High-Temperature-Endurable, Flexible Supercapacitors:
Performance and Degradation Mechanism
Qin, B (Qin, Bin)[ 1,2 ] ; Wang, XT (Wang,
Xueting)[ 1,2 ] ; Sui, D (Sui, Dong)[ 1,2 ] ; Zhang, TF (Zhang,
Tengfei)[ 1,2 ] ; Zhang, M (Zhang, Miao)[ 1,2 ] ; Sun, ZH (Sun, Zhenhe)[ 1,2 ] ; Ge, Z (Ge, Zhen)[ 1,2 ] ; Xie, YQ (Xie, Yuqing)[ 1,2 ] ; Zhou, Y (Zhou, Ying)[ 1,2 ] ; Ren, YX (Ren, Yuxin)[ 1,2 ] ; Han, Y (Han,
Yu)[1,2 ] ; Ma, YF (Ma,
Yanfeng)[ 1,2 ] ; Chen, YS (Chen,
Yongsheng)[ 1,2 ]
ENERGY
TECHNOLOGY, 2018, 6(1): 161-170 特刊: SI
DOI: 10.1002/ente.201700368
WOS:000419906800019
Abstract
Current
state-of-the-art supercapacitors all have a limited operational temperature,
and thus, extension of the temperature range is in high demand. In this work,
high-temperature-endurable, flexible supercapacitors were fabricated by a very
simple method and by using commercially available, low-cost materials. The
device could be operated efficiently at 120 degrees C, and even after 10 000
cycles at an operation voltage of 2.5 V, approximately 75% of its capacitance
was retained. Furthermore, its performance remained essentially unchanged even
under high bending conditions. Cyclic voltammetry, electrochemical impedance
spectroscopy, scanning electron microscopy, energy-dispersive X-ray
spectroscopy, and X-ray photoelectron spectroscopy revealed that there were
three factors causing capacitance fading and an increase in the internal
resistance. The first one was fusion of the separator during high-temperature
electrochemical charging/discharging, which led to an increase in the internal
resistance. The second factor was decomposition of the separator, which
resulted in the accumulation of deposits on the surfaces of the positive and
negative electrodes. The third factor was that possible physical separation of
the active materials on the positive electrode from the current collector led
to a drastic increase in internal resistance.
