Solid Electrolyte Interface Layer Research Articles

In Situ Plasma Polymerization of Self-Stabilized Polythiophene Enables Dendrite-Free Lithium Metal Anodes with Ultra-Long Cycle Life.

Constructing a flexible and chemically stable multifunctional layer for the lithium (Li) metal anodes is a highly effective approach to improve the uneven deposition of Li+ and suppress the dendrite growth. Herein, an organic protecting layer of polythiophene is in situ polymerized on the Li metal via plasma polymerization. Compared with the chemically polymerized thiophene (C-PTh), the plasma polymerized thiophene layer (P-PTh), with a higher Young's modulus of 8.1GPa, shows strong structural stability due to the chemical binding of the polythiophene and Li. Moreover, the nucleophilic C─S bond of polythiophene facilitates the decomposition of Li salts in the electrolytes, promoting the formation of LiF-rich solid electrolyte interface (SEI) layers. The synergetic effect of the rigid LiF as well as the flexible PTh-Li can effectively regulate the uniform Li deposition and suppress the growth of Li dendrites during the repeated stripping-plating, enabling the Li anodes with long-cycling lifespan over 8000h (1mAcm-2, 1 mAhcm-2) and 2500h (10mAcm-2, 10 mAhcm-2). Since the plasma polymerization is facile (5-20min) and environmentally friendly (solvent-free), this work offers a novel and promising strategy for the construction of the forthcoming generation of high-energy-density batteries.

Stabilizing poly(vinylidene fluoride) solid-state electrolytes/lithium metal interface by constructing an ultrathin interface layer to inhibit the electron transfer

Residual N, N-dimethylformamide (DMF) enhances the conductivity of poly(vinylidene fluoride) (PVDF) solid-state polymer electrolytes (SPEs), but adversely impacts the SPEs/Li interface through electron transfer between DMF and Li. Herein, we developed a novel LiOH and LiNH2 (LON) artificial solid electrolyte interface (SEI) layer with limited electronic conductivity to block such electron transfer. Unlike conventional SEI, which are unsuitable for integration with SPEs since their high thickness (1–30 μm) results in high interfacial resistance, the LON layer is ultrathin (∼30 nm), and more importantly, it facilitates the separation of Li ions from Li-DMF bound ions during Li plating, contributing to a notable reduction in interfacial impedance. As a result, the LON protected Li (Li@LON)-based symmetrical cell exhibits an ultra-long cycle life of 2100 h and survives even under 0.6 mAh cm−2 at 25 °C, in stark contrast to the Bare Li-based symmetrical cell, which only maintains stable cycles for 806 h at 0.2 mAh cm−2. Furthermore, the Li@LON//LiNi0.8Co0.1Mn0.1O2 (NCM811) cell stably cycles over 3000 times at 0.5 C and 25 °C, significantly outperforming the Li//NCM811 cell with 880 times. This work paves a novel strategy for stabilizing SPEs-Li interface by constructing an ultrathin artificial SEI with low electronic conductivity.

BF4- Tailoring Solvation Chemistry of Ether-Based Electrolytes to Construct Stable Electrode/Electrolyte Interfaces for Sodium-Ion Full Batteries.

The ether-based electrolytes show excellent performance on anodes in sodium-ion batteries (SIBs), but they still show poor compatibility with the cathodes. Here, ether electrolytes with NaBF4 as the main salt or additive were applied in NFM//HC full cells and showed enhanced performance than the electrolyte with NaPF6. Then, BF4- was found to have a stronger interaction with Na+, which could reduce the solvation of Na+ with the solvent, thus inducing the formation of the cathode electrolyte interface (CEI) and solid electrolyte interface (SEI) layers rich in inorganic species. Moreover, the morphology, structure, composition, and solubility of CEI and SEI were explored, concluding that NaBF4 could induce more stable CEI and SEI layers rich in B-containing species and inorganics. This work proposes using NaBF4 as the main salt or additive to improve the performance of ether electrolytes in NFM//HC full cells, which provides a strategy to improve the compatibility of ether-based electrolytes and cathodes.

Artificial Hydrophilic Organic and Dendrite-Suppressed Inorganic Hybrid Solid Electrolyte Interface Layer for Highly Stable Zinc Anodes.

Aqueous zinc-ion batteries (AZIBs) have gained significant attentions for their inherent safety and cost-effectiveness. However, challenges, such as dendrite growth and anodic corrosion at the Zn anode, hinder their commercial viability. In this paper, an organic-inorganic coating layer (Nafion-TiO2) was introduced to protect the Zn anode and electrolyte interface. Briefly, Nafion effectively shields against the corrosion from water molecules through the hydrophobic wall of -CF3 and guided zinc deposition from the -SO3 functional group, while TiO2 particles with a higher Young's modulus (151 GPa vs 120 GPa from Zn metal) suppress the zinc dendrite formation. As a result, with the protection of Nafion-TiO2, the symmetrical Zn∥Zn battery shows an improved cycle life of 1,750 h at 0.5 mA cm-2, and the full cell based on Zn∥MnO2 shows a long cycle life over 1,500 cycles at 1 A g-1. Our research offers a novel approach for protecting zinc metal anodes, potentially applicable to other metal anodes such as those in lithium and sodium batteries.

Regenerated Graphite Electrodes with Reconstructed Solid Electrolyte Interface and Enclosed Active Lithium Toward >100% Initial Coulombic Efficiency.

Solid electrolyte interface (SEI) is arguably the most important concern in graphite anodes, which determines their achievable Coulombic efficiency (CE) and cycling stability. In spent graphite anodes, there are already-formed (yet loose and/or broken) SEIs and some residual active lithium, which, if can be inherited in the regenerated electrodes, are highly desired to compensate for the lithium loss due to SEI formation. However, current graphite regenerated approaches easily destroy the thin SEIs and residue active lithium, making their reuse impossible. Herein, this work reports a fast-heating strategy (e.g., 1900 K for ≈150ms) to upcycle degraded graphite via instantly converting the loose original SEI layer (≈100nm thick) to a compact and mostly inorganic one (≈10-30nm thick with a 26X higher Young's Modulus) and still retaining the activity of residual lithium. Thanks to the robust SEI and enclosed active lithium, the regenerated graphite exhibited 104.7% initial CE for half-cell and gifted the full cells with LiFePO4 significantly improved initial CE (98.8%versus 83.2%) and energy density (309.4versus 281.4Wh kg-1), as compared with commercial graphite. The as-proposed upcycling strategy turns the "waste" graphite into high-value prelithiated ones, along with significant economic and environmental benefits.

Thermal Structural Behavior of ElectrochemicallyLithiated Graphite (LixC6) Anodes in Li‐ion Batteries

AbstractA full series of variously lithiated graphite anodes material LixC6 (0<x<1) corresponding to a different state‐of‐charge (SOC) between 0 % and 100 % was collected from 18650‐type cylinder Li‐ion batteries, and the thermal structural behavior of these electrodes was mapped using ex situ high‐resolution X‐ray and neutron diffraction. Their structural behavior was analyzed over a broad temperature range. At high temperatures, a non‐reversible decomposition of the lithiated graphite anodes takes place, accompanied by a loss of intercalated lithium ions, forming novel phases such as LiF and Li2O strongly coupled to the degradation of the solid electrolyte interface (SEI). Complementary calorimetric measurements showed the strongly exothermic chemical reactions during the decomposition matching well to the collected diffraction data. Post mortem analysis applying scanning electron microscopy revealed various morphological features supplementing the treatment of battery anodes and highlighted the importance of the SEI layer during the cycling of the cell and its thermal degradation.

Facilitating prelithiation of silicon carbon anode by localized high‐concentration electrolyte for high‐rate and long‐cycle lithium storage

AbstractThe commercialization of silicon‐based anodes is affected by their low initial Coulombic efficiency (ICE) and capacity decay, which are attributed to the formation of an unstable solid electrolyte interface (SEI) layer. Herein, a feasible and cost‐effective prelithiation method under a localized high‐concentration electrolyte system (LHCE) for the silicon–silica/graphite (Si–SiO2/C@G) anode is designed for stabilizing the SEI layer and enhancing the ICE. The thin SiO2/C layers with –NH2 groups covered on nano‐Si surfaces are demonstrated to be beneficial to the prelithiation process by density functional theory calculations and electrochemical performance. The SEI formed under LHCE is proven to be rich in ionic conductivity, inorganic substances, and flexible organic products. Thus, faster Li+ transportation across the SEI further enhances the prelithiation effect and the rate performance of Si–SiO2/C@G anodes. LHCE also leads to uniform decomposition and high stability of the SEI with abundant organic components. As a result, the prepared anode shows a high reversible specific capacity of 937.5 mAh g−1 after 400 cycles at a current density of 1 C. NCM 811‖Li‐SSG‐LHCE full cell achieves a high‐capacity retention of 126.15 mAh g−1 at 1 C over 750 cycles with 84.82% ICE, indicating the great value of this strategy for Si‐based anodes in large‐scale applications.

Electrochemical Hydrophobic Tri‐layer Interface Rendered Mechanically Graded Solid Electrolyte Interface for Stable Zinc Metal Anode

AbstractThe aqueous zinc‐ion battery is promising as grid scale energy storage device, but hindered by the instable electrode/electrolyte interface. Herein, we report the lean‐water ionic liquid electrolyte for aqueous zinc metal batteries. The lean‐water ionic liquid electrolyte creates the hydrophobic tri‐layer interface assembled by first two layers of hydrophobic OTF− and EMIM+ and third layer of loosely attached water, beyond the classical Gouy–Chapman–Stern theory based electrochemical double layer. By taking advantage of the hydrophobic tri‐layer interface, the lean‐water ionic liquid electrolyte enables a wide electrochemical working window (2.93 V) with relatively high zinc ion conductivity (17.3 mS/cm). Furthermore, the anion crowding interface facilitates the OTF− decomposition chemistry to create the mechanically graded solid electrolyte interface layer to simultaneously suppress the dendrite formation and maintain the mechanical stability. In this way, the lean‐water based ionic liquid electrolyte realizes the ultralong cyclability of over 10000 cycles at 20 A/g and at practical condition of N/P ratio of 1.5, the cumulated areal capacity reach 1.8 Ah/cm2, which outperforms the state‐of‐the‐art zinc metal battery performance. Our work highlights the importance of the stable electrode/electrolyte interface stability, which would be practical for building high energy grid scale zinc‐ion battery.

Electrochemical Hydrophobic Tri-layer Interface Rendered Mechanically Graded Solid Electrolyte Interface for Stable Zinc Metal Anode.

The aqueous zinc-ion battery is promising as grid scale energy storage device, but hindered by the instable electrode/electrolyte interface. Herein, we report the lean-water ionic liquid electrolyte for aqueous zinc metal batteries. The lean-water ionic liquid electrolyte creates the hydrophobic tri-layer interface assembled by first two layers of hydrophobic OTF- and EMIM+ and third layer of loosely attached water, beyond the classical Gouy-Chapman-Stern theory based electrochemical double layer. By taking advantage of the hydrophobic tri-layer interface, the lean-water ionic liquid electrolyte enables a wide electrochemical working window (2.93 V) with relatively high zinc ion conductivity (17.3 mS/cm). Furthermore, the anion crowding interface facilitates the OTF- decomposition chemistry to create the mechanically graded solid electrolyte interface layer to simultaneously suppress the dendrite formation and maintain the mechanical stability. In this way, the lean-water based ionic liquid electrolyte realizes the ultralong cyclability of over 10000 cycles at 20 A/g and at practical condition of N/P ratio of 1.5, the cumulated areal capacity reach 1.8 Ah/cm2 , which outperforms the state-of-the-art zinc metal battery performance. Our work highlights the importance of the stable electrode/electrolyte interface stability, which would be practical for building high energy grid scale zinc-ion battery.

A high-efficient stable surface-prelithiated Li1.2Ni0.13Co0.13Mn0.54O2 cathode enabled by sacrificial lithium nitrides for high-energy-density lithium-ion batteries

Lithium-rich cathode materials with superior practical specific capacity over 250 mAh g−1 are considered as one of the resolutions for high-energy-density lithium-ion batteries, while the intrinsic capacity loss caused by solid electrolyte interface (SEI) formation on the anode impedes the increase of energy density. To address this issue, we propose a composite cathode prelithiation strategy including a carbon-incorporated lithium phosphorus oxynitride (LiCPON) layer and a sacrificial Li3N (Sac. Li3N) layer, which can not only compensate for the capacity loss effectively and controllably with a high lithium utilization rate over 85% but also provide outstanding atmosphere stability with an 80.2% lithium utilization rate after exposed in dry air for 8 hours. The energy densities achieve 489.5 Wh kg−1 and 497.3 Wh kg−1 initially after cathode prelithiation in full cells paired with Si/C and SiOx/C anodes, corresponding to a 11.9% and 11.6% increase, respectively. The energy densities still remain 318.7 Wh kg−1 and 319.7 Wh kg−1 after 50 cycles with an increase of 13.7% and 11.7%, respectively. The cathode electrolyte interface (CEI) and SEI layers are mutually optimized and the electrolyte adsorption and degradation are suppressed after cathode prelithiation. Our work has demonstrated that such a composite cathode prelithiation strategy provides the possibility for large-scale industrial production, transportation, and conservation of prelithiated lithium-rich cathodes to achieve high-energy-density lithium-ion batteries.

Tea‐Derived Sustainable Materials

AbstractThe practical application of hard carbon in sodium‐ion batteries is limited by insufficient reversible capacity and low initial Coulombic efficiency (ICE), which are caused by the lack of active sites and unstable electrode/electrolyte interface. Herein, a biomass‐derived hard carbon material based on tea stems is proposed, which exhibits an ultrahigh ICE of 90.8%. This remarkable ICE is attributed to the presence of an inorganic‐rich, thin, and robust solid electrolyte interface (SEI) layer. Furthermore, the material demonstrates excellent cycling stability, showing a capacity retention of 99.5% after 500 cycles at 280 mA g−1. Additionally, when it works as the anode material in a sodium‐ion full cell without presodiation, it reaches a high energy density of 212 Wh kg−1 and a superior stability, e.g., retaining 93.1 mAh g−1 after 1000 cycles at 1 A g−1 with a capacity retention of 91.3%. The sodium storage capacity of this material is primarily attributed to a combined adsorption‐intercalation/filling effect as confirmed by in situ XRD and ex situ Raman analyses. These findings make this biomass‐derived hard carbon material a promising candidate for commercial application of sodium‐ion batteries, achieving high performance at low cost.

Composition Analysis of the Solid Electrolyte Interface of NaK Anodes in Na-Ion Batteries.

Sodium-ion batteries have emerged as a promising alternative to Li-ion batteries due to the abundance of sodium. However, anodes in Na-ion batteries face challenges such as dendrite formation and an unstable solid electrolyte interface layer. To address these challenges, NaK liquid metal alloy anodes have been proposed as an alternative because they do not form dendrites. In our study, we demonstrate that the NaK alloy anode interacts with the commonly used ethylene carbonate and dimethyl carbonate electrolyte, leading to a continuously growing unstable SEI layer, evidenced by cycling failures under 100 cycles and an increasing charge transfer resistance in electrochemical impedance spectroscopy studies. In situ surface-enhanced Raman spectroscopy and X-ray photoelectron spectroscopy reveal that over the course of cycling the surface of the NaK anode becomes increasingly sodium-rich. After 30 cycles, XPS analysis detects only trace amounts of potassium on the NaK anode surface. When the electrolyte is analyzed postcycling using inductively coupled plasma optical emission spectroscopy, there is a noticeable increase in potassium levels, suggesting that potassium metal dissolves into the electrolyte. The introduction of a 10 wt % fluoroethylene carbonate additive can mitigate this problem to some extent, enabling an enhanced cycling performance of up to 800 cycles at 1C. Nevertheless, the dissolution of K metal is still evident in the XPS results, albeit to a lesser degree. These discoveries provide valuable insights for designing a more robust SEI layer for the NaK anode.

Bottom-preferred stripping mechanism towards quantified inactive metallic Zn0-dominant zinc loss in rechargeable zinc metal battery

Electrically isolated metallic Zn (Zn0) and electrochemically side reaction (ECSR), causes irreversible anode capacity loss and limited cycle life in zinc metal battery. However, the quantitative distinguishment between inactive metallic Zn0 and ECSR, their formation mechanism and correlation with anode cycling reversibility have never been disclosed, limiting further anode modification design. Here, we develop an acid-assisted continuous titration-collection-gas chromatography technique (AAC-TCGC) that accurately quantify the amount of inactive Zn0 and ECSR in anode, and discover that inactive Zn0 accounts for the majority of Zn loss, rather than the commonly-assumed electrochemically side reaction-derived ECSR-dominant Zn anode capacity loss. Detailed component of SEI (Solid Electrolyte Interface Layer) compound is also characterized, illustrating a solvent-derived zinc oxide/hydroxide-dominant SEI that facilitates vertical/inclined thin-plate Zn deposition, but salt-derived ZnF2-dominant SEI that favors horizontal platelet-shaped Zn(002) deposition. Simulation results reveal a new electric resistance-derived, bottom-preferred Zn stripping mechanism that leads to abundant inactive Zn0 formation in vertical thin-plate Zn deposition structure, but few inactive Zn0 in dumpy platelet-shaped Zn structure. Our study provides new theories and strategies on the distinguishment, formation mechanism and structure-performance relationship of inactive Zn, important for building more efficient Zn metal battery.

Modification of solid electrolyte interface layer between PVDF-based electrolyte and lithium anode

Poly(vinylidene fluoride) (PVDF)-based polymer electrolytes (PEs) with good electrochemical performance and processability as well as low-cost advantage, have great potential applications in solid-state lithium (Li) metal batteries (SSLMBs). PVDF-based PEs are generally produced by employing a solution-casting approach with N,N-dimethylformamide (DMF) as the solvent, accompanied by the formation of [DMF-Li+] complex, which facilitates the Li-ion transport. However, the residual DMF can react continuously with lithium (Li) metal, thereby deteriorating the interface layer in the middle of the PVDF-based PEs and Li anodes. Herein, we introduce propylene carbonate (PC) into the PVDF-based PEs to regulate the solvation structure and stabilize the interface layer between the PEs and Li anodes. PC accelerates the dissociation of lithium oxalyldifluoroborate (LiODFB). Consequently, “lithium propylene dicarbonate (LPDC)‒B-O″ oligomer forms as the interfacial layer with high tenacity, homogeneity, and densification, which improves the interfacial contact and suppresses the continuous reaction between the residual DMF and Li anode. We further demonstrate that the PVDF-based PE prepared with DMF-PC mix-solvents shows improved room-temperature ionic conductivity (1.18 × 10−3 S/cm), enhanced stability against electrodes, and superior cycling performance in LiCoO2-based SSLMBs (maintaining 84 % of the initial discharge capacity after 300 cycles).

Weakly Solvating Few-Layer-Carbon Interface toward High Initial Coulombic Efficiency and Cyclability Hard Carbon Anodes.

The carbonaceous anodes in sodium ion batteries suffer from low initial Coulombic efficiency (ICE) and poor cyclability due to rampant solid electrolyte interface (SEI) growth. The concept of the weakly solvating electrolyte (WSE) has been popularized for SEI regulation on the anode by adjusting the cation solvation structure. Nevertheless, the effects on the solvation sheath from the electrode/electrolyte interface are ignored in most WSE applications. In this work, we extend the WSE from the bulk electrolyte to the electrolyte/carbon interface. By recycling asphalt wastes into sp2 C enriched few-layer carbon on hard carbon, a weakly solvating interface is fabricated with lower adsorption energy to electrolyte solvent molecules than a pristine anode (-0.89 vs -1.08 eV for Na/diglyme). Accordingly, more anionic groups are attracted into the solvent-weakened solvation sheath during sodiation (2.30 vs 1.96 coordination number for PF6-). The anion-mediated contact ion pairs facilitate a thin, inorganic-rich SEI layer with a homogeneous distribution, which confers a high ICE of 97.9% and a high capacity of 335.6 mA h g-1 at 1 C (89.5% retention, 1000 cycles). The full battery also manifests an energy density of 209 W h kg-1. This interfacial design is applicable in both ether- and ester-based electrolytes, which is promising in cost-effective modification for carbonaceous electrodes.

Novel design of high elastic solid polymer electrolyte for stable lithium metal batteries

Li metal anodes have high specific capacity and low electrode potential, and have always been considered as one of the most promising anode materials. However, the growth of Li dendrites, unstable solid electrolyte interface layer (SEI), severe side reactions at the Li/electrolyte interface, and infinite volume expansion of the Li anode seriously hinder the practical application of solid-state Li metal batteries (LMBs). Herein, we report a polyurethane elastomer (TPU) material with high elasticity and interfacial stability as a solid polymer electrolyte (SPE) for LMBs. The synergistic effects of its designed soft chain forging (PEO) and hard chain segments (IPDI) can enhance Li ion conductivity, elastic modulus and flexibility of the SPE to settle the challenges of the Li metal anodes. Moreover, Li2S, as a solid-state electrolyte additive, is able to effectively inhibit the occurrence of side reactions at the interface between Li metal and SPE, promote the decomposition of N(CF3SO2)2− and in-situ generation of LiF with low Li+ diffusion barrier and excellent electronic insulation, achieving rapid Li ion transport and uniform Li deposition. As a result, stable cycle of up to 1400 h has been achieved for a Li||TPU-Li2S||Li battery at 0.1 mA/cm2 at 50 ℃, accompanied with a stable cycling performance of 350 h at a higher current density of 0.5 mA/cm2. Finally, the LiFePO4||TPU-Li2S||Li full battery exhibits an excellent cycling performance with a capacity retention rate of 80 % after 500 cycles at 1C. This simple and low-cost strategy provides novel design thoughts for practical application of high-performance SPEs in stable and long-life LMBs.

Revolutionizing aqueous Zn-ion batteries: Precision control of H2O activity and Zn deposition through ammonium oxalate additive

The natural reactivity of Zn metal in aqueous environments leads to surface deterioration and uncontrolled dendrite growth, posing challenges in the advancement of Zn-ion batteries. In this research, we introduce an environmentally friendly and cost-effective electrolyte additive, ammonium oxalate (AO), to significantly extend the cycle life of Zn-ion batteries with minimal usage. Oxalate ions within AO actively participate in the solvation of hydrated Zn ions and attach to the Zn anode surface prior to H2O molecules, creating a robust solid-electrolyte interface (SEI) layer. This SEI layer serves a dual purpose: it inhibits further reactions with H2O and restricts the two-dimensional movement of Zn ions, promoting the preferential growth of the (002) crystal plane. Consequently, Zn||Zn cells exhibit an impressive lifespan surpassing 1800 h (at 1 mA cm−2, 1 mAh cm−2), and Zn||Cu cells experience a tenfold increase in cycling life. Moreover, Zn||MnO2 full cells, incorporating this low-cost and highly efficient inorganic additive, maintain an outstanding 80.84 % capacity retention after 1200 cycles at 1 A g−1. This breakthrough with AO offers a promising avenue for the practical implementation of Zn-ion batteries, emphasizing their cost-effectiveness and environmental sustainability.

Effective coating of polydopamine-mediated polyacrylamide on SiOx microparticles enables stable interface chemistry

Functional polymer coating is one of effective strategies to achieve high performance Si-based anodes for lithium-ion batteries (LIBs). Unfortunately, many functional polymers are incompatible with carbon layer which are important for electrical conductivity of Si-based composites, especially for carbon-coated SiOx microparticles (SiOC). Here, we present a polydopamine (PDA)-mediated strategy that enables a robust polyacrylamide (PAM) polymer to effectively couple with SiOC microparticles through the PDA bridge. As a robust barrier, the PDA-PAM coating effectively inhibits electrolyte corrosion while promoting the formation of a stable solid electrolyte interface layer. The resulting SiOC@PDA-PAM microparticles display enhanced cycling stability without sacrificing their rate performance. The pouch cell incorporated with 10 wt% SiOC@PDA-PAM in graphite anode has a superior capacity retention of 85.1% after 800 cycles and an improved storage performance due to the stable interfacial chemistry of SiOC@PDA-PAM. Considering the strong adhesion and easy functionalization of PDA for surface modification, this work spotlights the prospect of developing more functional polymer coating to extend the cycling life of Si-based anodes.

Suppressing Li dendrite by a guar gum natural polymer film for high‐performance lithium metal anodes

AbstractLithium dendrites pose a major hurdle for enhancing the energy density of lithium metal batteries, and the artificial solid electrolyte interface layer offers a potential solution. In this work, a cost‐effective and environmentally friendly guar gum film is applied to the artificial protective layer. The guar gum artificial solid electrolyte interface (SEI) layer formed naturally, enriched with OH and AOA groups, displayed exceptional electrochemical stability, and achieved an impressively high transference number of 0.88 for lithium‐ion movement. In symmetric cells, the Li@GG‐Cu anode displays remarkable cycling performance even during extended periods. This is evidenced by its ability to maintain a surface capacity of approximately 850 h (1 mA cm−2, 1 mAh cm−2). In addition, when utilizing a complete cell setup comprising a LiFPO4 cathode (weighing 1.5 mg cm−2) and anode coated with a guar gum film, the capacity retention of an impressive 96.2% showcases outstanding preservation of battery performance over time even after 700 cycles. This performance surpasses that of a lithium foil electrode (87.1%) and a copper anode with lithium deposition (0%). Our work exhibits a promising material for a novel configuration of artificial SEI, effectively stabilizing lithium metal anode.

Organic solid-electrolyte interface layers for Zn metal anodes.

Zinc ion batteries (ZIBs) have emerged as promising candidates for renewable energy storage owing to their affordability, safety, and sustainability. However, issues with Zn metal anodes, such as dendrite growth, hydrogen evolution reaction (HER), and corrosion, significantly hinder the practical application of ZIBs. To address these issues, organic solid electrolyte interface (SEI) layers have gained traction in the ZIB community as they can, for instance, help achieve uniform Zn plating/stripping and suppress side reactions. This article summarizes recent advances in organic artificial SEI layers for ZIB anodes, including their fabrication methods, electrochemical performance, and degradation suppression mechanisms.