Dendritic Growth Mechanism Research Articles

The Mechanism of Aluminum Deposition and Dendrite Growth on a Copper Substrate in Anode-Free Aluminum Batteries.

Given the critical demand for batteries with a high energy density and the global scarcity of lithium, anode-free aluminum batteries (AFABs) have attracted significant attention. AFABs utilize collectors instead of traditional anode metal foils, eliminating the need for anode materials and significantly enhancing the energy density of the batteries. However, the proliferation of aluminum dendrites might cause safety risks and reduce Coulombic efficiency, possibly impeding commercialization. This study employs molecular dynamics (MD) simulations to explore the deposition mechanisms of aluminum (Al) on copper (Cu) collectors and the dynamics of aluminum dendrite growth under nonhomogeneous deposition conditions. The results indicate that the surface properties of the Cu substrate significantly affect aluminum deposition, leading to more homogeneous and amorphous deposition on Cu(110) surfaces. However, the FCC structure of Al atoms on the Cu(111) surfaces exhibited the largest number. Strategically increasing the temperature and pressure can effectively prevent the formation of aluminum dendrites. The results are helpful for enhancing the battery cycle stability and the application of novel AFABs.

Designing sodium alloys for dendrite‐free sodium‐metal batteries

AbstractSodium metal, with a high theoretical specific capacity (∼1165 mA h g−1) and a low redox potential (−2.71 V vs. SHE) as well as low cost, becomes an attractive option for high‐energy‐density sodium secondary batteries. However, the practical application of sodium metal anodes is hindered by dendrite growth, which results in low energy efficiency, poor lifetime and serious safety issues. To address this challenge, researchers propose various strategies, including the formation of sodium alloys (Na‐M alloys, M = Sn, Sb, Bi, In, etc.) through alloying reaction. The alloying effect has a positive impact in terms of reducing the local current density, mitigating the volume expansion, and inhibiting the dendrite growth. It is thus an effective solution for constructing high‐performance sodium secondary batteries. This review systematically describes the mechanism of dendrite growth and the alloying process of Na‐M alloys, summarizes recent research progress and strategies for applying Na‐M alloys to create dendrite‐free sodium secondary batteries, as well as presents prospects for the development of Na‐M alloys and offers clear suggestions for future research. This review aims to inspire further efforts to build dendrite‐free, high‐performance sodium secondary batteries and broaden a new aspect for the next‐generation battery systems.

Study on the dendritic growth and grain boundary formation in the suddenly expanded cross-section of single crystal superalloy during directional solidification process

The dendritic growth behavior at the suddenly expanded cross-section of single crystal blades dramatically affects the defects formation. In this work, the dendrite growth mechanism is deeply investigated in the rectangular platform by analyzing the quasi-three-dimensional microstructures via the continuous image shooting and orientation scanning, combined with simulating the thermal fields at different furnace temperatures. As the solidification proceeds to the platform, the secondary branches at the connection between the primary zone and the expansion zone grow outwardly. Some secondary branches growth direction deflects the preferred orientation. The well-developed tertiary arms would develop on some secondary branches. The different generation dendrites with the different growth directions converge and form the boundary angles. The tertiary proportion and the dendrite boundary lengthes/angles show the decrease tendency as the temperature increases. The undercooling in the platform edges and corners from the concave/convex degree of isothermal surface should be responsible for the formation and convergence of the different generation dendrites the matrix dendrite expanding behavior towards the platform edge and their subsequent upward directional growth. The nonuniformity of thermal gradient at the isothermal surface should affects the inconsistency of the growth directions of the different dendrites, which provides the more opportunity for the dendrite deviation. This study sheds light on the dendrite growth behavior when the single crystal blade directionally solidifies through the suddenly expanded platform.

Phase-Field Study of the Competitive Growth Mechanism of Dendrites in the Directed Energy Deposition Melt Pool of RCF103 Alloy

Phase-Field Study of the Competitive Growth Mechanism of Dendrites in the Directed Energy Deposition Melt Pool of RCF103 Alloy

Review of the Real-Time Monitoring Technologies for Lithium Dendrites in Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) have the advantage of high energy density, which has attracted the wide attention of researchers. Nevertheless, the growth of lithium dendrites on the anode surface causes short life and poor safety, which limits their application. Therefore, it is necessary to deeply understand the growth mechanism of lithium dendrites. Here, the growth mechanism of lithium dendrites is briefly summarized, and the real-time monitoring technologies of lithium dendrite growth in recent years are reviewed. The real-time monitoring technologies summarized here include in situ X-ray, in situ Raman, in situ resonance, in situ microscopy, in situ neutrons, and sensors, and their representative studies are summarized. This paper is expected to provide some guidance for the research of lithium dendrites, so as to promote the development of LIBs.

Toward Quantitative Electrodeposition via In Situ Liquid Phase Transmission Electron Microscopy: Studying Electroplated Zinc Using Basic Image Processing and 4D STEM.

High energy density electrochemical systems such as metal batteries suffer from uncontrollable dendrite growth on cycling, which can severely compromise battery safety and longevity. This originates from the thermodynamic preference of metal nucleation on electrode surfaces, where obtaining the crucial information on metal deposits in terms of crystal orientation, plated volume, and growth rate is very challenging. In situ liquid phase transmission electron microscopy (LPTEM) is a promising technique to visualize and understand electrodeposition processes, however a detailed quantification of which presents significant difficulties. Here by performing Zn electroplating and analyzing the data via basic image processing, this work not only sheds new light on the dendrite growth mechanism but also demonstrates a workflow showcasing how dendritic deposition can be visualized with volumetric and growth rate information. These results along with additionally corroborated 4D STEM analysis take steps to access information on the crystallographic orientation of the grown Zn nucleates and toward live quantification of in situ electrodeposition processes.

Effect of WC particle size on the microstructure and tribological properties of high-speed laser cladding Ni/WC composite coatings

Ni/WC composite coatings with WC particle sizes of 30–65, 65–100, and 100–145 μm were prepared on 304 steel using high-speed laser-cladding (HSLC). The phase composition, microstructure, and wear mechanism of the composite coatings were studied. The dendrite-growth mechanism around WC with different particle sizes and the effects of WC with different particle sizes on the microhardness and tribological properties of the composite coatings were analyzed. The results demonstrated that the composite coating consisted of intermetallic compound Ni3Fe and secondary carbides W2C and (Cr, Fe)7C3. The composite coating exhibited good macroscopic morphology and uniform microstructure. The WC particle size obviously influenced the columnar and cellular dendrites in the coating. The microhardness values of the three groups of composite coatings were 419.35, 314.64, and 331.65 HV. The average friction coefficients were 0.4876, 0.5693, and 0.5439. The wear volumes were 0.001, 0.0015, and 0.002 mm3. The wear mechanisms included adhesive, abrasive, and oxidation wear mechanisms. The results verified that the WC coating with a small particle size possessed the best microhardness and tribological properties.

Recent advances in separator design for lithium metal batteries without dendrite formation: Implications for electric vehicles

Electric vehicle (EV) technology addresses the challenge of reducing carbon and greenhouse gas emissions. The power battery, which serves as the energy source for EVs, directly impacts their driving range, maximum speed, and service life. Considering the high energy density requirements for future EVs, lithium metal anodes possess several advantages such as high theoretical capacity, high energy and power density, and low electrochemical reduction potential which enable them to be a promising material for next-generation batteries. However, lithium metal anodes suffer from short cycle life and safety concerns due to the formation of dendritic and moss-like metal deposits that impede battery performance and reliability. This review will feature the recent advancement of functional separators to tackle these challenges. Firstly, this review presents a comprehensive review of the growth mechanism of lithium dendrites and delineates the underlying processes leading to battery failure. This aims to deepen understanding, which serves as a fundamental basis for classifying separators. Then, according to the growth of lithium dendrites and the failure process of lithium metal batteries, namely lithium-ion nucleation, growth of lithium dendrites, penetration of lithium dendrites into the separator, thermal runaway and even failure of the battery, four types of functional separators for different stages are proposed. The functions of these types of separators are to prevent the nucleation of lithium ions and regulate the uniform deposition of lithium ions, detect and eliminate dendrites, increase the mechanical strength of the separator and enhance the thermal stability and flame-retardancy of the separators, respectively. Finally, the recent advances of the above strategies are reviewed and discussed, existing critical problems are identified, and the future perspective of functional separators for the safety of lithium metal batteries is also discussed.

Mechanism of lithium dendrite growth on iron surfaces toward high-performance and safe anode-free lithium metal batteries

Selecting the Fe(111) surface, reducing surface cracks, and controlling the surface nanogroove structures can effectively prevent the formation of irreversible Li dendrites on the Fe collector, resulting in better performance of anode-free LMBs.

Mechanism and solutions of lithium dendrite growth in lithium metal batteries

Inhibiting lithium dendrite is a big challenge for developing lithium metal batteries. The work reviews possible mechanisms of lithium dendrite growth, discuses effective strategies for inhibiting lithium dendrites and proposes future direction.

Dendrite growth and inhibition in all-solid-state lithium metal batteries: in situ optical observation

Combining in situ optical microscopy, we are able to monitor the real-time evolution of dendrite pathways in pressurized all-solid-state cells and understand the dendrite growth mechanism in working solid-state cells.

Investigating the Mechanisms of Li Dendrite Formation in Sulfide Solid Electrolytes for All-Solid-State Batteries

As the primary use of Li-ion batteries shifts from small electronic devices to electric vehicles, there is a need to increase the stability and energy density of Li-ion batteries. In order to achieve high energy density, use of lithium metal as an anode has being considered due to its high theoretical capacity (3860 mAh g-1) and low reduction potential (-3.04 V vs. SHE). However, the liquid electrolyte used in Li-ion batteries is not only dangerous due to the risk of fire in case of leakage, but also has the disadvantage of shortening the lifetime of the battery due to the generation of lithium dendrites during cycling when lithium metal is used as anode. To overcome these disadvantages, all-solid-state batteries using solid electrolytes have emerged, which are expected to improve safety and cycling stability even when using lithium metal anodes. Among the various types of solid electrolytes, sulfide solid electrolytes are widely used due to their high ionic conductivity and ductility, which allows easy formation of good interfaces, resulting in high performance all-solid-state batteries.To date, many attempts have been made to use lithium metal anodes with solid electrolytes, but dendrite growth has not been completely suppressed.1 Dendrite growth is affected by many interface-related factors, such as void ratio, grain size, elastic modulus, reductive decomposition products, and electrical conductivity of the electrolyte, which must be clarified before the use of lithium metal anodes can be realized.2 It is essential to observe and analyse the changes during electrochemical tests in order to reveal the formation of Li dendrites under the conditions in which actual real cells operate. We have attempted to elucidate the dynamic structural changes at the interface using multimodal/multiscale operando X-ray CT under an applied pressure, as well as the reactions taking place at the interface by observing the interface products using X-ray absorption spectroscopy. In this study, X-ray diffraction, X-ray absorption spectroscopy, time-resolved impedance measurements and multi scale operando X-ray CT are used to determine the electrochemical and chemical mechanisms of Li dendrite formation in different sulfide solid electrolytes. By investigating and comparing the particle size, porosity, doping effect of halides and reduction resistance of solid electrolytes used in lithium metal solid-state batteries, the mechanism of Li dendrite growth and how each factor affects dendrite growth are investigated.Here, we discuss Li3PS4, halogen-doped Li3PS4, and argyrodite-based Li6PS5Cl as typical sulfide-based solid electrolytes; Li3PS4 is known to have a low elastic modulus, and a simple cold press could be used to reduce the inter-particle voids. However, Li3PS4 has a very narrow potential difference, which resulted in unwanted oxidation and reduction byproducts during battery cycling. The high electronic conductivity of the reduction products at the interface also led to the formation of electronic pathways, resulting in the concentration of current in several locations and ultimately triggering the formation of Li dendrites. On the other hand, in argyrodite Li6PS5Cl, the formation of an interfacial phase with low electronic conductivity, which is mainly composed of lithium chloride at the interface, suppresses the reduction reaction and thus the formation of Li dendrites. In the presentation, the relationship between the lithium dendrite formation and the operating conditions such as temperature and pressure will also be presented.

Functional Oriented Design of Composite Artificial Interface Layers Towards Stable Zinc Anodes In Aqueous Zinc‐ion Batteries

AbstractRechargeable aqueous zinc‐ion batteries (AZIBs) with metallic Zn anodes have been regarded as attractive candidates for large‐scale energy storage systems due to their affordability, safety, and high energy density. However, the practical implementation of rechargeable AZIBs is still hampered severely by the poor electrochemical stability and reversibility of Zn anodes, stemming from uncontrolled dendrite growth and rampant side reactions. Due to the versatility of different components in the composite artificial interface layer (AIL), great efforts on multifunctional AILs have recently been devoted to Zn anode protection for designing durable and stable AZIBs. This review first presents a comprehensive and timely summarization on the origin and mechanism of dendrite growth and side reactions, followed by the systematic summarization of five protection mechanisms/functions of the AILs. Next, recent advances are discussed in the manner of a correlation between the combined materials/structures in composite AILs and their synergetic functionality, highlighting the critical role of functional orientation design of the composite AILs towards stable Zn anodes. Finally, perspectives and suggestions are provided for designing highly effective multifunctional composite AILs towards Zn anodes for AZIBs.

Numerical simulation of factors in charge of dendrite growth in zinc-nickel single flow batteries

There is a potential danger of battery internal short-circuiting and shortened life span in zinc-nickel single flow batteries which is usually caused by the formation of dendritic crystals as a result of non-uniform electrodeposition. For the purpose of restraining dendrite growth and prolonging the battery service life, it is necessary to investigate the mechanism of dendrite growth that occurs on the surface of zinc anode. Here, a model for two-dimensional zinc dendrite growth is established by the phase field-lattice Boltzmann method (PF-LBM) to simulate how the morphology of zinc dendrites evolves as well as the corresponding distribution of the concentration field, potential field and flow field, and to analyze the influences of the applied voltage, electrolyte flow rate, anisotropy strength and exchange current density on dendrite growth. As the results show, higher exchange current density and applied voltage can promote dendrite growth. By choosing a suitable anisotropic strength, it is possible to change the morphology of the dendrites and decrease the formation of dendrites. Enlarging the electrolyte flow rate may make the distribution of ion concentration more uniform, which can inhibit the dendrite growth as well as affect the morphology of dendrites.

Unraveling the Mechanism of Very Initial Dendritic Growth Under Lithium Ion Transport Control in Lithium Metal Anodes.

Lithium metal deposition is strongly affected by the intrinsic properties of the solid-electrolyte interphase (SEI) and working electrolyte, but a relevant understanding is far from complete. Here, by employing multiple electrochemical techniques and the design of SEI and electrolyte, we elucidate the electrochemistry of Li deposition under mass transport control. It is discovered that SEIs with a lower Li ion transference number and/or conductivity induce a distinctive current transition even under moderate potentiostatic polarization, which is associated with the control regime transition of Li ion transport from the SEI to the electrolyte. Furthermore, our findings help reveal the creation of a space-charge layer at the electrode/SEI interface due to the involvement of the diffusion process of Li ions through the SEI, which promotes the formation of dendrite embryos that develop and eventually trigger SEI breakage and the control regime transition of Li ion transport. Our insight into the very initial dendritic growth mechanism offers a bridge toward design and control for superior SEIs.

The role of stress release in shaping iron whisker morphology during oxygen removal process

Metal growth in materials manufacturing or applications can significantly impact the efficiency and performance of processes. Despite extensive research efforts to understand dendrite and whisker growth mechanisms in various processes like battery charging and metal powder production, the growth of metal during the removal of oxygen from its oxides remains poorly understood. In this study, we investigated the role of stress release in the formation of iron whiskers. Our findings emphasized the significance of the oxygen removal process from hematite (Fe2O3) to wüstite (FeO), as a crucial step in initiating the structure for subsequent iron growth. We observed that, compared to carbon monoxide (CO), hydrogen (H2) exhibited superior stress release capabilities, leading to rapid volume shrinkage in the Fe2O3 to FeO stage. This preferential stress reduction by H2 was attributed to the development of a larger-sized nanoscale hole structure on the surface of iron oxides, effectively inhibiting the growth of filament-shaped whiskers.

Manufacturing High-Energy-Density Sulfidic Solid-State Batteries

All-solid-state batteries (ASSBs) using sulfide solid electrolytes with high room-temperature ionic conductivity are expected as promising next-generation batteries, which might solve the safety issues and enable the utilization of lithium metal as the anode to further increase the energy density of cells. Most researchers in the academic community currently focus on developing novel sulfide solid electrolytes, clarifying the interface issues between sulfide electrolytes and solid electrodes and mechanism of lithium dendrite growth in ASSB. However, there is a lacking in the technical route analysis about the commercialization of ASSBs based on sulfide solid electrolytes. This review mainly introduces the specific preparation methods of various parts in sulfide-based ASSBs, including the preparation methods of sulfide solid electrolyte particles, sulfide-based composite electrolyte membranes, composite cathodes and anodes, and analyzes the advantages and disadvantages of these methods. In addition, several schemes of ASSB assembly are also introduced. Finally, a perspective of large-scale production of sulfide-based ASSBs is provided, which is expected to accelerate the commercialization of sulfide-based ASSBs.

Mechanistic Exploration of Dendrite Growth and Inhibition for Lithium Metal Batteries

Li metal has been considered an ideal anode in lithium batteries due to its high theoretical capacity of 3860 mAh·g−1 and lowest negative reduction potential of −3.040 V among the standard hydrogen electrodes. However, lithium dendrites can easily grow on the surface of the negative electrode during charging, which results in a short circuit of the battery and reduces its efficiency. This paper investigated dendrite growth and inhibition mechanisms in lithium metal batteries to improve battery life. The impacts of the initial nucleation spacing, surface energy anisotropy strength, and interfacial electrochemical driving force on lithium dendrite growth were analyzed with electrochemical experiments and mathematical models. The results showed that the smaller nucleation spacing inhibits the growth of dendrite side branches and reduces the roughness of lithium metal deposition on the negative electrode. A lower interfacial energy anisotropy strength can slow down the growth of dendrite tips and improve the dendrite growth structure. The growth of the dendrites is influenced by the interfacial electrochemical driving force. Reducing the nucleation overpotential can effectively inhibit the growth of lithium dendrites.

Surface Control Behavior toward Crystal Regulation and Anticorrosion Capacity for Zinc Metal Anodes

The commercial application of high-safety aqueous zinc (Zn) secondary batteries is hindered by the poor cycling life of Zn metal anodes. Here we propose a dendrite growth and hydrogen evolution corrosion reaction mechanism from the binding energy of the deposited crystal plane on the Zn surface and the adsorption energy of H2O molecules on different crystal planes as well as the binding energy of H2O molecules with Zn2+ ions. The biomass-based alkyl polyglucoside (APG) surfactant is adopted as an electrolyte additive of 0.15% to regulate the preferential growth of a parallel Zn(002) plane and enhance the anticorrosion ability of Zn metal anodes. The robust binding and adsorption energies of APG with Zn2+ ions in the aqueous electrolyte and the Zn(002) plane on Zn surface generate a synergistic effect to increase the concentration of Zn2+ ions on the APG-adsorbed Zn(002) plane, endowing the continuous growth of the preferential parallel Zn(002) plane and the excellent anticorrosion capacity. Accordingly, the long-term cycle stability of 4000 h can be achieved for Zn anodes with APG additives, which is better than that with pure ZnSO4 electrolyte. With the addition of APG in the anolyte electrolyte, Zn-I2 full cells display excellent cycling performance (70 mAh g-1 after 20000 cycles) as compared with that without APG additives.

Insights into dendrite growth and phase transition during Cs2LiLaBr6 crystal growth

The lanthanum crystal Cs2LiLaBr6 (CLLB) has excellent scintillation properties for gamma/neutron discrimination. The initial melt with hyper-peritectic ratios (55 < LiBr/mol.% < 61) was found beneficial for CLLB crystal growth. The hyper-peritectic melt would pass though the peritectic point. However, the detailed process was still unknown. Herein, the dendrite growth and peritectic reaction were discovered near the peritectic point in CLLB single crystal ingots for the first time. The mechanism of dendrite growth was analyzed. The Cs2LaBr5-LiBr phase diagram was modified according to these results. The understanding of phase transition and dendrite evolution can guide crystal growth of CLLB and other similar elpasolite crystals.