When aprotic Li-O2 batteries discharge, the product phase formed in the cathode often contains two different morphologies, that is, crystalline and amorphous Li2 O2 . The morphology of Li2 O2 impacts strongly on the electrochemical performance of Li-O2 cells in terms of energy efficiency and rate capability. Crystalline Li2 O2 is readily available and its properties have been studied in depth for Li-O2 batteries. However, little is known about the amorphous Li2 O2 because of its rarity in high purity. Herein, amorphous Li2 O2 has been synthesized by a rapid reaction of tetramethylammonium superoxide and LiClO4 in solution, and its amorphous nature has been confirmed by a range of techniques. Compared with its crystalline siblings, amorphous Li2 O2 demonstrates enhanced charge-transport properties and increased electro-oxidation kinetics, manifesting itself a desirable discharge phase for high-performance Li-O2 batteries.
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http://dx.doi.org/10.1002/anie.201605228 | DOI Listing |
Nano Lett
November 2023
Tianmu Lake Institute of Advanced Energy Storage Technologies, Liyang, Jiangsu 213300, China.
The Li superionic conductor LiBS has been theoretically predicted as an ideal solid electrolyte (SE) due to its low Li migration energy barrier and high ionic conductivity. However, the experimentally synthesized LiBS has a 10 times lower ionic conductivity. Herein, we investigate the effect of a series of cation and anion substitutions in LiBS SE on its ionic conductivity, including LiMBS (M = Cu, Zn, Sn, P, W, = 0.
View Article and Find Full Text PDFAdv Sci (Weinh)
November 2023
Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
Investigations into lithium-sulfur batteries (LSBs) has focused primarily on the initial conversion of lithium polysulfides (LiPSs) to Li S . However, the subsequent solid-solid reaction from Li S to Li S and the Li S decomposition process should be equally prioritized. Creating a virtuous cycle by balancing all three chemical reaction processes is crucial for realizing practical LSBs.
View Article and Find Full Text PDFSmall
December 2023
Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Heterogeneous crystalline-amorphous structures, with tunable electronic structures and morphology, hold immense promise as catalysts for lithium-oxygen batteries (LOBs). Herein, a nanotube network constructed by crystalline nickel sulfide/amorphous nickel phosphate (NiS/NiPO) heterostructure is prepared on Ni foam through the sulfurization of the precursor generated hydrothermally. Used as cathodes, the NiS/NiPO nanotubes with optimized electronic structure can induce the deposition of the highly porous and interconnected structure of Li O with rich Li O -electrolyte interfaces.
View Article and Find Full Text PDFAdv Mater
July 2023
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea.
Since the recognition of a significant oxygen-redox contribution to enhancing the capacity of Li transition-metal oxide cathodes, the oxygen release and subsequent structural variations together with capacity fading are critical issues to achieve better electrochemical performance. As most previous reports dealt with the structural degradation of cathodes after electrochemical cycling, it is fairly difficult to clarify how substantial the effect of lattice strain on the oxygen release will be while exclusively ruling out any electrochemical influences. By utilizing nanoindentation and mechanical surface polishing of single-crystal LiCoO and Li MnO , the local variations of both the atomic structure and oxygen content are scrutinized.
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September 2023
Department of Applied Chemistry, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
All-solid-state lithium-sulfur (Li/S) batteries are promising next-generation energy-storage devices owing to their high capacities and long cycle lives. The Li S active material used in the positive electrode has a high theoretical capacity; consequently, nanocomposites composed of Li S, solid electrolytes, and conductive carbon can be used to fabricate high-energy-density batteries. Moreover, the active material should be constructed with both micro- and nanoscale ion-conduction pathways to ensure high power.
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