Related Experiment Video
Updated: Jun 18, 2026

Solid-state Graft Copolymer Electrolytes for Lithium Battery Applications
Published on: August 12, 2013
Ionic ingress and charge-neutralization phenomena of conducting-polymer films
Saptarshi Majumdar1, Paratha S Ray, Kajari Kargupta
1Tata Research Development & Design Centre, Pune, India.
Abstract:
Ionic ingress and diffusion through a conducting-polymer (CP) film containing embedded charges under potential and concentration gradients is studied. Electroneutrality, a common assumption in modeling of similar systems, is not justified in this case or similar diffusion-limited processes, as the timescale of ionic diffusion in the solid matrix is quite large. Counter ions therefore cannot move instantaneously for effective neutralization of excess charges. Poisson-Nernst-Planck (PNP) equations have to be solved for such cases without any simplifying assumption. Analytical solution shows the existence of a charge boundary layer, which limits and strongly influences the ionic flux. A general numerical method for solution is also developed for the dynamic modeling, analysis, and design of these types of systems. The numerical results are validated by comparison with analytical solutions as well as with some experimental results available in the literature. With this modeling framework, the basic features of controlled release of molecules across a CP film under an applied electrical potential can be explained quantitatively.
Related Concept Videos
The Electrical Double Layer
Charging Conductors By Induction
Generally, conductors like metals do not allow any excess charge to be present on them. Any excess charge added to metals easily flows away, for example, when a metal is placed on the Earth. This process is called earthing.
However, conductors can be charged by a process called induction. For example, consider charging a...
Electrochemical Systems
Debye–Huckel–Onsager Conductance Equation
Processes at Electrodes
Dielectric Polarization in a Capacitor

