Electrochimica Acta最新文献_第4页

Insightful interpretation of the unique stacking faults of Na3Ni2SbO6 through cobalt doping for enhanced sodium-ion battery performance 通过掺钴深入解读 Na3Ni2SbO6 的独特堆叠断层，提高钠离子电池性能

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-27 DOI: 10.1016/j.electacta.2024.145159

The O3-Na₃Ni₂SbO₆ compound, with its hexagonal honeycomb cationic ordering, is a promising sodium-ion battery (SIB) cathode due to its phase transition steps and high average voltage. In this study, various concentrations of cobalt (Co) are doped into Na₃Ni₂SbO₆ to replace nickel (Ni), increasing disorder within the transition metal layers. Co doping introduced specific stacking faults along the c-axis direction, resulting in an ambiguous configuration of Sb/Ni(Co) within each transition metal layer, while maintaining the honeycomb order. This disorderly arrangement optimized the electronic structure and reduced the energy barrier for reactions. Na₃Ni_1.6Co_0.4SbO₆ exhibited superior performance, with a higher initial discharge capacity (137.8 mAh g^-1 at 0.1 C) and better rate performance (87 mAh g^-1 at 5 C) compared to Na₃Ni₂SbO₆ (113.6 mAh g^-1 at 0.1 C, 74 mAh g^-1 at 5 C), including improved long-term cyclic stability. The findings demonstrate that electrochemical performance can be significantly enhanced through atomic layer stacking disorder and the Na coordination environment, which is influenced by Na ion extraction and insertion, resulting in more gradual and smaller variations in lattice parameters, electronic structure, and crystal defects. This study provides a foundation for future designs of sodium-ion battery cathode materials with improved performance.

O3-Na3Ni2SbO6 化合物具有六角蜂窝状阳离子有序性，因其相变步骤和较高的平均电压而成为一种很有前途的钠离子电池（SIB）阴极。本研究在 Na3Ni2SbO6 中掺入了不同浓度的钴（Co）以取代镍（Ni），从而增加了过渡金属层的无序性。钴掺杂沿 c 轴方向引入了特定的堆叠断层，导致每个过渡金属层内的 Sb/Ni(Co)配置变得模糊不清，同时保持了蜂窝状秩序。这种无序排列优化了电子结构，降低了反应能垒。与 Na3Ni2SbO6（0.1 C 时为 113.6 mAh g-1，5 C 时为 74 mAh g-1）相比，Na3Ni1.6Co0.4SbO6 表现出更高的初始放电容量（0.1 C 时为 137.8 mAh g-1）和更好的速率性能（5 C 时为 87 mAh g-1），包括更好的长期循环稳定性。研究结果表明，电化学性能可通过原子层堆叠紊乱和 Na 配位环境得到显著提高，Na 配位环境受 Na 离子萃取和插入的影响，导致晶格参数、电子结构和晶体缺陷的变化更渐进、更小。这项研究为今后设计性能更高的钠离子电池阴极材料奠定了基础。

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引用次数: 0

Oxidative calcination-enhanced KOH activation of d-glucose-derived carbon spheres for high microporosity in supercapacitor electrodes 氧化煅烧增强 KOH 活化 d-葡萄糖衍生碳球，在超级电容器电极中实现高微孔率

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-26 DOI: 10.1016/j.electacta.2024.145151

Carbon spheres (CSs) were synthesized from d-glucose using the hydrothermal carbonization method. These CSs were impregnated using various approaches with several KOH molarities and chemically activated at 850 °C in an inert atmosphere. Calcination in air at 300 °C under room condition was used as a previous step to enhance the KOH impregnation. This process increased the impregnation of K⁺ ions onto the oxidized surface of CSs. The use of reflux at 100 °C also improved the impregnation of the activating agent allowing to increase the microporosity of the CS surfaces. CSs impregnated with the highest KOH molarity (8 M KOH) and refluxed showed the best electrochemical capacitance (CS3-rT-8 M; C_g = 283 F g^-1 at 5 mV s^-1) but due to the high KOH impregnation they lose their morphology spherical and have low yield (17.5%). CSs impregnated with 6 M KOH and refluxed preserved their spherical morphology, presented better yield (43.7%), showed the second best electrochemical capacitance (CS3-rT-6 M; C_g = 263 F g^-1 at 5 mV s^-1) and at 10 mV s^-1 ^Vage scan rate, its electrochemical capacitance is already similar (CS3-rT-6 M, C_g= 220 F g^-1; CS3-rT-8 M C_g = 227 F g^-1). For these reasons, CS3-rT-6 M could be considered as a good candidate for use as supercapacitor electrodes in practical applications.

采用水热碳化法从 d-葡萄糖合成了碳球（CSs）。这些 CS 采用不同的方法用几种摩尔的 KOH 进行浸渍，并在 850 °C 的惰性气氛中进行化学活化。前一步是在室温条件下于 300 °C 的空气中进行煅烧，以增强 KOH 的浸渍效果。这一过程增加了 K+ 离子对 CS 氧化表面的浸渍。在 100 °C 下进行回流也能提高活化剂的浸渍效果，从而增加 CS 表面的微孔。用最高摩尔度的 KOH（8 M KOH）浸渍并回流的 CS 显示出最佳的电化学电容（CS3-rT-8 M；5 mV s-1 时 Cg = 283 F g-1），但由于 KOH 浸渍度高，它们失去了球形形态，产量低（17.5%）。用 6 M KOH 浸渍并回流的 CS 保留了其球形形态，产量更高（43.7%），电化学电容次之（CS3-rT-6 M；5 mV s-1 时，Cg = 263 F g-1），在 10 mV s-1 Vage 扫描速率下，其电化学电容已相差无几（CS3-rT-6 M，Cg = 220 F g-1；CS3-rT-8 M，Cg = 227 F g-1）。因此，CS3-rT-6 M 可被视为在实际应用中用作超级电容器电极的理想候选材料。

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引用次数: 0

Micron silicon-oxide-carbon coated with TiOx(OH)y layer as better performance anode for lithium-ion batteries 涂有 TiOx(OH)y 层的微米级氧化硅-碳可用作性能更佳的锂离子电池负极

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-24 DOI: 10.1016/j.electacta.2024.145143

Micron-silicon based material is a promising anode material for high performance lithium batteries due to its ultra-high specific capacity. However, the volume expansion exceeds 300 % during charging and discharging, resulting in the collapse of the electrode structure and a rapid decline in electrochemical performance. Coating the surface of silicon-based materials with flexible ionic conductors is an effective method to maintain their high capacity and suppress swelling. Here, to further improve the electrochemical performance of silicon-based materials, we have deposited a titanate-type ionic conductor layer on a micron-sized silicon-carbon oxide (SiO_X-C) material to synthesize the SiO_X-C@TiO_x(OH)_y material. The TiO_x(OH)_y layer not only exhibits the elastic properties of a superpolymer to mitigate swelling strain, but also has a fast capacitance effect to improve its rate performance. In addition, the interfacial charge transport of SiO_X-C@TiO_x(OH)_y is enhanced due to the structural diversity of the TiO_x(OH)_y layer. For the above mechanisms, the SiO_X-C@TiO_x(OH)_y has a specific capacity of 278.3 mAh g⁻¹ under high current of 3500 mA g⁻¹. Meanwhile, the SiO_X-C@TiO_x(OH)_y with the capacity retention of 67 % is achieved at 2000 mA g⁻¹ after 100 cycles.

微米硅基材料具有超高比容量，是一种很有前途的高性能锂电池负极材料。然而，在充放电过程中体积膨胀超过 300%，导致电极结构坍塌，电化学性能迅速下降。在硅基材料表面涂覆柔性离子导体是保持其高容量和抑制膨胀的有效方法。在此，为了进一步提高硅基材料的电化学性能，我们在微米级的硅碳氧化物（SiOX-C）材料上沉积了一层钛酸酯类离子导体，合成了 SiOX-C@TiOx(OH)y 材料。TiOx(OH)y层不仅具有超聚合物的弹性特性，可减轻膨胀应变，还具有快速电容效应，从而提高了速率性能。此外，由于 TiOx（OH）y 层的结构多样性，SiOX-C@TiOx（OH）y 的界面电荷传输也得到了增强。基于上述机理，SiOX-C@TiOx(OH)y 在 3500 mA g-1 的大电流下的比容量为 278.3 mAh g-1。同时，SiOX-C@TiOx(OH)y 在 2000 mA g-1 循环 100 次后，容量保持率达到 67%。

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引用次数: 0

Elevated asymmetric supercapacitor with the nickel-metal organic framework derived nickel oxide/nickel composite: Designed to optimize efficiency and reliability 采用镍金属有机框架衍生的氧化镍/镍复合材料的不对称超级电容器：旨在优化效率和可靠性

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-24 DOI: 10.1016/j.electacta.2024.145134

In this study, a solvothermal method is used to synthesizes MOF-derived NiO/Ni composites and NiO samples at various calcination temperatures (350 °C, 450 °C, 550 °C, and 650 °C) and durations (4, 5, 6, and 7 h). The NiO/Ni sample calcined at 450 °C for 5 h (NiO/Ni-450) exhibits the highest specific capacitance (Cs) of 410 Fg⁻¹ at a scan rate of 5 mV s⁻¹. This superior performance results from the combined benefits of Ni's metallic conductivity and NiO's redox activity. In a 1 M KOH electrolyte, NiO/Ni-450 retains about 83 % of its initial capacitance after 2,000 cycles. The NiO sample formed by calcining NiO/Ni-450 for 5 h (H5) achieves a specific capacitance (Cs) of 371 Fg⁻¹ and retains 80 % of its capacitance after 2,000 cycles. NiO/Ni-450 and H5 demonstrate energy densities (Ed) of 8.58 and 5.48 Wh kg⁻¹, and power densities (Pd) of 608 and 500 W kg⁻¹, respectively. An asymmetric supercapacitor using NiO/Ni-450 and activated carbon (AC) shows an impressive 80 % capacitance retention after 9,000 cycles, with a C_s of 123 Fg⁻¹, and Ed and Pd values of 14.58 Wh kg⁻¹ and 4038 W kg⁻¹, respectively, highlighting the potential for industrial-scale production of these materials for energy storage.

本研究采用溶热法合成 MOF 衍生的氧化镍/镍复合材料和氧化镍样品，煅烧温度（350 °C、450 °C、550 °C 和 650 °C）和煅烧时间（4、5、6 和 7 小时）各不相同。在 450 °C 煅烧 5 小时的 NiO/Ni 样品（NiO/Ni-450）在 5 mV s-¹ 的扫描速率下显示出最高的比电容（Cs），达到 410 Fg-¹。这一优异性能源于 Ni 的金属导电性和 NiO 的氧化还原活性的综合优势。在 1 M KOH 电解液中，NiO/Ni-450 在循环 2,000 次后仍能保持约 83% 的初始电容。煅烧 NiO/Ni-450 5 小时后形成的 NiO 样品（H5）的比电容（Cs）达到 371 Fg-¹，在循环 2,000 次后仍能保持 80% 的电容。NiO/Ni-450 和 H5 的能量密度（Ed）分别为 8.58 和 5.48 Wh kg-¹，功率密度（Pd）分别为 608 和 500 W kg-¹。使用 NiO/Ni-450 和活性碳（AC）的非对称超级电容器在 9,000 次循环后显示出令人印象深刻的 80% 的电容保持率，Cs 为 123 Fg-¹，Ed 和 Pd 值分别为 14.58 Wh kg-¹ 和 4038 W kg-¹，突显了工业规模生产这些材料用于能量存储的潜力。

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引用次数: 0

Breaking barriers of CeO2 in energy storage: Hydrothermal energized preparation of mesoporous carbon added CeO2 nanohybrids as supercapacitor electrodes 打破 CeO2 在储能领域的障碍：水热法制备作为超级电容器电极的添加了 CeO2 的介孔碳纳米杂化物

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-24 DOI: 10.1016/j.electacta.2024.145144

Inspired by the excellent physio-chemical properties of nano-sized materials, this study details the hydrothermal preparation and electrochemical characterization of mesoporous carbon added CeO₂ nanostructures towards the energy storage applications. Cubic CeO₂ is observed for the crystal structure and phase of the prepared materials. The formation of nano-sized (∼ 7 nm) quasi spherical-like structure is found from the TEM analysis and it is mainly ascribed to the combined effect of mesoporous carbon and hydrothermal treatment. The charge storage performance of the prepared composites is examined using three-electrode mode. The capacitive behaviour of mesoporous carbon is additionally supported for electrochemical performance in addition to the battery-like behavior of the CeO₂ electrodes resulting in an increase of specific capacity by 102.6 %. Hybrid supercapacitor cell is devised and it could yield a specific energy of 31 W h kg^–1 (562 W kg^–1) and retain 81 % capacity after 3000 continuous charge discharge cycles. With this efficient composite, the future of energy storage may pave the way for more sustainable and powerful energy solutions.

受纳米材料优异的物理化学特性的启发，本研究详细介绍了水热法制备和电化学表征添加了 CeO2 的介孔碳纳米结构，以实现能量存储应用。所制备材料的晶体结构和相位为立方体 CeO2。从 TEM 分析中发现了纳米级（∼ 7 nm）准球状结构的形成，这主要归因于介孔碳和水热处理的共同作用。利用三电极模式考察了所制备复合材料的电荷存储性能。除了 CeO2 电极的类电池行为外，介孔碳的电容行为也为电化学性能提供了额外支持，从而使比容量提高了 102.6%。设计出的混合超级电容器电池可产生 31 W h kg-1 （562 W kg-1）的比能量，并在连续充放电 3000 次后保持 81 % 的容量。有了这种高效的复合材料，未来的储能技术可能会为更可持续、更强大的能源解决方案铺平道路。

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引用次数: 0

Electrochemical DNA hybridization signal amplification system using methylene blue and ascorbic acid 使用亚甲基蓝和抗坏血酸的电化学 DNA 杂交信号放大系统

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-24 DOI: 10.1016/j.electacta.2024.145146

This study presents a method for real-time monitoring of heterogeneous DNA hybridization using chronoamperometry (CA). The electrochemical assay is based on methylene blue (MB)-labeled ssDNA target (tMB) hybridization with a complementary ssDNA capture probe (p) chemisorbed to a gold electrode through the Au-S linkage. Real-time monitoring of nucleic acid binding is enabled by introducing ascorbic acid (AA) during CA measurements at oxidative potential. After hybridization, the newly formed MB-labeled double stranded DNA (ptMB) oxidized AA and, as a result, shuttled the electrons directly to the electrode. AA-ptMB electrocatalytic cycle allows amplifying the signal from hybridized MB-labeled DNA through oxidation of AA. The process consists three particular processes: hybridization of tMB to the surface probe, reaction between AA and ptMB, and (c) the electron transfer from ptMB to the electrode. We have demonstrated that system is limited by the AA-ptMB redox reaction (bimolecular constant, k = 8 ± 0.1 M^–1 s^–1). AA-ptMB cycle is sequence-specific, thus fully developed current saturation curves can be used to calculate hybridization parameters and evaluate binding kinetics under various conditions. In addition, evaluating the initial hybridization rate allows quantifying the concentration of labeled ssDNA (tMB) in several minutes. This study provides the first report of a simple electrocatalytic cycle between MB-labeled DNA and a reducer AA for monitoring DNA hybridization in real time.

本研究提出了一种利用时变分析法（CA）实时监测异质 DNA 杂交的方法。该电化学检测法基于亚甲基蓝（MB）标记的 ssDNA 目标（tMB）与通过 Au-S 连接化学吸附在金电极上的互补 ssDNA 捕获探针（p）杂交。在氧化电位下进行 CA 测量期间，通过引入抗坏血酸 (AA) 实现了对核酸结合的实时监测。杂交后，新形成的 MB 标记双链 DNA（ptMB）氧化 AA，从而将电子直接输送到电极。AA-ptMB 电催化循环可通过 AA 的氧化作用放大杂交 MB 标记 DNA 的信号。该过程包括三个特定过程：tMB 与表面探针杂交、AA 与 ptMB 反应，以及 (c) 电子从 ptMB 转移到电极。我们已经证明，该系统受到 AA-ptMB 氧化还原反应的限制（双分子常数 k = 8 ± 0.1 M-1 s-1）。AA-ptMB 周期是序列特异性的，因此，完全开发的电流饱和曲线可用于计算杂交参数和评估各种条件下的结合动力学。此外，评估初始杂交速率可在几分钟内量化标记 ssDNA（tMB）的浓度。本研究首次报道了 MB 标记 DNA 与还原剂 AA 之间的简单电催化循环，用于实时监测 DNA 杂交。

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引用次数: 0

In situ design of bimetallic CoFe-MOF on carbon cloth with abundant oxygen vacancies for advanced flexible asymmetric supercapacitors with high energy density 在具有丰富氧空位的碳布上原位设计双金属 CoFe-MOF，用于制造具有高能量密度的先进柔性不对称超级电容器

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-24 DOI: 10.1016/j.electacta.2024.145141

Flexible supercapacitors have attracted great attention owing to high power density, long cycling stability and bending property. However, their energy density is mainly limited by the electrodes. Because of the limited redox active sites and low electrical conductivity, to design the cobalt-based metal-organic framework (MOF) materials with high specific capacitance remains a huge challenge. The bimetallic CoM-MOF@CC (M = Ni, Cu, Al, Fe) composites were in situ produced on flexible carbon cloth (CC) to coordinate the advantages of bimetallic active sites. The O_v-CoFe-MOF@CC assembled with ultra-small nanoparticles, provided abundant oxygen vacancies and optimized combination of Fe and Co active metal centers. Benefiting from the synergistic merits of optimized pore structure, high electrical conductivity and increased active sites utilization, the O_v-CoFe-MOF@CC electrode achieved high area-specific capacitance of 56.94 mF cm⁻² at 0.5 mA cm⁻², along with high capacitance retention of 99.67% over 30,000 cycles. The asymmetric flexible capacitor assembled with O_v-CoFe-MOF@CC anode and NCM@CC cathode showing an exceptionally extended cycling life, high energy density of 27.4 mWh cm⁻²and power density of 4798.98 mW cm⁻², which highlights the great potential for high energy storage.

柔性超级电容器具有高功率密度、长周期稳定性和弯曲特性，因此备受关注。然而，其能量密度主要受到电极的限制。由于氧化还原活性位点有限且导电率低，设计具有高比电容的钴基金属有机框架（MOF）材料仍然是一个巨大的挑战。为了协调双金属活性位点的优势，我们在柔性碳布（CC）上原位制备了双金属 CoM-MOF@CC（M = Ni、Cu、Al、Fe）复合材料。由超小型纳米颗粒组装而成的 Ov-CoFe-MOF@CC 提供了丰富的氧空位以及铁和钴活性金属中心的优化组合。得益于优化的孔隙结构、高导电性和活性位点利用率提高等协同优势，Ov-CoFe-MOF@CC 电极在 0.5 mA cm-2 电流条件下实现了 56.94 mF cm-2 的高面积比电容，并且在 30,000 次循环中实现了 99.67% 的高电容保持率。由 Ov-CoFe-MOF@CC 阳极和 NCM@CC 阴极组装而成的非对称柔性电容器具有超长的循环寿命、27.4 mWh cm-2 的高能量密度和 4798.98 mW cm-2 的功率密度，彰显了其在高能量存储方面的巨大潜力。

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引用次数: 0

Enhanced protonic and oxygen-ionic conductivity in Ga-doped Nd2Ce2O7 electrolytes for intermediate-temperature solid oxide fuel cell 用于中温固体氧化物燃料电池的掺镓 Nd2Ce2O7 电解质中增强的质子和氧离子电导率

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-24 DOI: 10.1016/j.electacta.2024.145142

Developing mixed oxygen-ion and proton conductors with high ionic conductivity is crucial for advancing intermediate temperature-solid oxide fuel cell (IT-SOFC). In this study, a novel Nd_2-xGa_xCe₂O₇ (NGCO, x = 0, 0.05, 0.075, 0.10 and 0.15) ceramic is synthesized by the citric acid-nitrate sol-gel combustion process. The influence of Ga doping on crystal structure, oxygen vacancy, morphology, proton transport characteristic and electrochemical performance of this materials is systematically investigated. It is found that the NGCO exhibits the fluorite-type structure and belongs to space group Fm

\bar{3}

m. NGCO shows remarkable chemical stability, resisting harmful effects from CO₂, water, and wet hydrogen exposure. Adding a small amount of Ga results in high-density ceramics with enlarged grain size and reduced grain boundary density. Nd_1.925Ga_0.075Ce₂O₇ (7.5NGCO) displays outstanding conductivities, exceeding Nd₂Ce₂O₇ (NCO) by 271.4% and 248.6% in dry air and wet hydrogen conditions. Further, an anode-supported structure fuel cell with 7.5NGCO electrolyte is constructed and evaluated. The peak power density (PPD) at 700 °C reaches 702 mW/cm², a 96% enhancement over the fuel cells with NCO electrolyte. These findings indicate that Ga-doped NCO electrolyte holds promise as a proton-conducting electrolyte suitable for IT-SOFC.

开发具有高离子电导率的氧离子和质子混合导体对于推动中温固体氧化物燃料电池（IT-SOFC）的发展至关重要。本研究采用柠檬酸-硝酸盐溶胶-凝胶燃烧工艺合成了一种新型 Nd2-xGaxCe2O7 （NGCO，x = 0、0.05、0.075、0.10 和 0.15）陶瓷。系统研究了掺杂镓对该材料晶体结构、氧空位、形貌、质子传输特性和电化学性能的影响。研究发现，NGCO呈萤石型结构，属于空间群Fm3¯m。NGCO 显示出卓越的化学稳定性，能抵御二氧化碳、水和湿氢暴露的有害影响。加入少量镓后，高密度陶瓷的晶粒尺寸增大，晶界密度降低。Nd1.925Ga0.075Ce2O7（7.5NGCO）具有出色的电导率，在干燥空气和湿氢条件下分别比 Nd2Ce2O7（NCO）高出 271.4% 和 248.6%。此外，还构建并评估了采用 7.5NGCO 电解质的阳极支撑结构燃料电池。700 °C 时的峰值功率密度（PPD）达到 702 mW/cm2，比使用 NCO 电解质的燃料电池提高了 96%。这些研究结果表明，掺镓 NCO 电解质有望成为适用于 IT-SOFC 的质子传导电解质。

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引用次数: 0

Compositional dependence of electrochemical properties in biopolymer blend-based solid electrolytes doped with sodium perchlorate for EDLC applications 掺杂高氯酸钠的生物聚合物混合型固体电解质的电化学性能与成分有关，适用于 EDLC 应用

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-23 DOI: 10.1016/j.electacta.2024.145139

Biopolymer-based blends of solid electrolytes capable of conducting sodium ions were prepared via solution casting by incorporating sodium carboxymethyl cellulose (NaCMC) and polyvinyl alcohol (PVA) with varying concentrations of sodium perchlorate monohydrate (NaClO₄.H₂O), which was used as the dopant. The prepared electrolytes were characterized to reveal their structural, vibrational, electrical, and electrochemical properties that make them promising as solid polymer electrolytes (SPEs). X-ray diffraction (XRD) analysis showed that the amorphous nature of the sample increased with the addition of NaClO₄.H₂O salt concentrations of up to 30 wt.%. The complexation between the polymers and salt was confirmed by Fourier-Transform Infrared (FTIR) analysis. The SPE exhibited an optimal ionic conductivity of (1.90 ± 0.05) ×10⁻⁵ S cm⁻¹, which is three orders higher than that of the pristine polymer blend with (5.31 ± 0.61) ×10⁻⁸ S cm⁻¹, as determined by electrochemical impedance spectroscopy (EIS) analysis. Scaling studies conducted based on AC conductivity and tangent loss revealed that these measurements could be represented by a single master curve, which suggests that the optimal sample adheres to the time-temperature superposition principle (TTSP). The temperature dependence of Jonscher's exponent indicates that the conduction mechanism can be effectively represented by the Quantum Mechanical Tunneling model (QMT). Both transference number measurement (TNM) and linear sweep voltammetry (LSV) analyses validated the electrolyte's suitability for energy device applications by demonstrating its high ion transference number and electrochemical potential window of 3.93 V. The optimized SPE film was subsequently utilized in an electrochemical double-layer capacitor (EDLC) device to evaluate its performance as both an electrolyte and separator. The supercapacitor exhibited an impressive energy density of 15.18 Wh kg⁻¹ and a power density of 4512.5 W kg⁻¹, along with remarkable stability in terms of cycle life.

通过溶液浇注法，将羧甲基纤维素钠（NaCMC）和聚乙烯醇（PVA）与不同浓度的一水高氯酸钠（NaClO4.H2O）（用作掺杂剂）混合，制备了能够传导钠离子的生物聚合物基固体电解质混合物。对制备的电解质进行了表征，揭示了它们的结构、振动、电学和电化学特性，这些特性使它们有望成为固体聚合物电解质（SPE）。X 射线衍射 (XRD) 分析表明，随着 NaClO4.H2O 盐浓度增加到 30 wt.%，样品的无定形性质也随之增加。傅立叶变换红外（FTIR）分析证实了聚合物与盐之间的络合作用。根据电化学阻抗光谱（EIS）分析，SPE 的最佳离子电导率为 (1.90 ± 0.05) ×10-5 S cm-1，比原始聚合物混合物的 (5.31 ± 0.61) ×10-8 S cm-1 高三个数量级。根据交流电导率和正切损耗进行的缩放研究表明，这些测量结果可以用一条主曲线来表示，这表明最佳样品符合时间-温度叠加原理（TTSP）。Jonscher指数的温度依赖性表明，量子力学隧道模型（QMT）可以有效地代表传导机制。转移数测量（TNM）和线性扫描伏安法（LSV）分析都证明了这种电解质的高离子转移数和 3.93 V 的电化学电位窗口，从而验证了它在能源设备应用中的适用性。该超级电容器的能量密度为 15.18 Wh kg-1，功率密度为 4512.5 W kg-1，循环寿命非常稳定。

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引用次数: 0

Fabrication of asymmetric supercapacitor device with NiCo2O4@reduced graphene oxide nanocomposites 用镍钴氧化物@还原氧化石墨烯纳米复合材料制造不对称超级电容器装置

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2024-09-23 DOI: 10.1016/j.electacta.2024.145118

In the present work, spinel-like nickel cobalt oxide (NiCo₂O₄) is prepared through a facile and cost-effective co-precipitation method. To enhance the electrochemical characteristics of NiCo₂O₄, the material is incorporated into reduced graphene oxide (rGO) sheets to form a nanocomposite. The FESEM and HRTEM characterizations of the nanocomposite confirms the successful formation of the NiCo₂O₄@rGO. The nitrogen (N₂) adsorption-desorption study reveals the mesoporous nature of both materials, with specific surface areas of 301.18 m² g⁻¹ for NiCo₂O₄@rGO and 54.00 m² g⁻¹ for pristine NiCo₂O₄. Galvanostatic Charge-Discharge (GCD) results indicate that NiCo₂O₄@rGO nanocomposite exhibits nearly four-fold better electrochemical performance compared to pristine NiCo₂O₄. The specific capacity values are 787.17 C g⁻¹ for NiCo₂O₄@rGO and 194.56 C g⁻¹ for NiCo₂O₄ at 1.0 A g⁻¹. The practical utility of the material is showcased through an assembly of asymmetric supercapacitor (ASC) device with the configuration NiCo₂O₄@rGO//Activated Carbon (AC). This device demonstrates high energy density and power density, measured as 46.01 Wh kg⁻¹ and 936.69 W kg⁻¹ at 10 A g⁻¹, and 25.12 Wh kg⁻¹ and 2810.08 W kg⁻¹ at 30 A g⁻¹. The performance of the supercapacitor is further illustrated by illuminating two arrays of LED lights, designed to spell out NITK and KUK. The LEDs illuminate for 10 min and 15 min, respectively, and both arrays together for about 10 min with bright intensity. This work demonstrates the great potential of the NiCo₂O₄@rGO nanocomposite electrodes for energy storage applications with superior performance.

在本研究中，通过一种简便且经济有效的共沉淀方法制备了尖晶石状氧化镍钴（NiCo2O4）。为了增强镍钴氧化物的电化学特性，将该材料加入还原氧化石墨烯（rGO）片中形成纳米复合材料。纳米复合材料的 FESEM 和 HRTEM 表征证实了 NiCo2O4@rGO 的成功形成。氮（N2）吸附-解吸研究揭示了这两种材料的介孔性质，NiCo2O4@rGO 的比表面积为 301.18 m2 g-1，原始 NiCo2O4 的比表面积为 54.00 m2 g-1。电静态充放电（GCD）结果表明，与原始 NiCo2O4 相比，NiCo2O4@rGO 纳米复合材料的电化学性能提高了近四倍。在 1.0 A g-1 的条件下，NiCo2O4@rGO 的比容量值为 787.17 C g-1，而 NiCo2O4 的比容量值为 194.56 C g-1。该材料的实用性通过一个配置为 NiCo2O4@rGO//Activated Carbon（AC）的非对称超级电容器（ASC）装置的组装得到了展示。该装置具有很高的能量密度和功率密度，在 10 A g-¹ 时，能量密度和功率密度分别为 46.01 Wh kg-¹ 和 936.69 W kg-¹；在 30 A g-¹ 时，能量密度和功率密度分别为 25.12 Wh kg-¹ 和 2810.08 W kg-¹。超级电容器的性能还可以通过点亮两个 LED 灯阵列来进一步说明，这两个 LED 灯阵列的设计分别代表 NITK 和 KUK。LED 灯分别点亮 10 分钟和 15 分钟，两个阵列一起点亮约 10 分钟，亮度很高。这项工作证明了 NiCo2O4@rGO 纳米复合电极在储能应用中的巨大潜力和卓越性能。

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