生物质炭@MnO<sub>2</sub>基超级电容器电极材料研究进展

张亚林; 陈兴刚; 王梦倩; 任梦雅; 蔡艳青; 许莹

doi:10.13801/j.cnki.fhclxb.20221109.001

生物质炭@MnO₂基超级电容器电极材料研究进展

doi: 10.13801/j.cnki.fhclxb.20221109.001

华北理工大学　材料科学与工程学院，河北省无机非金属材料重点实验室，唐山 063021

基金项目: 河北省省属高校基本科研业务费研究项目(JST2022005)；华北理工大学大学生创新创业训练项目(T2022047)

详细信息

通讯作者:
蔡艳青，博士，副教授，硕士生导师，研究方向为储能材料、熔盐电化学、医用生物材料等　E-mail: caiyanqing126@126.com

中图分类号: TB332
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出版历程
- 收稿日期: 2022-09-20
- 修回日期: 2022-10-25
- 录用日期: 2022-10-29
- 网络出版日期: 2022-11-10
- 刊出日期: 2023-07-15

Research progress of biomass carbon@MnO₂-based electrode materials for supercapacitors

Hebei Provincial Key Laboratory of Inorganic Nonmetallic Materials, College of Materials Science and Engineering, North China University of Science and Technology, Tangshan 063210, China

Funds: Basic Research Funds of Hebei Provincial Universities (JST2022005); Innovation and Entrepreneurship Training Program for College Students of North China University of Science and Technology (T2022047)

摘要

摘要: 目的基于能源危机、环境污染等问题，开发新型的高性能储能装置至关重要，超级电容器因具有高比能量、稳定性好等优异性能而受到研究者青睐。具有发达的孔径、较高的活性比表面积，且资源廉价丰富的生物质炭和最有应用前途的赝电容材料MnO复合具有取长补短的作用。本文主要介绍了生物质炭的来源、特点及制备方法，并介绍了生物质炭与MnO的复合制备方法及生物质炭@MnO复合材料用于超级电容器的研究现状，最后展望了生物质炭@MnO基超级电容器的发展趋势。生物质炭研究进展：相较于煤炭、石油焦等不可再生资源日益短缺，生物质炭材料具有来源广、成本低和绿色环保等优点，其前驱体主要来源一般为植物(木材、香蕉皮、茶叶、稻壳、柚皮等)、动物粪便、微生物细菌等天然产物，经高温热解碳化得到衍生碳材料。生物质炭材料形成的多级孔道结构稳定性好，比表面积、孔道结构和表面的官能团会对电化学性能产生重要影响，在超级电容器中具有很大的优势和前景。目前，生物质多孔碳的制备方法较为常用是化学活化法。化学活化法中活化剂的选择是主要影响到生物质炭电化学的因素。常使用的活化剂有碱、氯化锌和磷酸。尽管生物质炭在超级电容器中已被广泛应用，但在制备工艺、储能特性等方面仍存在诸多限制。实现对生物质炭材料的比表面积、孔径分布、结构特征、导电性以及表面官能团的有效调控，可提高生物质炭材料在超级电容器中的电化学性能。制备：生物质炭是一种绿色环保的电极材料，且稳定性高，循环寿命高，但它制备的超级电容器能量密度小，不适合大规模使用。MnO是可以提高生物质炭比电容的过渡金属氧化物，可为超级电容器提供赝电容。因此，通常将生物质碳与MnO复合制备高性能电极材料。以生物质炭为基底材料，生物质炭与MnO之间形成化学键，在生物质炭表面上包覆一层MnO。分别阐述了几种生物质炭@MnO电极材料的制备方法及研究现状，研究较多的三种制备方法为原位化学共沉淀法、电沉积法和水热法。原位化学共沉淀法通常在油浴或水浴中进行的，这种复合方法操作简单，该复合方法利用高锰酸钾的强氧化性，在生物质碳的表面进行还原沉积，制备的复合材料呈核壳结构，生物质炭为核部分，MnO为壳部分。采用电沉积法复合生物质碳和MnO，复合效果主要取决于生物炭材料的结构。利用水热法将生物炭和MnO复合，是MnO在生物质碳上扩展的一种方法，复合上的MnO呈花状结构，这种特殊的花状MnO增大比表面积和增强生物质碳材料的导电性。展望：目前，超级电容器是最具有应用前景的储能器件之一，与锂离子电池相比，超级电容器的循环稳定性更高，更加安全环保。将生物质材料变废为宝，通过碳化、活化制备生物质炭材料，可被广泛用作超级电容器的电极材料。尽管生物质炭@MnO材料制备的超级电容器的优点是很多储能器件无法比拟的，如其使用寿命是普通电池的几百倍，但目前制备及应用还不成熟，不同的生物质炭材料的微观形貌、性能差异性很大，与MnO复合方式及机理也存在差异，因而生物质炭@MnO基复合材料用于超级电容器实用化详细数据库需进一步探索。此外，MnO在生物质炭的沉积速度不易控制，过快易导致产物的孔隙堵塞，需要进一步探索复合电极材料的稳定制备技术，使生物质炭@MnO结构设计合理化和功能化。因此，生物质炭@MnO基复合材料制备超级电容器距离实现大规模商业应用还有很长的路要走，研究开发性能优良、产率高、经济效益好的生物质炭@MnO电极材料。
- 生物质炭 /
- MnO₂ /
- 超级电容器 /
- 制备 /
- 研究进展
Abstract: Based on the problems of energy crisis and environmental pollution, it is very important to develop new high-performance energy storage devices. Supercapacitors are favored by researchers because of their high specific energy and good stability. Biomass carbon is obtained by pre-carbonization and activation of biomass materials, with developed pore size, high active specific surface area, and rich resources, which has good application prospects as a supercapacitor material. In order to meet the high specific capacity and high cycle stability of supercapacitors, the current effective method is to combine biomass carbon materials with pseudo capacitor materials. Transition metal oxide MnO₂ has become the most promising pseudocapacitor material due to its high theoretical specific capacitance, wide potential window, low cost and environmental friendliness. The research shows that the specific capacitance and energy density of the supercapacitor made of the composite material of biomass carbon and transition metal oxide are significantly improved. This paper mainly introduces the source, characteristics and preparation methods of biomass carbon, also introduces the composite methods of biomass carbon and MnO₂ and the research progress of biomass carbon@MnO₂ composite materials, and finally looks forward to the development trend of biomass carbon@MnO₂ based supercapacitors.
- biomass carbon /
- MnO₂ /
- supercapacitors /
- preparation /
- research progress

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图 1 钾单质插入碳层造孔机制图^[31]

Figure 1. Pore forming mechanism diagram of potassium inserted into carbon layer^[31]

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图 2 在5 A/g电流密度下木质素生物质炭电极(a)和木质素生物质炭和MnO₂复合材料电极(b)循环稳定性和库伦效率图^[41]

Figure 2. Cyclic stability and coulomb efficiency of lignin biochar electrode (a) and lignin biochar and MnO₂ composite electrode (b) at 5 A/g current density^[41]

WDB—Wood-derived biochar

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图 3 (a) 无复合MnO₂多孔碳复合材料；(b) 在油浴中复合1 h多孔碳@MnO₂；(c) 在油浴中复合3 h多孔碳@MnO₂；(d) 在油浴中复合8 h多孔碳@MnO₂；(e) 在油浴中复合9 h多孔碳@MnO₂；(f) 在油浴中复合15 h MnO₂@多孔碳^[42]

Figure 3. (a) No composite MnO₂ porous carbon composite; (b) Porous carbon@MnO₂ composite in oil bath for 1 h; (c) Porous carbon@MnO₂ composite in oil bath for 3 h; (d) Porous carbon@MnO₂ composite in oil bath for 8 h; (e) Porous carbon@MnO₂ composite in oil bath for 9 h; (f) Porous carbon@MnO₂ composite in oil bath for 15 h^[42]

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图 4 多孔碳@MnO₂的制作流程^[14]

Figure 4. Production process of porous carbon@MnO₂^[14]

HPC—Hierarchical porous carbon

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图 5 生物质碳预碳化及分级多孔碳和MnO₂复合过程中结构示意图^[14]

Figure 5. Schematic structural diagram of biomass carbon pre carbonization and hierarchical porous carbon and MnO₂ composite process^[14]

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图 6 制备不同玉米芯碳基底超级电容器示意图^[45]

Figure 6. Schematic diagram of preparing supercapacitors with different corn cob carbon substrates^[45]

CC—Corncob carbon; AC—Activated carbon; PVA—Polyvinyl alcohol; ASC—All-solid-state supercapacitor

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图 7 ((a), (b)) 沉积5 min活化生物质炭@MnO₂的SEM和HR-SEM图像；((c), (d)) 沉积2 h碳化的生物质炭@MnO₂的SEM和HR-SEM图像；((e), (f)) 沉积2 h碳化生物质炭@MnO₂ TEM和HR-TEM图像(插图：选定区域电子衍射)^[45]

Figure 7. ((a), (b)) SEM and HR-SEM images of 5 min activated biochar@MnO₂ deposited; ((c), (d)) SEM and HR-SEM images of deposited 2 h carbonized biomass carbon@MnO₂; ((e), (f)) TEM and HR-TEM images of deposited 2 h carbonized biomass carbon@MnO₂(Inset: Electron diffraction in selected areas)^[45]

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图 8 经过活化和只碳化的两种生物质碳表面电沉积MnO₂的示意图^[45]

Figure 8. Schematic diagram of MnO₂ electrodeposition on carbon surface of two kinds of biomass after activation and carbonization only^[45]

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图 9 ((a), (b)) KOH活化处理的多孔碳的SEM图像；(c) KOH活化处理的多孔碳的TEM图像；((d), (e)) 3 h水热复合多孔碳@MnO₂ SEM图像；(f) 3 h水热复合多孔碳@MnO₂的TEM图像；(g) 3 h水热复合多孔碳@MnO₂ EDS图像^[51]

Figure 9. ((a), (b)) SEM images of KOH activated porous carbon; (c) TEM image of KOH activated porous carbon; ((d), (e)) SEM images of 3 h hydrothermal composite MnO₂@porous carbon; (f) TEM image of 3 h hydrothermal composite porous carbon@MnO₂; (g) EDS diagram of 3 h hydrothermal composite porous carbon@MnO₂^[51]

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图 10 (a) 25 mV/s时EC、MnO₂和MnO₂/EC复合材料的CV曲线；(b) 0.5 A/g时EC、MnO₂和MnO₂/EC复合材料的恒流充放电曲线；(c) MnO₂/EC复合材料在10、25、50、75和100 mV/s下的CV曲线；(d) MnO₂/EC复合材料在0.5、1.0、2.0、5.0和10 A/g下的恒流充放电曲线；(e) 不同电流密度下EC、MnO₂和MnO₂/EC复合材料的比电容；(f) EC、MnO₂和MnO₂/EC的电化学阻抗谱^[52]

Figure 10. (a) CV curves of EC, MnO₂ and MnO₂/EC composites at 25 mV/s; (b) Galvanostatic charge/discharge curves of EC, MnO₂ and MnO₂/EC composites at 0.5 A/g; (c) CV curves of MnO₂/EC composites at 10, 25, 50, 75 and 100 mV/s; (d) Galvanostatic charge/discharge curves of MnO₂/EC composites at 0.5, 1.0, 2.0, 5.0 and 10 A/g; (e) Specific capacitance of EC, MnO₂ and MnO₂/EC composites at different current densities; (f) Electrochemical impedance spectroscopy of EC, MnO₂ and MnO₂/EC^[52]

EC—Eggplant carbon; Z'—Real part of impedance; Z"—Imaginary part of impedance

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表 1 木材、香蕉皮、茶叶、稻壳、柚皮、塔松、水稻秸秆的微观结构和电化学性能^[28]

Table 1. Microstructure and electrochemical properties of wood, banana peel, tea, rice husk, pomelo peel, tarzon and rice straw^[28]

Biomass carbon precursor	Biomass carbon morphology	Electrochemical performance







Note: PC—Direct pyrolysis of wood chips; RC—PC delignified treatment; TARC—Carbonized wood chips; TARC-N—TARC treated twice in N₂; KB—KHCO₃; AC—Porous carbon; X—KHCO₃(KOH)/HC mass radio; HC—Hydrothermal carbon.

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