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Mechanistic Insights into the Interplay between Ion Intercalation and Water Electrolysis in Aqueous Batteries
journal contribution
posted on 2022-03-02, 13:39 authored by Yuxin Zhang, Chunguang Kuai, Anyang Hu, Lu Ma, Sha Tan, Inhui Hwang, Linqin Mu, Muhammad Mominur Rahman, Cheng-Jun Sun, Luxi Li, Enyuan Hu, Feng LinImproving electrolyte stability to
suppress water electrolysis
represents a basic principle for designing aqueous batteries. Herein,
we investigate counterintuitive roles that water electrolysis plays
in regulating intercalation chemistry. Using the NaxFe[Fe(CN)6]∥NaTi2(PO4)3 (x < 1) aqueous battery as a platform,
we report that high-voltage overcharging can serve as an electrochemical
activation approach to achieving concurrent Na-ion intercalation and
an electrolytic oxygen evolution reaction. When the cell capacity
is intrinsically limited by deficient cyclable Na ions, the electrolytic
water oxidation on the cathode allows for extra Na-ion intercalation
from the electrolyte to the NaTi2(PO4)3 anode, leading to a major increase in cyclable Na ions and specific
capacity. The parasitic oxygen generation and potential transition-metal
dissolution, as proved by our synchrotron and imaging tools, can be
significantly mitigated with a simple reassembling approach, which
enables stable electrochemical performance and sheds light on manipulating
ion intercalation and water electrolysis for battery fast charging
and recycling.
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simple reassembling approachparasitic oxygen generationinvestigate counterintuitive roleselectrochemical activation approachregulating intercalation chemistryelectrolytic water oxidationdesigning aqueous batteriesbattery fast chargingcyclable na ionsachieving concurrent nawater electrolysis playsmanipulating ion intercalation3 subwater electrolysision intercalationaqueous batteryx extra navoltage overchargingspecific capacitysignificantly mitigatedsheds lightpotential transitionmetal dissolutionmechanistic insightsmajor increaseintrinsically limitedimaging toolscell capacitycathode allowsbasic principle>< sub