Patescibacteria, also known as the candidate phyla radiation (CPR), are a diverse group of bacteria that constitute a disproportionately large fraction of microbial dark matter. Its few cultivated members, belonging mostly to Saccharibacteria, grow as epibionts on host Actinobacteria. Due to a lack of suitable tools, the genetic basis of this lifestyle and other unique features of Patescibacteira remain unexplored. Here, we show that Saccharibacteria exhibit natural competence, and we exploit this property for their genetic manipulation. Imaging of fluorescent protein-labeled Saccharibacteria provides high spatiotemporal resolution of phenomena accompanying epibiotic growth, and a transposon-insertion sequencing (Tn-seq) genome-wide screen reveals the contribution of enigmatic Saccharibacterial genes to growth on their hosts. Finally, we leverage metagenomic data to provide cutting-edge protein structure-based bioinformatic resources that support the strain Southlakia epibionticum and its corresponding host, Actinomyces israelii, as a model system for unlocking the molecular underpinnings of the epibiotic lifestyle. 

Genetic manipulation of Patescibacteria provides mechanistic insights into microbial dark matter and the epibiotic lifestyle

Anion-hosting cathodes capable of reversibly storing large-size anions play a leading role in dual-ion batteries (DIBs). The purpose of the present review is to summarize the most promising anion-hosting cathodes for current and late-stage DIBs. This review first summarizes the developments in conventional graphite cathodes, especially the latest advances in the graphite-related research. Next, organic cathodes for the anion storage are discussed, including aromatic amine polymers, heterocyclic polymers, bipolar compounds, and all-carbon-unsaturated compounds. Then, the review focuses on the conversion-type cathodes with high theoretical specific capacities. Finally, the future research directions of the cathodes of DIBs are proposed. 

Anion-hosting cathodes for current and late-stage dual-ion batteries

Abstract Aqueous zinc-ion batteries (AZIBs) are one of the most compelling alternatives of lithium-ion batteries due to their inherent safety and economics viability. In response to the growing demand for green and sustainable energy storage solutions, organic electrodes with the scalability from inexpensive starting materials and potential for biodegradation after use have become a prominent choice for AZIBs. Despite gratifying progresses of organic molecules with electrochemical performance in AZIBs, the research is still in infancy and hampered by certain issues due to the underlying complex electrochemistry. Strategies for designing organic electrode materials for AZIBs with high specific capacity and long cycling life are discussed in detail in this review. Specifically, we put emphasis on the unique electrochemistry of different redox-active structures to provide in-depth understanding of their working mechanisms. In addition, we highlight the importance of molecular size/dimension regarding their profound impact on electrochemical performances. Finally, challenges and perspectives are discussed from the developing point of view for future AZIBs. We hope to provide a valuable evaluation on organic electrode materials for AZIBs in our context and give inspiration for the rational design of high-performance AZIBs. 

Unveiling Organic Electrode Materials in Aqueous Zinc-Ion Batteries: From Structural Design to Electrochemical Performance

Organic materials are widely used in various energy storage devices due to their renewable, environmental friendliness and adjustable structure. Dual-ion batteries (DIBs), which use organic materials as the electrodes, are an attractive alternative to conventional lithium-ion batteries for sustainable energy storage devices owing to the advantages of low cost, environmental friendliness, and high operating voltage. To date, various organic electrode materials have been applied in DIBs. In this review, we present the development of DIBs with a following brief introduction of characteristics and mechanisms of organic materials. The latest progress in the application of organic materials as anode and cathode materials for DIBs is mainly reviewed. Finally, we also discussed the challenges and prospects of organic electrode materials for DIBs.

Organic Electrode Materials for Dual-Ion Batteries.

Organic electrode active materials are widely used in the research of electrochemical energy storage devices due to their advantages of low cost, friendly environment, strong sustainability, flexible design and high electrical activity. Although organic active materials (OAMs) are widely studied in organic and aqueous batteries, there are still some challenges to overcome before large-scale commercialization. In this paper, the reaction mechanism of OAM was reviewed, and the application of OAMs including small molecule, polymer and coordination compound in organic battery and aqueous battery and the strategy of improving electrochemical performance were introduced. Finally, the key problems and future research directions of the application of OAMs in batteries were put forward. 

Organic Active Materials in Rechargeable Batteries: Recent Advances and Prospects

A novel small organic molecule namely N,N’-bis(2-anthraquinone)-dihydrophenazine (DAQ-DPZ, 270 mAh/g) with n-p-n molecular heterojunction configuration is designed as the bipolar electrode material for Li-dual-ion batteries. To delay the dissolution for small-molecule organic electrodes, DAQ-DPZ is further coated by a protective carbon layer (DAQ-DPZ@C) through the process called surface self-carbonization. As expected, the resulting DAQ-DPZ@C can show the peak discharge capacity of 269 mAh/g and high median potential of 2.62 V in 1.6–4.4 V (vs. Li+/Li), corresponding to the peak energy density of 704 Wh kg−1 in Li-dual-ion half cells. Furthermore, DAQ-DPZ@C in the symmetric Li-dual-ion batteries can deliver the peak discharge capacity of 88 mAh/gcathode and the peak energy density of 113 Wh kg-1cathode, stably running for over 5000 cycles. To the best of our knowledge, these results are the top ones for small-molecule organic bipolar electrodes in the symmetric Li-dual-ion batteries. 

Carbon-coating small-molecule organic bipolar electrodes for symmetric Li-dual-ion batteries

A non-flammable potassium-ion battery is constructed by using an advanced n-type organic cathode called 2PTCDA@C and K-metal anode in triethyl phosphate electrolyte, which can show the peak discharge capacity of 125 mAh g−1cathode in 1.5–3.5 V and stably run for 100 cycles. 

An organic cathode in non-flammable phosphate electrolyte for K-ion batteries

In the January 2015 issue of PNAS, He et al. reported the isolation and characterization of the first Saccharibacteria (formerly known as TM7) strain from the human oral cavity (1). Named Nanosynbacter lyticus TM7x—this first cultured representative of Saccharibacteria displays an intriguing biology: It has a small cell size (200 to 300 nm in diameter) with a reduced genome and enjoys an obligate epiparasitic lifestyle by living on the surface of its bacterial host. Later work from the Banfield group showed that Saccharibacteria belongs to the candidate phyla radiation (CPR), a large bacterial linage with over 70 phyla accounting for more than a quarter of microbial diversity with predicted symbiotic lifestyle similar to that of TM7x (2–4). The discovery of CPR organisms has greatly expanded the bacterial tree of life (5); however, we still have only a limited number of cultured representatives due to their recalcitrance to conventional cultivation. This severely limits exploration of the biology and ecological roles of these mysterious bacteria. Expanding cultured representatives of CPR organisms for in-depth study is essential for the illumination of this so-called "microbial dark matter." In the current issue of PNAS, Xie et al. (6) report the isolation of the first insect-associated Saccharibacteria, named Leucosynbacter cicadicola TM7i (TM7i), achieved by capturing in situ Saccharibacteria–host association guided by epicPCR (Emulsion, Paired Isolation, and Concatenation PCR). The study offers a high-throughput method for identifying candidate host bacteria, elevating our ability to cultivate CPR organisms. Furthermore, using high-resolution live cell imaging, the study also provides strong evidence demonstrating the crucial role of the CPR-encoded type IV pili (T4P) in its symbiotic lifestyle.

Culture-based approaches to studying “microbial dark matter”

Small-molecule organic cathodes face dissolution problem in potassium-ion batteries (PIBs). For the first time, an interesting and effective strategy is unveiled to resolve this trouble by designing a new soluble small-molecule organic compound namely [N,N'-bis(2-anthraquinone)]-1,4,5,8-naphthalenetetracarboxdiimide (NTCDI-DAQ, 237 mAh g-1): Through the precise manipulation of carbonization temperature and time, the molecules on the surface of NTCDI-DAQ particles can be transformed into the amorphous carbon with the controllable thickness. This strategy called surface self-carbonization can form a carbon protective layer on organic cathodes and significantly increase their insolubility against liquid electrolytes without affecting the electrochemical behaviors of bulk particles. As a result, the as-obtained NTCDI-DAQ@C sample displays significantly improved cathode performance in PIBs. In half cells, NTCDI-DAQ@C shows superior capacity stability of 84% to 35% of NTCDI-DAQ during 30 cycles under the same conditions. In the full cells with KC8 anode, NTCDI-DAQ@C delivers a peak discharge capacity of 236 mAh g-1cathode and a high energy density of 255 Wh kg-1cathode in 0.1-2.8 V, maintaining 40% capacity retention during 3000 cycles at 1 A g-1. To the best of our knowledge, the integrated performance of NTCDI-DAQ@C is the best one among the soluble organic cathodes reported in PIBs.

Small-molecule Organic Cathodes with Carbon Coating for Highly Efficient Potassium-ion Batteries.

An organic bipolar polymer electrode called poly[anthraquinone‐alt‐dihydrophenazine] (PAD) is in situ synthesized between the two‐electron n‐type unit of dibromoanthraquinone and two‐electron p‐type unit of dihydrophenazine on the layered MXene nanosheets, leading to the formation of the material composition called PAD@MX. PAD@MX shows almost the same redox mechanism and electrode performance in Na/K‐based batteries. In Na/K‐based half cells, PAD@MX can show the peak discharge capacities of 240/255 mAh g−1 and peak energy densities of 511/597 Wh kg−1, respectively, which are among the top results for cathodes in the world. Furthermore, the Na/K‐based dual‐ion symmetric batteries can be simultaneously constructed by using PAD@MX as the single electrode material. Both symmetric batteries fulfill the “ready‐to‐charge” property without any pre‐activation. Therein, PAD@MX delivers the reversible discharge capacities of 86/104 mAh g−1cathode and energy densities of 54/64 Wh kg−1total mass, stably running for 500 cycles. To the best of our knowledge, this is the first example of organic bipolar electrodes simultaneously applied to the Na/K‐based dual‐ion symmetric batteries in the world.

Single Bipolar Polymer Electrode with MXene for Na/K‐Based Dual‐Ion Symmetric Batteries

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Xuesong He

Author Tools

Chat about Author