Covalent–Organic Frameworks: Advanced Organic Electrode Materials for Rechargeable Batteries

Covalent–organic frameworks (COFs), featuring structural diversity, framework tunability and functional versatility, have emerged as promising organic electrode materials for rechargeable batteries and garnered tremendous attention in recent years. The adjustable pore configuration, coupled with the functionalization of frameworks through pre‐ and post‐synthesis strategies, enables a precise customization of COFs, which provides a novel perspective to deepen the understanding of the fundamental problems of organic electrode materials. In this review, a summary of the recent research into COFs electrode materials for rechargeable batteries including lithium‐ion batteries, sodium‐ion batteries, potassium‐ion batteries, and aqueous zinc batteries is provided. In addition, this review will also cover the working principles, advantages and challenges, strategies to improve electrochemical performance, and applications of COFs in rechargeable batteries.     

Challenges and Emerging Opportunities in High‐Mobility and Low‐Energy‐Consumption Organic Field‐Effect Transistors

Organic field‐effect transistors (OFETs) are the basic elements of organic circuits towards flexible, printable, and wearable electronics. Low‐energy‐consumption OFETs with high mobility are the prerequisite for practical applications. After 30 years of development, OFETs have progressed rapidly, from field‐effect materials to devices, and from individual device to small‐ and medium‐scale integration. Here, a brief retrospective of OFETs' development over the past decades, and the emerging opportunities and challenges from device physics, multifunctional materials to integrated application are presented.     

In Situ Electrochemical Synthesis of MXenes without Acid/Alkali Usage in/for an Aqueous Zinc Ion Battery

The traditional method to fabricate a MXene based energy storage device starts from etching MAX phase particles with dangerous acid/alkali etchants to MXenes, followed by device assembly. This is a multistep protocol and is not environmentally friendly. Herein, an all‐in‐one protocol is proposed to integrate synthesis and battery fabrication of MXene. By choosing a special F‐rich electrolyte, MAX V₂AlC is directly exfoliated inside a battery and the obtained V₂CT_X MXene is in situ used to achieve an excellent battery performance. This is a one‐step process with all reactions inside the cell, avoiding any contamination to external environments. Through the lifetime, the device experiences three stages of exfoliation, electrode oxidation, and redox of V₂O₅. While the electrode is changing, the device can always be used as a battery and the performance is continuously enhanced. The resulting aqueous zinc ion battery achieves outstanding cycling stability (4000 cycles) and rate performance (97.5 mAh g^?1 at 64 A g^?1), distinct from all reported aqueous MXene‐based counterparts with pseudo‐capacitive properties, and outperforming most vanadium‐based zinc ion batteries with high capacity. This work sheds light on the green synthesis of MXenes, provides an all‐in‐one protocol for MXene devices, and extends MXenes’ application in the aqueous energy storage field.     

New Class of Ni‐Rich Cathode Materials Li[NixCoyB1−x−y]O2 for Next Lithium Batteries

A new class of layered cathodes, Li[Ni_xCo_yB_1?x?y]O₂ (NCB), is synthesized. The proposed NCB cathodes have a unique microstructure in which elongated primary particles are tightly packed into spherical secondary particles. The cathodes also exhibit a strong crystallographic texture in which the a–b layer planes are aligned along the radial direction, facilitating Li migration. The microstructure, which effectively suppresses the formation of microcracks, improves the cycling stability of the NCB cathodes. The NCB cathode with 1.5 mol% B delivers a discharge capacity of 234 mAh g^?1 at 0.1 C and retains 91.2% of its initial capacity after 100 cycles (compared to values of 229 mAh g^?1 at 0.1 C and 78.8% for pristine Li[Ni_0.9Co_0.1]O₂). This study shows the importance of controlling the microstructure to obtain the required cycling stability, especially for Ni‐rich layered cathodes, where the main cause of capacity fading is related to mechanical strain in their charged state.     

Double the Capacity of Manganese Spinel for Lithium‐Ion Storage by Suppression of Cooperative Jahn–Teller Distortion

The relatively low capacity and capacity fade of spinel LiMn₂O₄ (LMO) limit its application as a cathode material for lithium‐ion batteries. Extending the potential window of LMO below 3 V to access double capacity would be fantastic but hard to be realized, as it will lead to fast capacity loss due to the serious Jahn–Teller distortion. Here using experiments combined with extensive ab initio calculations, it is proved that there is a cooperative effect among individual Jahn–Teller distortions of Mn³⁺O₆ octahedrons in LMO, named as cooperative Jahn–Teller distortion (CJTD) in the text, which is the difficulty to access the capacity beyond one lithium intercalation. It is further proposed that the cationic disordering (excess Li at Mn sites and Li/Mn exchange) can intrinsically suppress the CJTD of Mn³⁺O₆ octahedrons. The cationic disordering can break the symmetry of Mn³⁺ arrangements to disrupt the correlation of distortions arising from individual JT centers and prevent the Mn³⁺? O bonds distorting along one direction. Interestingly, with the suppressed CJTD, the original octahedral vacancies in spinel LMO are activated and can serve as extra Li‐ion storage sites to access the double capacity with good reversible cycling stability in microsized LMO.     

Industrial attributes of β-glucanase produced by Bacillus sp. CSB55 and its potential application as bio-industrial catalyst

Bioprocess and Biosystems Engineering - The β-glucanase produced from Bacillus sp. CSB55 not only depicts the potent industrial characteristics but also relates as bio-industrial catalyst...     

Distinct lung microbial community states in patients with pulmonary tuberculosis

An improved understanding of the lung microbiome may lead to better strategies to diagnose, treat, and prevent pulmonary tuberculosis(PTB). However, the characteristics of the lung microbiomes of patients with TB remain largely undefined. In this study, 163 bronchoalveolar lavage(BAL) samples were collected from 163 sputum-negative suspected PTB patients. Furthermore, 12 paired BAL samples were obtained from 12 Mycobacterium tuberculosis-positive(MTB+) patients before and after negative conversion following a two-month anti-TB treatment. The V3–V4 region of the 16 S ribosomal RNA(rRNA) gene was used to characterize the microbial composition of the lungs. The results showed that the prevalence of MTB in the BAL samples was 42.9%(70/163) among the sputum-negative patients. The α-diversity of lung microbiota was significantly less diverse in MTB+ patients compared with Mycobacterium tuberculosis-negative(MTB–) patients. There was a significant difference in β-diversity between MTB+ and MTB– patients. MTB+ patients were enriched with Anoxybacillus, while MTB– patients were enriched with Prevotella, Alloprevotella, Veillonella, and Gemella. There was no significant difference between the Anoxybacillus detection rates of MTB+ and MTB– patients. The paired comparison between the BAL samples from MTB+ patients and their negative conversion showed that BAL negative-conversion microbiota had a higher α-diversity. In conclusion, distinct features of airway microbiota could be identified between samples from patients with and without MTB. Our results imply links between lung microbiota and different clinical groups of active PTB.     

Molecular phylogeny and species delimitation of Stachyuraceae: Advocating a herbarium specimen‐based phylogenomic approach in resolving species boundaries

Species concept and delimitation are fundamental to taxonomic and evolutionary studies. Both inadequate informative sites in the molecular data and limited taxon sampling have often led to poor phylogenetic resolution and incorrect species delineation. Recently, the whole chloroplast genome sequences from extensive herbarium specimen samples have been shown to be effective to amend the problem. Stachyuraceae are a small family consisting of only one genus Stachyurus of six to 16 species. However, species delimitation in Stachyurus has been highly controversial because of few and generally unstable morphological characters used for classification. In this study, we sampled 69 individuals of seven species (each with at least three individuals) covering the entire taxonomic diversity, geographic range, and morphological variation of Stachyurus from herbarium specimens for genome‐wide plastid gene sequencing to address species delineation in the genus. We obtained high‐quality DNAs from specimens using a recently developed DNA reconstruction technique. We first assembled four whole chloroplast genome sequences. Based on the chloroplast genome and one nuclear ribosomal DNA sequence of Stachyurus, we designed primers for multiplex polymerase chain reaction and high throughput sequencing of 44 plastid loci for species of Stachyurus. Data of these chloroplast DNA and nuclear ribosomal DNA internal transcribed spacer sequences were used for phylogenetic analyses. The phylogenetic results showed that the Japanese species Stachyurus praecox Siebold & Zucc. was sister to the rest in mainland China, which indicated a typical Sino‐Japanese distribution pattern. Based on diagnostic morphological characters, distinct distributional range, and monophyly of each clade, we redefined seven species for Stachyurus following an integrative species concept, and revised the taxonomy of the family based on previous reports and specimens, in particular the type specimens. Furthermore, our divergence time estimation results suggested that Stachyuraceae split from its sister group Crossosomataceae from the New World at ca. 54.29 Mya, but extant species of Stachyuraceae started their diversification only recently at ca. 6.85 Mya. Diversification time of Stachyurus in mainland China was estimated to be ca. 4.45 Mya. This research has provided an example of using the herbarium specimen‐based phylogenomic approach in resolving species boundaries in a taxonomically difficult genus.