High-Entropy Metal-Organic Frameworks for Highly Reversible Sodium Storage

被引：269

作者：

Ma, Yanjiao ^{[1
]}

Ma, Yuan ^{[1
]}

Dreyer, Soeren Lukas ^{[1
]}

Wang, Qingsong ^{[1
]}

Wang, Kai ^{[1
]}

Goonetilleke, Damian ^{[1
]}

Omar, Ahmad ^{[2
]}

Mikhailova, Daria ^{[2
]}

Hahn, Horst ^{[1
,3
,4
,5
]}

Breitung, Ben ^{[1
]}

Brezesinski, Torsten ^{[1
]}

机构：

[1] Karlsruhe Inst Technol KIT, Inst Nanotechnol, Hermann von Helmholtz Pl 1, D-76344 Eggenstein Leopoldshafen, Germany

[2] Leibniz Inst Solid State & Mat Res IFW Dresden, Helmholtzstr 20, D-01069 Dresden, Germany

[3] Tech Univ Darmstadt, Joint Res Lab Nanomat, Otto Berndt Str 3, D-64206 Darmstadt, Germany

[4] Karlsruhe Inst Technol KIT, Otto Berndt Str 3, D-64206 Darmstadt, Germany

[5] Helmholtz Inst Ulm HIU Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany

来源：

ADVANCED MATERIALS | 2021年 / 33卷 / 34期

关键词：

gassing behavior; high-entropy materials; Prussian blue analogues; secondary batteries; sodium-ion cathodes; PRUSSIAN BLUE ANALOGS; ELECTROCHEMICAL PROPERTIES; CATHODE MATERIALS; ANODE MATERIAL; ION; PERFORMANCE; NICKEL; HEXACYANOFERRATE; TRANSITION; POTASSIUM;

D O I：

10.1002/adma.202101342

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Prussian blue analogues (PBAs) are reported to be efficient sodium storage materials because of the unique advantages of their metal-organic framework structure. However, the issues of low specific capacity and poor reversibility, caused by phase transitions during charge/discharge cycling, have thus far limited the applicability of these materials. Herein, a new approach is presented to substantially improve the electrochemical properties of PBAs by introducing high entropy into the crystal structure. To achieve this, five different metal species are introduced, sharing the same nitrogen-coordinated site, thereby increasing the configurational entropy of the system beyond 1.5R. By careful selection of the elements, high-entropy PBA (HE-PBA) presents a quasi-zero-strain reaction mechanism, resulting in increased cycling stability and rate capability. The key to such improvement lies in the high entropy and associated effects as well as the presence of several active redox centers. The gassing behavior of PBAs is also reported. Evolution of dimeric cyanogen due to oxidation of the cyanide ligands is detected, which can be attributed to the structural degradation of HE-PBA during battery operation. By optimizing the electrochemical window, a Coulombic efficiency of nearly 100% is retained after cycling for more than 3000 cycles.

引用

页数：10