Self-templated pseudomorphic transformation of ZIF into layered double hydroxides for improved supercapacitive performance

Leiping Liao; Kun Zheng; Yu Zhang; Xiuzhen Li; Degang Jiang; Jingquan Liu

doi:10.1016/j.jcis.2022.04.088

Self-templated pseudomorphic transformation of ZIF into layered double hydroxides for improved supercapacitive performance

J Colloid Interface Sci. 2022 Sep 15:622:309-318. doi: 10.1016/j.jcis.2022.04.088. Epub 2022 Apr 20.

Authors

Leiping Liao¹, Kun Zheng², Yu Zhang², Xiuzhen Li², Degang Jiang³, Jingquan Liu⁴

Affiliations

¹ College of Materials Science and Engineering, Linyi University, Linyi, Shandong 276000, China; College of Materials Science and Engineering, Institute for Graphene Applied Technology Innovation, Qingdao University, Ningxia Road 308 Qingdao 266071, China.
² College of Materials Science and Engineering, Institute for Graphene Applied Technology Innovation, Qingdao University, Ningxia Road 308 Qingdao 266071, China.
³ Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia. Electronic address: djiang@deakin.edu.au.
⁴ College of Materials Science and Engineering, Linyi University, Linyi, Shandong 276000, China; College of Materials Science and Engineering, Institute for Graphene Applied Technology Innovation, Qingdao University, Ningxia Road 308 Qingdao 266071, China. Electronic address: jliu@qdu.edu.cn.

PMID: 35512594
DOI: 10.1016/j.jcis.2022.04.088

Abstract

Zeolitic imidazole frameworks (ZIFs) have been researched as excellent templates for synthesizing functional materials to be used in various fields. However, direct adoption of ZIFs as electrode material shows dissatisfactory electrochemical performance due to their limited exposed electroactive sites, poor chemical stability and sluggish charging dynamics. Herein, we demonstrate in situ transformation of ZnCo-ZIF frameworks decorated on ZnCo nanorod array (ZnCo-NA) into three-dimensional (3D) spatially distributed ZnCo-LDH/ZnCo-NA heterostructure. Owing to this unique structure that can provide abundant electroactive sites and ion transport paths in all directions, the resulting ZnCo-LDH/ZnCo-NA electrode exhibits an improved supercapacitive performance with a high capacity of 15.76 F cm^-2 (1576 F g^-1, 788 C g^-1) at 20 mA cm^-2 (2 A g^-1), and maintains the capacity of 13.855 F cm^-2 (1385.5 F g^-1, 692.75 C g^-1) at 150 mA cm^-2 (15 A g^-1), showing a high rate capability of 87.9%. A coin cell asymmetric supercapacitor (aSC) is assembled by employing ZnCo-LDH/ZnCo-NA as cathode and active carbon as anode, which exhibits an energy density of 21.3 Wh kg^-1 and superb cycling performance with capacitance retention of 88.1% after 5000 cycles. More importantly, such a simple in-situ pseudomorphic transformation of ZIF templates into novel class LDH materials demonstrates a new generation of bimetallic heterostructure for applications in energy-related fields and beyond.

Keywords: 3D spatial structure; Layered double hydroxides; Supercapacitor; Zeolitic imidazole frameworks.