In order to achieve better Na storage performance, most layered oxide positive electrode materials contain toxic and expensive transition metals Ni and/or Co, which are also widely used for lithium-ion batteries. Here...In order to achieve better Na storage performance, most layered oxide positive electrode materials contain toxic and expensive transition metals Ni and/or Co, which are also widely used for lithium-ion batteries. Here we report a new quaternary layered oxide consisting of Cu, Fe, Mn, and Ti transition metals with O3-type oxygen stacking as a positive electrode for room-temperature sodium-ion batteries. The material can be simply prepared by a high-temperature solidstate reaction route and delivers a reversible capacity of 94 m Ah/g with an average storage voltage of 3.2 V. This paves the way for cheaper and non-toxic batteries with high Na storage performance.展开更多
Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, ...Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, so it is necessary to realize fast Mg2+ transport in the host in addition to other requirements as practical cathode materials for magnesium batteries. Positive electrode materials based on inorganic transition-metal oxides, sulfides, and borides are the only ones used up to now to insert magnesium ions. In this paper, the available results of research on materials suitable as possible, for secondary magnesium batteries, are reviewed.展开更多
In the present paper, multi-walled carbon nanotubes（MWCNTs） are successfully assembled on graphite felt（GF） using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the b...In the present paper, multi-walled carbon nanotubes（MWCNTs） are successfully assembled on graphite felt（GF） using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the binder because it is essentially carbon materials as well as CNTs and GF which has a natural tendency to achieve high bonding strength and low contact resistance. The MWCNTs/GF electrode is demonstrated to increase surface area, reduce polarization, lower charge transfer resistance and improve energy conversion efficiency comparing with GF. This excellent electrochemical performance is mainly ascribed to the high electro-catalytic activity of MWCNTs and increasing surface area.展开更多
The reactivity between charged Li(Li_(0.115)Mn_(0.529)Ni_(0.339)Al_(0.017))O_(2)(Li-rich),single crystal Li(Ni_(0.8)Mn_(0.1)Co_(0.1))O_(2)(SC-NMC811),LiFePO_(4)(LFP) and LiMn_(0.8)Fe_(0.2)PO_(4)(LMFP) positive electro...The reactivity between charged Li(Li_(0.115)Mn_(0.529)Ni_(0.339)Al_(0.017))O_(2)(Li-rich),single crystal Li(Ni_(0.8)Mn_(0.1)Co_(0.1))O_(2)(SC-NMC811),LiFePO_(4)(LFP) and LiMn_(0.8)Fe_(0.2)PO_(4)(LMFP) positive electrodes at different states of charge(SOCs) and traditional carbonate-based electrolyte at elevated temperatures is systematically studied using accelerating rate calorimetry(ARC).The results show that the SOC greatly affects the thermal stability of the Li-rich and SC-NMC811 when traditional carbonate-based electrolyte is used.Although an increase in the SOC increases the energy density of lithium-ion cells,it also increases the reactivity between charged Li-rich and SC-NMC811 samples with electrolyte at elevated temperatures.In comparison with SC-NMC811,the Li-rich samples are much more stable at elevated temperatures,and the latter have higher specific capacity.SC-NMC811 samples are less reactive than traditional polycrystalline NMC811.Both LFP and LMFP samples show excellent thermal stability at elevated temperatures.The substitution of Fe by Mn in the olivine series positive materials does not impact the reactivity with electrolyte.展开更多
To achieve stable positive electrode for promoting the overall electrochemical performance of Al batteries(ABs),here novel cobalt boride(CoB)nanoclusters are synthesized to construct composite electrodes with few-laye...To achieve stable positive electrode for promoting the overall electrochemical performance of Al batteries(ABs),here novel cobalt boride(CoB)nanoclusters are synthesized to construct composite electrodes with few-layer graphene(FLG).Due to the presence of amorphous channels in the employed CoB nanoclusters,the ABs with FLG/CoB composite positive electrodes exhibit high rate.capability and both mechanical and electrochemical stability in the ABs.With assistance of in situ scanning electron microscopy(SEM),the observation results suggest that the positive electrode of CoB nanoclusters holds almost ignorable volume variation upon electrochemical processes,which substantially alleviates the massive electrode expansion induced by the anion intercalation in the composite positive electrode.Interestingly,the composite positive electrodes provide stable reversible energy storage capability within a broadened temperature range(-30-60℃),promising a novel strategy to design advanced ABs positive electrodes with enhanced overall energy storage performance.展开更多
In a steady-state plasma,the loss rate of plasma particles to the chamber wall and surfaces in contact with plasma is balanced by the ionization rate of background neutrals in the hot-filament discharges.The balance b...In a steady-state plasma,the loss rate of plasma particles to the chamber wall and surfaces in contact with plasma is balanced by the ionization rate of background neutrals in the hot-filament discharges.The balance between the loss rate and ionization rate of plasma particles(electrons and ions)maintains quasi-neutrality of the bulk plasma.In the presence of an external perturbation,it tries to retain its quasi-neutrality condition.In this work,we studied how the properties of bulk plasma are affected by an external DC potential perturbation.An auxiliary biased metal disk electrode was used to introduce a potential perturbation to the plasma medium.A single Langmuir probe and an emissive probe,placed in the line of the discharge axis,were used for the characterization of the bulk plasma.It is observed that only positive bias to the auxiliary metal disk increases the plasma potential,electron temperature,and plasma density but these plasma parameters remain unaltered when the disk is biased with a negative potential with respect to plasma potential.The observed plasma parameters for two different-sized,positively as well as negatively biased,metal disks are compared and found inconsistent with the existing theoretical model at large positive bias voltages.The role of the primary energetic electrons population in determining the plasma parameters is discussed.The experimentally observed results are qualitatively explained on the basis of electrostatic confinement arising due to the loss of electrons to a biased metal disk electrode.展开更多
Low specific capacitances and/or limited working potential(≤4.5 V).of the prevalent carbon-based positive electrodes as the inborn bottleneck seriously hinder practical advancement of lithium-ion capacitors.Thus,brea...Low specific capacitances and/or limited working potential(≤4.5 V).of the prevalent carbon-based positive electrodes as the inborn bottleneck seriously hinder practical advancement of lithium-ion capacitors.Thus,breakthroughs in enhancement of both specific capacitances and upper cutoff potentials are enormously significant for high-energy density lithium-ion capacitors.Herein,we first meticulously design and scalably fabricate a commercializable fluorine-doped porous carbon material with competitive tap density,large active surface,appropriate aperture distribution,and promoted affinity with the electrolyte,rendering its abundant electroactive inter-/surface and rapid PF_(6)^(-)transport.Theoretical calculations authenticate that fluorine-doped porous carbon possesses lower PF_(6)^(-)adsorption energy and stronger interaction with PF_(6)^(-).Thanks to the remarkable structural/compositional superiority,when served as a positive electrode toward lithium-ion capacitors,the commercial-level fluorine-doped porous carbon showcases the record-breaking electrochemical properties within a wider working window of 2.5-5.0 V(vs Li/Li^(+))in terms of high-rate specific capacitances and long-duration stability,much superior to commercial activated carbon.More significantly,the 4.5 V-class graphite//fluorine-doped porous carbon lithium-ion capacitors are first constructed and manifest competitive electrochemical behaviors with long-cycle life,modest polarization,and large energy density.Our work provides a commendable positive paradigm and contributes a major step forward in next-generation lithium-ion capacitors and even other high-energy density metal-ion capacitors.展开更多
Aluminum batteries are attractive in electrochemical energy storage due to high energy density and lowcost aluminum,while the energy density is limited for the lack of favorable positive electrode materials to match a...Aluminum batteries are attractive in electrochemical energy storage due to high energy density and lowcost aluminum,while the energy density is limited for the lack of favorable positive electrode materials to match aluminum negative electrodes.Tellurium positive electrode is intrinsically electrically conductive among chalcogen and holds high theoretical specific capacity(1260.27 mAh g^(-1)) and discharge voltage plateau(~1,5 V).However,the chemical and electrochemical dissolution of Te active materials results in the low material utilization and poor cycling stability.To enhance the electrochemical performance,herein a nitrogen doped porous carbon(N-PC) is derived from zeolite imidazolate framework(ZIF-67)as an effective tellurium host to suppress the undesired shuttle effect.In order to inhibit the volume expansion of N-PC during the charge/discharge process,the reduced graphene oxide(rGO) nanosheets are introduced to form a stable host materials(N-PC-rGO) for stabilizing Te.The physical encapsulation and chemical confinement to soluble tellurium species are achieved.N-PC-rGO-Te positive electrode exhibits an improved initial specific capacity and long-term cycling performance at a current density of 500 mA g^(-1)(initial specific capacity:935.5 mAh g^(-1);after 150 cycles:467.5 mAh g^(-1)), highlighting a promising design strategy for inhibiting chemical and electrochemical dissolution of Te.展开更多
The effect of operating conditions on the aluminium content of Ni-Al alloy deposit and the catalytic function of NaF on electrodeposition in the nonaqueous solution containing aluminium are investigated.The results in...The effect of operating conditions on the aluminium content of Ni-Al alloy deposit and the catalytic function of NaF on electrodeposition in the nonaqueous solution containing aluminium are investigated.The results indicate that the plated aluminuim content will be increased with the rise of current density in a given range.When the current density is 2.5A/dm 2,nickle aluminium alloy containing 13.1 wt% aluminium will be deposited.The plated aluminium content will be increased by 2wt% as 0.1mol/L NaF is added to the bath.展开更多
The emerging area of halide solid electrolytes has garnered significant interest due to its superior ionic conductivity,broad electrochemical stability range,and strong compatibility with positive electrode materials....The emerging area of halide solid electrolytes has garnered significant interest due to its superior ionic conductivity,broad electrochemical stability range,and strong compatibility with positive electrode materials.In recent times,there has been a continuous emergence of diverse halide systems.This study provides a comprehensive review of the synthesis strategies classification schemes,structural attributes,ion transport mechanisms,and modified means of halides.Notably,the paper delves into a detailed analysis of the structural details and ion conduction mechanisms of several representative halides.Furthermore,this review also examines the intrinsic connection between the recently discovered oxyhalides and halides and figures out the primary obstacles and prospective directions for advancement through a thorough review and analysis.展开更多
Aluminum metal is a promising negative electrode material for next generation rechargable batteries while the developed positive electrode materials of current aluminum batteries still have diffculty in meeting the de...Aluminum metal is a promising negative electrode material for next generation rechargable batteries while the developed positive electrode materials of current aluminum batteries still have diffculty in meeting the demands for high energy density.With a higher electrical conductivity than that of sulfur and selenium in chalcogen-based positive electrode materials,tellurium with high theoretical specific capacity(1260 mA h g^(−1))still suffers from severe capacity loss induced by the chemical and electrochemical process in the Lewis acid electrolyte.For massively promoting the utilization of active materials and rechargeability at both positive and negative electrodes,a simple strategy is demonstrated to construct tellurium–aluminum batteries(ATBs)using acetylene black/polyvinylidenefluoride modified separators,and the assembled ATB delivers a discharge capacity of∼1120 mA h g^(−1)(at 0.5 A g^(−1))and a considerably promoted capacity retention of 400 mA h g^(−1)after 300 cycles(at 1.0 A g^(−1)).Such a simple approach offers a low-cost and high-effciency strategy to develop advanced aluminium batteries with high capacity and energy density.展开更多
Designing multifunctional and core-shell-like architectures has attracted significant research interest for the enhancement of energy density in supercapatteries owing to their synergistic features of an efficient acc...Designing multifunctional and core-shell-like architectures has attracted significant research interest for the enhancement of energy density in supercapatteries owing to their synergistic features of an efficient accessibility of ions and high electrochemical activity.In the present work,we facilely synthesized a nickel hydroxide nanolayer-decorated cuprous oxide custard apple-like structure(Ni(OH)_(2)NL@Cu_(2)O CAS)to form a core-shell-like nanoarchitecture for use as an effective positive electrode in supercapatteries.展开更多
Hierarchical ZnCo_(2)O_(4)@MnO_(2)core–shell nanosheet arrays were successfully synthesized on Ni foam via a facile hydrothermal method followed by a calcination process.The fabricated ZnCo_(2)O_(4)@MnO_(2)electrode ...Hierarchical ZnCo_(2)O_(4)@MnO_(2)core–shell nanosheet arrays were successfully synthesized on Ni foam via a facile hydrothermal method followed by a calcination process.The fabricated ZnCo_(2)O_(4)@MnO_(2)electrode exhibited a specific capacitance as high as 2170.00 F g^(−1)(2.60 F cm^(−2))at a current density of 3 mA cm^(−2)in a 1 M KOH solution.Furthermore,an all-solid-state asymmetric supercapacitor(ASC)device fabricated with the as-prepared ZnCo_(2)O_(4)@MnO_(2)as the positive electrode and activated carbon(AC)as the negative electrode in the PVA/KOH gel electrolyte achieved a high energy density of 29.41 W h kg^(−1)at a power density of 628.42 W kg^(−1)and retained 95.3%of its initial capacitance after 3000 cycles at a high current density of 10 mA cm^(−2).With the smart design and remarkable electrochemical properties,the hierarchical ZnCo_(2)O_(4)@MnO_(2)core–shell nanosheet arrays on Ni foam demonstrated great potential for further applications in the energy storage field.展开更多
In this work,a template-assisted method was used to develop novel Ni_(2)P@PANI hollow nanotubes as a positive electrode material for supercapacitors using prepared polyaniline (PANI) nanotubes as precursors,and their ...In this work,a template-assisted method was used to develop novel Ni_(2)P@PANI hollow nanotubes as a positive electrode material for supercapacitors using prepared polyaniline (PANI) nanotubes as precursors,and their electrochemical behavior was studied. The results revealed that the Ni_(2)P@PANI nanotube electrode exhibited an average high specific capacity of 866 C g^(-1) at 2 A g^(-1). The experimental data were combined with density functional theory (DFT) calculations to reveal that the strong interaction between PANI and Ni_(2)P may lead to the formation of novel bonds at their interface and promote the redistribution of charges within the electrode,improving the capacitive properties. The combination of PANI and Ni_(2)P facilitated the adsorption and desorption of OH^(-),resulting in a rapid Faraday redox reaction at the electrodes. Additionally,a unique Fe_(2)O_(3)@PNCT hollow nanotube was fabricated as the negative electrode with the same PANI nanotube precursor. Thus,a “two-in-one” strategy was implemented. The assembled quasi-solid-state asymmetric supercapacitor exhibited a high energy density of 60.6 W h kg^(-1) at a power density of 852.3 W kg^(-1) and a high-capacity retention rate of 79.8% after 10 000 cycles.展开更多
Recently,although great efforts have been committed to enhance the electrochemical performance of supercapacitors(SCs),these devices are still unable to meet our expectations on account of limited working voltage,insu...Recently,although great efforts have been committed to enhance the electrochemical performance of supercapacitors(SCs),these devices are still unable to meet our expectations on account of limited working voltage,insufficient cycle life,low mechanical flexibility,and high cost.In this work,we have successfully synthesized several Mn_(3)[Co(CN)_(6)]_(2)·nH_(2)O nanocrystals by a mild precipitation method at room temperature.These Mn_(3)[Co(CN)_(6)]_(2)·nH_(2)O nanocrystals,as a novel kind of positive electrode materials,are firstly applied in flexible solid-state electrochemical energy storage devices.The best one of the as-assembled devices based on the as-prepared Mn_(3)[Co(CN)_(6)]_(2)·nH_(2)O nanocrystals shows high electrochemical performance activity,which offers the highest volumetric energy density of 4.69 mW h cm^(-3)at 1.0 mA cm^(-2)and exhibits the largest power density of 177.1 mW cm^(-3)at 20.0 mA cm^(-2).Remarkably,the device displayed wonderful mechanical flexibility as the bending angle range from 0°to 180°.Moreover,the device demonstrated little capacitance change over 7000 cycles at 1.0 mA cm^(-2),and exhibited a great cycling stability with 96.1%capacitance retention.展开更多
Energy storage systems are considered one of the key components for the large-scale utilization of renewable energy,which usually has an intermittent nature for production.In this case,vanadium redox flow batteries(VR...Energy storage systems are considered one of the key components for the large-scale utilization of renewable energy,which usually has an intermittent nature for production.In this case,vanadium redox flow batteries(VRFBs)have emerged as one of the most promising electrochemical energy storage systems for large-scale application,attracting significant attention in recent years.To achieve a high efficiency in VRFBs,the polymer electrolyte membrane between the positive and negative electrodes is expected to effectively transfer protons for internal circuits,and also prevent cross-over of the catholyte and anolyte.However,the high cost of membrane materials is currently a crucial factor restricting the large-scale application of VRFBs.In this review,key aspects related to the polymer electrolyte membranes in VRFBs are summarized,including their functional requirements,characterization methods,transport mechanisms,and classification.According to its classification,the latest research progress on the polymer electrolyte membrane in VRFBs is discussed in each section.Finally,the research directions and development of next-generation membrane materials for VRFBs are proposed,aiming to present a future perspective of this component in full batteries and inspire the ongoing efforts for building high-efficiency VRFBs in the power grid.展开更多
Structural battery composites are multifunctional materials capable of storing electrochemical energy and carry mechanical load at the same time.In this study,we focus on the laminated structural battery design develo...Structural battery composites are multifunctional materials capable of storing electrochemical energy and carry mechanical load at the same time.In this study,we focus on the laminated structural battery design developed by Asp and co-workers,which utilises multifunctional carbon fibres as both active material and mechanical reinforcement in the negative electrode.The positive electrode consists of active lithium iron phosphate particles adhered to an aluminium foil.Building upon previous research,we develop a fully coupled numerical multiphysics model to simulate the charge–discharge processes of the structural battery full cell.The model includes non-linear reaction kinetics,pertinent to the Butler–Volmer relation.Furthermore,we employ a simplified continuum representation of the porous positive electrode,enabling simulations at the battery cell level.Available experimental data for material parameters is utilised when possible,while the remaining parameters are obtained from calibration against experimental charge–discharge voltage profiles at two different rates.Results show that the presented model captures the general trend of the experimental voltage profiles for a range of charge rates.Through this work,we aim to provide insights for future structural battery design efforts.展开更多
Lithium-ion battery(LIB)is currently the most promising energy storage system[1],but which are constrained owing to the limited energy density[2].By overcoming the conventional constraint of a negative-to-positive ele...Lithium-ion battery(LIB)is currently the most promising energy storage system[1],but which are constrained owing to the limited energy density[2].By overcoming the conventional constraint of a negative-to-positive electrode capacity ratio(N/P)greater than 1(Fig.S1 online),the energy density of LIBs could be significantly enhanced.Nevertheless,lithium metal plating on graphite is widely recognized as a primary cause of capacity degradation in LIBs[3].Although initial attempts have been made to address this issue,such as electrolyte optimization[4,5]and graphite modification[6,7],LIBs with an N/P ratio less than 1 are solely underestimated and merely regarded as a simplistic amalgamation of lithium metal batteries and LIBs.展开更多
The Ni-rich Li[Ni0.6Co0.2Mn0.2]O2 surface has been modified with H3PO4. After coating at 80 ℃, the products were heated further at a moderate temperature of 500 ℃ in air, when the added H3PO4 transformed to Li3PO4 a...The Ni-rich Li[Ni0.6Co0.2Mn0.2]O2 surface has been modified with H3PO4. After coating at 80 ℃, the products were heated further at a moderate temperature of 500 ℃ in air, when the added H3PO4 transformed to Li3PO4 after reacting with residual LiOH and Li2CO3 on the surface. A thin and uniform smooth nanolayer （〈 10 nm） was observed on the surface of Li[Ni0.6Co0.2Mn0.2]O2 as confirmed by transmission electron microscopy （TEM）. Time-of-flight secondary ion mass spectroscopic （ToF-SIMS） data exhibit the presence of LIP＋, LiPO-, and Li2PO2＋ fragments, indicating the formation of the Li3PO4 coating layer on the surface of the Li[Ni0.6Co0.2Mn0.2]O2. As a result, the amounts of residual lithium compounds, such as LiOH and Li2CO3, are significantly reduced. As a consequence, the LigPO4-coated Li[Ni0.6Co0.2Mn0.2]O2 exhibits noticeable improvement in capacity retention and rate capability due to the reduction of residual LiOH and Li2CO3. Further investigation of the extensively cycled electrodes by X-ray diffraction （XRD）, TEM, and ToF-SIMS demonstrated that the LiBPO4 coating layers have multi-functions： Absorption of water in the electrolyte that lowers the HF level, HF scavenging, and protection of the active materials from deleterious side reactions with the electrolyte during extensive cycling, enabling high capacity retention over 1,000 cycles.展开更多
Graphite as a positive electrode material of dual ion batteries(DIBs)has attracted tremendous attentions for its advantages including low lost,high working voltage and high energy density.However,very few literatures ...Graphite as a positive electrode material of dual ion batteries(DIBs)has attracted tremendous attentions for its advantages including low lost,high working voltage and high energy density.However,very few literatures regarding to the real-time observation of anion intercalation behavior and surface evolution of graphite in DIBs have been reported.Herein,we use in situ atomic force microscope(AFM)to directly observe the intercalation/de-intercalation processes of PF6^-in graphite in real time.First,by measuring the change in the distance between graphene layers during intercalation,we found that PF6^-intercalates in one of every three graphite layers and the intercalation speed is measured to be 2μm-min^-1.Second,graphite will wrinke and suffer structural damnages at high voltages,along with severe electrolyte decomposition on the surface.These findings provide useful information for further optimizing the capacity and the stability of graphite anode in DIBs.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51222210 and 11234013)the One Hundred Talent Project of the Chinese Academy of Sciences
文摘In order to achieve better Na storage performance, most layered oxide positive electrode materials contain toxic and expensive transition metals Ni and/or Co, which are also widely used for lithium-ion batteries. Here we report a new quaternary layered oxide consisting of Cu, Fe, Mn, and Ti transition metals with O3-type oxygen stacking as a positive electrode for room-temperature sodium-ion batteries. The material can be simply prepared by a high-temperature solidstate reaction route and delivers a reversible capacity of 94 m Ah/g with an average storage voltage of 3.2 V. This paves the way for cheaper and non-toxic batteries with high Na storage performance.
基金supported by the National Natural Science foundation of China(No.50081004,50271032)the Special Fund for Major State Basic Research of China(973 Project 2002 CB 211800)Nankai-Tianjin University Union Science Fund.
文摘Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, so it is necessary to realize fast Mg2+ transport in the host in addition to other requirements as practical cathode materials for magnesium batteries. Positive electrode materials based on inorganic transition-metal oxides, sulfides, and borides are the only ones used up to now to insert magnesium ions. In this paper, the available results of research on materials suitable as possible, for secondary magnesium batteries, are reviewed.
基金financial support of the National Natural Science Foundation of China (project no. 51504231, 51504232, 51774262 and 21325628)Open Project of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization (project no. CNMRCUKF1704)
文摘In the present paper, multi-walled carbon nanotubes（MWCNTs） are successfully assembled on graphite felt（GF） using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the binder because it is essentially carbon materials as well as CNTs and GF which has a natural tendency to achieve high bonding strength and low contact resistance. The MWCNTs/GF electrode is demonstrated to increase surface area, reduce polarization, lower charge transfer resistance and improve energy conversion efficiency comparing with GF. This excellent electrochemical performance is mainly ascribed to the high electro-catalytic activity of MWCNTs and increasing surface area.
文摘The reactivity between charged Li(Li_(0.115)Mn_(0.529)Ni_(0.339)Al_(0.017))O_(2)(Li-rich),single crystal Li(Ni_(0.8)Mn_(0.1)Co_(0.1))O_(2)(SC-NMC811),LiFePO_(4)(LFP) and LiMn_(0.8)Fe_(0.2)PO_(4)(LMFP) positive electrodes at different states of charge(SOCs) and traditional carbonate-based electrolyte at elevated temperatures is systematically studied using accelerating rate calorimetry(ARC).The results show that the SOC greatly affects the thermal stability of the Li-rich and SC-NMC811 when traditional carbonate-based electrolyte is used.Although an increase in the SOC increases the energy density of lithium-ion cells,it also increases the reactivity between charged Li-rich and SC-NMC811 samples with electrolyte at elevated temperatures.In comparison with SC-NMC811,the Li-rich samples are much more stable at elevated temperatures,and the latter have higher specific capacity.SC-NMC811 samples are less reactive than traditional polycrystalline NMC811.Both LFP and LMFP samples show excellent thermal stability at elevated temperatures.The substitution of Fe by Mn in the olivine series positive materials does not impact the reactivity with electrolyte.
基金Financial support from the National Key R&D Program of China(No.2018YFB0104400)the National Natural Science Foundation of China(Nos.51725401,51874019 and 11672341)the Fundamental Research Funds for the Central Universities(No.FRFTP-17-002C2)is gratefully acknowledged.
文摘To achieve stable positive electrode for promoting the overall electrochemical performance of Al batteries(ABs),here novel cobalt boride(CoB)nanoclusters are synthesized to construct composite electrodes with few-layer graphene(FLG).Due to the presence of amorphous channels in the employed CoB nanoclusters,the ABs with FLG/CoB composite positive electrodes exhibit high rate.capability and both mechanical and electrochemical stability in the ABs.With assistance of in situ scanning electron microscopy(SEM),the observation results suggest that the positive electrode of CoB nanoclusters holds almost ignorable volume variation upon electrochemical processes,which substantially alleviates the massive electrode expansion induced by the anion intercalation in the composite positive electrode.Interestingly,the composite positive electrodes provide stable reversible energy storage capability within a broadened temperature range(-30-60℃),promising a novel strategy to design advanced ABs positive electrodes with enhanced overall energy storage performance.
文摘In a steady-state plasma,the loss rate of plasma particles to the chamber wall and surfaces in contact with plasma is balanced by the ionization rate of background neutrals in the hot-filament discharges.The balance between the loss rate and ionization rate of plasma particles(electrons and ions)maintains quasi-neutrality of the bulk plasma.In the presence of an external perturbation,it tries to retain its quasi-neutrality condition.In this work,we studied how the properties of bulk plasma are affected by an external DC potential perturbation.An auxiliary biased metal disk electrode was used to introduce a potential perturbation to the plasma medium.A single Langmuir probe and an emissive probe,placed in the line of the discharge axis,were used for the characterization of the bulk plasma.It is observed that only positive bias to the auxiliary metal disk increases the plasma potential,electron temperature,and plasma density but these plasma parameters remain unaltered when the disk is biased with a negative potential with respect to plasma potential.The observed plasma parameters for two different-sized,positively as well as negatively biased,metal disks are compared and found inconsistent with the existing theoretical model at large positive bias voltages.The role of the primary energetic electrons population in determining the plasma parameters is discussed.The experimentally observed results are qualitatively explained on the basis of electrostatic confinement arising due to the loss of electrons to a biased metal disk electrode.
基金support from the National Natural Science Foundation of China(Grant No.U22A20145,51904115,52072151,52171211,52102253,and 52271218)Jinan Independent Innovative Team(2020GXRC015)Major Program of Shandong Province Natural Science Foundation(ZR2023ZD43,ZR2021ZD05).
文摘Low specific capacitances and/or limited working potential(≤4.5 V).of the prevalent carbon-based positive electrodes as the inborn bottleneck seriously hinder practical advancement of lithium-ion capacitors.Thus,breakthroughs in enhancement of both specific capacitances and upper cutoff potentials are enormously significant for high-energy density lithium-ion capacitors.Herein,we first meticulously design and scalably fabricate a commercializable fluorine-doped porous carbon material with competitive tap density,large active surface,appropriate aperture distribution,and promoted affinity with the electrolyte,rendering its abundant electroactive inter-/surface and rapid PF_(6)^(-)transport.Theoretical calculations authenticate that fluorine-doped porous carbon possesses lower PF_(6)^(-)adsorption energy and stronger interaction with PF_(6)^(-).Thanks to the remarkable structural/compositional superiority,when served as a positive electrode toward lithium-ion capacitors,the commercial-level fluorine-doped porous carbon showcases the record-breaking electrochemical properties within a wider working window of 2.5-5.0 V(vs Li/Li^(+))in terms of high-rate specific capacitances and long-duration stability,much superior to commercial activated carbon.More significantly,the 4.5 V-class graphite//fluorine-doped porous carbon lithium-ion capacitors are first constructed and manifest competitive electrochemical behaviors with long-cycle life,modest polarization,and large energy density.Our work provides a commendable positive paradigm and contributes a major step forward in next-generation lithium-ion capacitors and even other high-energy density metal-ion capacitors.
基金supported by the National Natural Science Foundation of China(No.51725401 and 51874019)the Fundamental Research Funds for the Central Universities(FRF-TP-17-002C2)。
文摘Aluminum batteries are attractive in electrochemical energy storage due to high energy density and lowcost aluminum,while the energy density is limited for the lack of favorable positive electrode materials to match aluminum negative electrodes.Tellurium positive electrode is intrinsically electrically conductive among chalcogen and holds high theoretical specific capacity(1260.27 mAh g^(-1)) and discharge voltage plateau(~1,5 V).However,the chemical and electrochemical dissolution of Te active materials results in the low material utilization and poor cycling stability.To enhance the electrochemical performance,herein a nitrogen doped porous carbon(N-PC) is derived from zeolite imidazolate framework(ZIF-67)as an effective tellurium host to suppress the undesired shuttle effect.In order to inhibit the volume expansion of N-PC during the charge/discharge process,the reduced graphene oxide(rGO) nanosheets are introduced to form a stable host materials(N-PC-rGO) for stabilizing Te.The physical encapsulation and chemical confinement to soluble tellurium species are achieved.N-PC-rGO-Te positive electrode exhibits an improved initial specific capacity and long-term cycling performance at a current density of 500 mA g^(-1)(initial specific capacity:935.5 mAh g^(-1);after 150 cycles:467.5 mAh g^(-1)), highlighting a promising design strategy for inhibiting chemical and electrochemical dissolution of Te.
文摘The effect of operating conditions on the aluminium content of Ni-Al alloy deposit and the catalytic function of NaF on electrodeposition in the nonaqueous solution containing aluminium are investigated.The results indicate that the plated aluminuim content will be increased with the rise of current density in a given range.When the current density is 2.5A/dm 2,nickle aluminium alloy containing 13.1 wt% aluminium will be deposited.The plated aluminium content will be increased by 2wt% as 0.1mol/L NaF is added to the bath.
文摘The emerging area of halide solid electrolytes has garnered significant interest due to its superior ionic conductivity,broad electrochemical stability range,and strong compatibility with positive electrode materials.In recent times,there has been a continuous emergence of diverse halide systems.This study provides a comprehensive review of the synthesis strategies classification schemes,structural attributes,ion transport mechanisms,and modified means of halides.Notably,the paper delves into a detailed analysis of the structural details and ion conduction mechanisms of several representative halides.Furthermore,this review also examines the intrinsic connection between the recently discovered oxyhalides and halides and figures out the primary obstacles and prospective directions for advancement through a thorough review and analysis.
基金supported by the National Natural Science Foundation of China(No.51725401 and 51874019)the Fundamental Research Funds for the Central Universities(FRF-TP-17-002C2).
文摘Aluminum metal is a promising negative electrode material for next generation rechargable batteries while the developed positive electrode materials of current aluminum batteries still have diffculty in meeting the demands for high energy density.With a higher electrical conductivity than that of sulfur and selenium in chalcogen-based positive electrode materials,tellurium with high theoretical specific capacity(1260 mA h g^(−1))still suffers from severe capacity loss induced by the chemical and electrochemical process in the Lewis acid electrolyte.For massively promoting the utilization of active materials and rechargeability at both positive and negative electrodes,a simple strategy is demonstrated to construct tellurium–aluminum batteries(ATBs)using acetylene black/polyvinylidenefluoride modified separators,and the assembled ATB delivers a discharge capacity of∼1120 mA h g^(−1)(at 0.5 A g^(−1))and a considerably promoted capacity retention of 400 mA h g^(−1)after 300 cycles(at 1.0 A g^(−1)).Such a simple approach offers a low-cost and high-effciency strategy to develop advanced aluminium batteries with high capacity and energy density.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(No.2017R1A2B4011998 and No.2018R1A6A1A03025708).
文摘Designing multifunctional and core-shell-like architectures has attracted significant research interest for the enhancement of energy density in supercapatteries owing to their synergistic features of an efficient accessibility of ions and high electrochemical activity.In the present work,we facilely synthesized a nickel hydroxide nanolayer-decorated cuprous oxide custard apple-like structure(Ni(OH)_(2)NL@Cu_(2)O CAS)to form a core-shell-like nanoarchitecture for use as an effective positive electrode in supercapatteries.
基金supported by the National Natural Science Foundation of China(no.21271082 and 21731068).
文摘Hierarchical ZnCo_(2)O_(4)@MnO_(2)core–shell nanosheet arrays were successfully synthesized on Ni foam via a facile hydrothermal method followed by a calcination process.The fabricated ZnCo_(2)O_(4)@MnO_(2)electrode exhibited a specific capacitance as high as 2170.00 F g^(−1)(2.60 F cm^(−2))at a current density of 3 mA cm^(−2)in a 1 M KOH solution.Furthermore,an all-solid-state asymmetric supercapacitor(ASC)device fabricated with the as-prepared ZnCo_(2)O_(4)@MnO_(2)as the positive electrode and activated carbon(AC)as the negative electrode in the PVA/KOH gel electrolyte achieved a high energy density of 29.41 W h kg^(−1)at a power density of 628.42 W kg^(−1)and retained 95.3%of its initial capacitance after 3000 cycles at a high current density of 10 mA cm^(−2).With the smart design and remarkable electrochemical properties,the hierarchical ZnCo_(2)O_(4)@MnO_(2)core–shell nanosheet arrays on Ni foam demonstrated great potential for further applications in the energy storage field.
基金supported by the National Natural Science Foundation of China(no.22171101)the Open Fund Project of Key Laboratory of Electrochemical Energy Storage and Energy Conversion in Hainan Province of China(KFKT2019001).
文摘In this work,a template-assisted method was used to develop novel Ni_(2)P@PANI hollow nanotubes as a positive electrode material for supercapacitors using prepared polyaniline (PANI) nanotubes as precursors,and their electrochemical behavior was studied. The results revealed that the Ni_(2)P@PANI nanotube electrode exhibited an average high specific capacity of 866 C g^(-1) at 2 A g^(-1). The experimental data were combined with density functional theory (DFT) calculations to reveal that the strong interaction between PANI and Ni_(2)P may lead to the formation of novel bonds at their interface and promote the redistribution of charges within the electrode,improving the capacitive properties. The combination of PANI and Ni_(2)P facilitated the adsorption and desorption of OH^(-),resulting in a rapid Faraday redox reaction at the electrodes. Additionally,a unique Fe_(2)O_(3)@PNCT hollow nanotube was fabricated as the negative electrode with the same PANI nanotube precursor. Thus,a “two-in-one” strategy was implemented. The assembled quasi-solid-state asymmetric supercapacitor exhibited a high energy density of 60.6 W h kg^(-1) at a power density of 852.3 W kg^(-1) and a high-capacity retention rate of 79.8% after 10 000 cycles.
基金National Key Basic Research Program of China(973 Program,2014CB648300)Program for New Century Excellent Talents in University(NCET-13-0645,NCET-13-0872)+8 种基金National Natural Science Foundation of China(21201010,21422402,21671170,20904024,51173081,61136003,61106036)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(14IRTSTHN004)Natural Science Foundation of Jiangsu Province(BK20140060,BK20130037,BM2012010)Specialized Research Fund for the Doctoral Program of Higher Education(20133223110008)Ministry of Education of China(IRT1148)Program for Graduate Students Research and Innovation of Jiangsu Province(CXZZ12-0454)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Six Talent Plan(2012XCL035,2015-XCL-030)Qing Lan Project of Jiangsu Province。
文摘Recently,although great efforts have been committed to enhance the electrochemical performance of supercapacitors(SCs),these devices are still unable to meet our expectations on account of limited working voltage,insufficient cycle life,low mechanical flexibility,and high cost.In this work,we have successfully synthesized several Mn_(3)[Co(CN)_(6)]_(2)·nH_(2)O nanocrystals by a mild precipitation method at room temperature.These Mn_(3)[Co(CN)_(6)]_(2)·nH_(2)O nanocrystals,as a novel kind of positive electrode materials,are firstly applied in flexible solid-state electrochemical energy storage devices.The best one of the as-assembled devices based on the as-prepared Mn_(3)[Co(CN)_(6)]_(2)·nH_(2)O nanocrystals shows high electrochemical performance activity,which offers the highest volumetric energy density of 4.69 mW h cm^(-3)at 1.0 mA cm^(-2)and exhibits the largest power density of 177.1 mW cm^(-3)at 20.0 mA cm^(-2).Remarkably,the device displayed wonderful mechanical flexibility as the bending angle range from 0°to 180°.Moreover,the device demonstrated little capacitance change over 7000 cycles at 1.0 mA cm^(-2),and exhibited a great cycling stability with 96.1%capacitance retention.
基金supported by National Natural Science Foundation of China(U21B2057)Chalmers Areas of Advance Materials Science and Energy and Batteries Sweden(BASE).
文摘Energy storage systems are considered one of the key components for the large-scale utilization of renewable energy,which usually has an intermittent nature for production.In this case,vanadium redox flow batteries(VRFBs)have emerged as one of the most promising electrochemical energy storage systems for large-scale application,attracting significant attention in recent years.To achieve a high efficiency in VRFBs,the polymer electrolyte membrane between the positive and negative electrodes is expected to effectively transfer protons for internal circuits,and also prevent cross-over of the catholyte and anolyte.However,the high cost of membrane materials is currently a crucial factor restricting the large-scale application of VRFBs.In this review,key aspects related to the polymer electrolyte membranes in VRFBs are summarized,including their functional requirements,characterization methods,transport mechanisms,and classification.According to its classification,the latest research progress on the polymer electrolyte membrane in VRFBs is discussed in each section.Finally,the research directions and development of next-generation membrane materials for VRFBs are proposed,aiming to present a future perspective of this component in full batteries and inspire the ongoing efforts for building high-efficiency VRFBs in the power grid.
基金funded by the USAF via the EOARD Award No.FA8655-21-1-7038ONR,USA,Award No.N62909-22-1-2037+1 种基金Swedish Research Council,grant number 2020-050572D TECHVINNOVA competence Center,grant number 2019-00068.
文摘Structural battery composites are multifunctional materials capable of storing electrochemical energy and carry mechanical load at the same time.In this study,we focus on the laminated structural battery design developed by Asp and co-workers,which utilises multifunctional carbon fibres as both active material and mechanical reinforcement in the negative electrode.The positive electrode consists of active lithium iron phosphate particles adhered to an aluminium foil.Building upon previous research,we develop a fully coupled numerical multiphysics model to simulate the charge–discharge processes of the structural battery full cell.The model includes non-linear reaction kinetics,pertinent to the Butler–Volmer relation.Furthermore,we employ a simplified continuum representation of the porous positive electrode,enabling simulations at the battery cell level.Available experimental data for material parameters is utilised when possible,while the remaining parameters are obtained from calibration against experimental charge–discharge voltage profiles at two different rates.Results show that the presented model captures the general trend of the experimental voltage profiles for a range of charge rates.Through this work,we aim to provide insights for future structural battery design efforts.
基金supported by the National Natural Science Foundation of China(22278308)Shenzhen Higher Education Institutions Stable Support Program(WDZC20220817104930002).
文摘Lithium-ion battery(LIB)is currently the most promising energy storage system[1],but which are constrained owing to the limited energy density[2].By overcoming the conventional constraint of a negative-to-positive electrode capacity ratio(N/P)greater than 1(Fig.S1 online),the energy density of LIBs could be significantly enhanced.Nevertheless,lithium metal plating on graphite is widely recognized as a primary cause of capacity degradation in LIBs[3].Although initial attempts have been made to address this issue,such as electrolyte optimization[4,5]and graphite modification[6,7],LIBs with an N/P ratio less than 1 are solely underestimated and merely regarded as a simplistic amalgamation of lithium metal batteries and LIBs.
文摘The Ni-rich Li[Ni0.6Co0.2Mn0.2]O2 surface has been modified with H3PO4. After coating at 80 ℃, the products were heated further at a moderate temperature of 500 ℃ in air, when the added H3PO4 transformed to Li3PO4 after reacting with residual LiOH and Li2CO3 on the surface. A thin and uniform smooth nanolayer （〈 10 nm） was observed on the surface of Li[Ni0.6Co0.2Mn0.2]O2 as confirmed by transmission electron microscopy （TEM）. Time-of-flight secondary ion mass spectroscopic （ToF-SIMS） data exhibit the presence of LIP＋, LiPO-, and Li2PO2＋ fragments, indicating the formation of the Li3PO4 coating layer on the surface of the Li[Ni0.6Co0.2Mn0.2]O2. As a result, the amounts of residual lithium compounds, such as LiOH and Li2CO3, are significantly reduced. As a consequence, the LigPO4-coated Li[Ni0.6Co0.2Mn0.2]O2 exhibits noticeable improvement in capacity retention and rate capability due to the reduction of residual LiOH and Li2CO3. Further investigation of the extensively cycled electrodes by X-ray diffraction （XRD）, TEM, and ToF-SIMS demonstrated that the LiBPO4 coating layers have multi-functions： Absorption of water in the electrolyte that lowers the HF level, HF scavenging, and protection of the active materials from deleterious side reactions with the electrolyte during extensive cycling, enabling high capacity retention over 1,000 cycles.
基金This research was financially supported by Soft Science Research Project of Guangdong Province(No.2017B030301013)the Shenzhen Science and Technology Research(Nos.CYJ20170818085823773 and ZDSYS201707281026184).
文摘Graphite as a positive electrode material of dual ion batteries(DIBs)has attracted tremendous attentions for its advantages including low lost,high working voltage and high energy density.However,very few literatures regarding to the real-time observation of anion intercalation behavior and surface evolution of graphite in DIBs have been reported.Herein,we use in situ atomic force microscope(AFM)to directly observe the intercalation/de-intercalation processes of PF6^-in graphite in real time.First,by measuring the change in the distance between graphene layers during intercalation,we found that PF6^-intercalates in one of every three graphite layers and the intercalation speed is measured to be 2μm-min^-1.Second,graphite will wrinke and suffer structural damnages at high voltages,along with severe electrolyte decomposition on the surface.These findings provide useful information for further optimizing the capacity and the stability of graphite anode in DIBs.
