近期，我院研究生谢自浩（第一作者）、教师贺德清（通讯作者）、苏超（通讯作者）等的研究成果“A Potassium-Doped Perovskite-Based Nanocomposite as an Efficient Bifunctional Oxygen Electrocatalyst for Rechargeable Zn-Air Batteries”在材料科学TOP期刊《Small》（IF=13.0）上发表。
论文简介如下：
双功能氧电催化剂对可充电锌-空电池（ZABs）的性能起着至关重要的作用，直接影响到电池的容量、往返效率和耐用性等关键参数。理想的ZABs空气电极电催化剂必须在碱性介质中对氧还原和氧析出反应都具有高的催化活性。本研究提出了一种钾离子掺杂策略来设计钙钛矿氧化物主相的电子和缺陷结构，促进相分离，形成由钙钛矿相和具有共生结构的二次相组成的纳米复合材料。所制备的纳米复合催化剂表现出Co3+和氧空位浓度增加、亲水性增强、氧中间体吸附改善等特点。结果表明，具有优化组成的催化剂能够实现优异的双功能催化活性和耐久性，从而延长了ZABs的循环稳定性和提高了能量转换效率。值得注意的是，与无钾的原始催化剂相比，它的功率密度增加了42%，电压间隙减小（ΔE = 0.83 V），循环寿命延长超过250 h。这项工作通过钾离子掺杂促进钙钛矿氧化物的缺陷工程异质结构的生成，为先进的金属-空气电池催化剂引入了一种新的设计思路。
Bifunctional oxygen electrocatalysts play a crucial role in the performance of rechargeable zinc-air batteries (ZABs), directly impacting key parameters such as capacity, round-trip efficiency, and durability. The ideal electrocatalysts for ZAB air electrodes must exhibit high catalytic activity for both oxygen reduction and oxygen evolution reactions in alkaline medium. This study presents a potassium-ion doping strategy to engineer the electron and defect structures of the perovskite oxide main phase, promoting phase separation to form a nanocomposite consisting of a perovskite phase and a secondary phase with an intergrowth structure. The resulting nanocomposite catalyst exhibits increased concentrations of Co3+ and oxygen vacancies, enhanced hydrophilicity, and improved adsorption of oxygen intermediates. As a result, the catalyst with the optimized composition demonstrates exceptional bifunctional activity and superior durability, leading to extended cycling stability and improved energy conversion efficiency in ZABs. Notably, it achieves a 42% increase in power density compared to the potassium-free pristine catalyst, a reduced voltage gap (ΔE = 0.83 V), and an extended cycle life of over 250 hours. This work introduces a novel design paradigm for advanced metal-air battery catalysts through potassium-promoted defect-engineered heterostructure manipulation of perovskite oxides.
