Batteries & Supercaps最新文献

The increment in the energy demand and the limited availability of materials for manufacturing large-scale energy storage batteries based on Li-ion chemistry has increased the study of alternative technologies, including Na-ion batteries. The quest for superior electrochemical performances has led to the development new cathodes, such as Prussian blue and its analogs. Among the different members of this family of materials, KNi[Fe(CN)₆] has attracted great attraction because of its low synthesis cost and excellent stability. Multiple synthesis approaches based on coprecipitation methods have been explored to optimize its capacity to intercalate sodium; however, the effects of the synthesis conditions on the structural and electrochemical properties of KNi[Fe(CN)₆] remain vague. Therefore, in this work, we propose a detailed analysis of how the main synthesis parameters define the structural and electrochemical properties of KNi[Fe(CN)₆].

High-voltage spinel LiNi_0.5Mn_1.5O₄ (LNMO) has been highlighted as one of the most promising cathode materials for next-generation Li-ion batteries. However, its performance is known to have shortcomings, i. e., voltage hysteresis induced by the increasing impedance of LNMO during electrochemical cycling at high voltage operation. This paper demonstrates an innovative design of LNMO cathode materials to alleviate voltage hysteresis by combining unique characteristics of truncated octahedral LNMO with 2D exfoliated graphene (EG). The exposed (100) plane of truncated LNMO particles is known to have superior Li⁺ ion conduction. Meanwhile, the (111) plane is known to have excellent resistance to metal dissolution. Moreover, it was revealed that the presence of the EG framework as an interconnection aide could significantly improve the charge transfer process, helping to alleviate the voltage polarization. The sample with optimum LNMO-EG composition shows a stable electrochemical performance with a capacity retention of 86.56 % after 300 cycles of charge-discharge measurement at 1 C while exhibiting almost 3 times lower voltage hysteresis (0.233 mV/cycle) compared to the pristine LNMO (0.678 mV/cycle). This result demonstrates that combining the uniqueness of truncated LNMO and 2D EG can be a promising strategy to improve the electrochemical performance of LNMO cathode materials for next-generation batteries.

MXene and TMDs are two of the emerging electrode materials for supercapacitors owing to their unique physicochemical properties such as high conductivity, large surface area, and rich redox active sites. However, sheet restacking, volume expansion and oxidation hinder these materials from being used in practical applications. In this work, a 3D ternary hybrid structure of metallic VSe₂, Ti₃C₂T_x MXene and carbon nanotube was designed to address some of the challenges in 2D materials-based electrodes for supercapacitor application. The exfoliated MXene and CNT decorated VSe₂ 3D structure showed excellent synergy between each component to deliver promising energy storage and cycling performance. The ternary hybrid structure also can suppress the surface oxidation of MXene sheets during the hydrothermal reaction. Furthermore, an asymmetric supercapacitor fabricated with VSe₂/e-MXene/CNT and MoS₂/MXene delivered the highest energy density of 35.91 Wh/kg at a power density of 1280 W/kg and a remarkable cycle life.

The rise of electronic societies is driving a surge in the demand for energy storage solutions, particularly in the realm of renewable energy technologies like batteries, which rely heavily on efficient electrode materials and separators. As an answer to this necessity, Covalent Organic Frameworks (COFs) are emerging and a highly intriguing class of materials, garnering increased attention in recent years for their extensive properties and possible applications. This review addresses the remarkable versatility and boundless potential of COFs in scientific fields, mainly focusing on multivalent metal ion batteries (MMIBs), which include AIB (Aluminium-ion batteries), MIB (Magnesium-ion battery), CIB (Calcium-ion battery), and ZIB (Zinc-ion battery), as both electrode materials and separators across a spectrum of battery technology. Inclusive of their approaches, merits, and reaction mechanisms, this review offers an extensive summary of COFs concerning multivalent ion batteries. By providing a rigorous analysis of COF attributes, electrochemical behaviour, and methodologies, our explanation contributes to a deeper understanding of their potential in advancing battery technology.

All-solid-state batteries have attracted much attention because of the expected high energy density and inherent safety stemming from their nonflammable property. While improving the energy density of the cathode poses a significant challenge, here we introduce a novel battery design strategy to enhance energy density by employing bifunctional cathode material, allowing the weight ratio of the active material to be increased without using an electrolyte for the cathode. By employing lithium-containing vanadium halide Li₂VCl_4, serving as both active material and electrolyte, the all-solid-state battery cell with no electrolyte for the cathode with a capacity approaching the theoretical limit is demonstrated. In addition, we present a guideline for improving capacity retention from the perspective of interfacial stability. Notably, thermodynamic analysis revealed interfacial instability between Li₂VCl₄ and sulfide material. A double-layer separator, incorporating halide materials for the cathode side, was implemented to enhance the interfacial stability and mitigate the capacity degradation. Furthermore, it was found that the rate capability depends on the lithium content in synthesized Li_2-xVCl₄ and does not change with the state of charge significantly. This study will contribute to designing the bifunctional cathode material for an all-solid-state battery and describe its unique properties.

1,3-Dioxolane (DOL) can undergo in-situ polymerization in batteries to form solid-state organic electrolyte PDOL. When applied to NCM811||Li battery system, PDOL electrolyte helps optimize the contact and interface stability between electrolyte and electrodes. This study explores the effects of PDOL with PE separators coated with Li1_.3Al_0.3Ti_1.7(PO₄)₃(LATP) on the performance of NCM811||Li batteries. 2,2,2-trifluoroethyl phosphite (DETFPi), was mixed with DOL at a 1 : 35 mass ratio. Then, LiBF₄ was used to initiate in-situ polymerization and thereby obtained DETFPi-PDOL electrolyte after 24 h at room temperature. The composite electrolyte exhibits enhanced ion conductivity (1.59×10⁻⁴ S cm⁻¹), high lithium ion transference number (0.78), wide electrochemical stability window (4.53 V), and high critical current density (2.2 mA cm⁻²). Li||PDOL@LATP||Li battery shows extremely low overpotential (35 mV) after a constant current stable cycle of 500 h at 1.0 mA cm⁻². After 500 cycles at 1 C, the remaining capacity is 153.9 mAh g⁻¹ with a capacity retention of 82.1 % in NCM811||PDOL@LATP||Li batteries. This indicates that the LATP coating on the surface of the PE separator plays an important role in optimizing the performance of DETFPI-PDOL electrolyte batteries. LATP and DETFPI-PDOL are effective in improving the cycling stability, rate performance, and interface state of NCM811 batteries.

As demand for micro-power sources grows, micro-supercapacitors (MSCs) have become critical for miniaturized devices, offering robust electrochemical energy storage. However, the challenge remains to develop a simple, scalable fabrication method that achieves both high energy and power densities. In this study, we present a refined approach to fabricating MSCs with 3D interconnected graphene/carbon nanotube (CNT) composite electrodes. Our method combines flash lamp annealing (FLA) and laser ablation, where FLA converts graphene oxide (GO) and CNT composite films into 3D-structured graphene/CNT electrodes, and laser ablation precisely patterns them into interdigitated designs. This dual-process technique produces MSCs with exceptional electrochemical performance, including an impressive areal capacitance of 26.11 mF/cm² and a volumetric capacitance of 31.88 F/cm³. These devices also achieve energy densities of 3.72 μWh/cm² and 4.43 mWh/cm³, maintaining 97 % of their initial capacitance under extreme bending, demonstrating outstanding mechanical flexibility and durability. Furthermore, the scalability of this method was validated by configuring MSCs in series and parallel, achieving enhanced voltage and current outputs without additional interconnections. Overall, the integration of FLA and laser ablation holds significant promise for advancing the performance and scalability of micro-sized energy storage devices, addressing the growing need for efficient, flexible, and high-capacity micro-power sources.

In this work, Density Functional Theory (DFT) is used to study pristine and defective GDY. We investigate the effect of Li atom adsorption on the electronic and structural properties of this 2D material. In both cases, the Li atom is located at the corner of the triangular-like pore (H1), but with a slight shift for the defective system. In the perfect system, the Li−C bond distances range from 2.289 Å to 2.461 Å, while in the defective case, they range from 2.237 Å to 3.184 Å. In the perfect case, the GDY−Li system becomes metallic and the Li 2 s states are stabilized. Charge transfer to the surfaces occurs near the vicinity of the Li atom. The C vacancy generates new C=C bonds similar to double bonds, enhancing the interaction with Li through strong conjugation. After Li adsorption, the sum of bond order for all the C atoms increases in both structures, from 0.4 % to 6 %. The Li storage capacity without significant restructuring is six Li atoms. When the atom concentration increases, the OCV values for Li decrease from 0.93 V to 0.23 V. For defective GDY, the specific capacity is 788 mAhg₋₁, which is slightly higher than for pristine case.

The metal-ion battery manufacturing growth rates increase attention to the safety issues. For promising sodium-ion batteries, this topic has been studied in much less detail than for the lithium-ion ones. Here, we explored the thermal runaway process of Na-ion pouch cells with the Na₃V₂O₂(PO₄)₂F (NVOPF)-based cathode. The thermal runaway onset temperature for such cells is noticeably higher than that for the NMC-based LIBs. We show that thermal runaway is triggered by the anode and the separator decomposition rather than by the processes at the cathode. The composition of the gas mixture released during thermal runaway process is similar to that for Li-ion batteries. The results suggest that sodium-ion batteries based on polyanionic cathodes can pave the way to safer metal-ion energy storage technologies.

Li-rich spinel materials (Li_1+xMn_2−xO₄) have shown promise for lithium-ion batteries. Nevertheless, the preparation of Li_1+xMn_2−xO₄ faces significant challenges due to the difficulty in achieving a balance between well-crystallized phases and stoichiometric chemistry. Moreover, the synthesis process is highly sensitive to calcination temperature and time, making it susceptible to phase transformations. Therefore, the rational selection of precursors and corresponding calcination procedures is absolutely essential. Herein, we make full use of the nature of metal-organic frameworks (MOFs) to achieve phase-controlled synthesis of Li(Li_0.17Mn_0.83)₂O₄ (LMO−F) spinel cathodes in 8 minutes at 500 °C. The composition and structural evolution during the pyrolysis process were systematically investigated to clarify the relationship between precursors and derivatives. Notably, the LMO−F achieved good electrochemical performance with 100.4 mAh g⁻¹ at 50 mA g⁻¹ after 100 cycles.