Effects of Polyelectrolyte Surface Coating on the Energy Storage Performance in Supercapacitors

作者：Qiu, Genlong; Qiu, Qiyuan; Qing, Leying; Zhou, Jingmin; Xu, Xiaofei^*; Zhao, Shuangliang^*

来源：Journal of Physical Chemistry C, 2022, 126(19): 8218-8226.

DOI：10.1021/acs.jpcc.1c10956

• CARBON NANOTUBE COMPOSITE
• BLUE ENERGY
• DENSITY
• ELECTROLYTE

Polymer electrode materials are critical componentsto achieve the excellent energy storage performance (ESP) ofsupercapacitors, while the underlying microscopic mechanism bywhich the polymer structure on the electrode surface affects theenergy storage remains unclear. Herein, we explore the effects of apolyelectrolyte (PE) coating on the ESP of supercapacitors byusing the polymer density functional theory. The ESP isdetermined by the adsorption of free ions at the electrode surface,which is jointly affected by the interactions from both the chargedsurface and the anchored PE chains. Once the PE chains carry likecharges as the electrode, the energy density can be significantlypromoted by two orders of magnitude. However, if the PE chains carry opposite charges to the electrode, the energy density can besuppressed. The effect of PE coating on the capacitance is similar to that on the energy density if the surface voltage isfixed duringthe operation, and otherwise, if the surface charge density isfixed, the effect on the capacitance is opposite to that on the energydensity. This work provides a microscopic understanding of the complex polyelectrolyte coating'seffects on the ESP insupercapacitors.

• 单位
  华东理工大学; 广西大学