am1c19684_si_003.pdf (1.65 MB)
Mechanistic Insights into the Interplay between Ion Intercalation and Water Electrolysis in Aqueous Batteries
journal contributionposted 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 Lin
Improving 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.
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