Hollow Ni/Co‐MOFs with Controllable Surface Structure as Electrode Materials for High Performance Supercapacitors

Abstract

The metal‐organic frameworks (MOFs) with redox active metal ions and diverse organic linkers have been broadly investigated as the expecting electrode materials for supercapacitors. Here, the hollow Ni/Co‐MOFs with uniform and small protrusions can be obtained by a simple one‐pot solvothermal process, controlling the size of the protrusions on the MOFs surface by regulating the molar ratio between metal ions and trimesic acid linkers. The small protrusions can supply plenty of redox sites for the electrochemical reactions while the hollow spheres should offer sufficient contact area for the electrolyte to reduce the ion transport resistance. The prepared Ni/Co‐MOFs exhibit promising performance in the supercapacitors. The Ni/Co‐MOF with ratio of 1:1 (metal ions:trimesic acid linkers) gives outstanding performance that the specific capacity can reach 828 C g−1 when the current density is 1 A g−1 and the rate capability can reach 68% at 20 A g−1. This work may cast light on tuning the structure of MOFs to boost electrochemical capacity.

Coronavirus-Like Core–Shell-Structured Co@C for Hydrogen Evolution via Hydrolysis of Sodium Borohydride

“…Interestingly, some discrete bumps are seen on the surface of these spheres, rendering the Co@C−650 like a coronavirus. Such a coronavirus-like morphology is rarely reported in the literature [ 31 , 32 , 33 , 34 ]. As illustrated by the magnified image, these bumps are in a size range of 40–90 nm.…”

Recent Advances in Hierarchical Porous Engineering of MOFs and Their Derived Materials for Catalytic and Battery: Methods and Application

“…Zhang et al prepared hollow Ni/Co MOFs by regulating the molar ratio between organic ligand and metal ions. [84] Suh's group synthesized a series of hollow tubular MOFs ([Zn 2 (C n TPDC) 2 (bpy)] (n = 1-8; SNU-81-SNU-88, respectively) based on a synergetic effect of the longer dicarboxyl ligand incorporating alkoxy pendant groups and a controlled solubility of the ligands. [85] Li et al prepared the Zn-BTC hollow polyhedron structures with some mesoporous features by introducing gaseous CO 2 into the ionic liquid under stirring.…”

Synergistic effect of bimetallic NiCo-MOF on foamed nickel for application in high-performance supercapacitors

“…[5][6][7][8] Therefore, the development of energy conversion devices with efficient energy storage functions is of high interest to researchers. 9,10 Energy storage devices fall into three main categories: batteries, capacitors, and supercapacitors. A supercapacitor is a kind of energy storage device between the battery and capacitor, which has the advantages of fast charging and discharging ability, excellent power density, long cycle life, and high safety factor.…”

“…5–8 Therefore, the development of energy conversion devices with efficient energy storage functions is of high interest to researchers. 9,10…”