title: Using elastin protein to develop highly efficient air cathodes for lithium-O2 batteries.
abstract: Transition metal-nitrogen/carbon (M-N/C, M = Fe, Co) catalysts are synthesized using environmentally friendly histidine-tag-rich elastin protein beads, metal sulfate and water soluble carbon nanotubes followed by post-annealing and acid leaching processes. The obtained catalysts are used as cathode materials in lithium-O2 batteries. It has been discovered that during discharge, Li2O2 nanoparticles first nucleate and grow around the bead-decorated CNT regions (M-N/C centres) and coat on the catalysts at a high degree of discharge. The Fe-N/C catalyst-based cathodes deliver a capacity of 12,441 mAh g(-1) at a current density of 100 mA g(-1). When they were cycled at a limited capacity of 800 mAh g(-1) at current densities of 200 or 400 mA g(-1), these cathodes showed stable charge voltages of ∼3.65 or 3.90 V, corresponding to energy efficiencies of ∼71.2 or 65.1%, respectively. These results are considerably superior to those of the cathodes based on bare annealed CNTs, which prove that the Fe-N/C catalysts developed here are promising for use in non-aqueous lithium-O2 battery cathodes.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore.
authors.forename: Guilue
authors.initials: G
authors.lastname: Guo
authors.forename: Xin
authors.initials: X
authors.lastname: Yao
authors.forename: Huixiang
authors.initials: H
authors.lastname: Ang
authors.forename: Huiteng
authors.initials: H
authors.lastname: Tan
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Guo
authors.forename: Eileen
authors.initials: E
authors.lastname: Fong
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Yan
mesh_terms: D002384:Catalysis; D004549:Elastin / Q000737:chemistry*; D011211:Electric Power Supplies; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010100:Oxygen / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry
chemical_list: D008670:Metals; D037742:Nanotubes, Carbon; D011993:Recombinant Fusion Proteins; D013431:Sulfates; D004549:Elastin; D008094:Lithium; D010100:Oxygen