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AbstractLactic acid bacteria (LAB) are the main probiotics currently available in the markets and are essential for maintaining gut health. To guarantee probiotic function, it is imperative to boost the culture yield of probiotic organisms, ensure the sufficient viable cells in commercial products, or develop effective prebiotics. Recent studies have shown that protein hydrolysates and their derived peptides promote the proliferation of probiotic in vitro and the abundance of gut flora. This article comprehensively reviews different sources of protein hydrolysates and their derived peptides as growth-promoting factors for probiotics including Lactobacillus, Bifidobacterium, and Saccharomyces. We also provide a preliminary analysis of the characteristics of LAB proteolytic systems focusing on the correlation between their elements and growth-promoting activities. The structure-activity relationship and underlying mechanisms of growth-promoting peptides and their research perspectives are thoroughly discussed. Overall, this review provides valuable insights into growth-promoting protein hydrolysates and their derived peptides for proliferating probiotics in vivo or in vitro, which may inspire researchers to explore new options for industrial probiotics proliferation, dairy products fermentation, and novel prebiotics development in the future. [ABSTRACT FROM AUTHOR]

The sodium storage performance of Ge-based materials suffers from poor cycling stability caused by the volume variation and collapse of the structure during cycling process. In this work, Cu3Ge coated by nitrogen-doped carbon (Cu3Ge-NC) nanorods are prepared by annealing the mixture of CuGeO3 nanowires and polyacrylonitrile which acts as nitrogen and carbon source. As anode materials for sodium ion batteries, the outside carbon shell inhibits the serious volume change caused by Na+ insertion/extraction, and the Cu3Ge alloy enhances the sodiation capacity with rapid electron transfer and fast reaction kinetics. Corresponding kinetic analysis indicates pseudocapacitive behaviors play a dominant role in the total capacity at high rates. Hence, the Cu3Ge-NC exhibits favorable rate capability and cycling stability, which delivers a reversible capacity of 160 mAh g−1 for 500 cycles at a current density of 100 mA g−1. [ABSTRACT FROM AUTHOR]

Because of the abundant sodium resources and identical fundamental principles, sodium ion batteries (SIBs) are the state‐of‐the‐art alternative for lithium ion batteries. However, the larger ionic radius of Na+ causes sluggish reaction kinetics, which directly results in inferior electrochemical performance. In this work, the sodium storage properties of commercial bulk Sb2S3 (CSS) were improved by a single lithiation/delithiation cycle obtaining the lithium pre‐cycled Sb2S3 (LSS). Quantitative analysis reveals that the sodiation/desodiation kinetics of CSS and LSS is mainly diffusion‐controlled behavior and capacitive process, respectively. Thus, the reaction kinetics of LSS is promising, which exhibits improved initial coulombic efficiency, stable cycling performance, and high rate capability. In addition, a stable Li‐containing solid electrolyte interphase film was formed during the lithiation process, which can prevent continuous consumption of electrolyte during the each sodiation process. These results demonstrate that prelithiation technique should be a potential strategy to promote practical application for SIBs. [ABSTRACT FROM AUTHOR]

Ternary Sn‐based sulfides have been considered as potential anode materials for sodium‐ion batteries (SIBs) due to their unique composition and high theoretical specific capacities. However, such kind of materials suffers from sluggish kinetics and huge volumetric variation resulting from the large ionic size of the sodium ions during the battery operation process. Herein, we use a facile hydrothermal method to prepare Cu2SnS3/reduced graphene oxide (CTS/RGO) composite. Characterizations reveal that CTS/RGO consists of ultrafine CTS nanoparticles with uniform and small size, which are anchored uniformly on the surface of RGO sheets. Benefited from the unique structure feature, CTS/RGO has a high reversible capacity of 566.8 mA h g−1, good cycle stability and rate capability even at a high current density of 3200 mA g−1, which is superior to that of bare CTS. The improved performances are ascribed to the unique structure with anchoring ultrafine CTS nanoparticles on the surface of high conductive and flexible RGO sheets, which can greatly enhance electrochemical reaction kinetics and effectively alleviate volume effect of the active materials. [ABSTRACT FROM AUTHOR]

Metal sulfides have been considered as one of the most promising class of anode materials for lithium‐ion batteries. However, large volume change and low intrinsic electrical conductivity significantly restrict the performance. Herein, flexible electrode materials comprising ZnS nanotubes/carbon cloth are prepared by combined solvothermal and ion‐exchange sulfidation technique. The ZnS nanotube array/carbon cloth electrode is assessed for application in lithium‐ion batteries and remarkable improvement towards reversible capacity was observed. A notable capacity of 1053 mAh g−1 at 0.2 C and a maintained reversible capacity of 608 mAh g−1 after 100 cycles are observed, which are both comparable to similar materials in previously published reports. The ZnS nanotubes with small dimension and uniform dispersion grown directly on carbon cloth can effectively shorten the path of the lithium‐ions, facilitating the charge transfer of the electrode. The carbon cloth and the three‐dimensional (3D) structured carbon fiber exhibit a large surface area and can thus efficiently reduce the volume change during the discharge/charge cycles. A flexible electrode comprising ZnS nanotubes/carbon cloth is synthesized, exhibiting excellent reversibility and superior cycling stability in lithium‐ion batteries. The ZnS nanotubes grown directly on carbon cloth, effectively shorten the path for lithium‐ion transport, facilitating good charge transfer in the electrode. The 3D carbon fibre structure with a high surface area can efficiently reduce the volume change during discharge/charge cycles. [ABSTRACT FROM AUTHOR]

A novel silicon nanowire film anode was successfully prepared by a combination of magnetron sputtering deposition and metal-catalyzed electroless etching technology. Scanning electron microscopy revealed the formation of a Si film composed of nanowires with a diameter of ~70 nm and lengths of ~3.5 μm. As-prepared Si nanowire film is directly grown on current collectors without binders and carbon additives, which provides a good contact and adhesion of them to current collector. Furthermore, the defined spacing of nanoscale Si nanowire allows Si to undergo large volume change during the alloying/dealloying process without loss of its integrity. These structural features of the resulting Si nanowire make it a promising anode for lithium-ion batteries with remarkably improved electrochemical performance compared with the Si film-based electrode prepared without metal-catalyzed electroless etching process. [ABSTRACT FROM AUTHOR]

Atomically modified graphitic carbon nitride quantum dots (QDs), characterized by strongly increased reactivity and stability, are developed. These are deposited on arrays of TiO2 nanopillars used as a photoanode for the photoelectrochemical water splitting. This photoanode shows excellent stability, with 111 h of continuous work without any performance loss, which outperforms the best‐reported results by a factor of 10. Remarkably, our photoanode produces hydrogen even at zero bias. The excellent performance is attributed to the enhancement of photoabsorption, as well as to the promotion of charge separation between TiO2 nanopillars and the QDs. TiO2 nanopillars decorated with N‐defects graphitic carbon nitride quantum dots are developed for water splitting in this work. This photoanode demonstrates excellent photocatalytic stability (more than 110 h of continuous illumination without any performance loss) and produces hydrogen with a rate of 0.8525 µmol·h−1·cm−2 even at zero bias. [ABSTRACT FROM AUTHOR]

Germanium is considered as a potential anode material for sodium-ion batteries due to its fascinating theoretical specific capacity. However, its poor cyclability resulted from the sluggish kinetics and large volume change during repeated charge/discharge poses major threats for its further development. One solution is using its ternary compound as an alternative to improve the cycling stability. Here, high-purity CuGeO3 nanowires were prepared via a facile hydrothermal method, and their sodium storage performances were firstly explored. The as-obtained CuGeO3 delivered an initial charge capacity of 306.7 mAh g−1 along with favorable cycling performance, displaying great promise as a potential anode material for sodium ion batteries. [ABSTRACT FROM AUTHOR]