Magnesium batteries have long been pursued as potentially low-cost, high-energy and safe alternatives to Li-ion batteries. However, Mg²⁺ interacts strongly with electrolyte solutions and cathode materials, leading to sluggish ion dissociation and diffusion, and consequently low power output. Here we report a heterogeneous enolization chemistry involving carbonyl reduction (C=O↔C–O⁻), which bypasses the dissociation and diffusion difficulties, enabling fast and reversible redox processes. This kinetically favoured cathode is coupled with a tailored, weakly coordinating boron cluster-based electrolyte that allows for dendrite-free Mg plating/stripping at a current density of 20 mA cm⁻². The combination affords a Mg battery that delivers a specific power of up to 30.4 kW kg⁻¹, nearly two orders of magnitude higher than that of state-of-the-art Mg batteries. The cathode and electrolyte chemistries elucidated here propel the development of magnesium batteries and would accelerate the adoption of this low-cost and safe battery technology.

长期以来，镁电池一直是锂离子电池的潜在低成本，高能量和安全替代品。然而，Mg ²⁺与电解质溶液和阴极材料强烈相互作用，导致缓慢的离子解离和扩散，从而导致低功率输出。在这里，我们报告涉及羰基还原（C =O↔C-O异构的烯醇化化学^- ），它绕过解离和扩散的困难，可实现快速和可逆的氧化还原过程。此动力学上受好评的阴极与量身定制的，弱配位的基于硼团簇的电解质相结合，该电解质可在20 mA cm ^-2的电流密度下进行无枝晶的Mg电镀/剥离。这种结合提供了一种Mg电池，其比功率高达30.4 kW kg ^-1，比最先进的Mg电池高出近两个数量级。此处阐明的阴极和电解质化学物质推动了镁电池的发展，并将加速采用这种低成本，安全的电池技术。