电子轴向拉伸提升贫氧环境海水电池性能

Molecular catalysts with electronic axial stretching for high-performance lean-oxygen seawater batteries

长寿命溶解氧海水电池是深远海观测能源网络的重要组成单元,但海水贫氧复杂环境对设计高性能氧还原催化剂提出了重要挑战.本文以酞菁铁为模型催化剂,通过理论计算与实验验证,提出了活性位点电子轴向拉伸可大幅提升催化剂在极端贫氧环境中的氧还原活性和稳定性.该研究为构建高性能海水电池提供了材料学解决方案,同时为极端环境下催化剂的变革性设计提供了新的思路.

A dissolved-oxygen seawater battery(SWB)can generate electricity by reducing dissolved oxygen and sacrificing the metal anode at different depths and temperatures in the ocean,acting as the basic unit of spatially underwater energy networks for future maritime exploration.However,most traditional oxygen reduction reaction(ORR)catalysts are out of work at such ultralow dissolved oxygen concentration.Here,we proposed that the electronic axial stretching of the catalyst is essentially responsible for enhancing the catalyst’s sensitivity to dissolved oxygen.By modulating the lattice of iron phthalocyanine(FePc)as a model catalyst,the unique electronic axial stretching in the z-direction of planar FePc molecules was realized to achieve a boosted adsorption and electron transfer and result in a much improved ORR activity in lean-oxygen seawater environment.The peak power density of a homemade SWB using a practical carbon brush electrode decorated by the FePc is estimated to be as high as 3 W L^(-1).These results provide inspiring insights into the interaction between the catalyst and complicated seawater environment,and propose the electronic axial stretching as an effective indicator for the rational design of catalysts to be used in extremely lean-oxygen environment.