rising demand for fast-charging technology in electric vehicles and portable devices, significant efforts have been devoted to the development of the high-rate batteries. Among numerous candidates, rechargeable aqueous zinc-ion batteries (ZIBs) are a promising option due to its high theoretical capacity, low redox potential of zinc metal anode and inherent high ionic conductivity of aqueous electrolyte. As the strong electrostatic interaction between Zn²⁺ and host generally leads to sluggish electrode kinetics, many strategies have been proposed to enhance fast (dis)charging performance. Herein, we review the state-of-the-art ultrafast aqueous ZIBs and focus on the rational electrode-designing strategies, such as crystal structure engineering, nanostructuring and morphology controlling, conductive materials introducing and organic molecule designing. Recent research directions and future perspectives are also proposed in this review.