Synthesis of Cobalt Sulfide Multi‐shelled Nanoboxes with Precisely Controlled Two to Five Shells for Sodium‐Ion Batteries

Abstract

We report the synthesis of cobalt sulfide multishelled nanoboxes through metal-organic framework (MOF)based complex anion conversion and exchange processes.The polyvanadate ions react with cobalt-based zeolitic imidazolate framework-67 (ZIF-67) nanocubes to form ZIF-67/cobalt polyvanadate yolk-shelled particles.T he as-formed yolkshelled particles are gradually converted into cobalt divanadate multi-shelled nanoboxes by solvothermal treatment. The number of shells can be easily controlled from 2t o5by varying the temperature.F inally,c obalt sulfide multi-shelled nanoboxes are produced through ion-exchange with S 2À ions and subsequent annealing. The as-obtained cobalt sulfide multi-shelled nanoboxes exhibit enhanced sodium-storage properties when evaluated as anodes for sodium-ion batteries. Fore xample,ahigh specific capacity of 438 mAh g À1 can be retained after 100 cycles at the current density of 500 mA g À1 .The fast depletion of fossil fuels and growing environmental concerns have prompted intense research efforts for the development of clean and sustainable energy storage and conversion technologies.Electrical energy storage devices as one of the most important components in the development of sustainable energy systems have attracted significant research interest. [1][2][3] Besides lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) have been considered as one promising energy storage alternative because sodium is abundantly available. [2,[4][5][6][7][8] Among the potential negative electrode materials for SIBs,t ransition metal sulfides (TMSs) are quite attractive because of their rich redox sites,high capacity and enhanced electrical conductivity compared with their oxide counterparts. [9][10][11][12][13] However,p ractical applications of TMSs are still hindered by the poor rate performance and fast capacity fading due to the low intrinsic electric conductivity, gradually reduced crystallinity and inevitable volume changes during prolonged cycling.To circumvent these problems,r ational design of the structural complexity of active materials has been proved ap romising strategy. [9,[14][15][16][17][18] In particular,h ollow structures with complex interiors have drawn significant attention owing to their structure-dependent merits.A sf or sodium storage applications,i ntricate hollow structures exhibit great advantages over simple hollow architectures. [16,[19][20][21] Complex hollow particles not only inherit all the advantages of hollow structures,i ncluding high surface area, enhanced volume change accommodation and large electrode/electrolyte interface,b ut also improve the weight fraction of active species,thus dramatically enhancing the energy density of the electrode materials. [22] As ar esult, av ariety of electrode materials have been fabricated in the form of multi-shelled hollow structures. [23][24][25][26][27][28][29][30][31] It is also noted that non-spherical particles might exhibit some advantage for SIBs, [9,15] owing to their larger surface area compared to spherical counterpart...

Heat Diffusion‐Induced Gradient Energy Level in Multishell Bisulfides for Highly Efficient Photocatalytic Hydrogen Production

“…[ 5,6,17 ] Among them, precisely designed hollow multishell structures possess attractive characteristics for photocatalysis, including efficient light harvesting, improved charge transfer, and high specific surface area. [ 17,21,27–32 ] Single/multishell hollow spheres, [ 18,33,34 ] hollow cubes, [ 35–37 ] egg yolk shells, [ 27,36,38 ] and other shaped hollow spheres have been reported. [ 19,28,39–41 ] In general, the preparation and synthesis of multishell structured photocatalysts can be divided into three methods according to the template used: hard templating, soft templating, and self‐templating method.…”

Synthesis of Copper‐Substituted CoS2@CuxS Double‐Shelled Nanoboxes by Sequential Ion Exchange for Efficient Sodium Storage

“…In huge contrast, the capacity of CoS 2 SSNBs faded dramatically. The rate capability and cycling stability of Cu‐CoS 2 @Cu x S DSNBs were also superior to those of most reported Co x S‐based electrodes . Moreover, the nanobox structure of the Cu‐CoS 2 @Cu x S DSNBs was still well‐preserved after prolonged cycling (see Figure S16).…”

Hollow Structured Metal Sulfides for Photocatalytic Hydrogen Generation

“…Schematic illustration of the formation process of cobalt sulfide MSNB is shown in Figure (c). Notably, the number of shells were controlled by adjusting the solvothermal process temperature and the initial particle size of ZIF‐67 nanocubes precursors . Similarly, multi‐shelled ZnS−CdS rhombic dodecahedral hollow nanostructures with tunable compositions and shell numbers were fabricated by Zhang et al.…”