Batteries & Supercaps最新文献

Battery-type electrode materials with exceptionally high specific energy have been recognized as prospective materials for hybrid supercapacitor (HSC). In this study, a ternary NiMoO₄-rGO@V₂O₅ composite is synthesized for high performance HSC applications. The strategic integration of nickel molybdate (NiMoO₄), reduced graphene oxide (rGO), and vanadium pentoxide (V₂O₅) combines the fast-redox activity of NiMoO₄, the high electrical conductivity and surface area of rGO, and the excellent pseudocapacitive behavior of V₂O₅. The NiMoO₄-rGO@V₂O₅ composite obtains pore structure ranging from 20–30 nm with a higher specific surface area of 176.2 m²g⁻¹ and superior conductivity, demonstrating enhanced capabilities regarding the transfer of charge and diffusion of ions. Electrochemical measurements demonstrate that the NiMoO₄-rGO@V₂O₅ composite exhibits a high specific capacity of 361.5 mAh g⁻¹ at 1 A g⁻¹, excellent rate capability, and remarkable cyclic stability of 75% after 10,000 cycles. Furthermore, an HSC device assembled using the optimized composite as the positive electrode and activated carbon as the negative electrode and it delivered a capacitance of 207.5 F g⁻¹ at 2 mA cm⁻² with a specific energy of 73.77 Wh kg⁻¹ at a specific power of 640 W kg⁻¹. These outcomes underscore the potential of NiMoO₄-rGO@V₂O₅ composites as cutting-edge electrode materials for next-generation energy storage devices.

Supercapacitors are prized for their high-power delivery, though their energy storage capacity is generally lower than that of batteries. A novel one-pot strategy for synthesizing nitrogen-doped porous carbon derived from KOH and urea-activated wheat bread waste (Triticum aestivum) is presented. This unique synthesis simultaneously achieves chemical activation and nitrogen doping in a single-step process, offering a cost-effective and scalable route for high-performance electrode materials. The supercapacitive properties of bread waste-derived activated carbon (BWC-700) in a 1 M H₂SO₄ aqueous electrolyte are investigated, with 0.01 M hydroquinone (HQ) acting as a redox-active agent. Morphological analysis via field-emission scanning electron microscopy confirms the material's hierarchical porous structure. The (BWC-700) exhibits a specific capacitance of 486 F g⁻¹ at a current density of 1 A g⁻¹ in a half-cell configuration, with specific capacities of 1422 C g⁻¹ and 904 C g⁻¹ in three- and two-electrode systems, respectively. When HQ is incorporated into the electrolyte, the AC demonstrates excellent cyclic stability, retaining 82% of its capacitance after 5000 cycles. Notably, BWC-700 achieves a peak energy density of 56.5 Wh kg⁻¹, outperforming symmetric supercapacitors. These findings underscore the novel combination of waste valorization, green synthesis, and redox-enhanced energy storage, making this work highly relevant and competitive in the rapidly evolving field of supercapacitors.

The effect of an anion from the electrolyte salt plays a crucial role in modulating the solvation structure of the cation and the electrochemical performances of the energy storage systems. Herein, the effect of different anions such as chlorides (Cl⁻), nitrates (NO₃⁻), sulfates (SO₄²⁻), and their influence on the solvation structure, diffusivity of Zn²⁺ cation, redox kinetics, and ion storing behavior of Zn-based Prussian blue analogue (PBA) electrodes are explored. Combining molecular dynamics simulations and experimental observations, the results divulge that different anions can significantly modulate the solvation shell and diffusivity of the cation, thereby influencing the electrochemical properties of the PBA electrodes. Further, increased anion concentration and its consequences on the aforementioned properties are investigated by employing 6 m water-in-salt electrolyte (WiSE). It is found that in ZnCl₂, a moderate Zn²⁺-Cl⁻ interaction offers higher ion diffusivity, thereby facilitating more efficient Zn²⁺ intercalation into the PBA electrode, resulting highest specific capacity of 56 mAh g⁻¹ at 2C-rate and the highest coulombic efficiency of 80% in 1 m ZnCl₂ and shows superior cycling stability in long-term cycling in 6 m-WiSE comparison to other anions. This work highlights the pivotal role of anions in tuning electrolyte molecular structure and its dynamics, ultimately governing cation transport and electrode kinetics in aqueous zinc-ion batteries.

One of the challenges in the development of Mg batteries is the lack of Mg electrolytes with good compatibility with both the Mg metal anode and cathode materials. In recent years, Mg salts based on weakly coordinating anions have emerged as promising Mg electrolytes. In this work, we systematically investigate the effects of salt concentration on the physicochemical properties, salt–solvent interactions, and electrochemical performance of the Mg[Al(hfip)₄]₂/G2 electrolyte. Infrared (IR) and Raman spectroscopy are used to study the changes in the electrolyte speciation across different concentrations, indicating a decreased amount of free glyme solvent with higher salt concentration. Mg plating/stripping of selected electrolytes is evaluated through three different testing protocols (conventional cycling, macrocycling, and cycling with added open-circuit voltage (OCV) rests) and compatibility with different cathode materials such as Chevrel phase, sulfur, and various organic redox-active compounds. In the electrochemical tests, more concentrated electrolytes demonstrated improved cathode cycling efficiency and more stable Mg plating/stripping, making an argument for Mg electrolytes with higher salt concentration. However, higher salt concentrations can increase the cost of Mg electrolytes. Further Mg electrolyte optimization should focus on adjusting electrolyte composition to specific electrode materials and other cell components, while maintaining a reasonable cost.

The rising costs of cobalt and nickel, alongside mounting environmental concerns, have spurred intensive research into alternative battery chemistries that eliminate these critical elements. This shift aligns with the broader industry push toward low-cost, sustainable materials that can rival the performance of lithiumironphosphate (LFP) systems. In this context, the present work introduces a layered oxide cathode composition, NaFe_0.45Mn_0.5Ti_0.05O₂ (NFMTO), which delivers high specific capacity and enhanced cycling stability. The substitution of Ti⁴⁺ into the Fe/Mn lattice effectively modifies the transition metal–oxygen (TM-O) layer spacing, thereby improving structural stability during cycling. As a result, the NFMTO cathode exhibits an initial discharge capacity of 125 mAh g⁻¹ at 0.1C (2.0–4.2 V vs. Na⁺/Na) and retains 78.4% of its capacity after 50 cycles. Additionally, it delivers 118 mAh g⁻¹ with 70% capacity retention over 200 cycles in a voltage window of 2.0–4.0 V. The full-cell performance of NFMTO is evaluated in a pouch cell configuration using hard carbon as the anode, further demonstrating its practical viability. The assembled pouch cell delivered an initial discharge capacity of 103 mAh g⁻¹ at 0.05C (2.0–4.2 V) and retained 90% of its capacity after 10 cycles.

The agglomeration caused by high loading and the blockage of electrolyte ion transport are the main bottleneck problems that limit the application of layered double hydroxide (LDH) materials. Here, a hierarchically structured CuO@CoNi-LDH composite is constructed on a copper foam (CF) scaffold, with alkali/halogen dual-ion codoping employed to synergistically enhance its electrochemical performance. The CF/CuO core provides a conductive backbone for high-loading LDH, while Li⁺ optimizes the electronic structure. The Br⁻ ion with multiple effects can reduce the OH⁻ adsorption energy and strengthen the covalent characteristics of Co/Ni-O in the LDH, thereby improving reaction activity. The hierarchical architecture combined with the ionic size effect facilitates charge transport and ion diffusion, enabling the LDH_(Li,Br) electrode to deliver a high areal capacitance of 45.9 F cm⁻² at 5 mA cm⁻² and still retain 56% of its initial capacitance after 14 000 cycles under a high mass loading of 16 mg cm⁻². An asymmetric supercapacitor using CF/CuO@CoNi-LDH(LiBr)//AC exhibits excellent performance (1.87 F cm⁻² at 5 mA cm⁻², 55.6% retention at 30 mA cm⁻²), stable cycling (89.15% after 6400 cycles), and high energy density (0.67 mWh cm⁻²), highlighting the practical potential of dual-ion doping and hierarchical design.

The crystalline–amorphous heterojunction (C–AH) has become an important strategy for constructing electrode materials due to the synergistic effect between the high conductivity from the crystalline phase and the fast ion transport capabilities from the amorphous phase. In this work, a NiCoMo/Ag₁ (NCM/Ag₁) electrode material with abundant C–AH interfaces is successfully produced on nickel foam substrates through a facile one-step hydrothermal approach. The optimized NCM/Ag₁ electrode demonstrates good electrochemical performance, delivering an areal capacitance of 9266.7 mF cm⁻² (125.23 mAh g⁻¹) at 2 mA cm⁻² and retaining 84.7% rate capability at 10 mA cm⁻². It is combined with activated carbon to construct an asymmetric supercapacitor, which achieves an energy density of 55.13 Wh kg⁻¹ at a power density of 750 W kg⁻¹, while also demonstrating a capacity retention of 79.7% after 10 000 cycles. This research supplies a theoretical basis for the design of high-performance supercapacitors.

Silicon monoxide (SiO)-based materials have significant potential as high-capacity anode materials for lithium-ion batteries (LIBs). However, the low initial Coulombic efficiency (ICE) associated with the irreversible electrochemical reaction of the amorphous SiO₂ phase (a-SiO₂) in SiO hinders its application in commercial LIBs. The preemptive phase transition of a-SiO₂ to an inactive silicate phase using a metal hydride is a promising strategy for improving the ICE. However, this process inevitably leads to reversible capacity loss. In this study, a high-capacity Si-rich SiO_x composite prepared by high-energy mechanical milling is premagnesiated using MgH₂, resulting in a significantly improved capacity and ICE compared to those of pristine SiO and Si-rich SiO_x composites. The resulting Si/Mg₂SiO₄ composite electrode exhibited a high initial discharge capacity of 1961 mAh g⁻¹ with a high ICE of 87.0% and maintained highly stable capacity retention after 200 cycles compared to the Si-rich SiO_x. These improved electrochemical properties are attributed to the preemptively synthesized Mg₂SiO₄, which not only prevents irreversible reactions between lithium and a-SiO₂ during the initial lithiation but also acts as a buffer phase that effectively reduces volume expansion during cycling.

Aqueous Zn–S batteries (AZSBs) have emerged as a next-generation energy storage system, offering high energy density, cost-effectiveness, and enhanced safety. However, their widespread adoption is restricted by multiple challenges, including sluggish sulfur redox kinetics that lead to high polarization voltage and poor capacity retention of the sulfur cathode. Moreover, unwanted reactions and irregular zinc dendrite development on the anode severely compromise electrochemical performance, particularly in capacity retention and cycle life. Among the various strategies, electrolyte engineering has emerged as an effective approach to overcoming these bottlenecks by regulating sulfur conversion, stabilizing zinc plating/stripping, and expanding the electrochemical stability window. This review offers an in-depth exploration of recent innovations in electrolyte design for AZSBs, comprising discussions on the fundamental sulfur redox reaction mechanism, the challenges faced by AZSBs at both the cathode and anode, and the systematic strategies for enhancing battery performance through electrolyte modification. Finally, future research directions are proposed to optimize electrolyte formulations for achieving high-performance and long-lasting AZSBs, paving the way for their commercial viability.

Zeolitic-imidazolate frameworks (ZIFs) are gaining widespread attention in energy storage research owing to their high porosity, structure tailorability, and multiple reaction sites. However, their very low inherent electrical conductivity limits their pristine usage in supercapacitors. Therefore, a promising way is to integrate ZIFs with suitable conductive materials, which can help to provide additional conductive pathways, thereby promoting fast charge transfer. In this work, a strategy is proposed to improve the conductivity of ZIF-8 by incorporating it with PANI-PPy conducting copolymer-derived carbon (CoP@C). The prepared ZIF-8/CoP@C composite possesses nitrogen units (pyridinic-N, graphitic-N, and pyrrolic-N) that enhance its electronic conductivity and provide additional pseudo-capacitance. In a three-electrode setup with 1 M H₂SO₄ electrolyte, the ZIF-8/CoP@C composite electrode demonstrated the highest specific capacitance of 247.9 F g⁻¹, which is much higher than the pristine ZIF-8 electrode (72.1 F g⁻¹) at 1 A g⁻¹. Furthermore, the ZIF-8/CoP@C electrodes were employed to construct an aqueous symmetrical supercapacitor that delivers a high energy density of 25.7 Wh kg⁻¹ and a power density of 402.1 W kg⁻¹, along with prolonged cyclic stability of 92.9% after 10 000 charge–discharge cycles. This study introduces a benchmark for employing conducting copolymers to elevate the electrochemical performance of different ZIFs/MOFs in supercapacitors.