Open AccessFree‐Standing α‐MoO 3 / Ti 3 C 2 MXene Hybrid Electrode in Water‐in‐Salt Electrolytes
Author(s) -
Saraf Mohit,
Shuck Christopher E.,
Norouzi Nazgol,
Matthews Kyle,
Inman Alex,
Zhang Teng,
Pomerantseva Ekaterina,
Gogotsi Yury
Publication year - 2023
Publication title -
energy and environmental materials
Language(s) - Uncategorized
Resource type - Journals
ISSN - 2575-0356
DOI - 10.1002/eem2.12516
Subject(s) - mxenes , electrolyte , electrochemistry , electrochemical window , materials science , conductivity , electrode , chemical engineering , dissolution , aqueous solution , inorganic chemistry , lithium (medication) , ionic conductivity , chemistry , nanotechnology , medicine , endocrinology , engineering
While transition‐metal oxides such as α‐MoO 3 provide high capacity, their use is limited by modest electronic conductivity and electrochemical instability in aqueous electrolytes. Two‐dimensional (2D) MXenes, offer metallic conductivity, but their capacitance is limited in aqueous electrolytes. Insertion of partially solvated cations into Ti 3 C 2 MXene from lithium‐based water‐in‐salt (WIS) electrolytes enables charge storage at positive potentials, allowing a wider potential window and higher capacitance. Herein, we demonstrate that α‐MoO 3 /Ti 3 C 2 hybrids combine the high capacity of α‐MoO 3 and conductivity of Ti 3 C 2 in WIS (19.8 m LiCl) electrolyte in a wide 1.8 V voltage window. Cyclic voltammograms reveal multiple redox peaks from α‐MoO 3 in addition to the well‐separated peaks of Ti 3 C 2 in the hybrid electrode. This leads to a higher specific charge and a higher rate capability compared to a carbon and binder containing α‐MoO 3 electrode. These results demonstrate that the addition of MXene to less conductive oxides eliminates the need for conductive carbon additives and binders, leads to a larger amount of charge stored, and increases redox capacity at higher rates. In addition, MXene encapsulated α‐MoO 3 showed improved electrochemical stability, which was attributed to the suppressed dissolution of α‐MoO 3 . The work suggests that oxide/MXene hybrids are promising for energy storage.