TY - JOUR

T1 - Sterically Induced Enhancement in the Electrochemical Stability of Salen-Type Cathode Materials

AU - Novoselova, Julia V.

AU - Beletskii, Evgenii V.

AU - Lukyanov, Daniil A.

AU - Filippova, Sofia S.

AU - Rodionova, Uliana M.

AU - Sizov, Vladimir V.

AU - Alekseeva, Elena V.

AU - Levin, Oleg V.

PY - 2025/1/13

Y1 - 2025/1/13

N2 - This study investigates the electrochemical degradation mechanisms of nickel-salen (NiSalen) polymers, with a focus on improving the material's stability in supercapacitor applications. We analyzed the effects of steric hindrance near the nickel center by incorporating different bulky substituents into NiSalen complexes, aiming to mitigate water-induced degradation. Electrochemical performance was assessed using cyclic voltammetry, operando conductance, and impedance measurements, while X-ray photoelectron spectroscopy (XPS) provided insights into molecular degradation pathways. The results revealed that increased steric hindrance from methyl groups significantly reduced the degradation rate, particularly in water-containing electrolytes, by hindering water coordination to the Ni center. Among the studied polymers, the highly substituted poly[Ni(Saltmen)] exhibited superior stability with minimal capacity loss. Density functional theory (DFT) calculations further supported that steric protection around the Ni atom effectively lowers the probability of water coordination. These findings suggest that sterically enhanced NiSalen polymers may offer a promising path toward durable supercapacitor electrodes, highlighting the route of molecular engineering to enhance material stability.

AB - This study investigates the electrochemical degradation mechanisms of nickel-salen (NiSalen) polymers, with a focus on improving the material's stability in supercapacitor applications. We analyzed the effects of steric hindrance near the nickel center by incorporating different bulky substituents into NiSalen complexes, aiming to mitigate water-induced degradation. Electrochemical performance was assessed using cyclic voltammetry, operando conductance, and impedance measurements, while X-ray photoelectron spectroscopy (XPS) provided insights into molecular degradation pathways. The results revealed that increased steric hindrance from methyl groups significantly reduced the degradation rate, particularly in water-containing electrolytes, by hindering water coordination to the Ni center. Among the studied polymers, the highly substituted poly[Ni(Saltmen)] exhibited superior stability with minimal capacity loss. Density functional theory (DFT) calculations further supported that steric protection around the Ni atom effectively lowers the probability of water coordination. These findings suggest that sterically enhanced NiSalen polymers may offer a promising path toward durable supercapacitor electrodes, highlighting the route of molecular engineering to enhance material stability.

KW - X-ray photoelectron spectroscopy (XPS)

KW - cyclic voltammetry

KW - density functional theory (DFT)

KW - electrochemical stability

KW - impedance spectroscopy

KW - nickel–salen polymers

KW - operando conductance

KW - steric hindrance

KW - supercapacitors

KW - water-induced degradation

UR - https://www.mendeley.com/catalogue/4322941d-4c82-395a-b5af-e4935ff378ff/

U2 - 10.3390/polym17020178

DO - 10.3390/polym17020178

M3 - Article

C2 - 39861250

VL - 17

JO - Polymers

JF - Polymers

SN - 2073-4360

IS - 2

M1 - 178

ER -