Designing an effective microstructural cathode combined with a highly efficient catalyst is essential for improving the electrochemical performance of Li-O2 batteries (LOBs), especially for long-term cycling. We present a nickel foam-supported composite of Pt nanoparticles (NPs) coated on self-standing carbon nanotubes (CNTs) as a binder-free cathode for LOBs. The assembled LOBs can afford excellent electrochemical performance with a reversible capacity of 4050 mAh/g tested at 20 mA/g and superior cyclability for 80 cycles with a limited capacity of 1500 mAh/g achieved at a high current density of 400 mA/g. The capacity corresponds to a high energy density of ∼3000 Wh/kg. The improved performance should be attributed to the excellent catalytic activity of highly dispersed Pt NPs, facile electron transport via loose CNTs connected to the nickel foam current collector, and fast O2 diffusion through the porous Pt/CNTs networks. In addition, some new insights from impedance analysis have been proposed to explain the enhanced mechanism of LOBs.
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http://dx.doi.org/10.1021/am502411y | DOI Listing |
ACS Nano
January 2025
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan 250061, P. R. China.
To achieve a long cycle life and high-capacity performance for Li-O batteries, it is critical to rationally modulate the formation and decomposition pathway of the discharge product LiO. Herein, we designed a highly efficient catalyst containing dual catalytic active sites of Pt single atoms (Pt) paired with high-entropy alloy (HEA) nanoparticles for oxygen reduction reaction (ORR) in Li-O batteries. HEA is designed with a moderate d-band center to enhance the surface adsorbed LiO intermediate (LiO(ads)), while Pt active sites exhibit weak adsorption energy and promote the soluble LiO pathway (LiO(sol)).
View Article and Find Full Text PDFChem Rec
January 2025
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institution of New Energy, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai, 200438, China.
This paper emphasizes the critical role of electrolyte selection in enhancing the electrochemical performance of nonaqueous Li-O batteries (LOBs). It provides a comprehensive overview of various electrolyte types and their effects on the electrochemical performance for LOBs, offering insights for future electrolyte screening and design. Despite recent advancements, current electrolyte systems exhibit inadequate stability, necessitating the urgent quest for an ideal nonaqueous electrolyte.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, University of Chinese Academy of Science 457 Zhongshan Road, Dalian, 116023, China.
The addition of a redox mediator as soluble catalyst into electrolyte can effectively overcome the bottlenecks of poor energy efficiency and limited cyclability for Li-O batteries caused by passivation of insulating discharge products and unfavorable byproducts. Herein we report a novel soluble catalyst of bifunctional imidazolyl iodide salt additive, 1,3-dimethylimidazolium iodide (DMII), to successfully construct highly efficient and durable Li-O batteries. The anion I can effectively promote the charge transport of LiO and accelerate the redox kinetics of oxygen reduction/oxygen evolution reactions on the cathode side, thereby significantly decreasing the charge/discharge overpotential.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, China.
Developing highly active and durable non-noble metal catalysts is crucial for energy conversion and storage, especially for proton exchange membrane fuel cells (PEMFCs) and lithium-oxygen (Li-O) batteries. Non-noble metal catalysts are considered the greatest potential candidates to replace noble metal catalysts in PEMFCs and Li-O batteries. Herein, we propose a novel type of non-noble metal catalyst (Fe-Hf/N/C) doped with Hf into a mesoporous carbon material derived from Hf-ZIF-8 and co-doping with Fe and N, which greatly enhanced the activity and durability of the catalyst.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
College of Engineering and Applied Sciences, Center for Energy Storage Materials and Technologies, Jiangsu Key Laboratory of Artificial Functional Materials, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China.
In Li-O batteries (LOBs), the electron transfer between triplet O and singlet LiO possesses a spin-dependent character but is still neglected, while the spin-conserved electron transfer without losing phase information should guarantee fast kinetics and reduced energy barriers. Here, we provide a paradigm of spin-selective catalysis for LOB that the ferromagnetic quantum spin exchange interactions between Pt and Fe atoms in fully-exposed PtFe clusters filter directional e-spins for spin-conserved electron transfer at Fe-Fe sites. The kinetics of O/LiO redox reaction is markedly accelerated as predicted by theoretical calculations, showing dramatically decreased relaxation time of the rate determining step for more than one order of magnitude, compared with the Fe clusters without spin-selective behavior.
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