Hollow Porous Nitrogen-Doped Carbon-Confined FeP/Fe2P Nanoparticle-Armored Catalyst for Efficient Oxygen Reduction Reaction in Aqueous/Flexible Zinc-Air Batteries

en This link goes to a English section zh This link goes to a Chinese section The design of nanoparticles confined in hollow N-doped carbon structures is crucial for improving the oxygen reduction reaction (ORR) kinetics, yet achieving this remains a significant challenge. In this work, hollow porous nitrogen-doped carbon encapsulated FeP/Fe 2 P (H-FeP/Fe 2 P) were successfully constructed via a templating method combined with dopamine hydrochloride coating, acid etching, and subsequent high-temperature phosphating. In situ spectroelectrochemical investigations and theoretical results demonstrate that the adsorbed hydroxyl species (*OH) can be readily released from the catalyst surface by facilitating the dissociation of oxygen–oxygen bonds at the active sites of Fe, thus accelerating the kinetics of the ORR. The optimized H-FeP/Fe 2 P achieves a high limiting current density of 5.5 mA cm −2 and a low Tafel slope of 39 mV dec −1 in 0.1 M KOH, outperforming corresponding solid samples and most reported transition metal phosphide catalysts. Moreover, the H-FeP/Fe 2 P-based aqueous ZAB exhibits remarkable performance, including high peak power density (175 mW cm −2 ), large specific capacity (813 mAh g −1 Zn ), and stable charge/discharge stability over 800 h. The corresponding solid-state zinc-air battery also delivers a high peak power density of 101 mW cm −2 and excellent flexibility. The carbon confinement strategy proposed in this study opens new avenues for developing high-performance and cost-effective non-precious metal ORR catalysts in zinc-air batteries. 摘要 en This link goes to a English section zh This link goes to a Chinese section 将纳米颗粒限域于中空氮掺杂碳结构中的设计对提升氧还原反应(ORR)动力学性能至关重要,但实现这一目标是一个重大挑战。本研究通过模板法结合盐酸多巴胺包覆、酸蚀刻及后续高温磷化工艺,成功构建了中空多孔氮掺杂碳封装FeP/Fe 2 P(H-FeP/Fe 2 P)。原位光谱电化学研究与理论计算结果表明,通过促进Fe活性位点处氧-氧键的解离,吸附羟基物种(*OH)可从催化剂表面顺利脱附,进而加快ORR的反应动力学。优化后的H-FeP/Fe 2 P在0.1 M KOH电解液中展现出优异的ORR性能,极限电流密度高达5.5 mA cm −2 ,塔菲尔斜率低至39 mV dec −1 ,其性能优于对应的实心结构样品及多数已报道的过渡金属磷化物催化剂。此外,基于H-FeP/Fe 2 P的水系锌-空气电池(ZAB)同样表现出卓越的性能,包括175 mW cm −2 的高峰值功率密度、813 mAh g −1 Zn 的大比容量,以及超过800 h的稳定充放电性能。相应的固态锌-空气电池也具备101 mW cm −2 的高峰值功率密度和出色的柔韧性。本研究提出的碳限域策略,为开发锌-空气电池中高性能、低成本的非贵金属ORR催化剂开辟了新途径。