配碳量对放电等离子烧结无粘结剂纳米WC硬质合金的影响

研究了配碳量对放电等离子烧结制备无粘结剂纳米WC硬质合金的烧结行为、相组成、致密度、硬度及晶粒大小的影响。结果表明：纯纳米WC粉直接烧结，样品的晶粒度为300～400nm，致密度及硬度均较高，但主相变为缺碳相WC1-x和W2C配碳量为0．05％～0．25％时，样品中有少量缺碳相；配碳量为0．40％时，可以正确成相；配碳量为0．50％时，则出现游离碳；粉末配碳球磨后，因烧结过程提前到较低温度下完成，1800℃烧结时晶粒急剧长大且不均匀。     

Feather-like NiCo2O4 self-assemble from porous nanowires as binder-free electrodes for low charge transfer resistance

The unique feather-like arrays composing of ultrathin secondary nanowires are fabricated on nickel foam (NF) through a facile hydrothermal strategy. Thus, the enhancement of electrochemical properties especially the low charge transfer resistance strongly depends on more active sites and porosity of the morphology. Benefiting from the unique structure, the optimized NiCo₂O₄ electrode delivers a significantly lower charge transfer resistance of 0.32 Ω and a high specific capacitance of 450 F·g⁻¹ at 0.5 A·g⁻¹, as well as a superior cycling stability of 139.6% capacitance retention. The improvement of the electrochemical energy storage property proves the potential of the fabrication of various binary metal oxide electrodes for applications in the electrochemical energy field.     

Synergistic Bimetallic CoCu-Codecorated Carbon Nanosheet Arrays as Integrated Bifunctional Cathodes for High-Performance Rechargeable/Flexible Zinc-Air Batteries

The unremitting exploration of well-architectured and high-efficiency oxygen electrocatalysts is promising to speed up the surface-mediated oxygen reduction/evolution reaction (ORR/OER) kinetics of rechargeable zinc–air batteries (ZABs). Herein, bimetallic CoCu-codecorated carbon nanosheet arrays (CoCu/N-CNS) are proposed as self-supported bifunctional oxygen catalysts. The integrated catalysts are in situ constructed via a simple sacrificial-templated strategy, imparting CoCu/N-CNS with 3D interconnected conductive pathways, abundant mesopores for electrolyte penetration and ion diffusion, as well as Cu-synergized Co – N_x/O reactive sites for improved catalytic activities. By incorporating a moderate amount of Cu into CoCu/N-CNS, the bifunctional activities can be further increased due to synergistic oxygen electrocatalysis. Consequently, the optimized CoCu/N-CNS realizes a low overall overpotential of 0.64 V for OER and ORR and leads to high-performance liquid ZABs with high gravimetric energy (879.7 Wh kg⁻¹), high peak power density (104.3 mW cm⁻²), and remarkable cyclic stability upon 400 h/1000 cycles at 10 mA cm⁻². More impressively, all-solid-state flexible ZABs assembled with the CoCu/N-CNS cathode exhibit superior rate performance and exceptional mechanical flexibility under arbitrary bending conditions. This CoCu/N-CNS monolith holds significant potential in advancing cation-modulated multimetallic electrocatalysts and multifunctional nanocatalysts.     

三维网络结构氧化铜纳米线锂离子电池负极材料的制备和性能研究

通过阳极氧化法和后退火处理在铜箔上合成了三维网络结构氧化铜纳米线,将其作为负极材料制备了无需添加粘结剂的锂离子电池。研究了恒压氧化时间对材料形貌和电化学性能的影响。在1C的倍率下,氧化1000 s制备的CuO纳米线表现出最高的1172 mAh/g首圈放电比容量和594 mAh/g的可逆比容量,500圈循环可逆比容量为607.6 mAh/g,可逆容量保留率为102.3%。交联的三维网络结构CuO纳米线相互支撑,提供稳定的结构,有效缓解了CuO纳米线作为锂离子电池负极材料中的体积膨胀问题,表现出了优异的倍率性能和循环寿命。     

FPC材料的技术动向

概述了FPC的技术开发动向和FPC材料的技术动向。     

Binder-Free Electrodes for Advanced Sodium-Ion Batteries

Sodium-ion batteries (SIBs) have recently emerged as one of the favored contenders for use in medium and large-scale stationary energy storage owing to the abundance of the resources required to fabricate them, their low cost, and the fact that have properties similar to equivalent Li batteries. However, their development also faces challenges such as poor cycling stability and unsatisfying rate performance. In traditional electrodes, binders are commonly used to integrate individual active materials with conductive additives. Unfortunately, binders are generally electrochemically inactive and insulating, which reduces the overall energy density and leads to poor cycling stability. Therefore, binder-free electrodes provide great opportunity for high-performance SIBs in terms of both improved electronic conductivity and electrochemical reaction reversibility. This Progress Report provides an overview of the recent progress in binder-free electrodes for SIBs. It focuses on the current challenges of binder-free electrodes and provides an outlook for their future in energy conversion and storage.     

无粘结剂MCM-22分子筛催化剂制备及其催化性能

采用NaOH溶液对含粘结剂的成型工业MCM-22分子筛催化剂进行后处理以脱除粘结剂,制备无粘结剂MCM-22分子筛催化剂,并实验考察了碱浓度、处理时间对催化剂的强度、活性组分的含量、酸量及催化性能的影响。结果表明:在NaOH溶液的质量分数为0.3%、150℃的条件下对圆柱形含粘结剂MCM-22分子筛催化剂处理4h,即可制得无粘结MCM-22分子筛催化剂。在苯与乙烯液相烷基化反应中,在苯与乙烯物质的量比为3.0,乙烯质量空速为9.0h~(-1),温度200℃,压力3.5 MPa的反应条件下,无粘结剂MCM-22分子筛催化剂的乙烯转化率维持在60%以上,催化性能与分子筛原粉相当,明显优于含粘结剂的催化剂(低于40%),且其强度能够满足工业应用的要求。     

铜基底上无黏结剂Co3V2O8多孔纳米片阵列的制备以及锂离子电池性能研究

直接在铜基底上生长具有不同金属离子的多孔过渡金属氧化物,成为有前途的锂离子电池电极材料的候选。本文提出了一种简便可行的低温水热沉积方法在铜基底上制备前驱物阵列。前驱物经过煅烧处理得到具有多孔特性Co₃V₂O₈纳米片阵列,多孔纳米片阵列用作锂离子电池负极材料显示出了长期循环稳定性和高倍率性能。在1.0 A/g电流密度下,电池经过240次循环后显示出1 010 mA∙h/g的容量;在3.0 A/g的电流密度下,电池循环600次后显示出552 mA∙h/g的可逆容量。     

无粘结剂三维石墨烯-硫正极的电化学性能研究

为提高电极中硫的负载量,采用水热法和热处理法制备了锂硫电池用无粘结剂三维石墨烯-硫正极材料,用比表面积测试仪、电子扫描电镜、电化学工作站以及电池测试系统对电极的比表面积、微观表面形貌和电化学性能进行了表征.结果表明:所制备的无粘结剂三维石墨烯-硫电极的最高放电比容量为517.3 mAh/g,50次循环后,放电比容量仍能保持在448.9 mAh/g,表现出较高的比容量和良好的循环性能.     

Carbon nanofiber activated by molybdenum disulfide as an effective binder-free composite anode for highly reversible lithium storage

Carbon nanofiber film (CNF) as anode material for lithium-ion batteries (LIBs) draws attention for its excellent cyclic stability, but its practical application is limited due to low specific capacity. Considering the advantages of pure CNF and MoS₂, a flexible film which CNF covered by MoS₂ (MoS₂/CNF) is successfully produced and evaluated as a binder-free electrode for LIBs without mixing with carbon black and polymer binder. MoS₂ nanoflakes (8.91 wt% of the composite sample) covering on CNF (MoS₂/CNF-B sample) plays the key role in activating the electrochemical properties of CNF, but dense MoS₂ nanoflakes (39.4 wt%) on CNF (MoS₂/CNF-A) seriously limit the electrochemical properties of CNF. At 0.1 and 1.0 A g⁻¹, MoS₂/CNF-B sample delivers 967.1 and 605.7 mA h g⁻¹, the capacities are almost twice as much as those of pure CNF. The initial columbic efficiency of MoS₂/CNF-B sample of 76.4% is much higher than that of pure CNF sample of 62.1%. Moreover, MoS₂/CNF-B sample presents no capacity decay till 100 cycles, and the cycled electrode at the 100th cycle still maintains a stable composite structure of MoS₂ nanoflakes covering on CNF.