Aprotic Li-O2 batteries have attracted a huge amount of interest in the past decade owing to their extremely high energy density. However, identifying a desirable cathodic catalyst for this promising battery system is one of the biggest challenges at present. In this work, a multi-layered Fe2O3/graphene nanosheets (Fe2O3/GNS) composite with sandwich structure was synthesized using an easy thermal casting method, and served as a cathodic catalyst for aprotic Li-O2 batteries. The aprotic Li-O2 cell with the Fe2O3/GNS catalyst demonstrated a better reversibility, lower overpotential for oxygen evolution, and a higher Coulombic efficiency (close to 100%) than those of pure GNS. An excellent rate performance and good cycle stability were also confirmed. The results, characterized by ex and in situ methods, revealed that the dominant discharge product Li2O2 was decomposed below 4.35 V. This superior electrochemical performance is mainly attributed to the unique sandwich structure of the Fe2O3/GNS catalyst with mesopores, which can provide substantially more catalytic sites and prevent direct contact between carbon and Li2O2.
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http://dx.doi.org/10.1088/0957-4484/27/36/365402 | DOI Listing |
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July 2024
Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, 066004, P. R. China.
Rechargeable aprotic lithium (Li)-oxygen battery (LOB) is a potential next-generation energy storage technology because of its high theoretical specific energy. However, the role of redox mediator on the oxide electrochemistry remains unclear. This is partly due to the intrinsic complexity of the battery chemistry and the lack of in-depth studies of oxygen electrodes at the atomic level by reliable techniques.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2023
Research and Innovation Center on CO2 and Hydrogen (RICH Center) and Chemical Engineering Department, Khalifa University, P.O. Box 127788, Abu Dhabi 127788, United Arab Emirates.
The commercialization of ultrahigh capacity lithium-oxygen (Li-O) batteries is highly dependent on the cathode architecture, and a better understanding of its role in species transport and solid discharge product (i.e., LiO) formation is critical to improving the discharge capacity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
March 2023
State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China.
LiI and LiBr have been employed as soluble redox mediators (RMs) in electrolytes to address the sluggish oxygen evolution reaction kinetics during charging in aprotic Li-O batteries. Compared to LiBr, LiI exhibits a redox potential closer to the theoretical one of discharge products, indicating a higher energy efficiency. However, the reason for the occurrence of solvent deprotonation in LiI-added electrolytes remains unclear.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2022
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin, 300071, China.
Aprotic Li-O batteries are a promising energy storage technology, however severe side reactions during cycles lead to their poor rechargeability. Herein, highly reactive singlet oxygen (O) is revealed to generate in both the discharging and charging processes and is deterimental to battery stability. Electron-rich triphenylamine (TPA) is demonstrated as an effective quencher in the electrolyte to mitigate O and its associated parasitic reactions, which has the tertiary amine and phenyl groups to manifest excellent electrochemical stability and chemical reversibility.
View Article and Find Full Text PDFNanomaterials (Basel)
July 2022
Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, China.
LiO, as the cathodic discharge product of aprotic Li-O batteries, is difficult to electrochemically decompose. Transition-metal oxides (TMOs) have been proven to play a critical role in promoting the formation and decomposition of LiO. Herein, a NiO/CNT catalyst was prepared by anchoring a NiO nanosheet on the surface of CNT.
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