High Conductivity Research Articles

High ionic conductivity materials Li3YBr6 and Li3LaBr6 for solid-state batteries: first-principles calculations

High ionic conductivity solid-state electrolytes are essential for powerful solid-state lithium-ion batteries. With density functional theory andab initiomolecular dynamics simulations, we investigated the crystal structures of Li3YBr6and Li3LaBr6. The lowest energy configurations with uniform distribution of lithium ions were identified. Both materials have wide electrochemical stability windows (ESW): 2.64 V and 2.57 V, respectively. The experimental ESW for Li3YBr6is 2.50 V. Through extrapolating various temperature diffusion results, the conductivity of Li3YBr6was obtained at room temperature, approximately 3.9 mS cm-1, which is comparable to the experimental value 3.3 mS cm-1. Li3LaBr6has a higher conductivity, a 100% increase compared with Li3YBr6. The activation energies of Li3YBr6and Li3LaBr6through the Arrhenius plot are 0.26 eV and 0.24 eV, respectively, which is also close to the experimental value of 0.30 eV for Li3YBr6. This research explored high ionic conductivity halide materials and will contribute to developing solid-state lithium-ion batteries.

Highly Anisotropic Thermally Conductive Dielectric Polymer/Boron Nitride Nanotube Composites for Directional Heat Dissipation.

An ideal dielectric material for microelectronic devices requires a combination of high anisotropic thermal conductivity and low dielectric constant (ɛ') and loss (tan δ). Polymer composites of boron nitride nanotubes (BNNTs), which offer excellent thermal and dielectric properties, show promise for developing these dielectric polymer composites. Herein, a simple method for fabricating polymer/BNNT composites with high directional thermal conductivity and excellent dielectric properties is presented. The nanocomposites with directionally aligned BNNTs are fabricated through melt-compounding and in situ fibrillation, followed by sintering the fibrous nanocomposites. The fabricated nanocomposites show a significant enhancement in thermal properties, with an in-plane thermal conductivity (K‖) of 1.8 Wm-1K-1-a 450% increase-yielding a high anisotropy ratio (K‖/K⊥) of 36, a 1700% improvement over isotropic samples containing only 7.2 vol% BNNT. These samples exhibit a 120% faster in-plane heat dissipation compared to the through-plane within 2 s. Additionally, they display low ɛ'of ≈3.2 and extremely low tan δ of ≈0.014 at 1kHz. These results indicate that this method provides a new avenue for designing and creating polymer composites with enhanced directional heat dissipation properties along with high K‖, suitable for thermal management applications in electronic packaging, thermal interface materials, and passive cooling systems.

A high-performance watermelon skin ion-solvating membrane for electrochemical CO2 reduction

Ion-solvating membranes have been gaining increasing attention as core components of electrochemical energy conversion and storage devices. However, the development of ion-solvating membranes with low ion resistance and high ion selectivity still poses challenges. In order to propose an effective strategy for high-performance ion-solvating membranes, this study conducted a comprehensive investigation on watermelon skin membranes through a combination of experimental research and molecular dynamics simulation. The micropores and continuous hydrogen-bonding networks constructed by the synergistic effect of cellulose fiber and pectin enable the hypodermis of watermelon skin membranes to have a high ion conductivity of 282.3 mS cm−1 (room temperature, saturated with 1 M KOH). The negatively charged groups and hydroxyl groups on the microporous channels increase the formate penetration resistance of watermelon skin membranes in contrast to commercially available membranes, and this is crucial for CO2 electroreduction. Therefore, the confinement of proton donors and negatively charged groups within three-dimensional microporous polymers gives inspiration for the design of high-performance ion-solvating membranes.

A Redox-Active Iron-Organic Framework Cathodes for Sustainable Magnesium Metal Batteries.

Rechargeable magnesium metal batteries (RMBs) have shown promising prospects in sustainable energy storage due to the high crustal abundance, safety, and potentially large specific capacity of magnesium. However, their development is constrained by the lack of effective cathode materials that can achieve high capacity and stable magnesium storage at a practically reasonable rate. Herein, we construct a three-dimensional (3D) iron(III)-dihydroxy-benzoquinone (Fe2(DHBQ)3) metal-organic framework (MOF) material with dual redox centers of Fe3+ cations and DHBQ2- anions for reversible storage of Mg2+ in RMBs. Spectroscopic analysis and density functional theory (DFT) calculations reveal the redox chemistry of both Fe3+ ions and carbonyls from DHBQ ligands during electrochemical processes. Benefiting from the rational structure, the Fe2(DHBQ)3∥Mg cells exhibit a high reversible capacity of 395.3 mAh/g, large energy density of 463.5 Wh/kg, and high power density of 2456.0 W/kg. Moreover, the high electronic conductivity (8.35 × 10-5 S/cm) and favorable diffusion path of Mg2+ in Fe2(DHBQ)3 endow the cells with exceptional cycling stability and rate capability with a long life of 5000 cycles at 2000 mA/g. The dual redox-active MOF demonstrates a category of advanced cathode materials for high-performance RMBs.

Sn‐Doped Carbon Black as an Active Conductive Additive for Lithium‐Ion Batteries

AbstractCarbon black is commonly used as a conductive additive for lithium‐ion battery (LIB) electrodes owing to its high electrical conductivity and cost‐effectiveness. However, the role of traditional conductive additives has been limited to imparting conductivity to the electrode. In this study, we investigate the effect of incorporating Sn nanoparticles, which form an alloy with lithium, into a conductive carbon matrix (Sn@C) for enhancing the lithium storage capacity. This approach combines an active material with a conductive additive and successfully demonstrates the utilization of Sn@C as an “active” conductive additive for LIBs. Sn@C is synthesized via plasma engineering, wherein Sn nanoparticles are uniformly dispersed within a carbon matrix. When Sn@C‐500, Sn@C annealed at 500 °C, is used as an “active” conductive additive in LIB half‐cell with a graphite anode, ~10 % higher reversible capacity than that of a commercial conductive additive (Super P) is achieved. Further, electrochemical impedance spectroscopy studies reveal that Sn@C‐500 exhibits a lower internal resistance than Super P, confirming its effectivity in providing internal conductivity to the electrode. Our results open up the possibilities for improving the performance of graphite anodes in LIBs using Sn‐doped carbon as an active material and conductive additive.

Hydrophobic Multilayered PEG@PAN/MXene/PVDF@SiO2 Composite Film with Excellent Thermal Management and Electromagnetic Interference Shielding for Electronic Devices.

With the rapid development of electronic industry, it's pressing to develop multifunctional electromagnetic interference (EMI) shielding materials to ensure the stable operation of electronic devices. Herein, multilayered flexible PEG@PAN/MXene (Ti3C2Tx)/PVDF@SiO2 (PMF) composite film has been constructed from the level of microstructure design via coaxial electrospinning, coating spraying, and uniaxial electrospinning strategies. Benefiting from the effective encapsulation for PEG and high conductivity of MXene coating, PEG@PAN/MXene composite film with MXene coating loading density of 0.70mg cm-2 exhibits high thermal energy storage density of 120.77 J g-1 and great EMI shielding performance (EMI SE of 34.409dB and SSE of 49.086dB cm3 g-1) in X-band (8-12GHz). Therefore, this advanced composite film can not only help electronic devices prevent the influence of electromagnetic pollution in the X-band but also play an important role in electronic device thermal management. Additionally, the deposition of nano PVDF@SiO2 fibers (289±128nm) endowed the PMF composite film with great hydrophobic properties (water contact angle of 126.5°) to ensure the stable working of hydrophilic MXene coating, thereby breaks the limitation of humid application environments. The finding paves a new way for the development of novel multifunctional EMI shielding composite films for electronic devices.

Thionation‐Induced Enhancement of Optical and Electronic Properties in NDI Molecule for Molecular Electronic Applications: A Computational Study Using DFT/TD‐DFT and QTAIM Theory

AbstractThe study investigates the impact of thionation on N,N'‐di(dodecyl)‐4,5,8,9‐naphthalene diimide (NDI) through computational methods such as density functional theory (DFT/TD‐DFT), quantum theory of atoms in molecules (QTAIM), and Landauer theory (LT). Thionation, involving the replacement of diamide oxygens with sulfurs in NDI, significantly enhances quantum‐electronic/thermoelectric properties. Computational analyzes of energy of frontier orbitals HOMO/LUMO, dipole moment, polarizability, first superpolarizability, UV spectrum, and cohesive energy show the superior performance of the thione structure (M2) compared to the pristine structure (M1). Thionation decreased the energy gap from 01.3 eV (in M1 structure) to 1.87 eV (in M2 structure). The absorption wavelength in the pristine structure (M1) is calculated to be 507 nm, which increased to 1067 nm after thionation (M2). Cohesive energy values for each of M1 and M2 structures are calculated as 12.76 and 12.89 Kcal mol−1, respectively, which indicates the improvement of stability after thionation. After connecting M1 and M2 to gold electrodes (Au‐M1‐Au and Au‐M2‐Au) and applying electric fields, the Au‐M2‐Au structure shows a lower energy gap, lower thermoelectric activity and higher conductivity at field intensities with higher than 140 × 10−4 (a.u.), indicating its use as a field‐effect molecular device (such as molecular wire or molecular switch).

Tuning the Locally Enhanced Electric Field Treatment (LEEFT) between Electrophysical and Electrochemical Mechanisms for Bacteria Inactivation.

Efficient drinking water disinfection methods are critical for public health. Locally enhanced electric field treatment (LEEFT) is an antimicrobial method that uses sharp structures, like metallic nanowires, to enhance the electric field at tips and cause bacteria inactivation. Electroporation is the originally designed mechanism of LEEFT. Although oxidation is typically undesired due to byproduct generation and electrode corrosion, it can enhance the overall disinfection efficiency. In this work, we conduct an operando investigation of LEEFT, in which we change the electrical parameters to tune the mechanisms between electrophysical electroporation and electrochemical oxidation. Pure electroporation (i.e., without detectable oxidation) could be achieved under a duty cycle of ≤0.1% and a pulse width of ≤2 μs. Applying 2 μs pulses at 7-8 kV/cm and 0.1% duty cycle results in 80-100% bacteria inactivation with pure electroporation. A higher chance of oxidation is found with a higher duty cycle and a longer pulse width, where the antimicrobial efficiency could also be enhanced. For water with a higher conductivity, a higher antimicrobial efficiency can be achieved under the same treatment conditions, and electrochemical reactions could be induced more easily. The findings shown in this work improve the fundamental understanding of LEEFT and help optimize the performance of LEEFT in real applications.

Lignin-Stabilized Tough, Sticky, and Recyclable Liquid Metal/Protein Organogels for Multifunctional Epidermal Smart Materials.

Biomass-encapsulated liquid metals (LMs) composite gels have aroused tremendous attention as epidermal smart materials due to their biocompatibility and sustainability. However, they can still not simultaneously possess toughness, adhesion, and recoverability. In this work, the tough, sticky, and recyclable protein-encapsulated LMs organogels (GLMx) are fabricated through the micro-interfacial stabilization of LMs by lignin and the following preparation of food-making inspired gels. With the help of lignin modification, the LMs micro-drops demonstrated uniform dispersion in the protein matrix, as well as dense non-covalent interactions (e.g., H─bond and hydrophobic interaction) with amino acid residues in peptide chains, which endowed the GLMx with high conductivity (≈5.4Sm-1), toughness (≈738.2kJm-3), self-adhesiveness (a maximal lap-shear strength of ≈58.3kPa), and recoverability. By tightly adhering onto human skin, the GLMx can act as epidermal sensors to detect drastic (e.g., joint bending) and subtle body movements (e.g., swallowing) and even recognize handwriting and speaking in real-time. Moreover, the organogels can also harvest solar energy and convert it into heat and electricity, which is promising in self-powered intelligent devices. Thus, this work paves a facile way to prepare protein/LMs composite organogels that are suitable for multiple applications like healthcare, human-robot interactions, and solar energy conversion.

Fabrication of PHFPO Surface-Modified Conductive AgNWs/PNAGA Hydrogels with Enhanced Water Retention Capacity toward Highly Sensitive Strain Sensors.

Conductive hydrogels, characterized by their unique features of flexibility, biocompatibility, electrical conductivity, and responsiveness to environmental stimuli, have emerged as promising materials for sensitive strain sensors. In this study, a facile strategy to prepare highly conductive hydrogels is reported. Through rational structural and synthetic design, silver nanowires (AgNWs) are incorporated into poly(N-acryloyl glycinamide) (PNAGA) hydrogels, achieving high electrical conductivity (up to 0.88 S m-1), significantly enhanced mechanical properties, and elevated deformative sensitivity. Furthermore, surface modification with polyhexafluoropropylene oxide (PHFPO) has substantially improved the water retention capacity and dressing comfort of this hydrogel material. Based on the above merits, these hydrogels are employed to fabricate highly sensitive wearable strain sensors which can detect and interpret subtle hand and finger movements and enable precise control of machine interfaces. The AgNWs/PNAGA based strain sensors can effectively sense finger motion, enabling the control of robotic fingers to replicate the human hand's gestures. In addition, the high deformative sensitivity and elevated water retention performance of the hydrogels makes them suitable for flow sensing. These conceptual applications demonstrate the potential of this conductive hydrogel in high-performance strain sensors in the future.

Polypyrrole Derivatives: Preparation, Properties and Application

Polypyrrole (PPy) has attracted widespread attention due to its excellent environmental stability, high conductivity, simple synthesis, good biocompatibility, and reversible redox properties. PPy derivatives not only inherit the advantages of polypyrrole, but also have some unique properties. The side and N-site substitution of PPy can not only yield polymers with good solubility, but it also endows polymers with special functionalities by controlling the introduced functional groups. The performance of copolymers can also be adjusted by the type of monomer or polymerization ratio. In this review, an overview of the different types, main preparation methods, and the application prospects of PPy derivatives reported to date are summarized and presented. The current challenges and future opportunities in this research area are also prospected.

Influence of perturbative intertube interactions on ballistic and quasi-ballistic phonon transports in double-walled carbon nanotubes

Assembling single-walled carbon nanotubes (SWCNT) into multiwalled carbon nanotubes (MWCNT) reduces the intrinsically high thermal conductivity of individual SWCNTs. Typically, this reduction can be explained by structural imperfections, e.g., defects, and van der Waals (vdW) intertube interactions between the constituent SWCNTs are considered to have negligible impacts on the reduction. However, intertube interactions should alter the transport characteristics of low-frequency phonons responsible for heat conduction, which implies that intertube interactions may also reduce the thermal conductivity of MWCNTs when low-frequency phonons modulated by intertube interactions participate in the overall heat conduction. In this study, by applying a combination of the atomistic Green's function method and nonequilibrium molecular dynamics simulation to double-walled carbon nanotubes (DWCNT) with different chiral configurations of SWCNTs and various lengths, we investigated the length scale and chiral configuration where perturbative intertube interactions can suppress phonon transports. We found that thermal resistance attributed to intertube interactions manifests in the low-temperature ballistic regime and quasi-ballistic regime for DWCNT lengths greater than 1 μm. Revisiting the influence of the intertube interactions helps comprehend the intrinsic origin of the reduced thermal conductivity of MWCNTs. In addition, the reported findings are beneficial for the thermal engineering of SWCNT-assembled materials, including emerging one-dimensional vdW heterostructures.

Investigation of the impact of environmental conditions on the mechanical properties of thin film copper wafers

Abstract Thin film copper offers excellent film texture for multilevel interconnections in integrated circuits fabrication because of its superior resistivity to electromigration and high electricelectrical conductivity. To perform a semiconductor fabrication of copper during chemical mechanical planarization process, it is necessary to have a thorough understanding of the nanomechanical properties of thin film copper. In this study, thin film copper and reacted passivation layers on silicon substrate wafer are investigated for their nanomechanical properties under various environmental conditions. The results of this study indicate that thin film copper passivation layers have different properties in deionized water and polishing slurry environments compared to thin film copper exposed to ambient air. The insights gained from this study emphasize the significance of considering both the passivation layers and wet environments in semiconductor fabrication processes, contributing to the advancement of copper-based interconnect materials and optimization of the chemical mechanical planarization process in semiconductor manufacturing.

Improved Electrochemical Performance of NASICON Type Na3V2-xCox(PO4)3/C (x = 0-0.15) Cathode for High Rate and Stable Sodium-Ion Batteries.

In recent years, the Na-ion SuperIonic CONductor (NASICON) based polyanionics are considered pertinent cathode materials in sodium-ion batteries due to their 3D open framework, which can accommodate a wide range of Na content and can offer high ionic conductivity with great structural stability. However, owing to the inferior electronic conductivity, these materials suffer from unappealing rate capability and cyclic stability for practical applications. Therefore, in this work we investigate the effect of Co substitution at the V site on the electrochemical performance and diffusion kinetics of Na3V2-xCox(PO4)3/C (x = 0-0.15) cathodes. All the samples are characterized through Rietveld refinement of the X-ray diffraction patterns, Raman spectroscopy, transmission electron microscopy, etc. We demonstrate improved electrochemical performance for the x = 0.05 electrode with a reversible capacity of 105 mAh g-1 at 0.1 C. Interestingly, the specific capacity of 80 mAh g-1 is achieved at 10 C with retention of about 92% after 500 cycles and 79.5% after 1500 cycles and having nearly 100% Coulombic efficiency. The extracted diffusion coefficient values through the galvanostatic intermittent titration technique and cyclic voltammetry are found to be in the range of 10-9 to 10-11 cm2 s-1. The post-mortem studies show excellent structural and morphological stability after testing for 500 cycles at 10 C. Our study reveals the role of optimal dopant of Co3+ ions at the V site in improving the cyclic stability at a high current rate.

Combustion synthesis of tunable‐aspect‐ratio β‐Si3N4/BN composite ceramic materials

AbstractHigh thermally conductive β‐Si3N4 is a new type of filler for thermally conductive materials. Tailoring its aspect ratio is crucial to optimize the preparation process and performance of polymer‐based thermal conductive materials. In this work, β‐Si3N4/BN thermally conductive hybrid fillers were prepared by combustion synthesis in a nitrogen atmosphere using low‐cost Si, B2O3 powders as raw materials, and the aspect ratio of β‐Si3N4 crystals were regulated according to the inhibiting growth strategy of second phase BN generated by in situ reaction. With the increase of B2O3, the content of BN increased slightly, while that of β‐Si3N4 decreased slightly. The aspect ratio of β‐Si3N4 decreased from 6.3 ± 1.9 to 1.9 ± 0.6, which might be ascribed to the inhibiting effect of BN sheets on the axial growth of rod‐like β‐Si3N4. Low‐aspect‐ratio β‐Si3N4/BN/epoxy composite exhibited high thermal conductivity of 1.04 W·m‐1·K‐1at the solid content of 50 wt%, which was 372.7% and 30.0% higher than that of neat epoxy and 40 wt% high‐aspect‐ratio β‐Si3N4/epoxy composite, respectively. In addition, β‐Si3N4/BN/epoxy composite also had good mechanical properties.

Phase and defect structures of MnO2‐doped 75BiFeO3–25BaTiO3 ceramics and their effects on electrical properties

AbstractBismuth ferrite (BiFeO3)‐based high‐temperature piezoelectric ceramics have high Curie temperatures and excellent thermal stability; however, their applications are limited by inadequate piezoelectric performance due to large coercive fields and high leakage conduction. This study investigates the impact of MnO2 doping on the phase transition, defect structure, domain morphology, as well as the dielectric, ferroelectric, and electrical conduction behaviors of 75BiFeO3–25BaTiO3 ceramics sintered under an oxygen atmosphere. A structural transformation from distorted rhombohedral to pseudo‐cubic symmetry was observed with increasing MnO2 content, accompanied by domain fragmentation. MnO2 doping at an appropriate level inhibited defects such as and . Regarding electrical properties, the reduction in rhombohedral distortion and enhancement in the pseudo‐cubic phase after MnO2 doping resulted in decreased remanent polarization and electrostrain, which could potentially hinder piezoelectric response. However, appropriate MnO2 doping effectively reduced leakage conduction, significantly enhancing the poling efficiency of the ceramics. The maximum d33 value of 107 pC/N and kp of 0.36 were achieved at an MnO2 doping content of 0.1 wt.%. Excessive MnO2 addition may generate defect dipoles, as indicated by increased coercive field (Ec) and dielectric loss. The observed increase in high‐temperature resistivity with MnO2 content is primarily attributed to reduced grain size and increased concentration of mobile defects. This study provides valuable insights for further research on the application of 75BiFeO3–25BaTiO3 systems in high‐temperature piezoelectric devices.

A lamellar-morphology-based computational modeling for predicting the thermal conductivity of semicrystalline polymers

Molecular-scale design of crystal structures is an emerging approach for significantly improving the intrinsic properties of polymers. In this study, we performed computational modeling to quantitatively predict the thermal conductivity of polymers based on their crystal morphology. Polyethylene lamellae with alternating crystalline and amorphous phases were prepared using isothermal crystallization within a coarse-grained molecular dynamics framework. The crystalline bulk, transient, and amorphous regions were clearly distinguished based on the distribution of the Steinhardt-bond order parameter. The thermal conductivity of the local regions was estimated discretely by applying a steady heat flow, facilitating a bottom-up prediction of the thermal response depending on the morphology of the lamellae. In particular, the integration with homogenization theory can evaluate the effective thermal conductivity of the system in terms of crystallinity, temperature, lamella thickness and orientation. The modeling successfully provided quantitative predictions for two representative hierarchical structures: spherulites and oriented crystals. Therefore, this study serves as a theoretical guide for molecular-level rational design of semicrystalline materials with high thermal conductivity.

Helical peptide structure improves conductivity and stability of solid electrolytes.

Ion transport is essential to energy storage, cellular signalling and desalination. Polymers have been explored for decades as solid-state electrolytes by either adding salt to polar polymers or tethering ions to the backbone to create less flammable and more robust systems. New design paradigms are needed to advance the performance of solid polymer electrolytes beyond conventional systems. Here the role of a helical secondary structure is shown to greatly enhance the conductivity of solvent-free polymer electrolytes using cationic polypeptides with a mobile anion. Longer helices lead to higher conductivity, and random coil peptides show substantially lower conductivity. The macrodipole of the helix increases with peptide length, leading to larger dielectric constants. The hydrogen bonding of the helix also imparts thermal and electrochemical stability, while allowing for facile dissolution back to monomer in acid. Peptide polymer electrolytes present a promising platform for the design of next-generation ion-transporting materials.

Conductive graphene-based coagulated composites for electronic printing applications

Graphene is gaining significance in applications such as sensors, antennas, photonics and spintronics. In particular, it is suitable for printing components and circuits affording the properties of high conductivity alongside flexibility, elasticity and wearability. For this application, graphene is typically customised into a fluidic form—ink or paint. This paper reports a novel, economical, scalable methodology for synthesising electrically conductive graphene-based coagulated composite that could be utilised in the above-mentioned applications. Composites are prepared from graphene powder/ink and screen-printing ink (GP–SPI and GI–SPI, respectively) at different mass ratios, and the optimal composition is identified by brush coating on paper in the form of rectangular strips. As a proof of concept, at optimum mass ratios, the GP–SPI and GI–SPI composites exhibit electrical conductivities ranging 0.068–0.702 mS m−1 and 0.0303–0.1746 μS m−1, in order. The as-prepared conductive composites are then screen-printed onto a square with an area of 1 cm2 on ceramic, FR4, glass, paper, polyester and wood substrates. The coagulated GP–SPI and GI–SPI composites are compatible with all these substrates and yield a conductive coating, demonstrating their suitability in multifaceted applications. Furthermore, the method proposed herein eliminates the need for rare/precious expensive materials, state-of-the art equipment, highly skilled personnel and costs associated with the same, thereby broadening the avenues for low-cost, fluidic graphene-based functional composites.

Asymmetric Hydrogel Electrolyte Featuring a Customized Anode and Cathode Interfacial Chemistry for Advanced Zn-I2 Batteries.

An integrated asymmetric hydrogel electrolyte with a tailored composition and chemical structure on the cathode/anode-electrolyte interface is designed to boost the cost-effective, high-energy Zn-I2 battery. Such a configuration concurrently addresses the parasitic reactions on the Zn anode side and the polyiodide shuttle issue afflicting the cathode. Specifically, the Zn2+-cross-linked sodium alginate and carrageenan dual network (Carra-Zn-Alg) is adopted to guide the Zn2+ transport, achieving a dendrite-free morphology on the Zn surface and ensuring long-term stability. For the cathode side, the poly(vinyl alcohol)-strengthened poly(3,4-ethylenedioxythiophene)polystyrenesulfonate hydrogel (PVA-PEDOT) with high conductivity is employed to trap polyiodide and accelerate electron transfer for mitigating the shuttle effect and facilitating I2/I- redox kinetics. Attributing to the asymmetrical architecture with a customized interfacial chemistry, the optimized Zn-I2 cell exhibits a superior Coulombic efficiency of 99.84% with a negligible capacity degradation at 0.1 A g-1 and an enhanced stability of 10 000 cycles at 5 A g-1. The proposed asymmetric hydrogel provides a promising route to simultaneously resolve the distinct challenges encountered by the cathode and anode interfaces in rechargeable batteries.