Interfacial Impedance Research Articles

The introduction of carbon nanosheet buffer layer for enhanced hydrogen evolution performance of C3N4/CoP photocatalysts

Various defects of nanocomposites inevitably bring some harmful effects on their photoelectric performance, especially considering that interface defects seriously hinder the carrier interfacial transfer. Here, the interface optimization can be realized between graphitic carbon nitride (C3N4) and CoP co-catalyst by the introduction of good conductive carbon nanosheets (CNs). As a result, the defect density of synthesized C3N4/CNs/CoP is reduced to 1.40 × 1012 cm−3 from 2.55 × 1012 cm−3 of C3N4/CoP, and its interface impedance is correspondingly reduced to 34% of that of C3N4/CoP. Therefore, the optimal H2 evolution rate of 5.26 mmol g−1 h−1 and apparent quantum efficiency of 9.27% at 420 nm are realized, which are 4.8 and 8.1 times that of C3N4/CoP photocatalyst in the absence of CNs, respectively. This work provides a general solution to reduce defect density and carrier transfer resistance in nanocomposites by the introduction of a highly conductive buffer layer.

A Bridge between Ceramics Electrolyte and Interface Layer to Fast Li+ Transfer for Low Interface Impedance Solid‐State Batteries

AbstractSolid‐state batteries (SSBs) are regarded as next generation advanced energy storage technology to provide higher safety and energy density. However, a practical application is plagued by large interfacial resistance, owing to solid‐solid interface contact between ceramics electrolytes and Li anode. Introducing polymer‐based coating between electrolytes and Li anode is a feasible strategy to solve this issue. Unfortunately, current polymer is hard to achieve intimate contact at the atomic scale and lacks of a bridge to transfer Li+ quickly between electrolytes and polymer coating. This gives rise to sluggish Li+ transfer dynamics, huge interface impedance and greatly limits the effectiveness of this strategy. Herein, Poly(lithium 4‐styrenesulfonate)(PLSS) is introduced between Li6.5La3Zr1.5Ta0.5O12 (LLZTO) electrolyte and Li anode. The theories and experiments prove the existence of strong coordinating interaction between SO3Li in PLSS and atoms on LLZTO surface. This interaction structures a bridge to migrate Li+ fast across LLZTO/PLSS interface and hence interface impedance is as low as 9 Ω cm2. Moreover, the electron‐blocking feature of PLSS can prevent electrons from tunneling the LLZTO/PLSS interface and combining with Li+ to form dendrite within LLZTO. PLSS‐base cells show improved long‐life cycling for 4700 h at 0.1 mA cm−2 at room temperature.

Asymmetrical interface modification between electrodes and garnet-type electrolyte enabling all-solid-state lithium batteries

Garnet-based all-solid-state lithium batteries are expected to achieve high energy density and safety. However, the distinctly different chemical and electrochemical environment between the electrodes and garnet-type Li6·4La3Zr1·6Ta0·4O12 (LLZTO) electrolyte results in high interfacial impedance that greatly hinders the electrochemical performance. Herein, we propose an asymmetrical interface modification strategy by respectively introducing an ultrathin in-situ polymerized interlayer on the cathode side and a lithiophilic liquid metal coating layer on the Li metal anode side. As a result, the interfacial impedance on both side is significantly reduced to 214 Ω cm2 on the cathode side and 7.45 Ω cm2 on the Li metal anode side due to the intimate contact and enhanced wettability between Li metal and GSSE together with improved conformability on the cathode side and Li ion conductance within the cathode. Therefore, the interface modified LiFePO4||LLZTO||Li all-solid-state battery exhibits excellent cycling performance over 150 cycles with capacity retention of 96.7% and small voltage polarization of 55 mV at 0.1C and 60 °C. This work provides a convenient strategy to alleviate the interfacial issues in all-solid-state batteries.

Development of interfacial strong Interaction-enhanced C-F@CuBi2(Ox/N1-x)4/CN Nano-sheet clusters photocatalysts for the simultaneous degradation of tetracycline and reduced Cr(VI)

Antibiotics and heavy metal contaminants often co-exist in wastewater, but developing photocatalysts that can remove them simultaneously without secondary contamination and with easy recovery remains a huge challenge. Regrettably, conventional nano-photocatalysts have the inherent disadvantages of high reflectance of sunlight and high electron and hole recombination rates, and more importantly, nanoparticles dispersed in water cannot be efficiently recovered. Herein, we report a p-n heterojunction photocatalyst formed by growing CuBi2(Ox/N1-x)4 (CBON) nano-sheets clusters directly on copper foam (CF) surfaces and introducing N-doped carbon material (CN) on CBON. Such unique nanostructures not only allows visible light to be reflected many times internally, which helps to improve the absorption of visible light, but also provides many active sites for photocatalytic processes and the rapid separation of electrons from holes. The CF@CBON/CN enables simultaneous degradation of tetracycline and reduction of Cr(VI) (97.1% and 98.9% respectively). Moreover, the method of growing CBON/CN nano-sheet clusters on CF overcomes a number of problems (increased interfacial charge transfer impedance, poor structural stability and non-uniform distribution, etc.) associated with conventional methods of combining nanomaterials with recyclable substrates (loading, introduction of adhesives and hybridization, etc.). The Rct of CF@CBON/CN approximate 30 ohms, greatly smaller than conventional powder materials. More than 10 cycles can be achieved without any physical recovery and restoration work. DFT analysis shows that the strong interfacial interaction enhances the conductivity and electron transfer efficiency of the nitrogen-doped heterojunction structure. In addition, we built a simulated photocatalytic filtration unit which achieved efficient degradation of TC and reduction of Cr(VI) (92.8% and 95.1% respectively).

Dependence of Skin-Electrode Contact Impedance on Material and Skin Hydration.

Dry electrodes offer an accessible continuous acquisition of biopotential signals as part of current in-home monitoring systems but often face challenges of high-contact impedance that results in poor signal quality. The performance of dry electrodes could be affected by electrode material and skin hydration. Herein, we investigate these dependencies using a circuit skin-electrode interface model, varying material and hydration in controlled benchtop experiments on a biomimetic skin phantom simulating dry and hydrated skin. Results of the model demonstrate the contribution of the individual components in the circuit to total impedance and assist in understanding the role of electrode material in the mechanistic principle of dry electrodes. Validation was performed by conducting in vivo skin-electrode contact impedance measurements across ten normative human subjects. Further, the impact of the electrode on biopotential signal quality was evaluated by demonstrating an ability to capture clinically relevant electrocardiogram signals by using dry electrodes integrated into a toilet seat cardiovascular monitoring system. Titanium electrodes resulted in better signal quality than stainless steel electrodes. Results suggest that relative permittivity of native oxide of electrode material come into contact with the skin contributes to the interface impedance, and can lead to enhancement in the capacitive coupling of biopotential signals, especially in dry skin individuals.

A review on design considerations in polymer and polymer composite solid-state electrolytes for solid Li batteries

The current all-solid-state battery (ASSB) technology must stride through meticulous research work to reap the much-sought benefits of high energy density, stable cycling life and economical fabrication of ASSBs for large scale applications. Among all the prevailing scientific challenges, low room temperature ionic conductivity and interfacial impedance are the major roadblocks which need to be addressed before introducing them in large scale application in the high-power devices such as electric vehicles. Herein, we briefly discuss the background and the advances of polymeric and composite solid electrolyte systems with their fundamental ion transport mechanism, followed by a discussion on understanding the chemistry of various interfaces and interphases phenomena, various types of (in)stability issues, other bottleneck and challenging parameters, and the proposed solution to these in cell design strategies. In addition, this review also critically introspects the current measurement methods for collecting and reporting data on the ionic conductivity and reliability of the acquired data. The insights into these aspects will not only enlighten the readers about the recent trends in polymeric solid electrolytes but also will assist determining the correct type of measurement methods and the right cell design strategies.

Mortise-tenon joints reinforced Janus composite solid-state electrolyte with fast kinetics for high-voltage lithium metal battery

Bilayer composite solid-state electrolytes (CSSEs) are regarded as promising candidates to meet the requirements of high-voltage lithium metal batteries due to their exceptional compatibility with both opposite electrodes. However, such a configuration usually leads to additional interfacial impedance between CSSEs and discontinuous Li+ migration process, resulting in deteriorated electrochemical performances. Herein, a Janus electrolyte with mortise and tenon joints (JCSSE) is proposed for enhancing interfacial compatibility. It is composed of poly (vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP))/Li6.4La3Zr1.4Ta0.6O12 layer toward cathode and poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (PDADMATFSI)/UiO-66-SO3Li layer to Li-metal anode. Such a configuration enables not only intimate contact between the two electrolyte layers, but regulated Li+ coordination environment which would improve Li+ transference number. Both simulation and experimental characterization suggest that the defluorinated-P(VDF-HFP) with low highest occupied molecular orbital (HOMO) and PDADMATFSI with strong adsorption energy toward lithium metal can favor the formation of stable electrode/electrolyte interface. Optimized JCSSE exhibits a high ionic conductivity of 0.21 mS cm−1 at 25°C and a wide electrochemical window of 5.0 V. As a result, Li//JCSSE//LiNi0.8Mn0.1Co0.1O2 battery could deliver remarkable cycling performances at 4.3 V for 100 cycles. In addition, JCSSE enables superior cyclability from 25 to 100°C. High-voltage pouch cells employing JCSSE exhibit unexpected endurance under harsh conditions. This novel Janus electrolyte with tenon and mortise structure will accelerate the commercialization of high-energy-density lithium metal batteries.

The effects of Zn/Cd ratio and GQDs doping on the photoelectric performance of ZnxCd1-xSe

A hydrothermal method was employed to synthesize ZnxCd1-xSe and ZnxCd1-xSe /GQDs nanocomposites. The effects of various Zn/Cd ratios and GQDs doping on the performance of ZnxCd1-xSe were studied. The material composition, crystal structure and photoelectric properties could be adjusted by altering the Zn/Cd ratio. ZnxCd1-xSe material changed from hexagonal phase CdSe to near cubic phase ZnSe with the increased of Zn/Cd ratio from 0.1:0.9 to 0.9:0.1. At the same time, ZnxCd1-xSe material reached the higher photocurrent (3.82 μA cm−2) and lower interface impedance when the Zn/Cd atomic ratio was 0.9/0.1. Compared with the pre-doped, Zn0.9Cd0.1Se/GQDs composites exhibited up to a 2-fold increase in the photocurrent density, and achieved a smaller value in the electrochemical impedance, which indicated that the introduction of GQDs significantly improved the photoelectric performance of semiconductor.

Integrated Design from Microstructural Engineering to Binder Optimization Enabling a Practical Carbon Anode with Ultrahigh ICE and Efficient Potassium Storage.

Potassium-ion batteries (PIBs) are emerging as a powerful alternative to lithium-ion battery systems in large-scale energy storage owing to plentiful resources. Nevertheless, pursuing high-yield anode materials with high initial Coulombic efficiency (ICE) and superior rate capability is still one of the most critical challenges in practical application. Herein, an integrated electrode (PC-x) derived from a petroleum coke precursor (carbon residue rate as high as 89%) is regulated from microstructural engineering to binder optimization devoting to high ICE and efficient potassium storage. Excitingly, with a strong assist from a sodium carboxymethyl cellulose (CMC) binder, the PC-900 anode displays an ultrahigh ICE of 80.5%, one of the highest values reported for PIB carbon anodes. Simultaneously, the PC-900 anode submits a high capacity (304.3 mAh g-1), superb rate (138.2 mAh g-1 at 10C), and excellent stability. Furthermore, the full cell exhibits an outstanding rate and cycling performance (210.7 mAh g-1 at 0.5C), confirming its large-scale application prospects. The ultrahigh ICE and excellent performance are mainly attributable to the beneficial microstructures (low surface area, functional group content, and larger interlayer spacing) created by microstructural engineering. Meanwhile, binder optimization also plays a crucial role in reducing the irreversible capacity and interface impedance, further improving the ICE and rate capability. Importantly, mechanism analysis confirms two-stage K+ storage behavior: reversible adsorption at edges and defects (>0.25 V) and intercalation into crystalline layers (<0.25 V). This work provides an efficient and easily scalable electrode design strategy for future practical applications of PIBs.

An experimentally-validated 3D electrochemical model revealing electrode manufacturing parameters’ effects on battery performance

The Lithium Ion Battery electrodes microstructures and their electrochemical performance are determined by the adopted manufacturing process parameters. However, in view of the strong interdependencies between these parameters, evaluating their influence on the performance is not a trivial task. In our previous publications, we have reported a series of computational models able to predict the influence of manufacturing parameters (e.g. slurry formulation, drying rate, calendering pressure) on the LIB electrodes microstructures. We have also demonstrated 3D-resolved models receiving as an input such predicted microstructures and predicting their electrochemical performance. While the manufacturing models have been experimentally validated by us and that the performance model provided performance predictions close to the experimental ones, a 1-to-1 quantitative comparison between the performance model predictions and experimental discharge curves was not yet explored by us. In this work we present an experimentally validated 3D-resolved electrochemical model of a NMC111-based electrode which reveals how slurry formulation and calendering degree affect the electrode performance. We found that the major factors linking manufacturing parameters and electrode performance are the carbon and binder domain distribution within the electrode volume, and the electrostatic potential difference between the electrode and the current collector. A well-connected electronic conductive network throughout the electrode is vital for ensuring full utilization of active material, and it was found that increasing calendering degree is effective in reducing interfacial impedance. This work uncovers, based on a dual modeling/experimental approach, the essence of how electrode manufacturing process takes effect on electrode performance by influencing its microstructure.

Three-dimensional LLZO/PVDF-HFP fiber network-enhanced ultrathin composite solid electrolyte membrane for dendrite-free solid-state lithium metal batteries

Composite solid electrolyte (CSE) membranes for lithium metal batteries attract great attention with excellent safety and suitable flexibility. Herein, we construct a polyethylene oxide-based ultrathin CSE membrane that is enhanced by a 3D fiber network composed of Poly (vinylidene fluoride-co-hexafluoropropylene) fibers and Li7La3Zr2O12 particles directly fabricated on the cathode. The 3D fiber network facilitates the rapid transport and uniform deposition of Li+, and enhances the mechanical strength of the electrolyte membrane, thereby effectively inhibiting the growth of lithium dendrites. Moreover, the unique preparation method reduces the interfacial impedance, and it can also greatly reduce the electrolyte thickness, which is beneficial to increasing the energy density of the battery. The lithium symmetric battery shows stable cycling over 1500 h under 0.2 mA cm−2. Li/LiFePO4 battery with the CSE membrane exhibits a high reversible capacity of 155.8 mAh·g−1 at 0.2 C for 100 cycles and the capacity retention rate is 98.0%. Furthermore, the obtained CSE membrane has a broadened electrochemical window of 4.83 V, and the reversible capacity of the Li/LiNi0.8Co0.1Mn0.1O2 battery is 160.6 mAh·g−1 at 0.2 C for 100 cycles. These findings showed that the structure proposed here is a viable electrolyte strategy for advanced solid-state lithium metal batteries.

Distinct functional Janus interfaces for dendrite-free Li1.3Al0.3Ti1.7(PO4)3-based lithium metal batteries

The NASICON-type Li1.3Al0.3Ti1.7(PO4)3 (LATP) ceramic electrolyte shows promise for high-energy-density solid-state Li metal batteries (SSLMBs), but its incompatibility and poor interfacial contact with cathode/anode electrode still is a bottleneck problem of the commercial development. Herein, the compatible and effective solid-state electrolyte is devised by coating LATP pellet with distinct functional polymers dependent on respective interface necessities. Specifically, the poly (vinylene carbonate) (PVCA) + tetraethylene glycol dimethyl ether (TEGDME) protective layer is introduced into LATP/LiFePO4 interface via simple in-situ polymerization method, and the polyvinylidene fluoride hexafluoropropylene (PVDF-HFP) + TEGDME protective layer is coated to the LATP surface facing Li anode. We demonstrate that the PVCA layer on the cathode side is closely attached to LiFePO4 along with reduced impedance at LATP/LiFePO4 interface, the PVDF-HFP layer on the anode side protects LATP from being reduced, and TEGDME improves the electrochemical stability window (ESW) and ionic conductivity of the protective layers. Such Janus LATP electrolyte endows SSLMBs with extremely small interfacial impedance (188 Ω), excellent cycling stability (∼ 90% after 300 cycles) and dendritic-free Li anode (3000 h stable cycling) at 60 °C. This study implies that this double-protected interface modification strategy is brilliant in constructing high-performance and dendritic-free SSLMBs for future application.

Cryo‐EM Studies of Atomic‐Scale Structures of Interfaces in Garnet‐Type Electrolyte Based Solid‐State Batteries

AbstractHigh interfacial impedance is a major obstacle in the application of solid‐state Li metal batteries (SSLMBs). Understanding the atomic‐scale structure of the interfaces in SSLMBs is thus critical to their practical implementations. However, due to the beam sensitivity of battery materials, such information is not accessible by conventional electron microscopy (EM). Herein, by using cryogenic‐EM (cryo‐EM), the atomic‐scale structures of interfaces in garnet electrolyte based SSLMBs are revealed. A LiF‐rich interlayer exhibiting intimate contacts with both Li and LLZTO is shown, thus rendering uniform Li+ transport across the interface in turn inhibiting Li dendrite growth. Consequently, the Li symmetric cell based on the LiF‐rich interlayer exhibits a high critical current density of 3.2 mA cm−2 and a long lifespan over 1800 cycles at 1 mA cm−2. Moreover, a full cell with a LiNi0.88Co0.1Al0.02O2 cathode at a high mass loading ≈12 mg cm−2 reached over 400 cycles at 1.2 mA cm−2, which represents a major progress in the performance of the garnet‐type SSLMBs. This study provides atomic‐scale understanding of interfaces in SSLMBs and an effective strategy to design dendrite‐free SSLMBs for practical applications.

Gel Polymer Electrolytes Design for Na-Ion Batteries.

Na-ion battery has the potential to be one of the best types of next-generation energy storage devices by virtue of their cost and sustainability advantages. With the demand for high safety, the replacement of traditional organic electrolytes with polymer electrolytes can avoid electrolyte leakage and thermal instability. Polymer electrolytes, however, suffer from low ionic conductivity and large interfacial impedance. Gel polymer electrolytes (GPEs) represent an excellent balance that combines the advantages of high ionic conductivity, low interfacial impedance, high thermal stability, and flexibility. This short review summarizes the recent progress on gel polymer Na-ion batteries, focusing on different preparation approaches and the resultant physical and electrochemical properties. Reasons for the differences in ionic conductivity, mechanical properties, interfacial properties, and thermal stability are discussed at the molecular level. This Review may offer a deep understanding of sodium-ion GPEs and may guide the design of intermolecular interactions for high-performance gel polymer Na-ion batteries.

In situ polymerization infiltrated three-dimensional garnet-based framework for quasi-solid lithium metal batteries

Solid-state lithium metal batteries (LMBs) using nonflammable solid electrolytes (SEs) are considered to be the new generation of energy storage devices with high energy density and good safety. However, many challenges, such as insufficient room-temperature ionic conductivity of SEs and tremendous electrode-electrolyte interfacial impedance, hinder the commercialization of solid-state LMBs. Here, we reported a novel composite solid electrolyte (CSE), consisting of a three-dimensional (3D) Li6.25Ga0.25La3Zr2O12 (LLZO) nanoparticle-based framework and filled tripropylene gycol diacrylate (TPGDA)-based gel electrolytes, in which the gel electrolytes are prepared by in situ polymerization of the TPGDA monomer in the condition of liquid electrolyte. Owing to the high content of LLZO powder and PVDF binder, the nonflammable CSE shows superior thermal stability and outstanding mechanical property. Moreover, the CSE exhibits high room-temperature ionic conductivity (1.66 × 10−3 S⋅cm−1) due to the large amount of liquid electrolyte loaded in the 3D framework. Besides, in-situ gel electrolytes facilitate the interfacial contact between electrolyte and lithium anode. Therefore, the LiFePO4/CSE/Li cell exhibits excellent cycling stability at room temperature, delivering a capacity retention ratio of 86.5% after 350 cycles at 1 C. This work can provide guidance in designing CSEs for high-performance lithium metal batteries.

An All-in-One, Bioderived, Air-Permeable, and Sweat-Stable MXene Epidermal Electrode for Muscle Theranostics.

Muscle fatigue is a common symptom experienced by many people and associated with less maximal force production of fatigued muscle. It is highly desirable to simultaneously and imperceivably diagnose muscle fatigue and restore muscle function using one skin electrode, yet no such electrode has been developed so far. Herein, we report an all-in-one, bioderived, air-permeable, and sweat-stable MXene electrode that can concurrently and comfortably record electromyographic (EMG) signals and achieve electrostimulation and electrothermal therapy for muscle theranostics. Leveraging the structural arrangement of perennial herbs and ion cross-linking of MXene in sweat, MXene-based electrodes (MBE) exhibit high breathability, are ultralightweight (∼0.25 mg/cm3), and have low and stable electrode-skin interfacial impedance at a variety of environments, facilitating the long-term reliable monitoring of electrophysiology. Taken together with electrostimulation and electrothermal therapy at the skin surface, MBE can diagnose muscle fatigue and restore muscle function by stimulating blood circulation. In addition, it can also be used for muscle rehabilitation training and prosthesis control via human-computer interaction. Our all-in-one, bioderived, air-permeable, and sweat-stable MXene electrode has a great potential for daily wearable healthcare of muscle fatigue.

An integrated polymer/electrode interface for high performance ceramic/polymer electrolyte-based solid-state lithium batteries

Solid-state batteries (SSBs) are an ideal next-generation energy storage system due to their safety and high energy density. However, many interfacial problems, such as high interfacial resistance and poor compatibility between electrodes and electrolytes, limit the development of SSBs. In this study, an ultrathin interfacial layer composed of poly(ethylene oxide) (PEO) and ethylene carbonate (EC) are in situ fabricated on the surface of electrodes, integrating ceramic/polymer composite electrolyte and electrodes and reducing the interfacial impedance. Meanwhile, the excellent chemical compatibility between PEO and lithium metal effectively improves the interfacial stability. Also, the modification of the interfacial layer leads to more F- participation in the formation of solid electrolyte interphase (SEI), and the relative content of LiF, Li3N, and other by-products increases, which facilitates the formation of dense and stable SEI, thus inhibiting the growth of dendritic lithium and improving the ionic conductivity. With the interfacial layer, a highly stable interface against Li is maintained for more than 1400 h at a current density of 0.1 mA cm−2. A solid-state battery with LiNi0.5Co0.2Mn0.3O2 (NCM523) as the cathode delivers a capacity of 153.4 mAh g−1 and a capacity retention of 92.1% after 100 cycles. This study shows that the interfacial layer PEO-EC is an effective way to improve the performance of SSBs.

Interfacial and Charge-Transport Impedances of NCM Composite Cathodes with Halide Solid Electrolytes for All-Solid-State Batteries

All-solid-state batteries (ASSBs) offer a fundamental solution to mitigate the safety and reliability issues of conventional lithium-ion batteries utilizing flammable liquid electrolytes. However, interfacial resistances between the cathode materials and solid electrolytes, which originate from poor solid-solid contacts and detrimental interfacial reactions, limit the electrochemical performances of ASSBs. Recently, various approaches have been developed to realize high-capacity composite cathodes with improved cycling stability. For example, single-crystal LiNi0.8Co0.1Mn0.1O2 (NCM811) has been reported to mitigate the capacity fading resulting from cracking of commonly adopted multi-crystal NCM811. Also, halide-type solid electrolytes are reported to exhibit high Li-ion conductivity and electrochemical stability with NCM. In this work, we systematically study the interfacial and charge-transport impedances of NCM composite cathodes with halide solid electrolytes. The composite cathodes comprising single- or multi-crystal NCM811 and Li6PS5Cl or Li3InCl6 (and conductive agents) are fabricated to characterize their electrochemical impedance behaviors. In particular, we analyze the evolution of the interfacial and charge-transport impedances during charge–discharge cycling based on a multi-rail transmission line model combined with interfacial reactions. In addition, we investigate the chemical, electrochemical, and mechanical degradations of composite cathodes using various analytical tools to elucidate performance-determining factors of ASSBs.

A Three-Dimensionally Interconnected Composite Polymer Electrolyte for Solid-State Batteries

High energy density of solid-state batteries requires a thin solid electrolyte separator layer (<30 μm), that can sustain high currents and is easily processable. Polymer-ceramic composite electrolytes can potentially fulfill these requirements by combining the advantages of each type. Ceramic electrolytes have high room-temperature ionic conductivity, transference number of one, and mechanical strength to suppress lithium dendrites, whereas polymer electrolytes are easily processable and can form conformable interfaces with the electrodes. High interfacial-impedance between polymer and ceramic electrolytes make the composites with dispersed ceramic particles less attractive.1 A composite electrolyte architecture where a three-dimensionally interconnected porous ceramic is filled with polymer electrolyte, previously reported by our group, can avoid the interfacial impedance issue, although for thin composite membranes, the interfacial impedance between ceramic framework and excess polymer layer on top/bottom surface will still dominate the overall impedance.2 Here we will present fabrication and electrochemical evaluation of ~150 μm thick composite electrolytes with the above-described 3D-interconnected ceramic architecture. The 3-D framework is obtained by partially sintering Ohara ceramic particle tapes obtained via tape casting, which are filled with curable polymer electrolyte precursors. To obtain a thin (5 μm), uniform polymer electrolyte layer on both surfaces, spray coating was employed. The resulting composite membrane exhibited good dendritic resistance in symmetric cell cycling, improved transference number compared to the polymer electrolytes. We also found significantly improved flexibility of the composite electrolytes with plasticization, however, at the cost of reduction in ionic conductivity due to damage to the ceramic network caused by plasticizer-induced swelling of the cross-linked polymer electrolyte. This research was sponsored by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy for the Vehicle Technologies Office’s Advanced Battery Materials Research Program (Tien Duong, Program Manager). This abstract has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). References Chen, X. C.; Liu, X.; Samuthira Pandian, A.; Lou, K.; Delnick, F. M.; Dudney, N. J., Determining and Minimizing Resistance for Ion Transport at the Polymer/Ceramic Electrolyte Interface. ACS Energy Letters 2019, 4 (5), 1080-1085.Palmer, M. J.; Kalnaus, S.; Dixit, M. B.; Westover, A. S.; Hatzell, K. B.; Dudney, N. J.; Chen, X. C., A three-dimensional interconnected polymer/ceramic composite as a thin film solid electrolyte. Energy Storage Materials 2020, 26, 242-249.

Ceramic/Polymer Hybrid Electrolyte with Enhanced Interfacial Contact for All-Solid-State Lithium Batteries

All solid-state lithium batteries (ASSLBs) with a high energy density are challenging, yet desired by the rising energy demands. Its intrinsic safety of solid-state electrolytes (SSEs) compared to flammable liquid electrolytes makes ASSLBs a modern-day necessity. NASICON-type Li1.5Al0.5Ge1.5P3O12 (LAGP) has high ionic conductivity, high stability against air and water, and a wide electrochemical window. However, the application of LAGP is significantly hindered by its slow interfacial kinetics and brittle nature. In addition, the ionic conductivity of LAGP is relatively low at room temperature compared to that obtained at elevated temperatures. In our study, LAGP was incorporated into a polymer matrix to accelerate charge transport at the electrode-electrolyte interface to form LAGP-poly-DOL (LAGP-pDOL) hybrid electrolyte. The in-situ cationic ring-opening polymerization of DOL decreases the interfacial contact impedance and improves the mechanical properties of the SSE. LAGP-pDOL electrolyte exhibits prolonged cycle stability in symmetric cells (> 200 h) and in Li|LiFePO4 full cells (99% retention after 50 cycles) at room temperature. This study demonstrates the effective utilization of conductive polymer matrix into LAGP to enhance mechanical strength, interfacial contact, and room temperature electrochemical performance.