Solid Electrolyte Interphase Layer Research Articles

The Regulation of Solid Electrolyte Interphase on Composite Lithium Anodes in Solid‐State Batteries

AbstractSolid‐state lithium metal batteries (SSLMBs) with solid polymer electrolyte (SPE) are highly promising for next‐generation energy storage due to their enhanced safety and energy density. However, the stability of the solid electrolyte interphase (SEI) on the lithium metal/SPE interface is a major challenge, as continuous SEI degradation and regeneration during cycling lead to capacity fading. This article investigates the SEI formation on lithium anodes (l‐SEI) and composite lithium anodes (c‐SEI) in solid‐state lithium metal batteries. The composite anodes form a uniform Li2S‐rich inorganic SEI layer and a thinner organic SEI layer, effectively passivating the interface for enhanced cycling stability. Specifically, the full cells with c‐SEI anodes sustain over 400 cycles at 0.5 C under a high areal capacity of 2.0 mAh cm−2. Moreover, the reversible high‐loading solid‐state pouch cells exhibit exceptional safety even after curling and cutting. These findings offer valuable insights into developing composite electrodes with robust SEI for solid‐state polymer‐based lithium metal batteries.

Anion-Tailored EDLInduced Triple-Layer SEIon High-Capacity Anodes Enabling Fast-Charging and Durable Sodium-Storage.

High-capacity electrodes facea great challengeofcyclingstability due to particle fragmentation induced conductive network failure and accompanied by sustainedelectrolyte decompositionfor repeatedly build solid electrolyte interphase (SEI).Herein,Se-solubility induced Sex2-as self-adjustment electrolyte additive to regulate electric double layer (EDL) for constructingnovel triple-layer SEI(inner layer:Se; medium layer: inorganic; outer layer: organic) on high-capacityFeS2anode as an example for achievingstable and fast sodium storage. In detail, Sex2-in-situgeneratedat 1.30V (vs.Na+/Na)andwas preferentially adsorbedonto EDLof anode,then convertedto Se0asinner layer of SEI. In addition, the Sex2-causesanion-enhanced Na+solvation structure couldproduce more inorganic (Se0, NaF)andless organic SEI components.The uniquetriple-layer SEIwith layer-by-layer dense structure alleviate the excessive electrolyte consumption with less gas evolution. As a result, the anode delivered long-lifespan at 10 A g-1(383.7 mAh g-1, 6000 cycles, 93.1%, 5 min/cycle). TheSe-induced triple-layer SEIcould be also be formed on high-capacity SnS2anode.This work provides a novel SEI modelby anion-tailored EDL towards stable sodium-storage of high-capacity anode forfast-charging.

Iodine Boosted Fluoro-Organic Borate Electrolytes Enabling Fluent Ion-conductive Solid Electrolyte Interphase for High-Performance Magnesium Metal Batteries.

Rechargeable magnesium batteries are regarded as a promising multi-valent battery system for low-cost and sustainable energy storage applications. Boron-based magnesium salts with terminal substituent fluorinated anions (Mg[B(ORF)4]2, RF = fluorinated alkyl) have exhibited impressive electrochemical stability. Nevertheless, their deployment is hindered by the complicated synthesis routes and the surface passivation of Mganode. Herein, we report the design of an advanced electrolyte formulation comprised of B(HFIP)3and I2in 1,2-dimethoxyethane (DME), which eventually convert into a Mg[B(HFIP)4]2/DME-MgI2 electrolyte system upon interacting with Mg anode. The Mg anode reacts with I2 and the electron-accepting B(HFIP)3, leading to the in-situ formation of a solid-electrolyte interphase layer composed of MgF2 and MgI2 species that can facilitate fast and stable Mg plating/stripping. Compared with the pristine Mg[B(HFIP)4]2/DME electrolyte, the Mg[B(HFIP)4]2/DME-MgI2 electrolyte exhibited superior electrochemical performance including an ultra-low overpotential (~80 mV), high Coulombic efficiency and a long-cycling period over 1500 h. In result, the rechargeable magnesium batteries with Mg[B(HFIP)4]2/DME-MgI2 electrolyte and Mo6S8 cathode show outstanding compatibility, rapid kinetics, and stable cyclability for over 1200 cycles, surpassing all previously reported boron-based electrolytes. This work introduces a promising halogen-enhancement strategy for boron-based Mg-ion electrolytes and is pivotal for the advancement and optimization of multi-valent secondary batteries.

Effective Stabilization of Organic Cathodes Through Formation of a Protective Solid Electrolyte Interface Layer via Reduction.

2,5-Dihydroxy-1,4-benzoquinone (DHBQ) is a promising cathode material, but its high solubility in electrolytes leads to rapid capacity degradation. This study investigates the dilithium salt of DHBQ, Li2DHBQ, as a cathode material for lithium-ion batteries (LIBs). Despite minimal solubility, Li2DHBQ cathodes suffer rapid capacity decay due to severe morphological damage within the voltage range of 1.5-3.0 V. To stabilize morphology, we promoted a protective solid electrolyte interphase (SEI) layer on Li2DHBQ particles by lowering the discharge cutoff voltage. Cycling the battery with a 0.5 V discharge cutoff voltage achieved an optimal SEI layer, significantly improving Li2DHBQ's morphological stability. Consequently, the battery maintained 170 mAh g-1 with a low decay rate of 0.16% within a voltage range of 0.5-3.0 V after 200 cycles at 500 mA g-1. Furthermore, initial cycling at a 0.5 V discharge cutoff for 20 cycles to form an SEI layer, followed by cycling at a normal 1.5 V discharge cutoff, retained a higher capacity of 187 mAh g⁻¹ after 200 cycles. This study demonstrates the effectiveness of forming a cathode SEI layer at low discharge voltages as a new approach to stabilizing organic cathode materials.

Electrode/Electrolyte Optimization-Induced Double-Layered Architecture for High-Performance Aqueous Zinc-(Dual) Halogen Batteries

HighlightsA double-layered protective film based on zinc-based coordination compound and ZnF2-rich solid electrolyte interphase layer has been successfully fabricated on the zinc metal anode via electrode/electrolyte synergistic optimization.The double-layered architecture can effectively modulate Zn2+ flux and suppress the zinc dendrite growth, thus facilitating the uniform zinc deposition.The as-developed zinc-(dual) halogen batteries based on double-layered protective film can present high areal capacity and satisfactory cycling stability.

Machine Learning-Assisted Bayesian Optimization for the Discovery of Effective Additives for Dendrite Suppression in Lithium Metal Batteries.

In the pursuit of enhancing the performance and safety of lithium (Li)-metal batteries, the discovery of effective electrolyte additives to suppress Li dendrites has emerged as a paramount objective. In this study, we employ an inverse design strategy to identify potential additives for dendrite mitigation. Two key mechanisms, namely, the formation of robust solid electrolyte interphase layers and the leveling mechanism, serve as the foundation for our investigation. Our inverse design strategy is guided by molecular properties such as the lowest unoccupied molecular orbital energy and interaction energy upon Li surface adsorption. An active learning process utilizing Bayesian optimization (BO) was utilized to identify potential molecules with ideal properties. Through this screening process, we uncover a collection of 62 molecules with the potential to act as SEI-forming additives, along with 106 molecules for leveling additives, both surpassing the performance of established additives reported in the literature. This work highlights the potential of BO methods in computationally based inverse design of materials for many applications, and the discovered additives could potentially boost the commercialization of Li-metal batteries.

First‐Principles Molecular Dynamics Study on Reductive Stability of High Concentration Electrolyte on Zn Doped Cu Current Collector Surface

AbstractIn enhancing the lifespan of anode‐free Li metal batteries (AFLMBs), current collector (CC) engineering is crucial for achieving uniform and dendrite‐free lithium deposition. The commonly used copper (Cu) CC is unsatisfactory because of its poor lithiophilicity. Here, we consider Zn doping on the Cu CC surface (Zn−Cu) and explore the reductive stability of a high‐concentration electrolyte (HCE), consisting of 3.6 M Lithium Hexafluorophosphate (LiPF6) salt in a mixture of ethylene carbonate (EC) and diethylcarbonate (DEC), on the Zn−Cu (111) surface (HCE|Zn−Cu) using density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. The interfacial reactions in the HCE|Zn−Cu system are compared to those on the pristine Cu (111) surface (HCE|Cu). We have also studied the effect of electron‐rich environments on the decomposition mechanism of the HCE mixture on both the CC surfaces. It is found that the HCE mixture is electrochemically stable on both Cu and Zn−Cu surfaces in a neutral environment. However, under electron‐rich conditions, only one DEC molecule has decomposed upon contact with the Cu CC surface, while the two PF6− anion groups from Li salts have decomposed much faster (within 100 fs) when the HCE mixture interacts with the Zn−Cu surface. Our results indicate that Zn doping suppresses undesirable solvent decomposition and improves the quality of the solid electrolyte interphase (SEI) layer.

Room-temperature ionic liquid electrolytes for carbon fiber anodes in structural batteries

Structural batteries require thermally stable electrolytes paired with carbon fibers (CFs), which offer advantages of lightweight, high mechanical strength, and good electrical conductivity. This work evaluated various room-temperature ionic-liquids (RTILs) as compatible electrolytes for CF anodes and LiFePO4 (LFP) cathodes on CFs. This LFP/CF full-cell design eliminates Cu and Al current-collectors, potentially enhancing gravimetric energy and reducing costs. Among various RTILs, LiTFSI in N-propyl-N-methylpyrrolidinium (PYR13) – bis(fluorosulfonyl)imide (FSI) offered promising LFP/CF full-cell performances, attributed to the formation of solid electrolyte interphase (SEI) layer on the CF anode with components such as Li2Sx, Li2S–SO3, LiF, LixFy and F–SO2, identified through X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) analyses further confirmed the electrochemical stability of the SEI layer on CF anodes. The LFP/CF cell delivered an initial capacity of 119 mAh/g and relatively high Coulombic efficiency when using the 1 M LiTFSI in PYR13-FSI. CF cycled in different electrolytes exhibit varying mechanical properties with up to 10.08 % loss in tensile strength, which may be related to CF surface degradation during cycling. The 1 M LiTFSI in PYR13-FSI is non-flammable, offering a significant thermal safety. This work successfully demonstrated the significant potential of 1 M LiTFSI in PYR13-FSI RTILs, which enables the use of CF as both an anode active material and cathode current collector for structural battery applications.

Achieving stable lithium metal anode via constructing lithiophilicity gradient and regulating Li3N-rich SEI

Three-dimensional (3D) current collectors are studied for the application of Li metal anodes in high-energy battery systems. However, they still suffer from the preferential accumulation of Li on the outermost surface, resulting from an inadequate regulation of the Li+ transport. Herein, we propose a deposition regulation strategy involving the creation of a 3D lithiophilicity gradient structure of MoN on Cu3N nanowire-grown Cu foam (MCNCF) to induce a “bottom-up” Li deposition. During the initial Li deposition, the reaction between Li and Cu3N leads to the formation of Li3N while the lithiophilic MoN located at the bottom promotes the downward Li+ migration, resulting in the generation of a Li3N gradient. Such a “bottom-up” Li3N distribution results in the formation of a stable and Li3N-rich solid electrolyte interphase layer, facilitating the Li⁺ transport and promoting a uniform Li nucleation. Computational simulations and experimental results corroborate the preferential deposition of Li on the bottom of the substrate, leading to a uniform Li nucleation and growth throughout the electrode. The MCNCF electrode offers a significantly improved reversibility of the Li deposition, achieving a lifespan of more than 1200 h at a current density of 1 mA cm−2 in symmetric Li||Li cells. Furthermore, full-cells incorporating MCNCF@Li as the negative electrode and LiFePO4 cathodes exhibit outstanding electrochemical performance with a capacity retention of over 99.5 % after 250 cycles at 1 C, which significantly surpasses the performance achieved with CF@Li or CCF@Li electrodes. This innovative design strategy for 3D metallic current collectors, featuring a lithiophilicity gradient, provides new perspectives for the development of stable Li metal anodes and, as a result, for the advancement of Li-metal batteries.

Constructing stable solid electrolyte interphases to enhance the calendar life of anode-free lithium metal batteries

Advancement of anode-free lithium metal batteries (AFLMBs) has been appreciated due to their exceptional volumetric energy density and manufacturing simplicity. However, AFLMBs suffer from poor cycle performance due to the absence of excess lithium and current research lacks an understanding of lithium corrosion and calendar aging in AFLMBs. Here, we investigate the practical effects of chemical and galvanic corrosion on battery performance (calendar life) through a modified full-cell cycling experiment. The impact of galvanic corrosion is negligible, whereas chemical corrosion during a rest period reduces the capacity retention (CR) from 47% to 32% over 100 cycles. Consequently, a corrosion control strategy is implemented, substituting 1,2-dimethoxyethane with 1,2-dimethoxypropane (DMP), which has weaker lithium ion solvation properties due to its inductive effect. This approach results in the formation of a Li2O-rich solid-electrolyte interphase (SEI) layer, which effectively prevents direct contact of lithium with the electrolyte and the formation of additional SEI layers. Consequently, the decrease in CR due to chemical corrosion is considerably mitigated in DMP-based electrolyte, with only a slight decrease from 51% to 49%. This study provides insights into lithium corrosion in practical AFLMBs and offers guidelines for designing less-corrosive electrolytes to improve AFLMB performance for diverse industrial applications as energy-storage devices.

Facile Electrodeposition Method for Constructing Li2S as Artificial Solid Electrolyte Interphase for High-Performance Li Metal Anode.

Designing current collectors and constructing efficient artificial solid electrolyte interphase (SEI) layers are promising strategies for achieving dendrite-free Li deposition and practical applications in Li metal batteries (LMBs). Electrodeposition is advantageous for large-scale production and allows the direct formation of current collectors without binders, making them immediately usable as electrodes. In this study, an adherent Cu2S thin-layer on Cu foil is synthesized through anodic electrodeposition from a Na2S solution in a one-step process, followed by the generation of Li2S layers as artificial SEI layers via a conversion reaction (3DLi2S-Cu foil). The Li2S layers move from the 3D Cu surface to the deposited Li surface, facilitating uniform and dense Li deposition. The 3DLi2S-Cu foil structure demonstrates stable cycling performance over 350 cycles in an asymmetric cell, with a capacity of 1 mAh cm-2 at 1 mA cm-2. Moreover, symmetric cells with 5 mAh cm-2 of deposited Li exhibit a stable cycle life for over 1200 h. When paired with commercial LiFePO4 (LFP), the full cells show substantially enhanced cyclability, regardless of the amount of deposited Li. This study provides new insights into the construction of artificial SEIs for facilitating commercial applications.

Unveiling the Role of Filler Characteristics in Enhancing the High-Voltage Performance of Succinonitrile-Based Solid-State Lithium-Metal Batteries.

For exploiting high-energy lithium-metal batteries, it is of utmost importance to develop electrolytes that possess exceptional ionic conductivity and an extensive electrochemical stability range. In this study, 3D PAN nanofibers and polymer electrolytes incorporating various inorganic fillers with different Lewis acid-base properties were fabricated. PAN@Al-SSE exhibits exceptional ionic conductivity (0.48 mS·cm-2 at room temperature), a high Li+ transference number (0.41), and a wide electrochemical window (5.26 V). The device is able to operate stably in Li symmetric cells for more than 1000 h under a potential of 0.03 V under a current density of 0.2 mA·cm-2. Besides, the groundbreaking technology equips high-voltage Li-LiCoO2 solid-state batteries with exceptional cycling performance (91.3% and 82.1% retention after 100 cycles at 0.2 and 1 C, respectively) at room temperature. Mechanistic studies indicate that the Lewis acid-base properties of surface fillers are instrumental and crucial to form a stable solid-electrolyte interphase layer. γ-Al2O3, in particular, with more Lewis acid sites, ensures the dissociation of LiTFSI and induces the excessive decomposition and polymerization of succinonitrile. There exists an equilibrium effect between dissociation and polymerization in a succinonitrile-based solid electrolyte, which plays a critical role in improving the manifestation of succinonitrile-based solid-state lithium cells, especially under high-voltage conditions.

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.

Molecular Engineering Chemical Pre-lithiation Reagent with Low Redox Potential for Graphite Anode Enables High Coulombic Efficiency.

Graphite (Gr) is a low-cost and high-stability anode for lithium-ion batteries (LIBs). However, Gr anode exhibits an obstinate drawback of low initial Coulombic efficiency (ICE), owing to the active lithium loss for the solid electrolyte interphase (SEI) layer. Herein, a straightforward and effective chemical pre-lithiation strategy is proposed to compensate for the lithium loss. A molecular engineering phenanthrene-based lithium-arene complex (Ph-based LAC) reagent is designed by density functional theory (DFT) calculations. The engineering Ph-based reagent enhances the stability of the π-electron system and the electron-donating capacity, resulting in a reduced redox potential to facilitate lithium transfer. The electrochemical distinct of the Ph-based reagent is illustrated, the prelithiation process in a low Li-insertion platform, and the lithiation degree is controllable with the dipping time (ICE = 102%, 3min). Notably, a denser and homogeneous SEI layer has pre-formed to enhance the Li+ transport and interface stability. Moreover, the lithium-ion full batteries assemble with LiFePO4 and NCM811 cathode, which exhibits high ICE (96.5% and 90.3%) and energy density (310 and 333Whkg-1). These findings present a facile and controllable pre-lithiation strategy to compensate for the lithium of LIBs, providing new valuable insights into the design and optimization of battery manufacture.

Dendrite-Free Lithium Batteries Enabled by an Artificial High-Dielectric Biopolymer Interface Layer.

Lithium (Li) metal batteries face challenges, such as dendrite growth and electrolyte interface instability. Artificial interface layers alleviate these issues. Here, cellulose nanocrystal (CNC) nanomembranes, with excellent mechanical properties and high specific surface areas, combine with polyvinylidene-hexafluoropropylene (PVDF-HFP) porous membranes to form an artificial solid electrolyte interphase (SEI) layer. The porous structure of PVDF-HFP equalizes the electric field near metallic lithium surfaces. The high mechanical modulus of CNC (6.2 GPa) effectively inhibits dendrite growth, ensures the uniform flow of lithium ions to the lithium metal electrode, and inhibits the growth of lithium dendrites during cycling. The synergy of high polarity β-phase poly(vinylidene fluoride) (PVDF) and CNC provides over 1000 h of stability for Li//Li batteries. Moreover, Li//LiFePO4 (LFP) full cells with this artificial protective layer perform well at 5 C, showcasing the potential of this film in lithium metal batteries.

Comparative Study of High Voltage Spinel∥Lithium Titanate Lithium‐ion Batteries in Ethylene Carbonate Free Electrolytes

AbstractA persistent obstacle towards the realization of high voltage cathodes is electrolyte instability where oxidation and transition metal dissolution manifest in rapid capacity failure with both issues connected to the presence of ethylene carbonate in the electrolyte. Here, alternative electrolyte co‐solvents are investigated and compared, where the cyclic carbonate is replaced with sulfones ethyl methyl sulfone (EMS) and tetra methylene sulfone (TMS) and fluoroethylene carbonate (FEC). The best full cell performance was observed for cells cycled in a FEC/EMC (3/7) and FEC/EMC (1/1) electrolytes which exhibited 84–85 % capacity retention after 500 cycles. TMS/EMC (3/7), was determined to be the best performing sulfone electrolyte and maintained 71 % capacity after 500 cycles. Post‐mortem XPS analysis indicated different film forming mechanisms for the respective co‐solvent. A thicker cathode electrolyte interphase (CEI) on the LNMO was observed for the FEC containing electrolytes (relative to when TMS was used as the co‐solvent) indicating more effective passivation of the reactive cathode surface which correlated well with the enhanced cycling stability observed. For LTO, more evidence of transition metal migration and a thicker solid electrolyte interphase (SEI) layer was observed for the sulfone electrolyte suggesting more parasitic anode‐electrolyte interactions and an inability to mitigate Mn2+/Ni2+ crosstalk.

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.

Dynamic Processes at the Electrode‐Electrolyte Interface: Implications for Lithium Deposition Stability

AbstractLithium (Li) metal is a promising negative electrode material for high‐energy‐density rechargeable batteries, owing to its exceptional specific capacity, low electrochemical potential, and low density. However, challenges such as dendritic Li deposits, leading to internal short‐circuits, and low Coulombic efficiency hinder the widespread adoption of lithium‐metal batteries (LMBs). These issues stem from the morphological instability of Li deposition, influenced by dynamic processes at the electrolyte|Li interface. Understanding the interplay between electrolyte properties, interfacial kinetics, and Li deposition stability is crucial yet challenging due to their simultaneous occurrence and the complexity of the solid electrolyte interphase (SEI) layer. This review discusses three key dynamic processes influencing Li deposition: desolvation of Li+ ions, transport through the SEI, and electrochemical reduction. The effects of electrolyte properties on these processes and their interplay with electroplating stability are discussed, highlighting contradictions in the literature and proposing explanations for the discrepancies. Despite numerous reviews on SEI structure and composition effects, this article emphasizes the kinetic aspects at interfaces, aiming to provide clarity and direction for future research in achieving stable Li deposition in LMBs.

Magnetically oriented nanosheet interlayer for dynamic regeneration in lithium metal batteries

Lithium (Li) metal has been recognized as a promising anode to advance the energy density of current Li-based batteries. However, the growth of the solid-electrolyte interphase (SEI) layer and dendritic Li microstructure pose significant challenges for the long-term operation of Li metal batteries (LMBs). Herein, we propose the utilization of a suspension electrolyte with dispersed magnetically responsive nanosheets whose orientation can be manipulated by an external magnetic field during cell operation for realizing in situ regeneration in LMBs. The regeneration mechanism arises from the redistribution of the ion flux and the formation of an inorganic-rich SEI for uniform and compact Li deposition. With the magnetic-field-induced regeneration process, we show that a Li||Li symmetric cell stably operates for 350 h at 2 mA cm-2 and 2 mA h cm-2, ~5 times that of the cell with the pristine electrolyte. Furthermore, the cycling stability can be significantly extended in the Li||NMC full cell of 3 mA h cm-2, showing a capacity retention of 67% after 500 cycles at 1C. The dynamic Li metal regeneration demonstrated here could bring useful design considerations for reviving the operating cells for achieving high-energy, long-duration battery systems.

UV‐Triggered In Situ Formation of a Robust SEI on Black Phosphorus for Advanced Energy Storage: Boosting Efficiency and Safety via Rapid Charge Integration Plasticity

AbstractBlack phosphorus (BP) emerges as a highly promising electrode material for next generation of energy‐storage systems. Yet, its full potential is hindered by the instability of the solid‐electrolyte interphase (SEI) and the inflammability of its liquid systems. Here a pioneering UV‐induced in situ strategy is introduced for SEI construction, which leverages rapid electron supply to fracture sulfur‐dihalide bonds. This technique yields internal dihalide inorganic components and an external polymer segment, with any excess organic material being purged through pores. The (E)‐2‐chloro‐4‐((3′‐chloro‐4′‐hydroxyphenyl)diazinyl)phenyl acrylate (CA), with chlorine‐terminated groups, is initially in situ transformed into a flame‐retardant phenyl carboxylic acid (PCA), and then encapsulated within an ultrathin BP nanostructure, further nested in nitrogen (N), boron (B) co‐doped carbon (C) sheets that accommodate cobalt (Co) single atoms/nanoclusters (Co‐NBC). The Co‐NBC@BP@PCA construct demonstrates an impressive initial Coulombic efficiency (ICE) of 99.1% and maintains exceptional stabilities in terms of mechanical, chemical, and electrochemical performancecritical for prolonged cycle and calendar life. This research sheds light on the interplay between the rapid charge supply integrated in situ plasticity (RSIP) approach and the proactive establishment of an artificial SEI layer, offering profound insights into enhancing the durability and providing a solid foundation for advancements in energy storage technology.