碳材料在电化学储能中的应用

电化学储能材料是电化学储能器件发展及性能提高的关键之一. 碳材料在各种电化学储能体系中都起到了极为重要的作用,特别是近期出现的各类新型碳材料为电化学储能的发展带来了新动力,并展现了广阔的应用前景. 本文综述了碳材料,特别是以碳纳米管和石墨烯为代表的纳米碳材料,在典型电化学储能器件（锂离子/钠离子电池、超级电容器和锂硫电池等）、柔性电化学储能和电化学催化等领域的研究进展,并对碳材料在这些领域的应用前景进行了展望.     

泡沫状二维复合材料的合成及超级电容器性能

利用蔗糖和乙醇作为碳源,以氯化镍高温还原形成的镍颗粒作为模板,制备了泡沫状石墨烯多孔材料。 继而以其作为载体,通过浸渍和高温热解法制备了泡沫状MoS₂/石墨烯二维复合材料。 通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉曼光谱、X射线衍射(XRD)等技术手段研究了复合材料的形貌、组成和结构。 循环伏安、恒流充放电和循环寿命测试均表明,该材料具有良好的超级电容器性能,质量比电容达203.5 F/g,面积比电容达280 mF/cm²,5000次恒流充放电循环后的电容保持率约80%。     

Ice/Salt-Assisted Synthesis of Ultrathin Two-Dimensional Micro/Mesoporous Iron and Nitrogen Co-Doped Carbon as an Efficient Electrocatalyst for Oxygen Reduction

An ice/salt-assisted strategy has been developed to achieve the green and efficient synthesis of ultrathin two-dimensional (2D) micro/mesoporous carbon nanosheets (CNS) with the dominant active moieties of Fe−N₄ (Fe-N-CNS) as high-performance electrocatalysts for the oxygen reduction reaction (ORR). The strategy involves freeze-drying a mixture of iron porphyrin and KCl salt using ice as template followed by a confined pyrolysis with KCl as an independent sealed nanoreactor to facilitate the formation of 2D carbon nanosheets, N incorporation, and porosity creation. The well-defined assembly of ultrathin 2D carbon nanosheets ensures high utilization of D1 and D3 Fe−N₄ active sites, and effectively promotes the mass transport of ORR reactants by virtue of the pronounced mesoporous structure. The resulting Fe-N-CNS electrocatalyst was shown to exhibit superior ORR activity, better electrochemical durability, and methanol tolerance towards ORR in alkaline electrolyte relative to the commercial Pt/C electrocatalyst.     

ZIF-67衍生的Ag/Co@NC材料及其氧还原性能的研究

氮掺杂的多孔碳材料可作为氧还原反应的催化剂,本文借助ZIF-67富氮多孔的特殊结构,采用湿式逐步还原法将Ag嵌入ZIF-67孔腔内,然后在Ar中碳化成功地制备了Ag/Co双金属嵌入的氮掺杂的多孔碳复合材料（Ag/Co@NC）作为氧还原反应的催化剂. 为了证明Ag的突出作用,同时在Ar中碳化了ZIF-67制备了Co嵌入的氮掺杂的多孔碳材料（Co@NC）. 利用扫描电子显微镜、透射电子显微镜、X射线衍射、X射线光电子能谱以及比表面积分析对材料的显微形貌、物相组成、结构进行分析,采用循环伏安和线性扫描极化曲线对材料的氧还原催化活性和催化稳定性进行研究. 结果表明,Ag的嵌入未改变ZIF-67的晶体结构,但是大大提高了材料的氧还原催化活性. Ag/Co@NC材料的半波电位和起始电位均高于Co@NC材料,且其在1000次循环伏安测试前后的半波电位变化仅为30 mV,显示出很好的催化稳定性和甲醇耐受性,可作为燃料电池和金属-空气电池的阴极催化剂.     

壳聚糖/硝酸铁凝胶制备铁氮掺杂多孔碳片作为高效氧还原电催化剂的研究

以壳聚糖/硝酸铁凝胶为前躯体,实现了含氮高分子与金属盐的均匀混合,将凝胶冷冻干燥处理后,经过热处理和酸刻蚀得到了成分及微结构更加均匀的铁氮掺杂多孔碳片. 铁氮掺杂多孔碳片与商业铂碳相比,具有更高的起始电位,半波电位和优秀的循环性能,在碱性燃料电池的测试中实现了更高的功率密度. 铁氮掺杂多孔碳片出色的氧还原电催化性能归因于铁在壳聚糖中的原子级分散所导致的均匀分布的铁氮碳催化活性位,大的比表面积和均匀的孔道分布.     

Microporous Carbon Nanofibers Derived from Poly(acrylonitrile-co-acrylic acid) for High-Performance Supercapacitors

Carbon nanofiber (CNF)-based supercapacitors have promising applications in the field of energy storage. It is desirable, but remains challenging, to develop CNF electrode materials with large specific surface area (SSA), high specific capacitance (SC), and high power density, as well as excellent cycling stability and high reliability. Herein, acrylonitrile–acrylic acid copolymer P(AN-co-AA) was synthesized for the preparation of nitrogen-doped microporous CNFs. Thermal degradation of the AA segment leads to the formation of micropores that are distributed not only on the CNF surface, but also inside the material. The microporous structure and nitrogen content can be manipulated at the molecular level by adjusting the weight ratio between AN and AA, and the SSA and SC could reach as high as 1099 m² g⁻¹ and 156 F g⁻¹, respectively. After KOH activation, the activated CNFs have an extremely high SSA of 2117 m² g⁻¹ and SC of 320 F g⁻¹, which are among the highest values ever reported for electric double-layer supercapacitors with an alkaline electrolyte. Furthermore, the capacitance retention, which can be maintained at 99 % even after 16 000 cyclic tests, reveals outstanding durability and repeatability.     

ZIF67衍生硫化钴/多孔碳复合催化剂的制备及其电催化性能

采用离子交换法与热处理相结合的方法,以ZIF67为前驱体,硫代乙酰胺为硫源,制备出硫化钴/多孔碳(CoS/C)复合催化材料,并探讨了硫化时间对复合催化剂的形貌、结构及其氧还原(ORR)性能的影响。采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、N2吸附-脱附测定仪、X射线光电子能谱分析(XPS)、拉曼光谱仪(Raman)和旋转圆盘电极(RDE)技术表征催化剂的物理特征和电催化性能。研究结果显示,在碱性条件下该复合催化剂具有与20%(w/w)的商业Pt/C催化剂相媲美的ORR活性,其半波电位仅比Pt/C催化剂低31 mV。随着硫化时间的增加,硫化钴颗粒逐渐增大,催化剂中碳材料的无序程度出现先减小后增大的趋势。在硫化时间为10 min时,复合催化剂在0.1 mol·L-1KOH中表现出良好的电催化活性,且在ORR过程中复合催化剂的平均转移电子数可达到3.72,接近于4,说明氧气在该催化剂表面发生的是四电子转移过程。     

Facile Synthesis of Nitrogen‐Containing Mesoporous Carbon for High‐Performance Energy Storage Applications

Porous carbon with high specific surface area (SSA), a reasonable pore size distribution, and modified surface chemistry is highly desirable for application in energy storage devices. Herein, we report the synthesis of nitrogen‐containing mesoporous carbon with high SSA (1390 m² g^?1), a suitable pore size distribution (1.5–8.1 nm), and a nitrogen content of 4.7 wt % through a facile one‐step self‐assembly process. Owing to its unique physical characteristics and nitrogen doping, this material demonstrates great promise for application in both supercapacitors and encapsulating sulfur as a superior cathode material for lithium–sulfur batteries. When deployed as a supercapacitor electrode, it exhibited a high specific capacitance of 238.4 F g^?1 at 1 A g^?1 and an excellent rate capability (180 F g^?1, 10 A g^?1). Furthermore, when an NMC/S electrode was evaluated as the cathode material for lithium–sulfur batteries, it showed a high initial discharge capacity of 1143.6 mA h g^?1 at 837.5 mA g^?1 and an extraordinary cycling stability with 70.3 % capacity retention after 100 cycles.     

High‐Yield Electrosynthesis of Hydrogen Peroxide from Oxygen Reduction by Hierarchically Porous Carbon

H₂O₂ production by electroreduction of O₂ is an attractive alternative to the current anthraquinone process, which is highly desirable for chemical industries and environmental remediation. However, it remains a great challenge to develop cost‐effective electrocatalysts for H₂O₂ synthesis. Here, hierarchically porous carbon (HPC) was proposed for the electrosynthesis of H₂O₂ from O₂ reduction. It exhibited high activity for O₂ reduction and good H₂O₂ selectivity (95.0–70.2 %, most of them >90.0 % at pH 1–4 and >80.0 % at pH 7). High‐yield H₂O₂ generation has been achieved on HPC with H₂O₂ concentrations of 222.6–62.0 mmol L^?1 (2.5 h) and corresponding H₂O₂ production rates of 395.7–110.2 mmol h^?1 g^?1 at pH 1–7 and ?0.5 V. Moreover, HPC was energy‐efficient for H₂O₂ production with current efficiency of 81.8–70.8 %. The exceptional performance of HPC for electrosynthesis of H₂O₂ could be attributed to its high content of sp³‐C and defects, large surface area and fast mass transfer.     

ZIF‐8 Derived Graphene‐Based Nitrogen‐Doped Porous Carbon Sheets as Highly Efficient and Durable Oxygen Reduction Electrocatalysts

Nitrogen‐doped carbon (NC) materials have been proposed as next‐generation oxygen reduction reaction (ORR) catalysts to significantly improve scalability and reduce costs, but these alternatives usually exhibit low activity and/or gradual deactivation during use. Here, we develop new 2D sandwich‐like zeolitic imidazolate framework (ZIF) derived graphene‐based nitrogen‐doped porous carbon sheets (GNPCSs) obtained by in situ growing ZIF on graphene oxide (GO). Compared to commercial Pt/C catalyst, the GNPCSs show comparable onset potential, higher current density, and especially an excellent tolerance to methanol and superior durability in the ORR. Those properties might be attributed to a synergistic effect between NC and graphene with regard to structure and composition. Furthermore, higher open‐circuit voltage and power density are obtained in direct methanol fuel cells.     

Polymer Waste Valorization into Advanced Carbon Nanomaterials for Potential Energy and Environment Applications

The rise in universal population and accompanying demands have directed toward an exponential surge in the generation of polymeric waste. The estimate predicts that world-wide plastic production will rise to ≈590 million metric tons by 2050, whereas 5000 million more tires will be routinely abandoned by 2030. Handling this waste and its detrimental consequences on the Earth's ecosystem and human health presents a significant challenge. Converting the wastes into carbon-based functional materials viz. activated carbon, graphene, and nanotubes is considered the most scientific and adaptable method. Herein, this world provides an overview of the various sources of polymeric wastes, modes of build-up, impact on the environment, and management approaches. Update on advances and novel modifications made in methodologies for converting diverse types of polymeric wastes into carbon nanomaterials over the last 5 years are given. A remarkable focus is made to comprehend the applications of polymeric waste-derived carbon nanomaterials (PWDCNMs) in the CO₂ capture, removal of heavy metal ions, supercapacitor-based energy storage and water splitting with an emphasis on the correlation between PWDCNMs' properties and their performances. This review offers insights into emerging developments in the upcycling of polymeric wastes and their applications in environment and energy.     

Synthesis of Sub‐nanometer Porous Carbon Film for Energy Storage

Carbon‐based supercapacitors are a kind of supercapacitors with very promising applications because of their low cost, good stability and adjustable properties. Simple and rapid syntheses of carbon materials with a high surface area and narrow pore size distribution are of great significance to practical applications of carbon‐based supercapacitors. Here we report a new strategy to synthesize sub‐nanometer porous carbon films (Snp‐CF) via a condensation reaction under mild conditions. Carbon films exhibit a narrow pore size distribution (6.6 Å) and high surface area (508 m² g^?1) after annealing at 700 °C. Snp‐CF‐700 displays a good specific capacity and excellent cycle performance (130 F g^?1 after 5000 cycles, 118 % of initial 110 F g^?1).     

Dual‐Template Pore Engineering of Whey Powder‐Derived Carbon as an Efficient Oxygen Reduction Reaction Electrocatalyst for Primary Zinc‐Air Battery

Cost‐effective and high‐performance electrocatalysts for oxygen reduction reactions (ORR) are needed for many energy storage and conversion devices. Here, we demonstrate that whey powder, a major by‐product in the dairy industry, can be used as a sustainable precursor to produce heteroatom doped carbon electrocatalysts for ORR. Rich N and S compounds in whey powders can generate abundant catalytic active sites. However, these sites are not easily accessible by reactants of ORR. A dual‐template method was used to create a hierarchically and interconnected porous structure with micropores created by ZnCl₂ and large mesopores generated by fumed SiO₂ particles. At the optimum mass ratio of whey power: ZnCl₂ : SiO₂ at 1 : 3 : 0.8, the resulting carbon material has a large specific surface area close to 2000 m² g^?1, containing 4.6 at.% of N with 39.7% as pyridinic N. This carbon material shows superior electrocatalytic activity for ORR, with an electron transfer number of 3.88 and a large kinetic limiting current density of 45.40 mA cm^?2. They were employed as ORR catalysts to assemble primary zinc‐air batteries, which deliver a power density of 84.1 mW cm^?2 and a specific capacity of 779.5 mAh g^?1, outperforming batteries constructed using a commercial Pt/C catalyst. Our findings open new opportunities to use an abundant biomaterial, whey powder, to create high‐value‐added carbon electrocatalysts for emerging energy applications.     

N,S-Co-Doped Porous Carbon Nanofiber Films Derived from Fullerenes (C60) as Efficient Electrocatalysts for Oxygen Reduction and a Zn–Air Battery

The development of highly efficient metal-free electrocatalysts for the oxygen reduction reaction (ORR) has attracted great attention for the creation of electrochemical energy devices. In this study, one-dimensional (1 D) fullerene nanofibers prepared from liquid–liquid interfacial precipitation are first fabricated into fullerene-derived carbon nanofiber films (FCNFs) through a simple filtration procedure. Then, pyrolysis of the FCNFs in the presence of ammonia and sulfur produces N- and S-co-doped porous carbon nanofiber films (N,S-PCNFs). As excellent metal-free electrocatalysts for the ORR, N,S-PCNFs exhibit remarkable catalytic activity, superior stability, and excellent methanol tolerance in both alkaline and acidic solution. Such a high ORR performance benefits from the robust porous nanofiber network structure with high concentrations of active N- and S- groups and abundant defects. Notably, upon practical use of N,S-PCNFs as catalysts in Zn-air batteries, a high power density and a large operating voltage are achieved, with a performance comparable to that of the commercial Pt/C catalyst. This work presents a facile strategy for the creation of a new class of energy nanomaterials based on fullerenes, demonstrating their practical uses in electrocatalytic ORR processes and Zn-air batteries.     

N-Doped Porous Carbon Derived from Solvent-Free Synthesis of Cross-Linked Triazine Polymers for Simultaneously Achieving CO2 Capture and Supercapacitors

It is highly desirable to design advanced heteroatomic doped porous carbon for wide application. Herein, N-doped porous carbon (NPC) was developed via the fabrication of high nitrogen cross-linked triazine polymers followed by pyrolysis and activation with controllable porous structure. The as-synthesized NPC at the pyrolysis temperature of 700 °C possessed rich nitrogen content (up to 11.51 %) and high specific surface area (1353 m² g⁻¹), which led to a high CO₂ adsorption capability at 5.67 mmol g⁻¹ at 298.15 K and 5 bar pressure and excellent stability. When the activation temperature was at 600 °C, such NPC exhibited a superior electrochemical performance as anode for supercapacitors with a specific capacitance of 158.8 and 113 F g⁻¹ in 6 M KOH at a current density of 1 and 10 A g⁻¹, respectively. Notably, it delivered an excellent stability with capacity retention of 97.4 % at 20 A g⁻¹after 6000 cycles.     

NiCo2S4 Materials for Supercapacitor Applications

Cobalt–nickel sulfide (NiCo₂S₄) shows extensive potential for innovative photoelectronic and energetic materials owing to distinctive physical and chemical properties. In this review, representative strategies for the fabrication and application of NiCo₂S₄ and composite nanostructures are outlined for supercapacitors, with the aim of promoting the development of NiCo₂S₄ and their composites in the supercapacitor field through an analysis and comparison of diverse nanostructures. A brief introduction into the structures, properties, and morphologies are presented. Further prospects and promising developments of the materials in the supercapacitor field are also proposed.     

Porous Nitrogen‐Doped Carbon Microspheres Derived from Microporous Polymeric Organic Frameworks for High Performance Electric Double‐Layer Capacitors

This research presents a simple and efficient method to synthesize porous nitrogen‐doped carbon microspheres (PNCM) by the carbonization of microporous poly(terephthalaldehyde‐pyrrole) organic frameworks (PtpOF). The common KOH activation process is used to tune the porous texture of the PNCM and produce an activated‐PNCM (A‐PNCM). The PNCM and A‐PNCM with specific surface area of 921 and 1303 m² g^?1, respectively, are demonstrated as promising candidates for EDLCs. At a current density of 0.5 A g^?1, the specific capacitances of the PNCM and A‐PNCM are 248 and 282 F g^?1, respectively. At the relatively high current density of 20 A g^?1, the capacitance remaining is 95 and 154 F g^?1, respectively. Capacity retention of the A‐PNCM is more than 92 % after 10 000 charge/discharge cycles at a current density of 2 A g^?1.     

Soft‐Templating Synthesis of N‐Doped Mesoporous Carbon Nanospheres for Enhanced Oxygen Reduction Reaction

The development of ordered mesoporous carbon materials with controllable structures and improved physicochemical properties by doping heteroatoms such as nitrogen into the carbon framework has attracted a lot of attention, especially in relation to energy storage and conversion. Herein, a series of nitrogen‐doped mesoporous carbon spheres (NMCs) was synthesized via a facile dual soft‐templating procedure by tuning the nitrogen content and carbonization temperature. Various physical and (electro)chemical properties of the NMCs have been comprehensively investigated to pave the way for a feasible design of nitrogen‐containing porous carbon materials. The optimized sample showed a favorable electrocatalytic activity as evidenced by a high kinetic current and positive onset potential for oxygen reduction reaction (ORR) due to its large surface area, high pore volume, good conductivity, and high nitrogen content, which make it a highly efficient ORR metal‐free catalyst in alkaline solutions.     

Carbon Nanotube@N‐Doped Mesoporous Carbon Composite Material for Supercapacitor Electrodes

Here, carbon nanotube@N‐doped mesoporous carbon (CNT@N‐PC) composites were synthesized by using resorcinol‐formaldehyde resin as carbon source, ionic liquids (ILs) as template, and nitrogen sources and tetraethyl orthosilicate (TEOS) as assistant agent. The use of ILs‐modified CNT with nitrogen and TEOS facilitated the generation of a richer mesoporous structure. The obtained CNT@N‐PC was composed of a CNT core and mesoporous carbon particles around it. CNT@N‐PC showed a 3D network structure like “dewy cobwebs” and had a high surface area of 857 m² g^?1, uniform pore size distribution (3.0 nm), and suitable N content (4.9 at.%). When used as supercapacitor electrode, the CNT@N‐PC exhibited a high specific capacitance (244 F g^?1 at 1 A g^?1), good rate capability and favorable capacitance retention (92.5 % capacitive retention after 5000 cycles), demonstrating the potential for application in high‐performance supercapacitors.     

氮掺杂石墨烯量子点/MOF衍生多孔碳纳米片构筑高性能超级电容器

首先采用溶液法在碳布上生长Co-MOF二维纳米片,通过高温退火和刻蚀后得到MOF衍生多孔碳纳米片。以Co-MOF衍生的多孔碳纳米片/碳布(CNS/CC)作为碳基骨架,采用电化学沉积法负载高活性氮掺杂石墨烯量子点(N-GQDs),制备得到分级多孔结构的N-GQD/CNS/CC复合材料。组装成自支撑且无粘结剂的N-GQD/CNS/CC电极,当电流密度为1 A·g~(-1)时,其比电容高达423 F·g~(-1)。通过储能机制和电容贡献机制的研究表明,在碳纤维上原位生长的具有高双电层电容的CNS和表面负载具有高赝电容的N-GQDs之间相互协同作用,使得N-GQD/CNS/CC电极具有高电容性能,是一种理想的超级电容器电极材料。电极材料的高导电、分级多孔结构有利于电子的传输和电解质离子的扩散,具有良好的动力学性能,能快速充放电和具有优异的倍率特性。将电极组装成对称型超级电容器,功率密度为250 W·kg~(-1)时对应的能量密度达到7.9 Wh·kg~(-1),且经过10 000次循环后电容保持率为91.2%,说明氮掺杂石墨烯量子点/MOF衍生多孔碳纳米片复合材料是一种电化学性能稳定的具有高电容性能的全碳电极材料。