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Capitalizing on massive sentiment diffusion and mobilization aided by mass media and social media nowadays, we introduce a general theory of host country sentiments to illuminate the granular, context-situated, and time dynamic power of social sentiments. We posit that host country is a value-laden context wherein a foreign entity's strategic action stimulates host country stakeholders' social sentiments and engagement in systems of discourses ("sentiment arousal"), mobilizes social sentiments toward the foreign entity ("sentiment competence"), and legitimizes social sentiments and the strategic action of the foreign entity ("sentiment resonance"). To test our theory, we employ a context of inward acquisitions by emerging market firms in an advanced economy, and postulate that host country sentiments toward objects of the inward acquisition (deal, acquirer, and inward investments from home country) will influence the likelihood of deal completion, an indication of host country legitimacy. We further highlight the patterns of host country sentiment dynamics, and showcase how sentiment volatility, wavelength, and augmentation exert heterogeneous effects on deal completion. Overall, we advocate a theory of host country sentiments in international management research that elucidates the interplay among host country sentiments, systems of social discourses, and multinational enterprise strategic outcomes in a host country. [ABSTRACT FROM AUTHOR]

3D printed energy storage materials and devices (3DP‐ESMDs) have become an emerging and cutting‐edge research branch in advanced energy fields. To achieve satisfactory electrochemical performance, energy storage interfaces play a decisive role in burgeoning ESMD‐based 3D printing. Hence, it is imperative to develop effective interface engineering routes toward desirable 3DP‐ESMDs. In this tutorial review, recent advances in interface engineering for 3DP‐ESMDs are comprehensively provided and in‐depth discussion is offered. To begin with, basic interface engineering principles are introduced. Critical interface engineering strategies including 3D printing‐enabled structural design, composition modification, protective layer design, and 3D printed device optimization are then summarized and illustrated, accompanied by a discussion of pioneering work on 3D printed rechargeable batteries and electrochemical capacitors that has been made through significant interface engineering strategies. Finally, perspectives on interface engineering approaches in future 3DP‐ESMDs are presented. [ABSTRACT FROM AUTHOR]

A unique configuration based on internally integrated electrodes is proposed for flexible hybrid zinc-ion capacitor (HZIC) devices. An in-depth charge storage process is studied, confirming the high electrochemical promise of HZICs for future practical applications. [ABSTRACT FROM AUTHOR]

Advanced wearable self‐powered energy systems that simultaneously achieve energy harvesting and energy storage offer exciting opportunities for flexible electronics, information communication, and even intelligent environmental monitoring. However, building and integrating synergistic energy storage from energy harvester unit into a single power source is highly challenging. Herein, a unique 3D printing‐directed synergistic design of high‐performance zinc‐ion hybrid capacitors (ZIHCs) and triboelectric nanogenerators (TENGs) is proposed for the all‐in‐one self‐powered wearable energy wristband. With advanced ink design, high‐performance flexible ZIHCs are built up as the excellent energy storage unit with remarkable electrochemical behaviors and synergistic matching from TENGs. An exceptional device capacitance of 239.0 mF cm−2, moderate potential window, high‐rate capability, robust cycling stability, and excellent flexibility are achieved. Intrinsic charge storage process is also revealed, further demonstrating the outstanding electrochemical stability of the in‐plane flexible ZIHCs. Moreover, using 3D printing‐directed synergistic design, an advanced all‐in‐one self‐powered energy wristband is developed, where an efficient harvesting of body vibration/movement energy and a reliable storage of harvested energy are simultaneously realized, representing a substantial step toward future practical applications in portable and wearable electronics. [ABSTRACT FROM AUTHOR]

Multifunctional energy integration has drawn booming attention for portable devices and wearable electronics. Self-powered energy systems are considered as advanced integrated energy systems that can harvest and store sustainable environmental energy to stably power electronics. However, achieving synergistic or matchable electrochemical performance output for energy storage device parts remains challenging, which directly restricts further energy output of self-powered energy systems. Herein, we report flexible in-plane zinc-ion hybrid capacitors (ZIHCs) with synergistic electrochemical behaviors for self-powered energy systems. By designing and optimizing asymmetric interdigitated microelectrodes with favorable structures, an optimal device capacitance of 92.5 mF cm−2, a high energy density of 25.2 μW h cm−2, a moderate operating voltage of 1.6 V and an outstanding cycling stability (92% capacitance retention after 10 000 cycles) are achieved for ZIHCs. Owing to the outstanding and synergistic electrochemical performance of ZIHCs, self-powered energy systems integrated with in-plane ZIHCs and triboelectric nanogenerators deliver a desirable self-charging process and exceptional discharging ability in powering various electronics in the long term. These advances illustrate a great significance of in-plane ZIHCs for future advanced energy storage applications. [ABSTRACT FROM AUTHOR]

Ever‐growing demand to develop satisfactory electrochemical devices has driven cutting‐edge research in designing and manufacturing reliable solid‐state electrochemical energy storage devices (EESDs). 3D printing, a precise and programmable layer‐by‐layer manufacturing technology, has drawn substantial attention to build advanced solid‐state EESDs and unveil intrinsic charge storage mechanisms. It provides brand‐new opportunities as well as some challenges in the field of solid‐state energy storage. This review focuses on the topic of 3D printing for solid‐state energy storage, which bridges the gap between advanced manufacturing and future EESDs. It starts from a brief introduction followed by an emphasis on 3D printing principles, where basic features of 3D printing and key issues for solid‐state energy storage are both reviewed. Recent advances in 3D printed solid‐state EESDs including solid‐state batteries and solid‐state supercapacitors are then summarized. Conclusions and perspectives are also provided regarding the further development of 3D printed solid‐state EESDs. It can be expected that advanced 3D printing will significantly promote future evolution of solid‐state EESDs. [ABSTRACT FROM AUTHOR]

Earth‐abundant non‐precious‐metal‐based materials are promising candidates for low‐cost oxygen reduction reaction (ORR) catalysts. Within those elements, iron is the cheapest given the abundant resources. However, there are few iron‐based ORR catalysts given the difficulty of achieving good electrocatalytic activity and stability with them in comparison to cobalt‐ and nickel‐based catalysts. Moreover, the synthesis of iron‐based ORR catalysts is energy intense and normally requires complicated processes. This work reports an iron‐based covalent organic framework (COF) synthesized through a one‐step low‐temperature solid reaction, which is cost effective and energy saving. The iron‐based COF, named IPPc, shows a high four‐electron‐transfer reaction selectivity. After compositing it with reduced graphene oxide, the resulting composite preserves the high electron‐transfer reaction selectivity and displays a largely enhanced activity and stability. [ABSTRACT FROM AUTHOR]

Direct ink writing has emerged as one of the simplest 3D printing technologies for a wide range of applications including energy storage devices. Inks with high printability and desired functionality are the most important elements to achieve efficient 3D printing. Many printable inks have been reported; however, few were developed with high versality. In this paper, a versatile fabrication approach for various desirable 3D printable nanomaterial inks is presented for superior battery electrodes. By controlling the dispersing solvents, the inks' rheological properties are well tailored for 3D printing processes without sacrificing the weight ratio of electrode components. At high mass loading, 3D printed cellular LiFePO4 cathodes and Li4Ti5O12 anodes deliver high specific capacities of 168 (0.5C) and 171 mA h g−1 (1C), respectively, which are both close to their corresponding theoretical capacities. Meanwhile, high-rate capabilities and superior long-term cycling stabilities are also demonstrated for the obtained cellular high-loading cathodes and anodes. A 3D printed Li-ion full-cell battery also exhibits outstanding electrochemical performance. This work presents a strategy with high versality for advanced 3D printable nanomaterial inks for next-generation customized and high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

NASICON-type solid state electrolytes have attracted great interest in all-solid-state batteries, and many attempts have been applied to enhance the ionic conductivity. It is generally believed that low activation energy governs the high ionic conductivity while the prefactor, particularly migration entropy, is often overlooked. Here, employing a combination of electrochemical strain microscopy, speed of sound measurements, and electrochemical impedance spectra, we investigate the structure–property relationships governing ionic conduction behavior in the Li1−3xGaxZr2(PO4)3 system. A sharp increase in the prefactor upon Ga substitution is attributed to the increased migration entropy while the increase in activation energy can be rationalized in terms of the inductive effect. These two competitive factors determine the final ionic conductivity. [ABSTRACT FROM AUTHOR]

Micro-supercapacitors (MSCs) with excellent electrochemical behaviours and flexibility possess great promise for portable and wearable electronic devices. A novel type of hybrid-dimensional Fe2O3/graphene/Ag ink is developed and extruded into MSC electrodes through the direct ink writing-based three-dimensional (3D) printing. The optimal solid-state MSC device exhibits a maximum areal capacitance of 412.3 mF cm−2 at 2 mA cm−2, a correspondingly high energy density of 65.4 μWh cm−2 and 89% capacitance retention for over 5000 charge and discharge cycles. The superior electrochemical performance is profited by the high electron transport synergistically boosted by two-dimensional graphene nanosheets and one-dimensional Ag nanowires, and the high pseudocapacitive behaviours of Fe2O3 nanoparticles. The 3D printed MSC exhibits reliable flexibility with remarkable retention of 90.2% of its original capacitance after 500 bending cycles. The current 3D printing fabrication demonstrates an efficient route for advanced miniaturised electrochemical energy storage. [ABSTRACT FROM AUTHOR]

Ce4+ and Ca2+ modified La2Zr2O7 samples, La2Zr2O7, (La0.8Ce0.2)2(Zr0.7Ce0.3)2O7.2 and (La0.6Ce0.2Ca0.2)2(Zr0.7Ce0.3)2O7, were prepared by the co-precipitation method to obtain enhanced thermos-physical properties. Compared with La2Zr2O7, (La0.8Ce0.2)2(Zr0.7Ce0.3)2O7.2 and (La0.6Ce0.2Ca0.2)2(Zr0.7Ce0.3)2O7 both exhibited better sintering resistance, lower thermal conductivities, and higher thermal expansion coefficients. The underlying mechanism of the improved thermo-physical performance of La2Zr2O7 induced by Ce4+ and Ca2+ doping was discussed. The thermal conductivity and thermal expansion coefficient of (La0.6Ce0.2Ca0.2)2(Zr0.7Ce0.3)2O7 were 1.165 W·m−1·K−1 at 1450°C and 10.91 × 10−6 K−1, respectively, making it a promising material for the thermal barrier coatings (TBCs). [ABSTRACT FROM AUTHOR]

Micro-supercapacitor is a member of the miniaturized energy storage device family, which offers great advantages on power density and life span. However, the limited device capacitance and narrow voltage window limit its energy density, hindering its application. In the present work, a novel micro-pseudocapacitor (MPC) constructed via the facile extrusion-based 3D printing technique has been demonstrated to deliver efficient charge storage with high device capacitance and moderate voltage window. Such an asymmetric MPC is constructed with 3D-printing-enabled asymmetric interdigitated cellular microelectrodes; in which, one is Ni–Co–O nanosheets grown on macroporous 3D reduced GO (3DG) microelectrode and the other is MnO2 nanosheets grown on 3DG. Such an MPC offers facilitated fast electron transport, ionic diffusion, large number of active sites and desired porosity for electrolyte penetration. The asymmetric MPC shows a high specific capacity of 500 mC cm−2, an energy density of 90 μW h cm−2 and a voltage window of 1.3 V. A device cycling stability with 10 000 charge and discharge cycles is also achieved for the as-fabricated asymmetric MPCs. These encouraging results may open a new avenue to design and fabricate state-of-the-art miniaturized electrochemical energy storage devices with customized geometries. [ABSTRACT FROM AUTHOR]

Electrocatalysts have been used to split water into hydrogen and oxygen for their advantages in clean energy technologies. To reduce cost and enhance stability of electrocatalysts, intensive works have been done in recent decades. Although research on noble‐metal free electrocatalysts has achieved great progress, their full water splitting performance is still incomparable to that of noble metal based catalysts. For this reason, reducing content of noble metal in catalysts is a more practical way. In this work, we report our recent progress on developing bifunctional electrocatalyst based on nitrogen‐doped graphene chainmail wrapped IrCo alloy particles on nitrogen‐doped graphene (NG@IrCo/NG). Benefited from strong interaction among iridium, cobalt and nitrogen‐doped graphene, impressively high electrocatalytic activity of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in both acid and alkaline solutions, which are comparable to commercially used Pt/C and IrO2 electrocatalysts respectively, is found. Catalyst with the structure of nitrogen doped chainmail wrapping on metal core is found to have highly stable full water splitting performance. [ABSTRACT FROM AUTHOR]