Carbonaceous materials are promising anode candidates for potassium-ion batteries(PIBs)given its high conductivity,stable property,and abundant resource,while its practical implementation is still hampered by its limi...Carbonaceous materials are promising anode candidates for potassium-ion batteries(PIBs)given its high conductivity,stable property,and abundant resource,while its practical implementation is still hampered by its limited capacity and inferior rate behavior.Herein,we report a superior carbonaceous anode through a combined strategy of carbon hybridization and heteroatom doping.In this composite,hollow carbon spindles(HCS)were anchored on the surface of graphene(G)followed with sulfur doping treatment,aiming to integrate the high conductivity of graphene,the good structure stability of HCS,and the S doping-induced ample active sites.As a PIB anode,the S-G@HCS composite can display high capacity(301 mAh g^(-1)at 0.1 A g^(-1)after 500 cycles)and long-term cyclability up to 1800 cycles at 2 A g^(-1).Impressively,it can deliver an outstanding rate capacity of 215 mAh g^(-1)at 10 A g^(-1),which is superior to most carbon anodes as-reported so far for PIBs.Experimental and theoretical analysis manifests that the construction of graphene/amorphous carbon interface as well as S doping enables the regulation of electronic structure and ion adsorption/transportation properties of carbonaceous material,thus accounting for the high capacity and superior rate capability of S-G@HCS composite.展开更多
Although hybrid metal ion capacitors(MICs) are highly desired to achieve both high power density of supercapacitors and high energy density of rechargeable batteries, the mismatch problem of electrochemical kinetics o...Although hybrid metal ion capacitors(MICs) are highly desired to achieve both high power density of supercapacitors and high energy density of rechargeable batteries, the mismatch problem of electrochemical kinetics of negative and positive electrodes in MICs hampers the realization of this goal. Here, a new hybrid capacitor concept-potassium metal capacitor(PMC) is proposed for the first time, where potassium metal and commercial activated carbon(AC) without any modification are applied as negative and positive electrodes, respectively, and the electrolyte is the same as that of non-aqueous potassium ion batteries. The simplest PMC prototype exhibits a good combination of high energy density(184.9 Wh kg^(-1)) and power density(12.4 kW kg^(-1)), which benefits from the synergistic effect of potassium metal and AC electrode. The former experiences fast potassium plating/striping during charging and discharging, and the later possesses complex multiple charge behaviors driven by low potential of potassium metal. Specifically, below open-circuit voltage, transportation of solvated cations in AC pores plays an important role;beyond this voltage, synergy actions of cations and anions, including adsorption/desorption of solvated cations and anions, and ions exchange between them, dominate the capacitance contribution. This work enriches the types of MICs, and deepens the understanding of the energy storage mechanism of non-aqueous hybrid metal capacitors.展开更多
Although lithium metal has become a promising anode material for high-energy batteries owing to its high specific capacity and the lowest reduction potential,the continuous side reactions with electrolyte as well as t...Although lithium metal has become a promising anode material for high-energy batteries owing to its high specific capacity and the lowest reduction potential,the continuous side reactions with electrolyte as well as the safety problem caused by Li dendrite growth restrict Li anode’s practical application.Herein,we demonstrate that N-fluoropyridinium(ArF^(+))bis(trifluoromethane)sulfonimide(TFSI-)as an electrolyte additive can protect the lithium metal by both solid electrolyte interphase(SEI)protection and electrostatic repulsion mechanisms.The ArF+cations not only participate in forming F,Ncontaining SEI protective layer on Li surface,but also act as a cationic repellent during Li deposition to inhibit Li dendrite growth.As a result,the cycle performance of Li symmetric cells and Li||LiFePO_(4)full cells were significantly improved by using ArFTFSIadded electrolyte.This study provides an electrolyte additive strategy for Li anode realizing SEI protection and electrostatic repulsion simultaneously.展开更多
With the accelerating advancement of distributed sensors and portable electronic devices in the era of big data,harvesting energy from the surrounding environment to power electrical devices has become increasingly at...With the accelerating advancement of distributed sensors and portable electronic devices in the era of big data,harvesting energy from the surrounding environment to power electrical devices has become increasingly attractive.However,most mechanical energy harvesters often require high operating frequencies to function properly.Moreover,for practical applications,the survivability of devices in harsh operating environments is a vital issuewhich must be addressed.Besides,the single-stimulus responsiveness limits their further applications in complex external environments.Here,a pressure and moisture dual-responsive ionic diode consisting of two organohydrogels with opposite charges as an energy harvester is proposed.The organohydrogel ionic diode utilizes the migration of cations and anions to form the depletion zone and followed by an enhancement of the built-in potential along the depletion zone as a result of mechanical stress or humidity,converting ultralow-frequency mechanical energy or moisture energy into electrical energy.Meanwhile,this mechanism is further confirmed by the finite element analysis.With the increased rectification ratio due to the introduction of MXene,the ionic diode exhibits a relatively large output current(∼10.10μA cm^(−2))and power density(∼0.10μW cm^(−2))at a mechanical pressure of 0.01 Hz,outperforming most currently available mechanical energy harvesters.More impressively,the incorporation of ethylene glycol provides the hydrogel ionic diode with excellent temperature tolerance and long-term environmental stability.The organohydrogel ionic diode can also be applied as a moisture-driven power generator and self-powered humidity sensor.This study presents promising prospects for the efficient collection of renewable and sustainable energy and the practical application of hydrogel-based energy harvesters in extreme environments.展开更多
Graphene coating is commonly used to improve the performance of electrode materials,while its steric hindrance effect hampers fast ion transport with compromised rate capability.Herein,a unique single-walled carbon na...Graphene coating is commonly used to improve the performance of electrode materials,while its steric hindrance effect hampers fast ion transport with compromised rate capability.Herein,a unique single-walled carbon nanotubes(SWNTs)coating layer,as an alternative to graphene,has been developed to improve the battery behavior of iron-based anodes.Benefiting from the structure merits of mesoporous SWNTs layer for fast electron/ion transport and hollow Fe_(3)O_(4) for volume accommodation,as-prepared Fe_(3)O_(4)@SWNTs exhibited excellent lithium storage performance.It delivers a high capacity,excellent rate capability,and long lifespan with capacities of 582 mA·h·g^(-1) at 5 A·g^(-1) and 408 mA·h·g^(-1) at 8 A·g^(-1) remained after 1000 cycles.Such performance is better than graphene-coated Fe_(3)O_(4) and other SWNT-Fe_(3)O_(4) architectures.Besides,SWNTs coating is also used to improve the sodium and potassium storage performance of FeSe_(2).The kinetics analysis and ex-situ experiment further reveal the effect of SWNTs coating for fast electron/ion transfer kinetics and good structure stability,thus leading to the superior performance of SWNTs-coated composites.展开更多
基金supported by National Natural Science Foundation of China(Grant 61935017,21701174,21771182)Projects of International Cooperation and Exchanges NSFC(Grant 51811530018)+2 种基金Synergetic Innovation Center for Organic Electronics and Information Displaysthe Youth Innovation Promotion Associa tion CASthe start-up funding from FJNU。
文摘Carbonaceous materials are promising anode candidates for potassium-ion batteries(PIBs)given its high conductivity,stable property,and abundant resource,while its practical implementation is still hampered by its limited capacity and inferior rate behavior.Herein,we report a superior carbonaceous anode through a combined strategy of carbon hybridization and heteroatom doping.In this composite,hollow carbon spindles(HCS)were anchored on the surface of graphene(G)followed with sulfur doping treatment,aiming to integrate the high conductivity of graphene,the good structure stability of HCS,and the S doping-induced ample active sites.As a PIB anode,the S-G@HCS composite can display high capacity(301 mAh g^(-1)at 0.1 A g^(-1)after 500 cycles)and long-term cyclability up to 1800 cycles at 2 A g^(-1).Impressively,it can deliver an outstanding rate capacity of 215 mAh g^(-1)at 10 A g^(-1),which is superior to most carbon anodes as-reported so far for PIBs.Experimental and theoretical analysis manifests that the construction of graphene/amorphous carbon interface as well as S doping enables the regulation of electronic structure and ion adsorption/transportation properties of carbonaceous material,thus accounting for the high capacity and superior rate capability of S-G@HCS composite.
基金supported by the National Key R&D Program of China (2022YFB2402600)the National Natural Science Foundation of China (22279166, 52203346)+1 种基金Guangdong Basic and Applied Basic Research Foundation (2022B1515120019)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(22qntd0101)。
文摘Although hybrid metal ion capacitors(MICs) are highly desired to achieve both high power density of supercapacitors and high energy density of rechargeable batteries, the mismatch problem of electrochemical kinetics of negative and positive electrodes in MICs hampers the realization of this goal. Here, a new hybrid capacitor concept-potassium metal capacitor(PMC) is proposed for the first time, where potassium metal and commercial activated carbon(AC) without any modification are applied as negative and positive electrodes, respectively, and the electrolyte is the same as that of non-aqueous potassium ion batteries. The simplest PMC prototype exhibits a good combination of high energy density(184.9 Wh kg^(-1)) and power density(12.4 kW kg^(-1)), which benefits from the synergistic effect of potassium metal and AC electrode. The former experiences fast potassium plating/striping during charging and discharging, and the later possesses complex multiple charge behaviors driven by low potential of potassium metal. Specifically, below open-circuit voltage, transportation of solvated cations in AC pores plays an important role;beyond this voltage, synergy actions of cations and anions, including adsorption/desorption of solvated cations and anions, and ions exchange between them, dominate the capacitance contribution. This work enriches the types of MICs, and deepens the understanding of the energy storage mechanism of non-aqueous hybrid metal capacitors.
基金This work was financially supported by the National Key R&D Program of China(No.2022YFB2402600)National Natural Science Foundation of China(No.22279166)+1 种基金Basic and Applied Basic Research Foundation of Guangdong Province-Regional joint fund project(No.2022B1515120019)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(Nos.22qntd0101 and 22dfx01).
文摘Although lithium metal has become a promising anode material for high-energy batteries owing to its high specific capacity and the lowest reduction potential,the continuous side reactions with electrolyte as well as the safety problem caused by Li dendrite growth restrict Li anode’s practical application.Herein,we demonstrate that N-fluoropyridinium(ArF^(+))bis(trifluoromethane)sulfonimide(TFSI-)as an electrolyte additive can protect the lithium metal by both solid electrolyte interphase(SEI)protection and electrostatic repulsion mechanisms.The ArF+cations not only participate in forming F,Ncontaining SEI protective layer on Li surface,but also act as a cationic repellent during Li deposition to inhibit Li dendrite growth.As a result,the cycle performance of Li symmetric cells and Li||LiFePO_(4)full cells were significantly improved by using ArFTFSIadded electrolyte.This study provides an electrolyte additive strategy for Li anode realizing SEI protection and electrostatic repulsion simultaneously.
基金National Natural Science Foundation of China,Grant/Award Numbers:NSFC:51872106,NSFC:11874025Natural Science Foundation of Hubei Province,Grant/Award Number:NSFHB:2016CFB432。
文摘With the accelerating advancement of distributed sensors and portable electronic devices in the era of big data,harvesting energy from the surrounding environment to power electrical devices has become increasingly attractive.However,most mechanical energy harvesters often require high operating frequencies to function properly.Moreover,for practical applications,the survivability of devices in harsh operating environments is a vital issuewhich must be addressed.Besides,the single-stimulus responsiveness limits their further applications in complex external environments.Here,a pressure and moisture dual-responsive ionic diode consisting of two organohydrogels with opposite charges as an energy harvester is proposed.The organohydrogel ionic diode utilizes the migration of cations and anions to form the depletion zone and followed by an enhancement of the built-in potential along the depletion zone as a result of mechanical stress or humidity,converting ultralow-frequency mechanical energy or moisture energy into electrical energy.Meanwhile,this mechanism is further confirmed by the finite element analysis.With the increased rectification ratio due to the introduction of MXene,the ionic diode exhibits a relatively large output current(∼10.10μA cm^(−2))and power density(∼0.10μW cm^(−2))at a mechanical pressure of 0.01 Hz,outperforming most currently available mechanical energy harvesters.More impressively,the incorporation of ethylene glycol provides the hydrogel ionic diode with excellent temperature tolerance and long-term environmental stability.The organohydrogel ionic diode can also be applied as a moisture-driven power generator and self-powered humidity sensor.This study presents promising prospects for the efficient collection of renewable and sustainable energy and the practical application of hydrogel-based energy harvesters in extreme environments.
基金This work was supported by the Science and Technology Planning Project of Fujian Province(2021J01151)CAS Key Laboratory of Design and Assembly of Functional Nanostructures(2013DP173231)+1 种基金the Award Program for Fujian Minjiang Scholar Professorship(2021)the Start-up Funding from FJNU。
文摘Graphene coating is commonly used to improve the performance of electrode materials,while its steric hindrance effect hampers fast ion transport with compromised rate capability.Herein,a unique single-walled carbon nanotubes(SWNTs)coating layer,as an alternative to graphene,has been developed to improve the battery behavior of iron-based anodes.Benefiting from the structure merits of mesoporous SWNTs layer for fast electron/ion transport and hollow Fe_(3)O_(4) for volume accommodation,as-prepared Fe_(3)O_(4)@SWNTs exhibited excellent lithium storage performance.It delivers a high capacity,excellent rate capability,and long lifespan with capacities of 582 mA·h·g^(-1) at 5 A·g^(-1) and 408 mA·h·g^(-1) at 8 A·g^(-1) remained after 1000 cycles.Such performance is better than graphene-coated Fe_(3)O_(4) and other SWNT-Fe_(3)O_(4) architectures.Besides,SWNTs coating is also used to improve the sodium and potassium storage performance of FeSe_(2).The kinetics analysis and ex-situ experiment further reveal the effect of SWNTs coating for fast electron/ion transfer kinetics and good structure stability,thus leading to the superior performance of SWNTs-coated composites.