Intercalation-type catalyst for non-aqueous room temperature sodium-sulfur batteries

Autor: Jiarui He, Amruth Bhargav, Laisuo Su, Harry Charalambous, Arumugam Manthiram
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Nature Communications, Vol 14, Iss 1, Pp 1-10 (2023)
Druh dokumentu: article
ISSN: 2041-1723
DOI: 10.1038/s41467-023-42383-3
Popis: Abstract Ambient-temperature sodium-sulfur (Na-S) batteries are potential attractive alternatives to lithium-ion batteries owing to their high theoretical specific energy of 1,274 Wh kg−1 based on the mass of Na2S and abundant sulfur resources. However, their practical viability is impeded by sodium polysulfide shuttling. Here, we report an intercalation-conversion hybrid positive electrode material by coupling the intercalation-type catalyst, MoTe2, with the conversion-type active material, sulfur. In addition, MoTe2 nanosheets vertically grown on graphene flakes offer abundant active catalytic sites, further boosting the catalytic activity for sulfur redox. When used as a composite positive electrode and assembled in a coin cell with excess Na, a discharge capacity of 1,081 mA h gs −1 based on the mass of S with a capacity fade rate of 0.05% per cycle over 350 cycles at 0.1 C rate in a voltage range of 0.8 to 2.8 V is realized under a high sulfur loading of 3.5 mg cm−2 and a lean electrolyte condition with an electrolyte-to-sulfur ratio of 7 μL mg−1. A fundamental understanding of the electrocatalysis of MoTe2 is further revealed by in-situ synchrotron-based operando X-ray diffraction and ex-situ time-of-flight secondary ion mass spectrometry.
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