Practical application of aqueous Zn‐ion batteries (AZIBs) is significantly limited by poor reversibility of the Zn anode. This is because of 1) dendrite growth, and 2) water‐induced parasitic ...reactions including hydrogen evolution, during cycling. Here for the first time an elegantly simple method is reported that introduces ethylene diamine tetraacetic acid tetrasodium salt (Na4EDTA) to a ZnSO4 electrolyte. This is shown to concomitantly suppress dendritic Zn deposition and H2 evolution. Findings confirm that EDTA anions are adsorbed on the Zn surface and dominate active sites for H2 generation and inhibit water electrolysis. Additionally, adsorbed EDTA promotes desolvation of Zn(H2O)62+ by removing H2O molecules from the solvation sheath of Zn2+. Side reactions and dendrite growth are therefore suppressed by using the additive. A high Zn reversibility with Coulombic efficiency (CE) of 99.5% and long lifespan of 2500 cycles at 5 mAh cm−2, 2 mAh cm−2 is demonstrated. Additionally, the highly reversible Zn electrode significantly boosts overall performance of VO2//Zn full‐cells. These findings are expected to be of immediate benefit to a range of researchers in using dual‐function additives to suppress Zn dendrite and parasitic reactions for electrochemistry and energy storage applications.
A dual‐function additive, ethylene diamine tetraacetic acid tetrasodium salt (Na4EDTA), is applied in a ZnSO4 electrolyte to boost the reversibility of Zn anodes via electrolysis inhibition and desolvation promotion. These characteristics originate from the high adsorption ability of EDTA on the Zn surface, and strong interaction with Zn2+ hydrated ions. The EDTA‐containing electrolyte endows high Coulombic efficiency, stable voltage profiles and stable cycling performance to VO2//Zn cells.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Aqueous Zn–iodine (Zn–I2) batteries have been regarded as a promising energy‐storage system owing to their high energy/power density, safety, and cost‐effectiveness. However, the polyiodide shuttling ...results in serious active mass loss and Zn corrosion, which limits the cycling life of Zn–I2 batteries. Inspired by the chromogenic reaction between starch and iodine, a structure confinement strategy is proposed to suppress polyiodide shuttling in Zn–I2 batteries by hiring starch, due to its unique double‐helix structure. In situ Raman spectroscopy demonstrates an I5−‐dominated I−/I2 conversion mechanism when using starch. The I5− presents a much stronger bonding with starch than I3−, inhibiting the polyiodide shuttling in Zn–I2 batteries, which is confirmed by in situ ultraviolet–visible spectra. Consequently, a highly reversible Zn–I2 battery with high Coulombic efficiency (≈100% at 0.2 A g−1) and ultralong cycling stability (>50 000 cycles) is realized. Simultaneously, the Zn corrosion triggered by polyiodide is effectively inhibited owing to the desirable shuttling‐suppression by the starch, as evidenced by X‐ray photoelectron spectroscopy analysis. This work provides a new understanding of the failure mechanism of Zn–I2 batteries and proposes a cheap but effective strategy to realize high‐cyclability Zn–I2 batteries.
Inspired by the significant chromogenic reaction between starch and iodine, the shuttle effect of Zn–I2 batteries is effectively addressed by using starch, which strongly anchors polyiodide anions due to its unique double‐helix structure. Benefiting from this structure confinement, a Coulombic efficiency of almost 100% and an ultralong life of 50 000 cycles are realized in Zn–I2 batteries.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Defects have been found to enhance the electrocatalytic performance of NiFe‐LDH for oxygen evolution reaction (OER). Nevertheless, their specific configuration and the role played in regulating the ...surface reconstruction of electrocatalysts remain ambiguous. Herein, cationic vacancy defects are generated via aprotic‐solvent‐solvation‐induced leaking of metal cations from NiFe‐LDH nanosheets. DFT calculation and in situ Raman spectroscopic observation both reveal that the as‐generated cationic vacancy defects tend to exist as VM (M=Ni/Fe); under increasing applied voltage, they tend to assume the configuration VMOH, and eventually transform into VMOH‐H which is the most active yet most difficult to form thermodynamically. Meanwhile, with increasing voltage the surface crystalline Ni(OH)x in the NiFe‐LDH is gradually converted into disordered status; under sufficiently high voltage when oxygen bubbles start to evolve, local NiOOH species become appearing, which is the residual product from the formation of vacancy VMOH‐H. Thus, we demonstrate that the cationic defects evolve along with increasing applied voltage (VM → VMOH → VMOH‐H), and reveal the essential motif for the surface restructuration process of NiFe‐LDH (crystalline Ni(OH)x → disordered Ni(OH)x → NiOOH). Our work provides insight into defect‐induced surface restructuration behaviors of NiFe‐LDH as a typical precatalyst for efficient OER electrocatalysis.
Along with increasing voltage during the OER process, the structural evolution of cationic defects within NiFe‐LDH, where the simple vacancy VM changes to VMOH and then to the most reactive VMOH‐H, and the surface restructuration, where surface crystalline Ni(OH)x is converted to disordered Ni(OH)x and then to the surface local NiOOH species, are voltage‐regulated concurrent events defining the eventual catalytic performance of the precatalyst.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Sulfide‐based all‐solid‐state lithium‐ion batteries (ASSLIBs) are the widely recognized approach toward high safety owing to excellent ionic conductivity and nonflammable nature of solid‐state ...electrolytes (SSEs). However, narrow potential window of SSEs brings about serious interfacial parasitic reactions, resulting in fast degradation of the battery. Herein, a glassy/ceramic analogous solid electrolyte interface (SEI) is constructed on LiCoO2 (LCO) to enhance interfacial stability between LCO and the Li10GeP2S12 (LGPS) SSEs. In which, ceramic Li2TiO3 guarantees good mechanical toughness of analogous SEI, while glassy LixByOz reinforces the coverage to avoid parasitic reactions. Analogous SEI endows ASSLIBs with excellent cycling and rate performance under an upper charge voltage of 4.3 V with 82.3% capacity retention after 300 cycles at 0.2 C. When pushing charge voltage to 4.5 V, analogous SEI also enables desirable performance with an initial capacity of 172.7 mAh g−1 and long lifespan of 200 cycles at 0.2 C. Both experiments and theoretical computation reveal excellent stability between analogous SEI and LGPS, which endows ASSLIBs with small polarization and improved performance. This work provides an insight on glassy/ceramic analogous SEI strategy to boost the interfacial stability of ASSLIBs.
Inspiring by solid electrolyte interphase (SEI) in conventional Li‐ion batteries, an analogous SEI issuccessfully encapsulated on the LiCoO2 to overcome the instable interface between LiCoO2 and Li10GeP2S12 in all‐solid‐state lithium‐ion batteries (ASSLIBs). This analogous SEI with ceramic Li2TiO3 and glassy LixByOz enables a robust coating layer, endowing ASSLIBs with excellent durability under high charge voltage of 4.5 V.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Metallic lithium/sodium (Li/Na) is considered an attractive anode for future high‐energy‐density batteries. The root causes of preventing their applications come from uneven Li/Na nucleation and ...subsequent dendrite formation. Here, a cost‐efficient and scalable solid‐to‐solid transfer method for dense buffer layer construction on Li/Na anodes is proposed, and thin lithiophilic/sodiophilic buffer layers based on natural silk fibers derived carbon (SFC) and carbon nanotubes (CNTs) composites (denoted as SFC/CNTs) are adopted, which facilitate uniform Li/Na nucleation and dendrite‐free, lateral growth behavior upon recurring Li/Na plating/stripping processes. Lithiopilic/sodiophilic buffer layers enable long‐term cycling stability (>250 cycles) with high Coulombic efficiency (99.2% for Li and 98.8% for Na), low polarization, and flat voltage profiles. More importantly, the cycling performance of LiFePO4|Li pouch cells is largely enhanced with a lifespan of 390 cycles. Further, using ultra‐thin Li anodes (25 μm) also achieves stable LiNi1/3Mn1/3Co1/3O2|Li cells with 200 cycles under a low negative/positive ratio (1.67). Similar achievement is also realized in Na‐metal batteries with negligible capacity fading for over 600 cycles in Na3V2(PO4)3|Na cells, further demonstrating that SFC/CNT buffer layer is technically viable in practical batteries. This study provides a facile strategy for fabricating dense and uniform lithiophilic/sodiophilic buffer layers for low‐cost and scale‐up energy storage devices.
Natural silk fiber derived N/S‐functionalized porous carbon flakes are elucidated to regular the lithium/sodium (Li/Na) growth patterns from vertical to lateral direction, and a novel solid‐to‐solid transfer method is applied for dense and uniform buffer layer fabrication. The modified Li/Na anodes reveal a high performance in Li‐based pouch cells (390 cycles), and negligible fading in Na‐based coin cells (600 cycles).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
To conquer the bottleneck of sluggish kinetics in cathodic oxygen reduction reaction (ORR) of metal‐air batteries, catalysts with dual‐active centers have stood out. Here, a “pre‐division metal ...clusters” strategy is firstly conceived to fabricate a N,S‐dual doped honeycomb‐like carbon matrix inlaid with CoN4 sites and wrapped Co2P nanoclusters as dual‐active centers (Co2P/CoN4@NSC‐500). A crystalline {CoII2} coordination cluster divided by periphery second organic layers is well‐designed to realize delocalized dispersion before calcination. The optimal Co2P/CoN4@NSC‐500 executes excellent 4e− ORR activity surpassing the benchmark Pt/C. Theoretical calculation results reveal that the CoN4 sites and Co2P nanoclusters can synergistically quicken the formation of *OOH on Co sites. The rechargeable Zn‐air battery (ZAB) assembled by Co2P/CoN4@NSC‐500 delivers ultralong cycling stability over 1742 hours (3484 cycles) under 5 mA cm−2 and can light up a 2.4 V LED bulb for ≈264 hours, evidencing the promising practical application potentials in portable devices.
A “pre‐division metal clusters” strategy is first conceived to fabricate dual‐active center catalysts (Co2P/CoN4@NSC‐500) with dispersed CoN4 and Co2P sites. The optimal catalyst executes superior ORR activity and was applied in ultralong Zn‐air batteries surpassing the benchmark 20 % Pt/C. Theoretical calculations demonstrate that the dual‐active sites synergistically quicken the formation of the *OOH intermediate, greatly boosting the performance.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The lithium–oxygen (Li–O2) battery with high energy density of 3860 Wh kg−1 represents one of the most promising new secondary batteries for future electric vehicles and mobile electronic devices. ...However, slow oxygen reduction/oxygen evolution (ORR/OER) reaction efficiency and unstable cycling performance restrain the practical applications of the Li–O2 battery. Herein, Ru‐modified nitrogen‐doped porous carbon‐encapsulated Co nanoparticles (Ru/Co@CoNx–C) are synthesized through reduction of Ru on metal–organic framework (MOFs) pyrolyzed derivatives strategies. Porous carbon polyhedra provide channels for reactive species and stable structure ensures the cyclic stability of the catalyst; abundant Co–Nx sites and high specific surface area (353 m2 g−1) provide more catalytically active sites and deposition sites for reaction products. Theoretical calculations further verify that Ru/Co@CoNx–C can regulate the growth of Li2O2 to improve reversibility of Li–O2 batteries. Li–O2 batteries with Ru/Co@CoNx–C as cathode catalyst achieve small voltage gaps of 1.08 V, exhibit excellent cycle stability (205 cycles), and deliver high discharge specific capacity (17050 mAh g−1). Furthermore, pouch‐type Li–O2 batteries that maintain stable electrochemical performance output even under conditions of bending deformation and corner cutting are successfully assembled. This study demonstrates Ru/Co@CoNx–C catalyst's great application potential in Li–O2 batteries.
A composite catalyst of highly dispersed Ru–Co nanoparticles and nitrogen‐doped carbon polyhedron is prepared as Li–O2 cathode. The stable porous carbon structure, uniformly dispersed, and abundant Co–Nx active sites, and the presence of the ultrafine Ru nanoparticles enables efficient and reversible formation and decomposition of Li2O2 with low overpotential and high discharge specific capacity.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Li2CO3 is the cathodic discharge product of a Li-CO2/O2 battery and is difficult to electrochemically decompose. The accumulation of Li2CO3 leads to battery degradation and results in a short ...lifespan. Herein, a carbon nanotube supported Ru/NiO@Ni catalyst (Ru/NiO@Ni/CNT) is synthesized with Ru nanoparticles (∼2.5 nm) anchored on the surface of core–shell structure NiO@Ni nanoparticles (∼17 nm). We found strong interfacial interactions between Ru nanoparticles and NiO. XRD and XPS analysis revealed that the presence of Ru could protect the Ni species from being deeply oxidized while the NiO species could modify the local electronic structure of Ru, inducing a higher oxidation state. When such a Ru/NiO@Ni/CNT catalyst is used as a cathode in Li-CO2/O2 (v:v = 4:1) batteries, a long cycling life of 105 cycles at a cutoff capacity of 1000 mAh g–1 with an overpotential as low as 1.01 V was achieved, which is significantly better than 75 and 44 cycles with Ru/CNT and NiO@Ni/CNT catalysts, respectively, and confirms the strong synergetic effect between the Ru and NiO species in the electrocatalytic decomposition of Li2CO3. Density functional theory (DFT) calculations of the electrochemical decomposition of Li2CO3 with the assistance of RuO2 indicates that the formation of O2 is the rate-determining step. In addition, the formation and decomposition process of Li2CO3 was illuminated at a molecular level by in situ FTIR spectroscopy with Ru/NiO@Ni/CNT catalysts.
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IJS, KILJ, NUK, PNG, UL, UM
Zn–iodine (I2) battery, as a promising energy storage device, especially under high I2 loading, is harassed by the shuttle effect of the soluble polyiodide intermediates. Herein, the bifunctional ...role of 2D carbon nanosponge with rich P‐dopant (4.2 at%) and large specific surface area (1966 m2 g−1) in anchoring I2/Ix− (x = 1, 3 or 5) and catalyzing their mutual conversion is reported. Both experiment and computational results reveal the transfer of electrons from the P‐doped site to iodine species, showing strong interfacial interaction. When being used as a host, it possesses high specific capture capacity for I2 (3.34 giodine g−1 or 1.6 mgiodine m−2) and Ix− (6.12 gtriiodide g−1 or 3.1 mgtriiodide m−2), which thus effectively suppresses the shuttle effect, supported by in situ UV–vis and Raman spectra. In addition to the strong interfacial interaction that favors iodine conversion, the P‐doped sites can also catalyze the conversion of I5− to I2, which is the rate‐determining step. Consequently, Zn–I2 batteries under a high I2 content (70 wt%) deliver high specific capacity (220.3 mAh g−1), superior Coulombic efficiency (>99%), and low self‐discharge rate; moreover, they can also operate steadily at 2 A g−1 with ignorable capacity decay for 10 000 cycles.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Electrochemical water splitting is convinced as one of the most promising solutions to combat the energy crisis. The exploitation of efficient hydrogen and oxygen evolution reaction (HER/OER) ...bifunctional electrocatalysts is undoubtedly a vital spark yet challenging for imperative green sustainable energy. Herein, through introducing a simple pH regulated redox reaction into a tractable hydrothermal procedure, a hierarchical Fe
3
O
4
@MnO
x
binary metal oxide core-shell nano-polyhedron was designed by evolving MnO
x
wrapped Fe
3
O
4
. The MnO
x
effectively prevents the agglomeration and surface oxidation of Fe
3
O
4
nano-particles and increases the electrochemically active sites. Benefiting from the generous active sites and synergistic effects of Fe
3
O
4
and MnO
x
, the Fe
3
O
4
@MnO
x
-NF nanocomposite implements efficient HER/OER bifunctional electrocatalytic performance and overall water splitting. As a result, hierarchical Fe
3
O
4
@MnO
x
only requires a low HER/OER overpotential of 242/188 mV to deliver 10 mA cm
−2
, a small Tafel slope of 116.4/77.6 mV dec
−1
, combining a long-term cyclability of 5 h. Impressively, by applying Fe
3
O
4
@MnO
x
as an independent cathode and anode, the overall water splitting cell supplies a competitive voltage of 1.64 V to achieve 10 mA cm
−2
and super long cyclability of 80 h. These results reveal that this material is a promising candidate for practical water electrolysis application.
A hierarchical Fe
3
O
4
@MnO
x
binary metal oxide core-shell nano-polyhedron executes excellent HER/OER bifunctional electrocatalytic activities due to abundant active sites and the synergistic effects of each component.
