In:
Journal of Materials Chemistry A, Royal Society of Chemistry (RSC), Vol. 10, No. 14 ( 2022), p. 7718-7727
Abstract:
Owing to their high reactivity toward lithium, molybdenum oxides have been widely studied as anode materials for lithium-ion batteries. The two most common molybdenum oxides, MoO 2 and MoO 3 , are reported to undergo sequential insertion and conversion reactions during lithiation. Accordingly, the theoretical capacity of MoO 3 is higher than that of MoO 2 because of the higher oxidation state of Mo. However, some nanostructured MoO 2 exhibits abnormally high reversible capacity close to that of MoO 3 , which cannot be explained by the conversion reaction mechanism. Herein, the charge storage behavior of the two molybdenum oxides is comparatively analyzed. Structural investigation using synchrotron X-rays demonstrates that the conversion reaction occurs in MoO 3 , whereas MoO 2 accommodates a large amount of lithium in the form of metallic lithium. As a result, MoO 2 - and MoO 3 -based composite materials exhibit similar reversible capacities of ∼1017 and 1110 mA h g −1 , although the changes in the oxidation state of Mo during lithiation are much smaller in the MoO 2 /graphene composite. First-principles calculations demonstrate that the origin of the different electrochemical properties is the different metal–oxygen bonding properties of MoO 2 and MoO 3 . Understanding the bonding-dependent electrochemical properties in this work could provide a new perspective for designing high-performance electrode materials.
Type of Medium:
Online Resource
ISSN:
2050-7488
,
2050-7496
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
2702232-8
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