Suppression of Vanadium Oxide Dissolution via Cation Metathesis within a Coordination Supramolecular Network for Durable Aqueous Zn-V2 O5 Batteries.

Aqueous zinc metal batteries (ZMBs) are a promising sustainable technology for large-scale energy storage applications. However, the water is often associated with problematic parasitic reactions on both anode and cathode, leading to the low durability and reliability of ZMBs. Here, a multifunctional separator for the Zn-V2 O5 batteries by growing the coordination supramolecular network (CSN:Zn-MBA, MBA = 2-mercaptobenzoic acid) on the conventional non-woven fabrics (NWF) is developed. CSN tends to form a stronger coordination bond as a softer cation, enabling a thermodynamically preferred Zn2+ to VO2 + substitution in the network, leading to the formation of VO2 -MBA interface, that strongly obstructs the VO2 (OH)2 - penetration but simultaneously allows Zn2+ transfer. Moreover, Zn-MBA molecules can adsorb the OTF- and distribute the interfacial Zn2+ homogeneous, which facilitate a dendrite-free Zn deposition. The Zn-V2 O5 cells with Zn-MBA@NWF separator realize high capacity of 567 mAh g-1 at 0.2 A g-1 , and excellent cyclability over 2000 cycles with capacity retention of 82.2% at 5 A g-1 . This work combines the original advantages of the template and new function of metals via cation metathesis within a CSN, provides a new strategy for inhibiting vanadium oxide dissolution.

A Two-Dimensional Porphyrin Coordination Supramolecular Network Cathode for High-Performance Aqueous Dual-Ion Battery.

Iodine has great potential in the energy storage, but high solubility of I3 - has seriously delayed its promotion. Benefited from abundant active sites and the open channel, two-dimensional coordination supramolecular networks (2D CSNs) is considered to be a candidate for the energy storage. Herein, a 2D porphyrin-CSN cathode named Zn-TCPP for aqueous iodine dual-ion battery (DIB) shows an excellent specific capacity of 278 mAh g-1 , and a high energy density of 340 Wh kg-1 at 5 A g-1 , as well as a durable cycle performance of 5000 cycles and a high Coulombic efficiency of 98 %. Molecular orbital theory, UV/VIS, Raman spectroscopy and density functional theory (DFT) calculations reveal charge-transfer interaction between the donor of porphyrin nitrogen and the acceptor of I3 - , and computational fluid dynamics (CFD) simulations demonstrate the contribution of 2D layered network structure of Zn-TCPP to the penetration of I3 - .

Anchoring I3- via Charge-Transfer Interaction by a Coordination Supramolecular Network Cathode for a High-Performance Aqueous Dual-Ion Battery.

Iodine is considered to have broad application prospects in the field of electrochemical energy storage. However, the high solubility of I3- severely hampers its practical application, and the lack of research on the anchoring mechanism of I3- has seriously hindered the development of advanced cathode materials for iodine batteries. Herein, based on the molecular orbital theory, we studied the charge-transfer interaction between the acceptor of I3- with a σ* empty antibonding orbital and the donor of pyrimidine nitrogen with lone-pair electrons, which is proved by the results of UV-vis absorption spectroscopy, Raman spectroscopy, and density functional theory (DFT) calculations. The prepared dual-ion battery (DIB) exhibits a high voltage platform of 1.2 V, a remarkable discharge-specific capacity of up to 207 mAh g-1, and an energy density of 233 Wh kg-1 at a current density of 5 A g-1, as well as outstanding cycle stability (operating stably for 5000 cycles) with a high Coulombic efficiency of 97%, demonstrating excellent electrochemical performance and a promising prospect in stationary energy storage.

Constructing Hydrophobic Interface with Close-Packed Coordination Supramolecular Network for Long-Cycling and Dendrite-Free Zn-Metal Batteries.

Commercialization of aqueous zinc-metal batteries remains unrealistic due to the substantial dendrite growth and side reaction issues on the zinc anodes. It is highly demanded to develop easy-to-handle approaches for constructing stable, dense, as well as homogeneous solid anode/electrolyte interfaces. Herein, the authors construct the zinc anode interface with a close-packed Zn-TSA (TSA = thiosalicylate) coordination supramolecular network through the facile and up-scalable wet-chemical method. The hydrophobic Zn-TSA network can block solvated water and establish a solid-state diffusion barrier to well-distribute the interfacial Zn2+ , thus inhibiting hydrogen evolution and zinc dendrite growth on the anode. Meanwhile, the Zn-TSA network induces the formation of a uniform and stable solid electrolyte interphase composed of multiple inorganic-organic compounds. This denser structure can accommodate and self-heal the crack/degradation of the anode interphase associated with the repeated volume changes, and suppress the generation of detrimental by-product, Znx (OTF- )y (OH)2x-y ·nH2 O. Such a rationally fabricated anode/electrolyte interface further endows the assembled symmetric cells with superior plating/stripping stability for over 2000 h without dendrite formation (at 1 mA cm-2 and 1 mAh cm-2 ). Furthermore, this zinc anode has practical application in the Zn-MoS2 and Zn-V2 O5 full cells. This study provides a new train of thought for constructing the dense interface of zinc-metal anode.

In situ design of advanced titanium alloy with concentration modulations by additive manufacturing.

Additive manufacturing is a revolutionary technology that offers a different pathway for material processing and design. However, innovations in either new materials or new processing technologies can seldom be successful without a synergistic combination. We demonstrate an in situ design approach to make alloys spatially modulated in concentration by using laser-powder bed fusion. We show that the partial homogenization of two dissimilar alloy melts­Ti-6Al-4V and a small amount of 316L stainless steel­allows us to produce micrometer-scale concentration modulations of the elements that are contained in 316L in the Ti-6Al-4V matrix. The corresponding phase stability modulation creates a fine scale­modulated ß + α' dual-phase microstructure that exhibits a progressive transformation-induced plasticity effect, which leads to a high tensile strength of ~1.3 gigapascals with a uniform elongation of ~9% and an excellent work-hardening capacity of >300 megapascals. This approach creates a pathway for concentration-modulated heterogeneous alloy design for structural and functional applications.

Energy Efficient SWIPT Based Mobile Edge Computing Framework for WSN-Assisted IoT.

With the increasing deployment of IoT devices and applications, a large number of devices that can sense and monitor the environment in IoT network are needed. This trend also brings great challenges, such as data explosion and energy insufficiency. This paper proposes a system that integrates mobile edge computing (MEC) technology and simultaneous wireless information and power transfer (SWIPT) technology to improve the service supply capability of WSN-assisted IoT applications. A novel optimization problem is formulated to minimize the total system energy consumption under the constraints of data transmission rate and transmitting power requirements by jointly considering power allocation, CPU frequency, offloading weight factor and energy harvest weight factor. Since the problem is non-convex, we propose a novel alternate group iteration optimization (AGIO) algorithm, which decomposes the original problem into three subproblems, and alternately optimizes each subproblem using the group interior point iterative algorithm. Numerical simulations validate that the energy consumption of our proposed design is much lower than the two benchmark algorithms. The relationship between system variables and energy consumption of the system is also discussed.

A nano interlayer spacing and rich defect 1T-MoS2 as cathode for superior performance aqueous zinc-ion batteries.

Aqueous Zn-ion batteries (ZIBs) are considered very promising alternatives to lithium-ion batteries. However, the low reversibility and slow diffusion of zinc ions in the positive electrode limit their commercial applications. Herein, we successfully prepared the metallic 1T phase of MoS2 (1T-MoS2) with a nano interlayer spacing of 1.025 nm through a simple one-step hydrothermal method, and used it as a cathode in ZIBs. By adjusting the hydrothermal temperature, the crystallinity and Zn2+ storage capacity of MoS2 as a cathode for ZIBs are effectively improved. MoS2 had the most favorable structure when the hydrothermal temperature was 200 °C, such as larger layer spacing and more lattice distortion. When employed as a cathode, 200-MoS2 exhibited a considerable specific capacity of 125 mA h g-1 at the current density of 2 A g-1 and high capacity retention of 100% after 500 cycles. This strategy provides a new option for improving the performance of the layered structure as an aqueous zinc ion battery.

Regularized slanted-edge method for measuring the modulation transfer function of imaging systems.

The slanted-edge method for modulation transfer function (MTF) measurement uses edge target images whose gray values are often affected by noise and other factors, decreasing its accuracy. We first analyze the ill-posedness in the edge spread function (ESF) regression caused by noise. Second, we propose a regularized slanted-edge method to solve this problem by incorporating a Tikhonov regularization term. Combined with varying precision weights, the ESF is solved using the variational principle, and the MTF is estimated using the regularized ESF. The regularized slanted-edge method is verified for Gaussian, gamma, and Rayleigh noise. The results show that our method improves the accuracy by 0.01-9.02% and 4.33% on average. The proposed method is more robust to noise and accurate than the slanted-edge method.

Concept and modeling analysis of a high fidelity multimode deformable mirror.

Conventional deformable mirrors (DM) cannot meet the requirement of aberration controlling for advanced lithography tools. This paper illustrates an approach using the property that deformation of a thin plate is similar to optical modes to realize a high fidelity multimode deformable mirror whose deformation has characteristics of optical aberration modes. The way to arrange actuators is also examined. In this paper, a 36-actuator deformable mirror is taken as an example to generate low-order Zernike modes. The result shows that this DM generates the fourth fringe Zernike mode (Z4) defocus, and primary aberration Z5-Z8 with an error less than 0.5%, generates the fifth-order aberration Z10-Z14, and generates the seventh-order aberration Z17-Z20 with an error less than 1.1%. The high fidelity replication of the Zernike mode indicates that the DM satisfies the demand of controlling aberrations corresponding to the first 20 Zernike modes in an advanced lithography tool.