Robust Solid Electrolyte Interphase Research Articles

Highly-solvating Electrolyte Enables Mechanically Stable and Inorganic-rich Cathode Electrolyte Interphase for High-performing Potassium-ion Batteries.

Cathode-electrolyte interphase (CEI) is crucial for the reversibility of rechargeable batteries, yet receives less attention compared to solid-electrolyte interphase (SEI). The prevalent weakly-solvating electrolyte is usually proposed from the standing point of obtaining robust SEI, however, the resultant weak ion-solvent interaction gives rise to excessive free solvents and forms thick CEI with high kinetic barriers, which is disadvantageous for interfacial stability at the high working voltage. Herein, we report a highly-solvating electrolyte to immobilize free solvents by generating stable ternary complexes and facilitate the growth of homogeneous and ultrathin CEI to boost the electrochemical performances of potassium-ion batteries (PIBs). Through time-of-flight secondary ion mass spectrometry and cryogenic transmission electron microscopy, we reveal that the deliberately coordinated complexes are the key to forming mechanically stable and inorganic-rich CEI with superior diffusion kinetics for high-performing PIBs. Coupling with a K0.5MnO2 cathode and a soft carbon (SC) anode, we achieve a high energy density (202.3Wh kg-1) with an exceptional cycle lifespan (92.5% capacity retention after 500 cycles) in a SC||K0.5MnO2 full cell, setting new performance benchmarks for PIBs. This article is protected by copyright. All rights reserved.

Self‐Extinguishing and Low‐Cost Quasi‐Solid Polymer Electrolyte for Room Temperature Lithium Metal Batteries

Most modification strategies of polyethylene oxide (PEO)‐based solid polymer electrolyte focus on improving the room temperature ionic conductivity, while disregarding its inherent flammability that poses substantial safety hazard. Herein, a self‐extinguishing quasi‐solid‐state polymer electrolyte (PTTF‐SPE), which combines excellent room temperature electrochemical properties and high safety, has been developed by introducing triethyl phosphate (TEP) as a low‐cost and highly effective flame retardant. The cross‐linking structure derived from ‐CH2‐CH2‐O‐ segments of tetramethylene glycol dimethyl ether (TEGDME) and PEO makes a contribution to a high amorphous state of polymer. A robust solid electrolyte interphase (SEI) formed by preferential decomposition of fluoroethylene carbonate (FEC) that acts as a film‐forming additive, which can prevent TEP from degradation at lithium metal anode. The optimized PTTF‐SPE exhibits high ionic conductivity (0.54×10‐3 S/cm) and lithium transference number (0.71) at room temperature. The LiFePO4||Li battery demonstrates excellent cycle life over 500 cycles at 0.5 C with a high average discharge capacity of 131 mAh/g. A symmetric Li||Li battery that operating for 850 hours indicates a good compatibility of PTTF‐SPE towards lithium metal. This work provides a new idea for developing high‐energy‐density and high‐safety lithium‐metal batteries (LMBs) for room temperature.

Superhalide-Anion-Motivator Reforming-Enabled Bipolar Manipulation toward Longevous Energy-Type Zn||Chalcogen Batteries.

Neutrophilic superhalide-anion-triggered chalcogen conversion-based Zn batteries, despite latent high-energy merit, usually suffer from a short lifespan caused by dendrite growth and shuttle effect. Here, a superhalide-anion-motivator reforming strategy is initiated to simultaneously manipulate the anode interface and Se conversion intermediates, realizing a bipolar regulation toward longevous energy-type Zn batteries. With ZnF2 chaotropic additives, the original large-radii superhalide zincate anion species in ionic liquid (IL) electrolytes are split into small F-containing species, boosting the formation of robust solid electrolyte interphases (SEI) for Zn dendrite inhibition. Simultaneously, ion radius reduced multiple F-containing Se conversion intermediates form, enhancing the interion interaction of charged products to suppress the shuttle effect. Consequently, Zn||Se batteries deliver a ca. 20-fold prolonged lifespan (2000 cycles) at 1 A g-1 and high energy/power density of 416.7 Wh kgSe-1/1.89 kW kgSe-1, outperforming those in F-free counterparts. Pouch cells with distinct plateaus and durable cyclability further substantiate the practicality of this design.

A scalable Li-Al-Cl stratified structure for stable all-solid-state lithium metal batteries.

Sulfides are promising electrolyte materials for all-solid-state Li metal batteries due to their high ionic conductivity and machinability. However, compatibility issues at the negative electrode/sulfide electrolyte interface hinder their practical implementation. Despite previous studies have proposed considerable strategies to improve the negative electrode/sulfide electrolyte interfacial stability, industrial-scale engineering solutions remain elusive. Here, we introduce a scalable Li-Al-Cl stratified structure, formed through the strain-activated separating behavior of thermodynamically unfavorable Li/Li9Al4 and Li/LiCl interfaces, to stabilize the negative electrode/sulfide electrolyte interface. In the Li-Al-Cl stratified structure, Li9Al4 and LiCl are enriched at the surface to serve as a robust solid electrolyte interphase and are diluted in bulk by Li metal to construct a skeleton. Enabled by its unique structural characteristic, the Li-Al-Cl stratified structure significantly enhances the stability of negative electrode/sulfide electrolyte interface. This work reports a strain-activated phase separation phenomenon and proposes a practical pathway for negative electrode/sulfide electrolyte interface engineering.

Lithium fluorosulfonate-induced low-resistance interphase boosting low-temperature performance of commercial graphite/LiFePO4 pouch batteries

The performance of Li-ion batteries (LIBs) at sub-ambient temperatures is limited by the resistive interphases due to electrolyte decomposition, particularly on the anode surface. In this study, lithium fluorosulfonate (LFS) was added to commercial electrolytes to enhance the low-temperature electrochemical performance of LiFePO4 (LFP)/graphite (Gr) pouch cells. The addition of LFS significantly reduced the charge transfer resistance of the anode, substantially extending the cycle life and discharge capacity of commercial LFP/Gr pouch cells at −10 and −30 °C. Compared with the capacity retention rate of the baseline electrolyte at −10 °C (80 % after 25cycles), the capacity retention rate of the LFS electrolyte after 100 cycles under 0.5 C/0.5 C was retained at 94 %. Further mechanistic studies showed that the LFS additive induced the formation of a solid electrolyte interphase (SEI) film comprising inorganic-rich LiF, Li2SO4, and additional organic fluorides and sulfides to maintain good stability at the Gr/electrolyte interface during low-temperature operation. LFS suppressed electrolyte decomposition by forming a robust and low-resistance SEI film on the anode. These results demonstrate that LFS is a promising electrolyte additive for low-temperature LFP/Gr pouch cells.

Borate modified Co-free LiNi0.5Mn1.5O4 cathode material: A pathway to superior interface and cycling stability in LNMO/graphite full-cells

Cobalt-free LiNi0.5Mn1.5O4 (LNMO) holds great promise as a next-generation cathode material for high-energy and high-power density lithium-ion batteries (LIBs), making it a key contender for large-scale energy storage systems (ESS) and transportation applications. Despite its potential, the commercial utilization of LNMO has been impeded by its rapid capacity deterioration attributed to an unstable LNMO/electrolyte interface caused by the intrinsically high operating voltage of LNMO. Here, we present a pragmatic and scalable strategy to improve the LNMO/electrolyte interface through borate-based surface coating of the LNMO. Optimizing the coating process yielded high-rate capability and stable LNMO/electrolyte interface analyzed by extended float tests. Borate-LNMO materials show superior cycling stability at 25 °C and 45 °C, attributed to a robust cathode electrolyte interphase (CEI) formation. The bare LNMO and 0.25-B2O3-LNMO demostrated a cycling stability of around 41.20 % and 62.50 % respectively after 1000 cycles in LNMO/graphite full-cells. Post-mortem X-ray photoelectron spectroscopy (XPS) analysis revealed fewer side reaction products on borate-LNMO cathodes compared to bare LNMO. Additionally, scanning electron microscopy (SEM) revealed a thicker and denser solid-electrolyte interphase (SEI) layer on cycled graphite anodes from bare LNMO cells, while a thin and robust SEI was observed on graphite from borate-LNMO cells. Finally, we have conclusively demonstrated that the primary aging mechanism in LNMO/graphite full cells stems from the instability at the LNMO/electrolyte or/and graphite/electrolyte interface, rather than material-related degradation phenomenon. These compelling outcomes underscore the potential of cathode material surface coating in general and especially of borate coating on LNMO as a promising and cost-effective enabler for the use of LNMO in next-generation LIBs.

Biomass-derived polymer as a flexible “zincophilic–hydrophobic” solid electrolyte interphase layer to enable practical Zn metal anodes

Aqueous zinc ion batteries (AZIBs) face significant challenges stemming from Zn dendrite growth and water-contact attack, primarily due to the lack of a well-designed solid electrolyte interphase (SEI) to safeguard the Zn anode. Herein, we report a bio-mass derived polymer of chitin on Zn anode (Zn@chitin) as a novel and robust artificial SEI layer to boost the Zn anode rechargeability. The polymeric chitin SEI layer features both zincophilic and hydrophobic characteristics to target the suppressed dendritic Zn formation as well as the water-induced side reactions, thus harvesting a dendrite-free and corrosion-resistant Zn anode. More importantly, this polymeric interphase layer is strong and flexible accommodating the volume changes during repeated cycling. Based on these benefits, the Zn@chitin anode demonstrates prolonged cycling performance surpassing 1300 h under an ultra-large current density of 20 mA cm−2, and a long cycle life of 680 h with a record-high zinc utilization rate of 80 %. Besides, the assembled Zn@chitin/V2O5 full batteries reveal excellent capacity retention and rate performance under practical conditions, proving the reliability of our proposed strategy for industrial AZIBs. Our research offers valuable insights for constructing high-performance AZIBs, and simultaneously realizes the high-efficient use of cheap biomass from a “waste-to-wealth” concept.

Diethylene glycol reduced the water activity of aqueous electrolyte via regulating interphase chemistry for highly durable Zinc-ion batteries

The uncontrollable dendrite growth and parasitic side reactions of Zn lead to poor cycling stability, hindering the practical application of aqueous zinc-ion batteries. Here, we develop a new hybrid electrolyte with zinc trifluoromethanesulfonate dissolved in water and co-solvent diethylene glycol (DEG). DEG can not only alter the Zn2+ solvation structure with the co-participation of DEG and anion to reduce active water molecules, but also interrupt the hydrogen-bond network of the original water. DEG is more easily absorbed on Zn surface than H2O to regulate electric double layer. Based on these unique effects, DEG can regulate interface chemistry, forming a robust solid electrolyte interphase and adjusting Zn2+ stripping/plating behaviors, which suppress side reactions and dendrite growth. Their synergetic effect results in the great improved cycling stability of Zn anode with 5000 h in symmetric cell at 1 mA cm−2 and 1 mAh cm−2. The work shed light on the design of high-performance aqueous electrolyte to advance zinc-ion batteries.

1,3,6-Hexanetricarbonitrile as electrolyte additive to inhibit sodium dendrites in sodium-metal batteries

Sodium-metal batteries (SMBs) offer substantial competitiveness owing to their wide elemental distribution and high specific capacity. However, SMBs face safety issues such as unstable properties of the Solid Electrolyte Interphase (SEI) layer due to irregular sodium dendrites. In this paper, we constructed a stable and uniform SEI layer by introducing the 1,3,6-Hexanetricarbonitrile (HTCN) electrolyte additive, replacing the conventional, insoluble nitrate. HTCN facilitates the generation of substances like Na3N with high electrical conductivity on the Na anode surface. This accelerates Na+ shuttling and provides high-flux nucleation sites. Molecular dynamics simulations were employed to elucidate the solvated structure of electrolyte and radial distribution of Na+ after HTCN addition. Moreover, in-situ optical microscopy revealed a stable and robust SEI layer, effectively inhibiting the disorderly growth of sodium dendrites. The superior cycling performance of the Na3V2(PO4)3 (NVP)/Na full cell further demonstrates the addition of HTCN.

Au-embedded mesoporous molecular sieve enables robust organic/inorganic hybrid solid electrolyte interphase for high-performance lithium metal batteries

The solid electrolyte interphase (SEI) determines the lithium (Li) deposition behavior for long-term lithium metal batteries. However, the naturally formed fragile SEI would cause the nonuniform lithium deposition and random dendrite growth due to weak interaction of the heterogeneous distributed inorganic and organic species. Herein, we designed Au-embedded mesoporous molecular sieve as an electrolyte modifier to feasibly form a robust organic/inorganic hybrid SEI. Such hybrid SEIs, composed of Si-O interlinked polycarbonates (poly(CO3)) which is derived from the Au-induced electrocatalytic polymerization of EC (ethylene carbonate), possess an ultrahigh Young’s modulus of 11.6 GPa, achieving uniform lithium deposition and suppression of lithium dendrites. Assembled by the Au@MCM-41-modified electrolyte, the Li||Li symmetrical cells exhibit a recyclable behavior of Li deposition/dissolution over 900 h at 0.5 mA cm−2, and the Li||LFP (LiFePO4) full cells maintain a high capacity of 123 mAh g−1 even after 300 cycles at 1.0 C. This work explores a new route to in situ develop a robust and effective SEI for prospective lithium metal batteries in practical application and social requirement.

Eutectogel Electrolyte Constructs Robust Interfaces for High-Voltage Safe Lithium Metal Battery.

Dramatic growth of lithium dendrite, structural deterioration of LiCoO2 (LCO) cathode at high voltages, and unstable electrode/electrolyte interfaces pose significant obstacles to the practical application of high-energy-density LCO||Li batteries. In this work, a novel eutectogel electrolyte is developed by confining the nonflammable eutectic electrolyte in a polymer matrix. The eutectogel electrolyte can construct a robust solid electrolyte interphase (SEI) with inorganic-rich LiF and Li3N, contributing to a uniform Li deposition. Besides, the severe interface side reactions between LCO cathode and electrolyte can be retarded with an in situ formed protective layer. Correspondingly, Li||Li symmetrical cells achieve highly reversible Li plating/stripping over 1000h. The LCO||Li full cell can maintain 72.5% capacity after 1500 cycles with a decay rate of only 0.018% per cycle at a high charging voltage of 4.45V. Moreover, the well-designed eutectogel electrolyte can even enable the stable operation of LCO at an extremely high cutoff voltage of 4.6V. This work introduces a promising avenue for the advancement of eutectogel electrolytes, the nonflammable nature and well-regulated interphase significantly push forward the future application of lithium metal batteries and high-voltage utilization of LCO cathode.

In Situ Formed Robust Solid Electrolyte Interphase with Organic-Inorganic Hybrid Layer for Stable Zn Metal Anode.

Stabilizing the Zn anode/electrolyte interface is critical for advancing aqueous zinc ion storage technologies. Addressing this challenge helps minimize parasitic reactions and controls the formation of Zn dendrites, which is fundamental to achieving highly reversible Zn electrochemistry. In this study, 2% by volume of dimethyl sulfoxide (DMSO) is introduced into the baseline zinc sulfate (ZS) electrolyte, which acts as an efficient regulator to form a robust solid-electrolyte interphase (SEI) on the Zn anode. This innovative approach enables uniform Zn deposition and does not substantially modify the Zn2+ solvation structure. The Zn||Zn symmetric cell exhibits an extended cycle life of nearly one calendar year (>8500h) at a current density of 0.5mA cm-2 and an areal capacity of 0.5 mAh cm-2. Impressive full cell performance can be achieved. Specifically, the Zn||VS2 full cell achieves an areal capacity of 1.7 mAh cm-2, with a superior negative-to-positive capacity ratio of 2.5, and an electrolyte-to-capacity ratio of 101.4µL mAh-1, displaying remarkable stability over 1000 cycles under a high mass loading of 11.0mg cm-2 without significant degradation. This innovative approach in electrolyte engineering provides a new perspective on in situ SEI design and furthers the understanding of Zn anode stabilization.

Non-Fluorinated Ethers to Mitigate Electrode Surface Reactivity in High-Voltage NCM811-Li Batteries.

Lithium (Li) metal batteries (LMBs) with nickel (Ni)-rich layered oxide cathodes exhibit twice the energy density of conventional Li-ion batteries. However, their lifespan is limited by severe side reactions caused by high electrode reactivity. Fluorinated solvent-based electrolytes can address this challenge, but they pose environmental and biological hazards. This work reports on the molecular engineering of fluorine (F)-free ethers to mitigate electrode surface reactivity in high-voltage Ni-rich LMBs. By merely extending the alkyl chains of traditional ethers, we effectively reduce the catalytic reactivity of the cathode towards the electrolyte at high voltages, which suppresses the oxidation decomposition of the electrolyte, microstructural defects and rock-salt phase formation in the cathode, and gas release issues. The high-voltage Ni-rich NCM811-Li battery delivers capacity retention of 80 % after 250 cycles with a high Coulombic efficiency of 99.85 %, even superior to that in carbonate electrolytes. Additionally, this strategy facilitates passivation of the Li anode by forming a robust solid-electrolyte interphase, boosting the Li reversibility to 99.11 % with a cycling life of 350 cycles, which outperforms conventional F-free ether electrolytes. Consequently, the lifespan of practical LMBs has been prolonged by over 100 % and 500 % compared to those in conventional carbonate- and ether-based electrolytes, respectively.

Design and Mechanism Study of High-Safety and Long-Life Electrolyte for High-Energy-Density Lithium-Ion Batteries.

Although nonflammable electrolytes are beneficial for battery safety, they often adversely affect the electrochemical performance of lithium-ion batteries due to their poor compatibility with electrodes. Herein, we design a nonflammable electrolyte consisting of cyclic carbonate and 2,2-difluoroethyl acetate (DFEA) solvents paired with several surface-film-forming additives, significantly improving the safety and cycling performance of NMC811||SiOx/graphite pouch cells. The DFEA solvent exhibits not only good flame retardancy but also lower lowest unoccupied molecular orbital (LUMO) energy, promoting the formation of a robust inorganic-rich and gradient-architecture hybrid interface between the SiOx/graphite anode and electrolyte. The double insurance of good flame retardancy of the DFEA solvent and decreased exothermic effects of both bulk electrolyte and DFEA-derived solid electrolyte interphase (SEI) can ensure the high safety of the pouch cell. Moreover, the highly robust SEI can prevent the excessive reduction decomposition of the electrolyte and alleviate the structural decay of the anode, which can restrain the formation of lithium deposition on the anode surface and further suppress the structural decay of NMC materials. This contributes to the unprecedented cycling performance of the NMC811||SiOx/graphite pouch cells with a capacity retention of 80% after 1000 cycles at a 0.33C rate.

Unravelling solvation structure and interfacial mechanism of pyrrolidinium-based ionic liquid electrolytes in potassium-ion batteries

Ionic liquid-based electrolytes (ILEs) show great potential in mitigating the dissolution of organic electrode materials as well as manipulating the interfacial electrochemistry for long lifespan of potassium-ion batteries (PIBs). Herein, KFSI/Pyr13FSI ILEs with varying K+ and Pyr13+ ratios were designed to match a novel organic K-storage anode of p-toluic acid/CMK3 (PTA/CMK3). These ILEs exhibited facilely manipulated solvation structures, resulting into excellent compatibility with K-metal as well as promotion of the generation of robust solid-electrolyte interphase (SEI) for stable K-storage. As a result, the optimized PTA/CMK3||KFSI/Pyr13FSI K-storage system delivered a reversible capacity of 190 mAh/g(composites) alongside high coulomb efficiency of 99.7 % at a current density of 200 mA/g for 600 cycles. This work provides a fresh insight on rational design of ILEs-based advanced PIBs with high energy density and safety.

Constructing an Al3+/Zn2+-Based Solid Electrolyte Interphase to Enable Extraordinarily Stable Al3+-Based Electrochromic Devices.

The interface between the electrochromic (EC) electrode and ionic conductor is crucial for high-performance and extraordinarily stable EC devices (ECDs). Herein, the effect of the ALD-AZO interfacial layer on the performance of the WO3 thin film was examined, revealing that an introduction of the ALD-AZO interfacial layer to the Al3+-based complementary ECDs can lead to improved EC performance and stability, such as an extraordinary cyclability of more than 20,000 cycles, an outstanding coloration efficiency of 109.69 cm2 C-1, and a maximum transmittance modulation of 63.44%@633 nm. The probable explanation is that the introduced ALD-AZO interfacial layer can effectively regulate the band gap of WO3, promote the electron transport process, and induce the formation of a robust solid electrolyte interphase to protect the electrode during cycling. These findings offer valuable insights for enhancing the EC performance of the EC thin films and new space for the construction of advanced multivalent Al3+-based ECDs.

Lignin‐derived hard carbon anode with a robust solid electrolyte interphase for boosted sodium storage performance

AbstractHard carbon is regarded as a promising anode candidate for sodium‐ion batteries due to its low cost, relatively low working voltage, and satisfactory specific capacity. However, it still remains a challenge to obtain a high‐performance hard carbon anode from cost‐effective carbon sources. In addition, the solid electrolyte interphase (SEI) is subjected to continuous rupture during battery cycling, leading to fast capacity decay. Herein, a lignin‐based hard carbon with robust SEI is developed to address these issues, effectively killing two birds with one stone. An innovative gas‐phase removal‐assisted aqueous washing strategy is developed to remove excessive sodium in the precursor to upcycle industrial lignin into high‐value hard carbon, which demonstrated an ultrahigh sodium storage capacity of 359 mAh g−1. It is found that the residual sodium components from lignin on hard carbon act as active sites that controllably regulate the composition and morphology of SEI and guide homogeneous SEI growth by a near‐shore aggregation mechanism to form thin, dense, and organic‐rich SEI. Benefiting from these merits, the as‐developed SEI shows fast Na+ transfer at the interphases and enhanced structural stability, thus preventing SEI rupture and reformation, and ultimately leading to a comprehensive improvement in sodium storage performance.

Molecular crowding electrolytes for stabilizing Zn metal anode in rechargeable aqueous batteries

A solid electrolyte interphase (SEI) with a robust mechanical property and a high ionic conductivity is imperative for high-performance zinc metal batteries. However, it is difficult to form such a SEI directly from an electrolyte. In this work, a molecular crowding effect is based on the introduction of Zn(OTF)2 and Zn(ClO4)2 to 2 mol/L ZnSO4 electrolytes. Simulations and experiments indicate that the Zn(OTF)2 and Zn(ClO4)2 not only create a molecularly crowded electrolyte environment to promote the interaction of Zn2+and OTF−, but also participate in the reduction to construct a robust and high ionic-conductive SEI, thus promoting metal zinc deposition to the (002) crystal surface. With this molecular crowding electrolyte, a high current density of 1 mA/cm2 can be obtained by assembling symmetric batteries with Zn as the anode for over 1000 h. And in a temperature environment of −10 °C, a current density of 1 mA/cm2 can be obtained by assembling symmetric batteries with Zn for over 200 h. Zn//Bi2S3/VS4@C cells achieve a CE rate of up to 99.81% over 1000 cycles. Hence, the utilization of a molecular crowding electrolyte is deemed a highly effective approach to fabricating a sophisticated SEI for a zinc anode.

Revitalization of Diluent Amide-Based Electrolyte for Building High-Voltage Lithium-Metal Batteries.

Hitherto, highly concentrated electrolyte is the overarching strategy for revitalizing the usage of amide - in lithium-metal batteries (LMBs), which simultaneously mitigates the reactivity of amide toward Li and regulates uniform Li deposition via forming anion-solvated coordinate structure. However, it is undeniable that this would bring the cost burden for practical electrolyte preparation, which stimulates further electrolyte design toward tailoring anion-abundant Li+ solvation structure in stable amide electrolytes under a low salt content. Herein, a distinct method is conceived to design anions-enriched Li+ solvation structure in dilute amide-electrolyte (1m Li-salt concentration) with the aid of integrating perfluoropolyethers (PFPE-MC) with anion-solvating ability and B/F-involved additives. The optimized electrolyte based on N,N-Dimethyltrifluoroacetamide (FDMAC) exhibits outstanding compatibility with Li and NCM622 cathode, facilitates uniform Li deposition along with robust solid electrolyte interphase (SEI) formation. Accordingly, both the lab-level LMB coin cell and practical pouch cell based on this dilute FDMAC electrolyte deliver remarkable performances with improved capacity and cyclability. This work pioneers the feasibility of diluted amide as electrolyte in LMB, and provides an innovativestrategy for highly stable Li deposition via manipulating solvation structure within diluent electrolyte, impelling the electrolyte engineering development for practical high-energy LMBs.

Stable operation of highly loaded pure Si-Fe anode under ambient pressure via carboxy silane-directed robust solid electrolyte interphase

Incorporation of higher content Si anode material beyond 5 wt% to Li-ion batteries (LIBs) is challenging, owing to large volume change, swelling, and solid electrolyte interphase (SEI) instability issues. Herein, a strategy of diacetoxydimethylsilane (DAMS) additive-directed SEI stabilization is proposed for a stable operation of Si-0.33FeSi2 (named as Si-Fe) anode without graphite, which provides siloxane inorganics and organics enrichment that compensate insufficient passivation of fluoroethylene carbonate (FEC) additive and reduce a dependence on FEC. Unprecedented stable cycling performance of highly loaded (3.5 mA h cm−2) pure Si-Fe anode is achieved with 2 wt% DAMS combined with 9 wt% FEC additives under ambient pressure, yielding high capacity 1270 mA h g−1 at 0.5 C and significantly improved capacity retention of 81% after 100 cycles, whereas short circuit and rapid capacity fade occur with FEC only additive. DAMS-directed robust SEI layer dramatically suppresses swelling and particles crossover through separator, and therefore prevents short circuit, demonstrating a possible operation of pure Si or Si-dominant anodes in the next-generation high-energy-density and safe LIBs.