MnO2@ACFF中间层强化高载量硫电极性能稳定性作用

为提高碳材料对聚硫化物的吸附能力,将MnO₂原位化学沉积于活性碳纤维炭毡(ACFF)的碳纤维表面,得到了聚硫化物吸附强化的多孔导电材料(MnO₂@ACFF)。将其作为中间层设置于隔膜和硫电极之间,有效控制了高载量硫电极的聚硫离子穿梭,提高了活性物质利用率和库伦效率,降低了电极极化和电化学反应阻抗,提高了电极循环稳定性,避免了锂硫电池的突然失效。在2 mA/cm²的电流密度下,载硫量为15 mg/cm²的硫电极经过350次充放电循环仍保有430 mA·h/g的比容量。提高硫电极载硫量虽然使电极的循环稳定性下降,但载量为20 mg/cm²和30 mg/cm²的硫电极0.1 C下经过100次循环,仍分别保有736 mA·h/g和446 mA·h/g的比容量,比容量保持率为65%,而且面积比容量和面积比能量也能分别保持64%和42%,高于当前锂离子电池的面积比容量和面积比能量。     

卤离子调控的镍钴基电极材料生长及电容影响研究

超级电容器是很有发展潜力的电化学储能器件,其性能主要取决于电极材料。利用水热法,通过改变加入的卤离子（F^-、Cl^-、Br^-）种类,可以简便地对镍钴（NiCo）基超级电容器电极材料的形貌、物相以及化学组成进行调控。由X射线衍射（XRD）和扫描电镜（SEM）等表征结果可知,F^- 诱导生成纳米片支撑纳米线阵列,成分为稳定的NiCo LDH结构;Cl^-/Br^- 诱导生成纳米线,成分为碱式碳酸钴。从电化学测试结果可知,形貌和晶型对电化学性能有显著的影响。其中Cl^- 调控的电极在120 ℃下反应3 h时,其形貌为纳米线,晶型偏向无定形,此时性能最优;在2 mA/cm²电流密度下不仅具有最大的面积比电容2 940 mF/cm²,且该电极与负极活性炭组装的器件具有1.8 V的大电压窗口和优异的循环稳定性。     

锂-氧气电池用泡桐木衍生三维自支撑Co、N、S共掺杂多孔炭

正极是锂-氧气（Li-O₂）电池的电化学反应场所，其直接决定了电池性能。本研究采用泡桐木为原材料，在NaCl/CoCl₂混合熔融盐介质中，以三聚氰胺和硫脲为氮源和硫源，一步热解炭化制备出Co、N、S共掺杂的三维自支撑多孔炭材料（wd-NSC），并直接用作Li-O₂电池正极。利用X射线衍射、扫描电镜、透射电镜、氮气吸脱附、拉曼光谱、X射线光电子能谱等对所获三维自支撑多孔炭材料的形貌、晶体结构与化学成分进行了表征。研究结果表明，Co、N、S共掺杂的三维自支撑多孔炭材料表现出高比容量（在0.05mA/cm²的电流密度下，放电比容量可达12.83mA·h/cm²）和出色的循环稳定性（在电流密度为0.1mA/cm²和限定容量为0.5mA·h/cm²下，循环寿命可达125次），优异的电池性能可归因于三维分级多孔结构及Co、N、S共掺杂的协同作用。     

自支撑Ni/MoN@NCNT的制备及其析氢性能

非贵金属基电催化剂的合理设计与合成,对降低HER过电位,提升电解水产氢效率具有重要意义。因此在泡沫铜表面合成了包含Ni/MoN与氮掺杂碳复合材料(Ni/Mo-NCNT)。当电流密度为10 mA/cm²时,展现出117 mV的HER过电位,并且500 mA/cm²电流密度下仅需要300 mV的过电位。     

基于阴离子交换反应的NiMn-LDH电极电容性能提升研究

采用一步水热法在泡沫镍网上原位生长镍锰基层状双氢氧化物（NiMn-LDH）纳米片阵列电极,并通过氢氧化钾溶液中浸泡的方式提升电极的容量。采用SEM、XRD、TEM和XPS等手段对浸泡前后的电极材料进行表征。结果表明,在浸泡前后NiMn-LDH电极的形貌没有变化,但在电极材料内部发生了明显的CO₃^2-和OH^-的交换反应,降低体积较大的CO₃^2-在LDH层间的分布数量,使层内空间成为OH^-的“蓄水池”,缩短了电荷存储过程中OH^-的迁移距离,因此电容性能有了明显提升。电化学测试结果表明,在5 mA/cm²电流密度下,电极的比电容从18.0 F/g增加至766.6 F/g（1.69 F/cm²）。将该电极与活性炭组装的全固态不对称超级电容器在功率密度为900 W/kg时,可呈现的能量密度为35.9 W·h/kg,并且器件的循环稳定性良好。     

CoO@CuO电极材料制备及超级电容性能研究

超级电容器因具有功率密度高、充放电速率快、循环使用寿命长等优点而备受关注。CoO是一种优良的超级电容电极材料,理论比容量可以达到4 292 F·g^-1,但其电导率较低,而且充放电过程中会产生体积膨胀,导致其实际比容量低于理论比容量。为此,本文首先采用热氧化法在泡沫铜导电集流体上生长CuO纳米线阵列,然后采用化学浴沉积法在CuO纳米线表面沉积CoO层级结构,制备核壳结构CoO@CuO电极材料。该电极材料在电流密度为2 mA·cm^-2时的比容量可达到1.043 0 F·cm^-2(117.145 3 F·g^-1),并表现出了良好的电容保持率。     

水热法制备氧化钴/泡沫镍材料及电容性能分析

利用简单的水热法制备出不同反应液浓度、不同反应时间以及不同反应温度氧化钴/泡沫镍（CoO/NF）电极，旨在改善氧化钴材料的比电容及稳定性。通过XRD、SEM、TEM、EDS Mapping和BET对其结构和形貌进行了表征，同时在1mol/L氢氧化钾（KOH）电解液中采用循环伏安曲线（CV）、充放电曲线（CP）、循环性能测试、大电流充放电测试以及交流阻抗（EIS）测试研究了其电化学性能。表征结果显示氧化钴均匀地分布在泡沫镍载体表面，且片状结构CoO-8h/NF具有较大的比表面积和多孔特性。在三电极体系中，电化学测试结果显示CoO-8h/NF在1mA/cm²电流密度下表现出最好的电容性能，比电容可以达到930mF/cm²。在10mA/cm²电流密度下对CoO-8h/NF电极进行10000次恒电流充放电测试，循环测试后电极的比电容几乎没有衰减，具有较好的稳定性，是超级电容器比较理想的正极材料。     

纳米多孔CuMn基氧化物电极的制备及性能

铜氧化物由于具有理论容量高和储量丰富等优势成为下一代有前景的超级电容器电极材料，但其电子导电性低和长期循环稳定性差制约实际应用。本文以三明治型Cu₃₀Mn₇₀/Cu/Cu₃₀Mn₇₀箔带为母合金，通过脱合金与自蔓延氧化相结合的技术制备了高导电柔性纳米多孔CuMn@多组元氧化物核-壳复合电极，并探究了不同脱合金条件下Mn残余量对电极形貌、结构和电化学性能的影响。实验结果表明，随着腐蚀时间的延长，Mn的残余量会逐渐变少，而不同腐蚀条件下获得的多组元氧化物均由CuO、Cu₂O、Cu_xMn_1-xO和CuMn₂O₄相组成。腐蚀时间为50min时制备的电极(NP-TMO5)在三电极体系测试中具有最优的电化学性能：5mA/cm²电流密度下，面积比电容为1045.7mF/cm²，且循环12000次后，电容保持率为95.9%。两电极对称体系测试中，3mA/cm     

竹炭深加工及在能源电池中应用的研究

以天然毛竹材为原料,通过高温炭化、活化等处理后,得到具有高比表面积的竹炭基生物质能源电池材料。通过恒流充放电、循环伏安等电化学测试方法,考察了竹炭作为超级电容器及锂离子电池电极材料时的电化学性能。结果表明:采用KOH活化后得到的竹炭,比表面积可达2366m2/g;用作超级电容器电极材料,比容量可以达到205F/g,并表现出良好的充放电效率。作为锂离子电池负极材料在200mA/g的电流密度下30次循环后仍然具有225mA·h/g,显示了竹炭具有较高的比容量及良好的循环性能和倍率性能,作为新能源材料具有广泛的应用前景。     

铁氮改性纳米金刚石的制备及其电化学性能研究

利用爆轰纳米金刚石(ND)导热性极强的特点，将尺寸较小的反应物前驱体分布在ND表面后产生需要的金属盐再进行氮掺杂，成功制备出高效氧还原反应催化剂Fe-NND并应用于锌-空电池。结果表明，其ORR反应过程电子转移数为3.91,起始电位为0.903 6 V,电流密度高达5.225 mA/cm²,且经过6 000圈CV循环其半波电位仅下降26 mV。在锌-空电池上的峰值功率密度为91.81 mW/cm²,比容量高达847 mA·h/g。     

An asymmetric supercapacitor using RuO2/TiO2 nanotube composite and activated carbon electrodes

We reported an asymmetric supercapacitor technology where RuO₂/TiO₂ nanotube composite was used as positive electrode and the activated carbon as negative electrode in 1 mol/L KOH electrolyte solution. The electrochemical capacitance performance of the asymmetric supercapacitor was tested by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge tests. The results show that the asymmetric supercapacitor has electrochemical capacitance performance within potential range 0–1.4 V. A power density 1207 W/kg was obtained with an energy density of 5.7 W h/kg at a charge–discharge current density of 120 mA/cm². The supercapacitor also exhibits a good cycling performance and keep 90% of initial capacity over 1000 cycles.     

氧化镍/碳纳米管构筑准固态不对称超级电容器及电化学性能

以Ni(NO₃)₂为原料、NaOH为沉淀剂和羟基化碳纳米管（CNT）为基质首先制备了Ni(OH)₂/CNT复合材料, 然后将其于一定温度下煅烧，使其转变为NiO/CNT复合材料。用X射线粉末衍射仪（XRD）、场发射电子显微镜（FESEM）和透射电子显微镜（TEM）表征了样品的晶相与形貌，结果表明NiO纳米粒子紧密锚附在碳纳米管表面。复合材料可能的形成机理被提出。采用循环伏安法（CV）、单电极充放电和电化学阻抗研究了反应条件对其电化学性能的影响，确定最佳制备条件。将复合材料正极、活性炭负极和PVA-KOH电解质膜组装成准固态不对称超级电容器，电化学性能测试结果表明，在充放电电流密度11.2mA/cm²下，其比电容达到868.0F/g并保持稳定循环3700圈。7500次循环后，其比电容值仍有564.2F/g，显示出高的比电容和长的循环稳定性。     

Construction of NiCo2O4 nanoflake arrays on cellulose-derived carbon nanofibers as a freestanding electrode for high-performance supercapacitors

Cellulose has a wide range of applications in many fields due to their naturally degradable and low-cost characteristics, but few studies can achieve cellulose-nanofibers by conventional electrospinning. Herein, we demonstrate that the freestanding cellulose-based carbon nanofibers are successfully obtained by a special design of electrospinning firstly, pre-oxidation and high-temperature carbonization (1600 °C), which display a superior electrical conductivity of 31.2 S·cm^–1 and larger specific surface area of 35.61 m²·g^–1 than that of the polyacrylonitrile-based carbon nanofibers (electrical conductivity of 18.5 S·cm^–1, specific surface area of 12 m²·g^–1). The NiCo₂O₄ nanoflake arrays are grown uniformly on the cellulose-based carbon nanofibers successfully by a facile one-step solvothermal and calcination method. The as-prepared cellulose-based carbon nanofibers/NiCo₂O₄ nanoflake arrays are directly used as electrodes to achieve a high specific capacitance of 1010 F·g^–1 at 1 A·g^–1 and a good cycling stability with 90.84% capacitance retention after 3000 times at 10 A·g^–1. Furthermore, the all-solid-state symmetric supercapacitors assembled from the cellulose-based carbon nanofibers/NiCo₂O₄ deliver a high energy density of 62 W·h·kg^–1 at a power density of 1200 W·kg^–1. Six all-solid-state symmetric supercapacitors in series can also power a ‘DHU’ logo consisted of 36 light emitting diodes, confirming that the cellulose-based carbon nanofiber is a promising carbon matrix material for energy storage devices.     

NiCo2O4@quinone-rich N–C core–shell nanowires as composite electrode for electric double layer capacitor

The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability. Considering the close connection between their performance and the amount of carbon material loaded on the electrodes, in this work, NiCo₂O₄ nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction. Then, the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo₂O₄ nanowires, and the obtained composite was used as electrode for electric double layer capacitor. The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF∙cm^–2 at the current density of 1 mA∙cm^–2. The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW∙h∙cm^–3 at a power density of 180 mW∙cm^–3. The assembled symmetric capacitor exhibited a capacitance retention of 88.96% after 10000 charge/discharge cycles at the current density of 20 mA∙cm^–2. These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.     

木质素基活性炭氮掺杂改性及其电化学性能

以磷酸法木质素基活性炭为原料, 三聚氰胺为氮源、KOH为活化剂, 采用同步掺杂方式制备了氮掺杂活性炭(NAC)。通过BET、XRD、拉曼光谱和XPS表征手段测试了改性后活性炭的结构及其组分, 并通过电化学表征手段, 测试了其作为超级电容器电极材料在几种不同性质电解液中的性能, 初步探究了电解液对电极材料电化学性能的影响机制。实验结果表明: 改性后的活性炭具有丰富的孔结构, 比表面积达到2 332 m²/g, 微孔孔容为1.37 cm³/g, 中孔孔容为0.74 cm³/g, 平均孔径为2.79 nm, 含氮元素7.5%, 其中类石墨型氮(N-Q)结构达到34.6%。丰富的孔结构和氮含量大幅提升了活性炭的电化学性能, 其在水系电解液中展现出了高比电容, 在1 A/g的电流密度下比电容最高可达424 F/g; 在有机系电解液中, 尽管其在1 A/g的电流密度下比电容最高仅为87 F/g, 由于其工作电压窗口更宽(0~2.5 V), 因此具备了更高的能量密度。对结果进行分析, 发现: 活性炭电极材料在水系电解液中的性能主要受电解液水合离子半径影响, 而在有机系电解液中的性能主要受电解液黏度的影响。     

椰壳基超级电容活性炭的制备及其电化学性能研究

以椰壳炭化料为原料,KOH为活化剂,在不同工艺条件下制备了超级电容器用活性炭电极材料。考察了碱炭比、活化温度和活化时间对活性炭孔隙结构及其用作电极材料的比电容的影响。结果表明,在KOH与椰壳炭化料质量比为4:1,活化温度800℃,活化时间60 min的条件下,可制得比表面积2891 m²/g,总孔容积1.488 cm³/g,中孔率73.6%,比电容达235 F/g的优质活性炭电极材料。     

Electrospun porous carbon nanofibers derived from bio-based phenolic resins as free-standing electrodes for high-performance supercapacitors

Phenolic resins were employed to prepare electrospun porous carbon nanofibers with a high specific surface area as free-standing electrodes for high-performance supercapacitors. However, the sustainable development of conventional phenolic resin has been challenged by petroleum-based phenol and formaldehyde. Lignin with abundant phenolic hydroxyl groups is the main non-petroleum resource that can provide renewable aromatic compounds. Hence, lignin, phenol, and furfural were used to synthesize bio-based phenolic resins, and the activated carbon nanofibers were obtained by electrospinning and one-step carbonization activation. Fourier transform infrared and differential scanning calorimetry were used to characterize the structural and thermal properties. The results reveal that the apparent activation energy of the curing reaction is 89.21 kJ·mol^–1 and the reaction order is 0.78. The activated carbon nanofibers show a uniform diameter, specific surface area up to 1100 m²·g^–1, and total pore volume of 0.62 cm³·g^–1. The electrode demonstrates a specific capacitance of 238 F·g^–1 (0.1 A·g^–1) and good rate capability. The symmetric supercapacitor yields a high energy density of 26.39 W·h·kg^–1 at 100 W·kg^–1 and an excellent capacitance retention of 98% after 10000 cycles. These results confirm that the activated carbon nanofiber from bio-based phenolic resins can be applied as electrode material for high-performance supercapacitors.