Lithium Deposition Research Articles

Simulating Lithium Deposition on Planar Anode: The Role of Particle Reservoir and the Influence of Dendrite Growth on Current Density Profiles

Simulating Lithium Deposition on Planar Anode: The Role of Particle Reservoir and the Influence of Dendrite Growth on Current Density Profiles

Layer-by-Layer Assembly of Graphene Oxide and Silver Nanowire Thin Films with Interdigitated Nanostructure in Dendrite Suppressions of Li-Metal Batteries.

Reducing the thickness of the Li-metal anode is key to enhancing the energy density of batteries. However, poor initial lithium deposition on Cu current collectors can exacerbate the growth of lithium dendrites and limit performance. This study explores innovative strategies by fabricating graphene oxide (GO) and silver nanowire (AgNW) thin films onto Cu-foil using the layer-by-layer (LbL) assembly method. The homogeneous LbL thin films are prepared with the assistance of bifunctional cross-linkers, such as cysteamine, to strengthen the intermolecular interactions between the nano-building blocks. The GO/AgNW LbL thin films possess a highly interdigitated nanostructure that combines the synergistic advantages of the individual building components. The GO layers facilitate the distribution of Li-ionic flux through the films, which promotes the formation of stable solid electrolyte interphase layers. In addition, the AgNW layers provide electrical pathways and serve as nucleation sites for Li─Ag alloy reactions. These combined effects lead to a flat and stable initial Li-deposition, as well as dense and compact Li growth, without significant dendrite formation. The full cell tests show excellent cycle longevity, 430 cycles with an N/P ratio of 3.36 at 1 C and 250 cycles with an N/P ratio of 1.81 at 3 C.

Enhancing reaction kinetics and stabilizing lithium deposition in lithium-sulfur batteries with an FeBr2DME additive

Enhancing reaction kinetics and stabilizing lithium deposition in lithium-sulfur batteries with an FeBr2DME additive

The allure of spherical lithium deposition—realizing the stable cycle of anode-free lithium-metal batteries

The allure of spherical lithium deposition—realizing the stable cycle of anode-free lithium-metal batteries

Lithium Deposition Mechanism under Different Thermal Conditions Unraveled via an Optimized Phase Field Model.

As one of the most important physical fields for battery operation, the regulatory effect of temperature on the growth of lithium dendrites should be studied. In this paper, we develop an optimized phase field model to explore the effect of temperature on the growth of Li dendrites in Li metal batteries. We incorporated full lithium deposition kinetics, including atom diffusion and solid electrolyte interface restriction on interface kinetics, into the model and revealed their significance in determining the transformation of the lithium deposition morphology from moss-like to dendrite-like. We found that a high temperature or dispersed hot spots are more conducive to stable battery operation than a low temperature or concentrated hot spots due to the enhanced diffusion kinetics at the high temperature and the more uniform temperature distribution of dispersed hot spots. We believe our work can provide a useful tool for further exploring the thermal effect on stable lithium metal battery operation.

In Operando Raman Spectroscopy Reveals Li-Ion Solvation in Lithium Metal Batteries.

Inhomogeneous lithium (Li) deposition and unstable solid electrolyte interphase are the main causes of short cycle life and safety issues in Li metal batteries (LMBs). Developing a 3D structured matrix current collector and novel electrolyte are feasible strategies to tackle these issues. Ether-based electrolytes are widely used in LMBs. However, a fundamental understanding of Li-ion coordination and solvent remains incomplete. Here, lithiophilic Ag-Cu mesh is designed as the current collector to boost rapid Li-ion flux and Li metal nucleation. Meanwhile, dimethoxyethane (DME)/dioxolane (DOL) are used as complex solvents to enable lower interfacial resistance. The solvation structures at the interfaces of different collectors with different electrolytes are investigated. By applying in operando Raman spectroscopy, it is demonstrated that bis(trifluoromethylsulfonyl)imide TFSI-and DME molecules are highly coordinated with Li+ compared with DOL molecules. Furthermore, lithiophilic 3D Ag-Cu mesh tunes Li+ solvation/desolvation, resulting in a uniform deposition. The Ag-Cu mesh/Li symmetric cells demonstrate long-term cycling life up to 1200h and Coulombic efficiency of 98.6% over 200 cycles at 1mAcm-2. The Ag-Cu mesh/Li||LiNi0.8Co0.1Mn0.1O2 cells exhibit an initial discharge capacity of 208.7mAhg-1 at 1.0 C with a capacity retention of 76.1% after 500 cycles.

Functional Alloy Collector Capable of Sustainable Lithium Compensation for Anode‐Free Batteries by a Controlled Lithium‐Prestorage Technology

AbstractWith higher energy density and reduced cost, anode‐free battery has attracted great attention from both academic and industry. However, the development of anode‐free batteries is hindered by their poor cycle life due to the continuous irreversible lithium (Li) consumption at the anode side. Here, a surface‐functionalized alloy foil, which can gradually release active lithium to the cell upon cycling, used as the collector for anode‐free batteries is proposed. The alloy foil is prestored with a certain amount of active lithium via a simple wet contacting reaction between the metal foil and liquid lithium source reagent. The prestored lithium amount can be precisely controlled by reagent concentration and contact time. When the foil is used as the anode, its alloyed surface demonstrates a low nucleation barrier for lithium deposition and a more uniform deposition behavior. More importantly, the alloy collector can rationally release active lithium to sustainably compensate for the irreversible Li consumption upon the cycling of a full cell, thus greatly prolonging the cycle life of the anode‐free battery by 10 times. Besides, this technique can be extended to diverse metal collectors demonstrating its broad applicability.

Solvation Regulation of Non‐Flammable Polymer Deep Eutectic Electrolytes with Reinforced Inorganic‐Rich Interphase toward Long‐Cycle Lithium Metal Batteries

AbstractLithium dendrites and flammable carbonate electrolytes present significant challenges to the progress of lithium metal batteries (LMBs), necessitating the urgent development of novel solid electrolytes. Herein, a non‐flammable polymer deep eutectic electrolyte (PDEE) is proposed by encapsulating N‐methylacetamide (NMA)‐based deep eutectic electrolytes within a polymer framework formed by ethoxylated trimethylolpropane triacrylate (ETPTA) via in situ polymerization. The robust Li+‐solvent interaction between the polar groups in NMA and lithium nitrate (LiNO3) significantly improves the solubility of LiNO3. Therefore, an inorganic‐rich LiF, LixN, and LiNxOy solid electrolyte interphase (SEI) is designed by introducing LiNO3 and fluoroethylene carbonate (FEC) into PDEE. The comprehensive characterizations and simulations reveal that moderate LiNO3 addition can modulate the solvated structure of Li+ and result in uniform lithium deposition. The PDEE‐2 (PDEE with 2 wt% LiNO3) exhibits high ionic conductivity (2.5 mS cm−1 at 25 °C) and high Li+ transference number (0.61). The Li||LiFePO4 (LFP) cells maintain cycling stability for 1700 cycles at 2 C, and Li||Ni0.8Co0.1Mn0.1O2(NCM811) cells achieve 300 cycles at 0.5 C with a capacity retention of 86.7%, one of the best results for eutectic‐based polymer electrolytes. This study presents an innovative method for producing stable polymer electrolytes and encourages the utilization of LMBs.

Controllable reconstruction of lignified biomass with molecular scissors to form carbon frameworks for highly stable Li metal batteries.

Lithium metal batteries (LMBs) promise high-energy-density storage but face safety issues due to dendrite-induced lithium deposition, irreversible electrolyte consumption, and large volume changes, which hinder their practical applications. To address these issues, tuning lithium deposition by structuring a host for the lithium metal anode has been recognized as an efficient method. Herein, we report a supercritical water molecular scissor-controlled strategy to form a carbon framework derived from biomass wood. Proximate-supercritical water treatment is used to selectively cleave the β-O-4 bonds in lignin, with the extent of degradation controlled by adjusting the treatment environment's acidity. The enhanced thermal power of supercritical water molecules significantly accelerates the etching rate of lignin, increasing the porosity and permeability of the transformed carbon framework. Experimental results and multi-physics simulations show that the interconnected carbon-based pores and inner skeletal multilevel hierarchical structure facilitate rapid electron and ion transfer during battery operation and enhance electrolyte infiltration. Impressively, the as-obtained lithium metal anode exhibits long-term cycling stability for over 2000 hours at 0.5 mA cm-2 with low voltage overpotential. The water-treated Pinus (WTP)-Li//LiCoO2 full cells maintain a high capacity retention rate of 93.3% and a specific capacity of 142 mA h g-1 at 0.5C for 100 cycles.

Achieving layered deposition of lithium by uniform Li-ion flux distribution in grids

Achieving layered deposition of lithium by uniform Li-ion flux distribution in grids

Dual functional coordination interactions enable fast polysulfide conversion and robust interphase for high-loading lithium-sulfur batteries.

The stable operation of high-capacity lithium-sulfur batteries (LSBs) has been hampered by slow conversion kinetics of lithium polysulfides (LiPSs) and instability of the lithium metal anodes. Herein, 6-(dibutylamino)-1,3,5-triazine-2,4-thiol (DTD) is introduced as a functional additive for accelerating the kinetics of cathodic conversion and modulating the anode interface. We proposed that a coordination interaction mechanism drives the polysulfide conversion and modulates the Li+ solvated structure during the binding of the N-active site of DTD to LiPSs and lithium salts. The results show that DTD effectively promotes the redox of LiPSs and the formation of an inorganic-organic synergistic solid electrolyte interface (SEI). This suppresses the parasitic reaction of LiPSs and confers uniform lithium deposition. Therefore, the capacity decay rate per cycle of the DTD-added LSBs is only 0.066% after 600 cycles at 1C. Moreover, Li-Li symmetric batteries exhibited smaller overpotentials during long cycling and a 41% increment in cycle life. Even with high sulfur loading (5.38 mg cm-2) and a depleted electrolyte sulfur ratio (E/S = 5 μL mg-1), the capacity retention of the battery is 71.5%. This work provides a new reference for elucidating the mechanisms of polysulfide conversion and SEI interface regulation for high-energy-density lithium-sulfur batteries.

Dual-network bacterial cellulose-based separators with high wet strength and a dual ion transport mechanism for uniform lithium deposition

The double network significantly optimizes Li+ transport through the synergistic effect of pore transport within the double network and polymer coordination mechanism, ensuring uniform deposition on the surface of the lithium metal anode.

Ionic covalent organic framework based quasi-solid-state electrolyte for high-performance lithium metal battery

Lithium metal solid-state batteries are promising as rechargeable energy storage devices due to their non-combustible nature, resistance to high temperatures, and non-corrosive properties. However, their widespread application is hindered by low lithium-ion conductivity and poor compatibility at the electrode/electrolyte interface. To address these challenges, two covalent organic frameworks (COFs), one with functional imidazolium groups (Dha-COFim) and one without (Dha-COF), were synthesized. Ionic liquids (ILs) were then incorporated into these COFs to create quasi-solid-state electrolytes (Dha-COFim-IL and Dha-COF-IL). The Dha-COFim, with its ordered porous structure, forms interconnected ion channels that enable fast lithium-ion transport and enhance lithium salt dissociation, achieving excellent thermal stability, high ionic conductivity (1.74 × 10⁻³ S cm⁻1), and a wide electrochemical window at room temperature. Density functional theory (DFT) calculations showed that the fixed imidazolium groups in Dha-COFim enhance interactions with TFSI⁻ anions, improving lithium salt dissociation. This allows free lithium ions to move quickly through the channels with minimal energy loss. Additionally, the formation of a stable SEI layer rich in LiF and Li3N at the lithium metal/electrolyte interface accelerates Li⁺transport, ensuring uniform lithium deposition and superior battery performance. When combined with a LiFePO4 cathode, the LiFePO4‖Dha-COFim-IL‖Li cell delivers high discharge capacity and excellent cycling stability, providing a new strategy for designing quasi-solid-state electrolytes for high-energy-density lithium batteries.

Bifunctional NiCoP nanofiber arrayed on carbon cloth for fast polysulfide conversion and uniform lithium deposition in lithium sulfur batteries

Bifunctional NiCoP nanofiber arrayed on carbon cloth for fast polysulfide conversion and uniform lithium deposition in lithium sulfur batteries

Modulating electrolyte solvation structures with Fe-embedded carbon matrix substrates for robust lithium-metal plating

Carbonized Fe-BTC to Fe@C is utilized as a substrate to enhance lithium deposition by modulating the Li+ solvation structure. This approach significantly improves cycling performance.

In Situ Polymerized Fluorine‐Free Ether Gel Polymer Electrolyte with Stable Interface for High‐Voltage Lithium Metal Batteries

AbstractLithium metal batteries offer increased energy density compared to traditional lithium‐ion batteries. Commercial carbonate‐based electrolytes are incompatible with lithium metal anodes, while ether‐based electrolytes, though more suitable, tend to degrade under high potentials. Here, a fluorine‐free ether‐based gel polymer electrolyte (FEGPE) has been developed via incorporating lithium bis((trifluoromethyl)sulfonyl)azanide (LiTFSI) as lithium salt, 1,2‐dimethoxyethane (DME) and 1,3‐dioxolane (DOL) as solvents, and indium trifluoromethanesulphonate (In(OTF)3) as an initiator. DME is used to promote dissolution of the In(OTF)3 in DOL, along with enhanced ion transport of the FEGPE. Compared to traditional ether‐based liquid electrolytes, the FEGPE demonstrates significantly improved antioxidant decomposition ability at high potentials, stemming from intermolecular hydrogen bond formation and decreased lone‐pair electron activity of ether oxygen. Additionally, the FEGPE reduces the lithium deposition energy barrier and enables a stable electrolyte/electrode interface by forming Li‐In alloys and LiF components in solid electrolyte interphases. In turn, Li|FEGPE|LiFePO4 cells exhibit a high initial capacity of 151 mAh g−1 at 0.5 C, with an outstanding capacity retention of 97% over 300 cycles. For high‐voltage cathodes, Li|FEGPE|LiN0.8iCo0.1Mn0.1O2 cells deliver an initial capacity of 167 mAh g−1 at 1 C, achieving a capacity retention of 75% over 500 cycles.

A Separator with Double Layers Individually Modified by LiAlO2 Solid Electrolyte and Conductive Carbon for High‐performance Lithium–Sulfur Batteries

AbstractThe “shuttle effect” and the unchecked growth of lithium dendrites during operation in lithium–sulfur (Li–S) batteries seriously impact their practical applications. Besides, the performances of Li–S batteries at high current densities and sulfur loadings hold the key to bridge the gap between laboratory research and practical applications. To address the above issues and facilitate the practical utilization of Li–S batteries, the commercial separator is modified with solid electrolyte (nanorod LiAlO2, LAO) and conductive carbon (Super P) to obtain a double coated separator (SPLAOMS). The SPLAOMS can physically barrier polysulfides and accelerate reaction kinetics. In addition, it enhances uniform lithium deposition, boosts ionic conductivity, and increases the utilization of active sulfur substances. The prepared Li–S batteries exhibit excellent cycling stability under harsh conditions (high sulfur loadings and high current densities) with an initial capacity of 733 mAh g−1 and a capacity attenuation of 0.03% per cycle at 5C in 500 cycle life. Under ultra‐high sulfur loading (8.2 mg cm−2), the prepared battery maintains a satisfactory capacity of 800 mAh g−1 during cycling, demonstrating enormous commercial application potential. This study serves as a pivotal reference for the commercialization of high‐performance Li–S batteries.

Additives Capable of Stably Supplying Anions/Cations for Homogeneous Lithium Deposition/Stripping.

One of the important factors leading to lithium dendrites is a slow lithium-ion mass transport and imbalanced distribution of the Li+ concentration and nuclei sites on the anode surface. To achieve uniform lithium deposition during the charge and discharge process, we introduce a homemade new copolymer (with the quaternary ammonium group N3R+I- on its side chain as the main functional group), named P35, as a functional electrolyte additive to regulate the lithium deposition. Theoretical calculations show that under the strong coordinating interaction between I- and N3R+, P35 preferentially adsorbs onto the lithium foil surface, effectively countering the adsorption of lithium salt anions such as PF6-. Moreover, the positive charge carried by the quaternary ammonium salt group of P35 could interact with PF6- to limit their mobility. Consequently, the dipole interaction on lithium ions is diminished, leading to an enhancement in the transport rate and a decrease in the concentration gradient of lithium ions. Furthermore, a more efficient SEI was formed due to the dual charges electrostatic shield formed by N3R+I-. Li-Li symmetric cells and Li-LiFePO4 full cells assembled with electrolytes with P35 exhibit better rate performance, smaller polarization, and smoother deposition morphology in comparison to the cells without the P35 additive.

Self-Selective (220) Directional Grown Copper Current Collector Design for Cycling-Stable Anode-Less Lithium Metal Batteries.

Anode-less lithium metal batteries (ALLMB) are promising candidates for energy storage applications owing to high-energy-density and safety characteristics. However, the unstable solid electrolyte interphase (SEI) formed on anode copper current collector (CuCC) leads to poor reversibility of uneven lithium deposition/stripping. Though the well-known knowledge of lithium salt-derived inorganic-rich SEI (iSEI) benefiting uniform lithium deposition, how to design a lithium salt-philic CuCC with undiscovered salt-philic facet that favors lithium salt adsorption and catalyzing salt decomposition into iSEI, remains unexplored yet. Here, a self-selective and iSEI-catalyzing CuCC design is developed by using lithium salt as surface-controlling agent in CuCC electrodeposition process, self-selecting out and guiding unidirectional Cu(220) facet growth as the most salt-philic facets of CuCC. This self-selected Cu(220) facet promotes the salt adsorption and formation of salt decomposition-derived iSEI in battery, thus improving the lithium plating/stripping coulombic efficiency from 99.25% to 99.50% (stable within 400 cycles), and the capacity decay rate of ALLMB is also reduced by 42.4% within 100 cycles. Practical mass-productivity of this self-selective CuCC for 350 Wh kg-1 pouch-cell fabrication is also demonstrated, providing a new self-selective current collector design strategy for improving selectivity and catalyzation of desired chemical reaction, important for high-selectivity electrochemical reaction system construction.

Visualizing Lithium Deposition and Identifying Two Types of Dendrites in Extreme-Fast-Charging Full Cells across the Entire Lifespan by Operando EPR and EPR Imaging.

Metallic lithium deposition processes in NCM811∥graphite full cells during extreme-fast charging of 4 C (fully charged within 15 min) are detected via operando electron paramagnetic resonance (EPR) and EPR imaging over hundreds of cycles to quantify lithium deposits and visualize their spatial distribution. EPR imaging shows that constant-voltage charge generates loose Li dendrites with divergent growth whereas overcharge leads to long dendrites with vertical growth, and these Li deposits accumulate at the anode edges, which could deplete the Li resource at the cathode edges. Moreover, quantitative EPR indicates that the stripping current correlates to the deposit surface areas, while the reintercalation current depends on the contact areas between plated Li and graphite. Overall, the results of EPR and EPR imaging suggest that the introduction of a relaxation period after extreme-fast charge for Li reintercalation into graphite is important to mitigate the accumulation of dead Li.