Antisolvent addition has been widely studied in crystallization in the pharmaceutical industries by breaking the solvation balance of the original solution. Here we report a similar antisolvent ...strategy to boost Zn reversibility via regulation of the electrolyte on a molecular level. By adding for example methanol into ZnSO4 electrolyte, the free water and coordinated water in Zn2+ solvation sheath gradually interact with the antisolvent, which minimizes water activity and weakens Zn2+ solvation. Concomitantly, dendrite‐free Zn deposition occurs via change in the deposition orientation, as evidenced by in situ optical microscopy. Zn reversibility is significantly boosted in antisolvent electrolyte of 50 % methanol by volume (Anti‐M‐50 %) even under harsh environments of −20 °C and 60 °C. Additionally, the suppressed side reactions and dendrite‐free Zn plating/stripping in Anti‐M‐50 % electrolyte significantly enhance performance of Zn/polyaniline coin and pouch cells. We demonstrate this low‐cost strategy can be readily generalized to other solvents, indicating its practical universality. Results will be of immediate interest and benefit to a range of researchers in electrochemistry and energy storage.
Water activity and Zn2+ solvation in an ZnSO4 electrolyte are regulated by adding methanol as antisolvent. Methanol gradually interacts with the free and coordinated water in the Zn2+ solvation sheath in the electrolyte, to suppress side reactions and enhance the Zn2+ transference number. Concomitantly, Zn2+ deposition orientation is changed, resulting in dendrite‐free Zn deposition and boosted Zn reversibility.
Zinc‐based electrochemistry is attracting significant attention for practical energy storage owing to its uniqueness in terms of low cost and high safety. However, the grid‐scale application is ...plagued by limited output voltage and inadequate energy density when compared with more conventional Li‐ion batteries. Herein, we propose a latent high‐voltage MnO2 electrolysis process in a conventional Zn‐ion battery, and report a new electrolytic Zn–MnO2 system, via enabled proton and electron dynamics, that maximizes the electrolysis process. Compared with other Zn‐based electrochemical devices, this new electrolytic Zn–MnO2 battery has a record‐high output voltage of 1.95 V and an imposing gravimetric capacity of about 570 mAh g−1, together with a record energy density of approximately 409 Wh kg−1 when both anode and cathode active materials are taken into consideration. The cost was conservatively estimated at <US$ 10 per kWh. This result opens a new opportunity for the development of Zn‐based batteries, and should be of immediate benefit for low‐cost practical energy storage and grid‐scale applications.
High‐voltage and scalable energy storage was demonstrated for a new electrolytic Zn–MnO2 battery system. Because of the new mechanism of two‐electron electrolysis/electrodeposition of Zn/Zn2+ and Mn4+/Mn2+, the system displayed a record‐high output voltage (1.95 V) and energy density (ca. 409 Wh kg−1). In addition, the electrolysis process was modeled by DFT calculations.
Abstract
Electroreduction of carbon dioxide (CO
2
) into multicarbon products provides possibility of large-scale chemicals production and is therefore of significant research and commercial ...interest. However, the production efficiency for ethanol (EtOH), a significant chemical feedstock, is impractically low because of limited selectivity, especially under high current operation. Here we report a new silver–modified copper–oxide catalyst (dCu
2
O/Ag
2.3%
) that exhibits a significant Faradaic efficiency of 40.8% and energy efficiency of 22.3% for boosted EtOH production. Importantly, it achieves CO
2
–to–ethanol conversion under high current operation with partial current density of 326.4 mA cm
−2
at −0.87 V vs reversible hydrogen electrode to rank highly significantly amongst reported Cu–based catalysts. Based on in situ spectra studies we show that significantly boosted production results from tailored introduction of Ag to optimize the coordinated number and oxide state of surface Cu sites, in which the
*
CO adsorption is steered as both atop and bridge configuration to trigger asymmetric C–C coupling for stablization of EtOH intermediates.
Rhenium disulfide (ReS2) is a two‐dimensional (2D) group VII transition metal dichalcogenide (TMD). It is attributed with structural and vibrational anisotropy, layer‐independent electrical and ...optical properties, and metal‐free magnetism properties. These properties are unusual compared with more widely used group VI‐TMDs, e.g., MoS2, MoSe2, WS2 and WSe2. Consequently, it has attracted significant interest in recent years and is now being used for a variety of applications including solid state electronics, catalysis, and, energy harvesting and energy storage. It is anticipated that ReS2 has the potential to be equally used in parallel with isotropic TMDs from group VI for all known applications and beyond. Therefore, a review on ReS2 is very timely. In this first review on ReS2, we critically analyze the available synthesis procedures and their pros/cons, atomic structure and lattice symmetry, crystal structure, and growth mechanisms with an insight into the orientation and architecture of domain and grain boundaries, decoupling of structural and vibrational properties, anisotropic electrical, optical, and magnetic properties impacted by crystal imperfections, doping and adatoms adsorptions, and contemporary applications in different areas.
ReS2 is reviewed comprehensively for the first time, including the state‐of‐the‐art progress and prospects of the synthesis, fundamental properties, and applications.
Lithium‐sulfur batteries hold promise for next‐generation batteries. A problem, however, is rapid capacity fading. Moreover, atomic‐level understanding of the chemical interaction between sulfur host ...and polysulfides is poorly elucidated from a theoretical perspective. Here, a two‐dimensional (2D) heterostructured MoN‐VN is fabricated and investigated as a new model sulfur host. Theoretical calculations indicate that electronic structure of MoN can be tailored by incorporation of V. This leads to enhanced polysulfides adsorption. Additionally, in situ synchrotron X‐ray diffraction and electrochemical measurements reveal effective regulation and utilization of the polysulfides in the MoN‐VN. The MoN‐VN‐based lithium‐sulfur batteries have a capacity of 708 mA h g−1 at 2 C and a capacity decay as low as 0.068 % per cycle during 500 cycles with sulfur loading of 3.0 mg cm−2.
V for victory: A two‐dimensional MoN‐VN heterostructure is investigated as a model sulfur host. The heterostructure can regulate polysulfides and improve sulfur utilization efficiency, resulting in superior rating and cycling performance. More importantly, incorporation of V in the heterostructure can effectively tailor the electronic structure of MoN, leading to enhanced polysulfides adsorption.
Development of easy‐to‐make, highly active, and stable bifunctional electrocatalysts for water splitting is important for future renewable energy systems. Three‐dimension (3D) porous Ni/Ni8P3 and ...Ni/Ni9S8 electrodes are prepared by sequential treatment of commercial Ni‐foam with acid activation, followed by phosphorization or sulfurization. The resultant materials can act as self‐supported bifunctional electrocatalytic electrodes for direct water splitting with excellent activity toward oxygen evolution reaction and hydrogen evolution reaction in alkaline media. Stable performance can be maintained for at least 24 h, illustrating their versatile and practical nature for clean energy generation. Furthermore, an advanced water electrolyzer through exploiting Ni/Ni8P3 as both anode and cathode is fabricated, which requires a cell voltage of 1.61 V to deliver a 10 mA cm−2 water splitting current density in 1.0 m KOH solution. This performance is significantly better than that of the noble metal benchmark—integrated Ni/IrO2 and Ni/Pt–C electrodes. Therefore, these bifunctional electrodes have significant potential for realistic large‐scale production of hydrogen as a replacement clean fuel to polluting and limited fossil‐fuels.
Three‐dimension nickel‐based electrocatalytic electrodes (Ni/Ni8P3 and Ni/Ni9S8) are developed for application in water splitting. The as‐obtained Ni/Ni8P3 catalytic electrode, particularly exhibiting excellent electrocatalytic activity and stability due to its advanced structure effects, can serve as a highly efficient and stable bifunctional catalyst for overall water splitting.
Heteroatom-doping is a practical means to boost RuO
for acidic oxygen evolution reaction (OER). However, a major drawback is conventional dopants have static electron redistribution. Here, we report ...that Re dopants in Re
Ru
O
undergo a dynamic electron accepting-donating that adaptively boosts activity and stability, which is different from conventional dopants with static dopant electron redistribution. We show Re dopants during OER, (1) accept electrons at the on-site potential to activate Ru site, and (2) donate electrons back at large overpotential and prevent Ru dissolution. We confirm via in situ characterizations and first-principle computation that the dynamic electron-interaction between Re and Ru facilitates the adsorbate evolution mechanism and lowers adsorption energies for oxygen intermediates to boost activity and stability of Re
Ru
O
. We demonstrate a high mass activity of 500 A g
(7811 A g
) and a high stability number of S-number = 4.0 × 10
n
n
to outperform most electrocatalysts. We conclude that dynamic dopants can be used to boost activity and stability of active sites and therefore guide the design of adaptive electrocatalysts for clean energy conversions.
Abstract
Renewable energy-based electrocatalytic oxidation of organic nucleophiles (e.g.methanol, urea, and amine) are more thermodynamically favourable and, economically attractive to replace ...conventional pure water electrooxidation in electrolyser to produce hydrogen. However, it is challenging due to the competitive oxygen evolution reaction under a high current density (e.g., >300 mA cm
−2
), which reduces the anode electrocatalyst’s activity and stability. Herein, taking lower energy cost urea electrooxidation reaction as the model reaction, we developed oxyanion-engineered Nickel catalysts to inhibit competing oxygen evolution reaction during urea oxidation reaction, achieving an ultrahigh 323.4 mA cm
−2
current density at 1.65 V with 99.3 ± 0.4% selectivity of N-products. In situ spectra studies reveal that such in situ generated oxyanions not only inhibit OH
−
adsorption and guarantee high coverage of urea reactant on active sites to avoid oxygen evolution reaction, but also accelerate urea’s C − N bond cleavage to form CNO
−
intermediates for facilitating urea oxidation reaction. Accordingly, a comprehensive mechanism for competitive adsorption behaviour between OH
−
and urea to boost urea electrooxidation and dynamic change of Ni active sites during urea oxidation reaction was proposed. This work presents a feasible route for high-efficiency urea electrooxidation reaction and even various electrooxidation reactions in practical applications.
Although proton exchange membrane (PEM) water electrolyzers offer a promising means for generation of hydrogen fuel from solar and wind energy, in acidic environments the corresponding anodic oxygen ...evolution reaction (OER) remains a bottleneck. Because the activity and stability of electrocatalysts depend significantly on physicochemical properties, material surface and interface engineering can offer a practical way to boost performance. To date, significant advances have been made using a judicious combination of advanced theoretical computations and spectroscopic characterizations. To provide a critical assessment of this field, we focus on the establishment of material property–catalytic activity relationships. We start with a detailed exploration of prevailing OER mechanisms in acid solution through evaluating the role of catalyst lattice oxygen. We then critically review advances in surface and interface engineering in acidic OER electrocatalysts from both experimental and theoretical perspectives. Finally, a few promising research orientations are proposed to inspire future investigation of high-performance PEM catalysts.
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