Achieving High‐Performance Supercapacitors by Constructing Porous Zinc–Manganese Oxide Microstructures

Abstract

Porous zinc-manganese oxide (ZnMn 2 O 4 )m icrostructures are prepared by calcination using ap recursorm ethod, and the material is successfully applied as the supercapacitor electroactive materials in at hree-electrode cell. Due to the uniquem icro/nanostructure,t he as-prepared sample obtained under the calcinationc onditiono f4 50 8Cf or 6h achieved ah igh specific capacitance of 1093 Fg À1.T he electrode also exhibited high cycle stability for 5000 cycles.In recent years,porousm aterials have been widelya pplied in many industrial fields such as separation, [1a] adsorption, [1b] and catalysis, [1c] mainly due to their defined pore structure and size distribution. Usually porous materials are synthesized by using templating methods with soft or hard templates such as surfactants or silica, respectively.H owever, these methods require multiple complicateds teps such as removal of the templateo rs elective etching in an appropriate solvent, which would make the product impure and limit the extent of applications.Electrochemical capacitors (supercapacitors,S Cs) are one of the most important groups of electrochemical storage devices,w ith ah igher powerd ensity and much longer shelf/ cycle life than batteries;t hus,t hey are finding applications in variousp ower and energy related fields,s uch as hybrid vehicles,p ortable computers,n anoelectronics,b urst power generation, and memory back-upd evices. [2,3] Tr ansition metal oxides are one important group of pseudocapacitive electrode materials and can provide higher energy density in comparison to the electrical double layer capacitive materials such as carbon-based active materials.R ecently,b inary metal oxides have been reportedt od emonstrate better performance than single-component oxides due to their feasible oxidations tates and high electrical conductivity. [4][5][6][7][8] Tr ansition metal-oxalate-based micro/nanomaterials have recently been explored as precursors for the synthesiso fp oroust ransition metal oxides (Mn 2 O 3 , [9] NiO, [9,10] CeO 2 , [11] etc.) and porous mixed transition metal oxides (NiMn 2 O 4 , [12] Ni 0.3 Co 2.7 O 4 , [13,14] ZnO-NiO, [15] etc.). Zinc-manganese oxide (ZnMn 2 O 4 )h as raised much attention because of its wide application in the fields of catalysts,s olid electrolytes,n egative temperature coefficient thermistors,a nd sensor materials.I n ZnMn 2 O 4 ,t he bivalent Zn 2 + ions occupyt he tetrahedral sites and the trivalent Mn 3 + ions the octahedral sites in the spinel structure,a nd it has been proposed as am ore intriguing alternative anode material for advanced lithium-ion batteries (LIBs), benefiting from the low oxidationp otentials (i.e., delithiation potential) of zinc and manganesea t1 .2 and 1.5 V( vs.L i + /Li), respectively. [16][17][18][19][20][21] However, there are very few reports of the micro/nanostructured ZnMn 2 O 4 for SC applications.[22]Herein, we have successfully synthesized porous ZnMn 2 O 4 microstructures by calcinationo fa no xalate precursor under different temperatures.W eh ave not us...

Synthesis of ZnMn2O4 Nanoparticles by a Microwave-Assisted Colloidal Method and their Evaluation as a Gas Sensor of Propane and Carbon Monoxide

“…ZnMn 2 O 4 is an interesting compound that has been widely used as an electrode for Li-ion batteries due to its low cost and being environmentally friendly [19,20,21,22,23,24]. Also, this material has been used as a supercapacitor [25,26,27,28,29] and thermistor [30] due to its structural, physical, and chemical properties. It has been reported that zinc manganite shows strong catalytic activity [31,32,33,34,35]; therefore, this material could perform well as a gas sensor.…”

Crumpled ZnMn2O4 Nanosheets for Long‐Term‐Cycling Lithium‐Ion Battery Anodes

“…Usually, ternary transition metal oxides have shown better performance than single metal oxides due to their possible synergetic enhancement . Hence, nanostructured ZnMn 2 O 4 has been investigated to improve the electrochemical performance for LIBs …”

“…[10] Hence,n anostructured ZnMn 2 O 4 has been investigatedtoimprovet he electrochemical performancefor LIBs. [10][11][12][13][14][15][16][17][18][19][20][21][22] Nanosheets and nanofibers are important in various applications such as optoelectronics, [23] solar cells, [24] and LIBs, [25] because of their high specific surface areas and short transport paths for electrons and ions.I np articular, such nanostructured materials have been extensivelys tudied as alternative LIB electrodes,with long-term cycling and ahighly reversible electrode reaction as ar esult of their ability to buffer the mechanical stress more effectively during repeated cycling.T os ynthesize the nanostructure,v ariousm ethods have been explored, mostly including hydrothermal or template routes. [26,27] However, these methods are often involved with complexp rocesses.E lectrospinning is as imple and effective methodf or fabricating nanostructures,a nd this methoda long with particular thermal treatment could be used to achieve many interestingm ultilevel nanostructures (branched nanowires, [24] wire-in-tube, [28] bamboo joint [29] ).…”

Ultra-tiny ZnMn2O4 nanoparticles encapsulated in sandwich-like carbon nanosheets for high-performance supercapacitors

“…Compared to the other designs [21,57], it is significant to put forward the idea of novel sandwich-like ZnMn 2 O 4 nanoparticles encapsulated in carbon nanosheets (sandwichlike ZnMn 2 O 4 /C). In this study, the massive sandwiched ZnMn 2 O 4 /C was prepared through a simple hydrothermal and sacrificial template method.…”