Low Ion Research Articles

Compositional Metrics of Fast and Slow Alfvénic Solar Wind Emerging from Coronal Holes and Their Boundaries

We seek to understand the composition and variability of fast solar wind (FSW) and slow Alfvénic solar wind emerging from coronal holes (CHs). We leverage an opportune conjunction between Solar Orbiter and Parker Solar Probe (PSP) during PSP Encounter 11 to include compositional diagnostics from the Solar Orbiter Heavy Ion Sensor as these variations provide crucial insights into the origin and nature of the solar wind. We use potential field source surface and magnetohydrodynamic models to connect the observed plasma at PSP and Solar Orbiter to its origin footpoint in the photosphere and compare these results with the in situ measurements. A very clear signature of a heliospheric current sheet crossing as evidenced by enhancements in low first ionization potential (FIP) elements, ion charge state ratios, proton density, low Alfvénicity, and polarity estimates validates the combination of modeling, data, and mapping. We identify two FSW streams emerging from small equatorial CHs with low ion charge state ratios, low FIP bias, high Alfvénicity, and low footpoint brightness, yet anomalously low alpha particle abundance for both streams. We identify high-Alfvénicity slow solar wind emerging from the overexpanded boundary of a CH having intermediate alpha abundance, high Alfvénicity, and dips in ion charge state ratios corresponding to CH boundaries. Through this comprehensive analysis, we highlight the power of multi-instrument conjunction studies in assessing the sources of the solar wind.

Enhanced brackish water desalination in capacitive deionization with composite Zn-BTC MOF-incorporated electrodes

In this study, composite electrodes with metal–organic framework (MOF) for brackish water desalination via capacitive deionization (CDI) were developed. The electrodes contained activated carbon (AC), polyvinylidene fluoride (PVDF), and zinc-benzene tricarboxylic acid (Zn-BTC) MOF in varying proportions, improving their electrochemical performance. Among them, the E4 electrode with 6% Zn-BTC MOF exhibited the best performance in terms of CV and EIS analyses, with a specific capacity of 88 F g−1 and low ion charge transfer resistance of 4.9 Ω. The E4 electrode showed a 46.7% increase in specific capacitance compared to the E1 electrode, which did not include the MOF. Physicochemical analyses, including XRD, FTIR, FESEM, BET, EDS, elemental mapping, and contact angle measurements, verified the superior properties of the E4 electrode compared to E1, showcasing successful MOF synthesis, desirable pore size, elemental and particle-size distribution of materials, and the superior hydrophilicity enhancement. By evaluating salt removal capacity (SRC) in various setups using an initially 100.0 mg L−1 NaCl feed solution, the asymmetric arrangement of E1 and E4 electrodes outperformed symmetric arrangements, achieving a 21.1% increase in SRC to 6.3 mg g−1. This study demonstrates the potential of MOF-incorporated electrodes for efficient CDI desalination processes.

Role of ion-beam current and energy for nano-scale joining of copper nanowires: Experimental and theoretical study

Copper nanowires (Cu NWs) are popular potential building blocks of various interconnecting components, microscale circuits, and nanoelectronics. Making interconnects at the nanoscale is still an open problem, and various methods have been explored during the past decades. While ion beam joining has been known for quite some time, the beam parameter-dependent processes leading to joining is yet to be understood in detail. A low-energy (5 keV) and broad argon ion beam is unable to induce joining among the Cu NW mesh, at the low ion currents (<400 nA). However, when the ion current was elevated to 1 µA at the same energy, a large-scale joining was observed. We developed a 3D finite volume model for heat transfer and Joule heating-based melting, which successfully explains the ion current-induced joining. When the current is increased to a significantly high level, the network fragments into smaller copper nanoparticles due to the heat produced. On the other hand, at higher argon ion energy (200 keV) a large-scale joining is observed even at small (<400 nA) beam current. A state-of-the-art, Monte Carlo-based TRI3DYN simulation predicted the role of recoils, redeposition, and ion beam mixing in such joining process at high ion energy, which is mostly due to elastic collisional consequences. Such ion current-induced nanowelded copper mesh-coated PET substrate shows good transmission in the optical range of wavelengths and a notable decrease in the sheet resistance is observed.

Deep Eutectic Solvent‐Based Solid Polymer Electrolytes for High‐Voltage and High‐Safety Lithium Metal Batteries

AbstractSolid‐state electrolytes (SSE) exhibit great promise in enhancing the safety of Li metal batteries by replacing flammable liquid electrolytes. However, the practical application of SSE is hampered mainly due to the poor electrode–electrolyte interface, low ion conductivity, and inferior electrochemical stability. Herein, superior nonflammable solid polymer electrolytes are elaborately designed by in situ encapsulating succinonitrile (SN)‐based deep eutectic solvent (DES) into the ethoxylated trimethylolpropane triacrylate (ETPTA) matrix (DES‐ETPTA). Benefiting from strong polarity and high anti‐oxidation capability, as‐prepared DES‐ETPTA electrolyte shows high ionic conductivity (9.55 × 10−4 S cm−1 at 30 °C), high Li+ transference number (0.68), and good electrochemical stability. As a result, the assembled LiFePO4 || Li full cells based on the designed DES‐ETPTA electrolyte deliver a high reversible capacity and capacity retention at −10 °C and room temperature. Furthermore, considering the compatibility with high‐voltage layered oxide cathode, the electrochemical stability of the ETPTA is further improved through the decoration of cyanoacrylate (CA) with strong electron‐withdrawing characteristic of C≡N. Consequently, the constructed 4.5 V LiCoO2 || Li full cells using DES‐ETPTA‐CA electrolyte deliver a high reversible capacity of 144 mAh g−1 and a superior retention rate of 93% after 200 cycles at 0.5 C. This work paves a new pathway to design high‐safety and high‐voltage solid polymer electrolytes for lithium metal batteries.

Physico-chemical characterization of acid base disorders in patients with COVID-19: A cohort study

BACKGROUND Acid-base imbalance has been poorly described in patients with coronavirus disease 2019 (COVID-19). Study by the quantitative acid-base approach may be able to account for minor changes in ion distribution that may have been overlooked using traditional acid-base analysis techniques. In a cohort of critically ill COVID-19 patients, we looked for an association between metabolic acidosis surrogates and worse clinical outcomes, such as mortality, renal dialysis, and length of hospital stay. AIM To describe the acid-base disorders of critically ill COVID-19 patients using Stewart’s approach, associating its variables with poor outcomes. METHODS This study pertained to a retrospective cohort comprised of adult patients who experienced an intensive care unit stay exceeding 4 days and who were diagnosed with severe acute respiratory syndrome coronavirus 2 infection through a positive polymerase chain reaction analysis of a nasal swab and typical pulmonary involvement observed in chest computed tomography scan. Laboratory and clinical data were obtained from electronic records. Categorical variables were compared using Fisher’s exact test. Continuous data were presented as median and interquartile range. The Mann-Whitney U test was used for comparisons. RESULTS In total, 211 patients were analyzed. The mortality rate was 13.7%. Overall, 149 patients (70.6%) presented with alkalosis, 28 patients (13.3%) had acidosis, and the remaining 34 patients (16.2%) had a normal arterial pondus hydrogenii. Of those presenting with acidosis, most had a low apparent strong ion difference (SID) (20 patients, 9.5%). Within the group with alkalosis, 128 patients (61.0%) had respiratory origin. The non-survivors were older, had more comorbidities, and had higher Charlson’s and simplified acute physiology score 3. We did not find severe acid-base imbalance in this population. The analyzed Stewart’s variables (effective SID, apparent SID, and strong ion gap and the effect of albumin, lactate, phosphorus, and chloride) were not different between the groups. CONCLUSION Alkalemia is prevalent in COVID-19 patients. Although we did not find an association between acid-base variables and mortality, the use of Stewart’s methodology may provide insights into this severe disease.

Detection of dual-methylated BRCA1/BRCA2 cell-free DNA for ovarian cancer on an aptamer-based integrated microfluidic system

A new screening strategy has been developed to select nucleic acid aptamer probes with an “in vivo-like” systematic evolution of ligands by exponential enrichment (SELEX) process featuring positive, negative selection and in vivo-like selection steps. One methylation-specific aptamer with high affinity and specificity was selected and it could capture methylated cell-free DNA (cfDNA) from unfiltered blood of ovarian cancer (OvCa) patients. This aptamer was conjugated onto magnetic beads and integrated into a new microfluidic chip for rapid and automatic detection and quantification of two prevalent methylated tumor suppressor genes, breast cancer type 1 and 2 susceptibility protein (BRCA 1/2), in the molecular profile of OvCa. The assay was conducted under physiological conditions that mimic the microenvironment of cancer patients at 25–37 °C, with a low pH value (5.5) and/or high blood ion levels, without requiring additional sample preparation steps. The results of this study could be extrapolated to the direct detection of methylated cfDNA at levels as low as 1 pM in blood or plasma. Not only was DNA methylation observed in OvCa patients, but it was also detected in many other types of cancer; it is therefore considered an important factor in carcinogenesis. Hence, it is inferred that this screened aptamer should not only be used for OvCa diagnosis but also for multiple cancer epigenetic detection and drug development research in the future.

Unveiling the barriers of Cd translocation from soil to rice: Insights from continuous flooding

Understanding the spatiotemporal processes governing Cd behavior at the soil-solution-root interface is crucial for developing effective remediation strategies. This study examined the processes of chemical remediation in Cd-contaminated paddy soil using rhizotrons over the entire rice growth period. One-dimensional profile sampling with a 10 cm resolution revealed that during the initial flooding, paddy soil was strongly stimulated, followed by stabilization of porewater properties. X-ray diffraction of freeze-dried porewater confirmed the generation of submicron-precipitates such as CdS under continuous flooding, resulting in low ion levels of water-soluble Cd (<1 μg/L) and sulfate (<10 mg/L) in porewater. Two-dimensional imaging technologies indicated the maximum iron‑manganese plaque (IP) within 20–110 μm of the root surface. Subsequently, monitoring O2 in the rhizosphere with a planar optode by two 100 cm2 membranes for a consecutive month revealed significant circadian O2 variations between the root base and tip. Destructive sampling results showed that acid-soluble Cd in soils, as available Cd, is crucial for Cd uptake by rice roots under continuous flooding. The IP deposited on the root surface, as the barriers of Cd translocation, increased with rice growth and blocked Cd translocation from soil to rice by about 18.11 %–25.43 % at maturity. A Si-Ca-Mg compound amendment reduced available Cd by about 10 % and improved Cd blocking efficiency by about 7.32 % through increasing IP concentration, resulting in the absorption ratio of Cd in the amendment group being half that of the control group. By unveiling the complex Cd interactions at the soil-rice interface, this study lays the groundwork for developing effective agricultural practices to mitigate Cd-contaminated paddy and ensure food safety.

Aluminum vacancy‐rich MOF‐derived carbon nanosheets for high‐capacity and long‐life aqueous aluminum‐ion battery

AbstractEco‐friendly and safe aqueous aluminum‐ion batteries as energy storage devices with low economic burden, high stability and fast ion transport have been lucubrated deeply in response to the call for sustainable development. However, the poor cycle performance caused by difficult (de‐)intercalation hinders the development prospect. In this work, the aluminum vacancy‐rich MOF‐derived carbon is constructed to achieve reversible aluminum storage during the charge‐discharge cycles. The MOF‐derived carbon with anti‐stacking waxberry‐like structure exhibits high capacity (282.1 mAh g−1 at 50 mA g−1) and long cycle performance (84.4% capacity retention rate at 1 A g−1 after 5000 cycles). Further investigations demonstrate that (de‐)intercalation occurs among the vacancies of carbon nanosheets in the form of hydrated aluminum ions. Meanwhile, the introduced nitrogen as energy storage sites contributes part of the capacity. The proposed aluminum vacancy engineering improves the current situation of the capacitive energy storage mode for 2D carbon materials, which may exploit an advanced theoretical model for the design of aqueous batteries.

Precisely Prelithiated Polyacrylic Acid Binder Improving Electrochemical Performance of Micron‐Sized Silicon Anodes for Lithium‐Ion Batteries

AbstractSilicon, serving as an anode material of Li‐ion batteries, offers a theoretical capacity significantly higher than graphite, but its practical application is hindered by poor conductivity, low lithium ion diffusivity, and severe volumetric expansion. Here, a simple and eco‐friendly methodology is proposed to synthesize precisely prelithiated polyacrylic acid binder, optimizing the interface between the binder and micron Si particles. The incorporation of these binders not only mitigates the detrimental effects of volumetric expansion but also enhances mechanical strength, and ionic conductivity of the anode, significantly improving the initial Coulombic efficiency (ICE), cycling stability, and rate performance of micron‐sized Si anodes. This study not only highlights the potential of prelithiated binders in overcoming the limitations of micron‐sized Si anodes but also sets a new benchmark for the development of high‐capacity, eco‐friendly Li‐ion batteries.

Self‐Supporting Solid Electrolyte Based on Supramolecular Interaction for Stable Li Metal Batteries

AbstractLi metal batteries based on solid polymer electrolytes offer the benefits of high energy density and safety, as well as extended cycling life, making them an excellent candidate for the next‐generation battery system. However, current solid polymer electrolytes still suffer from low ion conductivity and Li+ transfer number, which seriously restricts its practical application. Herein, a self‐supporting composite solid polymer electrolyte was prepared, where phenolic resin rich in hydroxyl groups (BR) and polyethylene oxide (PEO) are mixed evenly and poured onto a cellulose membrane in one step. In such an electrolyte, PEO and BR combine to form intermolecular hydrogen bonds, lowering the crystallinity of PEO and increasing the Li+ transfer number. Lastly, the obtained solid electrolytes exhibited a high ion conductivity (1.1×10−4 S cm−1) and Li+ transfer number (0.53), as well as improved electrochemical window. Consequently, Li || Li symmetrical cells can run stably for more than 700 h at 0.1 mA cm−2/0.25 mAh cm−2. And full cells with LiFePO4 cathode can also demonstrate high discharge capacity of 152.12 mAh g−1 and rate performance. We believe that such a design based on supramolecular interaction offer a new avenue to advanced solid polymer electrolytes.

Ca-Doping Cobalt-Free Double Perovskite Oxide as a Cathode Material for Intermediate-Temperature Solid Oxide Fuel Cell.

Mixed oxygen ion and electron-conducting materials are viable cathodes for solid oxide fuel cells due to their excellent oxygen transport kinetics and mixed electrical conductivity, which ensure highly efficient operation at low and medium temperatures. However, iron-based double perovskite oxides usually exhibit poor electrocatalytic activity due to low electron and oxygen ion conductivity. In this paper, Ca is doped in PrBaFe2O5+δ A-site to improve the electrochemical performance of PrBaFe2O5+δ. Results show that replacing Pr with Ca does not change the crystal structure, and the Ca doping effectively increases the adsorbed oxygen content and accelerates the migration and diffusion rate of O2- to the electrolyte|cathode interface. The polarization resistance of the symmetric cell PC0.15BF|CGO|PC0.15BF is 0.033 Ω·cm2 at 800 °C, which is about 56% lower than that of PBF, confirming the enhancement of the mixed conduction of oxygen ions and electrons. In addition, the anode-supported single cell has a peak power density of 512 mW·cm-2 at 800 °C.

Dual functional composite solid electrolyte constructed by double-layer sulfonated polyethersulfone (SPES)/poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membrane in high-performance all-solid-state lithium metal batteries

The successful implementation of polymer electrolytes in next-generation all-solid-state lithium metal batteries (ASSLMBs) is impeded by their low ion conductivity and weak resistance to lithium dendrites. Herein, a composite solid electrolyte (D-SPES-PH-PEO) with dual reinforcement effects is obtained by combining PEO matrix with a double-layer sulfonated polyethersulfone (SPES)-poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membrane. The SPES nanofiber membrane acts as a hopping site for ion transport by utilizing the electronegativity and Coulombic force of its own –SO3H groups, reducing the energy barrier of the D-SPES-PH-PEO electrolyte. Profiting from the existence of C-F bond, PVDF-HFP nanofiber membrane specializes in generating a protective SEI layer on the lithium anode. Moreover, such a functional membrane not only effectually constructs a three-dimensional ion transport channel by fabricating ion conductive substructures, but also enhances the mechanical strength of the electrolyte. Consequently, the D-SPES-PH-PEO electrolyte is equipped with a high ion conductivity of 7.41 × 10−5 S cm−1 at 30 °C and high tensile strength of 8 MPa. Furthermore, Li/Li symmetric battery incorporating D-SPES-PH-PEO electrolyte enables a stable cycle for 2500 h at 0.2 mAh cm−2. The D-SPES-PH-PEO electrolyte represents outstanding compatibility with LiFePO4 and high-voltage LiNi0.8Mn0.1Co0.1O2 (NMC811) electrodes. Especially, the LiFePO4/D-SPES-PH-PEO/Li pouch cell indicates an initial specific capacity of 146.7 mAh g−1 and the NMC811/D-SPES-PH-PEO/Li pouch cell reaches a maximum capacity of 178.5 mAh g−1. This study emphasizes the importance of double reinforcement of ion conduction and anode protection on solid electrolytes.

Dumbbell-Shaped, Block-Graft Copolymer with Aligned Domains for High-Performance Hydrocarbon Polymer Electrolyte Membranes.

Given the environmental concerns surrounding fluoromaterials, the use of high-cost perfluorinated sulfonic acids (PFSAs) in fuel cells and water electrolysis contradicts the pursuit of clean energy systems. Herein, we present a fluorine-free dumbbell-shaped block-graft copolymer, derived from the cost-effective triblock copolymer, poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS), for polymer electrolyte membranes (PEMs). This unique polymer shape led to the alignment of the hydrophobic-hydrophilic domains along a preferred orientation, resulting in the construction of interconnected proton channels across the membrane. A bicontinuous network allowed efficient proton transport with reduced tortuosity, leading to an exceptional ionic conductivity (249 mS cm-1 at 80 °C and 90 % relative humidity (RH)), despite a low ion exchange capacity (IEC; 1.41). Furthermore, membrane electrode assembly (MEA) prepared with our membrane exhibited stable performance over a period of 150 h at 80 °C and 30 % RH. This study demonstrates a novel polymer structure design and highlights a promising outlook for hydrocarbon PEMs as alternatives to PFSAs.

Dumbbell‐Shaped, Block‐Graft Copolymer with Aligned Domains for High‐Performance Hydrocarbon Polymer Electrolyte Membranes

AbstractGiven the environmental concerns surrounding fluoromaterials, the use of high‐cost perfluorinated sulfonic acids (PFSAs) in fuel cells and water electrolysis contradicts the pursuit of clean energy systems. Herein, we present a fluorine‐free dumbbell‐shaped block‐graft copolymer, derived from the cost‐effective triblock copolymer, poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) (SEBS), for polymer electrolyte membranes (PEMs). This unique polymer shape led to the alignment of the hydrophobic‐hydrophilic domains along a preferred orientation, resulting in the construction of interconnected proton channels across the membrane. A bicontinuous network allowed efficient proton transport with reduced tortuosity, leading to an exceptional ionic conductivity (249 mS cm−1 at 80 °C and 90 % relative humidity (RH)), despite a low ion exchange capacity (IEC; 1.41). Furthermore, membrane electrode assembly (MEA) prepared with our membrane exhibited stable performance over a period of 150 h at 80 °C and 30 % RH. This study demonstrates a novel polymer structure design and highlights a promising outlook for hydrocarbon PEMs as alternatives to PFSAs.

Interfacial Super‐Assembly of Vacancy Engineered Ultrathin‐Nanosheets Toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion

AbstractIon‐selective nanochannel membranes assembled from two‐dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy‐engineered, oxygen‐deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers‐wrapped carbon nanotubes (VOLDH/CNF‐CNT) composite membrane. This membrane, featuring abundant angstrom‐scale, cation‐selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super‐assembly. The composite membrane shows interlayer free‐spacing of ~3.62 Å, which validates the membrane size exclusion selectivity. This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high‐power density of 5.35 W/m2 with long‐term durability (20,000s), which is almost 400 % higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH‐ and temperature‐sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high‐performance salinity gradient power conversion and underscores the potential of vacancy engineering and super‐assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

Interfacial Super-Assembly of Vacancy Engineered Ultrathin-Nanosheets Toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion.

Ion-selective nanochannel membranes assembled from two-dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy-engineered, oxygen-deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers-wrapped carbon nanotubes (VOLDH/CNF-CNT) composite membrane. This membrane, featuring abundant angstrom-scale, cation-selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super-assembly. The composite membrane shows interlayer free-spacing of ~3.62 Å, which validates the membrane size exclusion selectivity. This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high-power density of 5.35 W/m2 with long-term durability (20,000s), which is almost 400 % higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH- and temperature-sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high-performance salinity gradient power conversion and underscores the potential of vacancy engineering and super-assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

Fabrication of high aspect ratio AlN nanopillars by top-down approach combining plasma etching and wet etching

This study proposes a top-down approach for fabricating high aspect ratio AlN pillars with m-oriented nonpolar sidewalls, which will serve as the first building block for the fabrication of core-shell UV-LEDs. Such structures are achieved through a two-step process, combining a chlorine plasma etching, followed by a wet chemical etching with KOH. In this work, the mechanisms driving the AlN etching in chlorine plasma are discussed. In particular, we highlight the impact of the ratio between ion flux and radical flux on AlN etch rates, pillar profiles, and crystal orientation-dependent etching. We also identify two mechanisms of passivation layer formation on the pillar sidewalls that contribute to the pattern slope: redeposition of the carrier wafer etch by-products and Aluminium line of sight redeposition, both phenomena are also driven by the ionic bombardment. Low ionic bombardment (either low ion over radical flux ratio or low ion energy) has been identified as plasma conditions allowing the patterning of anisotropic AlN pillars but with the formation of a-nonpolar facets. Due to the inability to obtain m-oriented sidewalls using Cl2 plasma etching alone, we show that the use of a KOH wet etching treatment allows verticalizing the pillars and revealing smooth m-facets on the pillars’ sidewalls if suitable m-oriented hard mask is used. In this wet etching step, we highlight the key role played by the hard mask and its initial shape during the wet etching if straight and m-oriented pillars are desired.

Boosted Li+ transport ensured by high-entropy Prussian blue analogues with tuned PF6− adsorption for stable Li metal anode

The inhomogeneous lithium metal (Li) deposition and low lithium ion (Li+) mobility lead to the formation and growth of Li dendrites, which impede the desirable performance of Li metal batteries (LMBs) with high energy density in widely practical applications. Herein, a high-entropy MnCoNiCuZn-Prussian blue analogue (HE-PBA) is utilized to modify the commercial polypropylene separator (PP@HE-PBA), which will form an artificial protective layer on the surface of Li. The polar –CN groups of HE-PBA can enhance the wettability of PP to the electrolyte, while the movement of PF6− anions are flexibly tuned by the appropriate absorption ability and synergistic effect of multiple metal ions in HE-PBA. A high Li+ transference number of 0.69 is achieved, which can relieve the Li+ concentration polarization, regulate the Li+ flow, and realize the uniform Li deposition. With PP@HE-PBA, the Li||Li symmetric cells display durability up to 600 h in the ester-based electrolyte at 1 mA cm−2 for 1 mAh cm−2. Also, the PP@HE-PBA exhibits great potential in LMBs, where the Li4Ti5O12 (LTO) ||Li and sulfated polyacrylonitrile (S-PAN) ||Li batteries deliver superior cycling performance to those without PP@HE-PBA.

A universal pre-charging method for enhancing transient speed in Organic Electrochemical Transistors

Organic electrochemical transistors (OECT) have shown great potential in diverse applications; however, in many OECTs, their slow transient response has thus far limited their practical use. One reason for the slow response is the complex interplay between lateral and vertical ion transport that has so far been poorly understood. In this work, we study the impact of lateral ion transport on OECT transient response, introduce a robust pre-charging method to manipulate the slow lateral ion transport. This approach leads to quicker ion redistribution and improved switching speeds. We show the general utility of pre-charging method in enhancing the switching speeds across various material systems, characterized by both low and high ion mobilities, and across different device architectures, achieving nearly symmetric speeds for both on-switching and off-switching. Moreover, we showcase the efficacy of the pre-charging method in enabling slow OECTs to capture rapid signals in real-world applications. Our findings present a groundbreaking strategy for enhancing the response times of OECT devices and deepening our understanding of the transient mechanisms in OECT device.

Prospects and Strategies for Single‐Crystal NCM Materials to Solve All‐Solid‐State Battery Cathode Interface Problems

AbstractIn the ongoing quest to develop lithium‐ion batteries with superior capacity and enhanced safety, the focus has shifted toward all‐solid‐state batteries (SSBs) and nickel‐rich cathode materials. Despite their promise, these technologies face significant interface challenges, notably poor contact and low ion transport efficiency, leading to substantial stability issues. This review aims to provide a comprehensive analysis of both the advantages and the challenges associated with all‐solid‐state batteries. In addition, it discusses the benefits of single‐crystal application in SSBs, in terms of their kinetic performance, mechanical properties, and stability. The review concludes by proposing various strategies to optimize single‐crystal technologies, targeting the development of efficient nickel‐rich single‐crystal materials for use in all‐solid‐state batteries. These approaches offer the potential to address the core challenges currently faced by SSBs and pave the way for the next generation of high‐performance batteries.