Recent Progress of Biomass-derived Carbon Materials used for Secondary Batteries

With rapid economic development, utilization of energy storage is increasingly important. Carbon materials derived from biomass are widely applied in energy storage systems due to their inexpensive and environmentally friendly nature. Compared to other advanced anode materials that have been explored, biomass carbon materials have high specific surface areas, adjustable porous structures, and heteroatoms that facilitate ion transfer and diffusion. To date, a series of porous biomass-derived carbon materials prepared through various methods have been used as anode electrodes of secondary batteries which greatly promoted their capacities. In this paper, we summarize the morphology and pore structure of biomass-derived materials from different precursors and discuss the electrochemical performance of secondary batteries (LIBs, SIBs, KIBs and ASSLMBs) equipped with biomass-derived carbon materials including monomers and composites as anode electrodes. Current research challenges along with future prospects for carbon-based electrode materials to improve secondary battery energy storage performance are emphasized

Syntheses and surface engineering of composite anodes by coating thin-layer silicon on carbon cloth for lithium storage with high stability and performance

Silicon-flexible carbon composites can achieve binder-free application and solve the problem of silicon expansion during cycles. The effective loading and dispersion of silicon onto carbon play an important role in improving the performance of anode materials. Herein, surface engineering of the hole-opening process was successfully achieved before the deposition of silicon. This resulted in fine holes on the carbon cloth, increasing the specific surface area to provide abundant confined spaces for dispersing nano-silicon. A composite structure was formed and structurally optimized by depositing an ultra-thin silicon layer in the holes of mesoporous carbon fiber cloth (DTSi/CC), improving the conductivity of the material, increasing the migration rate of lithium ions, and inhibiting the volume expansion of the anode material during the cycles. At 100 mA g–1, the fabricated half-cells achieved a reversible capacity of 1457 mA h g–1 and retained 70.9% initial capacity after 100 cycles. Even when the current density was increased to 1.0 A g–1, they boasted a capacity of 1037 mA h g–1 and had 76.8% capacity retention after 500 cycles. Free of binders and conductive additives, the DTSi/CC composite was directly used as the anode, exhibiting superior properties with high reversible specific capacity, excellent cyclic performance, and good rate capability. This study provides a straightforward, effective route to obtain high-performance silicon-based anode materials for lithium-ion batteries

In Situ Growth of a Feather‐like MnO2 Nanostructure on Carbon Paper for High‐Performance Rechargeable Sodium‐Ion Batteries

Recently, sodium‐ion batteries have attracted great attention, owing to the rich resource and low cost. In the present work, a feather‐like MnO2 nanostructure was prepared directly on carbon paper by using a rapid and simple hydrothermal route for the first time. The formation mechanism was proposed by investigating the intermediate products during the reaction. When applied as an anode for a sodium‐ion battery, the feather‐like MnO2 nanostructure on carbon paper exhibited a high discharge capacity, good rate reversibility, and long‐term cycling stability. A high specific capacity of approximately 300 mAh g−1 could be obtained even after cycling 400 times with a current density of 0.1 A g−1. Furthermore, the Na+ storage mechanism of MnO2 on carbon paper in the sodium‐ion battery was also investigated in this work. Such high performance can be attributed to the porous structure of the substrate and high specific surface area of the feather‐like nanostructure

Theoretical study of the influence of doped niobium on the electronic properties of CsPbBr3

In the family of inorganic perovskite solar cells (PSCs), CsPbBr3 has attracted widespread attention due to its excellent stability under high humidity and high temperature conditions. However, power conversion efficiency (PCE) improvement of CsPbBr3-based PSCs is markedly limited by the large optical absorption loss coming from the wide band gap and serious charge recombination at interfaces and/or within the perovskite film. In this work, using density functional theory calculations, we systemically studied the electronic properties of niobium (Nb)-doped CsPbBr3 with different concentration ratios. As a result, it is found that doped CsPbBr3 compounds are metallic at high Nb doping concentration but semiconducting at low Nb doping concentration. The calculated electronic density of states shows that the conduction band is predominantly constructed of doped Nb. These characteristics make them very suitable for solar cell and energy storage applications

CRISPR/Cas12a-based approaches for efficient and accurate detection of Phytophthora ramorum

IntroductionPhytophthora ramorum is a quarantine pathogen that causes leaf blight and shoot dieback of the crown, bark cankers and death on a number of both ornamental and forest trees, especially in North America and northern Europe, where it has produced severe outbreaks. Symptoms caused by P. ramorum can be confused with those by other Phytophthora and fungal species. Early and accurate detection of the causal pathogen P. ramorum is crucial for effective prevention and control of Sudden Oak Death.MethodsIn this study, we developed a P. ramorum detection technique based on a combination of recombinase polymerase amplification (RPA) with CRISPR/Cas12a technology (termed RPACRISPR/ Cas12a).ResultsThis novel method can be utilized for the molecular identification of P. ramorum under UV light and readout coming from fluorophores, and can specifically detect P. ramorum at DNA concentrations as low as 100 pg within 25 min at 37°C.DiscussionWe have developed a simple, rapid, sensitive, unaided-eye visualization, RPA CRISPR/Cas12a-based detection system for the molecular identification of P. ramorum that does not require technical expertise or expensive ancillary equipment. And this system is sensitive for both standard laboratory samples and samples from the field

Theoretical study of the influence of doped oxygen group elements on the properties of organic semiconductors

Organic semiconductor materials are widely used in the field of organic electronic devices due to their wide variety, low price, and light weight. However, their developments are still restrained by their low stability and carrier mobility. Density functional theory (DFT) was used to study the influence of doped oxygen group elements (O, S, Se, and Te) on the properties of organic semiconductor materials (seven-membered benzothiophene, o-pentacene, thiophene derivatives, and pentacene) in this paper. Based on the calculation of EHOMO, ELUMO, ΔE, and total energy, the performances of organic semiconductor materials without and with doped elements were compared, and it was found that the doping of multi-element Te makes the material have high stability and potential high mobility. For these studied organic semiconductor materials, when the atoms of the doped site change in the order of O, S, Se, and Te, the carrier mobility gradually increases, and the molecules show a tendency of stability. In this paper, promising doping elements and doping methods for these studied molecules are determined through calculations and screening out suitable materials more efficiently and economically without a large amount of repetitive experimental work, which may provide a theoretical basis and guidance for preparing high-performance organic semiconductor materials

Recent Progress in Perovskite Solar Cells Modified by Sulfur Compounds

In the past decade, organic–inorganic hybrid perovskite solar cells (PSCs) have begun to be increasingly studied worldwide owing to the superior properties of perovskite material. However, some issues have delayed their commercialization, such as their long-term stability, cost reduction, scale-up ability, and efficiency. The introduction of sulfur to PSCs can relieve the above issues because sulfur can passivate interfacial trap states, suppress charge recombination, and inhibit ion migration, thereby enhancing the stability of PSCs. Furthermore, Pb-S bonds provide new channels for carrier extraction. Herein, the sulfur-based compounds utilized in PSCs are summarized and classified according to their functions in the different layers of PSCs. The results indicate that these sulfur-based compounds have efficiently promoted the commercialization of PSCs. It is hoped that this review can help others understand the intrinsic phenomena of sulfur-based PSCs and motivate additional investigations