Superior High-rate Performance Research Articles

Fabrication of robust mechanical NiCo nanocubes for lithium metal anode with superior high rate performance

The incorporation of a conductive three-dimensional (3D) scaffold in lithium metal anodes (LMAs) represents one of the most effective strategies for mitigating the uncontrolled formation of lithium dendrites. In this study, a promising substrate is fabricated by one-step co-deposition of NiCo nanocubes on carbon fiber composite (CFC). The bimetallic nanocubes offer an abundance of lithiophilicity sites and exhibit exceptional mechanical properties, thereby enhancing the stability of the electrode. By incorporating pyridine and pyrrole nitrogen, along with the synergistic effect of bimetal ions, the stability of solid electrolyte interphase (SEI) film is also enhanced, interface resistance is reduced, and uniform lithium metal deposition is achieved, effectively inhibiting dendrite growth especially at high current densities, with a lifespan up to 5660 h at ultra-high current density up to 40 mA cm−2. When paired with LiFePO4, the full battery exhibits satisfied dynamic stability and ultra-long cycle stability during repeated shelving, maintaining good capacity retention after 2890 cycles at 1C. This work provides a new idea for the practical application of lithium metal battery.

High-Capacity, High-Rate Nanosized Bismuth-Antimony Embedded in N-Doped Carbon Matrix Via Facile Pyrolysis As Anodes for Advanced Li Storage

Antimony (Sb) is an attractive anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity (660 mAh g–1). Nevertheless, it suffers from huge volume expansion and severe particle pulverization during lithiation/delithiation processes, which leads to poor cycling performance. Herein, to address this matter, a composite of bismuth-antimony alloy nanoparticles embedded in N doped-carbon coating (BiSb@NC) is fabricated via a simple pyrolysis method. The design of bimetallic Bi-Sb solid solutions is possible at any molar ratio. The coupled pair, metallic Bi itself, does not only provide high volumetric capacity (3765 mAh cm–3) and low working potential (0.8 V hereafter vs. Li+/Li) but could also synergistically buffer the volume fluctuation due to the different working potentials between the two alloys. Nanosized BiSb alloys can enhance the reaction kinetics through shortened Li+-ion diffusion pathways. Additionally, the N-doped carbon coating also effectively cushions the volume changes of BiSb and maintains effective conductive networks during extended alloying/dealloying reactions with Li+ ions. As a result, the BiSb@NC anode achieves a high reversible capacity of 550 mA h g–1 after 100 cycles at 100 mA g–1 and superior high-rate performance of 350 and 220 mA h g–1 at 2 and 5 A g–1, accordingly despite its high BiSb loading (82 wt%).

Innovative High-Voltage Cathode Architectures for Doped Ammonium Vanadium Oxide: Overcoming Limitations and Boosting Energy Density

Sodium-ion batteries are emerging as a feasible substitute to lithium-ion batteries due to natural abundance and cost of their raw materials. Cathode materials with high operating voltage window are highly investigated in order to attain a high specific capacity and energy density. Because of its larger ionic size and lower standard electrochemical potential of Na, research on suitable cathodes with rich electrochemistry and high energy density is of utmost importance. NH4V4O10 (Ammonium Vanadium Oxide) is one such cathode with rich electrochemistry in terms of high sodium-ion storage along with a low-cost proposition. It is synthesized feasibly using a one-step hydrothermal process at lower temperatures (160o). However, the low conductivity and structural distortion during extended cycling pose a significant challenge. In this study, we present a high-rate cathode based on NH4V4O10, which employs a doping strategy to address the structural changes that cause distortion, while simultaneously improving ionic conductivity and electrochemical performance. By introducing dopants into NH4V4O10, the mobility of carriers is increased as the lattice spacing is expanded. This modification facilitates easier movement of Na-ions within the crystal lattice during electrochemical cycling, ultimately leading to enhanced Na-ion diffusion. As a result, the doped NH4V4O10 electrode exhibits superior high-rate performance compared to the pristine NH4V4O10. Furthermore, this doped NH4V4O10 cathode can be operated effectively at High voltage (1 V to 4.2 V ) and thus increasing the energy density. In addition to enhancing the ionic conductivity and Na-ion diffusion coefficient, the incorporation of dopants into NH4V4O10 also results in improved morphology, which contributes to the maintenance of a stable structure. As a result, the doped- NH4V4O10 cathode exhibits a specific capacity of 250 mAh/g with 0.1 A/g after 100 cycles, along with a Coulombic efficiency of 98%, whereas NH4V4O10 only achieves a 70% efficiency and within a restricted working potential window. With its unique properties, including superior conductivity, high Na-ion diffusion coefficient, and stable capacity over extended cycling, this newly modified doped NH4V4O10 material holds promise as a novel class of cathode for next-generation high-performance sodium-ion batteries.

Morphology-tuned synthesis of MgCo2O4@NiO arrays coated on nickel foam for high-rate supercapacitor electrode

In this study, hydrothermal synthesis and calcination strategies were used to grow MgCo2O4@NiO composites on nickel foam. NiO nanosheets were loaded onto rod-shaped MgCo2O4 to form a 3D MgCo2O4@NiO structure, which can intimate electrode/electrolyte contact and accelerate electron transport during a Faradic reaction. The MgCo2O4@NiO electrode exhibits superior high-rate electrochemical performance, which provides optimal capacities for the preparation. The cathode material exhibited a maximum capacity of 900.0 C g−1 at a current density of 1 A g−1. The composite material showed good long-cycle stability, retaining 96.3 % of capacities after 3000 cycles. The assembled supercapacitor achieved an energy density of 39.5 Wh kg−1 at a power density of 850.0 W kg−1. This study suggests that MgCo2O4@NiO is an encouraging candidate for the next-generation energy storage devices.

C-Doped LiVO3 Honeycombs Derived from the Biomass Template Strategy for Superior Lithium Storage.

LiVO3 as a prospective anode for lithium-ion batteries has drawn considerable focus based on its superior ion transfer capability and relatively elevated specific capacity. Nevertheless, the inherent low electrical conductivity and sluggish reaction kinetics hindered its commercial application. Herein, C-doped LiVO3 honeycombs (C-doped LiVO3 HCs) are designed via introducing low-cost and scalable biomass carbon as a template, and the influence of the structure on the lithium storage property is systematically studied. The prepared C-doped LiVO3 HC electrode delivers a high reversible capacity of 743.7 mA h g-1 at 0.5 A g-1 after 400 cycles and superior high-rate performance with an average discharge capacity of 420.8 mA h g-1 even at 5.0 A g-1. The remarkable comprehensive electrochemical performance is attributed to the high electrical conductivity caused by carbon doping and rapid ion transport triggered by the honeycomb structure. This work may offer a rational design on both the hierarchical structure and doping engineering of future battery electrodes.

Graphene oxide-assisted fabrication of mesoporous oxygen-deficient VO2 nanobelts for enhanced Zn2+ storage

Rechargeable aqueous zinc-ion batteries (ZIBs) are regarded as promising devices for large-scale stationary energy storage. However, developing ideal cathode materials confronts great challenges. Herein, a novel graphene oxide (GO)-assisted strategy is proposed to synthesis mesoporous VO2/G nanobelts with abundant oxygen defects for high-performance Zn2+ storage. The oxygen vacancies and mesopores facilitate Zn2+ insertion/extraction process. After an in-situ electrochemical activation at around 1.5 V, the monoclinic VO2 transforms to layered V2O5·nH2O, delivering an extremely high reversible capacity of 731 mAh/g (0.1 A/g). In addition, superior high-rate and cycling performances are also achieved.

Decorating Phosphorus Anode with SnO2 Nanoparticles To Enhance Polyphosphides Chemisorption for High-Performance Lithium-Ion Batteries.

Phosphorus has been regarded as one of the most promising next-generation lithium-ion battery anode materials, because of its high theoretical specific capacity and safe working potential. However, the shuttle effect and sluggish conversion kinetics hamper its practical application. To overcome these limitations, we decorated SnO2 nanoparticles at the surface of phosphorus using an electrostatic self-assembly method, in which SnO2 can participate in the discharge/charge reaction, and the Li2O formed can chemically adsorb and suppress the shuttle of soluble polyphosphides across the separator. Additionally, the Sn/Li-Sn alloy can enhance the electrical conductivity of the overall electrode. Meanwhile, the similar volume changes and simultaneous lithiation/delithiation process in phosphorus and SnO2/Sn are beneficial for avoiding additional particle damage near two-phase boundaries. Consequently, this hybrid anode exhibits a high reversible capacity of ∼1180.4 mAh g-1 after 120 cycles and superior high-rate performance with ∼78.5% capacity retention from 100 to 1000 mA g-1.

Facile synthesis of nitrogen-doped graphene, and its advanced electrochemical activity toward efficient lithium ion storage

Nitrogen-doped graphene (N-Graphene) has been extensively researched as the anode material for lithium-ion batteries, as the nitrogen doping provides massive active sites and improves the electrical conductivity and the ion diffusion kinetics, thus, significantly enhancing the lithium storage performance with reversible capacity and cycling stability. However, the high-rate performance and cyclability of the N-Graphene-based anodes are still to be achieved for fast-charging applications. Here, a new N-Graphene was successfully fabricated by annealing the commercial few-layer graphene with dicyandiamide. Along with the plenty of defects in the pristine graphene sheets, the doping of nitrogen effectively reduces the resistance and increases pore volume and the diffusion coefficient. Consequently, the N-Graphene anode exhibits outstanding lithium storage performance with superior high-rate performance and remarkable long-term capability (up to 10,000 cycles at 15 A g[Formula: see text] with a reversible capacity of 133 mAh g[Formula: see text]). Further kinetic analysis reveals that this excellent electrochemical behavior during the rapid discharge/charge operations can be attributed to the enhanced diffusion-controlled and surface capacitive storages. Our process may lead to an alternative way for producing competitive N-Graphene anode materials for efficient lithium ion storage.

Boosting high-rate Zn-ion storage capability of α-MnO2 through Tri-ion co-intercalation

Aqueous rechargeable zinc-ion batteries (ARZIBs) have become a research hotspot in recent years because of their high energy density, low cost, rich zinc resources, and high safety. However, defects in the electrochemical performance of cathode materials become a stumbling block for the practical application of ARZIBs. The α-MnO2 cathode material is attracted attention due to its high theoretical capacity and scalable industrial manufacturing, but inherently low electron conduction and poor ion mobility affect transport kinetics, resulting in low capacity and rate capabilities. Here, for the first time, a new α-MnO2 cathode is prepared with co-intercalation of K+, Co2+ and Al3+ through a one-step solution co-precipitation strategy. Taking advantage of the synergistic effect of alkali metal ions and transition metal ions, modified α-MnO2 shows superior high-rate performance (a capacity of 100 mAh g−1 after 800 cycles at 5.0 A g−1) and stable crystal structure. This result is attributed to the enlarged tunnel structure brought about by multi-ion intercalation, which promotes the rapid migration of Zn2+ and improves the transport kinetics. On the basis of the new design of tri-ion co-intercalation, it is hoped that this research will provide theoretical guidance for the preparation of high-capacity Mn-based cathode active materials for ARZIBs.

温度调控制备锡或二氧化锡@中空多孔碳纳米纤维电极用于个性化定制锂离子电池

Lithium-ion batteries (LIBs) have been widely used as grid-level energy storage systems to power electric vehicles, hybrid electric vehicles, and portable electronic devices. However, it is a big challenge to develop high-capacity electrode materials with large energy storage and ultrafast charging capability simultaneously due to the sluggish charge carrier transport in bulk materials and fragments of active materials. To address this issue, composite electrodes of SnO2 nanodots and Sn nanoclusters embedded in hollow porous carbon nanofibers (denoted as SnO2@HPCNFs and Sn@HPCNFs) were respectively constructed programmatically for customized LIBs. Highly interconnected carbon nanofiber networks served as fast electron transport pathways. Additionally, the hierarchical hollow and porous structure facilitated rapid Li-ion diffusion and alleviated the volume expansion of Sn and SnO2. SnO2@HPCNFs delivered a remarkably high capacity of 899.3 mA h g−1 at 0.1 A g−1 due to enhanced Li adsorption and high ionic diffusivity. Meanwhile, Sn@HPCNFs displayed fast charging capability and superior high rate performance of 238.8 mA h g−1 at 5 A g−1 (∼10 C) due to the synergetic effect of enhanced Li-ion storage in the bulk pores of Sn and improved electronic conductivity. The investigation of the electrochemical behaviors of SnO2 and Sn by tailoring the carbonization temperature provides new insight into constructing high-capacity anode materials for high-performance energy storage devices.

Stabilizing structure and voltage decay of lithium-rich cathode materials

A major challenge in the discovery of high-energy lithium-ion batteries (LIBs) is to control the voltage stability and Li+ kinetics in lithium-rich layered oxide (LrLO) cathode materials. Although these materials can provide a higher specific capacity compared to the current industrially used cathodes, the substantial voltage decay and low Li+ diffusion during long term cycling is a serious reason for hindering their practical applications. In order to suppress the voltage decay in lithium-rich cathode materials, herein we introduce the Ti doping into Li1.2Mn0.56Ni0.17Co0.07O2 cathodes. Also, the influence of Ti doping on the crystalline internal structure, surface chemistry, cycling retention, and Li+ kinetics of Li1.2Mn0.56Ni0.17Co0.07O2 cathodes have been focused in this work. The Ti doping effectively enhances the structural/interfacial stability of the cathode and accelerates the Li+ kinetics by expanding the lattice, thereby significantly realizing its voltage/cycling stability and high-rate capability. Experimental results show that Ti-doped LrLO (1% Ti) has achieved high electrochemical kinetics as the discharge cycle retention increased from 61.58% (pristine) to 80.0% after 180 cycles at 1 C, with 150.3 mAh g−1 showing superior high-rate performance at 5C. Ex-situ XRD results confirmed the better structural stability of Ti-doped LrLO after high-rate electrochemical cycling. Our findings provide a suitable element doping strategy for regulating the voltage decay and cycle retention of LrLO, thus promoting their real-world application in future batteries.

Rose-like VS2 Self-Assembled from Nanosheets with Superior Sodium Storage Performance

Recently, sodium ion batteries (SIBs) have exhibited great application potential in the area of renewable energy storage. However, developing anodes for SIBs with excellent cycling stability and high capacity is a great challenge. In recent years, VS2 attracts more attention due to its high specific capacity. In this work, three-dimensional (3D) rose-like VS2 self-assembled from nanosheet was prepared via a solvothermal method using N-methylpyrrolidone as the solvent. The special 3D structure facilitates electron/Na+ transport and can relieve the volume change during Na+ insertion/extraction. Benefitting from the 3D self-assembled structure, VS2 exhibits outstanding cycling stability at high current density. Even when tested at 5 A g−1, the 3D VS2 electrode can maintain a high capacity of 565 mA h g−1 after 350 cycles. Through pseudo-capacitance contribution calculation, we speculate that the high capacitance contribution confers the superior high rate performance to the VS2. This work sheds a new light on the design and preparation 3D VS2, which can be utilized as an excellent anode for SIBs.

Sulfur-doped graphene promoted Li4Ti5O12@C nanocrystals for lithium-ion batteries

Herein, sulfur-doped graphene modified Li 4 Ti 5 O 12 @C nanocomposite (SG-T@C) has been firstly fabricated via a sol-gel method assisted with solid-state route. In this composite, the Li 4 Ti 5 O 12 @C nanocrystals (T@C) are homogeneously dispersed into the two-dimensional sulfur-doped graphene. The introduced sulfur-doped graphene acted as conductive bridge within the resulted nanocomposite, thereby enhancing the electrical conductivity of T@C nanoparticles. The as-fabricated SG-T@C displays superior high-rate performance for lithium-ion batteries. It can deliver the capacities of 171.9 and 145.2 mAh/g at 0.1 and 10 C respectively. Besides, SG-T@C exhibits 96.2% capacity retention at 20 C over 800 cycles, demonstrating an excellent cycling stability. Therefore, the designed SG-T@C can be used as an advanced electrode for lithium-ion batteries. • Sulfur-doped graphene-improved Li 4 Ti 5 O 12 @C nanocomposite has been fabricated for the first time through a simple sol-gel method. • The constructed conductive networks by sulfur-doped graphene sheets and carbon film can greatly enhance the apparent electrical conductivity of Li 4 Ti 5 O 12 . • The fabricated anode displays superior rate capability for lithium-ion storage.

In Situ Fabrication of Porous Cox P Hierarchical Nanostructures on Carbon Fiber Cloth with Exceptional Performance for Sodium Storage.

Superior high-rate performance and ultralong cycling life have been constantly pursued for rechargeable sodium-ion batteries (SIBs). In this work, a facile strategy is employed to successfully synthesize porous Cox P hierarchical nanostructures supported on a flexible carbon fiber cloth (Cox P@CFC), constructing a robust architecture of ordered nanoarrays. Via such a unique design, porous and bare structures can thoroughly expose the electroactive surfaces to the electrolyte, which is favorable for ultrafast sodium-ion storage. In addition, the CFC provides an interconnected 3D conductive network to ensure firm electrical connection of the electrode materials. Besides the inherent flexibility of the CFC, the integration of the hierarchical structures of Cox P with the CFC, as well as the strong synergistic effect between them, effectively help to buffer the mechanical stress caused by repeated sodiation/desodiation, thereby guaranteeing the structural integrity of the overall electrode. Consequently, Cox P@CFC as an anode shows a record-high capacity of 279mAhg-1 at 5.0Ag-1 with almost no capacity attenuation after 9000 cycles.

Superior high-rate and cycle performances of a single-phase ferrous orthophosphate Na1.2Fe4(PO4)3 anode material for lithium-ion batteries

The development of low-cost and eco-friendly electrode materials is crucial for the next-generation rechargeable lithium-ion batteries (LIBs). Herein, the single-phase Na1.2Fe4(PO4)3 (NFP) with a monoclinic NaCo4(PO4)3-type structure is demonstrated to be a suitable anode material for LIBs. The NFP anode exhibits superior high-rate performance, releasing an initial charge capacity of 128.6 mAh g−1 at 10C and a high-capacity retention rate of 86.7% over 1500 cycles. The prominent rate performance and cycling stability of the NFP anode are attributed to the stable single-phase crystal structure and fast Li-ion diffusion verified by galvanostatic intermittent titration technique (GITT). Furthermore, the structure evolution and Li-ion diffusion pathway of the NFP anode are clarified by ex-situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and first-principles calculations.

NiCo‐Layered Double Hydroxide to Composite with Sulfur as Cathodes for High‐Performance Lithium‐Sulfur Batteries

AbstractLithium‐sulfur (Li−S) batteries have become a research focus for high‐energy‐density rechargeable batteries owing to the considerable theoretical energy density. However, the polysulfide shuttle and sluggish kinetics in lithium‐sulfur (Li−S) chemistry lead to low sulfur utilization, large polarization and rapid capacity decay, posing a fatal threat to the commercialization of Li−S batteries. Herein, we etched zeolitic imidazolate framework‐67 (ZIF‐67) with Ni2+ to manufacture NiCo‐LDH, which is used as a sulfur host material for lithium‐sulfur (Li−S) batteries. Benefited from the closely packed nano‐clusters and the hollow structure, the NiCo‐LDH could not only inhibit the lithium polysulfides (LiPSs) diffusion but also accelerate the redox reactions. Owing to these properties, the corresponding Li−S batteries exhibit a superior capacity (1540 mAh g−1 at 0.1 C) and high rate performance (485 mAh g−1 at 5.0 C). This work shows a promising way for layered double hydroxide as cathodes for Li−S batteries.

Improved High C-Rate Performance of LiFePO4 Battery Cathodes with Combined Polyaniline/Carbon Nanofiber Additive

Polyaniline (PANI), a conducting polymer, and carbon nanofibers (CNFs) were introduced as a combined additive to lithium ion battery cathodes. The PANI polymer is electrochemically active in the range of 2.0-3.8 V, which overlaps the operative redox couple of LiFePO4. The combined properties of PANI and CNF show that the composite material can act not only as a host material for improving Li+ ion intercalation but also as an agent for increasing overall battery conductivity. Electrochemical measurements showed that batteries fabricated with the combined LiFePO4/PANI/CNF cathode material had superior high-rate performance at >5C when compared against batteries made using either PANI or CNF as individual additives. The improvement can be attributed to an increase on the effect of, both, short-range and long-range conductivities.

Analysis and Design of Photovoltaic Nonlinear System: A Delta Operator Fuzzy Control Scheme

Aims: The paper is concerned with the problem of robust H∞ output feedback control for photovoltaic nonlinear system. Background: The PV systems are built to transform sun irradiance into electrical power. The dc-dc converters, such as buck type, boost type, and buck-boost type, have been widely implemented in the PV systems. Linear controllers for dc-dc converters are often designed based on mathematical models. To get a desired performance objective, an accurate model is essential. Objective: There has been increasing interest in the scheme of digital controller design for dc-dc converters. However, most of the research efforts are focused on the representation based on the standard forward-shift operator approach, which are of inherently ill-conditioned when datum are taken at high sampling rates. Compared with the forward-shift operator, the delta operator has many virtues which can be applied as a better representation of the underlying physical model under high sampling rates. Despite the delta operator possessing the superior high sample rate performance has been recognized in the past two decades, there exists little literature discussing the analysis and synthesis of photovoltaic nonlinear systems by using delta operator fuzzy control method, which motivates us to make an effort in this topic. Methods: We propose a Fuzzy Dynamic Output Feedback (FDOF) controller, and introduce a novel Lyapunov-Krasovskii Functional (LKF) in delta domain, the framework of robust H∞ output feedback control is investigated. Results: Sufficient conditions are derived for the existence of the desired FDOF controllers in terms of Linear-Matrix Inequalities (LMIs). A numerical example is used to illustrate the design procedure of the present method. Conclusion: This paper has studied the problems of robust H∞ output feedback control for photovoltaic nonlinear system with interval time-varying delay and parametric uncertainties. Based on the formulated fuzzy system and the FDOF controller, we introduced a Lyapunov-Krasovskii function in delta domain, the scheme of FDOF was proposed. Sufficient conditions for the existence of the FDOF controller were derived in terms of LMIs. A numerical example was used to demonstrate the effectiveness of our proposed methods.

A Novel Tin-Bonded Silicon Anode for Lithium-Ion Batteries.

Poor cyclic stability and low rate performance due to dramatic volume change and low intrinsic electronic conductivity are the two key issues needing to be urgently solved in silicon (Si)-based anodes for lithium-ion batteries. Herein, a novel tin (Sn)-bonded Si anode is proposed for the first time. Sn, which has a high electronic conductivity, is used to bond the Si-anode material and copper (Cu) current collector together using a hot-pressed method with a temperature slightly above the melting point of Sn. The cycling performance of the electrode is studied using a galvanostatic method. Nanoindentation and peeling tests are conducted to measure the mechanical strength of the electrodes. Direct current polarization and galvanostatic intermittent titration techniques are applied to assess the conductivity of the composites. Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy are conducted to evaluate the effect of the coating layer on the cycling ability of the composites. The Sn-bonded Si anodes show superior cycling stability and high rate performance with an improved initial Coulombic efficiency. Analyses reveal that the low-melting-point Sn helps to markedly improve the electronic conductivity of the electrodes and serves as a metallic binder as well to enhance the adhesive strength of the electrode. It is hopeful that this novel Sn-bonded Si anode provides a new insight for the development of advanced Si-based anodes for LIBs.

A high-voltage activated high-erformance cathode for aqueous Zn-ion batteries

Searching for high-capacity and stable cathodes is of paramount importance to the commercial development of high-energy-density, low-cost, and safe aqueous Zn-ion batteries (ZIBs). A technical challenge to this effort is the capacity-stability tradeoff encountered in all the oxide-based ZIB cathodes. Herein, we report a high-capacity and stable ZIB cathode enabled by in situ electrochemical oxidation of VO2 nanorods into bilayer V2O5•1.75H2O xerogel nano-grids at a high anodic potential (~1.55 V vs. Zn/Zn2+). VO2 is a better precursor than V2O3 to form V2O5•1.75H2O xerogel due to its high stability in aqueous solutions. The activated cathode exhibits a very high discharge capacity (610 mAh g−1 at 0.1 A g−1, a significant increase from 332 mAh g−1 of the pure VO2), superior high-rate performance (~410 mAh g−1 at 5 A g−1) and excellent cycling stability (~ 370 mAh g−1 at 5 A g−1 after 3000 cycles), which translates to an energy density/power density of 295 Wh kg−1/4,656 W kg−1 at 5 A g−1 and high round-trip efficiency of 85%. The activated VO2 is also found to possess low-crystallinity and nanowires morphology and exhibit a pronounced pseudocapacitive behavior and high ionic diffusion coefficient. Strong evidence has also been given to support simultaneous H+ and Zn2+ intercalation/extraction mechanisms in the activated VO2 and that the resultant excellent cycling performance is attributed to the high stability of V2O5•1.75H2O xerogel in the aqueous electrolytes and no formation of Zn3(OH)2V2O7•2H2O. Overall, the demonstrated electrochemically activated VO2 with both high capacity and stability is a promising cathode for practical ZIBs.