Ultrahigh Cycling Stability Research Articles

Modulating the electron spin states of Na2FePO4F cathode via high entropy strategy for enhanced sodium storage and ultra-high cycling stability

Modulating the electron spin states of Na2FePO4F cathode via high entropy strategy for enhanced sodium storage and ultra-high cycling stability

Dually encapsulated LiMn0.6Fe0.4PO4 architecture with MXenes and amorphous carbon to achieve high-performance and ultra-stable lithium batteries

An LMFP@MXene@C cathode material was fabricated by electrostatic adsorption and in situ graphitization, providing optimized Li+ transmission and a stable structure featuring ultrahigh average capacity and cycle stability.

Transformation of vulnerable imine bond into aromatic in 3D COF for ultrastable lithium-ion batteries

About half of the thus far reported covalent organic frameworks (COFs) are of imine-linked 2D and 3D structures, which usually suffer from relatively low working stability due to the vulnerable easily nucleophile-attacked C=N bond nature. Herein, an imine-linked 3D COF, TAM-DMPZD-COF, was constructed by reaction between 4-connected Td 4,4′,4′',4′''-methanetetrayltetraaniline and 2-connected 5,10-methyl-5,10-dihydrophenazine-2,7-dicarbaldehyde. Addition of S8 into the above mentioned reaction leads to the transformation of imine bond into an aromatic thiazole moiety in the framework, affording the thiazole-linked 3D COF, TAM-DMPZD-COF-S. This result in significant enhancement over the ultrahigh cycling stability of the TAM-DMPZD-COF-S-based LIBs cathode, with the thus far reported highest 50000 cycles and 0.00016% capacity decay per cycle at 10 A g-1, in good contrast to only 55% capacity retention after 5000 cycles at 10 A g-1 for TAM-DMPZD-COF-based LIBs cathode. Nevertheless, transformation of imine bond into an aromatic thiazole moiety in the 3D framework also induces an increase in the redox active sites for both Li+ and PF6- ions, resulting in enhanced ion storage capacity and energy density of TAM-DMPZD-COF-S (325 mA h g-1 and 736 W h kg−1 at 0.1 A g-1), surpassing those for traditional inorganic cathodes and all the thus far reported COFs-based electrodes.

Unraveling the Function Mechanism of N-Doped Carbon-Encapsulated Na3V2(PO4)3 Cathode toward High-Performance Sodium-Ion Battery with Ultrahigh Cycling Stability.

The NASICON-type Na3V2(PO4)3 (NVP) is recognized as a potential cathode material for Na-ion batteries (SIBs). Nevertheless, its inherent small electronic conductivity induces limited cycling stability and rate performance. Carbon coating, particularly N-doped carbon, has been identified as an effective strategy to address these challenges. Hence, N-doped carbon-coated NVP was successfully produced by a straightforward high-temperature solid-phase method, and the mechanism of N-doped carbon coating in regulating the electrochemical kinetics of NVP was unraveled. The N-doped carbon layer establishes a robust conductive network that interconnects the active particles, facilitating electron transfer within the electrode. SEM images after cycling show that the uniform carbon coating mitigated NVP agglomeration, thereby reducing undesired side reactions between electrode and electrolyte. The discharge capacities of NVP/N-C2 electrodes at 0.1, 0.2, 0.5, 1, 2, 5, and 10C reach 116.0, 114.6, 112.6, 111, 108.7, 104.2, and 99.4 mAh g-1, respectively. Even at 20C, the discharge capacity remains up to 92.2 mAh g-1, which is approximately 80% of the discharge capacity at 0.1C. When the rate returns to 0.1C, the NVP/N-C2 cathode still exhibits a discharge capacity of 115.9 mAh g-1, showing excellent electrochemical reversibility. This study presents a viable approach for fabricating NVP with a N-doped carbon coating, showcasing enhanced sodium storage properties.

High Performance and Durable Electrochromic Device of Fe(II)-Based Metallo-Supramolecular Polymer for Smart Electrochromic Window Application

A durable semi-solid-state electrochromic device (ECD) of Fe(II)-based metallo-supramolecular polymer (polyFe) was fabricated by incorporating Nickel hexacyanoferrate (NiHCF) as a charge-balancing layer. The ECD exhibited reversible blue-violet to bleached optical transition in a very low potential window of +1.2V to +0.2V. The low operating potential window enabled ultra-high cycle stability and improved optical memory of the ECD. For the further improvement of the EC properties, it was revealed that the optimization of the film thickness of the polyFe and NiHCF is critical to maintaining the charge balance between the working and counter electrodes. At last, the cyclic stability for the repeated color changes over 100,000 cycles were achieved. This finding will help engineers and scientists to fabricate a low-voltage-driven, long-lasting ECD for real-life application in smart electrochromic window technology.

Sodium‐Difluoro(oxalato)Borate‐Based Electrolytes for Long‐Term Cycle Life and Enhanced Low‐Temperature Sodium‐Ion Batteries

AbstractSodium‐ion batteries (SIBs) are emerging as a promising alternative for next‐generation energy storage solutions, driven by the economic and environmental benefits of abundant sodium resources. A pivotal aspect of SIB advancement is the development of advanced electrolytes, which remains a formidable challenge. Herein, a facile and scalable synthesis method for low‐cost sodium‐difluoro(oxalato)borate (NaDFOB) is reported and explored its application as a standalone electrolyte salt for SIBs. The NaDFOB‐based ether electrolyte demonstrates exceptional electrochemical stability, solvent compatibility, and the unique capacity to form a dense, robust solid‐electrolyte interphase layer on electrode surfaces. As a result, the Na4Fe3(PO4)2P2O7 (NFPP) cathode with NaDFOB‐based electrolyte exhibits ultrahigh cycling stability with a remarkable capacity retention of 98.7% after 1000 cycles. Furthermore, an Ah‐level hard carbon (HC)//NFPP pouch cell using NaDFOB‐based ether electrolyte shows an impressive cycle life of 500 cycles, coupled with an average Coulombic efficiency of 99.9%. The pouch cells also maintain superior electrochemical performance across a broad temperature range from −40 to 60 °C, showcasing the electrolyte's versatility. This work contributes significant insights into the strategic design and application of innovative salts, paving the way for longer‐lasting SIBs with enhanced electrochemical performance.

A novel embedded KVO3/NC anode for high-performance lithium-ion batteries

Vanadium-based metallic salts, characterized by their intrinsic low electronic conductivity, are impeding their advancement as anode materials in the realm of lithium-ion battery technology. This study presents a novel embedded anode material KVO3/NC (KVO/NC) synthesized via a sol–gel method, with KVO3 (KVO) particles in situ growing on N-doped carbon, thereby ameliorating conductivity and electrochemical performance. The findings reveal that KVO/NC composite has three lithium-ion storage sites, ultra-high cycling stability (289 mA h/g@5000 cycles@10 C@100 %), and superior rate performance (249 mA h/g@15 C; 221 mA h/g@20 C). Coupled with LiFePO4 cathode, it achieves a competitive energy density (391 W h kg−1@0.1 C; 1–3.9 V). This work reveals the practical potential of KVO/NC as a new type of lithium-ion battery anode material with high energy density and long cycle life through a series of ex situ/in situ characterizations.

Concurrently boosted oxygen reduction/evolution electrocatalysis over highly loaded CoNi/onion-like carbon hybrid nanosheets

Balancing the bicatalytic activities and stabilities between oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a critical yet challenging task for exploring advanced rechargeable Zinc–air batteries (ZABs). Herein, a hybrid nanosheet catalyst with highly dispersed and densified metallic species is developed to boost the kinetics and stabilities of both ORR and OER concurrently. Through a progressive coordination and pyrolysis approach, we directly prepared highly conductive onion-like carbon (OLC) accommodating dense ORR-active CoNC species and enveloping high-loading OER-active CoNi-synergic structures within a porous lamellar architecture. The resultant CoNi/OLC nanosheet catalyst delivers better ORR and OER activities showcasing a smaller reversible oxygen electrode index (ΔE = Ej10 − E1/2) of 0.71 V, compared to state-of-the-art Pt/C-RuO2 catalysts (0.75 V), Co/amorphous carbon polyhedrons (0.80 V), NiO nanoparticles with higher Ni loading (1.00 V), and most CoNi-based bifunctional catalysts reported so far. The rechargeable ZAB assembled with the developed catalyst achieves a remarkable peak power density of 270.3 mW cm−2 (172 % of that achieved by Pt/C + RuO2) and ultrahigh cycling stability with a negligible increase in voltage gap after 800 h (110 mV increase after 200 h for a Pt/C + RuO2-based battery), standing the top level of those ever reported.

Mastering Surface Sulfidation of MnP-MnO2 Heterostructure to Facilitate Efficient Polysulfide Conversion in Li─S Batteries.

The development of lithium-sulfur (Li─S) batteries has been hampered by the shuttling effect of lithium polysulfides (LiPSs). An effective method to address this issue is to use an electrocatalyst to accelerate the catalytic conversion of LiPSs. In this study, heterogeneous MnP-MnO2 nanoparticles are uniformly synthesized and embedded in porous carbon (MnP-MnO2/C) as core catalysts to improve the reaction kinetics of LiPSs. In situ characterization and density functional theory (DFT) calculations confirm that the MnP-MnO2 heterostructure undergo surface sulfidation during the charge/discharge process, forming the MnS2 phase. Surface sulfidation of the MnP-MnO2 heterostructure catalyst significantly accelerated the SRR and Li2S activation, effectively inhibiting the LiPSs shuttling effect. Consequently, the MnP-MnO2/C@S cathode achieves outstanding rate performance (10C, 500mAhg-1) and ultrahigh cycling stability (0.017% decay rate per cycle for 2000 cycles at 5C). A pouch cell with MnP-MnO2/C@S cathode delivers a high energy density of 429Whkg-1. This study may provide a new approach to investigating the surface sulfidation of electrocatalysts, which is valuable for advancing high-energy-density Li-S batteries.

Rational Construction of Bi2CuO12Se4 and VGCFs@Fe2O3 Composite Electrodes for High-Performance Semi-Solid-State Asymmetric Supercapacitors.

Recently, supercapacitors (SCs) are extensively explored as effective energy storage devices. Specifically, asymmetric SCs are being developed to enhance energy density using suitable materials with favorable nanostructures. This study describes the construction of a bismuth copper selenite (BCS-200) working electrode with an ultrathin nanosheet(UTNS) architecture. This morphology is achieved using a low-cost electrodeposition (ED) method, followed by annealing. The impact of ED time on the development of morphology is studied by synthesizing comparative electrodes simultaneously. The optimized BCS-200 electrode prepared with a deposition time of 200 s shows higher specific capacity/capacitance (Cs/Csc) values of 330.9 mAh g-1/2206.6 F g-1 than the other synthesized electrodes (BCS-100, BCS-150, BCS-250, and BCS-300). Besides, a vapor-grown carbon fiber (VGCF)-added Fe2O3 composite coated on nickel foam (NF) is developed as a negative electrode. The VGCFs@Fe2O3/NF electrode exhibits the (Cs/Csc) values of 183.5 mAh g-1/734.4 F g-1, which is associated with ultra-high cycling stability. In addition, the fabricated BCS-200 and VGCFs@Fe2O3/NF electrodes are combined to construct a wearable semi-solid-state asymmetric SC (SSASC) with an energy density (Ed) of 20.5Wh kg-1 and a cycling stability of 91.7% over 40000 charge/discharge cycles. Furthermore, the real-time applicability of the SSASC is verified by powering it in practical applications.

Electropolymerization of a Carbonyl-Modified Dihydropyrazine Derivative for Aqueous Zinc Batteries with Ultrahigh Cycling Stability.

The design of aqueous zinc-ion batteries (ZIBs) that have high specific capacity and long-term stability is essential for future large-scale energy storage systems. Cathode materials with extended π-conjugation and abundant active sites are desirable to enhance the charge storage performance and the cycling stability of the aqueous ZIB. Based on this concept, 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetrone was chosen as the monomer to be electropolymerized onto carbon cloth (PDHPQ-Tetrone/CC). When used as the cathode material for aqueous ZIBs, an exceptional cycling life (>20,000 cycles) at a current density of 10 A g-1 was achieved, with the specific capacity maintained at 82.8% and with the Coulombic efficiency at around 100% throughout cycling. At the charge-discharge current density of 0.1 A g-1, the ZIB with PDHPQ-Tetrone/CC achieved a high specific capacity of 248 mAh g-1. Kinetic analyses showed that both surface-capacitive-controlled processes and semi-infinite diffusion-controlled processes contribute to the stored charge. The charge storage mechanism was investigated with ex situ characterizations and involves the redox processes of carbonyl/hydroxyl and amino/imino groups coupled with insertion and extraction of both Zn2+ and H+.

Mo-based compounds coating to stabilize Mn-based layered oxide cathode material towards high-performance Na-ion batteries with ultrahigh cycling stability

Layered oxide cathode materials have good structural stability and high capacity, making them ideal cathode materials of Na-ion batteries (SIBs). Nonetheless, the irreversible phase transitions and metal dissolution often result in poor cycling stability. Here, a simple strategy was developed to Na2MoO4 and MoO3 coated Na0.67Fe0.15Cu0.1Mn0.65Ni0.1O2 (NFCMN-M) as cathode material of SIBs with ultrahigh cycling stability caused by the enhanced kinetic. The formed Na2MoO4 layer on the surface of Na0.67Fe0.15Cu0.1Mn0.65Ni0.1O2 (NFCMN) particles supplies a good conductive connection, and inhibits side effects between cathode material and electrolyte. Thanks to the unique component, the as-prepared NFCMN-M shows a good rate performance with a reversible discharge capacity of 132.4, 112.6, 102.3, 87.1 and 79.3 mAh g−1 at 0.1, 0.5, 1, 3 and 5C, respectively. The NFCMN-M also delivers an initial capacity of 73.7 mAh g−1 at 10C and an ultrahigh cycling stability with a capacity retention rate of about 80 % after 1000 cycles. The result confirms that the Na2MoO4 modification is a direct and effective strategy to improve the capacity and enhance cycling stability of NFCMN at high charge-discharge rates.

Inhibiting the phase transition of WO3 for highly stable aqueous electrochromic battery

Aqueous electrochromic battery (ECB) has shown intense potential for achieving energy storage and saving simultaneously. While tungsten oxide (WO3) is the most promising EC material for commercialization, the cycling stability of WO3-based aqueous ECBs is currently unsatisfactory due to the repeated phase transition during the redox process and the corrosion by acidic electrolytes. Herein, we present a titanium-tungsten oxide alloy (Ti-WO3) with controllable morphology and crystal phase synthesized by a facile hot injection method to overcome the challenges. In contrast to conventional monoclinic WO3, the Ti-WO3 nanorods can stably maintain their cubic crystal phase during the redox reaction in an acidic electrolyte, thus leading to dramatically enhanced response speed and cycling stability. Specifically, when working in a well-matched hybrid Al3+/Zn2+ aqueous electrolyte, our phase-transition-free cubic Ti-WO3 exhibits an ultra-high cycling stability (>20000 cycles), fast response speed (3.95 s/4.65 s for bleaching/coloring), as well as excellent discharge areal capacity of 214.5 mA h m−2. We further fabricate a fully complementary aqueous electrochromic device, for the first time, using a Ti-WO3/Prussian blue device architecture. Remarkably, the complementary ECB shows >10000 stable operation cycles, attesting to the feasibility of our Ti-WO3 for practical applications. Our work validates the significance of inhibiting the phase transitions of WO3 during the electrochromic process for realizing highly cyclable aqueous ECB, which can possibly provide a generalized design guidance for other high-quality metallic oxides for electrochemical applications.

Aqueous hybrid iron-ion battery capacitors with ultra-long cycle life

With the over-exploitation of lithium resources, there is a tendency to find a new metal-ion energy storage device to replace lithium-ion batteries. In recent years, Fe-ion energy storage devices are acknowledged for their low cost, abundant resources, and safe characteristics, but their full potential has yet to be widely explored. Herein, we propose a new hybrid iron-ion battery capacitor (H-IIBC) energy storage device. The H-IIBC device prepared with nano flower-like activated carbon (FAC) as the cathode material, high-purity iron sheet as the anode material, and 1 M FeSO4 + NH4Cl aqueous solution as the electrolyte. After atomic molecular dynamics simulations and ex situ characterization analysis, ion adsorption/desorption occurs on the surface of the FAC cathode during the charging/discharging process, accompanied by the redox of iron ions. The stripping/deposition of iron occurs at the high-purity iron anode. With the charging/discharging process, the reaction at the anode favors the interconversion between Fe2+ and Fe3+ which requires less energy, thus ensuring that the high purity iron will not be depleted. Thus, the specific capacitance of prepared H-IIBC could reach 644 mF g−1 (399 mF cm−2) at a current density of 1 mA cm−2 in the voltage window of 0–1 V and shows ultra-high cycling stability at 3,000 cycles test. This economical, long-life and safe H-IIBC is expected to realize great potential in the field of energy storage in the near future.

In Situ Spontaneous Construction of Zinc Phosphate Coating Layer Toward Highly Reversible Zinc Metal Anodes.

Aqueous zinc ion batteries have received widespread attention due to their merits of high safety, high theoretical specific capacity, low cost, and environmental benignity. Nevertheless, the irreversible issues of Zn anode deriving from side reactions and dendrite growth have hindered its commercialization in large-scale energy storage systems. Herein, a zinc phosphate tetrahydrate (Zn3(PO4)2·4H2O, ZnPO) coating layer is in situ formed on the bare Zn by spontaneous redox reactions at room temperature to tackle the above issues. Particularly, the dense and brick-like ZnPO layer can effectively separate the anode surface from the aqueous electrolyte, thus suppressing the serious side reactions. Moreover, the ZnPO layer with high ionic conductivity, high Zn2+ transference number, and low nucleation barrier permits rapid Zn2+ transport and enables uniform Zn deposition, ensuring dendrite-free Zn deposition. As a result, the ZnPO@Zn symmetric battery achieves a high Coulombic efficiency of 99.8% and displays ultrahigh cycle stability over 6000h (> 8 months), far surpassing its counterparts. Furthermore, the ZnPO@Zn||MnO2 full battery exhibits excellent electrochemical performances. Therefore, this work provides a new reference for simple and large-scale preparation of highly reversible Zn metal anodes, and has great potential for practical applications.

Intercalation chemistry engineering strategy enabled high mass loading and ultrastable electrodes for High-Performance aqueous electrochemical energy storage devices

Aqueous electrochemical energy storage devices (AEESDs) are considered one of the most promising candidates for large-scale energy storage infrastructure due to their high affordability and safety. Developing electrodes with the merits of high energy density and long lifespan remains a challenging issue toward the practical application of AEESDs. Research attempts at electrode materials, nanostructure configuration, and electronic engineering show the limitations due to the inherent contradictions associated with thicker electrodes and ion-accessible kinetics. Herein, we propose an intercalation chemistry engineering strategy to enhance the electrolyte ion (de)intercalation behaviors during the electrochemical charge–discharge. To validate this strategy, the prototypical model of a high-mass-loading MnO2-based electrode is used with controlled intercalation of Na+ and H2O. Theoretical and experimental results reveal that an optimal content of Na+ and H2O on the MnO2-based electrode exhibits superior electrochemical performance. Typically, the resultant electrode exhibits an impressive areal capacitance of 1551 mF/cm2 with a mass loading of 9.7 mg/cm2 (at 1 mA/cm2). Furthermore, the assembled full-cell with obtained MnO2-based electrode delivers a high energy density of 0.12 mWh/cm2 (at 20.02 mW/cm2) and ultra-high cycling stability with a capacitance retention percentage of 89.63 % (345 mF/cm2) even after 100,000 cycles (tested over 72 days).

Ultrahigh cycling stability and wide infrared modulation of electrochromic devices based on electrodeposited triphenylamine cross-linked polyaniline derivatives

A flexible C-RECD based on a CPANI electrode is successfully fabricated, exhibiting wide-band electrochromic performance for visible-light color changes and infrared emissivity modulations, with ultrahigh cycling stability for 10 000 cycles.

Gate bias modulation towards organic electrochemical transistors with ultra-high cycling stability

The combination of appropriate gate bias and innovative structure design can significantly enhance the cycling stability of organic electrochemical transistors, which is crucial for controllable and extended lifetime of functional bioelectronics.

Construction of activated-CNT/carbon composite aerogel for supercapacitor electrode with ultra high cycle stability

Double layer supercapacitors are widely used for energy storage devices due to their excellent characteristics such as high stability and good cycling performance. In this work, a novel carbon aerogel doped with activated short multi-walled carbon nanotube (CA/AMWCNT composite aerogel) was constructed by sol-gel and carbonization process. The effects of the activated short multi-walled carbon nanotube (AMWCNT) addition amount on the microstructure and electrochemical properties of the composite aerogels were investigated. The composite aerogels with appropriate AMWCNT addition amount exhibited improved specific surface area, pore diameter and pore volume. In particular, the composite aerogel CA/AMWCNT-2.5, with higher specific surface area (640 m2 g−1) and pore volume (1.985 cm3 g−1), exhibited improved electrochemical performance with the equivalent series resistance and specific capacitance at a current density of 1 A g−1 being 0.36 Ω and 115.11 F g−1, respectively. Moreover, the composite aerogel CA/AMWCNT-2.5 electrode showed excellent cycle stability, with the retention rate maintaining 99.9 % even after 10,000 cycles, and three prepared symmetrical supercapacitors could supply power for a light emitting diode bulb for a long time. This work provides a new strategy for developing electric double layer supercapacitors with ultra high cycling stability, and the obtained CA/AMWCNT composite aerogels will have promising applications in the field of energy storage devices that require a long service lifetime.

In-situ fabricated porous Ni-Co-Mo based nanosheet array electrodes for hybrid supercapacitors with long-cycle stability

The porous NiCoMo-based ternary nanosheet arrays have been synthesized on carbon cloth (CC) substrate by a simple hydrothermal process combined with electrochemical assisted template etching method. CC@ZnO@NiCoMo composite exhibits charge/discharge activation phenomenon and holds a capacitance of 8.84 F cm−2 after 3000 cycles at 8 mA cm−2. The porous electrode structure formed by etching ZnO template not only makes it easier for the electrolyte to permeate and exposes the active point as much as possible, but also reduces the charge transfer impedance from 1.32 to 0.92 Ω. As expected, Asymmetric supercapacitors assembly with CC@ZnO@NiCoMo composite achieves a high energy density of 0.64 mWh cm−2 at 3.2 mW cm−2 and ultra-high cycle stability of 181 % after 10,000 cycles. The excellent electrochemical properties of the electrode material is mainly attributed to the synergistic effect between the multi-components of the nanosheets and the enrichment of Zn2+ formed by template etching in the solution, which helps to maintain the relatively stable morphology of Ni-Co-Mo based nanosheets.