Interface coordination stabilizing reversible redox of zinc for high-performance zinc-iodine batteries

Aqueous Zn batteries (AZBs) have attracted extensive attention due to good safety, cost-effectiveness, and environmental benignity. However, the sluggish kinetics of divalent zinc ion and the growth of Zn dendrites severely deteriorate the cycling stability and specific capacity. The authors demonstrate modulation of the interfacial redox process of zinc via the dynamic coordination chemistry of phytic acid with zinc ions. The experimental results and theoretical calculation reveal that the in-situ formation of such inorganic–organic films as a dynamic solid-electrolyte interlayer is efficient to buffer the zinc ion transfer via the energy favorable coordinated hopping mechanism for the reversible zinc redox reactions. Especially, along the interfacial coating layer with porous channel structure is able to regulate the solvation structure of zinc ions along the dynamic coordination of the phytic acid skeleton, efficiently inhibiting the surface corrosion of zinc and dendrite growth. Therefore, the resultant Zn anode achieves low voltage hysteresis and long cycle life at rigorous charge and discharge circulation for fabricating highly robust rechargeable batteries. Such an advanced strategy for modulating ion transport demonstrates a highly promising approach to addressing the basic challenges for zinc-based rechargeable batteries, which can potentially be extended to other aqueous batteries

Interface coordination regulation of zinc ions for advanced zinc-iodine batteries

Aqueous rechargeable zinc-iodine batteries, as an alternative to lithium-ion batteries (LIBs), deliver the advantages of high theoretical specific capacity, high safety, environmental friendliness, and abundant reserves, making them suitable for large-scale energy storage applications. Nevertheless, unstable Zn anodes would cause a series of symptoms, such as the growth of Zn dendrites and side reactions, which endanger the stability and lifespan of the batteries. Herein, an organic-metal (PAA-Zn) functional film is introduced onto the surface of Zn foil via the coordination of polyacrylic acid and divalent ions to address the above challenges of Zn anodes. The PAA-Zn functional films adjust the uniform distribution of the interfacial electric field, which is advantageous for uniform Zn plating/stripping. Additionally, the abundant oxygen-containing functional groups not only significantly enhance the interfacial hydrophilicity, but also reduce the number of free water molecules reaching the Zn foil surface through the isolation and desolvation effect of functional groups, thus inhibiting corrosion and hydrogen evolution side reactions. As a result, PAA-Zn electrodes exhibited a stable cycling for over 1000 h in symmetrical cells. Most importantly, the Zn-I2 batteries demonstrated a high specific capacity with a retention rate of 89.9 % during 3500 cycles when assembled with PAA-Zn anodes

A Single Pilot Subcarrier-Based Sampling Frequency Offset Estimation and Compensation Algorithm for Optical IMDD OFDM Systems

A sampling frequency offset (SFO) estimation and compensation scheme for asynchronous optical intensity-modulation and direct-detection orthogonal frequency division multiplexing (OFDM) systems by using one single pilot subcarrier is proposed. Experimental demonstrations are also under taken to evaluate the performance of the mentioned scheme, and results show that precise SFO estimation with an accuracy of <; ±0.2 ppm can be achieved under the SFO range from -1000 to 1000 ppm after 25 km standard single mode fiber (SSMF) transmission. Meanwhile, an SFO compensation method by extending the channel response with the phase shift correction term is also presented; more than 1000 and 400 ppm SFO effects can be compensated by using the phase shift correction term and its approximation, respectively

Physical layer abstraction utilizing OSNR montioring based on deep neural network

We demonstrate a deep neural network (DNN) trained with amplitude histograms (AHs) for optical performance monitoring in a 28-GBd PAM4 based direct detection system. Both simulation and experimental results shows DNN can successfully estimate OSNRs

Cell Density Detector Based on Light Beam Focusing

Although the lab-on-a-chip system has been successfully applied in a wide variety of fields, the goal of achieving a cell counter with simple operation, low cost, and high accuracy still attracts continuous research efforts. In this paper, the authors explore a cell counter based on light beam focusing to measure the density of adherent cells. In this sensor, the light emitted from the optical fibers is collimated by the collimating lens formed in polydimethylsiloxane (PDMS). The uniformly attached adherent cells act as a convex lens, focusing the collimated light propagated through them. The intensity of the focused light indicates the density of the adherent cells. For Hela cells, a detection limit of 8.3 × 104 cells/mL with a detection range from 0.1 × 106 cells/mL to 1.0 × 106 cells/mL is achieved. This sensor is particularly useful for drug screening, cell pathology analysis, and cancer pre-diagnosis