RESUMEN
P-type organic cathode materials typically exhibit high redox potentials and fast redox kinetics, presenting broad application prospects in aqueous zinc batteries (AZBs). However, most of the reported P-type organic cathode materials exhibit limited capacity (< 100 mAh g-1), which is attributable to the low mass content ratio of oxidation-reduction active functional groups in these materials. Herein, we report a high-capacity p-type organic material, 5,12-dihydro-5,6,11,12-tetraazatetracene (DHTAT), for aqueous zinc batteries. Both experiments and calculation indicate the charge storage of DHTAT involves the adsorption/ desorption of ClO4- on the -NH- group. Benefitting from the high mass content ratio of the -NH- group in DHATA molecule, the DHATA electrode demonstrates a remarkable capacity of 224 mAh g-1 at a current density of 50 mA g-1 with a stable voltage of 1.2 V. Notably, after 5000 cycles at a high current density of 5 A g-1, DHTAT retains 73% of its initial capacity, showing a promising cycling stability. In addition, DHTAT also has good low-temperature performance and can stably cycle at -40 °C for 4000 cycles at 1 A g-1, making it a competitive candidates cathode material for low-temperature batteries.
RESUMEN
Rechargeable aqueous zinc batteries are promising in next-generation sustainable energy storage. However, the low zinc (Zn) metal anode reversibility and utilization in aqueous electrolytes due to Zn corrosion and poor Zn2+ deposition kinetics significantly hinder the development of Zn-ion batteries. Here, a dual salt/dual solvent electrolyte composed of Zn(BF4)2/Zn(Ac)2 in water/TEGDME (tetraethylene glycol dimethyl ether) solvents to achieve reversible Zn anode at an ultrahigh depth of discharge (DOD) is developed. An "inner co-salt and outer co-solvent" synergistic effect in this unique dual salt/dual solvent system is revealed. Experimental results and theoretical calculations provide evidence that the ether co-solvent inhibits water activity by forming hydrogen bonding with the water and coordination effects with the proton in the outer Zn2+ solvation structure. Meanwhile, the anion of zinc acetate co-salt enters the inner Zn2+ solvation structure, thereby accelerating the desolvation kinetics. Strikingly, based on the electrolyte design, the zinc anode shows high reversibility at an ultrahigh utilization of 60% DOD with 99.80% Coulombic efficiency and 9.39 mAh cm-2 high capacity. The results far exceed the performance reported in electrolyte design work recently. The work provides fundamental insights into inner co-salt and outer co-solvent synergistic regulation in multifunctional electrolytes for reversible aqueous metal-ion batteries.
RESUMEN
Aqueous zinc-ion batteries hold great potentials for large-scale grid energy storage. However, the electrode corrosion, hydrogen evolution, and dendrite growth of Zn anode often lead to cell failure. Herein, N groups in Ti3C2Tx (NMXH) are introduced as interfacial layer through hydrothermal treatment of Ti3C2Tx with urea. The experimental analysis and density functional theory calculation indicate that N groups in Ti3C2Tx can homogenize electric field distribution, promote adsorption of Zn2+ on N groups, and strength interactions between N groups and Zn atoms on (002) plane. Thereby, the use of NMXH interfacial layer can effectively suppress the side reactions and realize uniform Zn deposition along the (002) plane. As a consequence, the NMXHâZn//Zn cell exhibits an ultralow nucleation overpotential (1 mA cm-2, 18.9 mV) and can stably operate for 1400 h at 1 mA cm-2 (1 mAh cm-2) and 110 h at 40 mA cm-2 (1 mAh cm-2). A full battery with V2O5 nanowires as cathode displays a discharge capacity of 219 mAh g-1 (1.0 A g-1), along with a decent rate capability and cyclability. The significant role of N groups reported in this work offers a promising avenue to improve the cycling stability of Zn anodes of aqueous zinc batteries.
RESUMEN
Aqueous zinc batteries (AZBs) with the advantages of safety, low cost, and sustainability are promising candidates for large-scale energy storage devices. However, the issues of interface side reactions and dendrite growth at the zinc metal anode (ZMA) significantly harm the cycling lifespan of AZBs. In this study, we designed a nano-molecular sieve additive, fullerenol (C60(OH)n), which possesses a surface rich in hydroxyl groups that can be uniformly dispersed in the aqueous solution, and captures free water in the electrolyte, thereby suppressing the occurrence of interfacial corrosion. Besides, fullerenol can be further reduced to fullerene (C60) on the surface of ZMA, holding a unique self-smoothing effect that can inhibit the growth of dendritic Zn. With the synergistic action of these two effects, the fullerenol-contained electrolyte (FE) enables dendrite-free ZMAs. The Zn-Ti half-cell using FE exhibits stable cycling over 2500 times at 5 mA cm-2 with an average Coulombic efficiency as high as 99.8 %. Additionally, the Zn-NaV3O8 cell using this electrolyte displays a capacity retention rate of 100 % after 1000 cycles at -20 °C. This work provides important insights into the molecular design of multifunctional electrolyte additives.
RESUMEN
Zinc metal is recognized as the most promising anode for aqueous energy storage but suffers from severe dendrite growth and poor reversibility. However, the coulombic efficiency lacks specificity for zinc dendrite growth, particularly in Zn||Zn symmetric cells. Herein, a novel indicator (fD) based on the characteristic crystallization peaks is proposed to evaluate the growth and distribution of zinc dendrites. As a proof of concept, triethylenetetramine (TETA) is adopted as an electrolyte additive to manipulate the zinc flux for uniform deposition, with a corroborating low fD value. A highly durable zinc symmetric cell is achieved, lasting over 2500 h at 10 mA cm-2 and 400 h at a large discharge of depth (10 mA cm-2, 10 mAh cm-2). Supported by the low fD value, the Zn||TETA-ZnSO4||MnO2 batteries overcome the sudden short circuit and fast capacity fading. The study provides a feasible method to evaluate zinc dendrites and sheds light on the design of highly reversible zinc anodes.
RESUMEN
Interfacial instability within aqueous zinc batteries (AZBs) spurs technical obstacles including parasitic side reactions and dendrite failure to reach the practical application standards. Here, an interfacial engineering is showcased by employing a bio- derived zincophilic macromolecule as the electrolyte additive (0.037 wt%), which features a long-chain configuration with laterally distributed hydroxyl and sulfate anion groups, and has the propensity to remodel the electric double layer of Zn anodes. Tailored Zn2+-rich compact layer is the result of their adaptive adsorption that effectively homogenizes the interfacial concentration field, while enabling a hybrid nucleation and growth mode characterized as nuclei-rich and space-confined dense plating. Further resonated with curbed corrosion and by-products, a dendrite-free deposition morphology is achieved. Consequently, the macromolecule-modified zinc anode delivers over 1250 times of reversible plating/stripping at a practical area capacity of 5 mAh cm-2, as well as a high zinc utilization rate of 85%. The Zn//NH4V4O10 pouch cell with the maximum capacity of 1.02 Ah can be steadily operated at 71.4 mA g-1 (0.25 C) with 98.7% capacity retained after 50 cycles, which demonstrates the scale-up capability and highlights a "low input and high return" interfacial strategy toward practical AZBs.
RESUMEN
The value of aqueous zinc-ion rechargeable batteries is held back by the degradation of the Zn metal anode with repeated cycling. While raising the operating current density is shown to alleviate this anode degradation, such high cycling rates are not compatible with full cells, as they cause Zn-host cathodes to undergo capacity decay. A simple approach that improves anode performance while using more modest cathode-compatible current densities is required. This work reports reversible planar Zn deposition under cathode-compatible current densities can instead be achieved by applying external pressure to the cell. Employing multiscale characterization, this work illustrates how cycling under pressure results in denser and more uniform Zn deposition, analogous to that achieved under high cycling rates, even at low areal current densities of 1 to 10 mA cm-2. Microstructural mechanical measurements reveal that Zn structures plated under lower current densities are particularly susceptible to pressure-induced compression. The ability to achieve planar Zn plating at cathode-compatible current densities holds significant promise for enabling high-capacity Zn-ion battery full cells.
RESUMEN
Regulating the electric double layer (EDL) structure of the zinc metal anode by using electrolyte additives is an efficient way to suppress interface side reactions and facilitate uniform zinc deposition. Nevertheless, there are no reports investigating the proactive design of EDL-regulating additives before the start of experiments. Herein, a functional group assembly strategy is proposed to design electrolyte additives for modulating the EDL, thereby realizing a long-lasting zinc metal anode. Specifically, by screening ten common functional groups, N, N-dimethyl-1H-imidazole-1-sulfonamide (IS) is designed by assembling an imidazole group, characterized by its high adsorption capability on the zinc anode, and a sulfone group, which exhibits strong binding with Zn2+ ions. Benefiting from the adsorption functionalization of the imidazole group, the IS molecules occupy the position of H2O in the inner Helmholtz layer of the EDL, forming a molecular protective layer to inhibit H2O-induced side reactions. Meanwhile, the sulfone group in IS, acting as a binding site to Zn2+, promotes the de-solvation of Zn2+ ions, facilitating compact zinc deposition. Consequently, the utilization of IS significantly extending the cycling stability of Zn||Zn and Zn||NaV3O8 â 1.5H2O full cell. This study offers an innovative approach to the design of EDL regulators for high-performance zinc metal batteries.
RESUMEN
Rechargeable aqueous-zinc ion batteries (AZIB) have notable benefits in terms of high safety and low cost. Nevertheless, the challenges, such as dendrite growth, zinc anode corrosion, and hydrogen evolution reaction, impede its practical implementation. Hence, this study proposes the introduction of an economical ErCl3 electrolyte additive to stabilize the Zn anode surface and address the aforementioned issues. The introduced Er3+ will cover the raised zinc dendrite surface and weaken the "tip effect" on the surface of the zinc anode via the "electrostatic shielding" effect. Simultaneously, the introduced Cl- can reduce the polarization of the zinc anode. Due to the synergistic effect of Er3+ and Cl-, the zinc anode corrosion, dendrite growth and hydrogen evolution have been efficiently inhibited. As a result, the Zn||Zn-symmetric battery using ErCl3 additive can stably cycle for 1100 h at 1 mA cm-2, 1 mAh cm-2, and exhibit a high average coulomb efficiency (99.2 %). Meanwhile, Zn||MnO2 full battery based on ErCl3-added electrolyte also demonstrates a high reversible capacity of 157.1 mAh/g after 500 cycles. Obviously, the capacity decay rate of the full battery is also improved, only 0.113 % per cycle. This study offers a straightforward and economically efficient method for stabilizing the zinc anode and realizing high-performance AZIBs.
RESUMEN
The compact design of an environmentally adaptive battery and effectors forms the foundation for wearable electronics capable of time-resolved, long-term signal monitoring. Herein, we present a one-body strategy that utilizes a hydrogel as the ionic conductive medium for both flexible aqueous zinc-ion batteries and wearable strain sensors. The poly(vinyl alcohol) hydrogel network incorporates nano-SiO2 and cellulose nanofibers (referred to as PSC) in an ethylene glycol/water mixed solvent, balancing the mechanical properties (tensile strength of 6 MPa) and ionic diffusivity at -20 °C (2 orders of magnitude higher than 2 M ZnCl2 electrolyte). Meanwhile, cathode lattice breathing during the solvated Zn2+ intercalation and dendritic Zn protrusion at the anode interface are mitigated. Besides the robust cyclability of the Znâ¥PSCâ¥V2O5 prototype within a wide temperature range (from -20 to 80 °C), this microdevice seamlessly integrates a zinc-ion battery with a strain sensor, enabling precise monitoring of the muscle response during dynamic body movement. By employing transmission-mode operando XRD, the self-powered sensor accurately documents the real-time phasic evolution of the layered cathode and synchronized strain change induced by Zn deposition, which presents a feasible solution of health monitoring by the miniaturized electronics.
RESUMEN
Rechargeable aqueous zinc batteries are promising but hindered by unfavorable dendrite growth and side reactions on zinc anodes. In this study, we demonstrate a fast melting-solidification approach for effectively converting commercial Zn foils into single (002)-textured Zn featuring millimeter-sized grains. The melting process eliminates initial texture, residual stress, and grain size variations in diverse commercial Zn foils, guaranteeing the uniformity of commercial Zn foils into single (002)-textured Zn. The single (002)-texture ensures large-scale epitaxial and dense Zn deposition, while the reduction in grain boundaries significantly minimizes intergranular reactions. These features enable large grain single (002)-textured Zn shows planar and dense Zn deposition under harsh conditions (100â mA cm-2, 100â mAh cm-2), impressive reversibility in Zn||Zn symmetric cell (3280â h under 1â mA cm-2, 830â h under 10â mAh cm-2), and long cycling stability over 180â h with a high depth of discharge value of 75 %. This study successfully addresses the issue of uncontrollable texture formation in Zn foils following routine annealing treatments with temperatures below the Zn melting point. The findings of this study establish a highly efficient strategy for fabricating highly reversible single (002)-textured Zn anodes.
RESUMEN
Rechargeable aqueous zinc batteries are potential candidates for sustainable energy storage systems at a grid scale, owing to their high safety and low cost. However, the existing cathode chemistries exhibit restricted energy density, which hinders their extensive applications. Here, a tellurium redox-amphoteric conversion cathode chemistry is presented for aqueous zinc batteries, which delivers a specific capacity of 1223.9 mAh gTe -1 and a high energy density of 1028.0 Wh kgTe -1. A highly concentrated electrolyte (30 mol kg-1 ZnCl2) is revealed crucial for initiating the Te redox-amphoteric conversion as it suppresses the H2O reactivity and inhibits undesirable hydrolysis of the Te4+ product. By carrying out multiple operando/ex situ characterizations, the reversible six-electron Te2-/Te0/Te4+ conversion with TeCl4 is identified as the fully charged product and ZnTe as the fully discharged product. This finding not only enriches the conversion-type battery chemistries but also establishes a critical step in exploring redox-amphoteric materials for aqueous zinc batteries and beyond.
RESUMEN
Manganese dioxide (MnO2) is an attractive cathode material for aqueous zinc batteries (AZBs) owing to its environmental benignity, low cost, high operating voltage, and high theoretical capacity. However, the severe dissolution of Mn2+ leads to rapid capacity decay. Herein, a self-assembled layer of amino-propyl phosphonic acid (AEPA) on the MnO2 surface, which significantly improves its cycle performance is successfully modified. Specifically, AEPA can be firmly attached to MnO2 through a strong chemical bond, forming a hydrophobic, and uniform organic coating layer with a few nanometers thickness. This coating layer can significantly inhibit the dissolution of Mn2+ by avoiding the direct contact between the electrolyte and cathode, thus enhancing the structural integrity and redox reversibility of MnO2. As a result, the MnO2@AEPA cathode achieves a high reversible capacity of 223 mAh g-1 at 0.5 A g-1 and a high capacity retention of 97% after 1700 cycles at 1 A g-1. This work provides new insights in developing stable Mn-based cathodes for aqueous batteries.
RESUMEN
Vanadium trioxide (V6 O13 ) cathode has recently aroused intensive interest for aqueous zinc-ion batteries (AZIBs) due to their structural and electrochemical diversities. However, it undergoes sluggish reaction kinetics and significant capacity decay during prolonged cycling. Herein, an oxygen-vacancy-reinforced heterojunction in V6 O13- x /reduced graphene oxide (rGO) cathode is designed through electrostatic assembly and annealing strategy. The abundant oxygen vacancies existing in V6 O13- x weaken the electrostatic attraction with the inserted Zn2+ ; the external electric field constructed by the heterointerfaces between V6 O13- x and rGO provides additional built-in driving force for Zn2+ migration; the oxygen-vacancy-enriched V6 O13- x highly dispersed on rGO fabricates the interconnected conductive network, which achieves rapid Zn2+ migration from heterointerfaces to lattice. Consequently, the obtained 2D heterostructure exhibits a remarkable capacity of 424.5 mAh g-1 at 0.1 A g-1 , and a stable capacity retention (96% after 5800 cycles) at the fast discharge rate of 10 A g-1 . Besides, a flexible pouch-type AZIB with real-life practicability is fabricated, which can successfully power commercial products, and maintain stable zinc-ion storage performances even under bending, heavy strikes, and pressure condition. A series of quantitative investigation of pouch batteries demonstrates the possibility of pushing pouch-type AZIBs to realistic energy storage market.
RESUMEN
Aqueous zinc electrolytes offer the potential for cheaper rechargeable batteries due to their safe compatibility with the high capacity metal anode; yet, they are stymied by irregular zinc deposition and consequent dendrite growth. Suppressing dendrite formation by tailoring the electrolyte is a proven approach from lithium batteries; yet, the underlying mechanistic understanding that guides such tailoring does not necessarily directly translate from one system to the other. Here, it is shown that the electrostatic shielding mechanism, a fundamental concept in electrolyte engineering for stable metal anodes, has different consequences for the plating morphology in aqueous zinc batteries. Operando electrochemical transmission electron microscopy is used to directly observe the zinc nucleation and growth under different electrolyte compositions and reveal that electrostatic shielding additive suppresses dendrites by inhibiting secondary zinc nucleation along the (100) edges of existing primary deposits and encouraging preferential deposition on the (002) faces, leading to a dense and block-like zinc morphology. The strong influence of the crystallography of Zn on the electrostatic shielding mechanism is further confirmed with Zn||Ti cells and density functional theory modeling. This work demonstrates the importance of considering the unique aspects of the aqueous zinc battery system when using concepts from other battery chemistries.
RESUMEN
The essential virtues of aqueous zinc battery chemistry stem from the energy-dense zinc metal anode and mild aqueous electrolytes. Yet, their incompatibility - as exposed by zinc's corrosion and associated dendrite problem - poses a challenge to achieving improved cycle life under practically relevant parameters. While electrolyte additives are a scalable strategy, additives that can function at low volume concentrations remain elusive. Here, through screening alkanol and alkanediol chemistries, 1,2-butanediol and pentanediol are unveiled as highly potent additives, which operate at a practical 1 volume% concentration owing to their ability to furnish dynamic solid-electrolyte interphase through pronounced interfacial filming. This unique mechanistic action renders effective corrosion and dendrite mitigation, resulting in up to five to twenty-fold zinc cyclability enhancement with a high Coulombic efficiency (up to 99.9%) and improved full-cell performance under demanding conditions, including at elevated temperatures. A machine learning-based analysis is presented to rationalize the additive performance relative to critical physicochemical descriptors, which can pave the way for a rational approach to efficient additive discoveries.
RESUMEN
Aqueous highly concentrated electrolytes (AHCEs) have recently emerged as an innovative strategy to enhance the cycling stability of aqueous Zinc (Zn) batteries (AZB). Particularly, thanks to high Zn Chloride (ZnCl2 ) solubility in water, AHCEs based on ZnCl2 feature remarkable Zn anode stability. However, due to their inherently acidic pH and Cl- anion reactivity, these electrolytes face compatibility challenges with other battery components. Here, an aqueous eutectic electrolyte (AEE) based on Brønsted-Lowry concept is reported-allowing the usage of cheap and abundant salts, ZnCl2, and sodium acetate (NaAc). The reported, pH buffered, AEE displays a higher coordination of water at an even lower salt concentration, by simply balancing the acceptor-donor Hâbonding. This results in impressive improvement of electrolyte properties such as high electrochemical stability, high transport properties and low glass transition temperature. The developed AEE displays higher compatibility with vanadium oxide-based cathode with a 50% increase in capacity retention in comparison to sat. ZnCl2 . More importantly, the pH buffered AEE solves the incompatibility issues of ZnCl2 toward commonly used aluminium (Al) current collector as well as cellulose separator. This work presents an efficient, simple, and low-cost strategy for the development of aqueous electrolytes for the practical application of Zn batteries.
RESUMEN
One effective solution to inhibit side reactions and Zn dendrite growth in aqueous Zn-ion batteries is to add a cosolvent into the Zn(CF3SO3)2 electrolyte, which has the potential to form a robust solid electrolyte interface composed of ZnF2 and ZnS. Nevertheless, there is still a lack of discussion on a convenient selection method for cosolvents, which can directly reflect the interactions between solvent and solute to rationally design the electrolyte solvation structure. Herein, logP, where P is the octanol-water partition coefficient, a general parameter to describe the hydrophilicity and lipophilicity of chemicals, is proposed as a standard for selecting cosolvents for Zn(CF3SO3)2 electrolyte, which is demonstrated by testing seven different types of solvents. The solvent with a logP value similar to that of the salt anion CF3SO3- can interact with CF3SO3-, Zn2+, and H2O, leading to a reconstruction of the electrolyte solvation structure. To prove the concept, methyl acetate (MA) is demonstrated as an example due to its similar logP value to that of CF3SO3-. Both the experimental and theoretical results illustrate that MA molecules not only enter into the solvation shell of CF3SO3- but also coordinate with Zn2+ or H2O, forming an MA and CF3SO3- involved core-shell solvation structure. The special solvation structure reduces H2O activity and contributes to forming an anion-induced ZnCO3-ZnF2-rich solid electrolyte interface. As a result, the Zn||Zn cell and Zn||NaV3O8·1.5H2O cell with MA-involved electrolyte exhibit superior performances to that with the MA-free electrolyte. This work provides an insight into electrolyte design via salt anion chemistry for high-performance Zn batteries.
RESUMEN
Mildly acidic aqueous zinc batteries (AZBs) have attracted tremendous attention for grid storage applications with the expectation to tackle the issues of Li-ion batteries on high cost and poor safety. However, the performance, particularly energy density and cycle stability of AZBs are still unsatisfactory when compared with LIBs. To help the development of AZBs, a lot of effort have been made to understand the battery reaction mechanisms and precedent microscopic and spectroscopic analyses have shown flake-like large particles of zinc hydroxide sulfate (ZHS) and its analogues formed on the surfaces of cathodes and anodes in sulfate and other electrolyte systems during cycling. However, because of the complexity of the thermodynamics and kinetics of aqueous reactions to understand different battery conditions, controversies still exist. This article will review the roles of ZHS discussed in recent representative references aiming to shine light on the fundamental mechanisms of AZBs and pave ways to further improve the battery performance.
RESUMEN
Aqueous zinc-ion batteries (AZIBs) offer promising prospects for large-scale energy storage due to their inherent abundance and safety features. However, the growth of zinc dendrites remains a primary obstacle to the practical industrialization of AZIBs, especially under harsh conditions of high current densities and elevated temperatures. To address this issue, a Janus separator with an exceptionally ultrathin thickness of 29 µm is developed. This Janus separator features the bacterial cellulose (BC) layer on one side and Ag nanowires/bacterial cellulose (AgNWs/BC) layer on the other side. High zincophilic property and excellent electric/thermal conductivity of AgNWs make them ideal for serving as an ion pump to accelerate Zn2+ transport in the electrolyte, resulting in greatly improved Zn2+ conductivity, deposition of homogeneous Zn nuclei, and dendrite-free Zn. Consequently, the Zn||Zn symmetrical cells with the Janus separator exhibit a stable cycle life of over 1000 h under 80 mA cm-2 and are sustained for over 600 h at 10 mA cm-2 under 50 °C. Further, the Janus separator enables excellent cycling stability in AZIBs, aqueous zinc-ion capacitors (AZICs), and scaled-up flexible soft-packaged batteries. This study demonstrates the potential of functional separators in promoting the application of aqueous zinc batteries, particularly under harsh conditions.