查看更多>>摘要：Chloride solid electrolytes possess multiple advantages for the construction of safe,energy-dense all-solid-state sodium batteries,but presently the chlorides with sufficiently high cost-competitiveness for commercialization almost all exhibit low Na-ion conductivities of around 10-5 S cm-1 or lower.Here,we report a chloride solid electrolyte,Na2.7ZrCl5.3O0.7,which reaches a Na-ion conductivity of 2.29 × 10-4 S cm-1 at 25 ℃ without involving overly expensive raw materials such as rare-earth chlo-rides or Na2S.In addition to the efficient ion transport,Na2.7ZrCl5.3O0.7 also shows an excellent deforma-bility surpassing that of the widely studied Na3PS4,Na3SbS4,and Na2ZrCl6 solid electrolytes.The combination of these advantages allows the all-solid-state cell based on Na2.7ZrCl5.3O0.7 and NaCrO2 to realize stable room-temperature cycling at a much higher specific current than those based on other non-viscoelastic chloride solid electrolytes in literature(120 mA g-1 vs.12-55 mA g-1);after 100 cycles at such a high rate,the Na2.7ZrCl5.3O0.7-based cell can still deliver a discharge capacity of 80 mAh g-1 at 25 ℃.
查看更多>>摘要：Exploring suitable high-capacity V2O5-based cathode materials is essential for the rapid advancement of aqueous zinc ion batteries(ZIBs).However,the typical problem of slow Zn2+diffusion kinetics has severely limited the feasibility of such materials.In this work,unique hydrated vanadates(CaVO,BaVO)were obtained by intercalation of Ca2+or Ba2+into hydrated vanadium pentoxide.In the CaVO//Zn and BaVO//Zn batteries systems,the former delivered up to a 489.8 mAh g-1 discharge specific capac-ity at 0.1 A g-1.Moreover,the remarkable energy density of 370.07 Wh kg-1 and favorable cycling sta-bility yard outperform BaVO,pure V2O5,and many reported cathodes of similar ionic intercalation compounds.In addition,pseudocapacitance analysis,galvanostatic intermittent titration(GITT)tests,and Trasatti analysis revealed the high capacitance contribution and Zn2+diffusion coefficient of CaVO,while an in-depth investigation based on EIS elucidated the reasons for the better electrochemical perfor-mance of CaVO.Notably,ex-situ XRD,XPS,and TEM tests further demonstrated the Zn2+insertion/extrac-tion and Zn-storage mechanism that occurred during the cycle in the CaVO//Zn battery system.This work provides new insights into the intercalation of similar divalent cations in vanadium oxides and offers new solutions for designing cathodes for high-capacity aqueous ZIBs.
查看更多>>摘要：Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocat-alytic activity of carbon materials.However,the controllable construction of high-density and specific topological defects in carbon frameworks to reveal the relationship between reactivity and defect struc-ture remains a challenging task.Herein,the intrinsic pentagon carbon sites that can favor electron over-flow and enhance their binding affinity towards the intermediates of catalytic reaction are firstly presented by the work function and the p-band center calculations.To experimentally verify this,the cage-opening reaction of fullerene is proposed and utilized for synthesizing carbon quantum dots with specific pentagon configuration(CQDs-P),subsequently utilizing CQDs-P to modulate the micro-scale defect density of three-dimensional reduced graphene oxide(rGO)via π-π interactions.The multiple spatial-scale rGO-conjugated CQDs-P structure simultaneously possesses abundant pentagon and edge defects as catalytic active sites and long-range-ordered π electron delocalization system as conductive network.The defects-rich CQDs-P/rGO-4 all-carbon-based catalyst exhibits superb catalytic activity for triiodide reduction reaction with a high photoelectric conversion efficiency of 8.40％,superior to the Pt reference(7.97％).Theoretical calculations suggest that pentagon defects in the carbon frameworks can promote charge transfer and modulate the adsorption/dissociation behavior of the reaction intermedi-ates,thus enhancing the electrocatalytic activity of the catalyst.This work confirms the role of intrinsic pentagon defects in catalytic reactions and provides a new insight into the synthesis of defects-rich car-bon catalysts.
查看更多>>摘要：The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasma-assisted aerogel(PAG)interface engineering was proposed as efficient ion transport modulator that can simultaneously regulate uniform Zn2+flux and desolvation behavior during battery operation.The PAG with ordered mesopores acted as an ion sieve to homogenize Zn deposition and accelerate Zn2+flux,which is favorable for corrosion resistance and dendrite suppression.Importantly,the plasma-assisted aerogel with abundant hydrophilic groups can facilitate the desolvation kinetics of Zn2+due to the mul-tiple hydrogen-bonding interaction with the activated water molecules,thus accelerating the Zn2+migra-tion kinetics.Consequently,the Zn/Zn cell assembled with PAG-modified separator demonstrates stable plating and stripping behavior(over 1400 h at 1 mA cm-2)and high Coulombic efficiency(99.8％at 1 mA cm-2 after 1100 cycles),and the Zn||MnO2 full cell shows excellent long-term cycling stability and maintains a high capacity of 154.9 mA h g-1 after 1000 cycles at 1 A g-1.This study provides a fea-sible approach for the large-scale fabrication of aerogel functionalized separators to realize ultra-stable Zn metal batteries.
查看更多>>摘要：With the rapid development of portable electronics,new energy vehicles,and smart grids,ion batteries are becoming one of the most widely used energy storage devices,while the safety concern of ion batter-ies has always been an urgent problem to be solved.To develop a safety-guaranteed battery,the charac-terization of the internal structure is indispensable,where electron microscopy plays a crucial role.Based on this,this paper summarizes the application of transmission electron microscopy(TEM)in battery safety,further concludes and analyzes the aspects of dendrite growth and solid electrolyte interface(SEI)formation that affect the safety of ion batteries,and emphasizes the importance of electron micro-scopy in battery safety research and the potential of these techniques to promote the future development of this field.These advanced electron microscopy techniques and their prospects are also discussed.
查看更多>>摘要：The development of aqueous Zn batteries is limited by parasitic water reactions,corrosion,and dendrite growth.To address these challenges,an inner Helmholtz plane(IHP)regulation method is proposed by employing low-cost,non-toxic maltitol as the electrolyte additive.The preferential adsorption behavior of maltitol can expel the water from the inner Helmholtz plane,and thus hinder the immediate contact between Zn metal and H2O.Meanwhile,strong interaction between maltitol and H2O molecules can restrain the activity of H2O.Besides,the"IHP adsorption effect"along with the low LUMO energy level of maltitol-CF3SO3 can promote the in-situ formation of an organic-inorganic complex solid electrolyte interface(SEI)layer.As a result,the hydrogen/oxygen evolution side reaction,corrosion,and dendrites issues are effectively suppressed,thereby leading to highly reversible and dendrite-free Zn plating/strip-ping.The Zn||I2 battery with hybrid electrolytes also demonstrates high electrochemical performance and ultralong cycling stability,showing a capacity retention of 75％over 20000 charge-discharge cycles at a large current density of 5 A g-1.In addition,the capacity of the device has almost no obvious decay over 20000 cycles even at-30 ℃.This work offers a successful electrolyte regulation strategy via the IHP adsorption effect to design electrolytes for high-performance rechargeable Zn-ion batteries.
查看更多>>摘要：Single-crystal Ni-rich cathodes are a promising candidate for high-energy lithium-ion batteries due to their higher structural and cycling stability than polycrystalline materials.However,the phase evolution and capacity degradation of these single-crystal cathodes during continuous lithation/delithation cycling remains unclear.Understanding the mapping relationship between the macroscopic electrochemical properties and the material physicochemical properties is crucial.Here,we investigate the correlation between the physical-chemical characteristics,phase transition,and capacity decay using capacity differ-ential curve feature identification and in-situ X-ray spectroscopic imaging.We systematically clarify the dominant mechanism of phase evolution in aging cycling.Appropriately high cut-off voltages can miti-gate the slow kinetic and electrochemical properties of single-crystal cathodes.We also find that second-order differential capacity discharge characteristic curves can be used to identify the crystal structure disorder of Ni-rich cathodes.These findings constitute a step forward in elucidating the corre-lation between the electrochemical extrinsic properties and the physicochemical intrinsic properties and provide new perspectives for failure analysis of layered electrode materials.
查看更多>>摘要：Kesterite Cu2ZnSn(S,Se)4(CZTSSe)solar cells suffer from severe carrier recombination,limiting the pho-tovoltaic performance.Unfavorable energy band alignment at the p-n junction and defective front inter-face are two main causes.Herein,oxygen incorporation in CZTSSe via absorber air-annealing was developed as a strategy to optimize its surface photoelectric property and reduce the defects.With opti-mized oxygen incorporation conditions,the carrier separation and collection behavior at the front inter-face of the device is improved.In particular,it is found that oxygen incorporated absorber exhibits increased band bending,larger depletion region width,and suppressed absorber defects.These indicate the dynamic factors for carrier separation become stronger.Meanwhile,the increased potential differ-ence between grain boundaries and intra grains combined with the decreased concentration of interface deep level defect in the absorber provide a better path for carrier transport.As a consequence,the cham-pion efficiency of CZTSSe solar cells has been improved from 9.74％to 12.04％with significantly improved open-circuit voltage after optimized air-annealing condition.This work provides a new insight for inter-face engineering to improve the photoelectric conversion efficiency of CZTSSe devices.
查看更多>>摘要：Aqueous electrochromic battery(ECB)has shown intense potential for achieving energy storage and sav-ing simultaneously.While tungsten oxide(WO3)is the most promising EC material for commercializa-tion,the cycling stability of WO3-based aqueous ECBs is currently unsatisfactory due to the repeated phase transition during the redox process and the corrosion by acidic electrolytes.Herein,we present a titanium-tungsten oxide alloy(Ti-WO3)with controllable morphology and crystal phase synthesized by a facile hot injection method to overcome the challenges.In contrast to conventional monoclinic WO3,the Ti-WO3 nanorods can stably maintain their cubic crystal phase during the redox reaction in an acidic electrolyte,thus leading to dramatically enhanced response speed and cycling stability.Specifically,when working in a well-matched hybrid AI3+/Zn2+aqueous electrolyte,our phase-transition-free cubic Ti-WO3 exhibits an ultra-high cycling stability(＞20000 cycles),fast response speed(3.95 s/4.65 s for bleaching/coloring),as well as excellent discharge areal capacity of 214.5 mA h m-2.We further fabricate a fully complementary aqueous electrochromic device,for the first time,using a Ti-WO3/Prussian blue device architecture.Remarkably,the complementary ECB shows＞10000 stable operation cycles,attesting to the feasibility of our Ti-WO3 for practical applications.Our work validates the signif-icance of inhibiting the phase transitions of WO3 during the electrochromic process for realizing highly cyclable aqueous ECB,which can possibly provide a generalized design guidance for other high-quality metallic oxides for electrochemical applications.
查看更多>>摘要：Indium oxide(In2O3),as a promising candidate for CO2 hydrogenation to C1 products,often suffers from sintering and activity decline,closely related to the undesirable structural evolution under reaction con-ditions.Based on the comprehension of the dynamic evolution,this study presents an efficient strategy to alleviate the agglomeration of In2O3 nanoparticles by the surface decoration with highly dispersed silica species(SiOx).Various structural characterizations combined with density functional theory calculations demonstrated that the sintering resulted from the over-reduction,while the enhanced stability origi-nated from the anchoring effect of highly stable In-OSi bonds,which hinders the substantial formation of metallic In(In0)and the subsequent agglomeration.0.6Si/In2O3 exhibited CO2 conversion rate of 10.0 mmol g-1 h-1 at steady state vs.3.5 mmol g-1 h-1 on In2O3 in CO2 hydrogenation.Enhanced steady-state activity was also achieved on Pd-modified catalysts.Compared to the traditional Pd/In2O3 catalyst,the methanol production rate of Pd catalyst supported on 0.6Si/In2O3 was enhanced by 23％,showing the potential of In2O3 modified by SiOx in serving as a platform material.This work provides a promising method to design new In2O3-based catalysts with improved activity and stability in CO2 hydrogenation.
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