Polymer‐based electrolytes have attracted ever‐increasing attention for all‐solid‐state lithium (Li) metal batteries due to their ionic conductivity, flexibility, and easy assembling into batteries, ...and are expected to overcome safety issues by replacing flammable liquid electrolytes. However, it is still a critical challenge to effectively block Li dendrite growth and improve the long‐term cycling stability of all‐solid‐state batteries with polymer electrolytes. Here, the interface between novel poly(vinylidene difluoride) (PVDF)‐based solid electrolytes and the Li anode is explored via systematical experiments in combination with first‐principles calculations, and it is found that an in situ formed nanoscale interface layer with a stable and uniform mosaic structure can suppress Li dendrite growth. Unlike the typical short‐circuiting that often occurs in most studied poly(ethylene oxide) systems, this interface layer in the PVDF‐based system causes an open‐circuiting feature at high current density and thus avoids the risk of over‐current. The effective self‐suppression of the Li dendrite observed in the PVDF–LiN(SO2F)2 (LiFSI) system enables over 2000 h cycling of repeated Li plating–stripping at 0.1 mA cm−2 and excellent cycling performance in an all‐solid‐state LiCoO2||Li cell with almost no capacity fade after 200 cycles at 0.15 mA cm−2 at 25 °C. These findings will promote the development of safe all‐solid‐state Li metal batteries.
A nanoscale interface layer with multicomponents and uniform mosaic microstructure in situ forms between a PVDF–LiFSI electrolyte and Li anode, and can effectively suppress the lithium dendrite, thus enabling long‐term cycling stability and high safety of full cells, promoting the development of next‐generation all‐solid‐state Li metal batteries.
High‐energy‐density polymer nanocomposites with high‐dielectric‐constant ceramic nanoparticles as the reinforcement exhibit great potential for energy storage applications in modern electronic and ...electrical systems. However, the decline of breakdown strength by high loading of ceramic nanoparticles hinders this composite approach from sustainable promotion of energy density. In this work, an approach is proposed and demonstrated by constructing gradient distribution of the spherical ceramic nanoparticles in the polymer matrix. These gradient‐structured nanocomposites possess remarkably improved mechanical and electrical behaviors, which give rise to ultrahigh breakdown strength and much‐promoted energy density. Moreover, this enhancement effect can be further enlarged via increasing the grades number of gradient structures. This work provides an effective strategy for developing flexible high‐energy‐density polymer/ceramic nanocomposites for dielectric and energy storage applications.
Gradient distribution of ceramic nanoparticles in polymer films is constructed through a layer‐by‐layer process, which greatly improves the electrical and mechanical properties of polymer nanocomposites, resulting in ultrahigh breakdown strength and energy density. This work provides an effective strategy for developing flexible high‐energy‐density polymer/ceramic nanocomposites for dielectric and energy storage applications.
Solid‐state lithium (Li) batteries using solid electrolytes and Li anodes are highly desirable because of their high energy densities and intrinsic safety. However, low ambient‐temperature ...conductivity and poor interface compatibility of solid electrolytes as well as Li dendrite formation cause large polarization and poor cycling stability. Herein, a high transference number intercalated composite solid electrolyte (CSE) is prepared by the combination of a solution‐casting and hot‐pressing method using layered lithium montmorillonite, poly(ethylene carbonate), lithium bis(fluorosulfonyl)imide, high‐voltage fluoroethylene carbonate additive, and poly(tetrafluoroethylene) binder. The electrolyte presents high ionic conductivity (3.5 × 10−4 S cm−1), a wide electrochemical window (4.6 V vs Li+/Li), and high ionic transference number (0.83) at 25 °C. In addition, a 3D Li anode is also fabricated via a facile thermal infusion strategy. The synergistic effect of high transference number intercalated electrolyte and 3D Li anode is more favorable to suppress Li dendrites in a working battery. The solid‐state batteries based on LiFePO4 (Al2O3 @ LiNi0.5Co0.2Mn0.3O2), CSE, and 3D Li deliver admirable cycling stability with discharge capacity 145.9 mAh g−1 (150.7 mAh g−1) and capacity retention 91.9% after 200 cycles at 0.5 C (92.0% after 100 cycles at 0.2 C) at 25 °C. This work affords a splendid strategy for high‐performance solid‐state battery.
The intercalated composite solid electrolyte presents a large ionic conductivity and high ionic transference number. The synergistic effect of the high transference number intercalated electrolytes and 3D lithium anode effectively suppresses lithium dendrites. The assembled batteries deliver a high cycling performance, demonstrating a promising strategy for ambient‐temperature solid‐state lithium metal batteries.
Solid‐state batteries (SSBs) are considered as one of the most promising candidates for the next‐generation energy‐storage technology, because they simultaneously exhibit high safety, high energy ...density, and wide operating temperature range. The replacement of liquid electrolytes with solid electrolytes produces numerous solid–solid interfaces within the SSBs. A thorough understanding on the roles of these interfaces is indispensable for the rational performance optimization. In this review, the interface issues in the SSBs, including internal buried interfaces within solid electrolytes and composite electrodes, and planar interfaces between electrodes and solid electrolyte separators or current collectors are discussed. The challenges and future directions on the investigation and optimization of these solid–solid interfaces for the production of the SSBs are also assessed.
Solid–solid interfaces play a critical role in the electrochemical performance of solid‐state batteries. This review provides an overview on the solid–solid interfaces from aspects of structural features, Li‐ion transport, interfacial contact, and electro‐chemical reactions. The existing interface issues and improvement strategies are discussed. Opportunities and future trends on the investigation and optimization of these interfaces are highlighted.
The construction of bifunctional electrode materials for hydrogen evolution reaction (HER) and lithium‐ion batteries (LIBs) has been a hot topic of research. Herein, metal–organic frameworks (MOFs) ...derived micro‐/nanostructured Ni2P/Ni hybrids with a porous carbon coating (denoted as Ni2P/Ni@C) are prepared using a feasible pyrolysis–phosphidation strategy. On the one hand, the optimal Ni2P/Ni@C catalyst exhibits superior HER performance with a low overpotential of 149 mV versus a reversible hydrogen electrode (RHE) at 10 mA cm−2 and excellent durability. The density functional theory computations verify that the strong synergistic effect between Ni2P and Ni could optimize the electronic structure, thus rendering the enhanced electrocatalytic performance. On the other hand, the Ni2P/Ni@C electrode displays a reversible capacity of 597 mAh g−1 after 1000 cycles at 1000 mA g−1 and improved rate capability as an anode for LIBs, owing to the well‐organized micro‐/nanostructure and conductive Ni core. In addition, the electrochemical reaction mechanism of the Ni2P/Ni@C electrode upon lithiation/delithiation is investigated in detail via ex situ X‐ray powder diffraction and X‐ray photoelectron spectroscopy methods. It is expected that the facile and controllable approach can be extended to fabricate other MOF‐based metal phosphides/metal hybrids for electrochemical energy storage and conversion systems.
Metal‐organic framework derived micro/nano‐structured Ni2P/Ni hybrids with a porous carbon coating are successfully prepared. As hydrogen evolution reaction catalysts, both experimental and computational results verify that the strong synergistic effect between Ni2P and Ni renders an enhanced electrocatalytic performance. As anode for Li‐ion batteries, the well‐organized micro/nano‐structure and the conductive Ni core jointly promote the electrochemical reaction kinetics.
Manipulating microstructures of composites in three dimensions has been a long standing challenge. An approach is proposed and demonstrated to fabricate artificial nanocomposites by controlling the ...3D distribution and orientation of oxide nanoparticles in a polymer matrix. In addition to possessing much enhanced mechanical properties, these nanocomposites can sustain extremely high voltages up to ≈10 kV, exhibiting high dielectric breakdown strength and low leakage current. These nanocomposites show great promise in resolving the paradox between dielectric constant and breakdown strength, leading to ultrahigh electrical energy density (over 2000% higher than that of the bench‐mark polymer dielectrics) and discharge efficiency. This approach opens up a new avenue for the design and modulation of nanocomposites. It is adaptable to the roll‐to‐roll fabrication process and could be employed as a general technique for the mass production of composites with intricate nanostructures, which is otherwise not possible using conventional polymer processing techniques.
Artificial nanocomposites fabricated by controlling the 3D distribution and orientation of oxide nanoparticles in a polymer matrix enable much enhanced mechanical and electrical properties along the out‐of‐plane direction, exhibiting high dielectric breakdown strength and low leakage current. These microstructured nanocomposites show great promise in resolving the paradox between dielectric constants and breakdown strength, leading to ultrahigh electrical energy density and discharge efficiency.
Multiferroic magnetoelectric composite systems such as ferromagnetic‐ferroelectric heterostructures have recently attracted an ever‐increasing interest and provoked a great number of research ...activities, driven by profound physics from coupling between ferroelectric and magnetic orders, as well as potential applications in novel multifunctional devices, such as sensors, transducers, memories, and spintronics. In this Review, we try to summarize what remarkable progress in multiferroic magnetoelectric composite systems has been achieved in most recent few years, with emphasis on thin films; and to describe unsolved issues and new device applications which can be controlled both electrically and magnetically.
Recent progress in multiferroic magnetoelectric composite systems such as bilayered magnetic‐ferroelectric heterostructures where magnetic and ferroelectric orders coexist are reviewed. Strong magnetoelectric couplings across the magnetic‐ferroelectric interface lead to magnetic (or electric)‐field control of electric polarization (or magnetization), which promises new device applications such as sensors, transducer, oscillators, phase shifters, memory devices, and so on, controlled both electrically and magnetically.
Solid-state batteries (SSBs) have recently been revived to increase the energy density and eliminate safety concerns associated with conventional Li-ion batteries with flammable liquid electrolytes. ...To achieve large-scale, low-cost production of SSBs as soon as possible, it would be advantageous to modify the mature manufacturing platform, involving slurry casting and roll-to-roll technologies, used for conventional Li-ion batteries for application to SSBs. However, the manufacturing of SSBs depends on the development of suitable solid electrolytes. Inorganic–polymer composite electrolytes combine the advantages of inorganic and polymer solid electrolytes, making them particularly suitable for the mass production of SSBs. In this Review, we discuss the properties of solid electrolytes comprising inorganic–polymer composites and outline the design of composite electrolytes for realizing high-performance devices. We also assess the challenges of integrating the composite electrolytes into batteries, which will enable the mass production of SSBs.Inorganic–polymer composites have emerged as viable solid electrolytes for the mass production of solid-state batteries. In this Review, we examine the properties and design of inorganic–polymer composite electrolytes, discuss the processing technologies for multilayer and multiphase composite structures, and outline the challenges of integrating composite electrolytes into solid-state batteries.
Multiferroic heterostructures can be synthesized by integrating monolithic ferroelectric and magnetic materials, with interfacial coupling between electric polarization and magnetization, through the ...exchange of elastic, electric, and magnetic energy. Although the nature of the interfaces remains to be unraveled, such cross coupling can be utilized to manipulate the magnetization (or polarization) with an electric (or magnetic) field, known as a converse (or direct) magnetoelectric effect. It can be exploited to significantly improve the performance of or/and add new functionalities to many existing or emerging devices such as memory devices, tunable microwave devices, sensors, etc. The exciting technological potential, along with the rich physical phenomena at the interface, has sparked intensive research on multiferroic heterostructures for more than a decade. Here, we summarize the most recent progresses in the fundamental principles and potential applications of the interface‐based magnetoelectric effect in multiferroic heterostructures, and present our perspectives on some key issues that require further study in order to realize their practical device applications.
Multiferroic heterostructures integrating ferroelectric and magnetic materials exhibit strong magnetoelectric coupling due to the complex interplay between spin, orbit, charge, and lattice order parameters across the hetero‐interface, which makes them technologically very attractive for the near future. Fundamental principles and potential device applications of magnetoelectric coupling in multiferroic heterostructures are reviewed using examples from recent reports.
MXenes have exhibited potential for application in flexible devices owing to their remarkable electronic, optical, and mechanical properties. Printing strategies have emerged as a facile route for ...additive manufacturing of MXene‐based devices, which relies on the rational design of functional inks with appropriate rheological properties. Herein, aqueous MXene/xanthan gum hybrid inks with tunable viscosity, excellent printability, and long‐term stability are designed. Screen‐printed flexible MXene films using such hybrid inks exhibit a high conductivity up to 4.8 × 104 S m−1, which is suitable to construct multifunctional devices mainly including electromagnetic shielding, Joule heaters, and piezoresistive sensors. The average electromagnetic interference (EMI) shielding value can reach to 40.1 dB. In the Joule heater, the heating rate of printed MXene film can reach 20 °C s−1 under a driving voltage of 4 V, with a highest steady‐state temperature of 130.8 °C. An MXene‐based piezoresistive sensor prepared by the printing interdigital electrode also presents good sensing performance with a short response time of 130 ms and wide pressure region up to 30 kPa. As a result, screen‐printed MXene film exhibits reinforced multifunctional performance, which is promising for application in the next‐generation of intelligent and wearable devices.
Aqueous MXene/xanthan gum hybrid inks with tunable viscosity, excellent printability, and long‐term stability are formulated for screen printing flexible devices. The hybrid inks can be screen‐printed into diverse patterns with high conductivity and excellent mechanical flexibility, all contributing to the fabrication of multifunctional devices with outstanding EMI, Joule heater, and piezoresistive sensor performances.
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