Interface Issues Research Articles

Front Cover: Carbon Neutralization, Volume 1, Issue 2, September 2022

Front cover image: Transition metal layered oxide materials are considered one of the most promising sodium ion batteries cathodes (SIBs), however, poor air stability, complicated interfacial reaction, and irreversible phase translation of layered oxide cathodes pose problems for the long-term cycle as well as rate performance. Surface chemistry engineering could relieve those mentioned above problems. In article number 10.1002/cnl2.19, the effects, processes, and types of surface modification methods used in layered oxide cathodes for SIBs have been comprehensively summarized. Additionally, an innovative concept of interface conversion reaction with bulk penetration doping integration is proposed to attempt to solve interface and bulk issues simultaneously and then implement high-performance cathodes for SIBs.

Emergence of MR-Linac in Radiation Oncology: Successes and Challenges of Riding on the MRgRT Bandwagon.

The special issue of JCM on “Advances of MRI in Radiation Oncology” provides a unique forum for scientific literature related to MR imaging in radiation oncology. This issue covered many aspects, such as MR technology, motion management, economics, soft-tissue–air interface issues, and disease sites such as the pancreas, spine, sarcoma, prostate, head and neck, and rectum from both camps—the Unity and MRIdian systems. This paper provides additional information on the success and challenges of the two systems. A challenging aspect of this technology is low throughput and the monumental task of education and training that hinders its use for the majority of therapy centers. Additionally, the cost of this technology is too high for most institutions, and hence widespread use is still limited. This article highlights some of the difficulties and how to resolve them.

Where specialist and mainstream service systems collide: The National Disability Insurance Scheme in prisons

AbstractThe coordination of specialist with mainstream service systems is prone to role delineation and implementation difficulties worldwide. In the case of the National Disability Insurance Scheme (NDIS), this specialist/mainstream interface is complicated by federalism and funding responsibilities held by different levels of government. People with disability, especially cognitive or intellectual disability, are over‐represented in Australia's prisons. Through semi‐structured interviews with professionals working at the interface of disability and criminal justice, we explore some of these interface issues with regard to NDIS services (specialist) in prisons (mainstream). We find that policy permits some NDIS‐funded services to be delivered inside prisons, such as transition services related to a person's disability, but in practice there is significant variation in how policy is understood and implemented, leading to exclusion and service gaps. This case study shines light on longstanding debates about service coordination across organisational and jurisdictional boundaries.

Usability Evaluation of a Noninvasive Neutropenia Screening Device (PointCheck) for Patients Undergoing Cancer Chemotherapy: Mixed Methods Observational Study.

Patients with cancer undergoing cytotoxic chemotherapy face an elevated risk of developing serious infection as a consequence of their treatment, which lowers their white blood cell count and, more specifically, their absolute neutrophil count. This condition is known as neutropenia. Neutropenia accompanied by a fever is referred to as febrile neutropenia, a common side effect of chemotherapy with a high mortality rate. The timely detection of severe neutropenia (<500 absolute neutrophil count/μL) is critical in detecting and managing febrile neutropenia. Current methods rely on blood draws, which limit them to clinical settings and do not allow frequent or portable monitoring. In this study, we demonstrated the usability of PointCheck, a noninvasive device for neutropenia screening, in a simulated home environment without clinical supervision. PointCheck automatically performs microscopy through the skin of the finger to image the blood flowing through superficial microcapillaries and enables the remote monitoring of neutropenia status, without requiring venipuncture. This study aimed to evaluate the usability of PointCheck, a noninvasive optical technology for screening severe neutropenia, with the goal of identifying potential user interface, functionality, and design issues from the perspective of untrained users. We conducted a multicenter study using quantitative and qualitative approaches to evaluate the usability of PointCheck across 154 untrained participants. We used a mixed method approach to gather usability data through user testing observations, a short-answer qualitative questionnaire, and a standardized quantitative System Usability Scale (SUS) survey to assess perceived usability and satisfaction. Of the 154 participants, we found that 108 (70.1%) scored above 80.8 on the SUS across all sites, with a mean SUS score of 86.1 across all sites. Furthermore, the SUS results indicated that, out of the 151 users who completed the SUS survey, 145 (96%) found that they learned how to use PointCheck very quickly, and 141 (93.4%) felt very confident when using the device. We have shown that PointCheck, a novel technology for noninvasive, home-based neutropenia detection, can be safely and effectively operated by first-time users. In a simulated home environment, these users found it easy to use, with a mean SUS score of 86.1, indicating an excellent perception of usability and placing this device within the top tenth percentile of systems evaluated for usability by the SUS. ClinicalTrials.gov NCT04448314; https://clinicaltrials.gov/ct2/show/NCT04448314 (Hospital Universitario 12 de Octubre registration) and NCT04448301; https://clinicaltrials.gov/ct2/show/NCT04448301 (Boston Medical Center registration).

Bidirectional Interface Protection of a Concentrated Electrolyte, Enabling High-Voltage and Long-Life Aqueous Zn Hybrid-Ion Batteries.

Prussian blue analogues (PBAs) as a promising high-voltage cathode material for aqueous zinc-ion batteries (ZIBs) are usually subjected to an ephemeral lifespan and low Coulombic efficiency due to the irreversible phase change and high Zn2+ insertion potential. Besides, Zn dendrites, H2 evolution reaction, and corrosion derived from a Zn anode interface remain huge challenges. Given this, a highly stable zinc hexacyanoferrate (KZnHCF) cathode together with a mixed concentrated electrolyte is prepared to realize a high-voltage and long-life aqueous ZIB, in which the mixed concentrated electrolyte consisting of 30 m KFSI + 1 m Zn(CF3SO3)2 possesses a unique Zn2+ solvation sheath (Zn(CF3SO3)0.3(FSI)3.1(H2O)2.6) that can not only stabilize the cathode interface and improve the Coulombic efficiency but also fundamentally solve the Zn anode interface issues. As a result, the aqueous KZnHCF/Zn battery achieves an ultralong life over 3000 cycles without any capacity decay even under a high discharge voltage of 1.78 V (vs Zn2+/Zn). Such extraordinary performance represents significant progress in aqueous PBA-based ZIBs. This work shares guidance to improve the performance of aqueous ZIBs through optimizing the electrolyte in tuning the stable operation of the cathode and the zinc anode.

Rational design of nanofibrous scaffolds via bionic coating: Microstructural behavior and in vitro biological evaluation

Fabricating electrospun nanofibrous scaffolds from a combination of inorganic-organic hybrid materials is proposed as a versatile process in bone tissue engineering. However, to enhance or improve the interface issues of biphasic hybrid materials is still a challenge on how to balance the preparation conditions and physicochemical properties. Here, we designed the mussel-inspired surface assembly with copper-doped mesoporous bioactive glass (Cu-MBG) into polylactic acid (PLA) substance to enhance their mechanical and biological performances. The introduction of polydopamine (PDA) into the Cu-MBG matrix was to retain the mesostructure and improve physiological stability. Also, the nanofibrous hybrid scaffolds with/without PDA (i.e., PLA/Cu-MBG@PDA, PLA/Cu-MBG) were fabricated to evaluate the microstructural, mechanical properties, and biological features. The PDA modification in such fibrous structure could not only adjust the physicochemical properties and surface hydrophilicity, but also enhance its tensile strength. PLA/Cu-MBG@PDA exhibited strength of 5.57 MPa and elongation at break of 65.75%, showing an improvement over PLA/Cu-MBG. Extensive in vitro biological evaluation showed that the PLA/Cu-MBG@PDA scaffold exhibited many superior properties such as excellent apatite-formation ability, and enhanced cell viability compared with PLA/Cu-MBG scaffold. The mussel-inspired method provided a facile and effective strategy to combine the merits of organic/inorganic phase in one system, demonstrating its potential application in bone tissue regeneration.

Issues Concerning Interfaces with Inorganic Solid Electrolytes in All-Solid-State Lithium Metal Batteries

All-solid-state batteries have attracted wide attention for high-performance and safe batteries. The combination of solid electrolytes and lithium metal anodes makes high-energy batteries practical for next-generation high-performance devices. However, when a solid electrolyte replaces the liquid electrolyte, many different interface/interphase issues have arisen from the contact with electrodes. Poor wettability and unstable chemical/electrochemical reaction at the interfaces with lithium metal anodes will lead to poor lithium diffusion kinetics and combustion of fresh lithium and active materials in the electrolyte. Element cross-diffusion and charge layer formation at the interfaces with cathodes also impede the lithium ionic conductivity and increase the charge transfer resistance. The abovementioned interface issues hinder the electrochemical performance of all-solid-state lithium metal batteries. This review demonstrates the formation and mechanism of these interface issues between solid electrolytes and anodes/cathodes. Aiming to address the problems, we review and propose modification strategies to weaken interface resistance and improve the electrochemical performance of all-solid-state lithium metal batteries.

Skin‐Like Transparent Sensor Sheet for Remote Healthcare Using Electroencephalography and Photoplethysmography

AbstractThe growing demand for efficient home healthcare applications for brain disorder diagnostics and treatment has inspired the development of wearable devices for monitoring brain activity. However, flexible probes that have improved biocompatibility for wearable devices are markedly affected by noise due to contact interface issues. In this study, a stretchable (≤1500% strain) and transparent (over 85% transmittance) biocompatible electrode that steadily adheres to skin is developed to fabricate an imperceptible sheet‐type device that wirelessly records electroencephalograms (EEGs). The multifunctional characteristic of the electrode results from the double‐network structure in an elastomer/conductive additive blend on a metal‐nanowire‐based track, which contributed to EEG monitoring with ultralow noise (≈0.14 µV noise floor) and sleep‐stage classification. Furthermore, the optical transparency enabled camera‐based photoplethysmography to detect pulse waves and blood oxygen saturation without interfering with the light path, which is a crucial factor in realizing a remote healthcare system.

A Power-Harvesting CGM Chiplet Featuring Silicon-Based Enzymatic Glucose Sensor.

Diabetes has become a leading cause of death and disability in the past decades. Continuous glucose monitoring (CGM) is a prevailing technique to determine the glucose level and provide in-time treatment. However, conventional CGM systems combine an electrochemical sensor with a CMOS chip, suffering from bulky size and interface issues. Integrating the CGM sensor on silicon is potential to miniaturize the CGM system and reduce the cost, while the recent silicon-based sensors show limited detection range and sensitivity. In this work, we present a silicon-based CGM chip let with wireless power transfer (WPT) and real-time wireless telemetry. Fabricated on a single silicon substrate, the chiplet consists of a silicon-based CGM sensor, a power-harvesting wireless-telemetry chip, and a silicon-based antenna. Measured results show that the chip let achieves a sensitivity of 4 μA.mM.cm-2 and a linear detection range of 0-10 mM. Based on WPT and backscattering communication, the chip let consumes 18.8 μ W power in glucose telemetry.

The Correlation between Structure, Surface, and Performance in Fe- and Mg-Substituted LiNi0.5Mn1.5O4 Cathodes

A need for lithium-ion cathodes that have a reduced dependence on scarce elements, such as cobalt, has been prompted by surge in eco-consciousness over the past decade. The spinel-type LiNi0.5Mn1.5O4 (LNMO) cathodes, with high operating voltages (ca. 4.7V vs Li+/Li) and energy densities (ca. 650 Wh kg-1), have received particular attention for this reason.1 Poor cycling stability, however, which arises from structural instabilities, electrolyte degradation, surface densification and loss of active material through transition metal dissolution, limits their widespread adoption.2 Elemental substitution has been employed to overcome such limitations, in which improved cycling stability has been observed. In such samples, the segregation of substituents to the cathode surface has been reported, yet the effect of surface segregation on the local atomic structure and surficial reactivity of the cathodes is under-researched.3 To further explore these areas, Fe- and Mg-substituted LNMO samples have been synthesised. Despite lower initial capacity, Mg-substituted LNMO exhibits significantly improved cycling stability over 300 cycles at 50°C. A combination of x-ray and neutron diffraction, neutron pair distribution function analysis, and x-ray absorption and photoelectron spectroscopy are used to explore the complex relationships between bulk structure, local structure, surface reactivity and performance in Fe- and Mg-substituted LNMO cathodes. References Liang, G., Peterson, V.K., See, K.W., Guo, Z., and Pang, W.K. (2020). Developing high-voltage spinel LiNi 0.5 Mn 1.5 O 4 cathodes for high-energy-density lithium-ion batteries: current achievements and future prospects . J. Mater. Chem. A.Ma, J., Hu, P., Cui, G., and Chen, L. (2016). Surface and Interface Issues in Spinel LiNi0.5Mn1.5O4: Insights into a Potential Cathode Material for High Energy Density Lithium Ion Batteries. Chem. Mater. 28, 3578–3606.Shin, D.W., Bridges, C.A., Huq, A., Paranthaman, M.P., and Manthiram, A. (2012). Role of Cation Ordering and Surface Segregation in High-Voltage Spinel LiMn LiMn 1.5Ni 0.5-xM xO 4(M = Cr, Fe, and Ga) Cathodes for Lithium-Ion Batteries. Chem. Mater. 24, 3720–3731. Figure 1

Optimization of the Chronic Kidney Disease-Peritoneal Dialysis App to Improve Care for Patients on Peritoneal Dialysis in Northeast Thailand: User-Centered Design Study.

BackgroundThe prevalence of peritoneal dialysis (PD) in Thailand is increasing rapidly in part because of Thailand’s Peritoneal Dialysis First policy. PD is a home-based renal replacement therapy in which patients with chronic kidney disease perform up to 4 exchanges of dialysate fluid per day in the peritoneal cavity. Overhydration is one of the most common complications in patients on PD and is associated with increased morbidity and mortality. To monitor hydration status, patients collect hydration metrics, including body weight, blood pressure, urine output, and ultrafiltration volume, from each dialysis cycle and enter this information into a PD logbook. This information is reviewed bimonthly at PD clinic appointments. The chronic kidney disease-PD (CKD-PD) app with near-field communication (NFC) and optical character recognition (OCR) was developed to automate hydration metric collection. The information was displayed in the app for self-monitoring and uploaded to a database for real-time monitoring by the PD clinic staff. Early detection and treatment of overhydration could potentially reduce the morbidity and mortality related to overhydration.ObjectiveThis study aims to identify usability issues and technology adoption barriers for the CKD-PD app with NFC and OCR and a monitoring system and to use this information to make rapid cycle improvements.MethodsA multidisciplinary team of nephrologists, PD clinic nurses, computer programmers, and engineers trained and observed 2 groups of 5 participants in the use of the CKD-PD app with NFC and OCR and a monitoring system. The participants were observed using technology in their homes in 3 phases. The data collected included the Unified Theory of Acceptance and Use of Technology questionnaire, think-aloud observation, user ratings, completion of hydration metrics, and upload of hydration metrics to the central database. These results were used by the team between phases to improve the functionality and usefulness of the app.ResultsThe CKD-PD app with NFC and OCR and a monitoring system underwent 3 rapid improvement cycles. Issues were identified regarding the usability of the NFC and OCR data collection, app stability, user interface, hydration metric calculation, and display. NFC and OCR improved hydration metric capture; however, issues remained with their usability. App stability and user interface issues were corrected, and hydration metrics were successfully uploaded by the end of phase 3. Participants’ scores on technology adoption decreased but were still high, and there was enthusiasm for the self-monitoring and clinical communication features.ConclusionsOur rapid cycle process improvement methodology identified and resolved key barriers and usability issues for the CKD-PD app with NFC and OCR and a monitoring system. We believe that this methodology can be accomplished with limited training in data collection, statistical analysis, and funding.

Surface‐to‐Bulk Synergistic Modification of Single Crystal Cathode Enables Stable Cycling of Sulfide‐Based All‐Solid‐State Batteries at 4.4 V

AbstractThe interfacial stability between sulfide solid‐state electrolytes (SSEs) and high voltage Ni‐rich oxide cathodes is critical to the electrochemical performances of all‐solid‐state batteries (ASSBs), yet it is challenging to solve the interface issues by surface coating modification. Here, a surface‐to‐bulk synergistic modification is proposed to achieve a highly stable interface through the combination of TiNb2O7‐coated and Ti‐doped LiNi0.6Mn0.2Co0.2O2 single crystals (DC‐TNO@SCNCM). The TiNb2O7 coating layer with thermodynamic/electrochemical stability and electronic insulation avoids the decomposition of SSEs. The strong TiO bond in SCNCM achieved by Ti doping can stabilize lattice oxygen and avoid further electrochemically oxidizing sulfide electrolytes to form oxygenated sulfurous and phosphorous species. The modified DC‐TNO@SCNCM cathode exhibits excellent long‐cycle stability with a capacity retention rate of 92.2% after 140 cycles at a high cut‐off voltage of 4.4 V. This surface‐to‐bulk synergistic modification strategy provides a new perspective for the design of high‐voltage sulfide‐based ASSBs.

Interface science in polymer‐based composite solid electrolytes in lithium metal batteries

AbstractSolid‐state lithium metal batteries (SSLMBs) have attracted considerable attention as one of the most promising energy storage systems owing to their high safety and energy density. Solid electrolytes, particularly polymer‐based composite solid electrolytes (CSEs), are considered promising electrolyte candidates for SSLMBs. However, their wide application is inhibited by various electrochemical issues, such as low ionic conductivity, the growth of lithium dendrites, and poor cycling stability, which are related to interface issues within SSLMBs. In this review, the parameters related to various interfaces in the CSE of SSLMBs, including the interfaces between the polymer matrix and inorganic fillers, between the CSEs and the cathode, and between the CSEs and the lithium metal anode, are examined. Relevant issues and corresponding remediation strategies are proposed. Finally, future perspectives based on interfacial engineering and the characterization of polymer/inorganic filler interactions are proposed for building high‐performance CSEs for use in SSLMBs.

Clinical Accuracy of Instrument-Read SARS-CoV-2 Antigen Rapid Diagnostic Tests (Ag-IRRDTs).

This systematic review (PROSPERO registration number: CRD42021282476) aims to collect and analyse current evidence on real-world performance based on clinical accuracy of instrument-read rapid antigen diagnostic tests (Ag-IRRDTs) for SARS-CoV-2 identification. We used PRISMA Checklist and searched databases (PubMed, Web of Science Core Collection and FIND) for publications evaluating the accuracy of SARS-CoV-2 Ag-IRRDTs as of 30 September 2021, and included 40 independent clinical studies resulting in 48 Ag-IRRDT datasets with 137,770 samples. Across all datasets, pooled Ag-IRRDT sensitivity was 67.1% (95% CI: 65.9%–68.3%) and specificity was 99.4% with a tight CI. Pooled sensitivity and specificity of SARS-CoV-2 Ag-IRRDTs did not demonstrate a significant superiority over SARS-CoV-2 rapid antigen tests which do not require a reader instrument, even in the case where surveillance and screening datasets were excluded from the analysis. Nevertheless, they provide connectivity advantages and remove operator interface (in results-reading) issues. The lower sensitivity of certain brands of Ag-IRRDTs can be overcome in high prevalence areas with high frequency of testing. New SARS-CoV-2 variants are major concern for current and future diagnostic performance of these tests.

ESJCEM-(AN ONLINE E-LEARNING AND EXAM PLATFORM)

E-Learning plays a very vital role when it comes to smart education. Though there are many tools for e- learning purpose where, it faces some limitations weather it would be simple user interface or design issues etc. The term e-learning purely defines software development tool which purely rely on software aspects. Remote based learning is the future of next generation where fast learning methodologies would be adapted. The proposed system of e-learning is flourished with Open-source Software and programming tools and database models. Several programming languages are used for Front-end and Back-end in order to make a resplendent user interface. Key Words: Online Learning, Smooth User Interface, Software programming tools, computer vision.

Insights on Shear Transfer Efficiency in "Brick-and-Mortar" Composites Made of 2D Carbon Nanoparticles.

Achieving high mechanical performances in nanocomposites reinforced with lamellar fillers has been a great challenge in the last decade. Many efforts have been made to fabricate synthetic materials whose properties resemble those of the reinforcement. To achieve this, special architectures have been considered mimicking existing materials, such as nacre. However, achieving the desired performances is challenging since the mechanical response of the material is influenced by many factors, such as the filler content, the matrix molecular mobility and the compatibility between the two phases. Most importantly, the properties of a macroscopic bulk material strongly depend on the interaction at atomic levels and on their synergetic effect. In particular, the formation of highly-ordered brick-and-mortar structures depends on the interaction forces between the two phases. Consequently, poor mechanical performances of the material are associated with interface issues and low stress transfer from the matrix to the nanoparticles. Therefore, improvement of the interface at the chemical level enhances the mechanical response of the material. The purpose of this review is to give insight into the stress transfer mechanism in high filler content composites reinforced with 2D carbon nanoparticles and to describe the parameters that influence the efficiency of stress transfer and the strategies to improve it.

Value Of Blood Volume Analysis In Patients With Left Ventricular Assist Devices.

Introduction Implantable left ventricular assist devices (LVAD) have dramatically changed the face of mechanical circulatory support of patients with advanced heart failure. With increased durability, reliability and safety these devices have extended the horizon of functional improvement, life quality and survival. Beyond crucial pre-operative and intra-operative issues, several device-host interface issues are important for successful outcomes. Among these are clear understanding of intravascular volume status, red blood cell volume status. Blood volume analysis (BVA) is a blood test that measures these 3 metrics using the indicator dilution technique, with rapid personalized and actionable results. We used BVA to evaluate 10 consecutive stable ambulatory patients supported with LVAD. Results The patients were seven men and three woman aged 32-70 years. Duration of LVAD support at the time of outpatient BVA (Daxor, Oak Ridge, TN) ranged from 46-1460 days. Two out of eight patients had LVAD (HM3(5), HW(4), HM2(1)implanted as bridge to transplant, all others as destination therapy. Eight out of ten patients were obese with deviations from normal body weight of 22-117% and average BMI of 32.6. All patients were felt to be improved and stable compared to pre-LVAD (INTERMACS 1-3) and none had evidence of device malfunction or drive line infection. All patients had variations in total blood volumes, plasma volume and red cell volume (Table1). Only two out of ten patients had all three BVA parameters within normal limits. Half of the patients had significant hypervolemia, which was not suspected on physical exam. Two out of ten patients had significant hypervolemia with polycythemia, which was not clinically suspected. Conclusions In summary, BVA and its individualized, unique metrics is a valuable test when used in patients with LVAD's. Despite improved functional status and adequate device performance wide variations are still present in patients being supported with LVAD's. Additionally, measurement of red blood cell volume is helpful in determined variations (anemia or polycythemia) that might not be noted clinically and might presage future hemolytic and/or thrombotic events despite adequate anticoagulation. Implantable left ventricular assist devices (LVAD) have dramatically changed the face of mechanical circulatory support of patients with advanced heart failure. With increased durability, reliability and safety these devices have extended the horizon of functional improvement, life quality and survival. Beyond crucial pre-operative and intra-operative issues, several device-host interface issues are important for successful outcomes. Among these are clear understanding of intravascular volume status, red blood cell volume status. Blood volume analysis (BVA) is a blood test that measures these 3 metrics using the indicator dilution technique, with rapid personalized and actionable results. We used BVA to evaluate 10 consecutive stable ambulatory patients supported with LVAD. The patients were seven men and three woman aged 32-70 years. Duration of LVAD support at the time of outpatient BVA (Daxor, Oak Ridge, TN) ranged from 46-1460 days. Two out of eight patients had LVAD (HM3(5), HW(4), HM2(1)implanted as bridge to transplant, all others as destination therapy. Eight out of ten patients were obese with deviations from normal body weight of 22-117% and average BMI of 32.6. All patients were felt to be improved and stable compared to pre-LVAD (INTERMACS 1-3) and none had evidence of device malfunction or drive line infection. All patients had variations in total blood volumes, plasma volume and red cell volume (Table1). Only two out of ten patients had all three BVA parameters within normal limits. Half of the patients had significant hypervolemia, which was not suspected on physical exam. Two out of ten patients had significant hypervolemia with polycythemia, which was not clinically suspected. In summary, BVA and its individualized, unique metrics is a valuable test when used in patients with LVAD's. Despite improved functional status and adequate device performance wide variations are still present in patients being supported with LVAD's. Additionally, measurement of red blood cell volume is helpful in determined variations (anemia or polycythemia) that might not be noted clinically and might presage future hemolytic and/or thrombotic events despite adequate anticoagulation.

Enabling Stable Interphases via In Situ Two-Step Synthetic Bilayer Polymer Electrolyte for Solid-State Lithium Metal Batteries

Poly(ethylene oxide) (PEO)-based electrolyte is considered to be one of the most promising polymer electrolytes for lithium metal batteries. However, a narrow electrochemical stability window and poor compatibility at electrode-electrolyte interfaces restrict the applications of PEO-based electrolyte. An in situ synthetic double-layer polymer electrolyte (DLPE) with polyacrylonitrile (PAN) layer and PEO layer was designed to achieve a stable interface and application in high-energy-density batteries. In this special design, the hydroxy group of PEO-SPE can form an O-H---N hydrogen bond with the cyano group in PAN-SPE, which connects the two layers of DLPE at a microscopic chemical level. A special Li+ conducting mechanism in DLPE provides a uniform Li+ flux and fast Li+ conduction, which achieves a stable electrolyte/electrode interface.LiFePO4/DLPE/Li battery shows superior cycling stability, and the coulombic efficiency remains 99.5% at 0.2 C. Meanwhile, LiNi0.6Co0.2Mn0.2O2/DLPE/Li battery shows high specific discharge capacity of 176.0 mAh g−1 at 0.1 C between 2.8 V to 4.3 V, and the coulombic efficiency remains 95% after 100 cycles. This in situ synthetic strategy represents a big step forward in addressing the interface issues and boosting the development of high-energy-density lithium-metal batteries.

Laplace-Fourier transform solution to the electrochemical kinetics of a symmetric lithium cell affected by interface conformity

Lithium (Li)-metal batteries using solid-state electrolytes (SSEs) have attracted extensive attention owing to their high energy density. However, the interface issues arising from the Li stripping/plating cycles pose a major challenge for the applications of these batteries. This paper reports a three-dimensional (3D) time-dependent electrokinetic model, built based on the Nernst–Planck equation with electroneutrality assumption, to quantify the effects of interface conformity, external pressure, electrolyte Young's modulus, and ionic conductivity on the electrochemical behaviors of symmetric solid-state lithium cells. The evolution of interface morphology is related to the surface roughness, elastoplastic deformation, creep, and plating of the Li metal. The Laplace-Fourier domain solution is analytically derived, and the numerical solution is solved by implementing Talbot's Laplace transform method and the continuous convolution-Fourier transform (CC-FT) algorithm. A number of cases are analyzed, and the results reveal that a non-conformal interface with imperfect contact can induce uneven field distributions and that the nonuniformity increases with contact loss, and that the impact of external pressure on the reduction in ionic conductivity of SSE is similar to its effect on the potential drop. The results also suggest that the external pressure of 12.5 MPa can lead to relatively uniform deposition in a ceramic electrolyte system, while only 2 MPa is required in a polymer electrolyte system. In addition, A pressure of at least 2 MPa is needed to maintain the high ionic conductivity level for polymer composite SSEs of 14–16% volume LLZO particles.

LiF involved interphase layer enabling thousand cycles of LAGP-based solid-state Li metal batteries with 80% capacity retention

The interface compatibility lies in the heart of present investigations on solid-state batteries, now facing significant challenges in practical use. The non-coherent interface structure with the underlying complex electrochemical processes evolves dynamically to pregnant the unfriend seeds to degrade the battery performance. Therefore, interface engineering (or control) in solid-state batteries gives birth to a new theme as ‘the interface is equal to the battery’. In this context, a facile but robust technique is proposed here by smoothing the Li1.5Al0.5Ge1.5P3O12 (LAGP) ceramic pellet with a mirror-like surface, which is found operational in running a solid battery in unprecedentedly a thousand cycles with capacity retention of 80% at 0.5C, 50 °C. Such an unconventional operation is, as a matter of fact, largely decreasing the physically interface contact but proved powerful in guiding the Li-ion homogeneous deposition. Moreover, the self-generated LiF involved interphase layer works efficiently to dynamically balance structural and electrochemical stabilities, where the LiF is introduced by the in-situ polymerization of tiny liquid electrolytes. Hence, the profound results draw the incompatible interface issues forth to the component adjustment of interphases, namely in search for rational descriptions to connect the solid-state electrolyte and electrodes, which probably holds the key to unlocking the high energy density solid-state batteries.