Electrode Materials Research Articles

Elevating Platinum to Volumetric Capacitance: High Surface Area Electrodes through Reactive Pt Sputtering.

Platinum is the most widespread electrode material used for implantable biomedical and neuroelectronic devices, motivating exploring ways to improve its performance and understand its fundamental properties. Using reactive magnetron sputtering, PtOx is prepared, which upon partial reduction yields a porous thin-film form of platinum with favorable properties, notably record-low impedance values outcompeting other reports for platinum-based electrodes. It is established that its high electrochemical capacitance scales with thickness, in the way of volumetric capacitor materials like IrOx and poly(3,4-ethylenedioxythiophene), PEDOT. Unlike these two well-known analogs, however, it is found that PtOx capacitance is not caused by reversible pseudofaradaic reactions but rather due to high surface area. In contrast to IrOx, PtOx is not a reversible valence-change oxide, but rather a porous form of platinum. The findings show that this oxygen-containing form of Pt can place Pt electrodes on a level competitive with IrOx and PEDOT. Due to its relatively low cost and ease of preparation, PtOx can be a good choice for microfabricated bioelectronic devices.

High Safety Electrolyte Design for Enabling High Energy-Density System of LiNi0.8Co0.1Mn0.1O2//Phosphorus by Simultaneously Adjusting Dual Electrode/Electrolyte Interfaces.

The demand for state-of-the-art high-energy-density lithium-ion batteries is increasing. However, the low specific capacity of electrode materials in conventional full-cell systems cannot meet the requirements. Ni-rich layered oxide cathodes such as Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) have a high theoretical specific capacity of 200 mAh g-1, but it is always accompanied by side reactions on the electrode/electrolyte interface. Phosphorus anode possesses a high theoretical specific capacity of 2596 mAh g-1, but it has a huge volume expansion (≈300%). Herein, a highly compatible and secure electrolyte is reported via introducing an additive with a narrow electrochemical window, Lithium difluoro(oxalato)borate (LiDFOB), into 1m LiPF6 EC/DMC with tris (2,2,2-trifluoroethyl) phosphate (TFEP) as a cosolvent. LiDFOB participates in the formation of organic/inorganic hybrid electrode/electrolyte interface layers at both the cathode and anode sides. The side reactions on the surface of the NCM811 cathode and the volume expansion of the phosphorus anode are effectively alleviated. The NCM811//RP full cell in this electrolyte shows high capacity retention of 82% after 150 cycles at a 0.5C rate. Meanwhile, the electrolyte shows non-flammability. This work highlights the importance of manipulating the electrode/electrolyte interface layers for the design of lithium-ion batteries with high energy density.

Theoretical investigation of NbB as an electrode material for Li/Na-ion batteries

The utilization of MBenes as electrode materials for lithium/sodium-ion batteries (LIBs/NIBs) has emerged as a prominent research area. The potential application of two-dimensional niobium boride (NbB) in LIBs/NIBs was explored through first-principles calculations. The results indicate that the monolayer of NbB exhibits exceptional dynamic stability, thermodynamic stability and electrical conductivity. The migration path of Li/Na on the NbB surface was determined, revealing diffusion barriers as low as 0.034 and 0.017 eV respectively, indicating the exceptional mobility and reversibility exhibited by NbB. The theoretical capacities of Li and Na on NbB are 258 and 323 mAh g−1, respectively. The open circuit voltage (OCV) varies within the range of 0.58 to 0.71 V and 0.05 to 0.81 V for Li/Na concentrations. Meanwhile, the investigation into the influence of various functional groups of NbB on the adsorption properties of Li/Na atoms reveals that both NbBO and NbBS surfaces retain their maximum capacity for Li/Na adsorption, whereas the NbBSe surface fails to achieve complete layer adsorption of Li/Na atoms. The introduction of the S functional groups not only maintains the ultra-low diffusion barrier (0.09 eV) of Na ions but also results in a significant decrease in the average OCV of Li/Na adsorption, which is approximately 0.37 and 0.14 V, respectively. The electrochemical properties of NbB in LIBs/NIBs are exceptional, positioning it as a promising electrode material within the MBenes family.

Advancing Frontiers: A High-Impact Study on the Synthesis, Characterization, and Superior Device Performance of AlCr2O4/MXene Nanocomposites

Abstract Here we present the fabrication of a multilayer resistive memory device (ReRAM) utilizing AlCr2O4/MXene nanocomposite. Comprehensive investigations into the structural and morphological properties of the nanostructures were conducted using various characterization techniques. The fabricated device was tested by measuring I-V characteristics at different current applications which encompasses all previous results. The band gap value for the nanocomposite was reduced to 2.42 eV while that for AlCr2O4 was measured at 3.25 eV via photoluminescence spectrum. Average particle size of the AlCr2O4/MXene nanocomposite was determined to be 25 nm through powder X-ray diffraction analysis. Crystallographic analysis revealed that all crystal peaks conform to the R-3c (167) space group, indicative of a standard hexagonal crystal structure. Energy-dispersive X-ray readings provided further confirmation that all required elements are present in the sample, affirming successful synthesis of the nanocomposite. Notably, the nanocomposite demonstrated exceptional performance as an electrode material in ReRAM, as evidenced by its current-voltage characteristics, making the AlCr2O4/MXene nanocomposite suitable for a wide range of next-generation device applications.

A comprehensive review on developments and future perspectives of biopolymer‐based materials for energy storage

AbstractDriven by the escalating environmental impact of synthetic materials, there has been a growing focus on employing eco‐sustainable biomass‐derived biopolymers and native materials as a viable alternative to traditional energy storage applications. Biopolymer‐based energy devices, like batteries, supercapacitors, electrode materials, and ion‐exchange membranes, a novel and eco‐conscious approach, hold great potential for flexible and smart electrochemical energy storage and conversion devices, owing to their affordability, environmental sustainability, and biodegradability. This critical review outlines the sources and properties of biopolymers leading to energy storage and emphasizes their utilization in the energy sector. Despite their inherent constraints, biopolymers can be effectively leveraged when combined with other materials in composites. This collaborative approach not only refines their intrinsic physical attributes but also elevates the electrochemical performance of biologically active molecules. In this regard, bionanocomposites, a class of materials combining biopolymers and nanoparticles, have emerged as a promising greener alternative to conventional petroleum‐based polymers. Their biocompatibility, biodegradability, and antimicrobial properties have promoted their increased commercialization, thus paving the way for a more sustainable future. The review concludes by identifying and effectively addressing the limitations, challenges, and future perspectives of biopolymers in energy storage applications.

Towards Circular Energy: Exploring Direct Regeneration For Lithium-Ion Battery Sustainability.

Lithium-ion batteries (LIBs) are rapidly developing into attractive energy storage technologies. As LIBs gradually enter retirement, their sustainability is starting to come into focus. The utilization of recycled spent LIBs as raw materials for battery manufacturing is imperative for resource and environmental sustainability. The sustainability of spent LIBs depends on the recycling process, whereby the cycling of battery materials must be maximized while minimizing waste emissions and energy consumption. Although LIB recycling technologies (hydrometallurgy and pyrometallurgy) have been commercialized on a large scale, they have unavoidable limitations. They are incompatible with circular economy principles because they require toxic chemicals, emit hazardous substances, and consume large amounts of energy. The direct regeneration of degraded electrode materials from spent LIBs is a viable alternative to traditional recycling technologies and is a nondestructive repair technology. Furthermore, direct regeneration offers advantages such as maximization of the value of recycled electrode materials, use of sustainable, non-toxic reagents, high potential profitability, and significant application potential. Therefore, this review aims to investigate the state-of-the-art direct LIB regeneration technologies that can be extended to large-scale applications. This article is protected by copyright. All rights reserved.

Investigation of cathode properties of two-dimensional NbS2Cl2 for Li and Na-ion batteries using density functional theory

Exploring novel two-dimensional materials (2D) for electrode and electrochemical storage applications stands as a pivotal pursuit in advancing renewable energy technologies. While recent research has predominantly focused on anode materials, cathode materials have received comparatively lesser attention. This study delves into the potential cathode applications of the novel two-dimensional material NbS2Cl2 using density functional theory. Fundamental properties, encompassing electronic and thermodynamic attributes, were scrutinized to comprehend the material’s characteristics. Our investigation extended to examining the adsorption and diffusion properties of these electrode materials. Comprehensive calculations of mechanical and thermodynamic properties reaffirmed the stability of this system. Upon adsorption of Li/Na atoms, the conducting nature emerged, evident through charge density difference and projected density of states. Our findings notably reveal minimal diffusion barriers of 1.5 eV and 0.35 eV for Li and Na atoms. Moreover, the observed open circuit voltages for adsorbed Li and Na ions were 4.69 V and 2.62 V, respectively. The calculated theoretical capacity for adsorbed Li-ion on 2D-NbS2Cl2 is 400 mAh g−1, while for Na-ion adsorption, it is 353 mAh g−1, awaiting validation through future experimental verifications.

Constructing and Evaluating Machine-Learned Interatomic Potentials for Li-Based Disordered Rocksalts.

Lithium-based disordered rocksalts (LDRs), which are an important class of positive electrode materials that can increase the energy density of current Li-ion batteries, represent a significantly complex chemical and configurational space for conventional density functional theory (DFT)-based high-throughput screening approaches. Notably, atom-centered machine-learned interatomic potentials (MLIPs) are a promising pathway to accurately model the potential energy surface of highly disordered chemical spaces, such as LDRs, where the performance of such MLIPs has not been rigorously explored yet. Here, we represent a comprehensive evaluation of the accuracy, transferability, and ease of training of five atom-centered MLIPs, including the artificial neural network potentials developed by the atomic energy network (AENET), the Gaussian approximation potential (GAP), the spectral neighbor analysis potential (SNAP) and its quadratic extension (qSNAP), and the moment tensor potential (MTP), in modeling a 11-component LDR chemical space. Specifically, we generate a DFT-calculated data set of 10,842 configurations of disordered LiTMO2 and TMO2 compositions, where TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and/or Cu. To provide a point-of-comparison on the performance of atom-centered MLIPs, we also trained the neural equivariant interatomic potential (NequIP) on a subset of our data. Importantly, we find AENET to be the best potential in terms of accuracy and transferability for energy predictions, while MTP is the best for atomic forces. While AENET is the fastest to train among the MLIPs considered at low number of epochs (300), the training time increases significantly as epochs increase (3300), with a corresponding reduction in training errors (∼60%). Note that AENET and GAP tend to overfit in small data sets, with the extent of overfitting reducing with larger data sets. Finally, we observe AENET to provide reasonable predictions of average Li-intercalation voltages in layered, single-TM LiTMO2 frameworks, compared to DFT (∼10% error on average). Our study should pave the way both for discovering novel disordered rocksalt electrodes and for modeling other configurationally complex systems, such as high-entropy ceramics and alloys.

Electrochemical deposition of NiO/NiCo2O4 nanostructures for high-performance supercapacitors

NiO is widely used in supercapacitors because of its low toxicity, low price and environmental friendliness. In this study, NiO/NiCo2O4 composites were prepared on nickel foam substrates using a simple electrochemical deposition technique. By adjusting the deposition time in the electrochemical parameters, the optimum conditions for the deposition process can be fine-tuned. Characterization techniques such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) confirmed the synthesis of NiO/NiCo2O4 composites. The electrochemical properties of the composite electrode NiO/NiCo2O4/NF were evaluated by cyclic voltammetry (CV), electrostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The specific capacitance (Cs) of the prepared composite electrode NiO/NiCo2O4/NF electrode was 717.8 mF/cm2 at 2 mA/cm2 with a capacitance retention of 74.8 %. In addition, Aqueous symmetric supercapacitors (SSCs) and all-solid symmetric supercapacitors were assembled based on the composite NiO/NiCo2O4/NF electrode, respectively. The aqueous SSCs have a power density of 880 μW/cm2 and an energy density of 123.0 μWh/cm2, the all-solid symmetric supercapacitors have a power density of 960 μW/cm2 and an energy density of 24.27 μWh/cm2. The series connection of two identical capacitors can light up light-emitting diodes (LEDs). This research presents a promising technique for producing Ni-based electrode material for supercapacitors.

Experimental and theoretical studies on cobalt ruthenium phosphate structure optimization towards supercapacitor application

Recent studies have given indications that nanoarchitectured binary transition metal phosphates can act as potential supercapacitor (SC) electrode materials due to their exceptional energy storage capacity and remarkable electrochemical stability. However, the highly amorphous nature or broad X-ray diffraction peaks of metal phosphates put a limit on the structural optimization of these materials. We demonstrate a combined experimental and theoretical study leading to an optimized cobalt-ruthenium phosphate (CRP) structure for high-performance SC application. The material structure was optimized by detailed density functional theory (DFT) calculations, including the Bader charge analysis, DOS, and PDOS, revealed the lattice and volume expansion, reduced band gap, and improved conductivity of the cobalt phosphate lattice by including ruthenium in the cobalt phosphate. These predictions are verified with experimental band gap and high-resolution transmission electron microscope plane image indexing. Further, the CRP was developed by potentiostatic deposition onto the carbon cloth substrate. The flexible CRP electrode exhibited a high specific capacitance of 1258 F g−1 (943.5C g−1) in the aqueous 2 M KOH electrolyte. The asymmetric SC device (CRP//activated carbon) has exhibited an excellent specific energy of ∼59 Wh kg−1 at a specific power of ∼751 W kg−1.

Phytic acid as an eco-friendly phosphorus source in the synthesis of phosphorus-doped NiCo2O4 for supercapacitor electrodes

This study explores the synthesis of nickel-cobalt bimetallic precursors using phytic acid (PA) as a phosphorus source and their application as supercapacitor electrodes. Through high-temperature annealing, these precursors were converted into phosphorus-doped nickel-cobalt bimetallic oxides (NCO) with certain defects. The morphologies and particle size of NCO can be easily adjusted by the amount of PA. Compared to the undoped nickel-cobalt bimetallic oxides, the phosphorus-doped materials exhibited significantly enhanced electrochemical activity and specific capacitance. The optimized electrode exhibits the highest specific capacitance of 1075 F·g−1 at a current density of 1 A·g−1. The asymmetric supercapacitor assembled together with activated carbon can deliver a relatively high energy density of 39.8 Wh·kg−1 at a power density of 696 W·kg−1. Additionally, this paper provides a detailed discussion on the impact of phosphorus doping on the performance of supercapacitor electrodes and the potential of PA as an eco-friendly phosphorus source in the synthesis of high-performance electrode materials.

Lithium-Ion Dynamic and Storage of Atomically Precise Halogenated Nanographene Assemblies via Bottom-Up Chemical Synthesis.

Graphene has received much scientific attention as an electrode material for lithium-ion batteries because of its extraordinary physical and electrical properties. However, the lack of structural control and restacking issues have hindered its application as carbon-based anode materials for next generation lithium-ion batteries. To improve its performance, several modification approaches such as edge-functionalization and electron-donating/withdrawing substitution have been considered as promising strategies. In addition, group 7A elements have been recognized as critical elements due to their electronegativity and electron-withdrawing character, which are able to further improve the electronic and structural properties of materials. Herein, we elucidated the chemistry of nanographenes with edge-substituted group 7A elements as lithium-ion battery anodes. The halogenated nanographenes were synthesized via bottom-up organic synthesis to ensure the structural control. Our study reveals that the presence of halogens on the edge of nanographenes not only tunes the structural and electronic properties but also impacts the material stability, reactivity, and Li+ storage capability. Further systematic spectroscopic studies indicate that the charge polarization caused by halogen atoms could regulate the Li+ transport, charge transfer energy, and charge storage behavior in nanographenes. Overall, this study provides a new molecular design for nanographene anodes aiming for next-generation lithium-ion batteries.

Structural and Electronic Factors behind the Electrochemical Stability of 3D-Metal Tungstates under Oxygen Evolution Reaction Conditions.

Transition metal tungstates (TMTs) possess a wolframite-like lattice structure and preferably form via an electrostatic interaction between a divalent transition metal cation (MII) and an oxyanion of tungsten ([WO4]2-). A unit cell of a TMT is primarily composed of two repeating units, [MO6]oh and [WO6]oh, which are held together via several M-μ2-O-W bridging links. The bond character (ionic or covalent) of this bridging unit determines the stability of the lattice and influences the electronic structure of the bulk TMT materials. Recently, TMTs have been successfully employed as an electrode material for various applications, including electrochemical water splitting. Despite the wide electrocatalytic applications of TMTs, the study of the structure-activity correlation and electronic factors responsible for in situ structural evolution to electroactive species during electrochemical reactions is still in its infancy. Herein, a series of TMTs, MIIWVIO4 (M = Mn/Fe/Co/Ni), have been prepared and employed as electrocatalysts to study the oxygen evolution reaction (OER) under alkaline conditions and to scrutinize the role of transition metals in controlling the energetics of the formation of electroactive species. Since the [WO6]oh unit is common in the TMTs considered, the variation of the central atom of the corresponding [MO6]oh unit plays an intriguing role in controlling the electronic structure and stability of the lattice under anodic potential. Under the OER conditions, a potential-dependent structural transformation of MWO4 is noticed, where MnWO4 appears to be the most labile, whereas NiWO4 is stable up to a high anodic potential of ∼1.68 V (vs RHE). Potential-dependent hydrolytic [WO4]2- dissolution to form MOx active species, traced by in situ Raman and various spectro-/microscopic analyses, can directly be related to the electronic factors of the lattice, viz., crystal field splitting energy (CFSE) of MII in [MO6]oh, formation enthalpy (ΔHf), decomposition enthalpy (ΔHd), and Madelung factor associated with the MWO4 ionic lattice. Additionally, the magnitude of the Löwdin and Bader charges on M of the M-μ2-O-W bond is directly related to the degree of ionicity or covalency in the MWO4 lattice, which indirectly influences the electronic structure and activity. The experimental results substantiated by the computational study explain the electrochemical activity of the TMTs with the help of various structural and electronic factors and bonding interactions in the lattice, which has never been realized. Therefore, the study presented here can be taken as a general guideline to correlate the reactivity to the structure of the inorganic materials.

Exploring the mechanism of removing Cd from polluted soil using electrochemical leaching with straw carbon film electrode

The study presents a novel approach to remediating heavy metal-contaminated soil using electrochemical technology and chemical leaching. The researchers developed a new electrode material from waste straw and an environmentally friendly leaching agent using straw fermentation liquid. Combining electrochemical technology with chemical leaching provides a powerful remediation solution for heavy metal-contaminated soil, demonstrating efficiency and thoroughness. However, challenges include developing recyclable electrode materials and environmentally friendly leaching agents. This study addresses these challenges by pioneering a biochar-based electrode material and an eco-friendly leaching agent. Waste straw undergoes pyrolysis at 1000 °C to produce a conductive biochar, which is then combined with ethyl cellulose to form a film, creating biochar electrode materials. The developed straw fermentation solution, an environmentally friendly leaching agent, is used for Cd-contaminated soil remediation through combined electrochemical-chemical leaching. Results show soil Cd removal efficiency peaking at 59.5% with a singular chemical leaching agent. The combined method increases the Cd removal rate to a maximum of 91%. Furthermore, the study elucidate the potential mechanism of cadmium removal through techniques such as XRD, SEM, and infrared spectroscopy. To evaluate the efficacy of our approach, the study conducted Chinese cabbage pot-cultivation experiments. Remarkably, the physicochemical properties of soil remained largely unchanged after the reaction, while Chinese cabbage growth in treated soil surpassed that of the control group. This study not only removes Cd from the soil, reducing secondary pollution, but also establishes electrode recyclability, offering a prospective solution for large-scale soil heavy metal pollution remediation.

Highly Tribo-Positive Nylon-11 Film Fabricated by Multiscale Structural Regulation through a Roll-to-Roll Processing.

Triboelectric polymers have attracted extensive attention due to their great electron-accepting and electron-donating properties in contact electrification as well as their flexible and low-cost merits and have become promising electrode materials in triboelectric nanogenerators (TENGs). However, most research has exclusively focused on improving the electron capture capability of the triboelectric layer, neglecting to enhance the electron-donating capability, which leads to a low output performance of TENG and limits its practical application. In this study, we developed a method to fabricate highly tribo-positive Nylon-11 film through roll-to-roll processing. Paired with the poly(tetrafluoroethylene) triboelectric layer, the transferred charge density of contact-separation TENG based on Nylon-11 film prepared by this method reaches 291.1 μC/m2, which has been improved by 12.4% compared with the conventional compression molding sample. The novel fabricating method can regulate the surface functional groups to achieve higher surface potential and obtain a favorable pseudohexagonal crystal phase, leading to an increasing transferred charge density in triboelectrification. Additionally, it has been analyzed that higher chemical potential of materials can facilitate the transfer of electrons from the triboelectric polymer surface. This study provides a nonadditive, simple, and effective strategy to fabricate excellent tribo-positive material, which can significantly enhance the performance of TENG.

Supercapacitor Performance of Sulfonyldibenzene Derivative-Functionalized Graphene Aerogel.

3D aerogels incorporating functionalized reduced graphene oxide (SUL/rGO) were prepared as a hydrothermal method utilizing graphene oxide (GO) and a sulfonyldibenzene derivative (SUL) as raw materials. The aromatic compound SUL, which contains hydroxyl and sulfonyl groups, was bonded to reduced graphene oxide (rGO) through π-π connections. The obtained composite material exhibited porosity within its structure with improved hydrophilicity, along with excellent electrochemical characteristics. This improvement was ascribed to the specific rGO structure, as well as the pseudocapacitance inherent in SUL, both of which synergistically contribute to improvement in the characteristics of the prepared electrode materials. Also, an analysis was performed employing density functional theory from which the density of states and adsorption energy of SUL on the surface of rGO were computed to further investigate the charge storage process within the prepared composite. The prepared SUL/rGO-2 electrode exhibited the highest specific capacitance value of 388 F/g at a current density equal to 1 A/g. The constructed symmetrical supercapacitor, SUL/rGO-2//SUL/rGO-2, attained an energy density value of 14.55 Wh/kg at a power density equal to 350 W/kg with an exceptional galvanostatic charge-discharge (GCD) cyclic stability equal to 91% following 10 000 cycles. Therefore, this review presents a novel functionalized graphene-based material incorporating hydroxyl and sulfonyl groups, which holds promise in future energy storage applications.

Integrated Design for Discrete Sulfur@Polymer Nanoreactor with Tandem Connection as Lithium-Sulfur Battery Cathodes.

Apart from electrode material modification, architecture design and optimization are important approaches for improving lithium-sulfur battery performance. Herein, an integrated structure with tandem connection is constructed by confining nanosulfur (NS) in conductive poly(3,4-ethylenedioxythiophene) (PEDOT) reaction chambers, forming an interface of discrete independent nanoreactor units bonded onto carbon nanotubes (noted as CNT/NS@PEDOT). The unique spatial confinement and concentration gradients of sulfur@PEDOT nanoreactors (SP-NRs) can promote reaction kinetics while facilitating rapid polysulfide transformation and minimizing dissolution and diffusion losses. Meanwhile, overall ultrahigh energy input and output are achieved through tandem connection with carbon nanotubes, isolation with PEDOT coating, and synergistic multiplicative effects among SP-NRs. As a result, it delivers a high initial discharge capacity of 1246 mAh g-1 at 0.1 C and 918 mAh g-1 at 1 C, the low capacity decay rate per lap of 0.011% is achieved at a current density of 1 C after 1000 cycles. This research emphasizes the innovative structural design to provide a fresh trajectory for the further advancement of high-performance energy storage devices.

Integrated Design for Discrete Sulfur@Polymer Nanoreactor with Tandem Connection as Lithium–Sulfur Battery Cathodes

Apart from electrode material modification, architecture design and optimization are important approaches for improving lithium–sulfur battery performance. Herein, an integrated structure with tandem connection is constructed by confining nanosulfur (NS) in conductive poly(3,4‐ethylenedioxythiophene) (PEDOT) reaction chambers, forming an interface of discrete independent nanoreactor units bonded onto carbon nanotubes (noted as CNT/NS@PEDOT). The unique spatial confinement and concentration gradients of sulfur@PEDOT nanoreactors (SP‐NRs) can promote reaction kinetics while facilitating rapid polysulfide transformation and minimizing dissolution and diffusion losses. Meanwhile, overall ultrahigh energy input and output are achieved through tandem connection with carbon nanotubes, isolation with PEDOT coating, and synergistic multiplicative effects among SP‐NRs. As a result, it delivers a high initial discharge capacity of 1246 mAh g−1 at 0.1 C and 918 mAh g−1 at 1 C, the low capacity decay rate per lap of 0.011% is achieved at a current density of 1 C after 1000 cycles. This research emphasizes the innovative structural design to provide a fresh trajectory for the further advancement of high‐performance energy storage devices.

Design of symmetric supercapacitor based on Co3O4/Carboxymethyl cellulose nanoflakes with excellent cyclic stability

An advanced electrode material having fine micro/nano-architecture that provide unique qualities like ultra-high charge storage capabilities, high specific area and efficient pathway for ion insertion will always have superior position in the energy sphere. The prime motive of the present work is to fabricate carboxymethyl cellulose (CMC) encapsulated cobalt oxide nanoflakes as pioneered electrodes for supercapacitors. Utilizing a Faradaic candidate (cobalt oxide), which traps charges abundantly that leads to attracting capacitance (381 F g−1 at a specific current of 1 A g−1) with least charge transfer resistance (0.87 Ω). Make use of CMC as host that supports the composite via providing admirable cyclic life (100 % capacitance retention even after 5000 continuous charge/discharge cycles). Un-interrupted charge delivery that probably attributed to the formation of flaky architecture of cobalt oxide which was encapsulated by carbon matrix. As the end, a symmetric supercapacitor was designed using Co3O4/C nanoflakes as both positive and negative electrode. The fabricated two cell could capable of maintaining its stability of 95.87 % from its initial value after 5000 cycles of charge and discharge at a practical current density of 20 A g−1. The outcomes of the present study (three and two cell configuration as well) will open new gateways in energy regime for next generation supercapacitors.

Passivation Layers in Mg-metal Batteries: Robust Interphases for Li-metal Batteries.

In advanced batteries, interphases serve as the key component in stabilizing the electrolyte with reactive electrode materials far beyond thermodynamic equilibria. While an active interphase facilitates the transport of working ions, an inactive interphase obstructs ion flow, constituting the primary barrier to the realization of battery chemistries. Here, we present a successful transformation of a traditionally inactive passivating layer on Mg-metal anode, characteristic of Mg-metal batteries (MMBs) with typical carbonate electrolytes, into an active and robust interphase in the Li-metal scenario. By further strategically designing magnesiated Li+ electrolytes, we induce the in-situ development of this resilient interphase on Li-metal anodes, imparting enduring stability to Li-metal batteries (LMBs) with nickel-rich cathodes. We identify that the strong affinity between Mg2+ and anions in magnesiated Li+ electrolytes assembles ionic clusters with a bias for reducibility, thereby catalyzing the creation of anion-derived interphases rich in inorganic constituents. The prevalence of ionic clusters induced by magnesiation of electrolytes brought properties only available in high-concentration electrolytes, suggesting a fresh paradigm of tailing electrolytes for highly reversible LMBs. This article is protected by copyright. All rights reserved.