Large-scale Energy Storage Devices Research Articles

Descriptor-Driven Computational Design of Bifunctional Double-Atom Hydrogen Evolution and Oxidation Reaction Electrocatalysts for Rechargeable Hydrogen Gas Batteries.

Rechargeable hydrogen gas batteries (RHGBs) have been attracting much attention as promising all-climate large-scale energy storage devices, which calls for low-cost and high-activity hydrogen evolution/oxidation reaction (HER/HOR) bifunctional electrocatalysts to replace the costly platinum-based catalysts. Based on density functional theory (DFT) computations, herein we report an effective descriptor-driven design principle to govern the HER/HOR electrocatalytic activity of double-atom catalysts (DACs) for RHGBs. We systematically investigate the d-band center variation of DACs and their correlations with HER/HOR free energies. We construct activity maps with the d-band center of DACs as a descriptor, which demonstrate that high HER/HOR electrocatalytic activity can be achieved with an appropriate d-band center of DACs. This work not only broadens the applicability of d-band center theory to the prediction of bifunctional HER/HOR electrocatalysts but also paves the way to fast screening and design of efficient and low-cost DACs to promote practical applications of RHGBs.

Synthesis and Electrochemical Performance of KVO/GO Composites as Anodes for Aqueous Rechargeable Lithium-Ion Batteries.

K0.25V2O5 (KVO) and K0.25V2O5/graphene oxide (KVO/GO) have been successfully synthesized by a chemical coprecipitation method and a subsequent calcination process. The structure and morphology of KVO and KVO/GO were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The as-obtained vanadate and vanadate modified by GO materials were used as anodes with LiMn2O4 as a cathode and saturated LiNO3 as an electrolyte to assemble an aqueous rechargeable lithium-ion battery (ARLB). The cyclic voltammogram curves of both KVO and KVO/GO electrodes exhibited three pairs of redox peaks corresponding to charge/discharge platforms. We found that a small amount of graphene oxide added improved the electrochemical performance more significantly than excess graphene oxide. The as-prepared KVO/GO//LiMn2O4 could not only improve the initial discharge capacity but could also reduce the attenuation at a high current density. Furthermore, the ARLB with a KVO/GO anode exhibited an excellent rate performance and super long cycle life. These good electrochemical properties of this new ARLB system actually provided feasibility for application in large-scale power sources and energy storage devices.

A bioconfined synthesis strategy of Sb2S3@N–doped carbon ribbons for boosting ultralong–life sodium storage

Reducing the synthesis costs of electrode materials and improving their electrochemical performance remain key issues regarding the application of sodium–ion batteries (SIBs) in large–scale energy storage devices. Antimony sulfide (Sb2S3) is a promising anode material for SIBs because of its high theoretical capacity. However, its poor electrical conductivity and volume expansion hinder its practical application. Aspergillus niger is an environmentally friendly, low–cost, and renewable fungus with a one–dimensional (1D) structure, it has high application value as a natural carbon source in energy storage materials. Herein, Sb2S3 composite N–doped carbon ribbons (Sb2S3@NCRs) are prepared using Aspergillus niger via the gas–phase sulfuration method. These Sb2S3@NCRs show excellent electrochemical performance as anode materials for SIBs. Using Na3V2(PO4)3 (NVP) as the counter electrode, here Sb2S3@NCRs//NVP is show to maintain a reversible specific capacity of 208 mAh·g−1 at 0.2 A g−1 after 100 cycles. In addition, the step–wise transformation and alloying reactions of Sb2S3@NCRs were verify using in situ X–ray diffraction (XRD) tests. This simple and inexpensive synthesis method provides a new strategy for creating other low–cost large–scale energy storage materials.

Carbon felt electrode modified by lotus seed shells for high-performance vanadium redox flow battery

Vanadium redox flow batteries (VRFBs) have attracted considerable attentions for their promising applications as large-scale energy storage devices. However, the widespread implementation of VRFBs is still hindered by the severe overpotentials of redox reactions, due to the poor electrochemical activities of conventional carbon felt (CF) electrodes. Herein, we present the fabrication of biomass lotus seed shells-modified CF (Bio-CF) electrode, which exhibits remarkable electrocatalytic effects on both the V2+/V3+ and VO2+/VO2+ redox reactions. The influences of auxiliary sucrose concentration and pyrolysis temperature were investigated to optimize the Bio-CF electrodes. Meanwhile, molecular dynamic simulations were employed to verify the experimental data. Furthermore, high performance VRFBs were achieved with the optimized Bio-CF electrode, affording high energy efficiency (83.14 %) and outstanding cycling stability under a current density of 100 mA cm−2. It is believed that the strategy to improve electrochemical performance of CF modified by cost-effective biomass materials provides a promising route for developing high performance VRFBs.

Stabilizing anionic redox processes in electrospun NiS2–based cathode towards durable aluminum-ion batteries

Rechargeable aluminum-ion batteries (AIBs) are receiving considerable attention as a desirable device for large-scale energy storage owing to high theoretical capacity and abundance of aluminum. However, due to strong charge of Al3+, the state-of-the-art AIBs often show sluggish electrode reaction kinetics and rapid capacity fading and the available cathode materials always demonstrate poor structural stability, thereby greatly hindering their practical use. NiS2 with anion redox species (S22– dimers) and favorable electronic conductivity is a promising cathode to boost the performance of AIBs in terms of reversible capacity, rate capability and cycling stability. Here, we report a systematic investigation of the Al storage behavior and mechanism of NiS2/S-doped carbon (NiS2/SC) cathode based on a series of electrochemical tests and ex situ measurements. We further develop electrospun NiS2/S-doped carbon@S-doped carbon nanofiber (NiS2/SC@SCNF) structure as the cathode of AIBs. The as-fabricated AIB delivers an unprecedented Al3+ storage performance with a stable capacity of 76 mAh/g at 0.5 A/g CV 500 cycles and a superior cycling Coulombic efficiency of 97 %. This study reveals that NiS2/SC@SCNF undergoes a reversible evolution of initial Al3+ insertion followed by anionic redox between S22– and S2–, paving the road for the futher development of NiS2–based cathodes for AIBs.

Construction of N-doped multichannel carbon nanofibers embedded with amorphous VS4 nanoparticles for potassium-ion batteries with ultralong-term cycling stability

Due to the low cost of potassium and its low redox potential, potassium ion batteries (KIBs) have been touted as viable candidates for large-scale energy storage devices. However, practical application of KIBs remains challenging due to a lack of suitable electrode materials capable of effectively storing large-sized K ions. The present article describes the successful preparation of a highly stable one-dimensional VS4/carbon composite comprising VS4 nanoparticles confined within N-doped multichannel carbon nanofibers (VS@NMCNF), using an electrospinning method followed by in-situ pyrolysis sulfidation, for use in KIBs. The porous structure of the carbon nanofiber is critical in allowing vanadium sulfide to have an amorphous crystal structure. Benefiting from the fast ion/electron transport, the amorphous nature of vanadium sulfide, and the structural robustness of the carbon matrix, the VS@NMCNF electrode exhibits a high reversible capacity (∼404.6 mAhg−1 at 0.5 A g−1), superior cycling stability for 4000 cycles, and an excellent rate capability (284.8 mAhg−1 at 2.0 A g−1). Additionally, the K-ion full cell composed of VS@NMCNF//Prussian blue demonstrates stable reversible capacity (233.1 mAhg−1 at 0.1 A g−1) and a high-rate capability (187.9 mAhg−1 at 2.0 A g−1).

Trash to treasure: Carbon-free ZnSe derived from waste zinc foil as a high-rate and long-life anode material enabling fast-charging sodium-ion batteries

A resource reuse strategy for recycling discarded zinc fragments from zinc-ion battery manufacturing is proposed to obtain carbon-free ZnSe anode material for sodium-ion batteries (SIBs), which are currently regarded as the solutions for future large-scale energy storage devices and distributed generation. Carbon-free ZnSe with micro-structure is conveniently prepared by calcining the discarded zinc fragment and selenium powder. ZnSe at optimal condition has an impressive initial Coulombic efficiency of up to 95.8% and a high capacity of 387.0 mAh g−1 at 0.1 A g−1. Providing a capacity of 142.5 mAh g−1 at 30 A g−1 shows the superb rate capability. Attractively, only 17.1 s is taken to complete a single charge, proving its application potential in fast-charging SIBs. Meanwhile, it also exhibits a conspicuous cyclability, corresponding to a capacity of 386.6 mAh g−1 at 2 A g−1 over 1600 cycles. Additionally, the full cell assembled Na3V2(PO4)2F3@reduced graphene oxide (rGO) cathode and ZnSe anode can light up 36 LEDs continuously with an ultimate energy density of 153.4 Wh Kg−1 and a maximum power density of 1108.5 W kg−1. This work aims to provide an available strategy for the synthesis of anode with high-rate performance and long cyclability for fast-charging SIBs.

The effect of conductive additives on electrochemical performance of LiFePO<sub>4</sub>-based lithium slurry batteries

<p indent="0mm">Lithium slurry batteries are promising large-scale energy-storage devices because of their low cost, long life, and independent scalability of energy and power capabilities. Electrode slurry is the main component of lithium slurry batteries and its conductive and rheological properties play an important role in the electrochemical performance of batteries. Herein, the types and amounts of conductive additives on the conductivity and rheology of LiFePO₄-based cathode slurry were investigated. By comparing the viscosity, suspension stability and conductivity of different cathode slurries, the 1.0 wt.% LFP–KB cathode slurry displayed a better electrochemical performance. Based on this cathode slurry, the lithium slurry batteries exhibited a stable cycle performance over 450 h. This work provides a guidance to select conductive additives for lithium slurry batteries.

Revealing the Reaction and Fading Mechanism of FeSe2 Cathodes for Rechargeable Magnesium Batteries.

Rechargeable Mg batteries (RMBs) are advantageous large-scale energy-storage devices because of the high abundance and high safety, but exploring high-performance cathodes remains the largest difficulty for their development. Compared with oxides and sulfides, selenides show better Mg-storage performance because the weaker interaction with the Mg2+ cation favors fast kinetics. Herein, nanorod-like FeSe2 was synthesized and investigated as a cathode for RMBs. Compared with microspheres and microparticles, nanorods exhibit higher capacity and better rate capability with a smaller particle size. The FeSe2 nanorods show a high capacity of 191 mAh g-1 at 50 mA g-1 and a good rate performance of 39 mAh g-1 at 1000 mA g-1 . Ex situ characterizations demonstrate the Mg2+ intercalation mechanism for FeSe2 , and a slight conversion reaction occurs on the surface of the particles. The capacity fading is mainly because of the dissolution of Fe2+ , which is caused by the reaction between Fe2+ and Cl- of the electrolyte during the charge process on the surface of the particles. The surface of FeSe2 is mainly selenium after long cycling, which may also dissolve in the electrolyte during cycling. The present work develops a new type of Mg2+ intercalation cathode for RMBs. More importantly, the fading mechanism revealed herein has considered the specificity of Mg battery electrolyte and would assist a better understanding of selenide cathodes for RMBs.

Design and Preparation of NiCoMn Ternary Layered Double Hydroxides with a Hollow Dodecahedral Structure for High-Performance Asymmetric Supercapacitors

Layered double hydroxides (LDHs) are prospective cathode materials for supercapacitors because of their outstanding theoretical specific capacitance and unique layered structure. However, the finite electroactive sites and cation species confine their practical application in supercapacitors. In this work, a hollow polyhedral ternary metallic Ni2CoMn1-LDH is prepared using zeolitic imidazolate framework-67 (ZIF-67) as the template. It has been found that the hollow dodecahedral structure constructed by thin nanosheets endows the Ni2CoMn1-LDH sample with abundant specific area and more ion-/electron-transport channels, which facilitate ion/electron transfer. Meanwhile, Ni2CoMn1-LDH can achieve the maximum synergistic effect of the different transition metals due to its optimal composition and content, which is conducive to improving the electrochemical behavior of supercapacitors. Benefiting from the advantages of their structure and composition, the as-prepared Ni2CoMn1-LDH electrode presents an excellent capacitance performance of 1634.4 F g–1 at 0.5 A g–1. Moreover, an asymmetric supercapacitor fabricated with a Ni2CoMn1-LDH cathode and an activated carbon (AC) anode reveals a good specific capacitance of 123.4 F g–1 at 1 A g–1 and a maximum energy density of 43.9 Wh kg–1 at a power density of 800 W kg–1. Therefore, constructing ternary LDHs with a unique hollow structure and optimal element composition has a promising prospect in the industrial application of supercapacitors and large-scale energy-storage devices.

Fabrication of Bipolar Plates from Thermoplastic Elastomer Composites for Vanadium Redox Flow Battery.

A vanadium redox flow battery (VRFB) is a promising large-scale energy storage device, due to its safety, durability, and scalability. The utilization of bipolar plates (BPs), made of thermoplastic vulcanizates (TPVs), synthetic graphite, woven-carbon-fiber fabric (WCFF), and a very thin pyrolytic graphite sheet (GS), is investigated in this study. To boost volumetric electrical conductivity, WCFF was introduced into the TPV composite, and the plate was covered with GS to increase surface electrical conductivity. Created composite BPs acquire the desired electrical conductivity, mechanical strength, and deformation characteristics. Those properties were assessed by a series of characterization experiments, and the morphology was examined using an optical microscope, a scanning electron microscope, and atomic force microscopy. Electrochemical testing was used to confirm the possibility of using the suggested BP in a working VRFB. The laminated BP was utilized in a flow cell to electrolytically convert V(IV) to V(V) and V(II), which achieved comparable results to a commercial graphite bipolar plate. Following these experiments, the laminated bipolar plates’ surfaces were examined using X-ray photoelectron spectroscopy, and no evidence of corrosion was found, indicating good durability in the hostile acidic environment.

Hydrated ammonium manganese phosphates by electrochemically induced manganese-defect as cathode material for aqueous zinc ion batteries

Aqueous zinc ion batteries (AZIBs) with the merits of low cost, low toxicity, high safety, environmental benignity as well as multi-valence properties as the large-scale energy storage devices demonstrate tremendous application prospect. However, the explorations for the most competitive manganese-based cathode materials of AZIBs have been mainly limited to some known manganese oxides. Herein, we report a new type of cathode material NH4MnPO4·H2O (abbreviated as AMPH) for rechargeable AZIBs synthesized through a simple hydrothermal method. An in-situ electrochemical strategy inducing Mn-defect has been used to unlock the electrochemical activity of AMPH through the initial charge process, which can convert poor electrochemical characteristic of AMPH towards Zn2+ and NH4+ into great electrochemically active cathode for AZIBs. It still delivers a reversible discharge capacity up to 90.0 mAh/g at 0.5 A/g even after 1000th cycles, which indicates a considerable capacity and an impressive cycle stability. Furthermore, this cathode reveals an (de)insertion mechanism of Zn2+ and NH4+ without structural collapse during the charge/discharge process. The work not only supplements a new member for the family of manganese-based compound for AZIBs, but also provides a potential direction for developing novel cathode material for AZIBs by introducing defect chemistry.

Effects of Valence States of Working Cations on the Electrochemical Performance of Sodium Vanadate

Supercapacitors have received much attention as large-scale energy storage devices for high power density and ultralong cycling life. In this work, sodium vanadate Na0.76V6O15/poly(3,4-ethylenedioxythiophene) (PEDOT) nanocables with deficient bridge oxygen at the interface (denoted Vo••-PNVO) have been tailored for supercapacitors through the in situ polymerization of 3,4-ethylenedioxythiophene and studied using three different electrolytes. Experiments and theoretical calculations reveal that all Na+, Zn2+, and Al3+ ions appear as hydrates in aqueous solutions but insert into the crystal structure as Na+ ions and Zn2+-H2O and Al3+-H2O hydrates, respectively. In comparison with the Zn2+-H2O and Al3+-H2O hydrates, Na+ ions with a smaller radius diffuse more quickly in Vo••-PNVO. Thus, Vo••-PNVO delivers better charge storage capability and stability when an electrolyte with Na+ ions is used. The results strongly suggest that an electrostatic interaction is significant in determining transport properties and storage capacities, rather than hydrate radii or valence states.

Long-Life Aqueous Zn-I2 Battery Enabled by a Low-Cost Multifunctional Zeolite Membrane Separator.

Aqueous zinc iodide (Zn-I2) batteries are promising large-scale energy-storage devices. However, the uncontrollable diffuse away/shuttle of soluble I3- leads to energy loss (low Coulombic efficiency, CE), and poor reversibility (self-discharge). Herein, we employ an ordered framework window within a zeolite molecular sieve to restrain I3- crossover and prepare zeolite molecular sieve particles into compact, large-scale, and flexible membranes at the engineering level. The as-prepared membrane can confine I3- within the catholyte region and restrain its irreversible escape, which is proved via space-resolution and electrochemical in situ time-resolution Raman technologies. As a result, overcharge/self-discharge and Zn corrosion are effectively controlled by zeolite separator. After replacing the typically used glass fiber separator to a zeolite membrane, the CE of Zn-I2 battery improves from 78.9 to 98.6% at 0.2 A/g. Besides, after aging at the fully charged state for 5.0 h, self-discharge is restrained and CE is enhanced from 44.0 to 85.65%. Moreover, the Zn-I2 cell maintains 91.0% capacity over 30,000 cycles at 4.0 A/g.

A pioneering melamine foam-based electrode via facile synthesis as prospective direction for vanadium redox flow batteries

Among the large-scale energy storage devices, vanadium redox flow batteries (VRFBs) are one of the most promising candidates. Carbon felt and graphite felt have been widely adopted as electrodes, however, poor electrochemical activities and low specific surface areas have limited their rollout in the market. Herein, a brand new type of three-dimensional N, P co-doped/reduced graphene oxide (rGO) coated carbonized melamine foam electrode has been proposed to address the above critical issues. Three-dimensional interconnected network structure provides smooth channels for the electrolyte, rGO can further improve the conductivity of the electrode, and heteroatom doping provides additional reaction sites for conversion reactions. Material and electrochemical characterizations demonstrate that the novel electrode possesses a high specific surface area and excellent electrochemical properties. Benefiting from the elaborate design of the electrode structure, the corresponding VRFB is able to yield an energy efficiency of 74.14% at the current density of 300 mA cm−2, and long-term cycling stability is also proved more than 200 consecutive charge–discharge cycles at 200 mA cm−2 without significant decay. All these show that the derivative of melamine foam has enormous advantages and wide application prospects as novel excellent electrode material.

Electrolyte Engineering Enables High Performance Zinc-Ion Batteries.

Zinc-ion batteries (ZIBs) feature high safety, low cost, environmental-friendliness, and promising electrochemical performance, and are therefore regarded as a potential technology to be applied in large-scale energy storage devices. However, ZIBs still face some critical challenges and bottlenecks. The electrolyte is an essential component of batteries and its properties affect the mass transport, energy storage mechanisms, reaction kinetics, and side reactions of ZIBs. The adjustment of electrolyte formulas usually has direct and obvious impacts on the overall output and performance. In this review, advanced electrolyte strategies are overviewed for optimizing the compatibility between cathode materials and electrolytes, inhibiting anode corrosion and dendrite growth, extending electrochemical stability windows, enabling wearable applications, and enhancing temperature tolerance. The underlying scientific mechanisms, electrolyte design principles, and recent progress are presented to provide a better understanding and inspiration to readers. In addition, a comprehensive perspective about electrolyte design and engineering for ZIBs is included.

Evidence for dual anions co-insertion in a transition metal chalcogenide cathode material NiSe2 for high-performance rechargeable aluminum-ion batteries

Rechargeable aluminum-ion batteries (RAIBs) are the subject of great interest owing to their attractive features like natural abundance, trivalent character, ultrahigh theoretical volumetric energy density and inherent safety, which endow RAIBs great prospect for large-scale energy storage devices. Nevertheless, the application of transition metal chalcogenide compounds as energy-dense cathode materials for RAIBs is currently hindered by their poor cycling stability and inadequate understanding of energy storage mechanisms. Here, we report dramatically enhanced aluminum storage performance from well-designed three-dimensional (3D) NiSe2 sponges wrapped with graphene oxide nanosheets (3D NiSe2 sponges@carbon composite). Electrochemical studies confirm that high capacity, superior rate capability and extraordinary cycling stability can be achieved from the prepared 3D NiSe2 sponges@carbon composite, rendering it a competitive cathode material for RAIBs. Moreover, combining comprehensive experimental measurements with systematic theoretical calculations, we show that dual anions co-insertion of AlCl4− and Cl− involved charge storage mechanism can be uncovered for the first time in NiSe2-based RAIBs. This new understanding of the aluminum storage mechanism provides chemical clues to further exploit the transition metal chalcogenide compounds electrode with substantial energy benefits.

One-pot synthesis of nanosized MnO incorporated into N-doped carbon nanosheets for high performance lithium storage

As potential anode materials for lithium-ion batteries, transition metal oxides have been extensively investigated due to their high theoretical capacity. Nevertheless, how to address rapid capacity degradation and improve rate capability is still a big challenge. Herein, nanosized MnO incorporated into N-doped carbon nanosheets (MnO/NCN) was rationally designed by a facile one-pot salt-templated synthesis method. The nanosized MnO particles (around 20 nm) were powerfully anchored on the ultrathin N-doped carbon nanosheets to build a high-efficiency electrons/ions hybrid conductive framework. In addition, based on the stable interfacial interaction between MnO and N-doped carbon nanosheets, the MnO/NCN hybrid exhibits great structural stability, thus delivering high reversible lithium storage capacity (719 mA h g−1 at 0.1 A g−1) and superior stability (497 mA h g−1 at 1 A g−1 over 1000 cycles). Besides, the assembled lithium-ion capacitor with MnO/NCN anode exhibits excellent energy-power characteristics (142 W h kg−1 at 412 W kg−1). Such impressive lithium storage performance demonstrates that the MnO/NCN electrode is promising for large-scale energy storage devices.

New-generation iron–titanium flow batteries with low cost and ultrahigh stability for stationary energy storage

New-generation iron–titanium flow battery (ITFB) with low cost and high stability is proposed for stationary energy storage, where sulfonic acid is chosen as the supporting electrolyte for the first time. In the design, the complexation between the sulfate ion and TiO2+ inhibits the hydrolysis of TiO2+ ions and improves the stability of the electrolyte. Combining the experimental characterization and the theory calculation, the stabilization mechanism of the electrolyte and the existing forms of TiO2+ ions in the electrolyte are explored deeply. Moreover, by electrodepositing metal Bi on the surface of the electrode, the electrochemical activity of the Ti3+/TiO2+ couple is effectively improved. As a result, the new-generation ITFB demonstrates coulombic efficiency of 99.7% and energy efficiency of 85.6% at the current density of 40 mA/cm2 and can run stably for more than 1000 cycles without obvious efficiency decay. Most importantly, after 1000 cycles, the discharge capacity still keeps 80% of the initial capacity, stating the extremely slow capacity decay (0.193 mAh/cycle). Furthermore, a low-cost and easily prepared sulfonated poly(ether ether ketone) (SPEEK) membrane, instead of the expensive Nafion membranes, is successfully used in the ITFB, feathering a very competitive cost advantage (less than 88.22 $/kWh). Therefore, considering the ultrahigh stability and low cost, it is easy for the new-generation ITFB to scale up and industrialize, thus new-generation ITFB is expected as a large-scale energy storage device in the foreseeable future.

Interface chemistry for sodium metal anodes/batteries: a review

Sodium metal batteries (SMBs), benefiting from their low cost and high energy densities, have drawn considerable interest as large-scale energy storage devices. However, uncontrollable dendritic formation of sodium metal anodes (SMAs) caused by inhomogeneous deposition of Na+ severely decreases the Coulombic efficiency, leads to short cycling life, and poses potential safety hazards, dragging SMBs out of practical applications. Electrolytes are attracting massive attention for not only providing ion transport channels but also exhibiting vital effects on interfacial compatibility and dendrite growth. In fact, the as-formed solid electrolyte interphase (SEI) has a great influence on the deposition and stripping process of SMAs. Moreover, Na plating process is accompanied by the generation of SEI, in which the electrolyte plays a vital role. Nevertheless, until now, the interaction among electrolyte-SEI-sodium dendrite has rarely been summarized. Herein, a fundamental understanding of sodium dendrite is concluded and the influence of the electrolyte and interface on Na+ deposition is emphasized. Furthermore, the outlook for constructing dendrite-inhibited SMAs is suggested.