Excellent Specific Capacitance Research Articles

A green aqueous binder to enhance the electrochemical performance of Li-rich disordered rock salt cathode material

Li-rich disordered rock-salt oxides (DRX) are considered an attractive cathode material in the future battery field due to their excellent energy density and specific capacity. Nevertheless, anionic redox provides high capacity while causing O2 over-oxidation to O2, resulting in voltage hysteresis and capacity decay. Herein, the crystal structure of Li1.3Mn0.4Ti0.3O1.7F0.3 (LMTOF) cathode is stabilized by using sodium carboxymethylcellulose (CMC) binders replacing traditional polyvinylidene difluoride (PVDF) binders. The electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) reveal that the CMC-based LMTOF electrode has higher electronic conductivity and lithium-ion diffusion kinetics. Moreover, CMC has been demonstrated to improve the O2– reversibility, reduce the amounts of byproducts from electrolyte decomposition and suppress transition metal dissolution by Na+/Li+ exchange reaction. Furthermore, the CMC-based LMTOF electrode also exhibits less volume change upon lithiation/delithiation processes compared to the PVDF-based electrode, resulting in enhanced structural stability during cycling. Benefiting from these features, the CMC binders can effectively improve the cycling life and rate performance of the LMTOF cathode, and the CMC-based LMTOF electrode shows good capacity retention of 94.5 % after 30 cycles at 20 mA/g and 66.7 % after 100 cycles at 200 mA/g. This finding indicates that CMC as a binder can efficiently stabilize the structure and improve the electrochemical performance of Li-rich disordered rock-salt oxides cathode, making it possible for practical Li-ion battery applications.

Self-charging hybrid energy devices collaborated with enzymatic biofuel cells and supercapacitors

Enzymatic biofuel cells (EBFCs) are promising as a biocompatible power source for implantable and wearable devices, converting chemical energy of body fluids into electricity. However, they have intrinsic limitations, such as low power density and requirement for continuous fuel supply. To overcome the difficulties, hybrid energy devices (HEDs) that are combinative device of supercapacitor (SC) and EBFC are suggested in this study. They consist of anode and cathode including (i) enzymes reacting with respective fuels and (ii) mediators promoting transfer and storage of electrons. As EBFCs, HEDs exhibit exceptional fuel reactivity, achieving 0.91 and 0.51 mA/cm2 in glucose oxidation reaction and oxygen reduction reaction, while they play as SCs with excellent power and specific storage capacitance of 0.93 mW/cm2 and 307 mF/cm2. Moreover, HEDs show self-charging property that is uniquely observed in devices operated by the collaboration of enzyme and mediator. By this benefit, their open circuit voltage is well preserved in absent of fuels, while they can discharge even without supply of fuel. These features are obvious evidence that HEDs can be considered as advanced power sources for implantable and wearable devices.

Iron-doped cross-linked puffed carbon as capacitive anode for the enhancement of bioelectron storage capacity in microbial fuel cells

Microbial fuel cell (MFC) can utilize the metabolism of electroactive microorganisms to remove organic pollutants from wastewater, and the application of capacitive anodes can enhance the power generation capacity of MFC and the energy storage capacity of bioelectronics. This research aimed to create a capacitive anode with a large specific surface area and excellent electrical conductivity. To achieve this aim, iron-doped cross-linked puffed carbon (CPC–Fe) was prepared for the modification of carbon cloth (CC) substrates by a simple one-step expansion carbonization method using FeCl3·6H2O and maltose as raw materials. The surface structure characterization confirms the successful incorporation of Fe atoms, with Fe3O4 accounting for 79.61%. Fe3O4 exhibits excellent specific capacitance characteristics and can also serve as a good conductor for the transmission or reception of electrons generated by electroactive bacteria. Furthermore, the mesoporous volume of CPC-Fe significantly increases, which contributes to the enhancement of the specific capacitance of material and the improvement of charge storage capacity. Based on these advantages, the maximum power density of MFC equipped with CPC-Fe/CC anode reaches 1850.50 mW m−2. The CPC-Fe/CC bioanode has a cumulative total charge of 1076.02 C m−2, showing good capacitive behaviour and exhibiting a significant enrichment effect on Geobacter species. This study demonstrates that the regulation of extracellular electron transfer (EET) process based on bioelectronic reception steps can not only enhance the power generation performance of MFC, but also effectively improve the energy storage capacity of MFC, which offers significant knowledge for the development of electrode design in other bioelectrochemical systems.

Superior energy storage and stability realized in flexible carbon nanotube aerogel-metal organic framework based supercapacitor via interface engineering

Our present study unveils a new carbon nanotube aerogel-metal organic framework free-standing electrode, showcasing exceptional dual functionality as an electrode and current collector. In the prepared electrode, an interface engineering between functionalized carbon nanotubes (FCNT) and metal-organic frameworks (MOF) leads to the excellent electrochemical performance of the supercapacitor. The carbon nanotube aerogel with its exceptional surface area and electrical conductivity, lays the foundation for lightning-fast charge transfer. Meanwhile, the metal-organic frameworks present at the interface, grant ions unbridled storage space contributing to efficient charge storage. The ulta-light-in-weight FCNT-MOF free-standing electrode exhibited an excellent specific capacitance of 465 F g−1 (116 mF cm−2) at 2 A g−1 with outstanding cyclic stability of 92 % after 6000 cycles. The flexible FCNT-MOF symmetric supercapacitor demonstrated a high energy density of 40.5 W h kg−1 at a power density of 1600 W kg−1. The simplified fabrication process, reduced active material requirements (0.25 mg cm−2), and enhanced performance make it an attractive option for supercapacitor application. Furthermore, the integration of this electrode design into supercapacitors holds great promise for portable electronics, electric vehicles, and renewable energy systems.

Simple construction of gadolinium cobaltite perovskite (GdCoO3): Unveiling the dynamic electrode potential for pseudocapacitors

BackgroundThe intermittent nature of renewable energy resources has led to an ongoing mismatch between energy demands and supply in modern societies. To address this issue, the design of well-defined nanostructures with unique physicochemical nature, has emerged as a promising solution. In this regard, perovskite (ABO3) nanostructured electrode materials have shown great potential in enhancing electrochemical performance. MethodsA simple co-precipitation technique was utilized to synthesize perovskite phase gadolinium-based binary metal oxide, i.e., GdCoO3. The obtained physiochemical characterization data revealed that the GdCoO3 electrode material possessed a high surface area that facilitates the diffusion of ions and enhances its specific capacitance. Significant findingsExtensive electrochemical characterization techniques were used (cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charging and discharging (GCD)) to analyze the electrochemical properties of the electrode material in this study. The charge storage mechanism of GdCoO3 was determined to be diffusion-controlled. When tested in an aqueous electrolyte (3 M KOH), GdCoO3 nano-electrode exhibited an excellent specific capacitance (519 F g–1) by a current density (1 A g–1). Furthermore, it demonstrates a significant capacitance retention rate (CRR) of 84.9 % subsequently 5000 cycles indicating its potential for long-term stability. The fabricated battery-type electrode holds promise in various applications including electric motors, flexible electronics, and energy storage devices.

Fabrication of Mn doped BiFeO3 as an electrode material for supercapacitor applications

Currently, supercapacitors (SCs) often recognized as electrochemical capacitor are category of energy storage devices that attained considerable attention from researchers. Perovskite materials exhibit significant potential in addressing global energy crisis concerns and act as effective electrode material for SCs application. The perovskite (bismuth ferrite) and manganese-doped (Mn-BiFeO3) nanocomposites were synthesized through the utilization of the hydrothermal method. This synthesis was conducted with the intention of exploring the potential performance of nanocomposites in the energy storage for the supercapacitor (SCs) application. In this work, scanning electron microscopy (SEM) was utilized to recognize the morphology of BiFeO3 nanoparticles incorporated in the transition metal (Mn). The EDX analysis confirmed the fabricated sample was pure and without any impurity. The investigation conducted on the Mn-BiFeO3 nanocomposites in the BET study has confirmed a notable surface area of around 49 m2 g−1. The investigation of energy storage applications involved the utilization of 2 M KOH electrolyte for conducting galvanic charge-discharge (GCD), cyclic voltammetry (CV) studies and electrochemical impedance spectroscopy (EIS). The nanocomposites consisting of BiFeO3-Mn have excellent specific capacitance (Cs) values of around 1795 F g−1 when tested at 1 A g−1, demonstrating best charge-discharge cyclic behavior; the computed values of both solution resistance Rs (1.08 Ω) and charge transfer resistance Rct (0.02 Ω) was calculated by the EIS graph. Our research findings demonstrate a method for synthesizing nanocomposites from the hydrothermal method that is efficient and scalable while also being cost-effective. These nanocomposites exhibit improved electrochemical performance, making them suitable for use for SCs applications and can used towards further energy storage devices.

Nanoarchitectonics of self-supporting porous carbon electrode with heteroatoms co-doped: For high-performance supercapacitors

Wood possesses a uniform hierarchical porous structure and high mechanical strength, rendering it an excellent precursor for the preparation of self-supporting carbon electrodes without binders and conductive agents. This paper presents an efficient method for synthesizing a self-supporting carbon electrode (HCW-0.7) with high specific surface area, hierarchical pore structure and abundant surface functional groups, utilizing simple hydrothermal pre-treatment and one-step thermochemical conversion process. The HCW-0.7 electrode demonstrates remarkable electrochemical performance, achieving an excellent specific capacitance of 298.52 F g−1 under a current density of 0.5 A g−1. The wood-based symmetrical supercapacitor (HSC) constructed with HCW-0.7 as the electrode has excellent energy density, power density and rate performance. At the power density of 287.5 W kg−1, HSC demonstrates an energy density of 9.43 Wh kg−1, exhibits its excellent electrochemical performance. Notably, even when subject to a higher power density of 5750 W kg−1, the energy density remains at 5.16 Wh kg−1. Furthermore, even after 20,000 charge and discharge cycles, HSC demonstrates a remarkable capacity retention rate of 96.24 %.

In-situ electronic modulation of ultra-high-capacity S-modified Cu/Cu2O electrodes for energy storage applications

Due to the modification of anions, an electron redistribution occurs at the metal ions can affect the electronic structure, and induce excellent specific capacity. Herein, we report an effective and low time-consuming method by in-situ wet chemical reduction at room temperature to construct S-modified Cu/Cu2O negative electrode material. Moreover, the sulfur can occupy partial O sites in Cu2O to play a crucial role in the electronic structure of the material, demonstrated by DFT calculation, XRD, XPS and XAS measurements. The prepared S-Cu/Cu2O samples exhibit excellent electrochemical performance with high specific capacity of 669 mAh·g−1 at 1 A·g−1, even 450 mAh·g−1 at 10 A·g−1. When the materials are composed as pseudo capacity-type cathode//battery-like anode (MnO2//S-Cu/Cu2O), and (+) battery-type//battery-type (-) (Ni-Cu hydroxide/Cu(OH)2/CF//S-Cu/Cu2O) hybrid capacitors, they show the energy density of 47.7 and 147.3 Wh·kg−1 at the power density of 636.2 and 800 kW·kg−1, respectively. Otherwise, the flexible MnO2//S-Cu/Cu2O hybrid capacitor is assembled, which also exhibits good performance at different bending conditions. This work can provide a simple method to prepare the electrode materials via in situ anion modification for high-energy density battery-like energy storage systems.

Modulating metal-free Zn-bromine batteries with covalent organic framework anode

Recently, deploying a reversible Zn2+-host anode to fabricate metal-free aqueous Zn ion batteries (AZIBs) provides an effective solution to solve the hindrances of Zn metal anode. However, the unsatisfactory energy density (<100 Wh kg−1) of assembled metal-free AZIBs is limited by low operated voltage of device (0.8∼1 V) and insufficient capacity of anode (<150 mAh g−1). Herein, for the first time, we proposed a polyimide covalent organic framework (Tp-DANT-COF) with multiple redox centers (C=O) as metal-free anode. It is found that the highly order interlayer structure, robust covalent framework and extended π-conjugated domain play key roles to facilitate ion/electron transport, structural integrity and active centers accessibility. As results, the COF anode exhibits an excellent specific capacity of 235.7 mAh g−1 at 0.1 A g−1, superior rate performance of 179.1 mAh g−1 even at 10 A g−1 and cycling stability over 10,000 cycles. Besides, the dual cation charge storage mechanism and favorable co-accommodate configuration of Zn2+/H+ are revealed by various characterizations and theory calculation. Importantly, matched to bromine cathode (AC-KBr) with high redox potential, the fabricated Tp-DANT-COF//AC-KBr full device achieves high energy density of 110.9 Wh kg−1 with 1.2 V operating voltage, exceeding the most reported congenerical devices.

P2/O3 Biphasic Cathode Material through Magnesium Substitution for Sodium-Ion Batteries.

P2-type Fe-Mn-based oxides offer excellent discharge specific capacity and are as affordable as typical layered oxide cathode materials for sodium-ion batteries (SIBs). After Cu modification, though they can improve the cycling performance and air stability, the discharge specific capacity will be reduced. Considering the complementary nature of biphasic phases in electrochemistry, hybridizing P2/O3 hybrid phases can enhance both the storage performance of the battery and specific capacity. Herein, a hybrid phase composite with high capacity and good cycle performance is deliberately designed and successfully prepared by controlling the amount of Mg doping in the layered oxide. It has been found that the introduction of Mg can activate anion redox in the oxide layer, resulting in a significant increase in the specific discharge capacity of the material. Meanwhile, the dual-phase structure can produce an interlocking effect, thus effectively alleviating structure strain. The degradation of cycling performance caused by structural damage during the high-voltage charging and discharging process is clearly mitigated. The results show that the specific discharge capacity of Na0.67Cu0.2Mg0.1Fe0.2Mn0.5O2 is as high as 212.0 mAh g-1 at 0.1C rate and 186.2 mAh g-1 at 0.2C rate. After 80 cycles, the capacity can still maintain 88.1%. Moreover, the capacity and cycle performance as well as the stability can still remain stable even in the high-voltage window. Therefore, this work offers an insightful exploration for the development of composite cathode materials for SIBs.

Polybenzidine-MnO2 nanocomposite on anodized graphite sheet as a novel system for high-performance supercapacitors

In this work, we report for the first time the in-situ synthesis of polybenzidine‑manganese oxide (PB-MnO2) nanocomposite on anodized graphite sheet (AGS). The PB-MnO2/AGS electrode is easily fabricated through the electrochemical anodization of the graphite sheet followed by the polymerization of the benzidine monomer using KMnO4 as an oxidant and MnO2 source. The results of various instrumental analysis confirm that the PB-MnO2 nanocomposite is successfully formed on the AGS without any binder. Cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques strongly prove the pseudocapacitive nature of the electrode. The PB-MnO2/AGS electrode shows a high capacitance of 950 mF cm−2 at 0.5 mA cm−2 in 1.0 M H2SO4 solution with a maximum power and energy density of 64.65 mWh cm−2 and 1.75 W cm−2. Solid-state symmetrical supercapacitor device fabricated with PB-MnO2/AGS electrode shows that this device has an excellent specific capacity of about 190.27 mF cm−2 at 0.5 mA cm−2 and maximum power and energy density of 12.375 W cm−2 and 85.625 mWh cm−2. The cyclic life of 87.22 % after 5000 GCD cycles without any ohmic drop indicates that the PB-MnO2/AGS electrode can be a promising candidate for the fabrication of high-performance supercapacitor devices in the future.

Metal-heteroatom-doped CoS/MXene nanohybrid for efficient supercapacitor electrode materials

Developing electrode active materials with abundant active sites, hierarchical porous structure, and good chemical/structure stability significantly promote energy density and cycling stability. However, it is not easy to realize all features for a single component, various strategies such as hetero-atom doping, hybridizing route, and defect engineering could provide possible approaches. Herein, FeCoS were hybridized with MXene to achieve high stability and superior electrochemical performance electrode materials, the well-designed heterogeneous nanohybrids have several merits for abundant active sites, exceptional structural durability, excellent electrical conductivity own to the strong interfacial connection and favorable synergistic effect between the two phases. Consequently, the optimal hybrid electrode demonstrated superior electrochemical performance with an excellent specific capacity of 1190 C g−1 at a current density of 2 A g−1 and outstanding rate capability for 900 C g−1 at 10 A g−1. Moreover, the metal-doped with various cations of Fe2+, Al2+, Ni2+ and Sn2+ were separately introduced into the structural phase to evaluate the feasibility, and the strategy not only provides the feasible and universal development of the stable interface between the hybrids, but also paved the way for the design of high-capacity electrodes.

Electrochemical energy storage application of MOF-derived porous NiO thin films synthesized by solvothermal route

Metal oxides are the most suitable materials for supercapacitors because of their strong electrical characteristics and cheap prices. Owing to its large surface area, controlled pore structure, uniformity, the metal-organic frameworks are employed as inventive material for electrodes in the field of energy storage. In this report, Ni-MOFs have been prepared on conducting stainless steel substrates using a solvothermal technique with different Ni concentrations. Further, these films were annealed at 350 °C for getting NiO phase. The crystalline nature of MOF-derived NiO is confirmed by XRD. The surface morphology of the films has been studied with FE-SEM, showing a nanosheet-like structure. Consequently, electrochemical tests on NiO electrodes were performed in 1 M KOH with a potential window of -0.2–0.5 V. The NiO electrode deposited with 0.3 M concentration delivers a specific capacity of 680 C g−1 at a current density of 0.5 mA cm−2, an energy density of 22.40 Wh kg−1 at a power density of 2.4 kW kg−1 and good cyclic performance with 96% retention after 5000 cycles. The synthesized MOF derived NiO showed excellent specific capacity and good cycle stability due to their large surface area, porous and more durable structure. Hence, the synthesis approach designated here may provide an efficient way to develop MOF-derived NiO for effective supercapacitor applications.

Synergistic modulation of alkaline aluminum-air battery based on localized water-in-salt electrolyte towards anodic self-corrosion

A long-term hurdle for Al-air batteries is the severe open-circuit corrosion, irreversibly self-discharging more than 80% per month depending on the battery design. In this work, we introduce an ionic liquid-ethylene glycol system as a local water-in-salt electrolyte to modify the conventional aqueous solution. At the same time, synergistic effect between morin and ionic liquid is employed to further reduce the salt component, as well as improving the performance. Experiments such as electrochemical test, surface analysis and theoretical calculations prove that the additives can modulate the anodic interface and restrain the free water molecules through hydrogen bond. Thus, Al-6061 anode suffers low parasitic corrosion rate and gains stable surface. Furthermore, the performance of assembled aluminum air battery is greatly improved with an excellent specific capacity of 2010 mAh/g, reliable cycle stability and anode utilization.

Copper–Iron Selenides Nanoflakes and Carbon Nanotubes Composites as an Advanced Anode Material for High‐Performance Lithium‐Ion Batteries

Metal selenides are widely considered as an emerging anode electrode material for lithium‐ion batteries (LIBs). Hence, the present study uses a conductive carbon materials matrix such as carbon nanotubes (CNTs) with copper–iron selenide (CuFeSe2). The composites (CuFeSe2@CNTs) are synthesized by a hydrothermal method and examined for electrochemical performance as anode applications in LIBs. Herein, the CuFeSe2@CNTs show excellent specific capacity of 783.7 and 720.6 mA h g−1 at 0.1 and 1 A g−1, respectively. This composite further exhibits a high‐capacity value compared to only FeSe2 and CuFeSe2 and a reversible capacity of 691 mA h g−1 after 200 cycles at 1 A g−1 current density. Moreover, the homogeneous combination of CuFeSe2 nanoflakes and CNTs provides structural stability that reduces the volume change during lithium‐ion interactions and successively improves the conductivity of the complex, which is advantageous for better ion and electron kinetics during the reaction.

Advances in Aqueous Zinc Ion Batteries based on Conversion Mechanism: Challenges, Strategies, and Prospects.

Recently, aqueous zinc-ion batteries with conversion mechanisms have received wide attention in energy storage systems on account of excellent specific capacity, high power density, and energy density. Unfortunately, some characteristics of cathode material, zinc anode, and electrolyte still limit the development of aqueous zinc-ion batteries possessing conversion mechanism. Consequently, this paper provides a detailed summary of the development for numerous aqueous zinc-based batteries: zinc-sulfur (Zn-S) batteries, zinc-selenium (Zn-Se) batteries, zinc-tellurium (Zn-Te) batteries, zinc-iodine (Zn-I2) batteries, and zinc-bromine (Zn-Br2) batteries. Meanwhile, the reaction conversion mechanism of zinc-based batteries with conversion mechanism and the research progress in the investigation of composite cathode, zinc anode materials, and selection of electrolytes are systematically introduced. Finally, this review comprehensively describes the prospects and outlook of aqueous zinc-ion batteries with conversion mechanism, aiming to promote the rapid development of aqueous zinc-based batteries.

Hierarchical high K content birnessite MnO2 nanosheet arrays as high capacity cathode for asymmetric supercapacitor with broaden potential window of 2.6 V

High specific capacitance and energy density for energy storage devices are dependent on the types of electrodes selection and operational working potential windows. Birnessite MnO2 is reported as the astounding material to show strong electrochemical performances due to it's widen inter-planar spacing, capable to accommodate the alkaline ions for the better outcomes. Herein this article, high K content Birnessite MnO2 nanosheet arrays at carbon cloth substrate (K0.46MnO2 NSAs@CC) are successfully fabricated to optimize its structural, morphological and electrochemical performances as cathode for supercapacitors (SCs). K0.46MnO2 NSAs@CC is operated at broaden potential window from 0 to 1.3 V to achieve excellent specific capacitance of ∼375 F g−1. Reported broaden potential window provides the opportunity for the construction of aqueous asymmetric supercapacitors (ASC) to operate above 2.0 V. For the construction of efficient ASC, Bi2S3 nanoflakes interconnected nanosheets at carbon cloth (Bi2S3 NFNS@CC) are synthesized as anode capable to operate at negative (−1.3 to 0 V) potential window. The 2.6 V ASC is constructed by K0.46MnO2 NSAs@CC as cathode and Bi2S3 NFNS@CC as an anode (K0.46MnO2 NSAs@CC//Bi2S3 NFNS@CC). K0.46MnO2 NSAs@CC//Bi2S3 NFNS@CC as ASC is presenting excellent energy density of ∼72 Wh kg−1 on top of outstanding cycle performance and rate capability compatible with the earlier reported MnO2-based ASCs. This work is elaborating the new guidelines for novel electrode materials scheme and possibilities to achieve broaden potential windows capable to be utilized in practical devices.

Rational design of crystalline/amorphous nickel manganese phosphate octahydrate heterostructure for high-performance aqueous and all-solid-state asymmetric supercapacitors

Designing a rational architecture and combining diverse metal cations are of vital importance to obtain high-performance bimetallic compounds for energy storage purposes. Herein, a novel crystalline/amorphous nickel manganese phosphate octahydrate heterostructure grown in-situ on nickel foam was synthesized by a facile hydrothermal method followed by annealing in argon. The composite exhibits exceptional performance by adjusting the atomic ratio of redox metals (nickel and manganese) with multiple oxidation states. Specifically, the composite shows an excellent specific capacitance of 2351.6 F g−1 at a current density of 1 A g−1 and 67.3 % capacity retention after 3000 cycles at 10 A g−1. This remarkable performance can be attributed to the unique heterogeneous structure of the composite and the synergistic effect between two metals, improving the electronic conductivity. Density functional theory (DFT) calculations further confirm the reduction of band gap and conductivity enhancement. Furthermore, the crystalline portions offer not only active sites but also good mechanical support, while the amorphous components effectively promote ion diffusion and reaction. An aqueous asymmetric supercapacitor was assembled employing nickel manganese phosphate octahydrate as cathode and active carbon as anode, displaying a high energy density of 66.22 Wh kg−1 at a power density of 400 W kg−1 and outstanding cycling performance at 60 mA cm−2 (81.03 % capacitance retention after 15,000 cycles). Additionally, the fabricated all-solid-state asymmetric supercapacitor also displays a remarkable electrochemical performance.

Isostructural dual-ligand-based MOFs with different metal centers in response to diverse capacity lithium-ion battery anode

Metal-organic frameworks (MOFs) have become one of the most promising active materials in lithium-ion batteries (LIBs) due to their designable molecular architecture and tunable functionality. Herein, we report a series of isostructural three-dimensional MOFs of divalent Mn (1), Co (2), and Zn (3), [MII2(H2O)2(4,4′-bipy)(mal)2]n as anode materials for LIBs. The MOFs can be prepared within a few minutes using a facile microwave-heating technique. Investigations on electrochemical properties and performance as active materials for LIBs anodes showed that Co-MOF 2 has higher efficiency than the Mn and Zn congeners, with an excellent specific capacity of 732 mA h g−1 after 200 cycles, which is distinguished electrochemical performance in specific capacity and rate cycle performance over the previous MOF-based materials. First-principles computations revealed the importance of the metal center of MOFs on the Li-ion batteries performance since it is involved in the Li diffusion mechanism.

Unleashing the power: Superior properties of fluorographene-derived materials for energy storage applications

Fluorographene exhibits a rich chemistry and a wide range of applications in energy storage devices. This review, which is based on our lab results acquired in the last decade, explores the synthesis, properties, and performance of fluorographene-based materials in supercapacitors and batteries. Fluorographene can be prepared through mechanical or chemical delamination of graphite fluoride, allowing for scalable synthesis and further chemical processing. The chemical versatility of fluorographene enables a wide portfolio of chemical reactions, leading to a new class of graphene derivatives. Graphene acid, a product of fluorographene chemistry, exhibits excellent specific capacitance, cycling stability, and rate capability. Hybridizing graphene acid with metal-organic frameworks can achieve even higher energy and power densities. Furthermore, nitrogen-doped graphene derived from fluorographene demonstrates remarkable capacitive behavior, making it an efficient electrode material for supercapacitors. Additionally, fluorographene-based materials, such as graphene acid, graphene-sulfur hybrids, and graphene-based anodes, have exhibited outstanding performance in lithium-ion and lithium-sulfur batteries. The scalable synthesis, high performance, and versatility of fluorographene-derived materials render them attractive for practical energy storage applications. The unique properties and wide range of chemistries offered by fluorographene chemistry open new possibilities for improving advanced energy storage devices.