物理化学学报 >> 2025, Vol. 41 >> Issue (10): 100114.doi: 10.1016/j.actphy.2025.100114

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基于选择性化学刻蚀的低缺陷炭导电网络原位构筑及其对活性炭比表面积与导电性的协同增强

张晶1,†, 张苏1,*,†(), 李齐齐1, 纪麟肯2, 李禹彤3, 任宇康1, 臧小蓓1, 曹宁1, 胡涵4,*(), 梁鹏5,*(), 范壮军1   

  1. 1 中国石油大学(华东)材料科学与工程学院, 山东省智能能源材料重点实验室, 山东 青岛 266580
    2 青岛华世洁新材料科技集团股份有限公司, 山东 青岛 266510
    3 中国石油大学(华东)新能源学院, 山东 青岛 266580
    4 中国石油大学(华东)化学化工学院, 山东 青岛 266580
    5 山东科技大学化学与生物工程学院, 山东 青岛 266590
  • 收稿日期:2025-04-10 修回日期:2025-06-02 录用日期:2025-06-10 发布日期:2025-09-29
  • 通讯作者: Email: suzhangs@163.com (张苏)hhu@upc.edu.cn (胡涵)liangpeng202@hotmail.com (梁鹏)
  • 作者简介:

    †These authors contributed equally to this work.

  • 基金资助:
    国家自然科学基金(52062046); 国家自然科学基金(52302336); 国家自然科学基金(22179145); 山东省泰山学者项目(tsqn202306131); 山东省泰山学者项目(tsqn202312123); 山东省自然科学基金重点基础研究项目(ZR2019ZD51)

Integrating high surface area and electric conductivity in activated carbon by in situ formation of the less-defective carbon network during selective chemical etching

Jing Zhang1, Su Zhang1,*(), Qiqi Li1, Linken Ji2, Yutong Li3, Yukang Ren1, Xiaobei Zang1, Ning Cao1, Han Hu4,*(), Peng Liang5,*(), Zhuangjun Fan1   

  1. 1 Shandong Key Laboratory of Intelligent Energy Materials, School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong Province, China
    2 Qingdao Huashijie Environment Technology Co., Ltd., Qingdao 266510, Shandong Province, China
    3 College of New Energy, China University of Petroleum (East China), Qingdao 266580, Shandong Province, China
    4 College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong Province, China
    5 College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, Shandong Province, China
  • Received:2025-04-10 Revised:2025-06-02 Accepted:2025-06-10 Published:2025-09-29
  • Contact: Email: suzhangs@163.com (Su Zhang)hhu@upc.edu.cn (Han Hu)liangpeng202@hotmail.com (Peng Liang)
  • Supported by:
    the National Natural Science Foundation of China(52062046); the National Natural Science Foundation of China(52302336); the National Natural Science Foundation of China(22179145); the Taishan Scholar Project of Shandong Province(tsqn202306131); the Taishan Scholar Project of Shandong Province(tsqn202312123); the Key Basic Research Projects of Natural Science Foundation of Shandong province(ZR2019ZD51)

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摘要：

导电性是影响活性炭的电化学性能的重要因素，但活性炭发达的孔隙结构通常会破坏连续导电网络。本研究以沥青/聚丙烯腈(PAN)混合前驱体为原料，提出一种简单的选择性化学蚀刻策略制备兼具高比表面积与高导电性的活性炭。研究发现，PAN衍生炭包含无定形与结晶炭；在活化过程中，高反应活性的无定形炭被优先刻蚀，促使低缺陷炭骨架原位重构为连续导电网络。优化样品的比表面积达2773 m2·g−1，电导率提升了2.6倍(912 S·m−1)，性能优于大多数活性炭。此外，沥青和PAN分子之间通过预氧化产生的强交联效应使制备的活性炭的产率(58%)显著高于纯沥青基活性炭(34%)。组装的对称超级电容器在10 mg·cm−2高负载量下仍表现出优异的面电容(1 A·g−1时为2.8 F·cm−2)、良好的倍率性能(50 A·g−¹时电容保持率为41%)、高的能量密度(10.9 Wh·kg−1)及卓越的循环稳定性(50000次循环后容量无衰减)，本工作显示了高导电活性炭在实际应用中的巨大潜力，为先进储能器件用导电活性炭的制备提供了新思路。

关键词: 活性炭, 导电性, 比表面积, 超级电容器, 化学刻蚀

Abstract:

Activated carbons are widely used as the electrode material for supercapacitors owing to its large surface area, good electric conductivity, and outstanding electrochemical stability. Improving the electric conductivity of activated carbon is crucial for promoting its electrochemical energy storage, but hard to achieve because well-developed pores usually break the continuous conductive network. To solve this problem, researchers have developed several methods, such as selection of highly-conjugated carbon precursors, high-temperature post-treatment, compositing with highly conductive nanocarbons, and local catalytic graphitization. However, these methods generally suffer from high cost, low efficiency, and sacrifice of specific surface area. Herein, we propose a selective chemical etching strategy to prepare activated carbon with both high surface area and electric conductivity using a mixture of pitch and polyacrylonitrile (PAN) as the precursor. Through systematic investigation of the activation behavior of pure pitch, pure PAN, and the composite precursors, we demonstrate that the PAN-derived carbon contains amorphous and crystallized components. During activation, the amorphous carbon is primarily etched away due to its high reactivity, leading to the in-situ formation of less-defective carbon as the entire conductive network. The optimized sample shows a surface area of 2773 m2·g−1 and 2.6 times increased electric conductivity of 912 S·m−1, outperforming most of the reported activated carbons. Furthermore, the strong cross-linking between pitch and PAN molecules through pre-oxidation leads to a higher activated carbon yield of 58% than the pure pitch-derived activated carbon (34%). The optimized cross-linking structure also allows the activator K+ to be adsorbed more easily in the carbon precursor, which enhances the activation efficiency. As a result, the embedded PAN simultaneously construct conductive network and promote activation efficiency, leading to the integration of high electric conductivity and surface area of the activated carbon. For aqueous supercapacitor application, at the high electrode mass loading of 10 mg·cm−2, the optimized material shows remarkable areal capacitance (2.8 F·cm−2 at 1 A·g−1) and good rate performance (41% retention at 50 A·g−1). The corresponding device shows high energy densities (10.9 Wh·kg−1) and remarkable cycle stability (100% retention after 50000 cycles). The reason is that good electric conductivity enables high surface area utilization, significantly improved electric double-layer formation and ion transport kinetics. This work demonstrates the significant potential of highly conductive activated carbon for practical applications, and provides novel insights into the design of conductive activated carbon for advanced energy storage.

Key words: Activated carbon, Electric conductivity, Surface area, Supercapacitor, Chemical etching