Electrode Materials For Rechargeable Batteries Research Articles

Triazacoronene‐Based 2D Conductive Metal–Organic Framework for High‐Capacity Lithium Storage

Abstract2D conductive metal–organic frameworks (2D c‐MOFs) have attracted increasing attention as promising electrode materials for rechargeable batteries due to their designable periodic motifs, large specific surface areas, and prominent electrical conductivity. However, the development of 2D c‐MOF electrode materials with functionality remains a significant challenge because of the limited electroactive ligand motifs available. Herein, a hexahydroxy‐substituted triazacoronene ligand (6OH‐TAC) is deliberately designed and synthesized, which coordinates with Cu2+ ions to form an unprecedented 2D c‐MOF (Cu‐TAC) with functionality sites of efficient lithium storage. The synergistic effect of TAC and CuO4 enables Cu‐TAC as an anode for lithium‐ion batteries with a superior reversible capacity of 772.4 mAh g−1 at 300 mA g−1, remarkable rate performance, and outstanding long‐term cyclability (83% capacity retention at 300 mA g−1 for 600 cycles). These metrics outperform almost all 2D c‐MOF‐based electrodes, shedding light on new opportunities for energy storage devices.

Research progress on lignin-based carbon electrode materials in rechargeable batteries

Lignin, with its carbon content of up to 60%, can be an ideal precursor for the preparation of carbon materials. Carbonaceous materials obtained from lignin can be transformed into porous and structural morphologies at different scales, providing a biomass approach to energy conversion and storage in batteries. Focusing on lignin-derived carbon materials, this paper summarizes the different morphologies and structures of lignin-based carbon obtained through different preparation methods, and the different electrochemical properties exhibited by these materials as electrode materials for rechargeable batteries (lithium-ion batteries, sodium-ion batteries, lithium-sulphur batteries, etc.). In addition, the development prospects and challenges of lignin-based carbon materials in the field of rechargeable batteries are summarized, providing ideas for the next step in the design and development of high-performance lignin-based carbon-based electrode materials.

Redox-Active High-Performance Polyimides as Versatile Electrode Materials for Organic Lithium- and Sodium-Ion Batteries.

Organic electrode materials for rechargeable batteries show great promise for improving the storage capacity, reducing production costs, and minimizing environmental impact toward sustainability. In this study, we report a series of newly synthesized arylamine-based polyimides, TPPA-PIs, with three different bridge functionalizations on the imide rings and isomeric constituents that can work as versatile battery electrodes. As a lithium-ion battery cathode, a maximum energy density of 248 Wh kg-1 with high voltage operation up to 4.0 V can be achieved. As a lithium-ion battery anode, the TPPA-PIs showed a reversible storage capacity of 806 mA h g-1 at 100 mA g-1 current density with good rate capability up to a current density of 2000 mA g-1. Moreover, when applied as sodium-ion battery anodes, TPPA-PIs delivered an optimum specific capacity of up to 218 mA h g-1 after 50 cycles at a 50 mA g-1 current density and revealed a long cycling stability up to 1000 cycles under a high current density of 1000 mA g-1. More importantly, these electrochemical performances of TPPA-PIs are among the best compared with other reported polymer-based electrodes. The mechanistic studies show that both bridge functionalization on the imide units and isomerism impact the electrochemical performance by regulating their intrinsic properties such as charge storage behavior, ion diffusivity, and activation energy. We believe that such a detailed study of the structural design to electrochemical performance of these polymeric electrodes will offer insights into materials development and optimization for next-generation multifunctional energy storage devices in a wide range of applications.

Nanostructured Porous Polymer with Low Volume Expansion, Structural Distortion, and Gradual Activation for High and Durable Lithium Storage.

Organic compounds exhibit great potential as sustainable, tailorable, and environmentally friendly electrode materials for rechargeable batteries. However, the intrinsic defects of organic electrodes, including solubility, low ionic conductivity, and restricted electroactivity sites, will inevitably decrease the cycling life and capacity. We herein designed and prepared nanostructured porous polymers (NPP) with a simple one-pot method to overcome the above defects. Theoretical calculations and experimental results demonstrate that the as-synthesized NPP exhibited low volume expansion, molecular-structural distortion, and a gradual function activation process during cycling, thus exhibiting superior, high, and durable lithium storage. The gradual molecular distortion during the lithium storage processes provides more redox-active sites for Li storage, increasing the Li-storage capacity. Ex situ spectrum studies reveal the redox reaction mechanism of Li storage and demonstrate a gradual activation process during the repeated charging/discharging until the full storage of 18 Li ions is achieved. Additionally, a real-time observation on the NPP anode by in situ transmission electron microscope reveals a slight volume expansion during the repeating lithiation and delithiation processes, ensuring its structural integrity during cycling. This quantitative work for high-durability lithium storage could be of immediate benefit for designing organic electrode materials.

Influence of alkali metal ions (Li+, Na+, and K+) on the redox thermodynamics and kinetics of organic electrode materials for rechargeable batteries

Organic electrode materials have been widely applied in rechargeable Li, Na, and K batteries. However, one of the key scientific issues—the influence of Li+, Na+, and K+ ions on the redox thermodynamics and kinetics is still unclear. Herein, by using n-type poly(anthraquinonyl sulfide) (PAQS) and polyimide (PI) and p-type polytriphenylamine (PTPAn) as examples, we have systematically and deeply studied this problem though elaborate electrochemical tests and theoretical calculations. By employing three-electrode cells, the thermodynamic potentials of Li, Na, K metal electrodes as well as the PAQS, PI, and PTPAn organic electrodes have been accurately measured. They follow the order of Li+ > Na+ > K+ for PAQS and PI, and keep unchanged for PTPAn. As an application of this discovery, PAQS–PTPAn dual-ion full-cells show the highest output voltage and low-temperature performance with K+ ion. To explain the tendency, universal thermodynamic models have been established and the theoretical calculations reveal that with the increase of ionic radius, the interactions of metal ion with electrolyte solvent and discharged n-type organic (N–) become weaker, which lower down the thermodynamic potential and enhance the redox kinetics. This work provides a significant guidance for the design of high-performance organic batteries.

Small-molecule organic electrode materials for rechargeable batteries

Small-molecule organic electrode materials for rechargeable batteries

Engineering a hierarchical reduced graphene oxide and lignosulfonate derived carbon framework supported tin dioxide nanocomposite for lithium-ion storage

Tin dioxide (SnO2) is widely recognized as a high-performance anode material for lithium-ion batteries. To simultaneously achieve satisfactory electrochemical performances and lower manufacturing costs, engineering nano-sized SnO2 and further immobilizing SnO2 with supportive carbon frameworks via eco-friendly and cost-effective approaches are challenging tasks. In this work, biomass sodium lignosulfonate (LS-Na), stannous chloride (SnCl2) and a small amount of few-layered graphene oxide (GO) are employed as raw materials to engineer a hierarchical carbon framework supported SnO2 nanocomposite. The spontaneous chelation reaction between LS-Na and SnCl2 under mild hydrothermal condition generates the corresponding SnCl2@LS sample with a uniform distribution of Sn2+ in the LS domains, and the SnCl2@LS sample is further dispersed by GO sheets via a redox coprecipitation reaction. After a thermal treatment, the SnCl2@LS@GO sample is converted to the final SnO2/LSC/RGO sample with an improved microstructure. The SnO2/LSC/RGO nanocomposite exhibits excellent lithium-ion storage performances with a high specific capacity of 938.3 mAh/g after 600 cycles at 1000 mA g−1 in half-cells and 517.1 mAh/g after 50 cycles at 200 mA g−1 in full-cells. This work provides a potential strategy of engineering biomass derived high-performance electrode materials for rechargeable batteries.

Fluorine‐Rich Covalent Organic Framework to Boost Electrochemical Kinetics and Storages of K+ Ions for Potassium‐Ion Battery

AbstractCovalent organic frameworks (COFs), featuring ordered nanopores with numerous accessible redox sites, have drawn much attention as promising electrode materials for rechargeable batteries. Thus far, however, COF‐based battery electrodes have exhibited limited capacity and unsatisfactory cycling stability due to the unwanted side reactions over their large surface area. Herein, a fluorine‐rich covalent organic framework (F‐COF) as an electrode material with improved stability and performance for potassium‐ion batteries is developed. The fluorinated COF not only stabilizes intercalation kinetics of K+ ions but also reinforces its electron affinity and conductivity, improving the reversibility of bond transitions during discharge–charge cycles. As a result, F‐COF affords a high specific capacity (95 mAh g−1 at fast rates up to 5 C) and excellent cycling stability (5000 cycles with ≈99.7% capacity retention), outperforming the pristine COF‐based electrodes devoid of F atoms. Notably, the experimental capacity of F‐COF approaches its theoretical value, confirming that a large proportion of electroactive sites are being actively utilized. Altogether, this work addresses the significant role of F atoms in improving the K+‐ion storage capability of COFs and provides the rational design principles for the continued development of stable and high‐performance organic electrode materials for energy storage devices.

A Review of Nb2CTx MXene as an Emerging 2D Material: Synthesis, Applications in Rechargeable Batteries and Supercapacitors, Progress, and Outlook

Layered two-dimensional (2D) transition metal nitrides/carbides/carbonitrides are collectively known as MXenes. MXenes are the most explored candidates in the family of 2D materials due to their extraordinary physicochemical properties, which have proved to be beneficial for multifunctional applications, most likely in electrochemical energy storage, energy generation, sensing, photocatalysis, etc. In the MXene family, niobium carbide (Nb2CTx) is an emerging novel member finding suitable applications due to its unique properties, although a smaller number of research studies have been conducted on this particular MXene to date and are still in their infancy. The Nb2CTx MXene has attracted great scientific attention among the various available non-titanium-based MXenes. A detailed review on the peculiar characteristics and prominent energy applications of this novel 2D material is lacking in the literature. This has motivated us to present a review article that provides an outline on the synthesis and exemplary energy applications of Nb2CTx MXene based materials, particularly for rechargeable batteries and supercapacitors. A brief description of the crystal structure and properties of the Nb2CTx MXene is included. By understanding the physics and chemistry of the Nb2CTx MXene, the properties can be tailored suitable for specific applications. This review proclaims that Nb2CTx MXene based materials can be a future efficient electrode material for rechargeable batteries and supercapacitors.

Application of 2D MXene in Organic Electrode Materials for Rechargeable Batteries: Recent Progress and Perspectives

AbstractOrganic electrode materials (OEMs) are emerging green power because of the promising advantages such as environmental friendliness, abundant sources, easy recycling, and structural diversity. However, several inherent issues, including low electronic conductivity, dissolution of active materials, and particle pulverization restrict their practical application. MXene, as a novel 2D material has exhibited enormous potential to solve the issues of OEMs due to its high conductivity, unique structure, exceptional mechanical property, and abundant surface groups. Up to now, various effective strategies have been presented and achieved positive effects, such as constructing heterojunction structures, in situ assembly, dip‐coating, preparing free‐standing MXene paper, etc. Nonetheless, comprehensive review of the progress and status is rare. Herein, an overview of the application of MXene in organic electrode materials for rechargeable batteries is systematically put forward. Meanwhile, recent progress and future development directions are presented. This review can serve as a guide for future research.

Recent Advances in the Fabrication and Functionalization of Nanostructured Carbon Spheres for Energy Storage Applications

The development of energy storage devices providing high energy and power densities and long-term stability will play an important role in the future utilization of sustainable energy sources. Numerous efforts have been devoted to achieving these requirements, especially the design of advanced electrode materials. For this reason, there is growing interest in the innovation of new carbon-based materials with enhanced electrochemical performance. Nanostructured carbon spheres (CSs) have attracted significant attention due to their prominent properties, such as high surface area, excellent electrical conductivity, tunable porosity, and surface functionality. This review offers a comprehensive overview into the recent advances of nanostructured CSs within the last five years, focusing on synthetic strategies for producing carbon particles with precisely controlled morphologies and interior structures, as well as the potential applications of these particles as high-performance electrode materials in rechargeable batteries and supercapacitors. The challenges and perspectives on future research directions are highlighted, focusing on the controlled synthesis and functionalization of nanostructured CSs with tunable structures and properties that are well-suited to practical applications. This review is intended to serve as a helpful resource to researchers involved in the fabrication of new CS materials and the development of methods to control their structure and morphology.

Applications of In Situ Raman Spectroscopy on Rechargeable Batteries and Hydrogen Energy Systems

AbstractThe rapid growth of the economy promotes the increasing demand for energy, which accelerates resource shortage and environmental pollution issues caused by fossil fuel combustion. Electrochemical energy conversion and storage (EECS) techniques such as rechargeable batteries, fuel cells, and water electrolysis have provided promising solutions for addressing these issues. However, their further electrochemical performance improvement is still challenging due to the lack of understanding of their reaction mechanisms. Therefore, in situ tracking these electrochemical processes to capture the intermediates for mechanism verification is significant. In this review, recent work on in situ Raman spectroscopy applications on EECS systems is summarized with emphasis on the intermediates capturing capability of this technique for reaction mechanism elucidation. We aim to elucidate the underlying reaction mechanism to provide guidelines for the design of high‐efficiency electrocatalysts for fuel cells and water electrolysis and the advanced electrode materials for rechargeable batteries

Atomic-level understanding on progressive lithiation of few-layer MoS2 with surface vacancies

Vacancy engineering is a powerful modification strategy to elevate the electrochemical performance of electrode materials. In this work, the impacts of various surface vacancies in few-layer molybdenum disulfide (MoS2) on Li adsorption/intercalation and diffusion at both MoS2 surface and interlayers are systematically investigated to advance the material performance using first-principles calculations. The results show that the surface vacancy in few-layer MoS2 is easier to form than internal ones, and surface single S vacancy (VS) is the most stable. All seven surface vacancies can promote Li adsorption and intercalation at MoS2 surface and interlayer, and have a much more beneficial role on Li surface adsorption than interlayer intercalation. Surface single Mo vacancy (VMo) can upgrade the diffusion rate of Li at the few-layer MoS2 surface and nearby interlayer, and VS has a neglected impact on the rate capability. VMo is found to be the most propitious vacancy type for Li binding and diffusion at the few-layer MoS2. This theoretical exploration can help the comprehension of the impact of vacancies on the Li adsorption, intercalation, and transportation at the surface and interlayers of the dichalcogenides as high-performance electrode materials for rechargeable batteries.

Synthesis of D-A-Type Polymers Containing Thieno[3,2-b]thiophene Unit, Their Composites with Carbon, and Lithium Storage Performance as Anode Materials

Conjugated organic polymers have attracted extensive attention due to their light weight, mechanical flexibility, and structural diversity. However, poor electronic conductivity limits their application in the electrodes of lithium-ion batteries (LIBs). In this paper, two composites of D-A (donor-acceptor) polymer and activated carbon (AC)—PTPP@AC and PTPTD@AC—were designed and successfully prepared using thieno[3,2-b]thiophene (BTh) as the donor unit, benzo [1,2-b:6,5-b′] dithiophene-4,5-dione or 7a,11a-Dihydro-3,4-dithia-7,12-diaza[a,c]anthracene as the acceptor unit and AC as the substrate. PTPP@AC and PTPTD@AC were then studied as anode materials for LIBs. The successful preparation of the target products was demonstrated by FT-IR, Raman spectra, XRD, and XPS. Electrochemical properties, such as the specific capacity, cycling stability, and rate performance of the electrode materials, were tested by cyclic voltammetry and galvanostatic charge–discharge (GCD). The storage process of lithium ions was investigated by XPS and CV tests. Compared with PTPP@AC, PTPTD@AC had a higher reversible specific capacity (247.3 mAh g−1 after 300 cycles at 0.1 A g−1), a better rate performance (at 1 A g−1, specific capacity of 87.3 mAh g−1), and a higher long-term cycling performance (after 1000 cycles of 0.5 A g−1, the specific capacity remains at 146.6 mAh g−1). The better electrochemical performance of PTPTD compared to PTPP was due to the former’s significantly higher HOMO (highest occupied molecular orbital) energy level than that of PTPP, while the Eg of PTPTD was smaller than that of PTPP. The experimental results show that D-A conjugated polymers have great potential for applications as electrode materials for rechargeable batteries.

Electrolyte initiated instaneous in-situ chemical polymerization of organic cathodes for ultralong-cycling magnesium ion batteries

Redox-active organic compounds are promising electrode materials for rechargeable batteries owing to their diverse structures, light weight, resource recyclability and low cost, but the solubility and side reactions in electrolytes impede their practical applications. Herein, we report that pyrrole-based redox-active organic monomers can be instantly converted into π-conjugated polymer derivatives via a convenient and efficient in-situ chemical polymerization method during battery assembly without tedious fabrication procedures, which, in essence, is to use the electrolyte originally containing bis(hexamethyldisilazido)magnesium (Mg(HMDS)2) to induce the instantaneous in-situ polymerization of 2-pyrrolanthraquinone (2-PyAQ). Benefited from the intrinsic high ionic mobility and minimal electrolyte solubility of the redox-active π-conjugated polymer chains, the as-obtained poly(N-anthraquinoyl pyrrole) (PAQPy) cathode material exhibit high specific capacity, good rate performance and ultralong cycling stability over 4,000 cycles (with a capacity decay rate of only 0.00098% per cycle). Electrochemical kinetics analyses revealed a high Mg-ion diffusivity in the order of 10−11 cm2 s−1 and a high total capacity originated from both capacitive and diffusion-controlled contributions. A series of in-situ and ex-situ spectroscopic studies verified an extraordinary dual-ion storage mechanism based on both the insertion/extraction processes of Mg2+ and MgCl+ cations on anthraquinone side groups and the doping/de-doping processes of HMDS- anions on polypyrrole chains. This work demonstrates an effective and universal stabilization strategy of redox-active organic electrode materials via electrolyte initiated in-situ chemical polymerization to propel the exploration of high-performance secondary batteries.

Multi-heterostructured SnO2/SnSx embedded in carbon framework for high-performance sodium-ion storage.

Heterostructure materials, as newborn electrode materials for rechargeable batteries, are attracting increasing attention due to their robust architectures and superior electrochemical performances. It is widely believed that the inner electric field induced at the interface can improve the electric conductivity and ion diffusion kinetics, thus enhancing the long-term stability and high-rate performance of the batteries. Although much progress is made on heterostructure construction, the performance of the batteries is still far from satisfying the commercial applications. In this work, a new type of SnO2/SnSx (x=1, 1.5) heterostructure embedded in carbon framework (C@SnO2/SnSx) is constructed via a facile sulfidation process. Compared to a single heterojunction, the multi-heterojunctions generated at SnO2/SnSx interface can induce an intensified built-in electric field, which promotes charge transportation and reaction kinetics of the electrode for Na-ions storage. Upon the sodiation process, the induced intensified electric field drives Na ions from Sn2S3 or SnO2 to SnS, while an inverse transportation of Na ions are accelerated upon the desodation process. As a result, C@SnO2/SnSx exhibits an outstanding reversible capacity of 510mAhg-1 after 300 cycles at 200mAg-1.

Recent Progress in Synthesis and Application of Biomass‐Based Hybrid Electrodes for Rechargeable Batteries

AbstractThe rapid growth in electronic and portable devices demands safe, durable, light weight, low cost, high energy, and power density electrode materials for rechargeable batteries. In this context, biomass‐based materials and their hybrids are extensively used for energy generation research, which is primarily due to their properties such as large specific surface area, fast ion/electron kinetics, restricted volume expansion, and restrained shuttle effect. In this review, the key advancements in the preparation of biomass derived porous carbons using different synthesis strategies and their modifications with species such as heteroatoms, metal oxides, metal sulfides, silicon, and other carbon forms are discussed. The electrochemical performances of these materials and the ion storage mechanisms in different batteries including lithium‐ion, lithium–sulfur, sodium‐ion, and potassium‐ion batteries are discussed. Special attention will be paid to the challenges in using porous biomass‐derived carbons and the current strategies employed for maximizing the specific capacity and lifetime for battery applications. Finally, the drawbacks in current technology and endeavors for the future research and development in the field to catapult the performances of the biomass derived materials in order to equip them to meet the demands of commercialization are highlighted.

Sb particles embedded in N-doped carbon spheres wrapped by graphene for superior K+−Storing performances

Antimony (Sb)-based nanocomposites have emerged as an attractive class of anode materials for potassium ion batteries as they exhibit large theoretical capacity and impressive working voltage. However, the tardy potassium ion diffusion characteristic, unstable Sb/electrolyte interphase, and huge volume variation pose a grand challenge that hinder the practical use of Sb-based anodes for potassium ion batteries. Herein, we develop a simple yet robust strategy to fabricate a three-dimensional N-doped carbon (N–C) porous microspheres and reduced graphene oxides (rGO) dual-encapsulated Sb hierarchical structures (denoted Sb@N–C/rGO), which are pursued for resolving the stubborn issues of Sb-based compounds for PIBs. As expected, such judiciously crafted Sb@N–C/rGO anode renders a set of intriguing electrochemical properties, representing a high reversible specific capacity of 586 mAh g−1 at a current density of 0.2 A g−1 after 200 cycles and excellent long-cycle stability of 358 mAh g−1 at 1.0 A g−1 after 1000 cycles. It is believed that the work can provide deep understanding and new insight to develop the alloying-type electrode materials for rechargeable batteries.

Halogen Storage Electrode Materials for Rechargeable Batteries

The ever‐increasing demand for rechargeable batteries with high energy density, abundant resources, and high safety has pushed the development of various battery technologies based on cation, anion, or dual‐ion transfer. The use of halogen storage electrode materials has led to new concept battery systems such as halide‐ion batteries (HIB) and dual‐ion batteries (DIB). This review highlights the recent progress on these electrode materials, including metal (oxy)halides, layered double hydroxides, MXenes, graphite‐based materials, and organic materials with carbon or nitrogen redox centers. The reversible electrochemical halogen storage of halide ions (e.g., F−, Cl−, and Br−), dual halogen (e.g., BrmCln and [ICl2]−), or binary halide anions (e.g., PF6−, AlCl4−, [ZnClx]2−x, and [MgClx]2−x) in the electrodes is covered. The challenges and mechanisms of halogen storage in various electrode materials in HIBs and DIBs are summarized and analyzed, providing insights into the development of high‐performance halogen storage electrode materials for rechargeable batteries.

Ethynyl functionalized porphyrin complex as a new cathode for organic alkali metal batteries with excellent cycling stability

Organic materials, featuring low cost, structural diversity, and environmental friendliness, have emerged as promising electrode materials for rechargeable batteries in recent years. However, they suffer from unstable cycling performance due to their high solubility in liquid electrolytes. Herein, we demonstrated a novel functionalized porphyrin [5,15-bis(ethynyl)- porphinato]copper(II) (CuDEP) as the stable organic cathode for organic alkali metal batteries. Owing to the in-situ electropolymerization and multiple electron transfer capability, CuDEP showed highly reversible capacity, long-term cycling stability (106 mAh/g at 1 A/g after 5000 cycles), and superior rate performance in organic lithium battery. N atoms act the charge storage sites where both cations and anions are alternatively stored during the charge and discharge. In organic sodium and potassium batteries, CuDEP cathode also demonstrated stable cycling and high rate capability. This result suggests that ethynyl group functionalized small porphyrin molecule would be a promising cathode for long-term organic alkali metal batteries for green and stable energy storage.