About the in-plane distribution of the reaction rate in lithium-ion batteries

Abstract

Reaction rate distribution and current density distribution of Li-ion batteries largely determine the local aging and heat generation. Homogenous distribution contributes to better durability and safety of Li-ion batteries. This paper focuses on modeling the in-plane distribution of electrochemical reaction current, and the general equation relating space derivatives of the overvoltage to the electrochemical and electronic current densities is derived. Furthermore, this work investigates the impact of various battery parameters on the distribution by considering the cylindrical battery, one of the most used battery types. An explicit closed-form solution for a short time after the current supplied is obtained. It is found that the dimensions of cylindrical batteries, tabbing design, parameters of current collectors, and electrode materials are all indicated to affect the current density distribution. The electronic current density distribution is also demonstrated. This model and related analyses are incredibly beneficial for further optimizing Li-ion batteries’ electronic and electrode properties and as interesting cases for testing battery modeling tools.