Stable Anode Research Articles

Nanofluid channels mitigated Zn2+ concentration polarization prolonged over 30 times lifespan for reversible zinc anodes

Despite interfacial engineering protects zinc anode from electrolyte corrosion, the suppressed kinetics process on the anode surface/interface circumscribes their cyclic stability, especially dendritic growth induced by ion concentration gradients. Here, the zinophilic nanofluid channels (ZNC) protective layer on zinc surface are designed for the rapid Zn2+ transport kinetic in the reversible cycling process. The ZNC demonstrates high separation pressure between ions and the channel surface due to the capillary effect, allowing Zn2+ to quickly migrate along the channel wall (Zn2+ transference numbers up to 0.72). Therefore, the unique channel modules alleviate concentration polarization from rapid Zn2+ consumption and maintain uniform deposition of Zn ions. Consequently, The ZNC protective layer anode exhibits significantly improved cycle life by more than 30 times (over 4000 h at 1 mA cm−2) that of bare Zn. The full battery exhibits stable cycling performance with excellent capacity retention (∼100%) after 5000 cycles. Our work provides innovative insights into the role of nanofluids in improving the stability of zinc anodes, offering enlightening perspectives for long-cycle life zinc-based batteries.

Regulating the Zn electrode/electrolyte interface with lactose additive for high performance Zn anode

The practical utilization of rechargeable aqueous zinc metal batteries (AZMBs) has been constrained by the formation of zinc dendrites and other associated issues. This article introduces lactose, a compound rich in hydroxyl groups, as an electrolyte additive into the aqueous solution of the electrolyte with the objective of suppressing the harmful growth of zinc dendrites. The lactose additive, with its strong zincophilicity, robust intermolecular hydrogen bonding, and a large number of exposed high electronegativity hydroxyl groups, enables lactose to effectively modulate the electrode/electrolyte interface in a dynamic manner, thereby achieving the stability and reversibility of the zinc anode. The findings presented in this work demonstrate the uniform deposition and stripping of zinc in a 2 M ZnSO4 electrolyte with the addition of lactose, thereby enhancing the cycling performance of Zn||Zn batteries. The alteration of the zinc ion environment on the surface of the zinc electrode, in conjunction with the dynamic modulation of the Gouy-Chapman-Stern (GCS) layer by lactose, increases the nucleation overpotential, thereby facilitating to a uniform deposition morphology in lieu of the formation of large-scale dendrites. Furthermore, the formation of hydrogen bonds serves to prevent the occurrence of side reactions. These factors act in concert to enhance the electrochemical performance of AZMBs. The addition of lactose to the electrolyte has resulted in a significant enhancement in the Coulombic efficiency of the card-type Zn||Cu asymmetric battery, reaching 99.7 %. The biodegradability of lactose and the sustainability of its source make this research conducive to the development of environmentally friendly battery electrolyte additives.

Growing mulberry-like copper on copper current collector for stable lithium metal battery anodes

Growing mulberry-like copper on copper current collector for stable lithium metal battery anodes

Toward waterproof magnesium metal anodes by uncovering water-induced passivation and drawing water-tolerant interphases.

Magnesium (Mg) metal is a promising anode candidate for high-energy and cost-effective multivalent metal batteries, but suffers from severe surface passivation in conventional electrolytes, especially aqueous solutions. Here, we uncover that MgH2, in addition to the well-known MgO and Mg(OH)2, can be formed during the passivation of Mg by water. The formation mechanism and spatial distribution of MgH2, and its detrimental effect on interfacial dynamics and stability of Mg anode are revealed by comprehensive experimental and theoretical investigations. Furthermore, a graphite-based hydrophobic and Mg2+-permeable water-tolerant interphase is drawn using a pencil on the surface of Mg anodes, allowing them to cycle stably in symmetric (> 900 h) and full cells (> 500 cycles) even after contact with water. The mechanistic understanding of MgH2-involved Mg passivation and the design of pencil-drawn waterproof Mg anodes may inspire the further development of Mg metal batteries with high water resistance.

Li+ Ion-Dipole Interaction-Enabled a Dynamic Supramolecular Elastomer Interface Layer for Dendrite-Free Lithium Metal Anodes.

The unstable lithium (Li)/electrolyte interface, causing inferior cycling efficiency and unrestrained dendrite growth, has severely hampered the practical deployment of Li metal batteries (LMBs), particularly in carbonate electrolytes. Herein, we present a robust approach capitalizing on a dynamic supramolecular elastomer (DSE) interface layer, which is capable of being reduced with Li metal to spontaneously form strong Li+ ion-dipole interaction, thereby enhancing interfacial stability in carbonate electrolytes. The soft phase in the DSE structure enables fast Li+ transport via loosely coordinated Li+-O interaction, while the hard phase, rich in electronegative lithiophilic sites, drives the generation of fast-ion-conducting solid electrolyte interface components, including Li3N and Li2S. Furthermore, the dynamically resilient DSE network composed of soft and hard phases protects Li anodes from electrolyte corrosion and accommodates volume changes during cycling. All features of the DSE layer synergistically facilitate uniform Li+ deposition and suppress Li dendrite propagation, ensuring a stable and dendrite-free Li anode. Consequently, the symmetric Li||Li cell incorporating the DSE layer achieves cycling stability exceeding 6000 h under 1 mA cm-2 and 1 mA h cm-2 conditions. Furthermore, full cell pairing DSE/Li anode with LiFePO4 (LFP) or high-voltage LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes exhibits high-efficiency Li deposition and cycling stability, even under constrained conditions of limited Li (40 μm) and ultrahigh loading NMC811 cathode (21.5 mg cm-2). This study underscores the effectiveness of the ion-dipole interaction-enabled DSE network in developing stable, high-energy-density LMBs.

Synthesis Methods of Si/C Composite Materials for Lithium-Ion Batteries

Silicon anodes present a high theoretical capacity of 4200 mAh/g, positioning them as strong contenders for improving the performance of lithium-ion batteries. Despite their potential, the practical application of Si anodes is constrained by their significant volumetric expansion (up to 400%) during lithiation/delithiation, which leads to mechanical degradation and loss of electrical contact. This issue contributes to poor cycling stability and hinders their commercial viability, and various silicon–carbon composite fabrication methods have been explored to mitigate these challenges. This review covers key techniques, including ball milling, spray drying, pyrolysis, chemical vapor deposition (CVD), and mechanofusion. Each method has unique benefits; ball milling and spray drying are effective for creating homogeneous composites, whereas pyrolysis and CVD offer high-quality coatings that enhance the mechanical stability of silicon anodes. Mechanofusion has been highlighted for its ability to integrate silicon with carbon materials, showing the potential for further optimization. In light of these advancements, future research should focus on refining these techniques to enhance the stability and performance of Si-based anodes. The optimization of the compounding process has the potential to enhance the performance of silicon anodes by addressing the significant volume change and low conductivity, while simultaneously addressing cost-related concerns.

Functional organic 7,7,8,8‐tetracyanoquinodimethane artificial layers for the dendrite suppressed lithium metal anodes

AbstractThe large‐scale industrialization of lithium metal (Li), as a potential anode for a high energy density energy storage system, has been hindered by dendrite growth. The construction of an artificial solid electrolyte interphase layer featuring high ionic and low electronic conductivity has been verified to be a high‐performance strategy to confine the dendrite growth and promote the Li anode stability. Therefore, a functional organic protective layer is homogeneously deposited on the Li anode surface via an in situ chemical reaction between tetracyanoquinodimethane (TCNQ) and Li. The as‐synthesized Lin‐TCNQ organic film could efficiently trap non‐uniform Li deposition and restrain dendrite propagation. Particularly, an asymmetric M‐TCNQ‐Li|Cu cell with the Lin‐TCNQ layer breezed through a high Coulombic efficiency of 91.15% after 100 cycles at 1.0 mA cm−2. The M‐TCNQ‐Li|NCM622 cell delivered a high capacity of 143.40 mAh g−1 at 0.2 C and maintained a good cyclic stability of 110.44 mAh g−1 after 160 cycles. The analysis results of spectroscopic tests further demonstrate that the Lin‐TCNQ with the enhanced absorption energy is conducive to lithiophilicity and decreases the overpotential of Li deposition.

Atomically Asymmetrical Ir-O-Co Sites Enable Efficient Chloride-mediated Ethylene Electrooxidation in Neutral Seawater.

The chloride-mediated ethylene oxidation reaction (EOR) of ethylene chlorohydrin (ECH) via electrocatalysis is practically attractive because of its sustainability and mild reaction conditions. However, the chlorine oxidation reaction (COR), which is essential for the above process, is commonly catalyzed by dimensionally stable anodes (DSAs) with high contents of precious Ru and/or Ir. The development of highly efficient COR electrocatalysts composed of nonprecious metals or decreased amounts of precious metals is highly desirable. Herein, we report a modified Co3O4 with a single-atom Ir substitution (Ir1/Co3O4) as a highly efficient COR electrocatalyst for chloride-mediated EOR to ECH in neutral seawater. Ir1/Co3O4 achieves a Faradaic efficiency (FE) of up to 94.8% for ECH generation and remarkable stability. Combining experimental results and density functional theory (DFT) calculations, the unique atomically asymmetrical Ir-O-Co configuration with a strong electron coupling effect in Ir1/Co3O4 can accelerate electron transfer to increase the reaction kinetics and maintain the structural stability of Co3O4 during COR. Moreover, a coupling reaction system integrating the anodic chloride-mediated and cathodic H2O2-mediated EOR show a total FE of ~170% for paired electrosynthesis of ECH and ethylene glycol (EG) using ethylene as the raw material. The technoeconomic analysis highlights the promising application prospects of this system.

Atomically Asymmetrical Ir–O–Co Sites Enable Efficient Chloride‐mediated Ethylene Electrooxidation in Neutral Seawater

The chloride‐mediated ethylene oxidation reaction (EOR) of ethylene chlorohydrin (ECH) via electrocatalysis is practically attractive because of its sustainability and mild reaction conditions. However, the chlorine oxidation reaction (COR), which is essential for the above process, is commonly catalyzed by dimensionally stable anodes (DSAs) with high contents of precious Ru and/or Ir. The development of highly efficient COR electrocatalysts composed of nonprecious metals or decreased amounts of precious metals is highly desirable. Herein, we report a modified Co3O4 with a single‐atom Ir substitution (Ir1/Co3O4) as a highly efficient COR electrocatalyst for chloride‐mediated EOR to ECH in neutral seawater. Ir1/Co3O4 achieves a Faradaic efficiency (FE) of up to 94.8% for ECH generation and remarkable stability. Combining experimental results and density functional theory (DFT) calculations, the unique atomically asymmetrical Ir‐O‐Co configuration with a strong electron coupling effect in Ir1/Co3O4 can accelerate electron transfer to increase the reaction kinetics and maintain the structural stability of Co3O4 during COR. Moreover, a coupling reaction system integrating the anodic chloride‐mediated and cathodic H2O2‐mediated EOR show a total FE of ~170% for paired electrosynthesis of ECH and ethylene glycol (EG) using ethylene as the raw material. The technoeconomic analysis highlights the promising application prospects of this system.

Dual zinco-phobic/-philic ferroelectric nanorods coated mesh for stable Zn anode

Aqueous Zn-ion batteries are emerging as a promising option for energy storage systems due to their safety and environmental benefits. However, their stability and reversibility are often hindered by dendrite growth and interfacial side reactions. In this study, we introduce an innovative strategy to address these issues by engineering an artificial interfacial layer (AIL) on Zn anode surface. This AIL is composed of a dual zinco-phobic/-philic ferroelectric nanorods (FE NRs) mesh, which contrasts with the traditional BaTiO3 nanoparticles. The BTO NRs, particularly those with exposed P4/mmm (100) and (211) facets enriched with oxygen vacancy, facilitate a partial phase transition from the FE tetragonal P4mm phase to the paraelectric tetragonal P4/mmm phase, thereby creating dual zinco-phobic/-philic sites. Additionally, the integration of microchannels within the FE BTO NRs mesh can efficiently modulate the electric field distribution and Zn2+ concentration, leading to a more uniform Zn deposition, as conformed by electrochemical simulations. The Zn anode coated with the FE BTO NRs mesh exhibits impressive performance, achieving an ultralong cycle life of 3050 h at 1 mA cm−2 and 1mAh cm−2. It sustains a Coulombic efficiency exceeding 99.8 % over 2000 cycles, highlighting its exceptional reversibility. These findings underscore the potential of the dual zinco-phobic/-philic FE NRs mesh in overcoming the challenges faced in aqueous metal-ion batteries, showcasing its versatility and the significant performance enhancements it can offer.

A review of recent developments in the design of electrolytes and solid electrolyte interphase for lithium metal batteries

AbstractLithium metal batteries offer a promising solution for high density energy storage due to their high theoretical capacity and negative electrochemical potential. However, implementing of these batteries faces challenges related to electrolyte instability and the formation of a solid electrolyte interphase (SEI) on the lithium (Li) metal anode. The decomposition of liquid electrolytes leading to the creation of the SEI emphasizes the significance of the type of Li salt, solvent, and additives designed and used, as well as their interactions during the formation of the SEI. For practical applications, ensuring both the reversibility of the Li metal anode and electrolyte stability at high voltages is crucial. In this review, we explore recent advancements in addressing these challenges through new designs of electrolytes and SEI engineering practices. Specifically, we investigate the effects of electrolyte systems, including carbonate‐based and ether‐based solutions, along with modifications to these electrolyte systems aimed at achieving a more stable interface with the Li metal anode. Additionally, we discuss various artificial SEI structures based on organic and inorganic components. By critically examining recent research in these areas, this review provides valuable insights into current state‐of‐the‐art strategies for enhancing the performance and safety of Li metal batteries.image

Covalent Carbide Interconnects Enable Robust Interfaces and Thin SEI for Graphite Anode Stability under Extreme Fast Charging.

Carbonaceous and carbon-coated electrodes are ubiquitous in electrochemical energy storage and conversion technologies due to their electrochemical stability, lightweight nature, and relatively low cost. However, traditional reliance on conductive additives and binders leads to impermanent electrical pathways. Here, a general approach is presented to fabricate robust electrodes with a progressive failure mechanism by introducing carbide-based interconnects grown via carbothermal conversion of (5 wt%) titanium hydride nanoparticles. This method concurrently enhances both electrical and mechanical properties within the electrode architecture. The resulting chemical bonding between active materials establishes a novel mechanism to maintain stable electrical pathways during cycling. Employed as Li-ion battery anodes, these electrodes exhibit improved cyclability, achieving 80% capacity retention after 800 fast-charge cycles at moderate loading (1 mAh cm- 2). High loading cells with areal capacity of 3 mAh cm-2 show significantly improved cycle lifeover the same number of cycles. This performance improvement is attributed to the absence of significant impedance growth and a thinner solid electrolyte interphase (SEI) layer formed at high current densities (4C) as demonstrated by X-ray photoelectron spectroscopy and transmission electron microscopy studies. The enhanced conductivity facilitates SEI formation, lowering ionic impedance and mitigating lithium plating, ultimately leading to the reported extended cycle life.

Trace Amounts of Multifunctional Electrolyte Additives Enhance Cyclic Stability of High-Rate Aqueous Zinc-Ion Batteries.

Aqueous zinc ion batteries (AZIBs) are renowned for their exceptional safety and eco-friendliness. However, they face cycling stability and reversibility challenges, particularly under high-rate conditions due to corrosion and harmful side reactions. This work introduces fumaric acid (FA) as a trace amount, suitable high-rate, multifunctional, low-cost, and environmentally friendly electrolyte additive to address these issues. FA additives serve as prioritized anchors to form water-poor Inner Helmholtz Plane on Zn anodes and adsorb chemically on Zn anode surfaces to establish a unique in situ solid-electrolyte interface. The combined mechanisms effectively inhibit dendrite growth and suppress interfacial side reactions, resulting in excellent stability of Zn anodes. Consequently, with just tiny quantities of FA, Zn anodes achieve a high Coulombic efficiency (CE) of 99.55 % and exhibit a remarkable lifespan over 2580 hours at 5mA cm-2, 1 mAh cm-2 in Zn//Zn cells. Even under high-rate conditions (10mA cm-2, 1 mAh cm-2), it can still run almost for 2020 hours. Additionally, the Zn//V2O5 full cell with FA retains a high specific capacity of 106.95 mAh g-1 after 2000 cycles at 5 A g-1. This work provides a novel additive for the design of electrolytes for high-rate AZIBs.

Organic Electrolyte Additives for Aqueous Zinc Ion Batteries:Progress and Outlook.

Aqueous zinc ion batteries (AZIBs) are considered one of the most prospective new-generation electrochemical energy storage devices with the advantages of high specific capacity, good safety, and high economic efficiency. Nevertheless, the enduring problems of low Coulombic efficiency (CE) and inadequate cycling stability of zinc anodes, originating from dendrites, hydrogen precipitation and passivation, are closely tied to their thermodynamic instability in aqueous electrolytes, which significantly shortens the cycle life of the battery. Electrolyte additives can solve the above difficulties and are important for the advancement of affordable and reliable AZIBs. Organic electrolyte additives have attracted widespread attention due to their unique properties, however, there is a lack of systematic discussion on the performance and mechanism of action of organic electrolyte additives. In this review, a comprehensive overview of the application of organic electrolyte additives in AZIBs is presented. The role of organic electrolyte additives in stabilizing zinc anodes is described and evaluated. Finally, further potential directions and prospects for improving and directing organic electrolyte additives for AZIBs are presented.

Harnessing biological insights: Integrating proton regulation, pH buffer and zincophility for highly stable Zn anode

Zinc anodes are severely threatened by hydrogen evolution, dendrite growth and by-products. Inspired by the mechanisms of L-carnosine (L-car) in maintaining intracellular pH stability and fostering mucosal repair in biological systems, this study innovatively proposed a comprehensive strategy integrating proton regulation, pH buffer and zincophility by introducing L-car as an electrolyte additive to achieve remarkable stability of zinc anode. Experimental validations and theoretical calculations demonstrate that the abundant N and O sites in L-car can form robust hydrogen bonds with protons, effectively impeding interfacial proton transport and substantially mitigating HER. Moreover, dual pH buffering sites of L-car facilitate dynamic modulation of proton concentration, stabilizing the pH of electrolyte, and suppressing Zn corrosion/passivation/by-product. Concurrently, the robust chelation between L-car and Zn2+ orchestrates uniform zinc ion deposition. This synergistic trifecta of L-car endows Zn ion batteries with an extraordinary cycling stability, extending to an ultralong duration of 5500 h. Furthermore, the Zn//MnO2 full battery, demonstrates remarkable stability, retaining a specific capacity of 106.1 mAh/g with 79.2 % retention after 1000 cycles at 3 A/g. This study pioneers the interdisciplinary application of L-car in electrolyte modification, presenting a novel paradigm for stabilizing zinc anodes.

Achieving Highly Stable Zn Anode via Regulating the Solvation Sheath Structure of Electrolyte with a Maltodextrin Additive

Achieving Highly Stable Zn Anode via Regulating the Solvation Sheath Structure of Electrolyte with a Maltodextrin Additive

Weak solvation effects and molecular-rich layers induced water-poor Helmholtz layers boost highly stable Zn anode

The advancement of aqueous Zn-based energy storage systems encounters major challenges due to the occurrence of side reactions and the growth of dendrites caused by the highly active nature of water in the aqueous electrolyte. Herein, a zwitterion additive named sulfonated amphoteric betaine (referred to as DMAPS) regulates the Zn2+ electrolyte environment through a weak solvation effect to promote highly stable Zn anodes. The inherently occurring anionic (-SO3-) and cationic (-NR4+) counterions in the DMAPS chain can be effectively separated under an external electric field to enable the creation of distinct ion migration pathways, thereby significantly enhancing the transportation of electrolyte ions. Moreover, DMAPS can be adsorbed onto the surface of Zn anode to form a H2O-poor Helmholtz layer, which can serve as a protective barrier to suppress corrosion of the Zn anode by free H2O and inhibits the formation of differential electric field to facilitate the directional deposition of Zn2+. In addition, density functional theory (DFT) and molecular dynamics (MD) further assisted in demonstrating the intrinsic mechanism of the reconstruction of the solvated sheath structure of Zn2+ by DMAPS. As a result, the Zn//Zn symmetric cell in ZnSO4+DMAPS solution can be cycled steadily for 2100 h at a current density of 1 mA cm-2 and 1 mAh cm-2. The assembled Zn ion hybrid capacitor with ZnSO4+DMAPS electrolyte was stably cycled for 20,000 cycles with 90% capacity retention at 5 A g-1.

MgF2 Interface Engineering Promotes the Growth and Stability of LiF-Rich Solid-Electrolyte Interphases on Si-C.

Volume expansion of the Si-C anode during the charging/discharging process causes continuous fracture/formation of the solid electrolyte interface (SEI), which leads to rapid capacity fading. Here, we designed a MgF2-modified separator (MF-PP) to construct a fluorine-rich SEI layer by generating more LiF. The robust SEI layer formed can alleviate the volume stress and prevent crack growth in Si-C electrodes. After 450 cycles, the Si-C||MF-PP half cell retained a reversible capacity of 543.2 mAh g-1, while the LFP||MF-PP||Si-C full cell maintained a reversible capacity of 103.4 mAh g-1 with high Coulombic efficiency after 100 cycles. This facile and low-cost separator modification strategy provides an easily scalable approach to develop stable Si-based anodes for next-generation high-energy-density systems.

Comprehensive Understanding of Steric‐Hindrance Effect on the Trade‐Off Between Zinc Ions Transfer and Reduction Kinetics to Enable Highly Reversible and Stable Zn Anodes

AbstractThe electrode interface concentration polarization attributed to the contradiction between sluggish mass transfer process and rapid electrochemical reduction kinetics significantly restricts the practical application of Zn anode. Creating a moderate Zn ions transfer and reduction chemistry is essential for durable zinc‐ion batteries. In this work, this trade‐off effect is realized by selecting large‐size 4‐Aminomethyl cyclohexanecarboxylic acid (AMCA) molecule as the electrolyte additive. Intriguingly, AMCA molecules reorganize the Zn2+ solvation structure via the robust coordination with Zn2+ and reconstruct H‐bond networks, giving a pulled desolvation process. Meanwhile, AMCA enlarges the Zn2+ solvation size with a push force, confining the rapid electrochemical reduction kinetics. The balanced chemical environment is maintained via the moderate pull‐push interplay. Besides, AMCA can anchor on zinc surface to create a water‐poor microenvironment, fostering homogeneous Zn (002) deposition and effectively restricting water‐induced side‐reactions. Notably, the Zn||Zn symmetric cell with AMCA operates stably over 167 days at 20 mA cm−2. Moreover, the Zn||VOX full cell employed AMCA ensures outstanding capacity retention of 99.15% after 590 cycles at 2 A g−1, even with low N/P (4.3), lean electrolyte (50 µL mAh−1) and ultrathin Zn foil of 10 µm. This work reveals unique insights into the balanced interfacial chemistry design toward high‐performance zinc batteries.

Synchronous Modulation of H-bond Interaction and Steric Hindrance via Bio-molecular Additive Screening in Zn Batteries.

In addressing challenges such as side reaction and dendrite formation, electrolyte modification with bio-molecule sugar species has emerged as a promising avenue for Zn anode stabilization. Nevertheless, considering the structural variability of sugar, a comprehensive screening strategy is meaningful yet remains elusive. Herein, we report the usage of sugar additives as a representative of bio-molecules to develop a screening descriptor based on the modulation of the hydrogen bond component and electron transfer kinetics. It is found that xylo-oligosaccharide (Xos) with the highest H-bond acceptor ratio enables efficient water binding, affording stable Zn/electrolyte interphase to alleviate hydrogen evolution. Meanwhile, sluggish reduction originated from the steric hindrance of Xos contributes to optimized Zn deposition. With such a selected additive in hand, the Zn||ZnVO full cells demonstrate durable operation. This study is anticipated to provide a rational guidance in sugar additive selection for aqueous Zn batteries.