Zhang Yuxin, Kuai Chunguang, Hu Anyang, Ma Lu, Tan Sha, Hwang Inhui, Mu Linqin, Rahman Muhammad Mominur, Sun Cheng-Jun, Li Luxi, Hu Enyuan, Lin Feng
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24073, United States.
National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States.
ACS Appl Mater Interfaces. 2022 Mar 16;14(10):12130-12139. doi: 10.1021/acsami.1c19684. Epub 2022 Mar 1.
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 NaFe[Fe(CN)]∥NaTi(PO) ( < 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 NaTi(PO) 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.
提高电解质稳定性以抑制水电解是设计水系电池的基本原则。在此，我们研究了水电解在调节嵌入化学过程中所起的反直觉作用。以NaFe[Fe(CN)]∥NaTi(PO)（<1）水系电池为平台，我们报道了高压过充电可作为一种电化学活化方法，实现同时进行钠离子嵌入和电解析氧反应。当电池容量因可循环钠离子不足而本质上受到限制时，阴极上的电解水氧化允许额外的钠离子从电解质嵌入到NaTi(PO)阳极，导致可循环钠离子和比容量大幅增加。通过我们的同步加速器和成像工具证明，采用简单的重新组装方法可显著减轻寄生氧生成和潜在的过渡金属溶解，这使得电化学性能稳定，并为电池快速充电和回收中操纵离子嵌入和水电解提供了思路。
