TY - JOUR

T1 - Kinetic analysis of redox processes in Salen-type polymers at sub-zero temperatures

AU - Novoselova, Julia

AU - Ershov, Valentin

AU - Levin, Oleg

AU - Lukyanov, Daniil

AU - Ovchinnikova, Lina

AU - Li, Ruopeng

AU - Yang, Peixia

AU - Alekseeva, Elena

N1 - Publisher Copyright: © 2022 Elsevier B.V.

PY - 2022/10/15

Y1 - 2022/10/15

N2 - Batteries and supercapacitors are widely used in various types of portable electronic devices and electric vehicles. Typically, they retain energy and power density at room temperature and at temperatures up to +60° C. However, at sub-zero temperatures, the energy as well as the power density of the power sources dramatically decline due to the sluggish kinetics, mostly connected with solvation/desolvation processes. One of the approaches to solving the problem is using organic electrode materials, among which NiSalen-type polymers may be considered as one of the prospective. Here, we investigate the kinetic restrictions of the redox processes in such polymers at sub-zero temperatures. Temperature-dependent relationships of the kinetic parameters of charge/discharge of poly[Ni(Salen)], poly[Ni(CH3Salen)] and poly [Ni(CH3Saltmen)] were determined in electrolyte solutions based on acetonitrile and ethyl acetate with Et4NBF4, LiClO4 and LiTFSI salts. It was shown that injection of counter ions into the polymer film limits the redox processes, and the activation energy of the process depends on the film structure as well as electrolyte composition. Proper combination of the electrolyte and polymer ensures low-activation process of counter ion injection, which corresponds to the absence of desolvation stage. As a result, fast charge and discharge of such materials is possible at the temperatures as low as –40 °C.

AB - Batteries and supercapacitors are widely used in various types of portable electronic devices and electric vehicles. Typically, they retain energy and power density at room temperature and at temperatures up to +60° C. However, at sub-zero temperatures, the energy as well as the power density of the power sources dramatically decline due to the sluggish kinetics, mostly connected with solvation/desolvation processes. One of the approaches to solving the problem is using organic electrode materials, among which NiSalen-type polymers may be considered as one of the prospective. Here, we investigate the kinetic restrictions of the redox processes in such polymers at sub-zero temperatures. Temperature-dependent relationships of the kinetic parameters of charge/discharge of poly[Ni(Salen)], poly[Ni(CH3Salen)] and poly [Ni(CH3Saltmen)] were determined in electrolyte solutions based on acetonitrile and ethyl acetate with Et4NBF4, LiClO4 and LiTFSI salts. It was shown that injection of counter ions into the polymer film limits the redox processes, and the activation energy of the process depends on the film structure as well as electrolyte composition. Proper combination of the electrolyte and polymer ensures low-activation process of counter ion injection, which corresponds to the absence of desolvation stage. As a result, fast charge and discharge of such materials is possible at the temperatures as low as –40 °C.

KW - Activation energy

KW - Cyclic Voltammetry

KW - Low temperature electrode material

KW - Metal-salen-type polymers

KW - Reaction rate constant

UR - http://www.scopus.com/inward/record.url?scp=85138436777&partnerID=8YFLogxK

U2 - 10.1016/j.jelechem.2022.116823

DO - 10.1016/j.jelechem.2022.116823

M3 - Article

AN - SCOPUS:85138436777

VL - 923

JO - Journal of Electroanalytical Chemistry

JF - Journal of Electroanalytical Chemistry

SN - 1572-6657

M1 - 116823

ER -