How deformation affects the performance of flexible supercapacitors: modeling study of Mo2C MXene natural rubber system

Research Overview: A study published in the Journal of Applied Polymer Science established an electrochemical mechanical coupled finite element framework using COMSOL Multiphysics, and systematically analyzed Mo2C MXene//natural rubber//Mo2C MXene symmetric flexible supercapacitors. This model integrates secondary current distribution, Nernst Planck ion transport, Butler Volmer dynamics, and hyperelastic structure model, aiming to reveal the mechanism of mechanical deformation on the ion transport and electrochemical performance of the device. In this device structure, the electrode is made of Mo2C MXene material and natural rubber is used as the diaphragm, balancing mechanical flexibility and electrochemical stability. The natural rubber diaphragm is immersed in 1 M KOH electrolyte, and the working potential window of the device is 0-0.6 V. This window is determined by three electrode simulation of Mo2C MXene electrode in 1 M KOH with Ag/AgCl as a reference.

Key Data and Performance

Simulation results show that under non bending conditions, when the current density is 1 A g-1, the specific capacitance of the device is 12.50 F g-1, the energy density is 0.625 Wh kg-1, and the power density is 150 W kg-1.

. Structural analysis shows that deformation can be ignored, and von Mises stress verifies the mechanical reliability of the structure. Under bending conditions, symmetric flexible supercapacitors exhibit changes in ion diffusion paths caused by deformation, resulting in a decrease in specific capacitance to 11.25 F g − 1, an energy density to 0.5625 Wh kg − 1, and a power density maintained at 150 W kg − 1 (1 A g − 1). This result indicates that mechanical deformation can have a quantifiable impact on electrochemical performance by altering the ion transport pathway.

Inspiration for polymer additives and rubber industry

Although this study focuses on flexible energy storage devices as the application scenario, the performance of its core material – natural rubber as a diaphragm – is closely related to the rubber formula design.

. In the tire and rubber industry, the mechanical flexibility and chemical stability of natural rubber are also key indicators. The hyperelastic structure model and electrochemical mechanical coupling method used in the study provide a valuable analytical approach for understanding the performance evolution of rubber materials under dynamic deformation conditions. From the perspective of rubber additives, the long-term stability, ion transport efficiency, and structural integrity of natural rubber membranes in electrolytes under repeated bending are closely related to the selection of vulcanization systems, anti-aging agents, and antioxidants. Although the study did not directly involve the formulation of additives, the deformation performance correlation mechanism revealed suggests that the dispersion state and sulfurization network structure of reinforcing fillers (such as white carbon black) may affect ion diffusion pathways and mechanical response in the development of rubber based flexible functional materials. In addition, this modeling framework can provide methodological references for predicting the performance of rubber products under dynamic working conditions, which has indirect enlightening significance for tire structure design and rubber aging research. The research author points out that this work provides a predictive framework for understanding performance trade-offs and can be used to guide the design of mechanically compliant polymer based energy storage devices. For the rubber industry, this interdisciplinary approach demonstrates the potential of natural rubber in functional applications, and also suggests that rubber formulation design needs to comprehensively consider the coupling effect of mechanical behavior and transmission performance.

Information source:Deformation‐Induced Electrochemical Performance of Mo2C MXene‐Natural Rubber Flexible Supercapacitor， Organized by Herun Chemical.