Chemical Engineering Journal ( IF 15.1 ) Pub Date : 2020-10-27 , DOI: 10.1016/j.cej.2020.127502 Gaobo Lou , Gu Pei , Yitian Wu , Yingzhuo Lu , Yatao Wu , Xinqiang Zhu , Yajun Pang , Zhehong Shen , Qiang Wu , Shenyuan Fu , Hao Chen
Low-cost, high-performance, and long-life cathode materials are highly desired for zinc ion hybrid supercapacitors (ZHSs). Here, an N, O co-doped two-dimensional (2D) carbon nanosheet material is successfully fabricated via a one-step combustion conversion of wood for the excellent usage as the cathode material in zinc-ion hybrid supercapacitors. This novel combustion conversion synthesis with Zn(NO3)2·6H2O as oxidizer and urea as fuel can easily achieve the carbonization, pore-forming, and heteroatom doping within a one-step process. More interestingly, the resulting N, O co-doped porous carbon owns relatively uniform 2D sheet structure and very high specific surface area (1248 m2 g–1), which can not only provide short electric/ionic transfer path plus optimized wettability and conductivity for high power output, but also offer abundant interfacial active sites as well as improved ion adsorption capacity for high energy storage. Benefiting from these advantages, the ZHS based on this N, O co-doped 2D carbon nanosheets exhibits a superior specific capacity of 111.0 mAh g–1 at 0.1 A g–1, high rate capability of 57.6% capacity retention at a 30-fold higher current, and attractive energy density of 109.5 Wh kg–1 at 225 W kg–1. More gratifyingly, it displays ultralong cycling life with 92.7% capacity reservation after 50,000 charge and discharge cycles. Moreover, a quasi-solid ZHS with N, O co-doped 2D carbon nanosheets coated on the carbon cloth as the cathode also displays satisfactory specific capacity (34.6 mAh g–1), impressive energy density (27.7 Wh kg–1), and nice flexibility.
中文翻译:
木材燃烧转化为N,O共掺杂的2D碳纳米片,用于锌离子混合超级电容器
锌离子混合超级电容器(ZHSs)迫切需要低成本,高性能和长寿命的阴极材料。在此,通过木材的一步燃烧转化成功地制造了N,O共掺杂的二维(2D)碳纳米片材料,以出色地用作锌离子混合超级电容器中的阴极材料。以Zn(NO 3)2 ·6H 2 O为氧化剂,以尿素为燃料的新型燃烧转化合成,可在一个步骤的过程中轻松实现碳化,成孔和杂原子掺杂。更有趣的是,所得的N,O共掺杂多孔碳具有相对均匀的2D片状结构和非常高的比表面积(1248 m 2 g –1),不仅可以提供短的电/离子传输路径,并为高功率输出提供最佳的润湿性和导电性,而且还提供了丰富的界面活性位以及提高的离子吸附能力以实现高能量存储。得益于这些优势,基于这种N,O共掺杂的2D碳纳米片的ZHS在0.1 A g – 1的条件下显示出111.0 mAh g –1的超高比容量,在30倍容量下的高倍率容量为57.6%更高的电流,以及在225 W kg –1时具有109.5 Wh kg –1的有吸引力的能量密度。更令人欣喜的是,它在经过50,000次充放电循环后显示出超长的循环寿命,并具有92.7%的容量保留率。此外,在碳布上作为阴极涂覆有N,O共掺杂的2D碳纳米片的准固态ZHS还显示出令人满意的比容量(34.6 mAh g –1),令人印象深刻的能量密度(27.7 Wh kg –1)和很好的灵活性。