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Atomic Engineering Catalyzed MnO 2 Electrolysis Kinetics for a Hybrid Aqueous Battery with High Power and Energy Density
Author(s) -
Chao Dongliang,
Ye Chao,
Xie Fangxi,
Zhou Wanhai,
Zhang Qinghua,
Gu Qinfen,
Davey Kenneth,
Gu Lin,
Qiao ShiZhang
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202001894
Subject(s) - materials science , electrolysis , battery (electricity) , aqueous solution , electrochemistry , electrolyte , energy storage , density functional theory , chemical engineering , electrode , chemistry , thermodynamics , computational chemistry , power (physics) , physics , engineering
Research interest and achievements in zinc aqueous batteries, such as alkaline Zn//Mn, Zn//Ni/Co, Zn–air batteries, and near‐neutral Zn‐ion and hybrid ion batteries, have surged throughout the world due to their features of low‐cost and high‐safety. However, practical application of Zn‐based secondary batteries is plagued by restrictive energy and power densities in which an inadequate output plateau voltage and sluggish kinetics are mutually accountable. Here, a novel paradigm high‐rate and high‐voltage Zn–Mn hybrid aqueous battery (HAB) is constructed with an expanded electrochemical stability window over 3.4 V that is affordable. As a proof of concept, catalyzed MnO 2 /Mn 2+ electrolysis kinetics is demonstrated in the HAB via facile introduction of Ni 2+ into the electrolyte. Various techniques are employed, including in situ synchrotron X‐ray powder diffraction, ex situ X‐ray absorption fine structure, and electron energy loss spectroscopy, to reveal the reversible charge‐storage mechanism and the origin of the boosted rate‐capability. Density functional theory (DFT) calculations reveal enhanced active electron states and charge delocalization after introducing strongly electronegative Ni. Simulations of the reaction pathways confirm the enhanced catalyzed electrolysis kinetics by the facilitated charge transfer at the active O sites around Ni dopants. These findings significantly advance aqueous batteries a step closer toward practical low‐cost application.