接枝尾端荷电聚电解质对超级电容器充电动力学特性影响研究  

Study of the effect of grafted end-charged polyelectrolyte on charging dynamics of supercapacitors

作　　者：刘梦 张华杰 信杨 吴鹏 LIU Meng;ZHANG Huajie;XIN Yang;WU Peng(School of Energy and Power Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;School of Energy and Power Engineering,Central China University of Science and Technology,Wuhan 430074,China;State Key Laboratory of Wind and Solar Energy,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]内蒙古工业大学能源与动力工程学院,呼和浩特010051 [2]华中科技大学能源与动力工程学院,武汉430074 [3]内蒙古工业大学风能太阳能利用技术教育部重点实验室,呼和浩特010051

出　　处：《内蒙古工业大学学报（自然科学版）》2024年第6期554-560,共7页Journal of Inner Mongolia University of Technology：Natural Science Edition

基　　金：内蒙古自治区自然科学基金项目(2023QN5002);内蒙古自治区直属高校基本科研业务费项目(JY20220136)。

摘　　要：超级电容器系统接枝聚电解质对改善其性能有重要应用价值,例如可降低接触电阻、提升电容。通过求解包含水力学模型的连续性方程,研究了孔径为3 nm的纳米孔在接枝尾端荷电聚电解质情况下的充电动力学特性,研究发现聚电解质虽然会增大电荷存储,但较短的聚电解质会降低纳米孔内电解液对流强度,进而降低超级电容器功率,这是由于聚电解质的链长及表面电荷密度会改变反离子分布位置及数量,从而改变纳米孔内电解液对流驱动力的位置及大小。另外,还研究了电解液的对流作用对电荷存储机制的影响,研究发现纳米孔中心处的电解液流动增强了共离子解吸,促进了电荷存储机制从反离子吸附占主导向离子交换占主导转变。Supercapacitor system grafted polyelectrolytes has important application value to improve its performance,such as reducing contact resistance and increasing capacitance.In this work,the charge dynamics of 3 nm nanopore with grafted end charged polyelectrolytes were studied by solving a continuity equations including hydrodynamic model.It is found that although polyelectrolytes increase the charge storage,the shorter polyelectrolytes decrease the strength of convection of the electrolyte in the nanopore,thus reducing the power of supercapacitors.This is because the chain length and surface charge density of polyelectrolytes will change the distribution position and quantity of counter ions,thus changing the position and magnitude of the driving force of electrolyte convection in the nanopore.In addition,the effect of electrolyte convection on charge storage mechanism is also studied.It was found that the convection at the center of the nanopore,enhanced the co-ion desorption,and promoted the charge storage mechanism to change from dominated by counter-ion adsorption to dominated by ion exchange.

关 键 词：超级电容器 分子动力学模拟 纳米多孔电极 充电动力学 聚电解质 

分 类 号：O643.1[理学—物理化学] TM53[理学—化学]