Stabilizing the oxygen lattice and reversible oxygen redox in Na-deficient cathode oxides

Zheng，Wei1; Liu，Qiong1,2,3; Wang，Zhenyu1; Yi，Zhibin1; Li，Yingzhi1; Cao，Lujie1; Zhang，Kaili2,3; Lu，Zhouguang1

2019-11-01

10.1016/j.jpowsour.2019.227086

JOURNAL OF POWER SOURCES   影响因子和分区

0378-7753

1873-2755

To overcome the limitation of capacity from traditional oxide-based intercalation cathodes, oxygen redox reaction garners intense interest in Li-rich/Na-rich cathodes for rechargeable batteries. However, cycle degradation and voltage drop caused by the irreversible structural changes and O release upon electrochemical cycling hinder their commercial applications. Herein, a Na-deficient layered compound NaMnZnO is employed to study the relationship between the oxygen redox reaction and the (O) stabilization mechanism by using a combined experimental and computational approach. Our results indicate that NaMnZnO has a long plateau of approximately 4.1 V with a total capacity of 157 mAh g, majorly stemming from the oxygen redox reactions of O/(O). The O-2p nonbonding states originating from the weak Zn–O interaction and the shortened O–O bonds induced by the absence of Na atoms in the alkali layers catalyze the formation of peroxo-like O–O dimer between the Mn–Mn atoms. The honeycomb TM layer of the Na-deficient materials remains stable with a small O–O bond length evolution from 2.55 Å to 2.48 Å during the oxygen redox process, which stabilizes the lattice oxygen in electrochemical cycles. This finding is important for further understanding the mechanism underlying the oxygen redox chemistry of high energy Na-deficient cathode materials.

Cathode material Lattice oxygen stabilization Oxygen redox reaction O–O shortening Sodium ion battery

SCI ; EI

英语

第一 ; 通讯

National Natural Science Foundation of China[21875097] ; National Natural Science Foundation of China[21671096]

Chemistry ; Electrochemistry ; Energy & Fuels ; Materials Science

Chemistry, Physical ; Electrochemistry ; Energy & Fuels ; Materials Science, Multidisciplinary

WOS:000494891700003

ELSEVIER

20193607405075

Bond length ; Cathodes ; Dimers ; Manganese compounds ; Metal ions ; Oxygen ; Redox reactions ; Sodium-ion batteries ; Stabilization ; Zinc compounds

Metallurgy:531.1 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Chemical Products Generally:804 ; Organic Polymers:815.1.1

MATERIALS SCIENCE

2-s2.0-85071695606

Scopus

1.Department of Materials Science and EngineeringSouthern University of Science and Technology,Shenzhen,518055,China
2.Department of Mechanical EngineeringCity University of Hong Kong,83 Tat Chee Avenue,999077,Hong Kong
3.Shenzhen Research InstituteCity University of Hong Kong,Shenzhen,518057,China

Zheng，Wei,Liu，Qiong,Wang，Zhenyu,et al. Stabilizing the oxygen lattice and reversible oxygen redox in Na-deficient cathode oxides[J]. JOURNAL OF POWER SOURCES,2019,439.

Zheng，Wei.,Liu，Qiong.,Wang，Zhenyu.,Yi，Zhibin.,Li，Yingzhi.,...&Lu，Zhouguang.(2019).Stabilizing the oxygen lattice and reversible oxygen redox in Na-deficient cathode oxides.JOURNAL OF POWER SOURCES,439.

Zheng，Wei,et al."Stabilizing the oxygen lattice and reversible oxygen redox in Na-deficient cathode oxides".JOURNAL OF POWER SOURCES 439(2019).