Multifunctional Interphase Research Articles

In Situ Construction of a Multifunctional Interphase Enabling Continuous Capture of Unstable Lattice Oxygen Under Ultrahigh Voltages.

The use of nickel-rich layered materials as cathodes can boost the energy density of lithium batteries. However, developing a safe and long-term stable nickel-rich layered cathode is challenging primarily due to the release of lattice oxygen from the cathode during cycling, especially at high voltages, which will cause a series of adverse effects, leading to battery failure and thermal runaway. Surface coating is often considered effective in capturing active oxygen species; however, its process is rather complicated, and it is difficult to maintain intact on the cathode with large volume changes during cycling. Here, we propose an in situ construction of a multifunctional cathode/electrolyte interphase (CEI), which is easy to prepare, repairable, and, most importantly, capable of continuously capturing active oxygen species during the entire life span. This unique protective mechanism notably improves the cycling stability of Li||LiNi0.8Co0.1Mn0.1O2 (NCM811) cells at rigorous working conditions, including ultrahigh voltage (4.8 V), high temperature (60 °C), and fast charging (10 C). An industrial 1 A h graphite||NCM811 pouch cell achieved stable operation of 600 cycles with a capacity retention of 79.6% at 4.4 V, exhibiting great potential for practical use. This work provides insightful guidance for constructing a multifunctional CEI to bypass limitations associated with high-voltage operations of nickel-rich layered cathodes.

Non-destructive chemical prelithiation of VO2(B) anodes constructing a multifunctional interphase layer for advanced Li-Ion batteries

VO2(B) stands as a promising anode material, comparable to the disordered rock-salt phase Li3+xV2O5, owning to its ease of preparation, suitable redox potential, and remarkable rate capability. However, the practical application of VO2(B) anodes faces substantial limitations due to its low initial coulombic efficiency (ICE) and instability of solid electrolyte interface (SEI) layer during cycling. In this study, we introduce a highly efficient, controllable, and non-destructive chemical prelithiation method utilizing a reductive Li-arene reagent, formed by dissolving Li-metal to THF solutions containing biphenyl derivatives. This method enables the VO2(B) anode to achieve an ICE of nearly 100 %. The investigation on the chemical composition and mechanical properties of SEI layers reveals that the prelithiated VO2(B) electrode contains a more favorable LiF component, fewer adverse byproducts, and exhibits a thinner thickness with high structural strength. Kinetic analysis demonstrates that the prelithiation treatment accelerates the diffusion of lithium ions, reduces interfacial reaction resistances, and maintains interface stability during cycling. To demonstrate the practical application, we assemble a well-designed Prelithiation VO2(B)||NCM811 full cell, achieving an enhancement in the energy density of at least 20 %. This work underscores the potential of prelithiated VO2(B) electrodes for developing lithium-ion batteries (LIBs) with high-safety and high-energy/power density.

Zincophilic Interfacial Manipulation against Dendrite Growth and Side Reactions for Stable Zn Metal Anodes.

Constructing multifunctional interphases to suppress the rampant Zn dendrite growth and detrimental side reactions is crucial for Zn anodes. Herein, a phytic acid (PA)-ZnAl coordination compound is demonstrated as a versatile interphase layer to stabilize Zn anodes. The zincophilic PA-ZnAl layer can manipulate Zn2+ flux and promote rapid desolvation kinetics, ensuring the uniform Zn deposition with dendrite-free morphology. Moreover, the robust PA-ZnAl protective layer can effectively inhibit the hydrogen evolution reaction and formation of byproducts, further contributing to the reversible Zn plating/stripping with high Coulombic efficiency. As a result, the Zn@PA-ZnAl electrode shows a lower Zn nucleation overpotential and higher Zn2+ transference number compared with bare Zn. The Zn@PA-ZnAl symmetric cell exhibits a prolonged lifespan of 650 h tested at 5 mA cm-2 and 5 mAh cm-2 . Furthermore, the assembled Zn battery full cell based on this Zn@PA-ZnAl anode also delivers decent cycling stability even under harsh conditions.

Zincophilic Interfacial Manipulation against Dendrite Growth and Side Reactions for Stable Zn Metal Anodes

AbstractConstructing multifunctional interphases to suppress the rampant Zn dendrite growth and detrimental side reactions is crucial for Zn anodes. Herein, a phytic acid (PA)‐ZnAl coordination compound is demonstrated as a versatile interphase layer to stabilize Zn anodes. The zincophilic PA‐ZnAl layer can manipulate Zn2+ flux and promote rapid desolvation kinetics, ensuring the uniform Zn deposition with dendrite‐free morphology. Moreover, the robust PA‐ZnAl protective layer can effectively inhibit the hydrogen evolution reaction and formation of byproducts, further contributing to the reversible Zn plating/stripping with high Coulombic efficiency. As a result, the Zn@PA‐ZnAl electrode shows a lower Zn nucleation overpotential and higher Zn2+ transference number compared with bare Zn. The Zn@PA‐ZnAl symmetric cell exhibits a prolonged lifespan of 650 h tested at 5 mA cm−2 and 5 mAh cm−2. Furthermore, the assembled Zn battery full cell based on this Zn@PA‐ZnAl anode also delivers decent cycling stability even under harsh conditions.

Ultrastable Sodium/Potassium Metal Anode Enabled by a Multifunctional Interphase Layer with Enhanced Ion Transport Kinetics

AbstractNa (K) metal batteries (NMB and KMB) have gained tremendous attention as large‐scale energy storage systems because of their high specific capacity, low working potential, and natural abundance. However, severe Na dendrite growth hinders the practical application of Na (K) anode. Here, a multifunctional interphase layer consisting of fast‐ion conductive Na–Bi (K–Bi) alloy and sodiophilic (potassiophilic) Na3VO4 (K3VO4) phases, which i derived from a spontaneous reaction (denoted as BVO@Na or BVO@K), is proposed and prepared. The designed electrode exhibits enhanced ion transport kinetics and homogenous Na (K) deposition behavior, and finally achieving dendrite‐free Na (K) growth. Accordingly, the BVO@Na displays a high Na plating/stripping reversibility of 960 h at 1.0 mA cm−2, 1.0 mAh cm−2, and the BVO@K electrode can be operated a cycle lifespan of 870 h under 1.0 mA cm−2, 2.0 mAh cm−2 in symmetric cells. In BVO@Na||Na3V2(PO4)3 full battery, it shows remarkable cycling stability (91% of capacity retention after 1900 cycles) and a high energy density of 281 Wh kg−1 at a power density of 16.2 kW kg−1. The findings lend credence to the prospect of the multifunctional interface layer contributing to the design of a protective layer for alkali metal anodes.

A Multifunctional Interphase Layer Enabling Superior Sodium-Metal Batteries under Ambient Temperature and -40°C.

The sodium (Na)-metal anode with high theoretical capacity and low cost is promising for construction ofhigh-energy-density metal batteries. However, the unsatisfactory interface between Na and the liquid electrolyte induces tardy ion transfer kinetics and dendritic Na growth, especially at ultralow temperature (-40°C). Herein, an artificial heterogeneous interphase consisting of disodium selenide (Na2 Se) and metal vanadium (V) is produced on the surface of Na (Na@Na2 Se/V) via an in situ spontaneous chemical reaction. Such interphase layer possesses high sodiophilicity, excellent ionic conductivity, and high Young's modulus, which can promote Na-ion adsorption and transport, realizing homogenous Na deposition without dendrites. The symmetric Na@Na2 Se/V cell exhibits outstanding cycling life span of over 1790h (0.5mA cm-2 /1 mAh cm-2 ) in carbonate-based electrolyte. More remarkably, ab initio molecular dynamics simulations reveal that the artificial Na2 Se/V hybrid interphase can accelerate the desolvation of solvated Na+ at -40°C. The Na@Na2 Se/V electrode thus exhibits exceptional electrochemical performance in symmetric cell (over 1500h at 0.5mA cm-2 /0.5 mAh cm-2 ) and full cell (over 700 cycles at 0.5 C) at -40°C. This work provides an avenue to design artificial heterogeneous interphase layers for superior high-energy-density metal batteries at ambient and ultralow temperatures.

Negatively charged polymeric interphase for regulated uniform lithium-ion transport in stable lithium metal batteries

Li metal anode (LMA) for practical Li-metal batteries suffers from safety hazards and capacity deterioration caused by its high reactivity and infinite volume change. Herein, a stable LMA with highly uniform surface potential distribution was demonstrated by coating Li with a negatively charged artificial solid electrolyte interphase (ASEI), which is formed by spontaneous in-situ polymerization of 2,3,7,8-tetrakis((trimethylsilyl)ethynyl)pyrazino[2,3- g ]quinoxaline-5,10-dione (PPQ) at room temperature. As an ion-transport regulator, such an ASEI with negatively charged moieties provides preferential Li-ion transport with high Li-ion transference number ( t Li + = 0.74). As a robust artificial layer, the PPQ-stabilized Li (PPQ-Li) maintains high mechanical strength (Young’s modulus of 7.39 GPa) after being immersed in electrolyte, which readily suppresses formation of hazardous Li dendrites and diminishes parasitic reactions on LMA, leading to dendrite-free morphology after long-term Li stripping-plating tests. Such a multi-functional interphase could potentially promote more tailorable coating designs for practically durable LMA. A negatively charged artificial solid electrolyte interphase (SEI) provides preferential Li-ion transport with high Li-ion transference number ( t Li + = 0.74), readily suppresses formation of hazardous Li dendrites, and diminishes parasitic reactions on Li metal anode, leading to dendrite-free morphology after long-term Li stripping-plating tests. • A negatively charged artificial solid electrolyte interphase (ASEI) is formed. • High Li-ion transference number (0.74) was achieved due to the repulsion of anions. • High mechanical strength of the ASEI readily suppresses formation of Li dendrites. • Symmetric cell presented lower voltage hysteresis and stabilized cycling life.

Mechanism Study of Unsaturated Tripropargyl Phosphate as an Efficient Electrolyte Additive Forming Multifunctional Interphases in Lithium Ion and Lithium Metal Batteries.

Electrolytes in modern Li ion batteries (LIBs) rely on additives of various structures to generate key interphasial chemistries needed for desired performances, although how these additives operate in battery environments remains little understood. Meanwhile, these traditional additives face increasing challenges from emerging battery chemistries, especially those based on the nickel cathode (Ni ≥ 50%) or the metallic lithium anode. In this work, we report a new additive structure with the highest unsaturation degree known so far along with the in-depth understanding of its breakdown mechanism on those aggressive electrode surfaces. Tripropargyl phosphate (TPP) containing three carbon-carbon triple bonds was found to form dense and protective interphases on both NMC532 cathode as well as graphitic and metallic lithium anodes, leading to significant improvements in performances of both LIBs and lithium metal batteries (LMBs). Comprehensive characterizations together with calculations reveal how the unsaturation functionalities of TPP interact with these electrode chemistries and establish interphases that inhibit gas generation, suppress lithium dendrite growth, and prevent transition metal ion dissolution and deposition on the anode surface. The correlation established among the additive structure, interphasial chemistries, and cell performance will doubtlessly guide us in designing the electrolytes with atomistic precision for future battery chemistries.

Sulfide-Compatible Conductive and Adhesive Glue-Like Interphase Engineering for Sheet-Type All-Solid-State Battery.

An all-solid-state lithium battery based on a sulfide electrolyte is one of the most promising next-generation energy storage systems. However, the high interfacial impedance, particularly due to the internal pores in the electrode or electrolyte layers, is the major limiting factor to the development of sheet-type all-solid-state batteries. In this study, a low-resistance integrated all-solid composite electrode is developed using a hybrid of a pyrrolidinium-based ionic liquid and a polyethylene oxide polymer with lithium salt as a multifunctional interphase material, which is engineered to be compatible with the sulfide electrolyte as well as the fabrication process of sheet-type composite electrode. The interphase material fills the pore in the composite sheet while binding the components together, which effectively increases the interfacial contact area and strengthens the physical network between the components, thereby enabling enhanced ion transport throughout the electrode. The interphase-engineered sheet-type LiNi0.8 Co0.1 Mn0.1 O2 /Li10 GeP2 S12 electrode shows a high reversible capacity of 166 mAh g-1 at 25 °C, corresponding to 92% of the observed capacity in a current liquid-based cathode system, as well as enhanced cycle and rate performances. This study proposes a novel and practical method for the development of high-performance sheet-type all-solid-state lithium batteries.

Constructing Multifunctional Interphase between Li1.4Al0.4Ti1.6(PO4)3 and Li Metal by Magnetron Sputtering for Highly Stable Solid‐State Lithium Metal Batteries

AbstractDue to high ionic conductivity and low cost, Li1.4Al0.4Ti1.6(PO4)3 (LATP) has emerged as a promising solid‐state electrolyte for next‐generation lithium (Li) metal solid‐state batterie with high safety performance and energy density. However, the extremely high impedance and surface instability of LATP with Li metal retard its practical application. Herein, a novel method is proposed to construct an ultrathin ZnO layer that is tightly coated on the LATP pellets, surface (ZnO@LATP) via magnetron sputtering, which in situ reacts with Li to form a low electronic conductivity and multifunctional solid electrolyte interphase (SEI). The formed SEI can not only effectively lower the interfacial resistance, but also overcome the side reactions of LATP with the Li metal anode and suppress the Li dendrite growth. Specifically, the interface resistance decreases from 80 554 to 353 Ω and the overpotential reduces from 1 V to 20 mV. As a result, the Li/ZnO@LATP@ZnO/Li symmetric batteries can stably cycle for more than 2000 h without short circuit at 0.05 mA cm−2 and Li/ZnO@LATP/LiFePO4 batteries show excellent cycle stability for 200 cycles at 0.1 C. This work highlights the significance of multifunctional interphase between LATP and Li metal for improvement of interfacial impedance and instability.

Sulfide-Compatible Multifunctional Interphase Engineering for Sheet-Type All Solid State Battery

An all-solid-state battery (ASSB) is now accepted as one of promising next-generation rechargeable batteries, since it has a potential to solve the chronic anxiety of safety issue in the current liquid-electrolyte-based lithium-ion battery (LIB) as well as to achieve higher energy density. Of various solid electrolytes for ASSB, sulfide-based solid electrolytes are regarded as more suitable for bulk-type ASSB because of its high conductivity and appropriate mechanical properties such as ductile modulus; It allows the processes of slurry-based sheet coating and cold-pressing required for fabrication of a large areal cell. The bulk-type ASSB, however, has a difficulty yet in increasing reversible capacity and cycle-life because contact area between solid electrolyte and active electrode material is still limited, which is decisive for the cell kinetics. In this presentation, we introduce an ionically-conductive and mechanically-adhesive multifunctional interphase engineering to apply it as both binder and pore-filling agent in all-solid-state composite electrode. The interphase material is hybrid type of ionic liquid and polymer, which is sticky and slightly soft so that build up stable interface between components in the composite electrode. Such combination enables various polymers to be well-mixed in a xylene-based slurry for sulfide-based sheet-type ASSB. The slurry-coated composite electrode showed highly-conductive and well-adhesive physical properties, and finally delivered excellent electrochemical performance in ASSB system. The proposed electrode design and fabrication method can be an effective way to achieve high performance sheet-type sulfide-based ASSB.

In Situ Damage Detection for Fiber‐Reinforced Composites Using Integrated Zinc Oxide Nanowires

AbstractA multifunction material that increases strength is capable of harvesting energy from ambient vibration and acts as a structural health monitoring system is presented. Current in situ damage detection of fiber‐reinforced composites typically uses methods which require external sensors, precise initial measurements for each component under evaluation, or input current to the structure. To overcome these limitations, this work utilizes a multifunctional interphase of piezoelectric zinc oxide nanowires integrated into fiber‐reinforced composites to provide an in situ ability to sense damage. The nanowires are grown onto insulating reinforcing fibers which are sandwiched between carbon fiber electrodes, thus fully integrating the sensing element into the fiber‐reinforced composite. The fully distributed nanowire interphase proves capable of detecting multiple damage modes using passive voltage measurements as demonstrated during multiple loading configurations. This work also analyzes voltage emissions corresponding to damage to provide signal characteristics corresponding to the damage state of the specimen to indicate damage progression and the approach of catastrophic failure. The result of this work is thus a multifunctional structural material with damage detection capabilities. The principles investigated in this work can also be extended to alternative structural composites containing integrated piezoelectric materials in the form of nanoparticles, nanowires, or films.

Commingled Yarn Spinning for Thermoplastic/Glass Fiber Composites

Online commingled yarns were spun with three different polymeric matrices, namely polypropylene (PP), polyamide (PA) and polylactic acid (PLA) and glass fibers. Tailored sizings were applied for the three matrices and the resulting mechanical performance of unidirectional composites was evaluated and compared. Significant improvements in the fiber/matrix bonding were achieved by employed sizing chemistry in order to achieve multifunctional interphases. The pure silane coupling agents provide the best performance for all matrices investigated. However, an additional film former has to be added in order to achieve fiber processing. Film formers compatible to the matrices investigated were adapted. The consolidation behavior during isothermal molding was investigated for polypropylene matrix. Different fiber volume contents could be realized and the resulting mechanical properties were tested.

Carbon fiber/Si3N4 composites with SiC nanofiber interphase for enhanced microwave absorption properties

Abstract In this paper, SiC nanofibers (SiCNFs) as multifunctional interphase were prepared on carbon fibers via catalysis chemical vapor deposition (CCVD) in order to improve the microwave absorption for carbon fiber reinforced silicon nitride (CFs/Si3N4) composites. Experimental results indicated that the chemical compatibility between CFs and Si3N4 matrix under high temperature could be effectively improved by incorporating SiCNFs interphase. Additionally, the dielectric responses and microwave absorbing performance of CFs/Si3N4 composites are significantly influenced by the mass fraction of SiCNFs on CFs. An optimal reflection loss (RL) of −14 dB and 96% absorbing bandwidth (BW) of X-band could be achieved in the CFs/Si3N4 composites with 8 wt% of SiCNFs. Furthermore, experimental points of permittivity in Cole-Cole plane are inclined to distribute on distinguishing circular arcs, corresponding to three types of electric polarization modes. It is concluded that the hopping relaxation of electrons between SiCNFs plays more pronounced contribution to the superior microwave attenuation capability of CFs/Si3N4 composites with SiCNFs interphase than the relaxation loss of free electrons inside short CFs.

Multifunctional Interphases: Percolation Behavior, Interphase Modification, and Electro‐Mechanical Response of Carbon Nanotubes in Glass Fiber Polypropylene Composites

Carbon nanotube dispersions have been immersedin a maleated polypropylene film former system andapplied to insulating glass filament yarns compatible to polypropylene matrix. The percolation threshold can be reached below 0.5 wt% carbon nanotubecontent. In order to achieve a homogeneous multifunctional interphase, the average sizing thickness must be above 450 nm tailored during a coating process by varying the solid content of the sizing. The temperature and the velocity of the coating process have a great impact on the volume resistivity of the multifunctional interphase. Electro‐mechanical behavior as sensors in unidirectional composites containing 50 vol% glass fiber reinforcement is monitored during tensile and compression loading. The largest electrical sensitivity is achieved for tensile loading in the axis of fibers.

Multifunctional interphases for polymeric engineering products and smart devices

Multifunctional interphases for polymeric engineering products and smart devices

Grafting of silane and graphene oxide onto PBO fibers: Multifunctional interphase for fiber/polymer matrix composites with simultaneously improved interfacial and atomic oxygen resistant properties

Abstract Atomic oxygen (AO) is a dominant component of the low earth orbit and can erode most spacecraft materials. In this work, both silane and graphene oxide (GO) were introduced onto poly(p-phenylene benzobisoxazole) (PBO) fibers to prevent AO from penetrating into the interface of PBO fiber/epoxy composites. The microstructure, mechanical properties and AO erosion resistance of PBO fibers before and after modification were investigated. Experimental results revealed that the GO was successfully grafted onto PBO fibers using 3-aminopropyltrimethoxysilane (APTMS) as the bridging agent. The surface roughness (Ra) and wettability of the obtained hybrid fibers (PBO–APTMS–GO) were obviously increased in comparison with those of an untreated one. In addition, PBO–APTMS–GO showed simultaneously remarkable enhancement in interfacial shear strength (IFSS) and AO erosion resistance. Meanwhile, single filament tensile strength (TS) had no obvious decrease after the grafting processes. We believe the facile and effective method may provide a novel interface design strategy for developing multifunctional fibers.