近日，武汉大学晏宁团队研究了一种双功能催化剂实现负载柔性电-氢互转化的可逆碱性水电解槽。该项研究成果发表在2025年8月12日出版的《国家科学评论》杂志上。

安全、高效、经济的电网级电化学储能系统是实现可再生能源高水平并网的必要条件。氢作为一种理想的能量载体，可以通过水电解产生，并通过燃料电池转换回电能。尽管传统的碱性水电解槽是最先进的，而且成本相对较低，但基于膜的燃料电池在资本和运营费用方面通常都很昂贵。

研究组开发了一个单室，无膜碱性水电解槽，实现可逆的电能到氢气的转化。NiOOH氧化还原介质夹在两个双功能电极（一个用于氢氧化和氧还原反应，另一个用于氢逸出和氧逸出反应）之间，在防止H₂-O₂气体混合物形成的同时，绕过了离子导电膜的主题。由于阳极和阴极反应解耦，在高电流密度（>500 mA cm^-2）和低电流密度（<50 mA cm^-2）下都能产生高纯度H₂ (>99%)，具有出色的负载灵活性。

重要的是，该电解槽可作为燃料电池有效地可逆工作，峰值功率密度为0.23 W cm^-2。此外，它还能够作为Ni-H₂电池进行短时间储能，峰值功率密度为1.4 W cm^-2，往返效率83.6%。电解槽在不同的工作模式之间轻松切换，同时在350小时的耐久性测试中保持优异的性能。

附：英文原文

Title: A reversible alkaline water electrolyzer for load-flexible power-H2 interconversion enabled by bifunctional catalyst

Author: Yan, Xiaoyu, Zhao, Yang, Ke, Le, Wu, Xiaoyu, Zhao, Kai, Li, Lingjiao, Cao, Xiaojuan, Jiang, Xiaoyi, Yang, Ying, Rothenberg, Gadi, Yan, Ning

Issue&Volume: 2025-08-12

Abstract: A safe, efficient and affordable electrochemical energy storage system at the grid scale is necessary for high-level integration of renewable energy. As an ideal energy carrier, hydrogen can be generated via water electrolysis and converted back to electricity via fuel cells. Although conventional alkaline water electrolyzers are robust and relatively cost effective, membrane-based fuel cells are often costly in terms of both capital and operational expenses. Herein, we developed a single-compartment, membrane-free alkaline water electrolyzer, enabling reversible power-to-H2 conversion. The NiOOH redox mediator, sandwiched by two bifunctional electrodes (one for hydrogen oxidation and oxygen reduction reactions and the other for hydrogen evolution and oxygen evolution reactions), circumvented the use of vulnerable ion-conducting membranes while preventing the formation of H2-O2 gas mixtures. Owing to the decoupled anodic and cathodic reactions, high-purity H2 (>99%) was produced at both high (>500 mA cm2) and low current densities (<50 mA cm2), offering excellent load flexibility. Importantly, it effectively works reversibly as a fuel cell, with a peak power density of 0.23 W cm2. In addition, it was also capable of working as a Ni-H2 battery for short-duration energy storage, delivering a peak power density of 1.4 W cm2 and a round-trip efficiency of 83.6%. The electrolyzer was easily switched between different operational modes while retaining excellent performance in a 350 h endurance test.

DOI: 10.1093/nsr/nwaf325

Source: https://dx.doi.org/10.1093/nsr/nwaf325