Due to its ultra-fast charge/discharge rate,long cyclic life span,and environmental benignity,aqueous supercapacitor(SC)is considered as a proper nextgeneration energy storage device.Unfortunately,limited by undesirab...Due to its ultra-fast charge/discharge rate,long cyclic life span,and environmental benignity,aqueous supercapacitor(SC)is considered as a proper nextgeneration energy storage device.Unfortunately,limited by undesirable water electrolysis and unreasonable electrode potential range,aqueous SC normally generates a narrow cell voltage,resulting in a low energy density.To address such challenge,enormous efforts have been made to construct high-voltage aqueous SCs.Despite these achievements,the systematic reviews about this field are still rare.To fill this knowledge gap,this review summarizes the recent advances about boosting the cell voltage of aqueous SCs.From the viewpoint of electrode,doping alkali cations,modulating the electrode mass ratio,and optimizing the surface charge density are regarded as three effective pathways to achieve this goal.However,adjusting the appropriate pH level,introducing redox mediators,and constructing“water-in-salt”electrolyte are other three universal routes from the electrolyte aspect.Furthermore,it is also effective to obtain the high-voltage aqueous SCs through asymmetric design,such as designing asymmetric SCs.The confronting challenges and future development tendency towards the high-voltage aqueous SCs are further discussed.展开更多
Activated carbons have been widely employed as electrode materials of aqueous supercapacitors but the use of hazardous and corrosive activating agents challenges conventional activation procedures.Here,using a unique ...Activated carbons have been widely employed as electrode materials of aqueous supercapacitors but the use of hazardous and corrosive activating agents challenges conventional activation procedures.Here,using a unique molten salt assisted self-activation technique,we have devised an eco-friendly and simple method to synthesize oxygen-rich hierarchical porous carbon with controllable architecture.Mixture of sodium carboxymethylcellulose and NaCl was pyrolyzed in one step,creating in-situ produced Na_(2)CO_(3)-NaCl molten salt that carried out the activation work.Na2 CO3 acts as the activating agent in the reaction media of NaCl during the self-activation process.The obtained carbon exhibited a remarkable specific capacitance of 278 F g^(−1) at 0.5 A g^(−1) and retained 76%capacitance at 50 A g^(−1) in a three-electrode cell.The fabricated aqueous coin cell achieved 81%capacitance retention at 50 A g^(−1) and the highest specific energy density of 12.8 Wh kg^(−1) at 214.6 W kg^(−1),which are superior compared to the commercial activated carbon(64%at 50 A g^(−1) and 8.4 Wh kg^(−1) at 194.8 W kg^(−1)).Moreover,capacitance fading was not observed after 10000 cycles at 5 A g^(−1).Considering the species diversity and low cost of self-salt polymers on the market,this strategy will expect to become a scalable approach for synthesizing high-performance capacitive carbons.展开更多
Aqueous supercapacitors(SCs)have received considerable attention owing to the utilization of low-cost,non-flammable,and low-toxicity aqueous electrolytes thus could eliminate the safety and cost concerns,but their wid...Aqueous supercapacitors(SCs)have received considerable attention owing to the utilization of low-cost,non-flammable,and low-toxicity aqueous electrolytes thus could eliminate the safety and cost concerns,but their wide temperature range applications have generally suffered from frozen of electrolyte and insufficient ionic conductivity at low temperatures.Herein,we demonstrate the feasibility of using an unconventional Deep Eutectic Solvent(DES)based on H2O-Mg(ClO4)2·6 H2O binary system as electrolyte to construct all-climate aqueous carbon-based SC.This unconventional class DES completely base on inorganic substances and achieving simply mix inexpensive salts and water together at the right proportions.Attributed to the attractive feature of extremely low freeze temperature of-69℃,this electrolyte can enable the 1.8 V carbon-based SC to fully work at-40℃with outstanding cycling stability.This DES electrolyte comprising of a single salt and a single solvent without any additive will open up an avenue for developing simple and green electrolytes to construct all-climate SC.展开更多
The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explo...The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explore a candidate with large SCs,which can stably operate in the negative potential region mean-while.For this propose,we design and fabricate solid-solution Ru_(x)Cu_(1-x)O_(2) nanocrystals(NCs),which exhibit competitive SCs and electrochemical stability within the potential range from-0.9 V to 0.0 V in the aqueous KOH electrolyte.The incorporation of Cu enhances the electrochemical utilization of RuO_(2),reaction kinetics,electronic conductivity,and hydrogen evolution overpotentials,which are all highly dependent upon the added contents of Cu species.The optimized Ru_(0.8)Cu_(0.2)O_(2)(RuCu82)electrode of a high mass loading of 5 mg cm^(-2) reveals the best electrochemical capacitances in terms of reversible SCs and capacitance degradation at room temperature and-20℃.Furthermore,the reversible K^(+)-(de)intercalation induced pseudocapacitance is proposed for electrochemical charge storage process of RuCu82.In particu-lar,remarkable specific energy of 59.1 Wh kg-1 at 400 W kg-1 and excellent cycling stability are achieved in the assembled NiCoO_(2)//RuCu82 AHCs.Our contribution here presents a new promising negative elec-trode platform with high SCs and electrochemical stability for next-generation AHCs.展开更多
Aqueous supercapacitors(SCs)have attracted more and more attention for their safety,fast charge/discharge capability and ultra-long life.However,the application of aqueous SCs is limited by the low working voltage due...Aqueous supercapacitors(SCs)have attracted more and more attention for their safety,fast charge/discharge capability and ultra-long life.However,the application of aqueous SCs is limited by the low working voltage due to the narrow electrochemical stability window(ESW)of wate r.Herein,we report a new"water in salt"(WIS)electrolyte by dissolving potassium bis(fluorosulfonyl)amide(KFSI)in water with an ultra-high mass molar concentration of 37 mol/kg.The highly concentrated electrolyte can achieve a wide ESW of 2.8 V.The WIS electrolyte enables a safe carbon-based symmetrical supercapacitor to operate stably at 2.3 V with an ultra-long cycle life and excellent rate performance.The energy density reaches 20.5 Wh/kg at 2300 W/kg,and the capacity retention is 83.5%after 50,000 cycles at a current density of 5 A/g.This new electrolyte will be a promising candidate for future high-voltage aqueous supercapacitors.展开更多
Commercial carbon clothes have the potential to be utilized as supercapacitor electrodes due to their low cost and high conductivity.However,the negligible surface area of the carbon clothes serves as a serious impedi...Commercial carbon clothes have the potential to be utilized as supercapacitor electrodes due to their low cost and high conductivity.However,the negligible surface area of the carbon clothes serves as a serious impediment to their utilization.Herein,we report a facile calcination activation method for carbon cloths to realize remarkable comprehensive electrochemical performance.The activated carbon cloths deliver a high areal capacitance(1700 mF/cm^2),good rate capability,and stable cycling performance up to 20,000 cycles.Owing to the stability in the wide potential window,a designed symmetric capacitor can function in a cell voltage of 2.0 V and delivers high volumetric and gravimetric energy densities of 7.62 mWh/cm^3 and 18.2 Wh/kg,respectively.The remarkable electrochemical performance is attributed to rich microporosity with high surface area,superior electrolyte wettability,and stability in wide potential window.展开更多
Owing to uncontrolled and uneven electrodeposition and side reactions,Zn metal anodes inevitably suffer from issues such as dendrite growth,hydrogen evolution reactions,and surface passivation.This paper proposes an e...Owing to uncontrolled and uneven electrodeposition and side reactions,Zn metal anodes inevitably suffer from issues such as dendrite growth,hydrogen evolution reactions,and surface passivation.This paper proposes an efficient strategy to address these critical issues for realizing long-life and high-capacity aqueous zinc-ion hybrid supercapacitors(ZHSCs)by incorporating low-concentration(0.05 mol·L^(-1))redox RbI electrolyte additives.Specifically,rubidium cations have the ability to influence the negative Zn electrode surface via an electrostatic shielding mechanism,effectively protecting the electrode and minimizing undesired side reactions.In an aqueous solution,iodide anions actively solvate Zn^(2+)ions by stabilizing and modulating the solvation shell surrounding Zn^(2+).Moreover,the presence of iodide ions promotes the uniform deposition of Zn^(2+)species by selective adsorption onto the electrode surface.The synergistic effect of the electrostatic shielding and halogen ions enables the realization of aqueous symmetric Zn||Zn cells with a substantial cycle life of more than 2000 h Additionally,when applied to commercial activated carbon(AC),the proposed strategy facilitates the development of aqueous ZHSCs,exhibiting high specific capacitances(148.8 F·g^(-1)at 4 A·g^(-1))and ultra-long cycling stability.展开更多
Nitrogen doping is usually adopted in carbon based supercapacitor to enhance its relatively low energy density by providing extra pseudocapacity.However,the improvement of energy density is normally limited because th...Nitrogen doping is usually adopted in carbon based supercapacitor to enhance its relatively low energy density by providing extra pseudocapacity.However,the improvement of energy density is normally limited because the content of the introduced nitrogen species is not high and meanwhile only part of them is electrochemically active.Herein,we designed and fabricated a class of hierarchical nitrogen-rich porous carbons(HNPCs)possessing not only very high nitrogen content(up to 21.7 atom%)but also fully electrochemically active nitrogen species(i.e.,pyridinic N,pyrrolic N and oxidized N).Especially,in the synthesis of HNPCs,graphitic carbon nitride(g-C3N4)was used in situ not only as a nitrogen source but also as a catalyst to facilitate the polymerization of phenol and formaldehyde(as carbon precursor)and as a template to create the hierarchical porous structure.As electrodes for aqueous symmetric supercapacitor,the HNPCs with full faradaic-active nitrogen functionalities exhibit excellent supercapacitor performance:high energy density of 36.8 Wh/kg at 2.0 kW/kg(maintaining 25.7 Wh/kg at 38 kW/kg),superior rate capability with 78%capacitance retention from 1.0 to 20 A/g and excellent cycling stability with over95%capacitance retention after 10000 cycles,indicating their promising application potential in electrochemical energy storage.This novel carbon material with high-content and full electrochemically active nitrogen species may find extensive potential applications in the energy storage/conversion,catalysis,adsorption,and so on.展开更多
Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets ...Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.展开更多
Supercapacitors,also known as electrical double-layer capacitors(EDLCs),store and release electrical charge through the adsorption and desorption of ions on the surface of highly porous carbon materials[1].To meet the...Supercapacitors,also known as electrical double-layer capacitors(EDLCs),store and release electrical charge through the adsorption and desorption of ions on the surface of highly porous carbon materials[1].To meet the increasing demands from electric vehicles,rail traffic,military and space applications,EDLCs are usually required to operate within a broad temperature range(subzero to 60°C or more)[2].展开更多
Development of cost-effective and environmental friendly energy storage devices(ESDs) has attracted widespread attention in recent scenario of energy research.Recently,the environmentally viable "water-in-salt&qu...Development of cost-effective and environmental friendly energy storage devices(ESDs) has attracted widespread attention in recent scenario of energy research.Recently,the environmentally viable "water-in-salt"(WiS) electrolytes has received significant interest for the development of advanced high performance ESDs.The WiS electrolyte exhibits wide electrochemical stability window(ESW),highsafety,non-flammability and superior electrochemical performance compared to the conventional "salt-in-water" electrolytes.This review aims to provide a comprehensive discussion on WiS electrolyte based on theoretical,electrochemical and physicochemical characteristics.A strategic way for the usage of WiS electrolyte in rechargeable metal-ion batteries and supercapacitors with potentially improved electrochemical performance has been reviewed systematically.This review also discussed the unique advantages of WiS electrolytes as well as the future scope and challenges.展开更多
Supercapacitors display promising electrochemical performance with high power density and excellent cycle stability.However,their low energy density limits their advancement in a broader range of applications.To enhan...Supercapacitors display promising electrochemical performance with high power density and excellent cycle stability.However,their low energy density limits their advancement in a broader range of applications.To enhance their energy density,we proposed self-assembled spinel NiMn2S4nanoflakes grown on nickel foam which we successfully prepared by a facile hydrothermal method.The NiMn2S4electrode delivers a high capacitance of 2096.7 F g^(-1)at 1.0 A g^(-1),with an exceptional rate capability(~720.6 F g^(-1)at a very high current density of 100 A g^(-1))and good cycle stability(~85.1%retention of the initial capacitance after 7000 cycles with the Coulombic efficiency around 100%).The as-fabricated asymmetric supercapacitors based on NiMn2S4nanoflakes//active carbon demonstrate an energy density of 73.6 W h kg^(-1)at 800.5 W kg^(-1)and adequate cycling performance of~84.6%capacitance retention at 15 A g^(-1)after 10000 cycles.The results reveal that the nanostructured NiMn2S4is an excellent electrode material for high-performance energy storage applications.展开更多
In this paper,we report a high-performance selfsupported supercapacitor electrode composed of a cracked bark-shaped Ni-Co-Mn ternary metallic sulfide(NiCoMnS4)nanostructure on carbon cloth prepared by a simple one-ste...In this paper,we report a high-performance selfsupported supercapacitor electrode composed of a cracked bark-shaped Ni-Co-Mn ternary metallic sulfide(NiCoMnS4)nanostructure on carbon cloth prepared by a simple one-step hydrothermal process and subsequent electrochemical treatment.The electrode delivers a high specific discharge capacity of up to 2470.4 F g^(-1) at 1 A g^(-1) and high rate performances of1635.6 F g^(-1) at 10 A g^(-1) and 910.2 F g^(-1) even at 32 A g^(-1).Cycling tests indicate that NiCoMnS_(4) could maintain >91.1% of its initial capacity and nearly 100% Coulombic efficiency over10,000 cycles at 8 A g^(-1).An aqueous asymmetric supercapacitor assembled with NiCoMnS_(4) as the cathode,activated carbon as the anode,and 1 mol L^(-1) KOH as the electrolyte delivers an energy density of 68.2 W h kg^(-1)at 850.1 W kg^(-1) and capacity retention of 92.5% after 10,000 cycles at 4 A g^(-1).Given the excellent performance and simple material preparation of our proposed device,this study provides a valuable foundation for the development of self-supported metallic sulfide-based electrodes with high electrochemical properties for potential application in aqueous asymmetric supercapacitors.展开更多
Aqueous hybrid supercapacitors(AHSCs)offer potential safety and eco-friendliness compared with conventional electrochemical energy storage devices that use toxic and flammable organic electrolytes.They can serve as th...Aqueous hybrid supercapacitors(AHSCs)offer potential safety and eco-friendliness compared with conventional electrochemical energy storage devices that use toxic and flammable organic electrolytes.They can serve as the bridge between aqueous batteries and aqueous supercapacitors by combining the advantages of high energy of the battery electrode and high power as well as long lifespan of the capacitive electrode.Over the past few decades,extensive research efforts have been devoted to developing advanced materials and fascinating device architectures for AHSCs.However,further development related to the compatibilities between the battery-type electrode and capacitive electrode remains stagnant mainly due to discrepancy encountered in terms of reaction kinetics and capacity.This review focuses on the recent progress made in the field of AHSCs via elucidating the main concepts on the design of battery and capacitive electrodes and emerging electrolytes.In particular,ingenious AHSCs that possess either better flexibility toward materials selection or better device functionality such as those with“dual-ion”energy storage mechanism and non-polarity feature are also discussed.Recent advances and unresolved issues in multivalent ion hybrid devices(in particular,zinc-ion AHSCs)are further outlined.Finally,future research directions and challenges for AHSCs are presented,which are anticipated to deliver higher energy and demonstrate greater multifunctionalities for more breakthrough technology applications.展开更多
In this work,we report a high-performance self-standing supercapacitor electrode of mixed nickel manganese sulfides (NMSs)with a cracked-bark shape grown by one-step electrochemical deposition on activated carbon clot...In this work,we report a high-performance self-standing supercapacitor electrode of mixed nickel manganese sulfides (NMSs)with a cracked-bark shape grown by one-step electrochemical deposition on activated carbon cloth (ACC).The electrode possesses outstanding electrochemical properties,including a high specific capacitance of up to 3142.8 F g^(-1)at 1.0 A g^(-1),the high-rate performance (~1206.8 F g^(-1)at 60.0 A g^(-1)),and cycle stability (~92.3%capacitance retention after 8000 cycles at8 A g^(-1)).An asymmetric supercapacitor assembled using NMSs on ACC as the cathode,activated carbon on carbon cloth as the anode and 1.0 mol L;KOH as the electrolyte delivers a high energy density of 111.2 W h kg^(-1)at 800.0 W kg^(-1)and the prominent cycling performance of~93.2%capacitance retention after 10000 cycles at 5 A g^(-1)with the Columbic efficiency of around 100%during these 10000 cycles.The high performance and facile preparation indicate that the NMSs on ACC hold a huge potential as the electrode for supercapacitors.展开更多
Flexible energy storage systems are promising and efficient technologies for realizing large-scale application of portable,bendable,and wearable electronic devices.Among these systems,aqueous hybrid supercapacitors(AH...Flexible energy storage systems are promising and efficient technologies for realizing large-scale application of portable,bendable,and wearable electronic devices.Among these systems,aqueous hybrid supercapacitors(AHSs)fabricated using redox-active materials with a positive voltage window in aqueous electrolytes and capacitive carbon materials have attracted enormous attention due to their advantages,including a wide operating voltage,a high energy density,a high power density,a long cycling lifespan,and low cost.Thus far,considerable efforts have been made to develop flexible AHSs constructed from various free-standing and flexible electrodes.However,optimizing the configurations of flexible electrodes and the interfacial interaction between flexible substrates and electroactive materials to fully develop the performance through their synergistic effects remains a major challenge.Herein,we have reviewed and summarized recent advances in flexible electrode materials with a variety of configurations based on porous metal supports,carbon substrates,including carbon nanotube networks,graphene and wearable carbon(carbon fibers,carbon cloth,carbon fabric,etc.),and other flexible materials for high-performance AHSs.These flexible electrodes show unique configurations and optimized interfacial structures,resulting in excellent electrochemical performance and superior mechanical stability in AHSs under various harsh conditions,and have great potential for practical applications.Furthermore,the future directions and perspectives for constructing flexible electrodes with novel configurations and AHSs are outlined and discussed,including(1)fabrication of compressible,ultralight,or transparent flexible electrodes for special needs;(2)tailoring and tuning of interfacial properties with robust adhesion between electroactive materials and flexible substrates;(3)development of advanced in situ characterization techniques to uncover the structure evolution rules of flexible electrodes under the operation conditions;(4)matching and optimization of flexible positive and negative electrode materials to assemble advanced AHS devices;(5)design of multifunctional flexible electrodes and AHSs by integrating other specific functions,etc.This timely review is believed to provide deep insights into the intensive research on flexible aqueous energy storage devices.展开更多
Zn metal anodes are usually subject to grave dendrite growth during platting/stripping,which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors.To address above problems,in our work,a novel ...Zn metal anodes are usually subject to grave dendrite growth during platting/stripping,which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors.To address above problems,in our work,a novel phosphorus-functionalized multichannel carbon interlayer was designed and covered on Zn anodes.The results demonstrated that the multichannel structure combined with the three-dimensional meshy skeleton can provide more sufficient space for Zn deposition,thereby effectively inhibiting the growth of zinc dendrites.Meanwhile,theoretical calculations also confirmed that the P-C and P=O functional groups from phosphorus-functionalized multichannel carbon interlayer have the decisive influence in reducing the zinc nucleation potential and depositing uniformly zinc.Concretely,the symmetrical battery assembled with phosphorus-functionalized multichannel carbon interlayer-covered Zn anodes possessed a long lifetime of 3300 h at 2 mA cm^(-2)with 1 mAh cm^(-2).Furthermore,the full cell with activated carbon cathodes exhibited a high specific capacity of 80.5 mAh g^(-1)and outstanding cycling stability without capacity decay after 15000 cycles at a high current density of 5 A g^(-1).The superior electrochemical performance exceeded that of most reported papers.Consequently,our synthesized zincophilic interlayer with the unique structure has superior prospects for application in stabilizing zinc anodes and prolonging the lifespan of batteries.展开更多
Aqueous electrolytes offer superior prospects for advanced energy storage.“Water-in-salt”(WIS)electrolytes exhibit a wide electrochemical stability window(ESW),but their low conductivity,high viscosity,and precipita...Aqueous electrolytes offer superior prospects for advanced energy storage.“Water-in-salt”(WIS)electrolytes exhibit a wide electrochemical stability window(ESW),but their low conductivity,high viscosity,and precipitation at low temperatures restrict their application.Herein,we report a novel localized“water-in-pyrrolidinium chloride”electrolyte(LWIP;1 mol/L,N-propyl-N-methylpyrrolidinium chloride/(water and N,Ndimethylformamide,1:4 by molality))enabling high-voltage,low-temperature supercapacitors(SCs).The greatly improved ESW(3.451 V)is mainly attributed to the strong solvation between Cl-and water molecules,which broadens the negative stability.This water-binding mechanism is very different from that of a WIS electrolyte based on alkali metal salt.SCs using LWIP electrolytes not only yield a high operating voltage of 2.4 V and excellent capacity retention(82.8%after 15,000 cycles at 5 A g^(-1))but also operate stably at-20℃.This work provides new approaches for the design and preparation of novel electrolytes.展开更多
本文介绍了一种由水热生长的MnCo_(2)O_(4)(MCO)纳米线以及随后电沉积的NiCoMnS_(4)(NCMS)纳米片组成的高性能超级电容器电极材料,即泡沫镍上生长的MCO@NCMS.由于其多孔和互联的纳米结构以及MCO和NCMS的协同效应,在1 mA cm^(-2)处实现了...本文介绍了一种由水热生长的MnCo_(2)O_(4)(MCO)纳米线以及随后电沉积的NiCoMnS_(4)(NCMS)纳米片组成的高性能超级电容器电极材料,即泡沫镍上生长的MCO@NCMS.由于其多孔和互联的纳米结构以及MCO和NCMS的协同效应,在1 mA cm^(-2)处实现了12,020.8 mF cm^(-2)的高电容,并展现出良好的倍率性能以及循环稳定性.电化学测试表明,组装成的水性非对称超级电容器在0.800 mW cm^(-2)的功率密度下,达到0.611 mW h cm^(-2)的高能量密度并具有良好的循环稳定性,即在15,000次充放电循环后,容量保持率可达90%,且保持100%的库仑效率.展开更多
基金financially supported by research grants from the Natural Science Foundation of China(51702032)Natural Science Foundation of Chongqing(cstc2018jcyjAX0375)+1 种基金Fundamental Research Funds for the Central Universities(2019CDXYDL0007)Key Innovation Project for Clinical Technology of the Second Affiliated Hospital of Army Medical University(2018JSLC0025).
文摘Due to its ultra-fast charge/discharge rate,long cyclic life span,and environmental benignity,aqueous supercapacitor(SC)is considered as a proper nextgeneration energy storage device.Unfortunately,limited by undesirable water electrolysis and unreasonable electrode potential range,aqueous SC normally generates a narrow cell voltage,resulting in a low energy density.To address such challenge,enormous efforts have been made to construct high-voltage aqueous SCs.Despite these achievements,the systematic reviews about this field are still rare.To fill this knowledge gap,this review summarizes the recent advances about boosting the cell voltage of aqueous SCs.From the viewpoint of electrode,doping alkali cations,modulating the electrode mass ratio,and optimizing the surface charge density are regarded as three effective pathways to achieve this goal.However,adjusting the appropriate pH level,introducing redox mediators,and constructing“water-in-salt”electrolyte are other three universal routes from the electrolyte aspect.Furthermore,it is also effective to obtain the high-voltage aqueous SCs through asymmetric design,such as designing asymmetric SCs.The confronting challenges and future development tendency towards the high-voltage aqueous SCs are further discussed.
基金financial support from the Australian Research Council Discovery Programs(Nos.DP190103661 and DP220103229)the Australian Government Research Training Program Scholarship.
文摘Activated carbons have been widely employed as electrode materials of aqueous supercapacitors but the use of hazardous and corrosive activating agents challenges conventional activation procedures.Here,using a unique molten salt assisted self-activation technique,we have devised an eco-friendly and simple method to synthesize oxygen-rich hierarchical porous carbon with controllable architecture.Mixture of sodium carboxymethylcellulose and NaCl was pyrolyzed in one step,creating in-situ produced Na_(2)CO_(3)-NaCl molten salt that carried out the activation work.Na2 CO3 acts as the activating agent in the reaction media of NaCl during the self-activation process.The obtained carbon exhibited a remarkable specific capacitance of 278 F g^(−1) at 0.5 A g^(−1) and retained 76%capacitance at 50 A g^(−1) in a three-electrode cell.The fabricated aqueous coin cell achieved 81%capacitance retention at 50 A g^(−1) and the highest specific energy density of 12.8 Wh kg^(−1) at 214.6 W kg^(−1),which are superior compared to the commercial activated carbon(64%at 50 A g^(−1) and 8.4 Wh kg^(−1) at 194.8 W kg^(−1)).Moreover,capacitance fading was not observed after 10000 cycles at 5 A g^(−1).Considering the species diversity and low cost of self-salt polymers on the market,this strategy will expect to become a scalable approach for synthesizing high-performance capacitive carbons.
基金financially supported by the DNL Cooperation Fund,Chinese Academy of Sciences(DNL180307)Natural Science Foundation of Gansu Province(18JR3RA159)。
文摘Aqueous supercapacitors(SCs)have received considerable attention owing to the utilization of low-cost,non-flammable,and low-toxicity aqueous electrolytes thus could eliminate the safety and cost concerns,but their wide temperature range applications have generally suffered from frozen of electrolyte and insufficient ionic conductivity at low temperatures.Herein,we demonstrate the feasibility of using an unconventional Deep Eutectic Solvent(DES)based on H2O-Mg(ClO4)2·6 H2O binary system as electrolyte to construct all-climate aqueous carbon-based SC.This unconventional class DES completely base on inorganic substances and achieving simply mix inexpensive salts and water together at the right proportions.Attributed to the attractive feature of extremely low freeze temperature of-69℃,this electrolyte can enable the 1.8 V carbon-based SC to fully work at-40℃with outstanding cycling stability.This DES electrolyte comprising of a single salt and a single solvent without any additive will open up an avenue for developing simple and green electrolytes to construct all-climate SC.
基金supported by the National Natural Science Foundation of China(Nos.U22A20145,51904115,52072151,52171211,and 52271218)Jinan Independent Innovative Team(No.2020GXRC015)the Major Program of Shandong Province Natural Science Foundation(Nos.ZR2023ZD43 and ZR2021ZD05).
文摘The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explore a candidate with large SCs,which can stably operate in the negative potential region mean-while.For this propose,we design and fabricate solid-solution Ru_(x)Cu_(1-x)O_(2) nanocrystals(NCs),which exhibit competitive SCs and electrochemical stability within the potential range from-0.9 V to 0.0 V in the aqueous KOH electrolyte.The incorporation of Cu enhances the electrochemical utilization of RuO_(2),reaction kinetics,electronic conductivity,and hydrogen evolution overpotentials,which are all highly dependent upon the added contents of Cu species.The optimized Ru_(0.8)Cu_(0.2)O_(2)(RuCu82)electrode of a high mass loading of 5 mg cm^(-2) reveals the best electrochemical capacitances in terms of reversible SCs and capacitance degradation at room temperature and-20℃.Furthermore,the reversible K^(+)-(de)intercalation induced pseudocapacitance is proposed for electrochemical charge storage process of RuCu82.In particu-lar,remarkable specific energy of 59.1 Wh kg-1 at 400 W kg-1 and excellent cycling stability are achieved in the assembled NiCoO_(2)//RuCu82 AHCs.Our contribution here presents a new promising negative elec-trode platform with high SCs and electrochemical stability for next-generation AHCs.
基金supported by the Shenzhen Science and Technology Innovation Commission(Nos.JCYJ20180504165506495,JCYJ20170818085823773)。
文摘Aqueous supercapacitors(SCs)have attracted more and more attention for their safety,fast charge/discharge capability and ultra-long life.However,the application of aqueous SCs is limited by the low working voltage due to the narrow electrochemical stability window(ESW)of wate r.Herein,we report a new"water in salt"(WIS)electrolyte by dissolving potassium bis(fluorosulfonyl)amide(KFSI)in water with an ultra-high mass molar concentration of 37 mol/kg.The highly concentrated electrolyte can achieve a wide ESW of 2.8 V.The WIS electrolyte enables a safe carbon-based symmetrical supercapacitor to operate stably at 2.3 V with an ultra-long cycle life and excellent rate performance.The energy density reaches 20.5 Wh/kg at 2300 W/kg,and the capacity retention is 83.5%after 50,000 cycles at a current density of 5 A/g.This new electrolyte will be a promising candidate for future high-voltage aqueous supercapacitors.
基金supported by the National Natural Science Fund for Distinguished Young Scholars(No.51425204)the National Natural Science Foundation of China(No.51521001)+2 种基金the National Key Research and Development Program of China(No.2016YFA0202603)the Programme of Introducing Talents of Discipline to Universities(No.B17034)the Yellow Crane Talent(Science&Technology)Program of Wuhan City。
文摘Commercial carbon clothes have the potential to be utilized as supercapacitor electrodes due to their low cost and high conductivity.However,the negligible surface area of the carbon clothes serves as a serious impediment to their utilization.Herein,we report a facile calcination activation method for carbon cloths to realize remarkable comprehensive electrochemical performance.The activated carbon cloths deliver a high areal capacitance(1700 mF/cm^2),good rate capability,and stable cycling performance up to 20,000 cycles.Owing to the stability in the wide potential window,a designed symmetric capacitor can function in a cell voltage of 2.0 V and delivers high volumetric and gravimetric energy densities of 7.62 mWh/cm^3 and 18.2 Wh/kg,respectively.The remarkable electrochemical performance is attributed to rich microporosity with high surface area,superior electrolyte wettability,and stability in wide potential window.
基金financially supported by the National Natural Science Foundation of China(No.22209101)National Key R&D Program of China(No.2020YFA0710500)the Key Research and Development Program of Shaanxi(No.2022GXLH-01-23)for financial support。
文摘Owing to uncontrolled and uneven electrodeposition and side reactions,Zn metal anodes inevitably suffer from issues such as dendrite growth,hydrogen evolution reactions,and surface passivation.This paper proposes an efficient strategy to address these critical issues for realizing long-life and high-capacity aqueous zinc-ion hybrid supercapacitors(ZHSCs)by incorporating low-concentration(0.05 mol·L^(-1))redox RbI electrolyte additives.Specifically,rubidium cations have the ability to influence the negative Zn electrode surface via an electrostatic shielding mechanism,effectively protecting the electrode and minimizing undesired side reactions.In an aqueous solution,iodide anions actively solvate Zn^(2+)ions by stabilizing and modulating the solvation shell surrounding Zn^(2+).Moreover,the presence of iodide ions promotes the uniform deposition of Zn^(2+)species by selective adsorption onto the electrode surface.The synergistic effect of the electrostatic shielding and halogen ions enables the realization of aqueous symmetric Zn||Zn cells with a substantial cycle life of more than 2000 h Additionally,when applied to commercial activated carbon(AC),the proposed strategy facilitates the development of aqueous ZHSCs,exhibiting high specific capacitances(148.8 F·g^(-1)at 4 A·g^(-1))and ultra-long cycling stability.
基金supported by the National Natural Science Foundation of China(21773112,21173119,and 21273109)the Natural Science Foundation of Hubei Province(2019CFB626)+1 种基金the Initial Research Fund(2042019023)the Cultivation Fund(204201814003)of Huanggang Normal University。
文摘Nitrogen doping is usually adopted in carbon based supercapacitor to enhance its relatively low energy density by providing extra pseudocapacity.However,the improvement of energy density is normally limited because the content of the introduced nitrogen species is not high and meanwhile only part of them is electrochemically active.Herein,we designed and fabricated a class of hierarchical nitrogen-rich porous carbons(HNPCs)possessing not only very high nitrogen content(up to 21.7 atom%)but also fully electrochemically active nitrogen species(i.e.,pyridinic N,pyrrolic N and oxidized N).Especially,in the synthesis of HNPCs,graphitic carbon nitride(g-C3N4)was used in situ not only as a nitrogen source but also as a catalyst to facilitate the polymerization of phenol and formaldehyde(as carbon precursor)and as a template to create the hierarchical porous structure.As electrodes for aqueous symmetric supercapacitor,the HNPCs with full faradaic-active nitrogen functionalities exhibit excellent supercapacitor performance:high energy density of 36.8 Wh/kg at 2.0 kW/kg(maintaining 25.7 Wh/kg at 38 kW/kg),superior rate capability with 78%capacitance retention from 1.0 to 20 A/g and excellent cycling stability with over95%capacitance retention after 10000 cycles,indicating their promising application potential in electrochemical energy storage.This novel carbon material with high-content and full electrochemically active nitrogen species may find extensive potential applications in the energy storage/conversion,catalysis,adsorption,and so on.
基金the funding from Natural Science Foundation of China(No.52003163)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515010670)+1 种基金Science and Technology Innovation Commission of Shenzhen(Nos.KQTD20170810105439418 and 20200812112006001)NTUT-SZU Joint Research Program(Nos.2022005 and 2022015)
文摘Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.
基金supported by the National Natural Science Foundation of China(52272224 and 51902188)the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(AMGM2024F26)。
文摘Supercapacitors,also known as electrical double-layer capacitors(EDLCs),store and release electrical charge through the adsorption and desorption of ions on the surface of highly porous carbon materials[1].To meet the increasing demands from electric vehicles,rail traffic,military and space applications,EDLCs are usually required to operate within a broad temperature range(subzero to 60°C or more)[2].
基金the Council of Scientific & Industrial Research(CSIR) for the financial support through the HCP-44/02/1 projectthe DST-INSPIRE Faculty Scheme,Department of Science and Technology,New Delhi,Govt.of India(IFA20-MS-168) for the financial supports。
文摘Development of cost-effective and environmental friendly energy storage devices(ESDs) has attracted widespread attention in recent scenario of energy research.Recently,the environmentally viable "water-in-salt"(WiS) electrolytes has received significant interest for the development of advanced high performance ESDs.The WiS electrolyte exhibits wide electrochemical stability window(ESW),highsafety,non-flammability and superior electrochemical performance compared to the conventional "salt-in-water" electrolytes.This review aims to provide a comprehensive discussion on WiS electrolyte based on theoretical,electrochemical and physicochemical characteristics.A strategic way for the usage of WiS electrolyte in rechargeable metal-ion batteries and supercapacitors with potentially improved electrochemical performance has been reviewed systematically.This review also discussed the unique advantages of WiS electrolytes as well as the future scope and challenges.
基金partly supported by the Natural Science Foundation of Gansu,China(Grant Nos.22YF7GA009 and 20JR10RA611)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2021 sp54)。
文摘Supercapacitors display promising electrochemical performance with high power density and excellent cycle stability.However,their low energy density limits their advancement in a broader range of applications.To enhance their energy density,we proposed self-assembled spinel NiMn2S4nanoflakes grown on nickel foam which we successfully prepared by a facile hydrothermal method.The NiMn2S4electrode delivers a high capacitance of 2096.7 F g^(-1)at 1.0 A g^(-1),with an exceptional rate capability(~720.6 F g^(-1)at a very high current density of 100 A g^(-1))and good cycle stability(~85.1%retention of the initial capacitance after 7000 cycles with the Coulombic efficiency around 100%).The as-fabricated asymmetric supercapacitors based on NiMn2S4nanoflakes//active carbon demonstrate an energy density of 73.6 W h kg^(-1)at 800.5 W kg^(-1)and adequate cycling performance of~84.6%capacitance retention at 15 A g^(-1)after 10000 cycles.The results reveal that the nanostructured NiMn2S4is an excellent electrode material for high-performance energy storage applications.
基金supported by the National Natural Science Foundation of China(61376068,11304132,11304133 and11504147)the Fundamental Research Funds for the Central Universities(lzujbky-2017-178 and lzujbky-2017-181)。
文摘In this paper,we report a high-performance selfsupported supercapacitor electrode composed of a cracked bark-shaped Ni-Co-Mn ternary metallic sulfide(NiCoMnS4)nanostructure on carbon cloth prepared by a simple one-step hydrothermal process and subsequent electrochemical treatment.The electrode delivers a high specific discharge capacity of up to 2470.4 F g^(-1) at 1 A g^(-1) and high rate performances of1635.6 F g^(-1) at 10 A g^(-1) and 910.2 F g^(-1) even at 32 A g^(-1).Cycling tests indicate that NiCoMnS_(4) could maintain >91.1% of its initial capacity and nearly 100% Coulombic efficiency over10,000 cycles at 8 A g^(-1).An aqueous asymmetric supercapacitor assembled with NiCoMnS_(4) as the cathode,activated carbon as the anode,and 1 mol L^(-1) KOH as the electrolyte delivers an energy density of 68.2 W h kg^(-1)at 850.1 W kg^(-1) and capacity retention of 92.5% after 10,000 cycles at 4 A g^(-1).Given the excellent performance and simple material preparation of our proposed device,this study provides a valuable foundation for the development of self-supported metallic sulfide-based electrodes with high electrochemical properties for potential application in aqueous asymmetric supercapacitors.
基金supported by the National Natural Science Foundation of China(51972257,52072136 and 51872104)the National Key R&D Program of China(2016YFA0202602)the Natural Science Foundation of Hubei Province(2018CFB581).
文摘Aqueous hybrid supercapacitors(AHSCs)offer potential safety and eco-friendliness compared with conventional electrochemical energy storage devices that use toxic and flammable organic electrolytes.They can serve as the bridge between aqueous batteries and aqueous supercapacitors by combining the advantages of high energy of the battery electrode and high power as well as long lifespan of the capacitive electrode.Over the past few decades,extensive research efforts have been devoted to developing advanced materials and fascinating device architectures for AHSCs.However,further development related to the compatibilities between the battery-type electrode and capacitive electrode remains stagnant mainly due to discrepancy encountered in terms of reaction kinetics and capacity.This review focuses on the recent progress made in the field of AHSCs via elucidating the main concepts on the design of battery and capacitive electrodes and emerging electrolytes.In particular,ingenious AHSCs that possess either better flexibility toward materials selection or better device functionality such as those with“dual-ion”energy storage mechanism and non-polarity feature are also discussed.Recent advances and unresolved issues in multivalent ion hybrid devices(in particular,zinc-ion AHSCs)are further outlined.Finally,future research directions and challenges for AHSCs are presented,which are anticipated to deliver higher energy and demonstrate greater multifunctionalities for more breakthrough technology applications.
基金supported by the Natural Science Foundation of Gansu,China(Grant No.20JR10RA611)。
文摘In this work,we report a high-performance self-standing supercapacitor electrode of mixed nickel manganese sulfides (NMSs)with a cracked-bark shape grown by one-step electrochemical deposition on activated carbon cloth (ACC).The electrode possesses outstanding electrochemical properties,including a high specific capacitance of up to 3142.8 F g^(-1)at 1.0 A g^(-1),the high-rate performance (~1206.8 F g^(-1)at 60.0 A g^(-1)),and cycle stability (~92.3%capacitance retention after 8000 cycles at8 A g^(-1)).An asymmetric supercapacitor assembled using NMSs on ACC as the cathode,activated carbon on carbon cloth as the anode and 1.0 mol L;KOH as the electrolyte delivers a high energy density of 111.2 W h kg^(-1)at 800.0 W kg^(-1)and the prominent cycling performance of~93.2%capacitance retention after 10000 cycles at 5 A g^(-1)with the Columbic efficiency of around 100%during these 10000 cycles.The high performance and facile preparation indicate that the NMSs on ACC hold a huge potential as the electrode for supercapacitors.
基金supported by the National Natural Science Foundation of China(Nos.22278328,U2003216)the Key Research and Development Program in Shaanxi Province of China(No.2023-YBGY-292)the Fundamental Research Funds for the Central Universities(No.xtr042021009).
文摘Flexible energy storage systems are promising and efficient technologies for realizing large-scale application of portable,bendable,and wearable electronic devices.Among these systems,aqueous hybrid supercapacitors(AHSs)fabricated using redox-active materials with a positive voltage window in aqueous electrolytes and capacitive carbon materials have attracted enormous attention due to their advantages,including a wide operating voltage,a high energy density,a high power density,a long cycling lifespan,and low cost.Thus far,considerable efforts have been made to develop flexible AHSs constructed from various free-standing and flexible electrodes.However,optimizing the configurations of flexible electrodes and the interfacial interaction between flexible substrates and electroactive materials to fully develop the performance through their synergistic effects remains a major challenge.Herein,we have reviewed and summarized recent advances in flexible electrode materials with a variety of configurations based on porous metal supports,carbon substrates,including carbon nanotube networks,graphene and wearable carbon(carbon fibers,carbon cloth,carbon fabric,etc.),and other flexible materials for high-performance AHSs.These flexible electrodes show unique configurations and optimized interfacial structures,resulting in excellent electrochemical performance and superior mechanical stability in AHSs under various harsh conditions,and have great potential for practical applications.Furthermore,the future directions and perspectives for constructing flexible electrodes with novel configurations and AHSs are outlined and discussed,including(1)fabrication of compressible,ultralight,or transparent flexible electrodes for special needs;(2)tailoring and tuning of interfacial properties with robust adhesion between electroactive materials and flexible substrates;(3)development of advanced in situ characterization techniques to uncover the structure evolution rules of flexible electrodes under the operation conditions;(4)matching and optimization of flexible positive and negative electrode materials to assemble advanced AHS devices;(5)design of multifunctional flexible electrodes and AHSs by integrating other specific functions,etc.This timely review is believed to provide deep insights into the intensive research on flexible aqueous energy storage devices.
基金supported by the National Natural Science Foundation(NSFC)of China(22179094)the research funding provided by Cangzhou Institute of Tiangong University(Grant No.TGCYY-Z-0202)
文摘Zn metal anodes are usually subject to grave dendrite growth during platting/stripping,which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors.To address above problems,in our work,a novel phosphorus-functionalized multichannel carbon interlayer was designed and covered on Zn anodes.The results demonstrated that the multichannel structure combined with the three-dimensional meshy skeleton can provide more sufficient space for Zn deposition,thereby effectively inhibiting the growth of zinc dendrites.Meanwhile,theoretical calculations also confirmed that the P-C and P=O functional groups from phosphorus-functionalized multichannel carbon interlayer have the decisive influence in reducing the zinc nucleation potential and depositing uniformly zinc.Concretely,the symmetrical battery assembled with phosphorus-functionalized multichannel carbon interlayer-covered Zn anodes possessed a long lifetime of 3300 h at 2 mA cm^(-2)with 1 mAh cm^(-2).Furthermore,the full cell with activated carbon cathodes exhibited a high specific capacity of 80.5 mAh g^(-1)and outstanding cycling stability without capacity decay after 15000 cycles at a high current density of 5 A g^(-1).The superior electrochemical performance exceeded that of most reported papers.Consequently,our synthesized zincophilic interlayer with the unique structure has superior prospects for application in stabilizing zinc anodes and prolonging the lifespan of batteries.
基金funding provided by Cangzhou Institute of Tiangong University (Grant No.TGCYY-Z-0202)the National Natural Science Foundation of China (22179094)Tianjin Application Foundation and Advanced Technology Research Plan Project (15ZCZDGX00270,14RCHZGX00859).
文摘Aqueous electrolytes offer superior prospects for advanced energy storage.“Water-in-salt”(WIS)electrolytes exhibit a wide electrochemical stability window(ESW),but their low conductivity,high viscosity,and precipitation at low temperatures restrict their application.Herein,we report a novel localized“water-in-pyrrolidinium chloride”electrolyte(LWIP;1 mol/L,N-propyl-N-methylpyrrolidinium chloride/(water and N,Ndimethylformamide,1:4 by molality))enabling high-voltage,low-temperature supercapacitors(SCs).The greatly improved ESW(3.451 V)is mainly attributed to the strong solvation between Cl-and water molecules,which broadens the negative stability.This water-binding mechanism is very different from that of a WIS electrolyte based on alkali metal salt.SCs using LWIP electrolytes not only yield a high operating voltage of 2.4 V and excellent capacity retention(82.8%after 15,000 cycles at 5 A g^(-1))but also operate stably at-20℃.This work provides new approaches for the design and preparation of novel electrolytes.
基金supported by the Natural Science Foundation of Gansu,China(20JR10RA611 and 22YF7GA009)the Fundamental Research Funds for the Central Universities(lzujbky-2021-sp54)。
文摘本文介绍了一种由水热生长的MnCo_(2)O_(4)(MCO)纳米线以及随后电沉积的NiCoMnS_(4)(NCMS)纳米片组成的高性能超级电容器电极材料,即泡沫镍上生长的MCO@NCMS.由于其多孔和互联的纳米结构以及MCO和NCMS的协同效应,在1 mA cm^(-2)处实现了12,020.8 mF cm^(-2)的高电容,并展现出良好的倍率性能以及循环稳定性.电化学测试表明,组装成的水性非对称超级电容器在0.800 mW cm^(-2)的功率密度下,达到0.611 mW h cm^(-2)的高能量密度并具有良好的循环稳定性,即在15,000次充放电循环后,容量保持率可达90%,且保持100%的库仑效率.
