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Abstract Ionogels are promising material candidates for ionotronics due to their excellent ionic conductivity, stretchability, and thermal stability. However, it is challenging to develop 3D printable ionogels with both excellent electrical and mechanical properties. Here, we report a highly conductive and stretchable nanostructured (CSN) ionogel for 3D printing ionotronic sensors. We propose the photopolymerization-induced microphase separation strategy to prepare the CSN ionogels comprising continuous conducting nanochannels intertwined with cross-linked polymeric framework. The resultant CSN ionogels simultaneously achieves high ionic conductivity (over 3 S m−1), high stretchability (over 1500%), low degree of hysteresis (0.4% at 50% strain), wide-temperature-range thermostability (−72 to 250 °C). Moreover, its high compatible with DLP 3D printing enables the fabrication of complex ionogel micro-architectures with high resolution (up to 5 μm), which allows us to manufacture capacitive sensors with superior sensing performances. The proposed CSN ionogel paves an efficient way to manufacture the next-generation capacitive sensors with enhanced performance.

Thick panel origami holds great potential in engineering structures, but conventional fabrication processes limit their design and applications. Here the authors report a multimaterial 3D printing-based design and fabrication strategy for thick-panel origami structures with push-to-pull deformation.

Multimaterial 3D printing using digital light processing (DLP) is challenging because multimaterial switching methods require direct contact onto the printed part to remove residual resin. Here, the authors report a DLP-based centrifugal multimaterial 3D printing method to generate large-volume heterogeneous 3D objects where composition, property and function are programmable at voxel scale.

Based on phase-change heat storage backfill, paraffin microcapsules were selected as the phase change material and were directly mixed with backfill materials for preparing backfill specimens. The mechanical and thermal properties of specimens with different paraffin percentages and slurry concentrations were tested and analyzed. The results show that compressive strength gradually decreases with an increasing paraffin percentage while it significantly increases with increasing slurry concentration, thermal conductivity decreases with increasing paraffin percentage and specific heat capacity increases with an increasing paraffin percentage and slurry concentration. For a paraffin percentage from 0% to 10%, compressive strength decreases by an average of 22.5%, thermal conductivity decreases by an average of 43.8% and specific heat capacity increases by an average of 8.7% at a phase-change temperature of 30 °C. For a slurry concentration from 68% to 72%, compressive strength increases by an average of 4.12 times, and specific heat capacity increases by an average of 3.5% at a phase-change temperature of 30 °C. The weakening effect of phase-change materials on compressive strength can be effectively improved by the increase of slurry concentration, and the increases of paraffin percentage and slurry concentration can both improve the sensible heat storage capacity of backfill materials.

While not affecting electrochemical performance of energy storage devices, integrating multi-functional properties such as electrochromic functions into energy storage devices can effectively promote the development of multifunctional devices. Compared with inorganic electrochromic materials, organic materials possess the significant advantages of facile preparation, low cost, and large color contrast. Specifically, most polymer materials show excellent electrochemical properties, which can be widely used in the design and development of energy storage devices. In this article, we focus on the application of organic electrochromic materials in energy storage devices. The working mechanisms, electrochemical performance of different types of organics as well as the shortcomings of organic electrochromic materials in related devices are discussed in detail.

Additive manufacturing techniques have shown great promise in changing the way batteries can be designed due to their excellent geometry controllability, process flexibility and high sustainability in manufacturing complex-shaped structures, which have been progressively applied in design of high-performance lithium batteries. In this review, the latest advances in 3D printed lithium batteries have been summarized with a focus on the fundamentals of representative additive manufacturing techniques involving the operation mechanisms, manufacturing accuracy, respective advantages and challenges. In addition, the general 3D printing design principles in module architectures, materials selection and battery configurations for developing high performance lithium batteries are also systematically discussed. Finally, pertinent insights into the future perspectives of 3D printed lithium batteries have been emphasized, expecting to enlighten the research directions of practical applications of 3D printed batteries.

This study aims to investigate the impact of the High Pressure Selective Catalytic Reduction system (SCR-HP) on a large marine two-stroke engine performance parameters by employing thermodynamic modelling. A coupled model of the zero-dimensional type is extended to incorporate the modelling of the SCR-HP components and the Control Bypass Valve (CBV) block. This model is employed to simulate several scenarios representing the engine operation at both healthy and degraded conditions considering the compressor fouling and the SCR reactor clogging. The derived results are analysed to quantify the impact of the SCR-HP on the investigated engine performance. The SCR system pressure drop and the cylinder bypass valve flow cause an increase of the engine Specific Fuel Oil Consumption (SFOC) in the range 0.3–2.77 g/kWh. The thermal inertia of the SCR-HP is mainly attributed to the SCR reactor, which causes a delayed turbocharger response. These effects are more pronounced at low engine loads. This study supports the better understanding of the operating characteristics of marine two-stroke diesel engines equipped with the SCR-HP and quantification of the impact of the components degradation on the engine performance.

Porous materials as electrode materials have demonstrated numerous benefits for high-performance Zn-ion batteries in recent years. In brief, porous materials as positive electrodes provide distinctive features such as faster electron transport, shorter ion diffusion distance, and richer electroactive reaction sites, which improve the kinetics of positive electrode reactions and achieve higher rate capacity. On the other hand, the porous structures as negative electrodes also exhibit electrochemical properties possessing higher surface area and reducing local current density, which favors the uniform Zn deposition and restrains the dendrite formation. In view of their advantages, porous electrode materials for ZIB are expected to be extensively applied in electric and hybrid electric vehicles and portable electronic devices. In this review, we highlight the methods of synthesizing porous electrode materials and discuss the mechanism of action of porous structures as electrodes on their electrochemical properties. At the end of this review, the perspectives on the future development of porous materials in the field of electrochemical energy storage are also discussed.

A PCM was added to filling materials in an appropriate proportion to realize the effective collection and storage of geothermal energy. Based on the theory of heat transfer and similarity, the heat-storage performance of filling body was numerically simulated in different states, then, the influences of paraffin proportion, initial temperature of filling body, surrounding rock temperature, stope air-flow temperature, and velocity on the heat-storage behavior of filling body were analyzed. The results revealed that reducing the initial heat-storage temperature of filling body, increasing surrounding rock temperature, and increasing the air-flow temperature in the stope all effectively increased the heatstorage capacity of filling body. In which the influence of initial temperature and surrounding rock temperature were more significant. At the end of 16 hours heatstorage period, when the initial temperature of filling body was reduced from 24 °C to 18 °C, the heat transfer capacity of filling body without paraffin and that with 5% paraffin decreased by 2.85 · 103 kJ and 2.40 · 103 kJ, respectively. When surrounding rock temperature increased from 35 °C to 45 °C, the amount of heat stored by two bodies increased by 3.89 · 103 kJ and 4.51 · 103 kJ, respectively. [ABSTRACT FROM AUTHOR]

4D printing enables 3D printed structures to change shape over "time" in response to environmental stimulus. Because of relatively high modulus, shape memory polymers (SMPs) have been widely used for 4D printing. However, most SMPs for 4D printing are thermosets, which only have one permanent shape. Despite the efforts that implement covalent adaptable networks (CANs) into SMPs to achieve shape reconfigurability, weak thermomechanical properties of the current CAN-SMPs exclude them from practical applications. Here, we report reconfigurable 4D printing via mechanically robust CAN-SMPs (MRC-SMPs), which have high deformability at both programming and reconfiguration temperatures (>1400%), high Tg (75°C), and high room temperature modulus (1.06 GPa). The high printability for DLP high-resolution 3D printing allows MRC-SMPs to create highly complex SMP 3D structures that can be reconfigured multiple times under large deformation. The demonstrations show that the reconfigurable 4D printing allows one printed SMP structure to fulfill multiple tasks.. [ABSTRACT FROM AUTHOR]