High Interfacial Energy Research Articles

In situ Triggered Rich‐LiF/Mg Multifunctional Passivation Layer for Modifying the Anode Interface of All‐Solid‐State Lithium Metal Batteries

AbstractLithium (Li) is a promising anode material for all‐solid‐state Li metal batteries (ASSLMBs) due to its high energy density. However, the interface incompatibility of Li/solid electrolyte and uneven Li deposition induces the penetration of Li dendrites. Herein, a multifunctional rich‐LiF/Mg artificial solid electrolyte interphase (SEI) layer is constructed from a MgF2‐PVDF‐HFP film to passivate the Li anode and achieve effective inhibition of Li dendrites. Notably, the triggered LixMg alloys rivet the Li6PS5Cl (LPSCl) electrolyte and Li anode together well, producing satisfactory interface contact and reducing overpotential. The mechanism of LiF and LixMg alloys to enhance the stability of the Li/LPSCl interface is further elucidated by density functional theory (DFT). Moreover, the synergistic interaction of LiF with high interfacial energy and LixMg alloys with low diffusion barrier promotes uniform deposition of Li during plating/stripping and structural stability. Therefore, the modified Li‐symmetric cell exhibits ultra‐high critical current density (2.0 mA cm−2) and considerable cyclic stability (more than 1000 h at 0.5 mA cm−2). Remarkably, NCM//LPSCl//3% MgF2‐PVDF‐HFP@Li ASSLMBs exhibit considerable long‐term cycle stability (86.9% capacity retention after 100 cycles at 0.2 C). This work highlights the critical role of the intermediate passivating layer in mitigating side reactions and preventing Li penetration.

SnF2-Catalyzed Lithiophilic-Lithiophobic Gradient Interface for High-Rate PEO-Based All-Solid-State Batteries.

Polyethylene oxide (PEO)-based all-solid-state lithium metal batteries (ASSLMBs) are strongly hindered by the fast dendrite growth at the Li metal/electrolyte interface, especially under large rates. The above issue stems from the suboptimal interfacial chemistry and poor Li+ transport kinetics during cycling. Herein, a SnF2-catalyzed lithiophilic-lithiophobic gradient solid electrolyte interphase (SCG-SEI) of LixSny/LiF-Li2O is in situ formed. The superior ionic LiF-Li2O rich upper layer (17.1 nm) possesses high interfacial energy and fast Li+ diffusion channels, wherein lithiophilic LixSny alloy layer (8.4 nm) could highly reduce the nucleation overpotential with lower diffusion barrier and promote rapid electron transportation for reversible Li+ plating/stripping. Simultaneously, the insoluble SnF2-coordinated PEO promotes the rapid Li+ ion transport in the bulk phase. As a result, an over 46.7 and 3.5 times improvements for lifespan and critical current density of symmetrical cells are achieved, respectively. Furthermore, LiFePO4-based ASSLMBs deliver a recorded cycling performance at 5 C (over 1000 cycles with a capacity retention of 80.0 %). More importantly, impressive electrochemical performances and safety tests with LiNi0.8Mn0.1Co0.1O2 and pouch cell with LiFePO4, even under extreme conditions (i.e., 100 °C), are also demonstrated, reconfirmed the importance of lithiophilic-lithiophobic gradient interfacial chemistry in the design of high-rate ASSLMBs for safety applications.

SnF2‐Catalyzed Lithiophilic–Lithiophobic Gradient Interface for High‐Rate PEO‐Based All‐Solid‐State Batteries

AbstractPolyethylene oxide (PEO)‐based all‐solid‐state lithium metal batteries (ASSLMBs) are strongly hindered by the fast dendrite growth at the Li metal/electrolyte interface, especially under large rates. The above issue stems from the suboptimal interfacial chemistry and poor Li+ transport kinetics during cycling. Herein, a SnF2‐catalyzed lithiophilic‐lithiophobic gradient solid electrolyte interphase (SCG‐SEI) of LixSny/LiF‐Li2O is in situ formed. The superior ionic LiF‐Li2O rich upper layer (17.1 nm) possesses high interfacial energy and fast Li+ diffusion channels, wherein lithiophilic LixSny alloy layer (8.4 nm) could highly reduce the nucleation overpotential with lower diffusion barrier and promote rapid electron transportation for reversible Li+ plating/stripping. Simultaneously, the insoluble SnF2‐coordinated PEO promotes the rapid Li+ ion transport in the bulk phase. As a result, an over 46.7 and 3.5 times improvements for lifespan and critical current density of symmetrical cells are achieved, respectively. Furthermore, LiFePO4‐based ASSLMBs deliver a recorded cycling performance at 5 C (over 1000 cycles with a capacity retention of 80.0 %). More importantly, impressive electrochemical performances and safety tests with LiNi0.8Mn0.1Co0.1O2 and pouch cell with LiFePO4, even under extreme conditions (i.e., 100 °C), are also demonstrated, reconfirmed the importance of lithiophilic‐lithiophobic gradient interfacial chemistry in the design of high‐rate ASSLMBs for safety applications.

Synergy of γ′ phase, MC carbide and grain boundary phase on creep behavior for nickel-based superalloy K439B

The synergy of γ′ phase, MC carbide and grain boundary phase on 815 °C/379 MPa creep behavior for nickel-based superalloy K439B was investigated by adjusting the time and temperature of the first-stage aging treatment. Increasing aging time from 4 h to 6 h, the total creep life is reduced by 35.8% due to the increased bimodal γ′ phase size. The bimodal γ′ phase transforms into small unimodal γ′ phase when increasing aging temperature from 1000 °C to 1080 °C. In addition, the content of M23C6 carbide increases, and the total creep life is increased by about 1.3 times. Small-size γ′ phase with bimodal distribution redissolves into γ matrix during creep deformation. Dislocations pile up at the γ/γ′ interface, and partial dislocations enter into large-size γ′ phase, mainly forming isolated parallel stacking faults. By comparison, the crossed stacking faults within small unimodal γʹ phase form Lomer-Cottrell locks, APB coupled dislocation pairs shear into γʹ phase, and more granular M23C6 carbide precipitates at the grain boundary, which further decreases the minimum steady creep rate and improves the creep life. At the beginning of creep deformation, MC carbide prevents the movement of dislocations. MC carbide formed at grain boundaries can delay crack propagation to a certain extent. MC carbide debonds from γ matrix subsequently due to the dislocation accumulation and higher interface energy, which provides a pathway for crack initiation and propagation. Moreover, the fragmentation and degeneration inside MC carbide promote crack initiation.

Functional ternary salt construction enabling an in-situ Li3N/LiF-enriched interface for ultra-stable all-solid-state lithium metal batteries

Poly(ethylene oxide)-based polymer all-solid-state lithium metal batteries (ASSLBs) have received widespread attention due to their low cost, good process ability, and high energy density. Nevertheless, the growth of Li dendrites within polymer solid-state electrolytes damages the reversibility of Li anodes and still impedes their widespread application. One efficient strategy is to construct a superior solid electrolyte interface. Herein, a stable interface enriched with Li3N and LiF is in-situ formed between Li anode and a ternary salt electrolyte. This ternary salt electrolyte is innovatively designed by introducing lithium bis(trifluoromethane sulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and LiNO3 to poly(ethylene oxide) matrix. Surface characterization indicates that LiNO3 and LiFSI contribute to forming a Li3N-LiF-enriched interface and meanwhile LiTFSI ensures excellent conductivity. Theoretically, among various Li compound components, Li3N has high ionic conductivity, which is beneficial for reducing overpotential, while LiF has high interfacial energy which can enhance nucleation energy and suppress the formation of Li dendrites. The experimental results show that ASSLBs coupled with LiFePO4 cathode display extremely excellent cycle stability approximately 2200 cycles at 2 C, with a final and corresponding discharge specific capacity of 96.7 mA h g−1. Additionally, a schematic illustration of the working mechanism for the Li3N-LiF interface is proposed.

Bacterial nanocellulose as a simple and tailorable platform for controlled drug release

In this study we present a proof of concept of a simple and straightforward approach for the development of a Bacterial Nanocellulose drug delivery system (BNC-DDS), envisioning the local delivery of immunomodulatory drugs to prevent foreign body reaction (FBR). Inspired by the self-adhesion behavior of BNC upon drying, we proposed a BNC laminate entrapping commercial crystalline drugs (dexamethasone-DEX and GW2580) in a sandwich system. The stability of the bilayer BNC-DDS was evidenced by the high interfacial energy of the bilayer films, 150 ± 11 and 88 ± 7 J/m2 respectively for 2 mm- and 10-mm thick films, corresponding to an increase of 7.5 and 4.4-fold comparatively to commercial tissue adhesives. In vitro release experiments unveiled the tunability of the bilayer BNC-DDS by showing extended drug release when thicker BNC membranes were used (from 16 to 47 days and from 35 to 132 days, for the bilayer-BNC entrapping DEX and GW2580, respectively). Mathematical modeling of the release data pointed to a diffusion-driven mechanism with non-fickian behavior. Overall, the results have demonstrated the potential of this simple approach for developing BNC-drug depots for localized and sustained release of therapeutic agents over adjustable timeframes.

In Situ Visual Observation of Surface Energy-Controlled Heterogeneous Nucleation of Metal Nanocrystals.

Electrochemical growth of metal nanocrystals is pivotal for material synthesis, processing, and resource recovery. Understanding the heterogeneous interface between electrolyte and electrode is crucial for nanocrystal nucleation, but the influence of this interaction is still poorly understood. This study employs advanced in situ measurements to investigate the heterogeneous nucleation of metals on solid surfaces. By observing the copper nanocrystal electrodeposition, an interphase interaction-induced nucleation mechanism highly dependent on substrate surface energy is uncovered. It shows that a high-energy (HE) electrode tended to form a polycrystalline structure, while a low-energy (LE) electrode induced a monocrystalline structure. Raman and electrochemical characterizations confirmed that HE interface enhances the interphase interaction, reducing the nucleation barrier for the sturdy nanostructures. This leads to a 30.92-52.21% reduction in the crystal layer thickness and a 19.18-31.78% increase in the charge transfer capability, promoting the formation of a uniform and compact film. The structural compactness of the early nucleated crystals enhances the deposit stability for long-duration electrodeposition. This research not only inspires comprehension of physicochemical processes correlated with heterogeneous nucleation, but also paves a new avenue for high-quality synthesis and efficient recovery of metallic nanomaterials.

Statistical Copolymerization-Induced Self-Assembly.

Statistical copolymers have been extensively used in chemical industries and our daily lives, owing to their ease of synthesis and functionalization. However, self-assembly based on statistical copolymers has been haunted by high interfacial energy, poor stability, and low concentration. We proposed the statistical copolymerization-induced self-assembly (stat-PISA) as a general strategy for one-step preparing stable statistical copolymer assemblies with high solids content. The concept was demonstrated through a model dispersion polymerization system comprising a charged hydrophilic monomer and a core-forming monomer, producing spherical micelles via a spinodal decomposition mechanism with an interconnected network intermediate. The stat-PISA was tunable by varying the fraction of charged monomer, the polymer chain length, and the solids content. The statistical copolymer micelles were demonstrated to be a potential Pickering emulsifier with superior stabilizing performances compared to their block copolymer counterparts. The general applicability of stat-PISA was demonstrated by preparing statistical copolymer assemblies with varying surface charges and chemical compositions. Particularly, this strategy is feasible for conventional free radical polymerization, promising for industrial scale-up.

Atomic sawtooth-like metal films for vdW-layered single-crystal growth

Atomic sawtooth surfaces have emerged as a versatile platform for growth of single-crystal van der Waals layered materials. However, the mechanism governing the formation of single-crystal atomic sawtooth metal (copper or gold) films on hard substrates (tungsten or molybdenum) remains a puzzle. In this study, we aim to elucidate the formation mechanism of atomic sawtooth metal films during melting–solidification process. Utilizing molecular dynamics, we unveil that the solidification of the liquid copper initiates at a high-index tungsten facet with higher interfacial energy. Subsequent tungsten facets follow energetically favourable pathways of forming single-crystal atomic sawtooth copper film during the solidification process near melting temperature. Formation of atomic sawtooth copper film is guaranteed with a film thickness exceeding the grain size of polycrystalline tungsten substrate. We further demonstrate the successful growth of centimeter-scale single-crystal monolayer hexagonal boron nitride films on atomic sawtooth copper films and explore their potential as efficient oxygen barrier.

Study on mechanical properties and molecular simulation of nano‐SiO2‐modified hybrid fiber reinforced polymer bar under the dry and alkaline environment

AbstractFiber reinforced polymer (FRP) bars have received extensive promotion and application in the structural engineering. However, due to the limitations inherent in using single material, FRP reinforced concrete structures often encounter issues, such as brittle failure and inadequate energy dissipation, particularly in complex natural environments and under various loading conditions. In this study, the preparation of nano‐SiO2‐modified carbon/basalt hybrid FRP bars was carried out using the pultrusion‐winding process and ultrasonic treatment. The objective was to investigate the influence of the fiber volume ratio and mass fraction of nano‐SiO2 on the mechanical properties of FRP bars under drying and alkaline conditions. Molecular dynamics simulations were performed to construct interface models between fibers and epoxy resin in order to elucidate the toughening mechanism of nano‐SiO2 and the degradation mechanism in alkaline conditions. The research results show that elevating the substitution rate of carbon fibers and incorporating nano‐SiO2 doping bring about alterations in the brittle fracture characteristics of BFRP bars and enhance the post‐yield performance and interlaminar shear properties of hybrid FRP bars, concurrently mitigating the degradation of mechanical properties induced by exposure to alkaline solutions. MD simulations indicate that the addition of nano‐SiO2 improves the binding rate of hydrogen bonds between BF and epoxy resin, resulting in a higher interfacial energy between BF/epoxy resin compared to CF/epoxy resin. Moreover, nano‐SiO2 effectively mitigates the impact of alkaline solutions on the formation of interfacial hydrogen bonds. The findings of this study serve as a valuable reference for the design and application of FRP reinforced concrete structures.Highlights Nano‐SiO2 modified B/CFRP bars made via extrusion‐winding & ultrasonic treatment. Improved mechanical properties and plastic deformation in Nano‐SiO2 modified B/C FRP bars. Nano‐SiO2 inhibits B/CFRP bars degradation in alkaline solution. Nano‐SiO2 bind more at BF/epoxy than CF/epoxy interface. Nano‐SiO2 reduces alkaline solution effect on interfacial H‐bonding.

Stable Oxyhalide-Nitride Fast Ionic Conductors for All-Solid-State Li Metal Batteries.

Rechargeable all-solid-state lithium metal batteries (ASSLMBs) utilizing inorganic solid-state electrolytes (SSEs) are promising for electric vehicles and large-scale grid energy storage. However, the Li dendrite growth in SSEs still constrains the practical utility of ASSLMBs. To achieve a high dendrite-suppression capability, SSEs must be chemically stable with Li, possess fast Li transfer kinetics, and exhibit high interface energy. Herein, a class of low-cost, eco-friendly, and sustainable oxyhalide-nitride solid electrolytes (ONSEs), denoted as LixNyIz-qLiOH (where x = 3y + z, 0 ≤ q ≤ 0.75), is designed to fulfill all the requirements. As-prepared ONSEs demonstrate chemically stable against Li and high interface energy (>43.08 meV Å-2), effectively restraining Li dendrite growth and the self-degradation at electrode interfaces. Furthermore, improved thermodynamic oxidation stability of ONSEs (>3V vs Li+/Li, 0.45V for pure Li3N), arising from the increased ionicity of Li─N bonds, contributes to the stability in ASSLMBs. As a proof-of-concept, the optimized ONSEs possess high ionic conductivity of 0.52 mS cm-1 and achieve long-term cycling of Li||Li symmetric cell for over 500h. When coupled with the Li3InCl6 SSE for high-voltage cathodes, the bilayer oxyhalide-nitride/Li3InCl6 electrolyte imparts 90% capacity retention over 500 cycles for Li||1 mAh cm-2 LiCoO2 cells.

Improving long-term thermal stability in twin-roll cast Al-Mg-Si-Cu alloys by optimizing Mg/Si ratios

Achieving high thermal stability in the 6xxx series alloys remains a challenging task, which limits their engineering application. Herein, Al-Mg-Si-Cu alloys with various Mg/Si ratios (0.5, 1, 2, and 4) were fabricated by twin-roll casting (TRC), and the microstructure evolution and mechanical properties during long-term thermal exposure of 150 °C/1000 h were studied. The results disclosed that alloys with a high Mg/Si ratio exhibited better thermal stability. The alloys with the Mg/Si ratio of 2 (Mg/Si∼2) achieved a stable high yield strength of ∼330 MPa and meanwhile maintained a satisfactory fracture elongation (> 10 %) throughout the thermal exposure process. This excellent thermal stability can be attributed to the microstructure consisting of high-density L phases and fine α-AlFeSi phases, which was related to the optimized Mg/Si ratio. Specifically, L phases were dominated in peak-aged Mg/Si∼2 alloys, while the counterparts in alloys with the Mg/Si ratio of 1 (Mg/Si∼1) were β'' and Q' phases. During the thermal exposure process, the L phases remained stable without coarsening, which was mainly due to the high coherence and low interfacial energy of the L-matrix interface. Meanwhile, the main Fe-containing phases in Mg/Si∼2 and Mg/Si∼1 alloys were fine near-spheroidal α-AlFeSi and large-size needle-like β-AlFeSi, respectively, which lead to a better ductility of Mg/Si∼2 alloys. This work may provide a strategy for the preparation of 6xxx series alloys with high thermal stability.

A Lithiophilic–Lithiophobic Gradient Solid Electrolyte Interface Toward a Highly Stable Solid‐State Polymer Lithium Metal Batteries

AbstractThe functional lithiophilic−lithiophobic gradient solid electrolyte interphase (SEI) between Li‐metal anode and solid‐state polymer electrolytes may be effective in addressing the long‐standing issue of side reactions and Li‐dendrite growth during repeated deposition or dissolution in solid‐state polymer‐based high‐energy‐density batteries. Herein, a reliable lithiophilic–lithiophobic gradient SEI (G‐SEI) of LiAg‐LiF/Li3N is in situ formed by AgTFSI, used as an additive for polyethylene oxide‐based electrolyte (PEO‐Ag). The upper layer consists of a lithiophobic LiF/Li3N‐rich layer, wherein LiF possesses a high interfacial energy, while Li3N enables fast Li+ diffusion, which synergistically facilitates the uniform deposition of Li+. Lithiophilic Li–Ag alloy can effectively reduce the nucleation overpotential and promote more planar growth of lithium. Furthermore, such G‐SEI possesses a high mechanical modulus, mitigating the penetration of dendrites through the SEI and thereby preventing the continuous degradation of the PEO‐based electrolyte. As a result, an over three times improvement in the lifespan of Li | PEO‐Ag | LFP cell is achieved, demonstrating an 81.4% capacity retention rate after 500 cycles at 1C, as compared to Li | PEO | LFP cell with common SEI. Thus, the developments of the lithiophilic‐lithiophobic gradient SEI provide a substantial path toward high‐performance solid‐state lithium batteries.

SnF2‐Induced Multifunctional Interface‐Stabilized Li5.5PS4.5Cl1.5‐Based All‐Solid‐State Lithium Metal Batteries

AbstractCompared to traditional lithium‐ion batteries with liquid electrolytes, all‐solid‐state lithium batteries have attracted extensive attention due to their heightened safety and energy density. Lithium argyrodite materials are promising solid electrolytes (SE) due to their high ionic conductivity, low grain boundary resistance, and favorable mechanical properties. However, the poor chemical/electrochemical stability of lithium argyrodite electrolytes toward the bare lithium metal anode inhibits their applications in all‐solid‐state lithium metal batteries (ASSLMBs). Here, Li‐SnF2 composite anodeswas used to induce the formation of solid electrolyte interphase (SEI) composed of LiCl, LiF, and Li22Sn5 at the Li/SE interface. The high interface energy barriers for LiF and LiCl induces the uniform deposition of lithium ions, thus hindering the growth of lithium dendrites. Meanwhile, the fast Li‐ion diffusion coefficient of the Li22Sn5 alloy accelerates Li‐ion migration across the interface section. The symmetrical cell exhibits stable cycling performance over long durations over 300 h at 0.5 mA cm−2. Moreover, the LiNbO3@NCM712/Li5.5PS4.5Cl1.5/Li‐10%SnF2 battery delivers a high initial discharge capacity of 170.9 mAh g−1 at 0.1C and retains 72.9% of its original capacity after 500 cycles at 0.5C. The facial approach for Li‐SnF2 composite anode enables the production of ASSLMBs with superior electrochemical performance.

High-Toughness CO2-Sourced Ionic Polyurea Adhesives.

Polyurea (PUa) adhesives are renowned for their exceptional adhesion to diverse substrates even in harsh environments. However, the presence of quadruple bidentate intermolecular hydrogen bonds in the polymer chains creates a trade-off between cohesive energy and interfacial adhesive energy. To overcome this challenge, a series of CO2-sourced ionic PUa adhesives with ultratough adhesion to various substrates are developed. The incorporated ionic segments within the adhesive serve to partially mitigate the intermolecular hydrogen bonding interactions while conferring unique electrostatic interactions, leading to both high cohesive energy and interfacial adhesive energy. The maximum adhesive strength of 10.9MPa can be attained by ionizing the CO2-sourced PUa using bromopropane and subsequently exchanging the anion with lithium bis(trifluoromethylsulfonyl)imide. Additionally, these ionic PUa adhesives demonstrate several desirable properties such as low-temperature stability (-80°C), resistance to organic solvents and water, high flame retardancy, antibacterial activity, and UV-fluorescence, thereby expanding their potential applications. This study presents a general and effective approach for designing high-strength adhesives suitable for a wide array of uses.

Porous Polyethylene Supports in Reinforcement of Multiblock Hydrocarbon Ionomers for Proton Exchange Membranes.

Hydrocarbon (HC)-based block copolymers have been recognized as promising candidates for proton exchange membranes (PEMs) due to their distinct hydrophilic-hydrophobic separation, which results in improved proton transport compared to that of random copolymers. However, most PEMs derived from HC-based ionomers, including block copolymers, encounter challenges related to durability in electrochemical cells due to their low mechanical and chemical properties. One method for reinforcing HC-based ionomers involves incorporating the ionomers into commercially available low surface tension PTFE porous substrates. Nevertheless, the high interfacial energy between the hydrocarbon-based ionomer solution and PTFE remains a challenge in this reinforcement process, which necessitates the application of surface energy treatment to PTFE. Here, multiblock sulfonated poly(arylene ether sulfone) (SPAES) ionomers are being reinforced using untreated PE on the surface, and this is compared to reinforcement using surface-treated porous PTFE. The PE support layer exhibits a lower surface energy barrier compared to the surface-treated PTFE layer for the infiltration of the multiblock SPAES solution. This is characterized by the absence of noticeable voids, high translucency, gas impermeability, and a physical and chemical stability. By utilizing a high surface tension PE support with a comparable value to the multiblock SPAES, effective reinforcement of the multiblock SPAES ionomers is achieved for a PEM, which is potentially applicable to various hydrogen energy-based electrochemical cells.

PVDF-HFP via Localized Iodization as Interface Layer for All-Solid-State Lithium Batteries with Li6PS5Cl Films.

All-solid lithium (Li) metal batteries (ASSLBs) with sulfide-based solid electrolyte (SEs) films exhibit excellent electrochemical performance, rendering them capable of satisfying the growing demand for energy storage systems. However, challenges persist in the application of SEs film owing to their reactivity with Li metal and uncontrolled formation of lithium dendrites. In this study, iodine-doped poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) as an interlayer (PHI) to establish a stable interphase between Li metal and Li6PS5Cl (LPSCl) films is investigated. The release of I ions and PVDF-HFP produces LiI and LiF, effectively suppressing lithium dendrite growth. Density functional theory calculations show that the synthesized interlayer layer exhibits high interfacial energy. Results show that the PHI@Li/LPSCl film/PHI@Li symmetrical cells can cycle for more than 650h at 0.1mA cm-2. The PHI@Li/LPSCl film/NCM622 cell exhibits a distinct enhancement in capacity retention of ≈26% when using LiNi0.6Mn0.2Co0.2O2 (NCM622) as the cathode, compared to pristine Li metal as the anode. This study presents a feasible method for producing next-generation dendrite-free SEs films, promoting their practical use in ASSLBs.

A tailored dual-layer electronic shielding interface enables highly stable and dendrite-free solid-state lithium metal batteries

All-solid-state lithium metal batteries (ASSLMBs) have emerged as promising energy storage devices due to their high energy density and enhanced safety features. However, challenges related to Li/electrolyte interface stability and ion transport efficiency hinder the practical implementation of sulfide-based ASSLMBs. In this study, we tailored the Li anode interface from the conventional mosaic structure to dual-layer gradient structure through a simple conversion reaction with an organic fluoride. The dual-layer multifunctional interface consists of a highly flexible and wettable upper layer enriched with organic LiBASF3 compounds and an LiF-rich lower layer with high interfacial energy. Eventually, the glittering integration of targeted surface smoothness, excellent interfacial wettability, and high interfacial energy is verified by experimental and theoretical calculation results. The insulating property of the dual-layer interface can impede electronic tunneling and minimize current leakage into the sulfide solid-state electrolytes. Ultimately, the implementation of interface engineering has shown significant improvements in enhancing the critical current density (CCD, 1.9 mA cm−2) of symmetric batteries, as well as enhancing the long-term cycling stability and capacity retention rate of the FeS2 and LiCoO2 cathodes based full cells.

Amphiphilic Heterografted Molecular Bottlebrushes with Tertiary Amine-Containing Side Chains as Efficient and Robust pH-Responsive Emulsifiers.

By combining the unique characteristics of molecular bottlebrushes (MBBs) and the properties of stimuli-responsive polymers, we show that MBBs with randomly grafted poly(n-butyl acrylate) and pH-responsive poly(2-(N,N-diethylamino)ethyl methacrylate) (PDEAEMA) side chains are efficient and robust pH-responsive emulsifiers. Water-in-toluene emulsions were formed at pH 4.0 and disrupted by increasing the pH to 10.0. The emulsion generation and disruption was reversible over the ten cycles investigated, and the bottlebrushes remained intact. The exceptional emulsion stability stemmed from the high interfacial binding energy of MBBs, imparted by their large molecular size and Janus architecture at the interface, as evidenced by the interfacial jamming and wrinkling of the assemblies upon reducing the interfacial area. At pH 10.0, PDEAEMA became water-insoluble, and the MBBs desorbed from the interface, causing de-emulsification. Consequently, we have shown that the judicious design of MBBs can generate properties of particle emulsifiers from their large size, while the responsiveness of the MBBs enables more potential applications.

Amphiphilic Heterografted Molecular Bottlebrushes with Tertiary Amine‐Containing Side Chains as Efficient and Robust pH‐Responsive Emulsifiers

AbstractBy combining the unique characteristics of molecular bottlebrushes (MBBs) and the properties of stimuli‐responsive polymers, we show that MBBs with randomly grafted poly(n‐butyl acrylate) and pH‐responsive poly(2‐(N,N‐diethylamino)ethyl methacrylate) (PDEAEMA) side chains are efficient and robust pH‐responsive emulsifiers. Water‐in‐toluene emulsions were formed at pH 4.0 and disrupted by increasing the pH to 10.0. The emulsion generation and disruption was reversible over the ten cycles investigated, and the bottlebrushes remained intact. The exceptional emulsion stability stemmed from the high interfacial binding energy of MBBs, imparted by their large molecular size and Janus architecture at the interface, as evidenced by the interfacial jamming and wrinkling of the assemblies upon reducing the interfacial area. At pH 10.0, PDEAEMA became water‐insoluble, and the MBBs desorbed from the interface, causing de‐emulsification. Consequently, we have shown that the judicious design of MBBs can generate properties of particle emulsifiers from their large size, while the responsiveness of the MBBs enables more potential applications.