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Title: A High‐Rate Li–CO 2 Battery Enabled by 2D Medium‐Entropy Catalyst

Lithium‐air batteries based on CO2reactant (Li–CO2) have recently been of interest because it has been found that reversible Li/CO2electrochemistry is feasible. In this study, a new medium‐entropy cathode catalyst, (NbTa)0.5BiS3, that enables the reversible electrochemistry to operate at high rates is presented. This medium entropy cathode catalyst is combined with an ionic liquid‐based electrolyte blend to give a Li–CO2battery that operates at high current density of 5000 mA g−1and capacity of 5000 mAh g−1for up to 125 cycles, far exceeding reported values in the literature for this type of battery. The higher rate performance is believed to be due to the greater stability of the multi‐element (NbTa)0.5BiS3catalyst because of its higher entropy compared to previously used catalysts with a smaller number of elements with lower entropies. Evidence for this comes from computational studies giving very low surface energies (high surface stability) for (NbTa)0.5BiS3and transmission electron microscopystudies showing the structure being retained after cycling. In addition, the calculations indicate that Nb‐terminated surface promotes Li–CO2electrochemistry resulting in Li2CO3and carbon formation, consistent with the products found in the cell. These results open new direction to design and develop high‐performance Li–CO2batteries.

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Author(s) / Creator(s):
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Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Advanced Functional Materials
Medium: X
Sponsoring Org:
National Science Foundation
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