Battery-type Materials Research Articles

Surface coating engineering of titanate anodes based on tannic acid-formaldehyde polymer chelating bismuth ions for advanced sodium-ion capacitors

As a battery-type anode material for sodium ion capacitors (SICs), titanate (H2Ti2O5·H2O, HTO) exhibits good rate capability due to its layered structure, easy to insert Na+ ions and low potential during sodium-ion storage. However, the structure is unstable due to the lattice distortion resulting from the irreversible embedment of Na+ in the process of sodium storage. So there is a significant mismatch between the dynamic reaction of the HTO anode and the capacitive cathode. Surface coating engineering is a useful strategy for stabilizing the HTO structure, which is critical for improving the kinetic response. In this work, a surface coating technique is designed to enhance the surface of HTO nanoarrays on titanium foil by using the oligomers of tannic acid formaldehyde polymer (TAF) chelated Bi3+ ions (Bi-TAF). As a binder-free anode, HTO coated with Bi-TAF (HTO@Bi-TAF) exhibits more excellent capacity (335.2 mA h g−1, 0.1 A g−1), rate capability (212.3 mA h g−1, 2.0 A g−1), and cycle stability (97 % capacity maintenance following 2000 cycles at 1.0 A g−1) than HTO and HTO coated with TAF (HTO@TAF). At the sweep rate of 1.0 mV s−1, the kinetic investigation reveals that the capacitance contribution of HTO@Bi-TAF is 86 %. The SICs exhibit a significant energy/power density (89.4 Wh kg−1/250 W kg−1). This work shows that the Bi-TAF polymer coating has a dual effect of rate capability improvement and structural protection on the prepared HTO. This results in a reasonable and effective surface coating strategy that provides outstanding rate capability and extended cycle performance of titanium-based anode materials for SICs.

Novel design of nickel cobalt boride nanosheets-decorated molybdenum disulfide hollow spheres as efficient battery-type materials of hybrid supercapacitors

Transition metal borides (TMBs) with high theoretical capacitances and excellent electronic properties have attracted much attention as a promising active material of supercapacitors (SCs). However, TMB nanoparticles are prone to conduct self-aggregation, which significantly deteriorates the electrochemical performance and structural stability. To address the severe self-aggregation in TMBs and improve the active material utilization, it is imperative to provide a conductive substrate that promotes the dispersion of TMB during growths. In this work, sheet-like nickel cobalt boride (NCB) was grown on molybdenum disulfide (MoS2) hollow spheres (H-MoS2) by using simple template growth and chemical reduction methods. The resultant NCB/H-MoS2-50 was observed with uniform NCB nanosheets structure on the surface of the H-MoS2 and stronger MB bonding. After optimizing the loading amount of H-MoS2, the optimal composite (NCB/H-MoS2-50) modified nickel foam (NF) exhibits a superior specific capacity (1302 C/g) than that of the NCB electrode (957 C/g) at 1 A/g. Excellent rate capability of 84.8% (1104 C/g at 40 A/g) is also achieved by the NCB/H-MoS2-50 electrode. The extraordinary electrochemical performance of NCB/H-MoS2-50 is credited to the unique nanosheet-covered hollow spheres structure for facilitating ion diffusion and versatile charge storage mechanisms from the pseudocapacitive behavior of H-MoS2 and the Faradaic redox behavior of NCB. Furthermore, a hybrid SC is assembled with NCB/H-MoS2-50 and activated carbon (AC) electrodes (NCB/H-MoS2-50//AC), which operates in a potential window up to 1.7 V and delivers a high energy density of 76.8 W h kg−1 at a power density of 850 W kg−1. A distinguished cycling stability of 93.2% over 20,000 cycles is also obtained for NCB/H-MoS2-50//AC. These findings disclose the significant potential of NCB/H-MoS2-50 as a highly performed battery-type material of SCs.

Insights of oxygen vacancies engineered structural, morphological, and electrochemical attributes of Cr-doped Co3O4 nanoparticles as redox active battery-type electrodes for hybrid supercapacitors

The global warming issue is spurring the development of renewable energy solutions, where supercapacitors are emerging as promising options for energy storage. Despite advancements in battery-type materials, doping is a practical approach to enhancing electrochemical performance. In this study, using the solution combustion method, we synthesized spinel Co3O4 nanoparticles doped with chromium (Cr) at 2.5 % and 5 % concentrations. The addition of Cr significantly modifies the structural, morphological, surface, and electrochemical properties of Co3O4 nanoparticles. Raman and X-ray photoelectron spectroscopy confirm that this doping method effectively regulates the oxygen vacancy defect level. Moreover, Cr dopants and oxygen vacancies modify electronic states, facilitating more accessible contact to active sites, improving electrical conductivity and more intricate redox chemistry. Notably, the 2.5 % Cr-doped Co3O4 configuration demonstrates substantially enhanced specific capacity (334.64 C g−1/92.95 mAh g−1 at 1 A g−1) and rate performance (59 %), surpassing those of 5 % Cr-doped Co3O4 and undoped Co3O4. Furthermore, the as-fabricated 2.5 % Cr-doped Co3O4//activated carbon (AC) hybrid supercapacitor (HSC) device exhibits a noteworthy energy density of 42.5 Wh kg−1 at 1295.73 W kg−1, withstanding 33.54 Wh kg−1 even at a power density of 5720.46 W kg−1. The HSC device showcases outstanding cyclic performance with 100 % capacity retention after 5000 cycles. Therefore, our work offers a viable way to improve the efficiency of hybrid supercapacitors by providing essential insights into the design of defect-engineered battery-type electrode materials.

Zinc manganite as an efficient battery-grade material for supercapattery devices

In the current context, supercapatteries emerge as highly desirable candidates capable of merging both energy and power density within a single device. Battery-type metal oxide materials, combined with capacitive-based materials, stand out as promising candidates for high-performance supercapatteries. This investigation centers on the synthesis of nanocrystalline ZnMn2O4 (ZMO) and CoMn2O4 (CMO) through a straightforward hydrothermal method, followed by their physico-electrochemical characterization. Electrochemical analysis reveals that ZMO exhibits notably enhanced charge storage capability compared to CMO. This superiority can be attributed to favourable electro-structural properties, and stable redox chemistry of ZMO. The real-time performance of ZnMn2O4 was further assessed by fabricating a hybrid asymmetric supercapattery device (ZnMn2O4||NrGO), which achieves a specific capacity of 232 C g−1 at a current density of 1 A g−1. The hybrid asymmetric device underwent rigorous stability testing for 4000 cycles at a current density of 2 A g−1, showcasing remarkable performance with a 92 % retention of its initial capacity. The device demonstrated a power density of 980 W kg−1 and an energy density of 63 Wh kg−1, highlighting its considerable promise in the field.

Novel ferrocene-based graphene oxide/Polypyrrole nanocomposites: Electro-capacitive properties study

In this research, we fabricated two novel ferrocene-modified graphene oxide (GO) nano-hybrids as electrode material for supercapacitors. Particularly, the physicochemical interaction of GO surface functional groups and as-synthesized ferrocenyl derivative, along with physical addition of polypyrrole (PPy) resulted in the preparation of high-performance battery-type capacitive materials. The GO-FBF1/PPy, and GO-FBF2/PPy, as final nanocomposites exhibited 229.43 and 269.57 mAhg−1 charge storage capacity, and capacity retention of 91 % and 93 % over 5000 CV cycles, respectively. Also, a symmetric supercapacitor (SSC) with GO-FBF2/PPy as both the anode and cathode exhibits exceptional cycling performance, with 95 % of its capacity remaining after 3000 cycles, and can be operated in a broad electrochemical window up to 1.6 V. Furthermore, our SSC device shows remarkable power and energy densities of 7859 W kg−1 and 123 Wh kg−1, respectively. For high-performance SCs, this research offers a way to improve the electrochemical characteristics of redox-active battery-type electrode materials.

Phase reconfiguration of heterogeneous CoFeS/CoNiS nanoparticles for superior battery-type supercapacitors

Developing advanced battery-type materials with abundant active sites, high conductivity, versatile morphologies, and hierarchically porous structures is crucial for realizing high-quality hybrid supercapacitors. Herein, heterogeneous FeS@NiS is synthesized by cationic Co doping via surface-structure engineering. The density functional theory (DFT) theoretical calculations are firstly performed to predict the advantages of Co dopant by improving the OH− adsorption properties and adjusting electronic structure, benefiting ions/electron transfer. The dynamic surface evolution is further explored which demonstrates that CoFeS@CoNiS could be quickly reconstructed to Ni(Co)Fe2O4 during the charging process, while the unstable structure of the amorphous Ni(Co)Fe2O4 results in partial conversion to Ni/Co/FeOOH at high potentials, which contributes to the more reactive active site and good structural stability. Thus, the free-standing electrode reveals excellent electrochemical performance with a superior capacity (335.6 mA h g−1, 2684 F g−1) at 3 A g−1. Furthermore, the as-fabricated device shows a quality energy density of 78.1 W h kg−1 at a power density of 750 W kg−1 and excellent cycle life of 92.1% capacitance retention after 5000 cycles. This work offers a facile strategy to construct versatile morphological structures using electrochemical activation and holds promising applications in energy-related fields.

Void space expanded hierarchical battery-type composite material for high-capacity hybrid supercapacitors

Synergetic modulation of battery-type materials with excellent electrochemical activity is an important feature to elevate the energy storage performance in the hybrid supercapacitors (HySCs). In this study, we synthesized a void space expanded nickel sulfide@nickel molybdenum oxysulfide on Ni foam (NixSy@NiMoOx-1Sy/Ni foam) using wet-chemical sulfurization technique. The growth solution, composed of sulfur ions, partially converts NiMo DHs into NiMoOx-1Sy and the Ni foam substrate into NixSy, resulting in the formation of a hybrid-composite. Increased mass-loading growth of NixSy@NiMoOx-1Sy/Ni foam and multi-oxidation states of nickel species in the composite were confirmed using the X-ray photoelectron spectroscopy analysis. The binder-free NixSy@NiMoOx-1Sy/Ni foam electrode was electrochemically cycled in aqueous KOH electrolyte, demonstrating battery-type redox behavior with enhanced capacity (310.6 mAh/g) compared to the NixSy/Ni foam (221.1 mAh/g) and NiMo DHs/Ni foam (142.5 mAh/g) electrodes, which could be ascribed to the improved electrical conductivity, adequate electrolyte diffusivity, and fast charge transfer properties. Furthermore, a two-electrode system based HySC was assembled using the battery-type NixSy@NiMoOx-1Sy/Ni foam and capacitive-type activated carbon, enabling a maximum energy density (58.8 Wh/kg) and power density (2666.7 W/kg) with good cycling stability and coulombic efficiency. The high-performance HySCs were used to power-up portable lighting devices, demonstrating their practical use in real-time applications.

Extrinsic Pseudocapacitive NiSe/rGO/g-C3N4 Nanocomposite for High-Performance Hybrid Supercapacitors.

Battery-type materials with ultrahigh energy density show great potential for hybrid supercapacitors (HSCs). In this work, we have developed a nickel selenide (NiSe)/reduced graphene oxide (rGO)/graphitic carbon nitride (g-C3N4) ternary composite as a promising positive electrode for hybrid supercapacitors (HSCs). The extended π-conjugated planar layers of g-C3N4 promote strong interconnectivity with rGO, which further enhances surface area, surface free energy, and efficient electron/ionic path. Additionally, it establishes clear ion diffusion pathways, serving as ion reservoirs during charge and discharge and facilitating efficient redox reactions. As a result, the NiSe/g-C3N4/rGO nanocomposite electrode displayed a specific capacity of 412.6 mA h g-1 at 1 A g-1. Later, the HSC device was assembled using the nanocomposite as the positive electrode and activated carbon as the negative electrode, which delivered an energy density of 65.2 Wh kg-1 at a power density of 750 W kg-1. Notably, the HSC device maintained excellent cyclic stability, preserving 93.3% of its initial performance and Coulombic efficiency of 86.6% for 10,000 charge-discharge cycles at 5 A g-1. These findings underscore the potential utility of NiSe/g-C3N4/rGO as a versatile and effective electrode material for the strategic development of HSC devices.

One-dimensional Fe7S8 nanorods encapsulated in N, S co-doped carbon shells accelerate lithium storage kinetics for lithium-ion capacitors

Abstract The slow kinetics of battery-type anode materials for lithium-ion capacitors (LICs) hinder their matching with capacitive-type cathodes. Designing anode materials with greater capacity and improved rate performance is a key to solving this challenge. Here, we fabricated one-dimensional N, S co-doped carbon encapsulated Fe7S8 nanorods to realize fast lithium storage kinetics and stable cycling performance. The matched Fe7S8@C//AC LICs achieved an extraordinary energy density of 101 Wh kg−1 and a power density of 3927 W kg−1.

Niobium boride (NbB2): Salt-templated synthesis, pseudocapacitive electrode and lithium-ion capacitor applications

Lithium-ion capacitors (LICs), which combine great power and energy density, have become promising energy storage and have been well studied recently. Developing novel battery-type anode materials is the key to mitigating the kinetic mismatch between the anode and cathode electrodes. In this paper, niobium diboride (NbB2) nanoparticles are synthesized via a salt-templated method and proposed for the first time as the anodes for LICs. NbB2 is a layered two-dimensional material similar to graphite, which is favorable to the intercalation and deintercalation of Li+. The NbB2 with high conductivity delivers outstanding long cycling stability (254.1 mAh g−1 after 800 cycles at 0.1 A g−1) and great rate capability. Moreover, a high-performance LIC is assembled employing the prepared NbB2 as anode and commercialized activated carbon (AC) as cathode, which can display an energy density of 68.76 Wh kg−1, a power density of 7.02 kW kg−1, and a capacity retention ratio of 98% after 10,000 cycles. The work presents the great potential of transition metal borides as electrode materials and accelerates the development of LICs.

Multifunctional Iron Selenate Sheath of Fe-Based Anode Achieving High-Rate Capacity-Durability Combination of Aqueous Hybrid Energy Storage Devices.

The introduction of battery-type cathode has been commonly considered a preferred approach to boost the energy density of aqueous hybrid energy storage devices (AHESDs) in alkalic systems, but AHESDs with both high energy density and power density are rare due to the great challenge in designing battery-type anode materials with high rate and durability comparable to capacitive-type carbon anodes. In this paper, a well-hydrated iron selenate (FeSeO) sheath is constructed around FeOOH nanorods by a facile electrochemical activation, demonstrating the unique multifunction in fasting charge diffusion, promoting the dissociation of H2O, and inhibiting the irreversible phase transition of FeOOH to inert γ-Fe2O3, which endow the hydrated sheath coated Fe-based anodes with an impressive rate capability and superior durability. Thanks to the comprehensive performance of this Fe-based anode, the assembled AHESD delivered a high energy density of 117Whkg-1 with the extraordinary durability of almost 100% capacity retention after 40000 cycles. Even at an ultrahigh power density of 27000Wkg-1, an impressive energy density of 65Whkg-1 can be achieved, which rivals previously reported energy-storage devices.

Polyaniline packed activated carbon as pseudocapacitive negative electrodes

Hybrid supercapacitors (HSCs) are attracting more attentions due to their potential high power and energy density. To exploring high capacity negative electrode materials, especially the capacitive materials, is more critical for further enhancing the energy density of HSC in comparing with more reported advanced battery-type positive materials. For perfect combination of electrochemical double layer and pseudocapacitive capacitance in negative electrode, the method of evenly filling polyaniline on nanopores of activated carbon is developed herein with keeping large surface area, the suitable ion-diffusion structure of activated carbon and further obtaining rich surface redox-active sites. The polyaniline packed activated carbons exhibit high specific capacitance (437.9 F g−1 at 0.5 A g−1) in negative voltage window (0 to −1.0 V), superior rate performance (378.0 F g−1 at 30 A g−1), and excellent capacitance retention even at a high mass loading and a high current density (326.5 F g−1 at 10 mg cm−2 and 20 A g−1). Additionally, an aqueous HSC based on the polyaniline packed activated carbon negative electrode and Ni-Co-LDH positive electrode presents higher energy density of 44.6 Wh kg−1 at a power density of 377.1 W kg−1. The present study presents novel method and materials for developing high performance capacitive negative electrode materials.

Metal ratio and bimetal nanoarchitectonics of ammonia-based fluoride complex induced nickel hydroxide and manganese oxide composites as active materials of an energy storage device

Nickel and manganese compounds are widely applied as efficient battery-type active materials for energy storage devices, due to high theoretical capacities and abundant redox states for generating redox reactions to store charges. Morphology plays significant roles on energy storage ability. Structure directing agent (SDA) is widely reported to have ability for modulating configurations of active materials and to achieve excellent surface properties. In this work, it is the first time to use NH4BF4 and NH4HF2 as structure directing agents for synthesizing nickel manganese compounds derived from ZIF67 as active materials of energy storage devices. Bimetallic compounds are composed of nickel hydroxide and manganese oxide, which presents the favorable two-dimensional flower-like structure with high surface area and abundant redox states. The largest specific capacitance (CF) of 1358.2 F/g corresponding to the capacity of 226.4 mAh/g are achieved for the bimetallic compound synthesized using the Ni to Mn precursor ratio of 1 to 1 (NiMn11). The energy storage device assembled using NiMn11 and reduced graphene oxide on Ni foams presents a maximum energy density of 11.45 Wh/kg at the power density of 0.35 kW/kg, and excellent long-term stability with the CF retention of 85.6% and Coulombic efficiency of 87.5% after 10,000 cycles.

Electrochemical surface reconstruction of nickel cobalt pyrophosphate to Ni/Co-hydroxide-(oxy)hydroxide: an efficient and highly durable battery-type supercapacitor electrode material

Highly durable porous battery-type supercapacitor charge storage material derived through electrochemical surface reconstruction of nickel cobalt pyrophosphate.

A multi-interface bimetallic sulfoselenide–selenite heterojunction as a battery-type cathode for high-performance supercapacitors

A bimetallic sulfoselenide–selenite heterojunction of (Ni,Co)(Se,S)2/(Ni,Co)SeO3 was prepared from LDH-based templates as high-capacity battery-type materials for hybrid supercapacitors.

High pseudocapacitance electrode enabled by heterovalent doping and surface coating for rapid charge storage

With admirable energy storage kinetics and high capacitance, pseudocapacitive electrodes have been regarded as promising candidates to replace active carbon materials for next-generation supercapacitors. Unfortunately, these materials usually present lower capacitance compared to the Ni/Co-based battery-type materials, and insufficient cycling lifespans due to repeat surface redox reactions. Here, we employ Fe doping and surface coating to construct a high-capacitance robust pseudocapacitive WO3-based electrode (10-Fe-WO3/PANI). Heterovalent doping breaks the octahedral symmetry of WO3 and effectively boosts the reversible capacitance of WO3 due to Jahn-Teller distortion, creating abundant active sites for energy storage. Polyaniline (PANI) coating enhances the structural durability and ion diffusion kinetics of WO3 in the acid electrolyte, promoting long-term cycling performance. As expected, the optimized electrode can deliver a high specific capacitance of 4006 mF cm−2 at 5 mA cm−2, which is about five-fold higher than that of a pure WO3 electrode (733.7 mF cm−2) and can steadily work for 10,000 cycles without apparent capacitance decay. The full device using polypyrrole (PPy) as the cathode exhibits intriguing energy/power density and cycling lifespans, demonstrating the application potential of this material. This work may enlighten the development of cationic doping and advanced pseudocapacitive materials design in electrochemical energy storage fields.

Heterostructured Ni2P/NiMo-layered double hydroxide nanoarrays with enriched redox active sites for supercapacitors

The electroactivity and cyclic stability of transition metal phosphides (TMPs) for supercapacitors are restricted by inadequate redox active sites and huge volume changes during the charging/discharging process. Herein, a three-dimensional (3D) porous Ni2P/NiMo-layered double hydroxide (NiMo-LDH) heterostructure with large specific surface and abundant pore channels is explored as a self-supporting supercapacitor electrode. The well-defined hierarchical pore structure can offer numerous electroactive sites and short ion/electron pathways. The generation of heterointerfaces between multi-dimensional Ni2P and two-dimensional (2D) NiMo-LDH nanosheets endows the hybrid composite with improved electrical conductivity and structural robustness. Consequently, the special nanoarchitecture design achieves a specific capacity of 198.6 mAh g−1 (2.28 mAh cm−2) at 1 A g−1 and an impressive rate performance of 78.3% at 20 A g−1. More importantly, the assembled Ni2P/NiMo-LDH//orange peel-derived porous carbon (OPC) asymmetric supercapacitor (ASC) device delivers a remarkable specific energy of 63.7 Wh kg−1 at a specific power of 1138.3 W kg−1 and long-term cycling stability (91.7% over 10,000 cycles). The research highlights that the hybridization of TMPs and other nanostructured battery-type materials may produce a synergistic effect and boost the capacitive properties.

A novel hybrid electrode composited Ni-Sn alloys with SnOx for supercapacitors

Hybrid electrodes consisting of battery-type and capacitive-type materials show excellent electrochemical performance, which have attracted much attention for high-performance supercapacitors recently. This work proposes a novel strategy to fabricate Ni-Sn alloys enhanced hybrid electrodes by an ingenious one-step thermal treatment process, and the obtained Ni@a-SnOx samples are composed of SnOx, Ni and Ni-Sn alloys (c-Ni3Sn, h-Ni3Sn). Thereinto, the existence of Ni-Sn alloys would enhance the electrochemical performance of samples due to their high electrical conductivity as well as extra Faradaic redox reactions. During electrochemical measurements, the Ni@a-SnOx electrodes exhibit both capacitive-type and battery-type behaviors, and the maximum specific capacitance achieves 29.6 mAh·g−1 (or 177.6 F·g−1) at a current density of 1 A·g−1, which shows outstanding rate capability. Besides, capacitance retention of the optimal Ni@a-SnOx sample increases first and then decreases slightly during 1000 charge-discharge cycles, reaching 2.7 times higher than the original value after 600 cycles, implying superior electrochemical performance. Furthermore, the facile method could be extended to fabricate other kinds of alloy-enhanced metal oxide electrodes for new generation supercapacitors in the future.

Inhabiting Inactive Transition by Coupling Function of Oxygen Vacancies and Fe-C Bonds Achieving Long Cycle Life of Iron-Based Anode.

Fe-based battery-type anode materials with many faradaic reaction sites have higher capacities than carbon-based double-layer-type materials and can be used to develop aqueous supercapacitors with high energy density. However, as an insurmountable bottleneck, the severe capacity fading and poor cyclability derived from the inactive transition hinder their commercial application in asymmetric supercapacitors (ASCs). Herein, driven by the "oxygen pumping" mechanism, oxygen vacancy-rich Fe@Fe3 O4 (v) @Fe3 C@C nanoparticles are developed that consist of a unique "fruit with stone"-like structure and exhibit enhanced specific capacity and fast charge/discharge capability. Experimental and theoretical results demonstrate that the capacity attenuation in conventional iron-based anodes is greatly alleviated in the Fe@Fe3 O4 (v) @Fe3 C@C anode because the irreversible phase transition to the inactive γ-Fe2 O3 phase could be inhibited by a robust barrier formed by the coupling of oxygen vacancies and Fe-C bonds, which promotes cycle stability (93.5% capacity retention after 24,000 cycles). ASC fabricated using this Fe-based anode is also observed to have extraordinary durability, achieving capacity retention of 96.4% after 38,000 cycles, and a high energy density of 127.6 W h kg-1 at a power density of 981 W kg-1 . This article is protected by copyright. All rights reserved.

Utilization of PET derived hard carbon as a battery-type, higher plateau capacity anode for sodium-ion and potassium-ion batteries

Trash to Treasure is a less energy-intensive approach for upcycling plastic waste into value-added products to generate sustainable, cost-effective, eco-friendly materials. The carbonization of polyethylene terephthalate (PET) via a single-step process into hard carbon (HC) delivers a high-performing anode material for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). Direct pyrolysis of PET waste increases the interlayer spacing with partially closed slit-shaped micro and mesopores that significantly improves the lower potential plateau-based capacity to 68% of the total capacity, validating a battery-type anode material. The HC carbonized at 1000℃ delivers a reversible capacity of 337 mAh/g with capacity retention of 88% after 100 cycles at 30 mAh/g. The HC exhibits 80% capacity retention even after 1000 cycles at a 1C rate and is promising for fast cycling-high power density applications. In PIBs, the HC carbonized at 800℃ performs the best and shows a reversible capacity of 305 mAh/g, with a battery-type low voltage plateau contribution of 32%. The charge storage mechanism in SIBS and PIBs follows a three-stage storage mechanism, i.e., adsorption, intercalation, and pore-filling.