Exceptional Rate Performance Research Articles

Single‐Atom Cadmium‐N4 Sites for Rechargeable Li–CO2 Batteries with High Capacity and Ultra‐Long Lifetime (Adv. Funct. Mater. 25/2023)

Single-Atom Catalysts In article number 2213841, Zhenyu Sun, Yousung Jung, Xinyi Tan, and co-workers report, that single-atom cadmium with a Cd-N4 coordination structure enables rapid kinetics of both the discharge and recharge process when employed as a cathode catalyst, and thus facilitates exceptional rate performance in a Li-CO2 battery, even up to 10 A g−1, and remains stable at a high current density (100 A g−1).

High‐Mass‐Loading CoNi‐Layered Double Hydroxide Directly Grown on Brush‐like Cu/Carbon Cloth as High‐Areal‐Capacitance Supercapacitor Electrode

AbstractA combination of high mass loading and efficient utilization of electroactive materials is crucial for simultaneously enhancing the energy and power densities of energy storage devices. This is exemplified herein using cobalt nickel layered double hydroxides nanosheets (CoNi‐LDHs) directly grown on copper nanowires (Cu NWs) standing quasi‐vertically on carbon cloth (CC) to yield a multi‐core‐shell CoNi‐LDHs/Cu NWs/CC as the supercapacitor electrode that exhibits a high areal capacitance of 5.55 F cm−2 (corresponding to a gravimetric capacitance of 1209.15 F g−1) at a large current density of 10 mA cm−2. Such superior rate capability is attributed to the high packing density of CoNi‐LDHs in the electrode, benefitting from the large specific surface area of Cu NWs/CC. Additional contribution stems, on the other hand, from the facile charge transfer kinetics resulted from the elimination of binder from the electrode coupled with the mesopores between not only Cu NWs but also CoNi‐LDHs nanosheets, and the macropores between the carbon fiber of CC. Benefitting from such exceptional rate performance is the supercapacitor built on CoNi‐LDHs/Cu NWs/CC as the positive electrode coupled with bismuth subcarbonate (Bi2O2CO3) as the negative electrode capable of delivering outstanding power density of 13.31 mW cm−2 and energy density of 0.35 mWh cm−2.

Flower-like WS2@NS-C composite as a high-performance anode for Li-ion batteries

As a typical layered metal sulfide with larger interlayer spacing and higher theoretical capacity than graphite anode, WS2 has become one of the candidate materials to replace graphite anode. However, there are still problems such as significant capacity loss caused by high volume variation in the cycling process, dissolution of polysulfides intermediates and unfavorable Li+ diffusion dynamics. In this paper, the WS2 nano-flowers obtained by the solvothermal method were used as the matrix, which was coated with polymerized pyrrole at ambient temperature, and then calcined to form flower-like WS2 @N, S-co-doped carbon (WS2 @NS-C) composite. The synergy of flower-like hierarchical construction and NS co-doped carbon network effectively improves the electron/ion transport kinetics, creates variety of pseudo-capacitive reaction active sites, and might buffer the volume variation during repeated lithiation/delithiation and inhibit dissolution of polysulfide. Thus, it reveals exceptional stability and rate performance, reaching a specific capacity of 969 mA h g−1 after cycling 100 times at 0.1 A g−1 and 633 mA h g−1 after cycling 1000 times at 1.0 A g−1. This exceptional Li storage characteristic is attributable to the combined function of its flower-like construction and NS co-doped carbon network.

Hierarchical Composite from Carbon Nanofibers Wrapped SnS Core–Shell Nanoparticles as an Anode for Lithium-Ion Batteries

The significant capacity loss and pulverization caused by the dramatic increase in volume of Sn-based anodes during redox reactions severely limit their practical application in lithium-ion batteries. Herein, with the ultralong cycle life and high capacity Sn-based compounds (SnS-C/NS@CNFs), a self-supporting anode was prepared by electrospinning followed by the calcination scheme, which is a superb material for lithium storage since the buffer matrix reduces the volume expansion of Sn. In this strategy, SnS nanoparticles are scattered into a porous carbon framework using Sn-MOFs as a pore-forming template, which allows for easier extraction–insertion of Li-ions due to their inherent layered structure. Moreover, the nitrogen and S-doped carbon nanofibers not only serve as a barrier to impede the aggregation and volume expansion of SnS during cycling but also act as electrical pathways to enhance the conductivity of the electrodes. Having profited from the desirable nanostructures, the flexible three-dimensional cross-linked nanofibers were straightly used as a self-supporting anode for LIBs, displaying ultralong cycle life (455.8 mAh/g after 1000 cycles at 1 A/g) and exceptional rate performance (481 mAh/g at 2 A/g). This work offers a reliable and efficient method for fabricating flexible self-standing and durable electrodes.

Sodium Stoichiometry Tuning of the Biphasic-Nax MnO2 Cathode for High-Performance Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are promising alternatives for large-scale energy storage owing to the rich resource and cost effectiveness. However, there are limitations of suitable low-cost, high-rate cathode materials for fast charging and high-power delivery in grid systems. Herein, a biphasic tunnel/layered 0.80Na0.44 MnO2 /0.20Na0.70 MnO2 (80T/20L) cathode delivering exceptional rate performance through subtly regulating the sodium and manganese stoichiometry is reported. It delivers a reversible capacity of 87mAhg-1 at 4Ag-1 (33C), much higher than that of tunnel Na0.44 MnO2 (72mAhg-1 ) and layered Na0.70 MnO2 (36mAhg-1 ). It proves that the one-pot synthesized 80T/20L is able to suppress the deactivation of L-Na0.70 MnO2 under air-exposure, which improves the specific capacity and cycling stability. Based on electrochemical kinetics analysis, the electrochemical storage of 80T/20L is mainly based on pseudocapacitive surface-controlled process. The thick film of 80T/20L cathode (a single-side mass loading over 10mgcm-2 ) also has superior properties of pseudocapacitive response (over 83.5% at a low sweep rate of 1mVs-1 ) and excellent rate performance. In this sense, the 80T/20L cathode with outstanding comprehensive performance could meet the requirements of high-performance SIBs.

Single‐Atom Cadmium‐N4 Sites for Rechargeable Li–CO2 Batteries with High Capacity and Ultra‐Long Lifetime

AbstractThe rechargeable Li–CO2 battery shows great potential in civil, military, and aerospace fields due to its high theoretical energy density and CO2 capture capability. To facilitate the practical application of Li–CO2 battery, the design of efficient, low‐cost, and robust non‐noble metal cathodes to boost CO2 reduction/evolution kinetics is highly desirable yet remains a challenge. Herein, single‐atom cadmium is reported with a Cd‐N4 coordination structure enable rapid kinetics of both the discharge and recharge process when employed as a cathode catalyst, and thus facilitates exceptional rate performance in a Li–CO2 battery, even up to 10 A g−1, and remains stable at a high current density (100 A g−1). An unprecedented discharge capacity of 160045 mAh g−1 is attained at 500 mA g−1. Excellent cycling stability is maintained for 1685 and 669 cycles at 1 A g−1 and capacities of 0.5 and 1 Ah g−1, respectively. Density functional theory calculations reveal low energy barriers for both Li2CO3 formation and decomposition reactions during the respective discharge and recharge process, evidencing the high catalytic activity of single Cd sites. This study provides a simple and effective avenue for developing highly active and stable single‐atom non‐precious metal cathode catalysts for advanced Li–CO2 batteries.

Neuromorphic Carbon for Fast and Durable Potassium Storage

AbstractGraphitic carbon materials (GCs) are attractive as anodes for the industrialization of potassium ion batteries (PIBs). However, the poor cycle and rate performance of GC‐based anodes hinder the development of PIBs. In this study, inspired by the nervous system, neuromorphic GCs (NGCs) are designed to use as potassium anodes with high cycling stability and excellent rate performance. The inherent neuromorphic nature of NGCs enables fast signal transmission via multiwalled carbon nanotubes (MWCNTs), which serve as efficient pathways for electronic transmission. Meanwhile, the low‐stress properties of hollow carbon spheres effectively support the cycling stability of PIBs. As a result, NGC‐based potassium anodes achieved an unprecedented cycle life over 18 months (2400 cycles) with a reversible capacity of up to 225 mAh g−1 at a current density of 100 mA g−1. Moreover, the novel anode exhibits exceptional rate performance (73.6 mAh g−1 at 1 A g−1). The research presented here offers a practical and straightforward method for potassium's long‐term and high‐rate storage and beyond.

(1 1 1)-Oriented crystalline plane MnO loaded by biomass carbon separator to facilitate sulfur redox kinetics in lithium–sulfur batteries

Lithium-sulfur batteries have gained widespread attention due to their high theoretical energy density. However, the insulating properties of the charge–discharge products and slow kinetic transformation result in poor rate performance of these batteries. To address this issue, a study utilized Density-functional theory calculations to predict the formation of MnO on biochar derived from Phragmites australis. Additionally, the study investigated the adsorption energy and catalytic ability of MnO with different crystal planes for lithium polysulfide. Notably, the MnO (111) crystal plane exhibited the highest chemical adsorption energy. The study also analyzed the anchoring and catalytic method of lithium polysulfides. Furthermore, advanced analytical methods were employed to examine the structure and morphology of biomass carbon loaded with MnO, and a separator made from MnO-loaded biomass carbon was developed for use in Li-S batteries. The findings indicate that the separator substantially enhances the kinetic reaction, resulting in exceptional rate performance.

Ultrafast synthesis of battery grade graphite enabled by a multi-physics field carbonization

The typical synthesis of graphite requires carbonization at 2800 °C, which consumes a substantial amount of energy. We present a novel, sustainable and cost-effective method for synthesizing high-crystallinity graphite in 13 min at a low temperature of 1100 °C and a multi-physics field (MPF) carbonization coupling with a Ni catalyst. The MPF synergistically benefits from a thermal field, an electric field, and a pressure field in an MPF furnace at the lab scale. Molecular dynamics and differential charge density calculation indicated that the MPF carbonization facilitated exceptional kinetics, and considerably accelerated the breaking of the Ni-metal-catalyzed C-O bonds. The starch-derived graphite anode provided a reversible Li+ storage capacity of 370.7 mAh g−1, matching that of commercial graphite. It also demonstrates exceptional rate performance with a capacity of 103.3 mAh g−1 at an ultra-high current density of 30 A g−1 in diglyme-based Na-ion batteries and ultrastable cycling performance over 10,000 cycles at 2 A g−1. This method will shed some light on how to rapidly fabricate highly crystalline graphite by a energy-saving and low-cost route.

Synthesis and Nanostructure Investigation of Hybrid β-Ga2 O3 /ZnGa2 O4 Nanocomposite Networks with Narrow-Band Green Luminescence and High Initial Electrochemical Capacity.

The material design of functional "aero"-networks offers a facile approach to optical, catalytical, or and electrochemical applications based on multiscale morphologies, high large reactive area, and prominent material diversity. Here in this paper, the synthesis and structural characterization of a hybrid β-Ga2 O3 /ZnGa2 O4 nanocomposite aero-network are presented. The nanocomposite networks are studied on multiscale with respect to their micro- and nanostructure by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and are characterized for their photoluminescent response to UV light excitation and their electrochemical performance with Li-ion conversion reaction. The structural investigations reveal the simultaneous transformation of the precursor aero-GaN(ZnO) network into hollow architectures composed of β-Ga2 O3 and ZnGa2 O4 nanocrystals with a phase ratio of ≈1:2. The photoluminescence of hybrid aero-β-Ga2 O3 /ZnGa2 O4 nanocomposite networks demonstrates narrow band (λem = 504nm) green light emission of ZnGa2 O4 under UV light excitation (λex = 300nm). The evaluation of the metal-oxide network performance for electrochemical application for Li-ion batteries shows high initial capacities of ≈714 mAh g-1 at 100mA g-1 paired with exceptional rate performance even at high current densities of 4 A g-1 with 347 mAh g-1 . This study provides is an exciting showcase example of novel networked materials and demonstrates the opportunities of tailored micro-/nanostructures for diverse applications a diversity of possible applications.

Controllable synthesis of vanadium-doped nickel-chalcogenide/graphene cathodes and MnV2O6·2H2O/graphene anode for high-energy asymmetric supercapacitors

Exploring novel electrode materials with rational morphology and structure is crucial for the fabrication of high-performance supercapacitors. In this work, novel vanadium-doped nickel-chalcogenide/reduced graphene oxide cathodes (NiV-S/rGO and NiV-Se/rGO) and MnV2O6·2H2O/rGO anode are controllably prepared through a facile solvothermal method. Benefiting from the two-dimensional structure and desirable surface electronic environment, the graphene-supported NiV-X/rGO (X = S and Se) cathodes exhibit outstanding capacitive performance (1734.2 and 1577.2C·g−1 at 2 A·g−1), remarkable cycling stability and exceptional rate performance. Meanwhile, with the encapsulation of graphene protect layers, the MnV2O6·2H2O/rGO anode also shows a significantly enhanced specific capacity and superb cycling stability (95.8 % retention after 10,000 cycles). When assembled into asymmetric supercapacitors, the NiV-S/rGO//MnV2O6·2H2O/rGO and NiV-Se/rGO//MnV2O6·2H2O/rGO devices not only exhibit ultra-high energy densities (82.4 and 60.0 Wh·kg−1 at a power density of 800.0 W·kg−1), but also display superior cycling stabilities (91.5 % and 93.7 % retention after 10,000 cycles). These excellent properties demonstrate their potential application prospect in supercapacitor with high energy densities.

Mixed Ionic-Electronic Conduction Increases the Rate Capability of Polynaphthalenediimide for Energy Storage.

Conjugated polymers offer a number of unique and useful properties for use as battery electrodes, and recent work has reported that conjugated polymers can exhibit excellent rate performance due to electron transport along the polymer backbone. However, the rate performance depends on both ion and electron conduction, and strategies for increasing the intrinsic ionic conductivities of conjugated polymer electrodes are lacking. Here, we investigate a series of conjugated polynapthalene dicarboximide (PNDI) polymers containing oligo(ethylene glycol) (EG) side chains that enhance ion transport. We produced PNDI polymers with varying contents of alkylated and glycolated side chains and investigated the impact on rate performance, specific capacity, cycling stability, and electrochemical properties through a series of charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry measurements. We find that the incorporation of glycolated side chains results in electrode materials with exceptional rate performance (up to 500C, 14.4 s per cycle) in thick (up to 20 μm), high-polymer-content (up to 80 wt %) electrodes. Incorporation of EG side chains enhances both ionic and electronic conductivities, and we found that PNDI polymers with at least 90% of NDI units containing EG side chains functioned as carbon-free polymer electrodes. This work demonstrates that polymers with mixed ionic and electronic conduction are excellent candidates for battery electrodes with good cycling stability and capable of ultra-fast rate performance.

Designing Prussian blue coated iron electrode with exceptional cyclic and rate performance on potassium-ion storage

The larger size of K+ was a major hurdle that greatly restricted the rapid development of potassium-ion batteries (PIBs). Indiscriminate transplantation of lithium-ion storage materials in PIBs was sure to fail because of unexpected structural collapse caused by huge volume change and sluggish ionic kinetics in electrode. In this work, we designed an open-up core-shell structure, which contained inner iron core and outer Prussian blue (PB) shell. Electrons from external circuit preferred to get into conductive iron core and thereafter transmit to PB shell through large-angle scattering. Meanwhile, K+ ions from electrolyte could readily diffuse into PB lattice cavities and participate in redox reactions along with the scattered electrons. Thereupon, this core-shell structure could boost K-storage capability without sacrificing conductivity. It delivered a capacity of 402 mAh g−1 after 1000 cycles at 0.2 A g−1 and exhibited a capacity of 321 mAh g−1 at 5 A g−1.

InSitu Growth of Iron Sulfide on Fast Charge Transfer V2 C-MXene for Superior Sodium Storage Anodes.

Due to the upstream pressure of lithium resources, low-cost sodium-ion batteries (SIBs) have become the most potential candidates for energy storage systems in the new era. However, anode materials of SIBs have always been a major problem in their development. To address this, V2 C/Fe7 S8 @C composites with hierarchical structures prepared via an insitu synthesis method are proposed here. The 2D V2 C-MXene as the growth substrate for Fe7 S8 greatly improves the rate capability of SIBs, and the carbon layer on the surface provides a guarantee for charge-discharge stability. Unexpectedly, the V2 C/Fe7 S8 @C anode achieves satisfactory sodium storage capacity and exceptional rate performance (389.7mAhg-1 at 5Ag-1 ). The sodium storage mechanism and origin of composites are thoroughly studied via exsitu characterization techniques and first-principles calculations. Furthermore, the constructed sodium-ion capacitor assembled with N-doped porous carbon delivers excellent energy density (135Whkg-1 ) and power density (11kWkg-1 ), showing certain practical value. This work provides an advanced system of sodium storage anode materials and broadens the possibility of MXene-based materials in the energy storage.

Exploration of Charge Storage Behavior of Binder-Free EDL Capacitors in Aqueous Electrolytes.

Charge storage in electrochemical double-layer capacitors (EDLCs) is via the adsorption of electrolyte counterions in their positive and negative electrodes under an applied potential. This study investigates the EDLC-type charge storage in carbon nanotubes (CNT) electrodes in aqueous acidic (NaHSO4), basic (NaOH), and neutral (Na2SO4) electrolytes of similar cations but different anions as well as similar anions but different cations (Na2SO4 and Li2SO4) in a two-electrode Swagelok-type cell configuration. The physicochemical properties of ions, such as mobility/diffusion and solvation, are correlated with the charge storage parameters. The neutral electrolytes offer superior charge storage over the acidic and basic counterparts. Among the studied ions, SO4 2- and Li+ showed the most significant capacitance owing to their larger solvated ion size. The charge stored by the anions and cations follows the order SO4 2- > HSO4 - > OH- and Li+ > Na+, respectively. Consequently, the CNT//Li2SO4//CNT cell displayed outstanding charge storage indicators (operating voltage ∼0-2 V, specific capacitance ∼122 F·g-1, specific energy ∼67 W h·kg-1, and specific power ∼541 W·kg-1 at 0.5 A·g-1) than the other cells, which could light a red light-emitting diode (2.1 V) for several minutes. Besides, the CNT//Li2SO4//CNT device showed exceptional rate performance with a capacitance retention of ∼95% at various current densities (0.5-2.5 A·g-1) after 6500 cycles. The insights from this work could be used to design safer electrochemical capacitors of high energy density and power density.

A NaCrO2@C free-standing cathode via electrospinning for sodium-ion batteries.

A flexible free-standing cathode is innovatively constructed with NaCrO2 as the electrochemical active substance via an electrospinning technique. The as constructed NaCrO2@C flexible free-standing cathode exhibits exceptional rate performance (106 mA h g-1 at 10C) and cyclability (retention rate of 87.5% after 300 cycles at 0.2C). This work provides a brand-new perspective to the development of flexible free-standing cathodes.

Boosting the zinc storage of a small-molecule organic cathode by a desalinization strategy.

Organic materials offer great potential as electrodes for batteries due to their high theoretical capacity, flexible structural design, and easily accessible materials. However, one significant drawback of organic electrode materials is their tendency to dissolve in the electrolyte. Resazurin sodium salt (RSS) has demonstrated remarkable charge/discharge performance characterized by a voltage plateau and high capacity when utilized as a cathode in aqueous zinc-ion batteries (AZIBs). Unfortunately, the solubility of RSS as a sodium salt continues to pose challenges in AZIBs. In this study, we introduce an RSS-containing organic compound, triresazurin-triazine (TRT), with a porous structure prepared by a desalinization method from the RSS and 2,4,6-trichloro-1,3,5-triazine (TCT). This process retained active groups (carbonyl and nitroxide radical) while generating a highly conjugated structure, which not only inhibits the dissolution in the electrolyte, but also improves the electrical conductivity, enabling TRT to have excellent electrochemical properties. When evaluated as a cathode for AZIBs, TRT exhibits a high reversible capacity of 180 mA h g-1, exceptional rate performance (78 mA h g-1 under 2 A g-1), and excellent cycling stability with 65 mA h g-1 at 500 mA g-1 after 1000 cycles.

Construction of thickness-controllable bimetallic sulfides/reduced graphene oxide as a binder-free positive electrode for hybrid supercapacitors.

Devices for electrochemical energy storage with exceptional capacitance and rate performance, outstanding energy density, simple fabrication, long-term stability, and remarkable reversibility have always been in high demand. Herein, a high-performance binder-free electrode (3D NiCuS/rGO) was fabricated as a supercapacitor by a simple electrodeposition process on a Ni foam (NF) surface. The thickness of the deposited materials on the NF surface was adjusted by applying a low cycle number of cyclic voltammetry (5 cycles) which produced a thin layer and thus enabled the easier penetration of electrolytes to promote electron and charge transfer. The NiCuS was anchored by graphene layers producing nicely integrated materials leading to a higher electroconductivity and a larger surface area electrode. The as-fabricated electrode displayed a high specific capacitance (2211.029 F g-1 at 5 mV s-1). The NiCuS/rGO/NF//active carbon device can achieve a stable voltage window of 1.5 V with a highly specific capacitance of 84.3 F g-1 at a current density of 1 A g-1. At a power density of 749 W kg-1, a satisfactory energy density of 26.3 W h kg-1 was achieved, with outstanding coulombic efficiency of 100% and an admirable life span of 96.2% after 10 000 GCD cycles suggesting the significant potential of the as-prepared materials for practical supercapacitors.

Conjugated Azo Compounds as Active Materials for Rechargeable Sodium‐Metal Batteries with High‐Rate Performance

AbstractOrganic electrode materials have gained growing attention in the field of sodium‐metal batteries due to their rich reserves, flexibility, and environmental friendliness. However, organic small molecules suffer from poor stability in the electrolyte leading to the decay of battery capacity and reduced cycle life. To address these issues, we report a linear polymer p‐PADA with N=N and C=N as active centers. Its highly‐conjugated and polymerized structure endows the p‐PADA electrode stability, faster reaction kinetics, and exceptional rate performance. When the current density reaches 5 A g−1, p‐PADA still exhibits a specific capacity of 313 mAh g−1 after 1000 cycles. This work demonstrates that polymerization is an effective method to enhance the electrochemical properties of organic materials.

An ordered conductive Ni-CAT nanorods array as all-round polysulfide regulator for lithium-sulfur batteries

The effective suppression of polysulfide shuttle is indispensable for the commercialization of lithium-sulfur batteries (LSBs). In this work, an ordered conductive metal-organic framework (MOF) Ni-CAT nanorods array rooted on carbon nanotube film (Ni-CAT/CNTF) is proposed for this subject. The well-aligned MOF nanorods array possesses a unique vertical structure, presenting an incompact upper part and dense root, which guarantee the highly efficient adsorption and selective sieving towards polysulfides, respectively, as well as a fast Li+ transfer. What's more, the good electrical property and fully exposed Ni-based catalytic sites are qualified to boost the electrochemical kinetics. Consequently, LSBs with this fully functional MOF nanorods array exhibit an astonishing capacity of 1087 mAh g−1 and an extraordinary cyclability with a finite capacity-fading of only 0.026% per cycle for 1000 cycles at 1 C, along with an exceptional rate performance of 754 mAh g−1 at 5 C. Moreover, outstanding cycle and rate performance can be maintained under elevated sulfur loadings with a reduced electrolyte content. This work offers new insights into the rational design of polyfunctional nanostructures in LSBs.