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Some polymers are flexible, foldable, and wearable. Structural—functional composite is fabricated by adding inorganic fillers with functional properties. Up to date, compared with the polymer matrix, the composite prepared by polymer-inorganic fillers has lower flexibility, higher brittleness, and higher modulus of elasticity. In this paper, three-dimensional (3D) net-shaped submicron α-Al 2 O 3 , orthorhombic ZrO 2 , and rutile TiO 2 fiber were fabricated by solution blowing spinning on a large scale. On the contrary, the elastic modulus ( E ) of the composite prepared by this 3D ceramic fiber was greatly reduced, and the flexibility of the composite was higher than that of the polymer matrix. When the strain was 75%, the E of the 3D net-shaped Al 2 O 3 fiber-polydimethylsiloxane (PDMS) composite was 20% lower than that of PDMS. When the strain was 78%, the E of the 3D net-shaped TiO 2 fiber-PDMS and 3D net-shaped ZrO 2 fiber-PDMS composites decreased by 20% and 25%, respectively. This abnormal effect, namely the tunnel elastic enhancement effect, has great practical significance. In all-solid-state lithium-ion batteries, the composite inhibits lithium dendrite growth and the 3D inorganic network contributes to lithium ion transport. It is possible to promote the industrial production of low-cost and large-scale flexible solid-state lithium-ion batteries and it can enhance the energy storage density of energy storage materials. This novel idea also has bright prospects in flexible electronic materials.

Enabling recycling and improving performance are key challenges for next‐generation electrolytes for rechargeable batteries. Here, an equilibrium polymerization: trimethylene carbonate (TMC) ring‐opening polymerization, in the presence of lithium difluoro(oxalato)borate salt, is utilized to form an electrolyte in situ during coin cell fabrication for lithium batteries. This process creates a semi‐solid poly(trimethylene carbonate) electrolyte with high ambient ionic conductivity (0.52 mS cm−1), thermal stability (Td, 5% = 160 °C), and oxidative stability up to 4.7 V. Using this electrolyte with commercial lithium iron phosphate cathodes, results in 97% capacity retention after 350 cycles at 2C, achieving theoretical capacities of 170 mAh g−1 at 0.1C. The cells retain excellent performance at high current densities (86 mAh g−1 at 4C). Post‐use, the polymer can be separated from the salt and selectively recycled to pure starting monomer (TMC) through a solid‐state chemical recycling process. The recycled monomer, when repolymerized to reform the polycarbonate electrolyte, yields cells with performance identical to the original. The exploitation of polymerization‐depolymerization equilibria offers a useful strategy for enhancing battery performance, ensuring effective material recycling, and advancing a circular economy. A recyclable polycarbonate electrolyte is synthesized in situ in a lithium‐metal battery. Excellent cell performance is obtained owing to its high conductivity and (electro)chemical stability. The electrolyte is recovered after extended battery cycling, chemically recycled back to monomer, and repolymerized, obtaining comparable cell performance. This concept will help develop future recyclable polymer electrolytes and deliver a circular economy for batteries.

Psychological contract plays a critical role in knowledge sharing. In this paper, we have analyzed the influence of psychological contract and affective commitment to knowledge sharing in China. After using AMOS software for data processing by employing data on the questionnaire, which indicated that there are high consistency and stability and good convergence validity and construction reliability among variables, the multiple Ordinary Least Square(OLS) method was utilized in the study. There are 183 questionnaires were received in the experiment. After analysis, 157 questionnaires were valid for the research; the effective recovery rate was about to 86%. Based on the study, the conclusion could be conducted that the relationship contract and development contract of enterprise technical staff have positive impacts to knowledge sharing, On the contrary, the transaction contract has a negative impact to knowledge sharing.

All-solid-state batteries with a Li anode and ceramic electrolyte have the potential to deliver a step change in performance compared with today’s Li-ion batteries 1 , 2 . However, Li dendrites (filaments) form on charging at practical rates and penetrate the ceramic electrolyte, leading to short circuit and cell failure 3 , 4 . Previous models of dendrite penetration have generally focused on a single process for dendrite initiation and propagation, with Li driving the crack at its tip 5 – 9 . Here we show that initiation and propagation are separate processes. Initiation arises from Li deposition into subsurface pores, by means of microcracks that connect the pores to the surface. Once filled, further charging builds pressure in the pores owing to the slow extrusion of Li (viscoplastic flow) back to the surface, leading to cracking. By contrast, dendrite propagation occurs by wedge opening, with Li driving the dry crack from the rear, not the tip. Whereas initiation is determined by the local (microscopic) fracture strength at the grain boundaries, the pore size, pore population density and current density, propagation depends on the (macroscopic) fracture toughness of the ceramic, the length of the Li dendrite (filament) that partially occupies the dry crack, current density, stack pressure and the charge capacity accessed during each cycle. Lower stack pressures suppress propagation, markedly extending the number of cycles before short circuit in cells in which dendrites have initiated. Analysis of dendrite initiation, owing to filling of pores with lithium by means of microcracks, and propagation, caused by wedge opening, shows that there are two separate processes during dendrite failure of lithium metal solid-state batteries.

The mechanical properties of solder joints highly depend on the interfacial reaction between the solders and the metallization on substrates. In this work, we electroplated Co–P films with various compositions on the Cu pads of printed circuit boards and fabricated Sn-3.8 wt% Ag-0.7 wt% Cu/Co–P ball grid array (BGA) solder joints. The BGA solder joints were annealed at 150 °C for 100, 200, 500, and 1000 h and the shear strength of these joints was measured. When the P content of the Co–P metallization was increased from 2.3 to 18.8 at.%, the shear strength after 1000 h annealing initially rose to 107.9 MPa at a P content of 8.5 at.%, then decreased to 84.3 MPa at a P content of 12.5 at.%, and again increased to 96.0 MPa at a P content of 18.8 at.%. The enhancement of the shear strength of the joints with Co-8.5 at.% P, Co-12.5 at.% P, and Co-18.8 at.% P films was 109.5%, 63.7%, and 86.4% in comparison to the joints without Co–P metallization, respectively. The interfacial reaction between the Sn–Ag–Cu (SAC) solder and Co–P films during annealing and the fractured surfaces of the solder joints after the shear test were studied. For the joints with Co-8.5 at.% P and Co-18.8 at.% P films, a thick layer of CoSn3 was formed at the interfaces during annealing, which enhanced the shear strength. For the joints with Co-12.5 at.% P metallization, a thin layer of Co–Sn–P was formed at the interfaces and was peeled off layer by layer with prolongation of the annealing time. The spalled Co–Sn–P was mixed with the solder matrix, increasing the shear strength of the solder joints. The shear strength of the SAC/Co-12.5 at.% P joints was less than that of the joints with Co-8.5 at.% P and Co-18.8 at.% P films because no CoSn3 formed. Therefore, the composition of Co–P metallization played an important role in the interfacial reaction of the SAC/Co–P solder joints, which in turn affected the shear strength of the solder joints. Our experimental results show that the electroplated Co–P film is a promising candidate as the metallization for BGA solder joints.

The three-roll bending forming of sheet metal is an important and flexible manufacturing process due to simple configuration. It is suitable for forming large sheet parts with complex, curved faces. Most researches on roll bending forming of large workpiece are mainly based on experiments and explain the process through macroscopic metal deformation. An analytical model and ABAQUS finite element model (FEM) are proposed in this paper for investigating the three-roll bending forming process. A reasonably accurate relationship between the downward inner roller displacement and the desired springback radius (unloaded curvature radius) of the bent plate is yielded by both analytical and finite element approaches, which all agree well with experiments. Then, the three-roll bending forming process of a semi-circle-shaped workpiece with 3,105 mm (length) × 714 mm (width) × 545 mm (height) is simulated with FEM established by the optimum tool and process parameters. Manifested by the experiment for three-roll bending forming of this workpiece, the numerical simulation method proposed yields satisfactory performance in tool and process parameters optimization and workpiece forming. It can be taken as a valuable mathematical tool used for three-roll bending forming of large area sheet metal.

Based on Hill’s yielding criterion and plane strain condition, the explicit expressions of elastoplastic constitutive model are derived in this paper which takes into account the effects of transverse stress, neutral surface shifting, and sheet thickness thinning on the sheet springback of air-bending. Then, this model is embedded into ABAQUS software platform by means of programming. Finally, 3D ABAQUS finite-element models (FEM), used to form the semiellipse-shaped workpiece with super length and large opening of sheet metal, are established, and the multiple-step incremental air-bending forming and springback processes are simulated. The simulation and experiment results show that the data predicted with the new constructed constitutive model under the plane strain condition are in much better agreement with experimental data than those predicted with the constitutive model built-in ABAQUS. It can be taken as a valuable mathematical tool used for multiple-step incremental air-bending forming simulation of large area sheet metal.

Some polymers are flexible, foldable, and wearable. Structural-functional composite is fabricated by adding inorganic fillers with functional properties. Up to date, compared with the polymer matrix, the composite prepared by polymer-inorganic fillers has lower flexibility, higher brittleness, and higher modulus of elasticity. In this paper, three-dimensional (3D) net-shaped submicron [alpha]-[Al.sub.2][O.sub.3], orthorhombic Zr[O.sub.2], and rutile Ti[O.sub.2] fiber were fabricated by solution blowing spinning on a large scale. On the contrary, the elastic modulus (E) of the composite prepared by this 3D ceramic fiber was greatly reduced, and the flexibility of the composite was higher than that of the polymer matrix. When the strain was 75%, the E of the 3D net-shaped [Al.sub.2][O.sub.3] fiber-polydimethylsiloxane (PDMS) composite was 20% lower than that of PDMS. When the strain was 78%, the E of the 3D net-shaped Ti[O.sub.2] fiber-PDMS and 3D net-shaped Zr[O.sub.2] fiber-PDMS composites decreased by 20% and 25%, respectively. This abnormal effect, namely the tunnel elastic enhancement effect, has great practical significance. In all-solid-state lithium-ion batteries, the composite inhibits lithium dendrite growth and the 3D inorganic network contributes to lithium ion transport. It is possible to promote the industrial production of low-cost and large-scale flexible solid-state lithium-ion batteries and it can enhance the energy storage density of energy storage materials. This novel idea also has bright prospects in flexible electronic materials.

Nickel–Cobalt oxide nanotubes are prepared by a simple electrospinning technique based on a phase-separation mechanism. Extra tetraethyl orthosilicate (Si(OC2H5)4) is introduced and removed by design to obtain nanotube structure. The prepared nanotubes deliver remarkable electrochemical performance as the lithium-ion batteries anode materials. It possesses a capacity of 924 mAh/g after 95 cycles at 100 mA/g. At 2000 mA/g, it has a high capacity of 770 mAh/g, and still has 255 mAh/g at 1000 mA/g after 500 cycles. The outstanding electrochemical performance is attributed to the unique hierarchical tubular nanostructures design. This simple method opens new opportunities for fabricating practical nanostructured anode materials.

A broadband six-way out-of-phase substrate-integrated waveguide (SIW) power divider was designed, analyzed, and fabricated for low loss and out of phase dividing applications. The SIW technology was used to realize the power divider; where it consists of a central dual-disc probe connected with coaxial outer-conductor impedance matching transformer and six SIW-to-microstrip transitions as output probes. Three of the SIW-to-microstrip transitions are located at the top plane, whereas the other three are at the bottom plane of the power divider to achieve the out-of-phase dividing functioning. These transitions are all the same in size and shape for symmetry reason. Good transmissions from coaxial input port to six-way SIW power divider were also achieved. There is a reasonable agreement between measured and simulated results.