Tuning Zn-ion de-solvation chemistry with trace amount of additive towards stable Aqueous Zn anodes.

Aqueous Zn-ion batteries (AZIBs) have attracted widespread attention due to their intrinsic safety, cost-effectiveness. However, active H2O in the solvated ions [Zn(H2O)6]2+ continuously migrate to the Zn surface to trigger hydrogen evolution reaction (HER) and accelerate Zn corrosion. Herein, Zn dendrites and the related by-products have been successfully inhibited by using trace amounts of Nitrilotriacetic acid (NTA). Theoretical research indicates that two carboxyl groups of NTA molecule strongly anchored on the Zn surface and exposed another carboxyl group outside. Due to the violent interaction of carboxyl groups of NTA with H2O, the de-solvation energy barrier of solvated Zn2+ ([Zn(H2O)6]2+) on the Zn surface was obviously decreased, inhibit the active water splitting. Meanwhile, the preferential adsorption of NTA on the Zn surface increases the thickness of electric double layer EDL and provides a buffer layer to hinder the dendrite growth. Using 0.04 M NTA as additives in 2.0 M ZnSO4 electrolyte, the cycling lifespan of both Zn||Zn symmetric and Zn||MnO2 full cells is markedly prolonged. This study provides certain perspectives for trace amounts of electrolyte additives to satisfy the demand of long-cycle life AZIBs.

Toward the Rechargeable Aqueous Zinc Ion Batteries with Improved Overall Performance: Electrolyte with Surface Adsorptive Additive.

Aqueous zinc-ion batteries (AZIBs) with slightly acidic electrolytes process advantages such as high safety, competitive cost, and satisfactory electrochemical performance. However, the failure behaviors of both electrodes, regarding zinc dendrite growth, interfacial parasitic reactions, and the collapse of cathode materials hinder the practical application of ZIBs. To alleviate the issues of both anode and cathode at the same time, D-xylose (DX) is introduced to the electrolyte as a multifunctional additive. As a result, the side reaction of the anode is suppressed and the metallic deposition behavior is regulated due to the hydrogen bonding network reconstruction and preferential surface adsorption of DX; for the MnO2 cathode, the DX adsorption can help the interfacial charge transfer and increase the reactive sites. Benefiting from these merits, DX-optimized Zn//Zn battery displays reveal a prolonged lifespan of 6912 h and an ultra-high cumulative capacity of 17.28 Ah cm-2 at 5 mA cm-2. With the function of water reactivity suppression, the Coulombic efficiency reaches 99.91% at 2 mA cm-2; the Zn||MnO2 full batteries exhibit excellent cyclability over 2000 cycles at 5C with an increased capacity of 118.9 mAh g-1, indicating the dual functions to both of the electrodes for AZIBs.

High-Capacity Zinc Anode Enabled by a Recyclable Biomass Bamboo Membrane Separator.

Aqueous zinc ion batteries have gained attention as viable energy storage systems, yet the occurrence of detrimental side reactions and Zn dendrite formation undermines the efficiency of Zn anodes. Controlling water activity have proven to be an effective strategy in mitigating these challenges. However, strategies such as electrolyte design and electrode protection layer show weakness to varying degrees. Here, a new oxygen-functionalized biomass bamboo membrane separator (denoted as BM) is proposed to restrain the activity of water molecules. This BM separator features a unique, multi-tiered 2D interlayer that facilitates rapid ion diffusion. Additionally, the oxygen functional groups of the BM separator can form hydrogen bonds with water molecules, effectively transforming water molecules from a free state to a bound state. Consequently, the Zn/Zn asymmetric coin cell using BM can work at the ultrahigh rate and capacity of 30 mA cm-2 and 30 mAh cm-2 for more than 80 h while its counterparts using glass fiber can barely work. Moreover, full cells using BM separator exhibited a capacity retention of 89.7% after 1000 cycles at 10 A g-1. This study reveals the important influence of water-limited activity on Zn anode protection and provides an avenue for the design of novel separator.

A Synergistically Regulated Cathode/Electrolyte Interphase With High Stability and Rapid Zn2+ Migration Toward Advanced Flexible Zinc-Ion Batteries.

Na3V2(PO4)3(NVP), as a representative sodium superionic conductor with a stable polyanion framework, is considered a cathode candidate for aqueous zinc-ion batteries attributed to their high discharge platform and open 3D structure. Nevertheless, the structural stability of NVP and the cathode-electrolyte interphase (CEI) layer formed on NVP can be deteriorated by the aqueous electrolyte to a certain extent, which will result in slow Zn2+ migration. To solve these problems, doping Si elements to NVP and adding sodium acetate (NaAc) to the electrolyte are utilized as a synergistic regulation route to enable a highly stable  CEI with rapid Zn2+ migration. In this regard, Ac- competitively takes part in the solvation structure of Zn2+ in aqueous electrolyte, weakening the interaction between water and Zn2+, and meanwhile a highly stable CEI is formed to avoid structural damage and enable rapid Zn2+ migration. The NVPS/C@rGO electrode exhibits a notable capacity of 115.5 mAh g-1 at a current density of 50 mA g-1 in the mixed electrolyte (3 M ZnOTF2+3 M NaAc). Eventually, a collapsible "sandwich" soft pack battery is designed and fabricated and can be used to power small fans and LEDs, which proves the practical application of aqueous zinc-ion batteries in flexible batteries.

Constructing Quasi-single Ion Conductors by a ß-Cyclodextrin Polymer to Stabilize Zn Anode.

Aqueous Zn-ion batteries (AZIBs) are promising for the next-generation large-scale energy storage. However, the Zn anode remains facing challenges. Here, we report a cyclodextrin polymer (P-CD) to construct quasi-single ion conductor for coating and protecting Zn anodes. The P-CD coating layer inhibited the corrosion of Zn anode and prevented the side reaction of metal anodes. More important is that the cyclodextrin units enabled the trapping of anions through host-guest interactions and hydrogen bonds, forming a quasi-single ion conductor that elevated the Zn ion transference number (from 0.31 to 0.68), suppressed the formation of space charge regions and hence stabilized the plating/striping of Zn ions. As a result, the Zn//Zn symmetric cells coated with P-CD achieved a 70.6 times improvement in cycle life at high current densities of 10 mA cm-2 with 10 mAh cm-2. Importantly, the Zn//K1.1V3O8 (KVO) full-cells with high mass loading of cathode materials and low N/P ratio of 1.46 reached the capacity retention of 94.5% after 1000 cycles at 10 A g-1; while the cell without coating failed only after 230 cycles. These results provide novel perspective into the control of solid-electrolyte interfaces for stabilizing Zn anode and offer a practical strategy to improve AZIBs.

Seed-Assisted Reversible Dissolution/Deposition of MnO2 for Long-Cyclic and Green Aqueous Zinc-Ion Batteries.

Manganese oxide (MnO2) based aqueous zinc-ion batteries (AZIBs) are considered to be a promising battery for grid-scale energy storage. However, they usually suffer from the great challenge of capacity attenuation due to Mn dissolution and irreversible structural transformation. Herein, full use of the shortcomings is made to design high-performance cathode-free AZIBs. Manganese-based Prussian blue analog (Mn-PBA) is selected as a seed layer to provide a stable MnO2 electrodeposition surface. Thanks to the large specific surface area and manganophilic nature of Mn-PBA, the deposition/dissolution kinetics between Mn2+ and MnO2 are significantly enhanced. Systematic studies revealed the mechanism of MnO2 deposition-dissolution related to the reversible transformation of manganese oxide hydroxide and zinc hydroxide sulfate hydrate. Based on this, the developed cathode-free AZIBs exhibit outstanding rate performance (with a specific capacity of 273.7 mAh g-1 at 1 A g-1) and extraordinary cycle stability (maintaining a specific capacity of 52.3 mAh g-1 after 50 000 cycles at 20 A g-1). Furthermore, the AZIBs with non-toxic, biocompatible materials can be directly discarded after use, without causing pollution to the environment, which is expected to help achieve the sustainable development goals.

Selection of Negative Charged Acidic Polar Additives to Regulate Electric Double Layer for Stable Zinc Ion Battery.

Zinc-ion batteries are promising for large-scale electrochemical energy storage systems, which still suffer from interfacial issues, e.g., hydrogen evolution side reaction (HER), self-corrosion, and uncontrollable dendritic Zn electrodeposition. Although the regulation of electric double layer (EDL) has been verified for interfacial issues, the principle to select the additive as the regulator is still misted. Here, several typical amino acids with different characteristics were examined to reveal the interfacial behaviors in regulated EDL on the Zn anode. Negative charged acidic polarity (NCAP) has been unveiled as the guideline for selecting additive to reconstruct EDL with an inner zincophilic H2O-poor layer and to replace H2O molecules of hydrated Zn2+ with NCAP glutamate. Taking the synergistic effects of EDL regulation, the uncontrollable interface is significantly stabilized from the suppressed HER and anti-self-corrosion with uniform electrodeposition. Consequently, by adding NCAP glutamate, a high average Coulombic efficiency of 99.83% of Zn metal is achieved in Zn|Cu asymmetrical cell for over 2000 cycles, and NH4V4O10|Zn full cell exhibits a high-capacity retention of 82.1% after 3000 cycles at 2 A g-1. Recapitulating, the NCAP principle posted here can quicken the design of trailblazing electrolyte additives for aqueous Zn-based electrochemical energy storage systems.

Mitigating Zn Dendrite Growth and Enhancing the Utilization of Zn Electrode in Aqueous Zn-Ion Batteries.

In spite of extensive research and appreciable progress, in aqueous zinc-ion batteries, Zn metal anode is struggling with low Zn utility and poor cycling stability. In this study, a 3D "electrochemical welding" composite electrode is designed by introduction of ZnO/C nanofibers film to copper foils as an anode according to pre-electrodeposition active Zn (Zn@ZnO/C-Cu). The flow of Zn2+ through carbon fiber layer is regulated by zincophilic ZnO, promoting homogeneous diffusion of Zn2+ to Cu foil. In subsequent Zn deposition/stripping processes, the hydrophobicity of ZnO/C fiber layer reduces water at the interface of Zn@ZnO/C-Cu and results in uniform electric field significant suppressing growth of Zn dendritic and side reactions. Thus, pre-electrodeposition active Zn electrochemical welds ZnO/C nanofibers and Cu foil collectively provide stable charge/electron transfer and stripping/plating of Zn with low polarization and excellent cycling performance. The assembled symmetrical batteries exhibit stable cycling performance for over 470 h under 20% utilization of Zn at 5 mA cm-2, and an average coulombic efficiency of 99.9% at low negative/positive capacity ratio (N/P = 1) after 1000 cycles in the Zn@ZnO/C-Cu||Na2V6O16·1.5H2O full cell.

Stabilizing Zinc Anode through Ion Selection Sieving for Aqueous Zn-Ion Batteries.

Uncontrollable dendrite growth and corrosion induced by reactive water molecules and sulfate ions (SO42-) seriously hindered the practical application of aqueous zinc ion batteries (AZIBs). Here we construct artificial solid electrolyte interfaces (SEIs) realized by sodium and calcium bentonite with a layered structure anchored to anodes (NB@Zn and CB@Zn). This artificial SEI layer functioning as a protective coating to isolate activated water molecules, provides high-speed transport channels for Zn2+, and serves as an ionic sieve to repel negatively charged anions while attracting positively charged cations. The theoretical results show that the bentonite electrodes exhibit a higher binding energy for Zn2+. This demonstrates that the bentonite protective layer enhances the Zn-ion deposition kinetics. Consequently, the NB@Zn//MnO2 and CB@Zn//MnO2 full-battery capacities are 96.7 and 70.4 mAh g-1 at 2.0 A g-1 after 1000 cycles, respectively. This study aims to stabilize Zn anodes and improve the electrochemical performance of AZIBs by ion-selection sieving.

Noncovalent Interactions-Driven Self-Assembly of Polyanionic Additive for Long Anti-Calendar Aging and High-Rate Zinc Metal Batteries.

Zinc anodes of zinc metal batteries suffer from unsatisfactory plating/striping reversibility due to interfacial parasitic reactions and poor Zn2+ mass transfer kinetics. Herein, methoxy polyethylene glycol-phosphate (mPEG-P) is introduced as an electrolyte additive to achieve long anti-calendar aging and high-rate capabilities. The polyanionic of mPEG-P self-assembles via noncovalent-interactions on electrode surface to form polyether-based cation channels and in situ organic-inorganic hybrid solid electrolyte interface layer, which ensure rapid Zn2+ mass transfer and suppresses interfacial parasitic reactions, realizing outstanding cycling/calendar aging stability. As a result, the Zn//Zn symmetric cells with mPEG-P present long lifespans over 9000 and 2500 cycles at ultrahigh current densities of 120 and 200 mA cm-2, respectively. Besides, the coulombic efficiency (CE) of the Zn//Cu cell with mPEG-P additive (88.21%) is much higher than that of the cell (36.4%) at the initial cycle after the 15-day calendar aging treatment, presenting excellent anti-static corrosion performance. Furthermore, after 20-day aging, the Zn//MnO2 cell exhibits a superior capacity retention of 89% compared with that of the cell without mPEG-P (28%) after 150 cycles. This study provides a promising avenue for boosting the development of high efficiency and durable metallic zinc based stationary energy storage system.

Additive Manufacturing of Grid Reservoir-Integrated Anodes for Dendrite-Free, Safe, and Ultra-Low Voltage Zinc-Ion Batteries.

This work reports a novel 3D printed grid reservoir-integrated mesoporous carbon coordinated silicon oxycarbide hybrid composite (3DP-MPC-SiOC) to establish the zincophile interphase for controlling the dendrite formation. The customized 3D printed grid patterned structure inhibits Zn dendrite growth and achieves long-term stability with reduced voltage polarization due to homogeneous electric field distribution. The hybrid composite consisting of SiOC interpenetrated within carbon constructs a high zinc nucleation interphase, hence promoting uniform Zn2+ deposition and enhancing ionic diffusion with dendrite-free growth and a reduced nucleation energy barrier. As a result, the 3DP-MPC-SiOC@Zn symmetrical cell affords a highly reversible Zn plating/stripping and dendrite-free structure over 198 h with an ultra-low voltage polarization. These inspiring performances endow the 3DP anode with a 3DP-VO cathode as a full battery, which shows a retention capacity of 78.8 mAh g-1 (Coulombic efficiency: 94.04%) at 0.1 A g-1 and a large energy density of 41 Wh kg-1 at a power density of 1.2 W kg-1 (based on the total mass of electrode) after 120 cycles. This newly developed 3D printing of hybrid composite as an electrode is straightforward and scalable and provides a novel concept for realizing dendrite-free and stable rechargeable Zn-ion batteries.

Surface engineering of zinc plate by self-growth three-dimensional-interconnected zinc silicate nanosheets effectively guiding the deposition of zinc ion for aqueous Zn metal battery.

Among battery technologies, aqueous zinc ion batteries (AZIBs) have hit between the eyes in the next generation of extensive energy storage devices due to their outstanding superiority. The main problem that currently restricts the development of AZIBs is how to obtain stable Zn anodes. In this study, taking the improvement of a series of problems caused by the physically attached artificial interfacial layer on Zn anode as a starting point, a nanosheet morphology of ZnSiO3 (denoted as ZnSi) is constructed by self-growth on Zn foil (Zn@ZnSi) by a simple hydrothermal reaction. The ZnSi nano-interfacial layer effectively slices the surface of the Zn foil into individual microscopic interfacial layers, constructing abundant pores. The nanosheets of Zn@ZnSi construct rich nanoscale Zn2+ transport channels, which provide higher electron and ion transport paths, thus achieving the effect of effectively homogenizing the electric field distribution and decreasing the local current density. Thanks to its inherent and structural properties, the Zn@ZnSi anode has a high specific capacity and good cycling stability compared with the Zn electrode. The lifetime of the Zn@ZnSi//Zn@ZnSi symmetric cell is much higher than that of the Zn//Zn symmetric cell at 1 mA cm-2. The capacity of the Zn@ZnSi//NH4V4O10 full cell can still reach 98 mAh g-1 after 1000 cycles at 1 A/g. The low-cost and scalable synthesis of ZnSi nano-interfacial layer on Zn is expected to provide new perspectives on interfacial engineering for Zn anodic protection.

Hofmeister Effects in Supramolecular Chemistry for Anion-Modulation to Stabilize Zn Anode.

Aqueous Zn-ion batteries (AZIBs) are considered as promising candidates for the next-generation large-scale energy storage, which, however, is facing the challenge of instable Zn anodes. The anion is pivotal in the stability of anodes, which are not being paid enough attention to. Herein, the modulation of anions is reported using the Hofmeister series in supramolecular chemistry to boost the stability of Zn anodes. It is found that the right-side anions in the Hofmeister series (e.g., OTf-) can enhance the Zn2+ transference number, increase the Coulombic efficiency, facilitate uniform Zn deposition, reduce the freezing point of electrolytes, and thereby stabilize the Zn anodes. More importantly, the right-side anions can form strong interaction with ß-cyclodextrin (ß-CD) compared to the left-side anions, and hence the addition of ß-CD can further enhance the stability of Zn anodes in OTf--based electrolytes, showing enhancement of cycling lifespan in the Zn//Zn symmetric cells more than 45.5 times with ß-CD compared with those without ß-CD. On the contrary, the left-side anions show worse rate performance after the addition of ß-CD. These results provide an effective and novel approach for choosing anions and matching additives to stabilize the anodes and achieve high-performance AZIBs through the Hofmeister effect.

Boosting the Zn2+ storage capacity of MoO3 nanoribbons by modulating the electrons spin states of Mo via Ni doping.

Aqueous zinc-ion batteries (AZIBs) have received considerable potential for their affordability and high reliability. Among potential cathodes, α-MoO3 stands out due to its layered structure aligned with the (010) plane, offering extensive ionic insertion channels for enhanced charge storage. However, its limited electrochemical activity and poor Zn2+ transport kinetics present significant challenges for its deployment in energy storage devices. To overcome these limitations, we introduce a new strategy by doping α-MoO3 with Ni (Ni-MoO3), tuning the electron spin states of Mo. Thus modification can activate the reactivity of Ni-MoO3 towards Zn2+ storage and weaken the interaction between Ni-MoO3 and intercalated Zn2+, thereby accelerating the Zn2+ transport and storage. Consequently, the electrochemical properties of Ni-MoO3 significantly surpass those of pure MoO3, demonstrating a specific capacity of 258 mAh g-1 at 1 A g-1 and outstanding rate performance (120 mAh g-1 at 10 A g-1). After 1000 cycles at 8 A g-1, it retains 76 % of the initial capacity, with an energy density of 154.4 Wh kg-1 and a power density of 11.2 kW kg-1. This work proves that the modulation of electron spin states in cathode materials via metal ion doping can effectively boost their capacity and cycling durability.

Accelerated and Guided Zn2+ Diffusion via Polarized Interface Engineering Toward High Performance Wearable Zinc-Ion Batteries.

Rechargeable aqueous Zn-ion batteries (ZIBs) are considered as a new energy storage device for wearable electronic equipment. Nowadays, dendrite growth and uneven deposition of zinc have been the principal problems to suppress the development of high-performance wearable zinc-ion batteries. Herein, a perovskite material of LaAlO3 nanoparticle has been applied for interface engineering and zinc anode protection. By adjusting transport channels and accelerating the Zn2+ diffusion, the hydrogen evolution reaction potential is improved, and electric field distribution on the Zn electrode surface is regulated to navigate the fast and uniform deposition of Zn2+. As a proof of demonstration, the assembled LAO@Zn||MnO2 batteries can display the highest capacity of up to 140 mAh g-1 without noticeable decay even after 1000 cycles. Moreover, a motor-driven fan and electronic wristwatch powered by wearable ZIBs can demonstrate the practical feasibility of LAO@Zn||MnO2 in wearable electronic equipment.

Stabilizing Zinc Hexacyanoferrate Cathode by Low Contents of Cs Cations for Aqueous Zn-Ion Batteries.

Exploring cathode materials with excellent electrochemical performance is crucial for developing rechargeable aqueous zinc ion batteries (RAZIBs). Zinc hexacyanoferrate (ZnHCF), a promising candidate of cathode materials for RAZIBs, suffers from severe electrochemical instability issues. This work reports using low contents of alkaline metal cations as electrolyte additives to improve the cycle performance of ZnHCF. The cations with large sizes, particularly Cs+, changes the intercalation chemistry of ZnHCF in RAZIBs. During cycling, Cs+ cations co-inserted into ZnHCF stabilize the host structure. Meanwhile, a stable phase of CsZn[Fe(CN)6] forms on the ZnHCF cathode, suppressing the loss of active materials through dissolution. ZnHCF gradually converts to an electrochemically inert Zn-rich phase during long-term cycling in aqueous electrolyte, leading to irreversible capacity loss. Introducing Cs+ in the electrolyte inhibits this conversion reaction, resulting in the extended lifespan. Owing to these advantages, the capacity retention rate of ZnHCF/Zn full batteries increases from the original 7.0 % to a high value of 54.6 % in the electrolyte containing 0.03 M of Cs2SO4 after 300 cycles at 0.25 A ⋅ g-1. This research provides an in-depth understanding of the electrochemical behavior of ZnHCF in aqueous zinc electrolyte, beneficial for further optimizing ZnHCF and other metal hexacyanoferrates.

Constructing a 3D Zinc Anode Exposing the Zn(002) Plane for Ultralong Life Zinc-Ion Batteries.

The limited lifespan of aqueous Zn-ion batteries (ZIBs) is primarily attributed to the irreversible issues associated with the Zn anode, including dendrite growth, hydrogen evolution, and side reactions. Herein, a 3D Zn anode exposing Zn(002) crystal planes (3D-Zn(002) anode) is first constructed by an electrostripping method in KNO3 solution. Experiments and theoretical calculations indicate that the priority adsorption of KNO3 on Zn(100) and Zn(101) planes decreases the dissolution energy of Zn atoms, thereby exposing more Zn(002) planes. The 3D-Zn(002) anode effectively regulates ion flux to realize the uniform nucleation of Zn2+. Moreover, it can inhibit water-induced formation of side-products and hydrogen evolution reaction. Consequently, the 3D-Zn(002) symmetrical cell exhibits an exceptionally long lifespan surpassing 6000 h at 5.0 mA cm-2 with a capacity of 1.0 mAh cm-2, and enduring 8500 cycles at 30 mA cm-2 with a capacity of 1.0 mAh cm-2. Besides, when NH4V4O10 is used as the cathode, the 3D-Zn(002)//NH4V4O10 full cell shows stable cycling performance with a capacity retention rate of 75.7% after 4000 cycles at 5.0 A g-1. This study proposes a feasible method employing a 3D-Zn(002) anode for enhancing the cycling durability of ZIBs.

Blocking Interfacial Proton Transport via Self-Assembled Monolayer for Hydrogen Evolution-Free Zinc Batteries.

Aqueous Zn-ion batteries (ZIBs) are promising next-generation energy storage devices, yet suffer from the issues of hydrogen evolution reaction (HER) and intricate side reactions on the Zn anode surface. The hydrogen (H)-bond networks play a critical role in interfacial proton transport that may closely relate to HER but are rarely investigated. Herein, we report a self-assembled monolayer (SAM) strategy which is constructed by anchoring ionic liquid cations on Ti3C2Tx substrate for HER-free Zn anode. Molecule dynamics simulations reveal that the rationally designed SAM with a high coordination number of water molecules (25-27, 4-6 for Zn2+) largely reduces the interfacial densities of H2O molecules, therefore breaking the connectivity of H-bond networks and blocking proton transport on the interface, by which the HER is suppressed. Then, a series of in situ characterizations demonstrate that negligible amounts of H2 gas are collected from the Zn@SAM-MXene anode. Consequently, the symmetric cell enables a long-cycling life of 3000 h at 1 mA cm-2 and 1000 h at 5 mA cm-2. More significantly, the stable Zn@SAM-MXene films are successfully used for coin full cells showing high-capacity retention of over 94 % after 1000 cycles and large-area (10×5 cm2) pouch cells with desired performance.

Massively Reconstructing Hydrogen Bonding Network and Coordination Structure Enabled by a Natural Multifunctional Co-Solvent for Practical Aqueous Zn-Ion Batteries.

The practical application of aqueous Zn-ion batteries (AZIBs) is hindered by the crazy Zn dendrites growth and the H2O-induced side reactions, which rapidly consume the Zn anode and H2O molecules, especially under the lean electrolyte and Zn anode. Herein, a natural disaccharide, d-trehalose (DT), is exploited as a novel multifunctional co-solvent to address the above issues. Molecular dynamics simulations and spectral characterizations demonstrate that DT with abundant polar -OH groups can form strong interactions with Zn2+ ions and H2O molecules, and thus massively reconstruct the coordination structure of Zn2+ ions and the hydrogen bonding network of the electrolyte. Especially, the strong H-bonds between DT and H2O molecules can not only effectively suppress the H2O activity but also prevent the rearrangement of H2O molecules at low temperature. Consequently, the AZIBs using DT30 electrolyte can show high cycling stability even under lean electrolyte (E/C ratio = 2.95 µL mAh-1), low N/P ratio (3.4), and low temperature (-12 °C). As a proof-of-concept, a Zn||LiFePO4 pack with LiFePO4 loading as high as 506.49 mg can be achieved. Therefore, DT as an eco-friendly multifunctional co-solvent provides a sustainable and effective strategy for the practical application of AZIBs.

Synchronous Regulation of D-Band Centers in Zn Substrates and Weakening Pauli Repulsion of Zn Ions Using the Ascorbic Acid Additive for Reversible Zinc Anodes.

The advanced aqueous zinc-ion batteries (AZIBs) are still challenging due to the harmful reactions including hydrogen evolution and corrosion. Here, a natural small molecule acid vitamin C (Vc) as an aqueous electrolyte additive has been selectively identified. The small molecule Vc can adjust the d band center of Zn substrate which fixes the active H+ so that the hydrogen evolution reaction (HER) is restrained. Simultaneously, it could also fine-tune the solvation structure of Zn ions due to the enhanced electrostatics and reduced Pauli repulsion verified by energy decomposition analysis (EDA). Hence, the cell retains an ultra-long cycle performance of over 1300 cycles and a superior Coulombic efficiency (CE) of 99.5 %. The prepared full cells display increased rate capability, cycle lifetime, and self-discharge suppression. Our results shed light on the mechanistic principle of electrolyte additives on the performance improvement of ZIBs, which is anticipated to render a new round of studies.