Effect of the Anionic Counterpart: Molybdate vs. Tungstate in Energy Storage for Pseudo-Capacitor Applications

Nickel-based bimetallic oxides (BMOs) have shown significant potential in battery-type electrodes for pseudo-capacitors given their ability to facilitate redox reactions. In this work, two bimetallic oxides, NiMoO<sub>4</sub> and NiWO<sub>4</sub>, were synthesized using a wet...

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Bibliographic Details
Main Authors: Pratigya Sharma, Manickam Minakshi, Jonathan Whale, Annelise Jean-Fulcrand, Georg Garnweitner
Format: Article
Language:English
Published: MDPI AG 2021-02-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/11/3/580
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Summary:Nickel-based bimetallic oxides (BMOs) have shown significant potential in battery-type electrodes for pseudo-capacitors given their ability to facilitate redox reactions. In this work, two bimetallic oxides, NiMoO<sub>4</sub> and NiWO<sub>4</sub>, were synthesized using a wet chemical route. The structure and electrochemical properties of the pseudo-capacitor cathode materials were characterized. NiMoO<sub>4</sub> showed superior charge storage performance in comparison to NiWO<sub>4</sub>, exhibiting a discharge capacitance of 124 and 77 F·g<sup>−1</sup>, respectively. NiMoO<sub>4</sub>, moreover, demonstrates better capacity retention after 1000 cycles with 87.14% compared to 82.22% for NiWO<sub>4</sub>. The lower electrochemical performance of the latter was identified to result from the redox behavior during cycling. NiWO<sub>4</sub> reacts in the alkaline solution and forms a passivation layer composed of WO<sub>3</sub> on the electrode, while in contrast, the redox behavior of NiMoO<sub>4</sub> is fully reversible.
ISSN:2079-4991