High voltage is necessary for high energy lithium-ion batteries but difficult to achieve because of the highly deteriorated cyclability of the batteries.A novel strategy is developed to extend cyclability of a high vo...High voltage is necessary for high energy lithium-ion batteries but difficult to achieve because of the highly deteriorated cyclability of the batteries.A novel strategy is developed to extend cyclability of a high voltage lithium-ion battery,LiNi_(0.5)Mn_(1.5)O_(4)/Graphite(LNMO/Graphite)cell,which emphasizes a rational design of an electrolyte additive that can effectively construct protective interphases on anode and cathode and highly eliminate the effect of hydrogen fluoride(HF).5-Trifluoromethylpyridine-trime thyl lithium borate(LTFMP-TMB),is synthesized,featuring with multi-functionalities.Its anion TFMPTMB-tends to be enriched on cathode and can be preferentially oxidized yielding TMB and radical TFMP-.Both TMB and radical TFMP can combine HF and thus eliminate the detrimental effect of HF on cathode,while the TMB dragged on cathode thus takes a preferential oxidation and constructs a protective cathode interphase.On the other hand,LTFMP-TMB is preferentially reduced on anode and constructs a protective anode interphase.Consequently,a small amount of LTFMP-TMB(0.2%)in 1.0 M LiPF6in EC/DEC/EMC(3/2/5,wt%)results in a highly improved cyclability of LNMO/Graphite cell,with the capacity retention enhanced from 52%to 80%after 150 cycles at 0.5 C between 3.5 and 4.8 V.The as-developed strategy provides a model of designing electrolyte additives for improving cyclability of high voltage batteries.展开更多
The burgeoning growth in electric vehicles and portable energy storage systems necessitates advances in the energy density and cost-effectiveness of lithium-ion batteries(LIBs),areas where lithium-rich manganese-based...The burgeoning growth in electric vehicles and portable energy storage systems necessitates advances in the energy density and cost-effectiveness of lithium-ion batteries(LIBs),areas where lithium-rich manganese-based oxide(LLO)materials naturally stand out.Despite their inherent advantages,these materials encounter significant practical hurdles,including low initial Coulombic efficiency(ICE),diminished cycle/rate performance,and voltage fading during cycling,hindering their widespread adoption.In response,we introduce an ionic-electronic dual-conductive(IEDC)surface control strategy that integrates an electronically conductive graphene framework with an ionically conductive heteroepitaxial spinel Li_(4)Mn_(5)O_(12)layer.Prolonged electrochemical and structural analyses demonstrate that this IEDC heterostructure effectively minimizes polarization,mitigates structural distortion,and enhances electronic/ionic diffusion.Density functional theory calculations highlight an extensive Li^(+)percolation network and lower Li^(+)migration energies at the layered-spinel interface.The designed LLO cathode with IEDC interface engineering(LMOSG)exhibits improved ICE(82.9%at 0.1 C),elevated initial discharge capacity(296.7 mAh g^(-1)at 0.1 C),exceptional rate capability(176.5 mAh g^(-1)at 5 C),and outstanding cycle stability(73.7%retention at 5 C after 500 cycles).These findings and the novel dual-conductive surface architecture design offer promising directions for advancing highperformance electrode materials.展开更多
Aqueous rechargeable ammonium-ion batteries(AIBs)have drew considerable attention because of their capacity for high rates,low cost,and high safety.However,developing desired electrodes requiring stable structure in t...Aqueous rechargeable ammonium-ion batteries(AIBs)have drew considerable attention because of their capacity for high rates,low cost,and high safety.However,developing desired electrodes requiring stable structure in the aqueous fast ammoniation/de-ammoniation becomes urgent.Herein,an ammonium ion full battery using Cu_(3)[Fe(CN)_(6)]_(2)(CuHCF)acting to be a cathode and barium vanadate(BVO)acting to be an anode is described.Its excellent electrochemical behavior of Prussian blue analogs and the perfectly matched lattice structure of NH_(4)^(+)is expected.And the open structure of vanadium compounds satisfies the fast ammoniation/de-ammoniation of NH4+is also achieved.As a result of these synergistic effects,the BVO//CuHCF full cell retains 80.5 percent of its capacity following 1000 cycling.These achievements provide new ideas for developing low-cost and long-life AIBs.展开更多
Nickel-rich layered Li transition metal oxides are the most promising cathode materials for high-energydensity Li-ion batteries.However,they exhibit rapid capacity degradation induced by transition metal dissolution a...Nickel-rich layered Li transition metal oxides are the most promising cathode materials for high-energydensity Li-ion batteries.However,they exhibit rapid capacity degradation induced by transition metal dissolution and structural reconstruction,which are associated with hydrofluoric acid(HF)generation from lithium hexafluorophosphate decomposition.The potential for thermal runaway during the working process poses another challenge.Separators are promising components to alleviate the aforementioned obstacles.Herein,an ultrathin double-layered separator with a 10 lm polyimide(PI)basement and a 2 lm polyvinylidene difluoride(PVDF)coating layer is designed and fabricated by combining a nonsolvent induced phase inversion process and coating method.The PI skeleton provides good stability against potential thermal shrinkage,and the strong PI-PVDF bonding endows the composite separator with robust structural integrity;these characteristics jointly contribute to the extraordinary mechanical tolerance of the separator at elevated temperatures.Additionally,unique HF-scavenging effects are achieved with the formation of-CO…H-F hydrogen bonds for the abundant HF coordination sites provided by the imide ring;hence,the layered Ni-rich cathodes are protected from HF attack,which ultimately reduces transition metal dissolution and facilitates long-term cyclability of the Ni-rich cathodes.Li||NCM811 batteries(where“NCM”indicates LiNi_(x)Co_(y)Mn_(1-x-y)O_(2))with the proposed composite separator exhibit a 90.6%capacity retention after 400 cycles at room temperature and remain sustainable at 60℃with a 91.4%capacity retention after 200 cycles.By adopting a new perspective on separators,this study presents a feasible and promising strategy for suppressing capacity degradation and enabling the safe operation of Ni-rich cathode materials.展开更多
Here we demonstrate the fabrication, electrochemical performance and application of an asymmetric supercapacitor (AS) device constructed with ss-Ni(OH)(2)/MWCNTs as positive electrode and KOH activated honeycomb-like ...Here we demonstrate the fabrication, electrochemical performance and application of an asymmetric supercapacitor (AS) device constructed with ss-Ni(OH)(2)/MWCNTs as positive electrode and KOH activated honeycomb-like porous carbon (K-PC) derived from banana fibers as negative electrode. Initially, the electrochemical performance of hydrothermally synthesized ss-Ni(OH)(2)/MWCNTs nanocomposite and K-PC was studied in a three-electrode system using 1 M KOH. These materials exhibited a specific capacitance (Cs) of 1327 Fig and 324 F/g respectively at a scan rate of 10 mV/s. Further, the AS device i.e., ss-Ni(OH)(2)/MWCNTs// K-PC in 1 M KOH solution, demonstrated a Cs of 156 F/g at scan rate of 10 mV/s in a broad cell voltage of 0-2.2 V. The device demonstrated a good rate capability by maintaining a Cs of 59 F/g even at high current density (25 A/g). The device also offered high energy density of 63 Wh/kg with maximum power density of 5.2 kW/kg. The AS device exhibited excellent cycle life with 100% capacitance retention at 5000th cycle at a high current density of 25 A/g. Two AS devices connected in series were employed for powering a pair of LEDs of different colors and also a mini fan. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
As promising anode candidates for potassium-ion batteries(PIBs),antimony sulfide(Sb_(2)S_(3))possesses high specific capacity but suffers from massive volume expansion and sluggish kinetics due to the large K^(+)inser...As promising anode candidates for potassium-ion batteries(PIBs),antimony sulfide(Sb_(2)S_(3))possesses high specific capacity but suffers from massive volume expansion and sluggish kinetics due to the large K^(+)insertion,resulting in inferior cycling and rate performance.To address these challenges,a yolk-shell structured Sb_(2)S_(3)confined in N,S co-doped hollow carbon nanorod(YS-Sb_(2)S_(3)@NSC)working as a viable anode for PIBs is proposed.As directly verified by in situ transmission electron microscopy(TEM),the buffer space between the Sb_(2)S_(3)core and thin carbon shell can effectively accommodate the large expansion stress of Sb_(2)S_(3)without cracking the shell and the carbon shell can accelerate electron transport and K^(+)diffusion,which plays a significant role in reinforcing the structural stability and facilitating charge transfer.As a result,the YS-Sb_(2)S_(3)@NSC electrode delivers a high reversible K^(+)storage capacity of 594.58 m A h g^(-1)at 0.1 A g^(-1)and a long cycle life with a slight capacity degradation(0.01%per cycle)for 2000 cycles at 1 A g^(-1)while maintaining outstanding rate capability.Importantly,utilizing in in situ/ex situ microscopic and spectroscopic characterizations,the origins of performance enhancement and K^(+)storage mechanism of Sb_(2)S_(3)were clearly elucidated.This work provides valuable insights into the rational design of high-performance and durable transition metal sulfides-based anodes for PIBs.展开更多
Layered Li-rich Mn-based oxides are promising cathode materials for Li-ion batteries due to their high capacity and high operation voltage.However,their commercial applications are hindered by irreversible capacity lo...Layered Li-rich Mn-based oxides are promising cathode materials for Li-ion batteries due to their high capacity and high operation voltage.However,their commercial applications are hindered by irreversible capacity loss in the first charge-discharge process,voltage decay during cycling,inefficient cyclability and rate capability.Many attempts have been performed to solve such issues,including the mechanism study and strategies to improve the electrochemical performance.This article provides a brief review and future perspective on the main challenges of the high-capacity Li-rich Mn-based cathodes for Li-ion batteries.展开更多
Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and ...Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and the formation of unstable solid electrolyte interphases during cycling,leading to rapid capacity decay and short cycle life of lithium-ion batteries.When addressing such issues,binder plays key roles in obtaining good structural integrity of silicon anodes.Herein,we report a biopolymer composite binder composed of rigid poly(acrylic acid)(PAA)and flexible silk fibroin(SF)tailored for micro-sized silicon anodes.The PAA/SF binder shows robust gradient binding energy via chemical interactions between carboxyl and amide groups,which can effectively accommodate large volume change of silicon.This PAA/SF binder also shows much stronger adhesion force and improved binding towards high-surface/defective carbon additives,resulting in better electrochemical stability and higher coulombic efficiency,than conventional PAA binder.As such,micro-sized silicon/carbon anodes fabricated with novel PAA/SF binder exhibit much better cyclability(up to 500 cycles at 0.5 C)and enhanced rate capability compared with conventional PAA-based anodes.This work provides new insights into the design of functional binders for high-capacity electrodes suffering from large volume change for the development of nextgeneration lithium batteries.展开更多
New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh o...New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh operating conditions. Here we report on the synthesis of a unique ionogel electrolyte for abuse-tolerant lithium batteries. A hierarchically architected silica/polymer scaffold is designed and fabricated through a facile soft chemistry route, which is competent to confine ionic liquids with superior uptake ability (92.4 wt%). The monolithic ionogel exhibits high conductivity and thermal/mechanical stability, featuring high-temperature elastic modulus and dendrite-free lithium cycling. The Li/LiFePO_(4) pouch cells achieve outstanding cyclability at different temperatures up to 150 ℃, and can sustain cutting, crumpling, and even coupled thermal–mechanical abuses. Moreover, the solid-state lithium batteries with LiNi_(0.60)Co_(0.20)Mn_(0.20)O_(2), LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2), and Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) cathodes demonstrate excellent cycle performances at 60 ℃. These results indicate that the resilient and high-conductivity ionogel electrolyte is promising to realize high-performance lithium batteries with high energy density and safety.展开更多
Developing host materials with high specific surface area, good electron conductivity, and fast ion transportation channel is critical for high performance lithium-selenium(Li-Se) batteries. Herein, a series of three ...Developing host materials with high specific surface area, good electron conductivity, and fast ion transportation channel is critical for high performance lithium-selenium(Li-Se) batteries. Herein, a series of three dimensional ordered hierarchically porous carbon(3D OHPC) materials with micro/meso/macropores are designed and synthesized for Li-Se battery. The porous structure is tuned by following the concept of the generalized Murray’s law to facilitate the mass diffusion and reduce ion transport resistance.The optimized 3D Se/OHPC cathode exhibits a very high 2 nd discharge capacity of 651 m Ah/g and retains 361 m Ah/g after 200 cycles at 0.2 C. Even at a high current rate of 5 C, the battery still shows a discharge capacity as high as 155 m Ah/g. The improved electrochemical performance is attributed to the synergy effect of the interconnected and well-designed micro, meso and macroporosity while shortened ions diffusion pathways of such Murray materials accelerate its ionic and electronic conductivities leading to the enhanced electrochemical reaction. The diffusivity coefficient in Se/OHPC can reach a very high value of 1.3 × 10^(-11)cm^(2)/s, much higher than those in single pore size carbon hosts. Their effective volume expansion accommodation capability and reduced dissolution of polyselenides ensure the high stability of the battery. This work, for the first time, established the clear relationship between textural properties of cathode materials and their performance and demonstrates that the concept of the generalized Murray’s law can be used as efficient guidance for the rational design and synthesis of advanced hierarchically porous materials and the great potential of 3D OHPC materials as a practical high performance cathode material for Li-Se batteries.展开更多
The high-rate cyclability of Li-rich Mn-based oxide(LMO)is highly limited by the electrochemical polarization resulting from the slow kinetic of the Li2MnO3 phase.Herein,the Prussian blue(PB)coating layer with specifi...The high-rate cyclability of Li-rich Mn-based oxide(LMO)is highly limited by the electrochemical polarization resulting from the slow kinetic of the Li2MnO3 phase.Herein,the Prussian blue(PB)coating layer with specific redox potential is introduced as a functionalized interface to overcome the side effect and the escaping of O on the surface of LMO,especially its poor rate capability.In detail,the PB layer can restrict the large polarization of LMO by sharing overloaded current at a high rate due to the synchronous redox of PB and LMO.Consequently,an enhanced high rate performance with capacity retention of 87.8%over 300 cycles is obtained,which is superior to 50.5%of the pristine electrode.Such strategies on the high-rate cyclability of Li-rich Mn-based oxide compatible with good low-rate performances may attract great attention for pursuing durable performances.展开更多
The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1 wt% TMSB can dramati...The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1 wt% TMSB can dramatically reduce the capacity fading that occurs during cycling at room temperature (RT) and elevated temperature (60 degrees C). After 150 cycles at 1 C rate (1 C= 278 mAh/g), the capacity retention of Li/LiCo1/3Ni1/3Mn1/3O2 is up to near 72% in the electrolyte with TMSB added, while it is only about 35% in the baseline electrolyte. The electrochemical behaviors, the surface chemistry and structure of Li/LiCo1/3Ni1/3Mn1/3O2 cathode are characterized with charge/discharge test, linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), thermal gravimetric analyses (TGA), scanning electron microscope (SEM) and transmission electron microscopy (TEM). These analysis results reveal that the addition of TMSB is able to protectively modify the electrode CEI film in a manner that suppresses electrolyte decomposition and degradation of electrode surface structure, even though at both a higher voltage of 4.7 V and an elevated temperature of 60 degrees C. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
The technique of contractions and the known results in the study of cycles in 3-connected cubic graphs are applied to obtain the following result. Let G be a 3-connected cubic graph, X C V（G） with ｜X｜ = 16 and e ...The technique of contractions and the known results in the study of cycles in 3-connected cubic graphs are applied to obtain the following result. Let G be a 3-connected cubic graph, X C V（G） with ｜X｜ = 16 and e ∈ E（G）. Then either for every 8-subset A of X, A U {e} is cyclable or for some 14-subset A of X, A U {e} is cyelable.展开更多
Alloying-type anode materials are considered promising candidates for next-generation alkali-ion batteries.However,they face significant challenges owing to severe volume variations and sluggish kinetics,which hinder t...Alloying-type anode materials are considered promising candidates for next-generation alkali-ion batteries.However,they face significant challenges owing to severe volume variations and sluggish kinetics,which hinder their practical applications.To address these issues,we propose a universal synthetic strategy,which can realize the facile synthesis of various alloying-type anode materials composed of a porous carbon matrix with uniformly embedded nanoparticles(Sb,Bi,or Sn).Besides,we construct the interactions among active materials,electrolyte compositions,and the resulting interface chemistries.This understanding assists in establishing balanced kinetics and stability.As a result,the fabricated battery cells based on the above strategy demonstrate high reversible capacity(515.6 mAh g1),long cycle life(200 cycles),and excellent high-rate capability(at 5.0 C).Additionally,it shows improved thermal stability at 45 and 60C.Moreover,our alloying-type anodes exhibit significant potential for constructing a 450 Wh kg1 battery system.This proposed strategy could boost the development of alloying-type anode materials,aligning with the future demands for low-cost,high stability,high safety,wide-temperature,and fast-charging battery systems.展开更多
Sodium metal batteries are arousing extensive interest owing to their high energy density,low cost and wide resource.However,the practical development of sodium metal batteries is inherently plagued by the severe volu...Sodium metal batteries are arousing extensive interest owing to their high energy density,low cost and wide resource.However,the practical development of sodium metal batteries is inherently plagued by the severe volume expansion and the dendrite growth of sodium metal anode during long cycles under high current density.Herein,a simple electrospinning method is applied to construct the uniformly nitrogen-doped porous carbon fiber skeleton and used as three-dimensional(3D)current collector for sodium metal anode,which has high specific surface area(1,098 m^2/g)and strong binding to sodium metal.As a result,nitrogen-doped carbon fiber current collector shows a low sodium deposition overpotential and a highly stable cyclability for 3,500 h with a high coulombic effciency of 99.9%at 2 mA/cm^2 and 2 mAh/cm^2.Moreover,the full cells using carbon coated sodium vanadium phosphate as cathode and sodium pre-plated nitrogen-doped carbon fiber skeleton as hybrid anode can stably cycle for 300 times.These results illustrate an effective strategy to construct a 3D uniformly nitrogen-doped carbon skeleton based sodium metal hybrid anode without the formation of dendrites,which provide a prospect for further development and research of high performance sodium metal batteries.展开更多
The demands for better energy storage devices due to fast development of electric vehicles(EVs) have raised increasing attention on lithium ion batteries(LIBs) with high power and energy densities. In this paper, we p...The demands for better energy storage devices due to fast development of electric vehicles(EVs) have raised increasing attention on lithium ion batteries(LIBs) with high power and energy densities. In this paper, we provide an overview of recent progress in graphene-based electrode materials. Graphene with its great electrical conductivity and mechanical properties have apparently improved the performance of traditional electrode materials. The methods and electrochemical properties of advanced graphene composite as cathode and anode for LIBs are reviewed. Two novel kinds of graphene hybrid materials are specially highlighted: three-dimensional porous and flexible binder-free graphene-based materials. Challenges for LIBs and future research trend in the development of high-performance electrode materials are further discussed.展开更多
Composite Si@SiO_(x)/C anodes with high specific capacity are considered the most promising alternatives to graphite in industrial lithium-ion batteries.However,their cycling stability remains a limiting factor,which ...Composite Si@SiO_(x)/C anodes with high specific capacity are considered the most promising alternatives to graphite in industrial lithium-ion batteries.However,their cycling stability remains a limiting factor,which originates from the severe volume deformation of silicon-derived species.In this work,the cyclabilities of composite anodes are improved by unshackling the highly reversible lithium storage capabilities from the redundancy capacity of the anode materials.A selective LiF-induced lithiation strategy is proposed based on exploiting interface separation energy differences between LiF and the active materials.An interesting preferential redeposition of LiF is observed at the Si@SiO_(x) particles,which differentiates the otherwise similar lithiation potentials of LiC_(x) and Li_(15)Si_(4),thereby enabling lithium storage in graphite that was previously underused.The resulting full cell exhibits better rate and cycling performances without sacrificing specific capacity.In an ultra-high area capacity full cell(4.9 mA h cm^(-2)),the capacity retention increases markedly from 66.1% to 94.2% after 300 cycles.The selective lithiation strategy developed herein is feasible for practical industrial applications,and importantly,it requires no changes to the existing mature lithium-ion battery manufacturing process.This study offers a new approach for the development of silicon/graphite composite anodes with long cycling lifetimes.展开更多
Un doubtedly,there remai ns an urge nt prerequisite to achieve sign ifica nt adva nces in both the specific capacity and cyclability of Li-O2 batteries for their practical application.In this work,a series of unique t...Un doubtedly,there remai ns an urge nt prerequisite to achieve sign ifica nt adva nces in both the specific capacity and cyclability of Li-O2 batteries for their practical application.In this work,a series of unique three-dimensional(3D)α-MnO2/MWCNTs hybrids are successfully prepared using a facile lyophilization method and investigated as the cathode of Li-O2 batteries.Thereinto,cross-1 inkedα-MnO2/MWCNTs nano composites are first syn thesized via a modified chemical route.Results dem on strate that MnO2 nano rods in the nano composites have a length of 100-400 nm and a diameter ranging from 5 to 10 nm,and more attractively,the as-lyophilized 3D MnO2/MWCNTs hybrids is uniquely constructed with large amounts of interconnected macroporous channels.The U-O2 battery with the 3D macroporous hybrid cathode that has a mass percentage of 50%ofα-MnO2 delivers a high discharge specific capacity of 8,643 mAh·g^-1 at 100 mA·g^-1,and main tains over 90 cycles before the discharge voltage drops to 2.0 V un der a controlled specific capacity of 1,000 mAh·g^-1.It is observed that when being recharged,the product of toroidal Li2O2 particles disappears and electrode surfaces are well recovered,thus confirming a good reversibility.The excellent performanee of Li-O2 battery with the 3Dα-MnO2/MWCNTs macroporous hybrid cathode is ascribed to a syn ergistic com bination betwee n the unique macroporous architecture and highly efficient bi-fun ctionalα-MnO2/MWCNTs electrocatalyst.展开更多
There is no doubt that SiO_(x) and carbon composite is one of the promising anode materials for lithium-ion batteries owing to its high capacity and rational cycling stability.Herein,we report a sol-gel synthesis foll...There is no doubt that SiO_(x) and carbon composite is one of the promising anode materials for lithium-ion batteries owing to its high capacity and rational cycling stability.Herein,we report a sol-gel synthesis followed by molten salt carbonization route to fabricate graphene-like carbon nanosheet wrapped SiO_(x)/C submicrospheres(SiO_(x)/C@2D-C).The in-situ generated carbon nanosheets under molten salt condition can further improve the electroconductivity,restrain the volumetric expansion and guarantee the structural integrity of the electrode.As a result,the as-obtained SiO_(x)/C@2D-C delivers a discharge capacity of 559 mAh·g^(-1) at 0.5 A·g^(-1) after 200 cycles and 548 mAh·g^(-1) at 1.0 A·g^(-1) even after 1000 cycles.The full cell assembled with SiO_(x)/C@2D-C as anode and commercial LiFeP0_(4) as cathode can achieve an energy density of 200 Wh·kg^(-1) and maintain a capacity of 66.7% after 100 cycles with a working potential of 2.8 V.The approach is simple and cost effective,which is promising for mass production of SiO_(x)-based materials for high energy LIBs.展开更多
An environment-friendly,water-soluble,and cellulose based binder(lithium carboxymethyl cellulose,CMC-Li)was successfully synthesized by using Li+to replace Na+in the commercial sodium carboxymethyl cellulose(CMC-Na).L...An environment-friendly,water-soluble,and cellulose based binder(lithium carboxymethyl cellulose,CMC-Li)was successfully synthesized by using Li+to replace Na+in the commercial sodium carboxymethyl cellulose(CMC-Na).Li-O2 batteries based on the CMC-Li binder present enhanced discharge specific capacities(11151 mAh/g at 100 mA/g)and a superior cycling stability(100 cycles at 200 mA/g)compared with those based on the CMC-Na binder.The enhanced performance may originate from the electrochemical stability of the CMC-Li binder and the ion-conductive nature of CMC-Li,which promotes the diffusion of Li+in the cathode and consequently retards the increase of charge transfer resistance of the cathode during cycling.The results show that the water-soluble CMC-Li binder can be a green substitute for poly(vinylidene fluoride)(PVDF)binder based on organic solvent in the lithium oxygen batteries(LOBs).展开更多
基金supported by the National Natural Science Foundation of China(22179041)。
文摘High voltage is necessary for high energy lithium-ion batteries but difficult to achieve because of the highly deteriorated cyclability of the batteries.A novel strategy is developed to extend cyclability of a high voltage lithium-ion battery,LiNi_(0.5)Mn_(1.5)O_(4)/Graphite(LNMO/Graphite)cell,which emphasizes a rational design of an electrolyte additive that can effectively construct protective interphases on anode and cathode and highly eliminate the effect of hydrogen fluoride(HF).5-Trifluoromethylpyridine-trime thyl lithium borate(LTFMP-TMB),is synthesized,featuring with multi-functionalities.Its anion TFMPTMB-tends to be enriched on cathode and can be preferentially oxidized yielding TMB and radical TFMP-.Both TMB and radical TFMP can combine HF and thus eliminate the detrimental effect of HF on cathode,while the TMB dragged on cathode thus takes a preferential oxidation and constructs a protective cathode interphase.On the other hand,LTFMP-TMB is preferentially reduced on anode and constructs a protective anode interphase.Consequently,a small amount of LTFMP-TMB(0.2%)in 1.0 M LiPF6in EC/DEC/EMC(3/2/5,wt%)results in a highly improved cyclability of LNMO/Graphite cell,with the capacity retention enhanced from 52%to 80%after 150 cycles at 0.5 C between 3.5 and 4.8 V.The as-developed strategy provides a model of designing electrolyte additives for improving cyclability of high voltage batteries.
基金National Natural Science Foundation of China,Grant/Award Numbers:22179008,21875022Yibin“Jie Bang Gua Shuai”,Grant/Award Number:2022JB004+2 种基金Beijing Nova Program,Grant/Award Number:20230484241Postdoctoral Fellowship Program of CPSF,Grant/Award Number:GZB20230931Special Support of Chongqing Postdoctoral Research Project,Grant/Award Number:2023CQBSHTB2041。
文摘The burgeoning growth in electric vehicles and portable energy storage systems necessitates advances in the energy density and cost-effectiveness of lithium-ion batteries(LIBs),areas where lithium-rich manganese-based oxide(LLO)materials naturally stand out.Despite their inherent advantages,these materials encounter significant practical hurdles,including low initial Coulombic efficiency(ICE),diminished cycle/rate performance,and voltage fading during cycling,hindering their widespread adoption.In response,we introduce an ionic-electronic dual-conductive(IEDC)surface control strategy that integrates an electronically conductive graphene framework with an ionically conductive heteroepitaxial spinel Li_(4)Mn_(5)O_(12)layer.Prolonged electrochemical and structural analyses demonstrate that this IEDC heterostructure effectively minimizes polarization,mitigates structural distortion,and enhances electronic/ionic diffusion.Density functional theory calculations highlight an extensive Li^(+)percolation network and lower Li^(+)migration energies at the layered-spinel interface.The designed LLO cathode with IEDC interface engineering(LMOSG)exhibits improved ICE(82.9%at 0.1 C),elevated initial discharge capacity(296.7 mAh g^(-1)at 0.1 C),exceptional rate capability(176.5 mAh g^(-1)at 5 C),and outstanding cycle stability(73.7%retention at 5 C after 500 cycles).These findings and the novel dual-conductive surface architecture design offer promising directions for advancing highperformance electrode materials.
基金Joint Funds of the National Natural Science Foundation of China(No.U22A20140)the Independent Cultivation Program of Innovation Team of Ji'nan City(No.2019GXRC011)the Natural Science Foundation of Shandong Province,China(No.ZR2021MA073)。
文摘Aqueous rechargeable ammonium-ion batteries(AIBs)have drew considerable attention because of their capacity for high rates,low cost,and high safety.However,developing desired electrodes requiring stable structure in the aqueous fast ammoniation/de-ammoniation becomes urgent.Herein,an ammonium ion full battery using Cu_(3)[Fe(CN)_(6)]_(2)(CuHCF)acting to be a cathode and barium vanadate(BVO)acting to be an anode is described.Its excellent electrochemical behavior of Prussian blue analogs and the perfectly matched lattice structure of NH_(4)^(+)is expected.And the open structure of vanadium compounds satisfies the fast ammoniation/de-ammoniation of NH4+is also achieved.As a result of these synergistic effects,the BVO//CuHCF full cell retains 80.5 percent of its capacity following 1000 cycling.These achievements provide new ideas for developing low-cost and long-life AIBs.
基金supported by the Science Foundation of the National Key Laboratory of Science and Technology on Advanced Composites in Special Environments.This work was sponsored by the Natural Science Foundation of Chongqing,China(CSTC2021jcyjmsxmX10305,CSTB2022NSCQ-MSX0246,CSTB2022NSCQMSX0242,CSTB2022NSCQ-MSX1244,CSTB2022NSCQ-MSX0441,CSTB2022NSCQ-MSX1356,CSTB2022NSCQ-MSX1572,CSTB2022 NSCQ-MSX1583,CSTB2022NSCQMSX0487,CSTB2022TFII-OFX0034,and CSTB2023TIAD-KPX0010)the Chongqing Technology Innovation and Application Development Special Key Project(CSTB2023TIAD-KPX0010).
文摘Nickel-rich layered Li transition metal oxides are the most promising cathode materials for high-energydensity Li-ion batteries.However,they exhibit rapid capacity degradation induced by transition metal dissolution and structural reconstruction,which are associated with hydrofluoric acid(HF)generation from lithium hexafluorophosphate decomposition.The potential for thermal runaway during the working process poses another challenge.Separators are promising components to alleviate the aforementioned obstacles.Herein,an ultrathin double-layered separator with a 10 lm polyimide(PI)basement and a 2 lm polyvinylidene difluoride(PVDF)coating layer is designed and fabricated by combining a nonsolvent induced phase inversion process and coating method.The PI skeleton provides good stability against potential thermal shrinkage,and the strong PI-PVDF bonding endows the composite separator with robust structural integrity;these characteristics jointly contribute to the extraordinary mechanical tolerance of the separator at elevated temperatures.Additionally,unique HF-scavenging effects are achieved with the formation of-CO…H-F hydrogen bonds for the abundant HF coordination sites provided by the imide ring;hence,the layered Ni-rich cathodes are protected from HF attack,which ultimately reduces transition metal dissolution and facilitates long-term cyclability of the Ni-rich cathodes.Li||NCM811 batteries(where“NCM”indicates LiNi_(x)Co_(y)Mn_(1-x-y)O_(2))with the proposed composite separator exhibit a 90.6%capacity retention after 400 cycles at room temperature and remain sustainable at 60℃with a 91.4%capacity retention after 200 cycles.By adopting a new perspective on separators,this study presents a feasible and promising strategy for suppressing capacity degradation and enabling the safe operation of Ni-rich cathode materials.
基金supported by the Naval Research Board(NRB)Project Number:NRB-290/MAT/12-13
文摘Here we demonstrate the fabrication, electrochemical performance and application of an asymmetric supercapacitor (AS) device constructed with ss-Ni(OH)(2)/MWCNTs as positive electrode and KOH activated honeycomb-like porous carbon (K-PC) derived from banana fibers as negative electrode. Initially, the electrochemical performance of hydrothermally synthesized ss-Ni(OH)(2)/MWCNTs nanocomposite and K-PC was studied in a three-electrode system using 1 M KOH. These materials exhibited a specific capacitance (Cs) of 1327 Fig and 324 F/g respectively at a scan rate of 10 mV/s. Further, the AS device i.e., ss-Ni(OH)(2)/MWCNTs// K-PC in 1 M KOH solution, demonstrated a Cs of 156 F/g at scan rate of 10 mV/s in a broad cell voltage of 0-2.2 V. The device demonstrated a good rate capability by maintaining a Cs of 59 F/g even at high current density (25 A/g). The device also offered high energy density of 63 Wh/kg with maximum power density of 5.2 kW/kg. The AS device exhibited excellent cycle life with 100% capacitance retention at 5000th cycle at a high current density of 25 A/g. Two AS devices connected in series were employed for powering a pair of LEDs of different colors and also a mini fan. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金supported by the National Natural Science Foundation of China(Grants Nos.52072323 and 52122211)the"Double-First Class"Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen Universitythe State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Grant No.LAPS22005)。
文摘As promising anode candidates for potassium-ion batteries(PIBs),antimony sulfide(Sb_(2)S_(3))possesses high specific capacity but suffers from massive volume expansion and sluggish kinetics due to the large K^(+)insertion,resulting in inferior cycling and rate performance.To address these challenges,a yolk-shell structured Sb_(2)S_(3)confined in N,S co-doped hollow carbon nanorod(YS-Sb_(2)S_(3)@NSC)working as a viable anode for PIBs is proposed.As directly verified by in situ transmission electron microscopy(TEM),the buffer space between the Sb_(2)S_(3)core and thin carbon shell can effectively accommodate the large expansion stress of Sb_(2)S_(3)without cracking the shell and the carbon shell can accelerate electron transport and K^(+)diffusion,which plays a significant role in reinforcing the structural stability and facilitating charge transfer.As a result,the YS-Sb_(2)S_(3)@NSC electrode delivers a high reversible K^(+)storage capacity of 594.58 m A h g^(-1)at 0.1 A g^(-1)and a long cycle life with a slight capacity degradation(0.01%per cycle)for 2000 cycles at 1 A g^(-1)while maintaining outstanding rate capability.Importantly,utilizing in in situ/ex situ microscopic and spectroscopic characterizations,the origins of performance enhancement and K^(+)storage mechanism of Sb_(2)S_(3)were clearly elucidated.This work provides valuable insights into the rational design of high-performance and durable transition metal sulfides-based anodes for PIBs.
基金This work was supported by NSFC(21621091)National Key Research and Development of China(2016YFB0100202)+4 种基金Natural Science Foundation of Fujian Province(2015J01063)the support of National Materials Genome Project(2016YFB0700600)National Key R&D Program of China(2016YFB0700600)the Guangdong Innovation Team Project(No.2013N080)Shenzhen Science and Technology Research(Nos.JCYJ20151015162256516,JCYJ20150729111733470 and JCYJ20160226105838578)。
文摘Layered Li-rich Mn-based oxides are promising cathode materials for Li-ion batteries due to their high capacity and high operation voltage.However,their commercial applications are hindered by irreversible capacity loss in the first charge-discharge process,voltage decay during cycling,inefficient cyclability and rate capability.Many attempts have been performed to solve such issues,including the mechanism study and strategies to improve the electrochemical performance.This article provides a brief review and future perspective on the main challenges of the high-capacity Li-rich Mn-based cathodes for Li-ion batteries.
文摘Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and the formation of unstable solid electrolyte interphases during cycling,leading to rapid capacity decay and short cycle life of lithium-ion batteries.When addressing such issues,binder plays key roles in obtaining good structural integrity of silicon anodes.Herein,we report a biopolymer composite binder composed of rigid poly(acrylic acid)(PAA)and flexible silk fibroin(SF)tailored for micro-sized silicon anodes.The PAA/SF binder shows robust gradient binding energy via chemical interactions between carboxyl and amide groups,which can effectively accommodate large volume change of silicon.This PAA/SF binder also shows much stronger adhesion force and improved binding towards high-surface/defective carbon additives,resulting in better electrochemical stability and higher coulombic efficiency,than conventional PAA binder.As such,micro-sized silicon/carbon anodes fabricated with novel PAA/SF binder exhibit much better cyclability(up to 500 cycles at 0.5 C)and enhanced rate capability compared with conventional PAA-based anodes.This work provides new insights into the design of functional binders for high-capacity electrodes suffering from large volume change for the development of nextgeneration lithium batteries.
基金This work is supported by the National Natural Science Foundation of China(No.51972132.51772116 and 52002141)the Program for HUST Academic Frontier Youth Team(2016QYTD04).The authors thank the Analytical and Testing Center of HUST for DMA,TGA measurements,etc.
文摘New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh operating conditions. Here we report on the synthesis of a unique ionogel electrolyte for abuse-tolerant lithium batteries. A hierarchically architected silica/polymer scaffold is designed and fabricated through a facile soft chemistry route, which is competent to confine ionic liquids with superior uptake ability (92.4 wt%). The monolithic ionogel exhibits high conductivity and thermal/mechanical stability, featuring high-temperature elastic modulus and dendrite-free lithium cycling. The Li/LiFePO_(4) pouch cells achieve outstanding cyclability at different temperatures up to 150 ℃, and can sustain cutting, crumpling, and even coupled thermal–mechanical abuses. Moreover, the solid-state lithium batteries with LiNi_(0.60)Co_(0.20)Mn_(0.20)O_(2), LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2), and Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) cathodes demonstrate excellent cycle performances at 60 ℃. These results indicate that the resilient and high-conductivity ionogel electrolyte is promising to realize high-performance lithium batteries with high energy density and safety.
基金financial support from the China Scholarship Council (CSC) and a scholarship from the Laboratory of Inorganic Materials Chemistry,Universitéde Namur,Belgiumfinancially supported by the National Postdoctoral Program (Grant No. 2020M672782)+2 种基金the National Natural Science Foundation of China (Grant No. U1663225)the the Program of Introducing Talents of Discipline to Universities-National 111 Project from the Ministry of Science and Technology and the Ministry of Education of China (Grant No. B20002)the National Key R&D Program of China (Grant No. 2016YFA0202602)。
文摘Developing host materials with high specific surface area, good electron conductivity, and fast ion transportation channel is critical for high performance lithium-selenium(Li-Se) batteries. Herein, a series of three dimensional ordered hierarchically porous carbon(3D OHPC) materials with micro/meso/macropores are designed and synthesized for Li-Se battery. The porous structure is tuned by following the concept of the generalized Murray’s law to facilitate the mass diffusion and reduce ion transport resistance.The optimized 3D Se/OHPC cathode exhibits a very high 2 nd discharge capacity of 651 m Ah/g and retains 361 m Ah/g after 200 cycles at 0.2 C. Even at a high current rate of 5 C, the battery still shows a discharge capacity as high as 155 m Ah/g. The improved electrochemical performance is attributed to the synergy effect of the interconnected and well-designed micro, meso and macroporosity while shortened ions diffusion pathways of such Murray materials accelerate its ionic and electronic conductivities leading to the enhanced electrochemical reaction. The diffusivity coefficient in Se/OHPC can reach a very high value of 1.3 × 10^(-11)cm^(2)/s, much higher than those in single pore size carbon hosts. Their effective volume expansion accommodation capability and reduced dissolution of polyselenides ensure the high stability of the battery. This work, for the first time, established the clear relationship between textural properties of cathode materials and their performance and demonstrates that the concept of the generalized Murray’s law can be used as efficient guidance for the rational design and synthesis of advanced hierarchically porous materials and the great potential of 3D OHPC materials as a practical high performance cathode material for Li-Se batteries.
基金supported by the National Natural Science Foundation of China (51802261,52072298,and 52172228)the Natural Science Foundation of Shaanxi (2019GHJD-13 and 2020JC-41)+2 种基金the Natural Science Basic Research Plan in Shaanxi province of China (2019JLP-04)Xi'an Science and Technology Project of China (2019219714SYS012CG034)the foundation of National Key Laboratory (6142808200202),PR China.
文摘The high-rate cyclability of Li-rich Mn-based oxide(LMO)is highly limited by the electrochemical polarization resulting from the slow kinetic of the Li2MnO3 phase.Herein,the Prussian blue(PB)coating layer with specific redox potential is introduced as a functionalized interface to overcome the side effect and the escaping of O on the surface of LMO,especially its poor rate capability.In detail,the PB layer can restrict the large polarization of LMO by sharing overloaded current at a high rate due to the synchronous redox of PB and LMO.Consequently,an enhanced high rate performance with capacity retention of 87.8%over 300 cycles is obtained,which is superior to 50.5%of the pristine electrode.Such strategies on the high-rate cyclability of Li-rich Mn-based oxide compatible with good low-rate performances may attract great attention for pursuing durable performances.
文摘The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1 wt% TMSB can dramatically reduce the capacity fading that occurs during cycling at room temperature (RT) and elevated temperature (60 degrees C). After 150 cycles at 1 C rate (1 C= 278 mAh/g), the capacity retention of Li/LiCo1/3Ni1/3Mn1/3O2 is up to near 72% in the electrolyte with TMSB added, while it is only about 35% in the baseline electrolyte. The electrochemical behaviors, the surface chemistry and structure of Li/LiCo1/3Ni1/3Mn1/3O2 cathode are characterized with charge/discharge test, linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), thermal gravimetric analyses (TGA), scanning electron microscope (SEM) and transmission electron microscopy (TEM). These analysis results reveal that the addition of TMSB is able to protectively modify the electrode CEI film in a manner that suppresses electrolyte decomposition and degradation of electrode surface structure, even though at both a higher voltage of 4.7 V and an elevated temperature of 60 degrees C. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金Supported by the National Natural Science Foundation of China(Grant No.10971027)
文摘The technique of contractions and the known results in the study of cycles in 3-connected cubic graphs are applied to obtain the following result. Let G be a 3-connected cubic graph, X C V（G） with ｜X｜ = 16 and e ∈ E（G）. Then either for every 8-subset A of X, A U {e} is cyclable or for some 14-subset A of X, A U {e} is cyelable.
基金supported by the National Natural Science Foundation of China(52002094)Guangdong Basic and Applied Basic Research Foundation(2019A1515110756)+1 种基金Shenzhen Science and Technology Program(JCYJ20210324121411031,JSGG202108021253804014,RCBS 20210706092218040,GXWD20221030205923001,and GXWD20201230155427003-20200824103000001)State Key Laboratory of Precision Welding&Joining of Materials and Structures(Nos.24-Z-17,24-T-08).
文摘Alloying-type anode materials are considered promising candidates for next-generation alkali-ion batteries.However,they face significant challenges owing to severe volume variations and sluggish kinetics,which hinder their practical applications.To address these issues,we propose a universal synthetic strategy,which can realize the facile synthesis of various alloying-type anode materials composed of a porous carbon matrix with uniformly embedded nanoparticles(Sb,Bi,or Sn).Besides,we construct the interactions among active materials,electrolyte compositions,and the resulting interface chemistries.This understanding assists in establishing balanced kinetics and stability.As a result,the fabricated battery cells based on the above strategy demonstrate high reversible capacity(515.6 mAh g1),long cycle life(200 cycles),and excellent high-rate capability(at 5.0 C).Additionally,it shows improved thermal stability at 45 and 60C.Moreover,our alloying-type anodes exhibit significant potential for constructing a 450 Wh kg1 battery system.This proposed strategy could boost the development of alloying-type anode materials,aligning with the future demands for low-cost,high stability,high safety,wide-temperature,and fast-charging battery systems.
基金The authors gratefully acknowledge financial support from the Fundamental Research Funds for the Central Universities of China(No.20720190013)the Guangdong Basic and Applied Basic Research Foundation(Nos.2019A1515011070 and 2019B151502045)the National Natural Science Foundation of China(Nos.51972351 and 51802361).
文摘Sodium metal batteries are arousing extensive interest owing to their high energy density,low cost and wide resource.However,the practical development of sodium metal batteries is inherently plagued by the severe volume expansion and the dendrite growth of sodium metal anode during long cycles under high current density.Herein,a simple electrospinning method is applied to construct the uniformly nitrogen-doped porous carbon fiber skeleton and used as three-dimensional(3D)current collector for sodium metal anode,which has high specific surface area(1,098 m^2/g)and strong binding to sodium metal.As a result,nitrogen-doped carbon fiber current collector shows a low sodium deposition overpotential and a highly stable cyclability for 3,500 h with a high coulombic effciency of 99.9%at 2 mA/cm^2 and 2 mAh/cm^2.Moreover,the full cells using carbon coated sodium vanadium phosphate as cathode and sodium pre-plated nitrogen-doped carbon fiber skeleton as hybrid anode can stably cycle for 300 times.These results illustrate an effective strategy to construct a 3D uniformly nitrogen-doped carbon skeleton based sodium metal hybrid anode without the formation of dendrites,which provide a prospect for further development and research of high performance sodium metal batteries.
基金supported by the National Hi-Tech Research and Development Program of China("863"Project)(Grant No.2012CB932303)Shanghai Municipal Natural Science Foundation(Grant Nos.13ZR1463600&13XD1403900)
文摘The demands for better energy storage devices due to fast development of electric vehicles(EVs) have raised increasing attention on lithium ion batteries(LIBs) with high power and energy densities. In this paper, we provide an overview of recent progress in graphene-based electrode materials. Graphene with its great electrical conductivity and mechanical properties have apparently improved the performance of traditional electrode materials. The methods and electrochemical properties of advanced graphene composite as cathode and anode for LIBs are reviewed. Two novel kinds of graphene hybrid materials are specially highlighted: three-dimensional porous and flexible binder-free graphene-based materials. Challenges for LIBs and future research trend in the development of high-performance electrode materials are further discussed.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2020B090919005)the National Key R&D Program of China(2017YFE0127600)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010600)Taishan Scholars Program for Young Expert of Shandong Province(tsqn 202103145)the National Natural Science Foundation of China(22179135)the Finance Science and Technology Project of Hainan province(ZDKJ202014)。
文摘Composite Si@SiO_(x)/C anodes with high specific capacity are considered the most promising alternatives to graphite in industrial lithium-ion batteries.However,their cycling stability remains a limiting factor,which originates from the severe volume deformation of silicon-derived species.In this work,the cyclabilities of composite anodes are improved by unshackling the highly reversible lithium storage capabilities from the redundancy capacity of the anode materials.A selective LiF-induced lithiation strategy is proposed based on exploiting interface separation energy differences between LiF and the active materials.An interesting preferential redeposition of LiF is observed at the Si@SiO_(x) particles,which differentiates the otherwise similar lithiation potentials of LiC_(x) and Li_(15)Si_(4),thereby enabling lithium storage in graphite that was previously underused.The resulting full cell exhibits better rate and cycling performances without sacrificing specific capacity.In an ultra-high area capacity full cell(4.9 mA h cm^(-2)),the capacity retention increases markedly from 66.1% to 94.2% after 300 cycles.The selective lithiation strategy developed herein is feasible for practical industrial applications,and importantly,it requires no changes to the existing mature lithium-ion battery manufacturing process.This study offers a new approach for the development of silicon/graphite composite anodes with long cycling lifetimes.
基金the National Basic Research Program of China(973)(Nos.2014CB932300 and 2014CB932303)the National Key Research and Development Program of China(No.2016YFB0101201)the National Natural Science Foundation of China(Nos.21533005 and 21503134).
文摘Un doubtedly,there remai ns an urge nt prerequisite to achieve sign ifica nt adva nces in both the specific capacity and cyclability of Li-O2 batteries for their practical application.In this work,a series of unique three-dimensional(3D)α-MnO2/MWCNTs hybrids are successfully prepared using a facile lyophilization method and investigated as the cathode of Li-O2 batteries.Thereinto,cross-1 inkedα-MnO2/MWCNTs nano composites are first syn thesized via a modified chemical route.Results dem on strate that MnO2 nano rods in the nano composites have a length of 100-400 nm and a diameter ranging from 5 to 10 nm,and more attractively,the as-lyophilized 3D MnO2/MWCNTs hybrids is uniquely constructed with large amounts of interconnected macroporous channels.The U-O2 battery with the 3D macroporous hybrid cathode that has a mass percentage of 50%ofα-MnO2 delivers a high discharge specific capacity of 8,643 mAh·g^-1 at 100 mA·g^-1,and main tains over 90 cycles before the discharge voltage drops to 2.0 V un der a controlled specific capacity of 1,000 mAh·g^-1.It is observed that when being recharged,the product of toroidal Li2O2 particles disappears and electrode surfaces are well recovered,thus confirming a good reversibility.The excellent performanee of Li-O2 battery with the 3Dα-MnO2/MWCNTs macroporous hybrid cathode is ascribed to a syn ergistic com bination betwee n the unique macroporous architecture and highly efficient bi-fun ctionalα-MnO2/MWCNTs electrocatalyst.
基金the National Natural Science Foundation of China(Nos.21971145,21871164,U1764258)the Taishan Scholar Project Foundation of Shandong Province(No.ts20190908)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2019MB024)the Young Scholars Program of Shandong University(No.2017WUH15).
文摘There is no doubt that SiO_(x) and carbon composite is one of the promising anode materials for lithium-ion batteries owing to its high capacity and rational cycling stability.Herein,we report a sol-gel synthesis followed by molten salt carbonization route to fabricate graphene-like carbon nanosheet wrapped SiO_(x)/C submicrospheres(SiO_(x)/C@2D-C).The in-situ generated carbon nanosheets under molten salt condition can further improve the electroconductivity,restrain the volumetric expansion and guarantee the structural integrity of the electrode.As a result,the as-obtained SiO_(x)/C@2D-C delivers a discharge capacity of 559 mAh·g^(-1) at 0.5 A·g^(-1) after 200 cycles and 548 mAh·g^(-1) at 1.0 A·g^(-1) even after 1000 cycles.The full cell assembled with SiO_(x)/C@2D-C as anode and commercial LiFeP0_(4) as cathode can achieve an energy density of 200 Wh·kg^(-1) and maintain a capacity of 66.7% after 100 cycles with a working potential of 2.8 V.The approach is simple and cost effective,which is promising for mass production of SiO_(x)-based materials for high energy LIBs.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.21503134 and 21533005)the National Key Research and Development Program of China(2016YFB0101201).
文摘An environment-friendly,water-soluble,and cellulose based binder(lithium carboxymethyl cellulose,CMC-Li)was successfully synthesized by using Li+to replace Na+in the commercial sodium carboxymethyl cellulose(CMC-Na).Li-O2 batteries based on the CMC-Li binder present enhanced discharge specific capacities(11151 mAh/g at 100 mA/g)and a superior cycling stability(100 cycles at 200 mA/g)compared with those based on the CMC-Na binder.The enhanced performance may originate from the electrochemical stability of the CMC-Li binder and the ion-conductive nature of CMC-Li,which promotes the diffusion of Li+in the cathode and consequently retards the increase of charge transfer resistance of the cathode during cycling.The results show that the water-soluble CMC-Li binder can be a green substitute for poly(vinylidene fluoride)(PVDF)binder based on organic solvent in the lithium oxygen batteries(LOBs).
