Zuo Wenhua, Wang Chong, Li Yuanyuan, Liu Jinping
Institute of Nanoscience and Nanotechnology, Department of Physics, Central China Normal University, Wuhan 430079, Hubei, P.R. China.
School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
Sci Rep. 2015 Jan 14;5:7780. doi: 10.1038/srep07780.
Hybrid supercapacitor (HSC), which typically consists of a Li-ion battery electrode and an electric double-layer supercapacitor electrode, has been extensively investigated for large-scale applications such as hybrid electric vehicles, etc. Its application potential for thin-film downsized energy storage systems that always prefer high volumetric energy/power densities, however, has not yet been explored. Herein, as a case study, we develop an entirely binder-free HSC by using multiwalled carbon nanotube (MWCNT) network film as the cathode and Li(4)Ti(5)O(12) (LTO) nanowire array as the anode and study the volumetric energy storage capability. Both the electrode materials are grown directly on carbon cloth current collector, ensuring robust mechanical/electrical contacts and flexibility. Our 3 V HSC device exhibits maximum volumetric energy density of 4.38 mWh cm(-3), much superior to those of previous supercapacitors based on thin-film electrodes fabricated directly on carbon cloth and even comparable to the commercial thin-film lithium battery. It also has volumetric power densities comparable to that of the commercial 5.5 V/100 mF supercapacitor (can be operated within 3 s) and has excellent cycling stability (92% retention after 3000 cycles). The concept of utilizing binder-free electrodes to construct HSC for thin-film energy storage may be readily extended to other HSC electrode systems.
混合超级电容器（HSC）通常由锂离子电池电极和双电层超级电容器电极组成，已被广泛研究用于混合动力汽车等大规模应用。然而，其在始终偏好高体积能量/功率密度的薄膜小型化储能系统中的应用潜力尚未得到探索。在此，作为一个案例研究，我们通过使用多壁碳纳米管（MWCNT）网络薄膜作为阴极和Li(4)Ti(5)O(12)（LTO）纳米线阵列作为阳极，开发了一种完全无粘结剂的HSC，并研究了其体积储能能力。两种电极材料都直接生长在碳布集流体上，确保了牢固的机械/电气接触和柔韧性。我们的3V HSC器件表现出约4.38 mWh cm(-3)的最大体积能量密度，远优于以前基于直接在碳布上制造的薄膜电极的超级电容器，甚至与商用薄膜锂电池相当。它还具有与商用5.5V/100mF超级电容器相当的体积功率密度（可在3秒内运行），并具有出色的循环稳定性（3000次循环后保留率约为92%）。利用无粘结剂电极构建用于薄膜储能的HSC的概念可能很容易扩展到其他HSC电极系统。
