One of the main limitations of batteries is their degrading performance. Researchers base their studies on this process in their attempts to develop promising new designs. What was lacking, however, was a functional theoretical model that can describe battery degradation and therefore speed up the development of new, more efficient batteries.
At the Massachusetts Institute of Technology in Cambridge, Matthew Pinson and Martin Bazant decided to take on this job. They developed a simple model that shows how charging and recharging batteries affects the movement of ions from one part of the battery to another. If ions enter lattices where they are not meant to be present, they destroy their structure and therefore reduce the lifespan of the battery.
This is the case with Li-ion batteries. During charging, ions enter a silicon lattice causing it to expand, which reduces the performance and eventually causes the battery to stop working.
Pinson and Bazant simulate the evolution of the battery interphase layer by modeling the concentration gradients of lithium through the solid-electrolyte interphase. They claim that this is the first time anyone attempts a theoretical prediction of the spatio-temporal distribution of solid-electrolyte interphase formation in a porous electrode.
They add that their model, although quite simple, is able to accurately fit a wide range of published experimental data. The challenge here is to apply theory into practice and establish the real predictive value for battery research.
Via: Technology Review