RESUMEN
In the search for next-generation green energy storage solutions, Cu-S electrochemistry has recently gained attraction from the battery community owing to its affordability and exceptionally high specific capacity of 3350 mAh gs -1. However, the inferior conductivity and substantial volume expansion of the S cathode hinder its cycling stability, while the low output voltage limits its energy density. Herein, a hollow carbon sphere (HCS) is synthesized as a 3D conductive host to achieve a stable S@HCS cathode, which enables an outstanding cycling performance of 2500 cycles (over 9 months). To address the latter, a Zn//S@HCS alkaline-acid decoupled cell is configured to increase the output voltage from 0.18 to 1.6 V. Moreover, an electrode and electrolyte co-energy storage mechanism is proposed to offset the reduction in energy density resulting from the extra electrolyte required in Zn//S decoupled cells. When combined, the Zn//S@HCS alkaline-acid decoupled cell delivers a record energy density of 334 Wh kg-1 based on the mass of the S cathode and CuSO4 electrolyte. This work tackles the key challenges of Cu-S electrochemistry and brings new insights into the rational design of decoupled batteries.
RESUMEN
The Daniell cell (Cu vs. Zn), was invented almost two centuries ago, but has been set aside due to its non-rechargeable nature and limited energy density. However, these cells are exceptionally sustainable because they do not require rare earth elements, are aqueous and easy to recycle. This work addresses key challenges in making Daniell cells relevant to our current energy crisis. First, we propose new approaches to stabilise Zn and Cu plating and stripping processes and create a rechargeable cell. Second, we replace salt bridges with an anion exchange membrane, or a bipolar membrane for alkaline-acid hybrid Zn-Cu batteries operating at 1.56 V. Finally, we apply these changes in pouch cells in order to increase energy and power density. These combined developments result in a rechargeable Daniell cell, which can achieve high areal capacities of 5 mA h cm-2 and can easily be implemented in 1 A h pouch cells.
RESUMEN
This paper researches the compatibility of bamboo and Portland cement by measuring the hydration temperature of Portland cement. Meanwhile, bamboo shavings and Portland cement, which were utilized as main raw materials, were prepared into bamboo Portland cement particle boards through cold compression forming, so as to further verify the compatibility of bamboo and Portland cement and research the practicability of preparing bamboo Portland cement particle boards by using bamboo. Research studies show that bamboo contain water-soluble saccharides, such as polysaccharide, disaccharide, and glucose, and organic carboxylic acids, such as formic acid and acetic acid. Water-soluble saccharides are converted into saccharic acid after dissolving in water, then a saccharide-calcium complex with a pompon-like structure is formed through a reaction between saccharic acid and calcium ions of Portland cement hydrates, and the saccharide-calcium complex covers the surfaces of the cement particles and prevents further hydration of the cement, achieving a certain anticoagulation effect on Portland cement; a chelation reaction between the carboxyl of the organic carboxylic acid and the calcium ions of Portland cement hydrates takes place and the concentration of calcium ions in the hydration system is reduced, which exerts an influence on further hydration process of Portland cement and achieves a certain anticoagulation effect. Because of the poor compatibility of Portland cement and bamboo, the physical and mechanical properties of bamboo Portland cement particle boards prepared from bamboo shavings and Portland cement directly cannot meet the requirements of the national standards (GB/T24312-2009) of cement particle boards.
RESUMEN
A new trend is emerging that flexible batteries will play an indispensable role in the progress of social science and technology. However, flexibility exists only in a single direction for the existing electrode material. Searching for flexible battery materials has attracted more and more attention from researchers. In this article, the lattice structural stability, electronic structure modulation, and the Li adsorption properties of the heterostructures designed by assembling GeP3 and NbX2 (X = S, Se) together were methodically explored based on van der Waals. We found that diffusion barrier of the GeP3/NbS2 heterostructure with metallic properties is 0.21 eV for Li. It greatly improves the charge and discharge performance of the battery. The predicted heterostructure shows quite high theoretical specific capacity with 540.24 mA h/g, which is higher than the traditional graphite anode (372 mA h/g). It demonstrates superior isotropic flexibility with a considerable small Young's modulus (151.98-159.02 N/m), which has promising application as flexible electrodes for rechargeable battery equipment.
RESUMEN
A series of novel fluoropolymer anion exchange membranes based on the copolymer of vinylbenzyl chloride, butyl methacrylate, and hexafluorobutyl methacrylate has been prepared. Fourier transform infrared (FT-IR) spectroscopy and elemental analysis techniques are used to study the chemical structure and chemical composition of the membranes. The water uptake, ion-exchange capacity (IEC), conductivity, methanol permeability, and chemical stability of the membranes are also determined. The membranes exhibit high anionic conductivity in deionized water at 65 °C ranging from 3.86×10(-2) S cm(-1) to 4.36×10(-2) S cm(-1). The methanol permeability coefficients of the membranes are in the range of 4.21-5.80×10(-8) cm(2) s(-1) at 65 °C. The novel membranes also show good chemical and thermal stability. An open-circuit voltage of 0.7 V and a maximum power density of 53.2 mW cm(-2) of alkaline direct methanol fuel cell (ADMFC) with the membrane C, 1 M methanol, 1 M NaOH, and humidified oxygen are achieved at 65 °C. Therefore, these membranes have great potential for applications in fuel cell systems.