An electrolyte cation additive strategy provides a versatile route for developing high‐energy and long‐life aqueous zinc‐ion hybrid capacitors. However, the mechanisms of energy storage and Zn anode ...protection are still unclear in Zn‐based systems with dual‐ion electrolytes. Here, a dual charge storage mechanism for zinc‐ion hybrid capacitors with both cations and anions adsorption/desorption and the reversible formation of Zn4SO4(OH)6·xH2O enabled by the Mg2+ additive in the common aqueous ZnSO4 electrolyte are proposed. Theoretical calculations verify that the self‐healing electrostatic shield effect and the solvation‐sheath structure regulation rendered by the Mg2+ additive account for the observed uniform Zn deposition and dendrite suppression. As a result, an additional energy storage capacity of ≈50% compared to that in a pure 2 m ZnSO4 electrolyte and an extended cycle life with capacity retention of 98.7% after 10 000 cycles are achieved. This work highlights the effectiveness of electrolyte design for dual‐ion carrier storage mechanism in aqueous devices toward high energy density and long cycle life.
A high‐capacity Zn‐based hybrid capacitor is reported using 0.1 m MgSO4 (Mg cation additive) as an active multivalent metal‐ion charge carrier in 2 m ZnSO4 electrolyte. The Mg2+ additive contributes additional capacity, inhibits side reactions, and suppresses Zn dendrites by facilitating uniform Zn nucleation and deposition.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Materials that can produce large controllable strains are widely used in shape memory devices, actuators and sensors
, and great efforts have been made to improve the strain output
. Among them, ...ferroelastic transitions underpin giant reversible strains in electrically driven ferroelectrics or piezoelectrics and thermally or magnetically driven shape memory alloys
. However, large-strain ferroelastic switching in conventional ferroelectrics is very challenging, while magnetic and thermal controls are not desirable for practical applications. Here we demonstrate a large shear strain of up to 21.5% in a hybrid ferroelectric, C
H
N(CH
)
CdCl
, which is two orders of magnitude greater than that in conventional ferroelectric polymers and oxides. It is achieved by inorganic bond switching and facilitated by structural confinement of the large organic moieties, which prevents undesired 180° polarization switching. Furthermore, Br substitution can soften the bonds, allowing a sizable shear piezoelectric coefficient (d
≈ 4,830 pm V
) at the Br-rich end of the solid solution, C
H
N(CH
)
CdBr
Cl
. The electromechanical properties of these compounds suggest their potential in lightweight and high-energy-density devices, and the strategy described here could inspire the development of next-generation piezoelectrics and electroactive materials based on hybrid ferroelectrics.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Fiber‐based power sources are receiving interest in terms of application in wearable electronic devices. Herein, fiber‐shaped all‐solid‐state asymmetric energy storage devices are fabricated based on ...a partially nitridized NiCo2O4 hybrid nanostructures on graphite fibers (GFs). The surface nitridation leads to a 3D “pearled‐veil” network structure, in which Ni–Co–N nanospheres are mounted on NiCo2O4 nanosheets' electrode. It is demonstrated that the hybrid materials are more potent than the pure NiCo2O4 in energy storage applications due to a cooperative effect between the constituents. The Ni–Co–N segments augment the pristine oxide nanosheets by enhancing both capacity and rate performance (a specific capacity of 384.75 mAh g−1 at 4 A g−1, and a capacity retention of 86.5% as the current is increased to 20 A g−1). The whole material system has a metallic conductivity that renders high‐rate charge and discharge, and an extremely soft feature, so that it can wrap around arbitrary‐shaped holders. All‐solid‐state asymmetric device is fabricated using Ni–Co–N/NiCo2O4/GFs and carbon nanotubes/GFs as the electrodes. The flexible device delivers outstanding performance compared to most oxide‐based full devices. These structured hybrid materials may find applications in miniaturized foldable energy devices.
A “pearled‐veil” hybrid structure containing Ni–Co–N nanospheres anchored within the network of NiCo2O4 nanosheets on graphite fibers is fabricated, which shows enhanced electrochemical energy storage performance compared to the pure ternary oxide nanosheets' electrode. A full solid‐state, fiber‐shaped device is demonstrated.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The intrinsic activity of in-plane chalcogen atoms plays a significant role in the catalytic performance of transition metal dichalcogenides (TMDs). A rational modulation of the local configurations ...is essential to activating the in-plane chalcogen atoms but restricted by the high energy barrier to break the in-plane TM-X (X = chalcogen) bonds. Here, we theoretically design and experimentally realize the tuning of local configurations. The electron transfer capacity of local configurations is used to screen suitable TMDs materials for hydrogen evolution reaction (HER). Among various configurations, the triangular-shape cobalt atom cluster with a central sulfur vacancy (3Co
-V
) renders the distinct electrocatalytic performance of MoS
with much reduced overpotential and Tafel slope. The present study sheds light on deeper understanding of atomic-scale local configuration in TMDs and a methodology to boost the intrinsic activity of chalcogen atoms.
A dynamic surface reconstruction of oxide electrocatalysts in alkaline media is widely observed especially for layered double hydroxide (LDH), but little is known about how to promote the ...reconstruction toward desired surfaces for improved oxygen evolution reaction (OER). Here, surface reconstruction of NiFe LDH nanosheets is successfully induced to a higher degree via in situ sulfur doping than that by natural electrochemical activation. Theoretical calculations, operando Raman, and various ex situ characterizations reveal the S anion‐induced effect can lower the energy barrier and facilitate the phase transformation into highly active S‐doped oxyhydroxides. The generated S‐NixFeyOOH can optimize the intermediate adsorption and facilitate the OER kinetics. The reconstructed S‐oxyhydroxides catalyst presents superior OER activity and long‐term durability compared to undoped ones. This work provides a structure–composition–activity relationship during the in situ surface restructuring of NiFe LDH pre‐catalysts.
It is found that lattice doping by sulfur can promote the surface reconstruction of NiFe layered double hydroxide for enhanced oxygen evolution reaction activity. The enhancement mechanism and adsorption sites are identified.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Strain in layered transition‐metal dichalcogenides (TMDs) is a type of effective approach to enhance the catalytic performance by activating their inert basal plane. However, compared with ...traditional uniaxial strain, the influence of biaxial strain and the TMD layer number on the local electronic configuration remains unexplored. Herein, via a new in situ self‐vulcanization strategy, biaxially strained MoS2 nanoshells in the form of a single‐crystalline Ni3S2@MoS2 core–shell heterostructure are realized, where the MoS2 layer is precisely controlled between the 1 and 5 layers. In particular, an electrode with the bilayer MoS2 nanoshells shows a remarkable hydrogen evolution reaction activity with a small overpotential of 78.1 mV at 10 mA cm‐2, and negligible activity degradation after durability testing. Density functional theory calculations reveal the contribution of the optimized biaxial strain together with the induced sulfur vacancies and identify the origin of superior catalytic sites in these biaxially strained MoS2 nanoshells. This work highlights the importance of the atomic‐scale layer number and multiaxial strain in unlocking the potential of 2D TMD electrocatalysts.
The effect of biaxial strain and layer numbers of MoS2 nanoshells on the electrocatalytic activity is investigated in detail. Calculations reveal the superiority of biaxial strain over uniaxial strain and identify the ideal Mo coordination and S vacancies for maximal catalytic activity.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Despite the substantial progress in cathode materials in the past few years, rechargeable zinc batteries (RZBs) are plagued by rapid performance degradation due to dendrite formation and notorious ...side reactions at the Zn anode side. Here, an optimized hydrated eutectic electrolyte (HEE) system containing methylsulfonylmethane, zinc perchlorate, and water, in which an organic ligand coordinated the solvation shell of Zn ions with water molecules constituting the eutectic network, is proposed. Compared to common aqueous solutions, this HEE system is proven effective in promoting the smooth Zn deposition and plating/stripping reversibility as well as suppressing side reactions. The vanadium‐based zinc batteries based on this new HEE exhibit exceptionally high‐capacity retention (≈100% retention even after 1600 cycles at a relatively small current density of 1000 mA g−1). This study offers a new type of electrolyte for RZBs and a deep understanding of the effect of Zn2+ solvent sheath structure on the cycle reversibility.
A new hydrated eutectic electrolyte system containing zinc perchlorate, methylsulfonylmethane, and water is developed. The organic ligand coordinated Zn2+ solvation structure and the low activity of water promote efficient and reversible Zn platting/stripping and suppress side reactions. The vanadium‐based zinc batteries show very stable cycles.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In the literature, Zn–Mn aqueous batteries (ZMABs) confront abnormal capacity behavior, such as capacity fluctuation and diverse “unprecedented performances.” Because of the electrolyte ...additive‐induced complexes, various charge/discharge behaviors associated with different mechanisms are being reported. However, the current performance assessment remains unregulated, and only the electrode or the electrolyte is considered. The lack of a comprehensive and impartial performance evaluation protocol for ZMABs hinders forward research and commercialization. Here, a pH clue (proton‐coupled reaction) to understand different mechanisms is proposed and the capacity contribution is normalized. Then, a series of performance metrics, including rated capacity (Cr) and electrolyte contribution ratio from Mn2+ (CfM), are systematically discussed based on diverse energy storage mechanisms. The relationship between Mn (II) ↔ Mn (III) ↔ Mn (IV) conversion chemistry and protons consumption/production is well‐established. Finally, the concrete design concepts of a tunable H+/Zn2+/Mn2+ storage system for customized application scenarios, opening the door for the next‐generation high‐safety and reliable energy storage system, are proposed.
The complex energy storage mechanism of Zn–Mn aqueous batteries (ZMABs), accompanied by abnormal capacity fluctuation, has been long debated since 1866. A pH clue to understand the different mechanisms and redesign the criteria to normalize the capacity contribution is proposed. A tunable H+/Zn2+/Mn2+ charge storage system is elaborated for a realistic evaluation of ZMABs.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The large‐scale deployment of aqueous Zn‐ion batteries is hindered by Zn anode instability including surface corrosion, hydrogen gas evolution, and irregular Zn deposition. To tackle these ...challenges, a polyhydroxylated organic molecular additive, trehalose, is incorporated to refine the solvation structure and promote planar Zn deposition. Within solvation structure regions involving trehalose, the hydroxy groups participate in the reconstruction of hydrogen bond networks, which increases the overpotential for water decomposition reaction. Moreover, at the Zn metal–molecule interface, the chemisorption of trehalose onto the surface of the zinc anode enhances corrosion resistance and facilitates the deposition of zinc in a planar manner. The optimized electrolyte significantly improves Zn striping/plating reversibility and maintains stable potentials over 1600 h at 5 mA cm−2 with a cutoff capacity of 1 mA h cm−2 in symmetric cells. When combined with the MnO2 cathode, the assembled coin cell retains ≈89% of its capacity after 1000 cycles. This organic molecule additive, emphasizing the role of polyhydroxylated organic molecules in fine‐tuning solvation structures and anode/electrolyte interfaces, holds promise for enhancing various aqueous metal batteries.
Trehalose, a widely used moisturizer, preservative, and stabilizer in the food industry, is proven to be an effective electrolyte additive to the sulfite electrolyte for aqueous zinc ion battery. It optimizes the solvation structure by decreasing free water molecules and forming hydrogen bond networks. Trehalose also stabilizes the metal‐electrolyte interface through chemisorption, benefiting planar zinc deposition and suppressing dendrite growth.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The poor stability of the zinc‐metal anode is a main bottleneck for practical application of aqueous zinc‐ion batteries. Herein, a series of molecular sieves with various channel sizes are ...investigated as an electrolyte host to regulate the ionic environment of Zn2+ on the surface of the zinc anode and to realize separator‐free batteries. Based on the ZSM‐5 molecular sieve, a solid–liquid mixed electrolyte membrane is constructed to uniformize the transport of zinc ions and foster dendrite‐free Zn deposition. Side reactions can also be suppressed through tailoring the solvation sheath and restraining the activity of water molecules in electrolyte. A V2O5||ZSM‐5||Zn full cell shows significantly enhanced performance compared to cells using glass fiber separator. Specifically, it exhibits a high specific capacity of 300 mAh g−1, and a capacity retention of 98.67% after 1000 cycles and 82.67% after 3000 cycles at 1 A g−1. It is attested that zeolites (ZSM‐5, H‐β, and Bate) with channel sizes of 5–7 Å result in best cycle stability. Given the low cost and recyclability of the ZSM and its potent function, this work may further lower the cost and boost the industrial application of AZIBs.
Molecular‐sieves‐based electrolyte membranes are designed to regulate the activity of water, and inhibit dendrite growth and hydrogen evolution on the Zn anode, which greatly prolongs the cycle life of aqueous zinc‐ion batteries.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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